| 单词 | thorium |
| 例句 | Scientists used a precise dating system based on the radioactive decay of uranium isotopes into thorium to assess the age of the paintings. Primitive art: Neanderthals were Europe's first painters 2018-02-22T05:00:00Z Scientists used a precise dating system based on the radioactive decay of uranium isotopes into thorium to assess the age of the paintings. Primitive art: Neanderthals were Europe's first painters 2018-02-22T05:00:00Z It forms through the radioactive decay of uranium and thorium deep in the crust and eventually seeps out and escapes into space. Impending sale of scientifically critical helium sparks worries 2023-11-05T04:00:00Z Other elements such as iodine and thorium, which are needed to sustain life on earth, are also likely to be amongst the material ejected by the explosion, also known as a kilonova. Massive space explosion observed creating elements needed for life 2023-10-25T04:00:00Z This came after Lynas proposed a method to draw out thorium, the radioactive element, from raw feedstock and from over a million tons of waste accumulated at its refinery. Activists demand transparency over Malaysia’s move to extend Lynas Rare Earth’s operations 2023-10-25T04:00:00Z Science and technology minister Chang Lih Kang said Lynas will be allowed to import radioactive material and continue processing rare earths, provided the firm carries out thorium extraction to remove radioactive waste. Rare-earths miner Lynas jumps as Malaysia allows key plant extension 2023-10-25T04:00:00Z If successful, Chang said the waste can be disposed off quickly and the thorium can be commercialized and sold to nuclear plants overseas or to other industries. Malaysia gives nod for Australian miner Lynas to import, process rare earths until March 2026 2023-10-24T04:00:00Z They contend that the radioactive elements, which include thorium and uranium among others, are not in their natural forms but have been made more dangerous through mechanical and chemical processes. Australia’s Lynas to upgrade Malaysian rare earth refinery amid dispute over operating license 2023-10-20T04:00:00Z Contamination largely consists of low levels of uranium, thorium, radium and associated decay products. Cleanup cost for nuclear contamination sites has risen nearly $1 billion since 2016, report says 2023-10-17T04:00:00Z He said Lynas would need time to conduct a pilot study, before commercializing thorium, which can be sold for use in nuclear plants overseas and other industries. Activists demand transparency over Malaysia’s move to extend Lynas Rare Earth’s operations 2023-10-25T04:00:00Z That's how these metals produce energy without an external source: Uranium atoms, one at a time, morph into atoms of a different metal, thorium, through a process called radioactive decay. Will "godlike AI" kill us all — or unlock the secrets of the universe? Probably not 2023-08-12T04:00:00Z Over time, minerals accumulate energy as radioactive elements like uranium, thorium, and potassium decay and release radiation. When Greenland was green: Ancient soil from beneath a mile of ice offers warnings for the future 2023-07-23T04:00:00Z Rare earths are relatively abundant but occur in low concentrations and are usually found mixed together with one another, or with radioactive elements such as uranium and thorium. Explainer-China's rare earths dominance in focus after mineral export curbs 2023-07-05T04:00:00Z In this process, they produce specific isotopes of other radioactive elements such as thorium, protactinium and radium. The US will send depleted uranium munitions to Ukraine — an expert explains their health effects 2023-06-17T04:00:00Z Another is a gamma ray spectrometer, which like a Geiger counter can capture the radiation emitted by thorium, uranium, and potassium. Major U.S. geological survey aims to uncover minerals critical for batteries and microchips 2023-06-01T04:00:00Z In 2021, the Saudi Geological Survey issued a “certificate of appreciation” to the Beijing Research Institute of Uranium Geology for help in exploring uranium and thorium resources. Inside Saudi Arabia’s Global Push for Nuclear Power 2023-04-01T04:00:00Z In some cases, the agency is also conducting radiometric surveys, which detect natural radioactive emissions from rocks and soils containing elements like thorium and uranium. A government program hopes to find critical minerals right beneath our feet 2023-03-19T04:00:00Z Mining them also affects the environment, since their ores can be laced with radioactive materials such as thorium and uranium. Sweden finds rare earth deposits that could benefit Western consumers 2023-01-13T05:00:00Z They can contain radioactive uranium, thorium and radium along with toxic metals such as barium, cadmium and lead, according to the environmental group ManaSota 88. Pollution from Florida mining a concern with Hurricane Ian 2022-09-27T04:00:00Z Mantles for gas lanterns contain thorium, because it forms an oxide that can survive being heated to incandescence for long periods of time. College Physics for AP Courses 2015-08-12T00:00:00Z For example, a “new element” produced by the radioactive decay of thorium was initially given the name mesothorium. Chemistry 2019-02-14T00:00:00Z Rare earths, a group of 17 elements near the bottom of the periodic table, are not radioactive, but radioactive contaminants like uranium and thorium occur naturally in rare earth deposits. A Supplier of Rare Earth Metals Turns to Greenland in Bid to Cut Reliance on Russia 2022-08-22T04:00:00Z It comes from the natural decay of uranium or thorium found in nearly all soils. Environmental Biology 2018-09-06T00:00:00Z Fertilizers are made from phosphate rock that contains naturally occurring uranium and thorium, which decay to radium, and radium decays to the radioactive gas radon, the Environmental Protection Agency says. Pollution from Florida mining a concern with Hurricane Ian 2022-09-27T04:00:00Z If an average lantern mantle contains 300 mg of thorium, what is its activity? College Physics for AP Courses 2015-08-12T00:00:00Z They are the uranium series, the actinide series, and the thorium series. Chemistry 2019-02-14T00:00:00Z It also holds uranium, thorium, and radium, and emits radon gas. Environmentalists target mountains of fertilizer waste 2022-04-20T04:00:00Z One leading theory, based on satellite observations, suggested that heat-producing radioactive elements such as potassium and thorium found in the lunar mantle might have driven the volcanism. China’s First Moon Rocks Ignite Research Bonanza 2022-03-17T04:00:00Z Those shifts show whether the rocks contain minerals like magnetite, and radiometric data measures substances like uranium, thorium, and potassium. In Colorado, locals question a survey for critical minerals 2021-11-19T05:00:00Z Some places have great natural concentrations of uranium and thorium, yielding doses ten times as high as the average value. College Physics for AP Courses 2015-08-12T00:00:00Z Based on orbital measurements, Oceanus Procellarum is thought to be enriched in radioactive potassium, uranium, and thorium—heat sources that would help melt magma in the Moon’s mantle and drive eruptions. China’s Moon rocks reveal puzzlingly persistent volcanic eruptions 2021-10-19T04:00:00Z Over time, that elemental uranium has partly decayed into thorium and protactinium. Did Nazis Produce These Uranium Cubes? Researchers Look for an Answer. 2021-09-10T04:00:00Z In the Journal of Analytical Atomic Spectrometry, researchers describe successfully detecting radioactive uranium and thorium hiding among something like a million billion other atoms. New Radioactivity Measurement Could Boost Precision of Dark Matter Experiments 2021-06-11T04:00:00Z Earlier surveys of the Wet Mountain Valley, which date to the 1950s and 60s, uncovered 400 to 500 occurrences of uranium and thorium in narrow veins, usually near rare earth elements. In Colorado, locals question a survey for critical minerals 2021-11-19T05:00:00Z Doses from the Earth itself are mainly due to the isotopes of uranium, thorium, and potassium, and vary greatly by location. College Physics for AP Courses 2015-08-12T00:00:00Z Steenkampskraal - a privately held company, says it plans to raise finance this year to restart an underground mine that previously produced thorium. Factbox: Miners gear up global rare earth projects as prices surge 2021-03-02T05:00:00Z “So when we measure the ratio of thorium to uranium in the cube, that is essentially a measure of the amount of time that has passed.” Did Nazis Produce These Uranium Cubes? Researchers Look for an Answer. 2021-09-10T04:00:00Z He and the other researchers pinpointed small concentrations of radioactive thorium and uranium in metallic samples by using a mass spectrometer, which separates particles based on their mass. New Radioactivity Measurement Could Boost Precision of Dark Matter Experiments 2021-06-11T04:00:00Z In vast swathes of the country, everyday rocks like granite and shale hold deposits of uranium, thorium and radium under the soil. There’s No Better Time to Clear the Air 2020-11-28T05:00:00Z “By sampling these, we will be able tell whether these are high thorium or not. And if not, that resets that whole question.” China Launches Moon Mission to Bring Back Lunar Rocks 2020-11-23T05:00:00Z Scientists also hope to learn more about the unusual composition of that region of the Moon, which contains rare earth elements, potassium, phosphorus, thorium and uranium. China's just-launched lunar mission will retrieve Moon rocks for the first time in 44 years 2020-11-23T05:00:00Z They found that dialing up the amount of thorium and uranium heats the mantle so much that it acts as an insulating blanket, preventing heat from escaping the liquid core. Stellar Smashups May Fuel Planetary Habitability, Study Suggests 2020-11-17T05:00:00Z That’s because heavy elements such as uranium and thorium are thought to be produced in collisions between neutron stars, and such collisions are more likely to occur in the densely crowded center of the galaxy. No star, no problem: Radioactivity could make otherwise frozen planets habitable 2020-04-01T04:00:00Z The scientists were looking for grains of zircon and monazite, tough minerals that survive for billions of years and, crucially, incorporate uranium and thorium atoms into their crystalline structure. Earth’s Oldest Asteroid Impact Found in Australia 2020-01-21T05:00:00Z If there is little thorium, “scientists will need to rethink how this young volcanic rock was created,” Dr. Xiao said. China Launches Moon Mission to Bring Back Lunar Rocks 2020-11-23T05:00:00Z Still, in the early days of nuclear chemistry, confirming the existence of thorium-230 was still a major contribution. Elizabeth Rona, the wandering polonium woman, changed radiation science forever 2020-01-05T05:00:00Z Radioactive uranium in the mineral slowly decays into thorium, so the team measured the levels of different isotopes of these elements. Animal painting found in cave is 44,000 years old 2019-12-12T05:00:00Z Radioactive uranium in the mineral slowly decays into thorium. Is this cave painting humanity’s oldest story? 2019-12-10T05:00:00Z Uranium and thorium decay, in a steady dribble over billions of years, into lead. Earth’s Oldest Asteroid Impact Found in Australia 2020-01-21T05:00:00Z The popcorn holds trace amounts of uranium, which over time decays into thorium at a fixed rate. World’s oldest hunting scene shows half-human, half-animal figures—and a sophisticated imagination 2019-12-11T05:00:00Z Over thousands of years, uranium in the ocean slowly and predictably breaks down into thorium, which then settles in the seafloor. Elizabeth Rona, the wandering polonium woman, changed radiation science forever 2020-01-05T05:00:00Z Granite contains a small amount of radioactive elements, such as uranium and thorium, which produce heat as they decay. Seeking New Energy, an English Town Digs Deep 2019-10-07T04:00:00Z Seiferle et al.2 observed a process known as internal conversion, in which a thorium-229 nucleus in the isomeric state decayed to the ground state and the neutral atom emitted an electron. One tick closer to a nuclear clock 2019-09-10T04:00:00Z The exposure of pregnant mothers to the pollutions of war, including uranium and thorium, irreversibly damages their unborn children. "The destruction of a society": First the U.S. invaded Iraq — then we left it poisoned 2019-09-07T04:00:00Z By analyzing the ratio of uranium to thorium in the mineral layer directly on top of the pigment, the researchers calculated the painting's minimum age: 44,000 years old, they report this week in Nature. World’s oldest hunting scene shows half-human, half-animal figures—and a sophisticated imagination 2019-12-11T05:00:00Z “We are working on these new generation nuclear reactors that use thorium instead of uranium, and thorium is not natively fissile, or radioactive. So the odds of a catastrophe drop precipitously.” The Democratic candidates are divided on nuclear energy 2019-09-05T04:00:00Z By comparing the ratios of specific helium, thorium and uranium isotopes in each mineral sample, the researchers calculated approximately how long ago the zircon crystals solidified and started to decay. America's largest asteroid impact left a trail of destruction across the eastern US 2019-08-16T04:00:00Z About 2% of the thorium ions were in the isomeric state. One tick closer to a nuclear clock 2019-09-10T04:00:00Z We found thorium, a product of depleted uranium decay, in the hair of Iraqi children with birth defects who lived in Nasiriyah and Ur City, near a U.S. military base. "The destruction of a society": First the U.S. invaded Iraq — then we left it poisoned 2019-09-07T04:00:00Z By contrast, natural background radiation – from thorium and uranium in rocks and other sources – is much, much higher. ‘Perhaps the most important isotope’: how carbon-14 revolutionised science 2019-08-10T04:00:00Z The presence of radioactive thorium in some ore is one example. Don't Panic About Rare Earth Elements 2019-05-31T04:00:00Z In this case, the researchers used a dating technique called uranium–thorium–helium dating, which looks at how radioactive isotopes, or versions, of uranium and thorium decay into helium. America's largest asteroid impact left a trail of destruction across the eastern US 2019-08-16T04:00:00Z Although the ultimate and groundbreaking goal of directly observing the thorium-229 isomeric transition remains elusive, substantial progress continues to be made. One tick closer to a nuclear clock 2019-09-10T04:00:00Z What is the significance of that conclusion, and what does the presence of thorium indicate about a child's health? "The destruction of a society": First the U.S. invaded Iraq — then we left it poisoned 2019-09-07T04:00:00Z From gold, platinum, and iridium, to thorium, uranium, and short-lived elements like plutonium. Gravitational Waves, Nuclear Fire, Rocks and Love 2019-05-05T04:00:00Z If a flowstone contains uranium, it will decay steadily — and at a predictable rate — into thorium. In Cave in Borneo Jungle, Scientists Find Oldest Figurative Painting in the World 2018-11-07T05:00:00Z He identified isotopes of cesium, thorium, uranium and plutonium, all the results of building nuclear weapons parts. Hidden danger: Radioactive dust is found in communities around nuclear weapons sites - Los Angeles Times 2018-09-28T04:00:00Z “This issue is not limited to mica, but instead affects any mineral containing the ubiquitous natural abundance of uranium and thorium,” he says. Hunt for dark matter turns to ancient minerals 2018-07-08T04:00:00Z Such high levels of thorium simply suggest high exposure at an early age and potentially in utero. "The destruction of a society": First the U.S. invaded Iraq — then we left it poisoned 2019-09-07T04:00:00Z Inhalation of the particles, which included uranium, thorium, plutonium and americium, can increase the risk of cancer. Study: Traces of radioactive contamination found in homes of six Hanford workers 2018-06-14T04:00:00Z In addition, they measured the natural uranium content of one of the rhino's teeth, since that element decays like clockwork into thorium. 700,000-Year-Old Stone Tools Point to Mysterious Human Relative 2018-05-02T04:00:00Z By comparing the ratios of uranium and thorium present in the bone, scientists can tell its age. Human finger bone points to an early exodus out of Africa 2018-04-09T04:00:00Z Freese acknowledges that uranium is a concern, although it's unclear whether the minerals that she and her team propose contain uranium or thorium contaminants. Hunt for dark matter turns to ancient minerals 2018-07-08T04:00:00Z We found uranium and thorium in these children’s teeth and hair. "The destruction of a society": First the U.S. invaded Iraq — then we left it poisoned 2019-09-07T04:00:00Z Kaltofen, through the course of his study, found three of the highest levels of thorium radioactivity in the dust of three Hanford workers’ homes. Study: Traces of radioactive contamination found in homes of six Hanford workers 2018-06-14T04:00:00Z Flowstones contain tiny amounts of uranium, which slowly breaks down into thorium. Neanderthals, the World’s First Misunderstood Artists 2018-02-22T05:00:00Z As in the 2012 study, the team determined the age of the paintings using a radiometric technique called uranium–thorium dating, which is based on the radioactive decay of uranium into thorium over time. Ancient Cave Paintings Clinch the Case for Neandertal Symbolism 2018-02-23T05:00:00Z When water percolates through soils into a cave, the waterborne uranium gets trapped in mineral crusts and radioactively decays at a predictable pace into thorium. World's Oldest Cave Art Found—And Neanderthals Made It 2018-02-22T05:00:00Z The electrons being looked at are inside molecules of thorium monoxide, which has some unique properties that make it suited to the search. Fundamental physics is frustrating physicists 2018-01-11T05:00:00Z While attending a conference on thorium energy production in Palo Alto, California, Brian met a man from the Seattle area who also supported nuclear energy. A lifetime of activism leads to focus on nuclear energy | Provided By Energy Northwest 2017-10-01T04:00:00Z The older a flowstone gets, the more thorium builds up inside it. Neanderthals, the World’s First Misunderstood Artists 2018-02-22T05:00:00Z The team then dated the rock using the relative levels of uranium and thorium isotopes in the calcite. Skeleton plundered from Mexican cave was one of the Americas’ oldest 2017-08-29T04:00:00Z Hoffmann's work relies on the fact that the radioactive element uranium dissolves in water, but the element thorium doesn't. World's Oldest Cave Art Found—And Neanderthals Made It 2018-02-22T05:00:00Z In the process, the company produced waste containing two radioactive elements, thorium and uranium, which it disposed of by dumping the waste into sewers and perhaps also by burying it, according to the federal plan. It’s a Superfund Site, but It’s Also Their Livelihood 2017-08-04T04:00:00Z The scientists finally contacted James B. Paces, a research geologist at the United States Geological Survey, who determined how much uranium in the bones had broken down into another element, thorium. Humans Lived in North America 130,000 Years Ago, Study Claims 2017-04-26T04:00:00Z The problem was that scientists usually needed big chunks to find enough uranium and thorium to measure. Neanderthals, the World’s First Misunderstood Artists 2018-02-22T05:00:00Z A third technique, which measures relative levels of radioactive uranium and thorium in bone, suggested that the remains are 130,000 years old. Controversial study claims humans reached Americas 100,000 years earlier than thought 2017-04-25T04:00:00Z Superfund money is helping clean up the thorium. What’s at Stake in Trump’s Proposed E.P.A. Cuts 2017-04-10T04:00:00Z Last year, the US army corps of engineers – which has assumed responsibility for cleaning up most of the area’s contaminated sites – confirmed it had found thorium-230 in residential and public property along the creek. Missouri home contaminated by wartime radioactive waste, lawsuit says 2016-11-16T05:00:00Z The mining unearthed a toxic and radioactive mix of chemical elements, including arsenic, molybdenum, selenium, uranium, radium and thorium. Mine cleanup at Riley Pass finally begins after 51 years 2016-08-07T04:00:00Z But thorium gloms on to particles more readily than protactinium. Crippled Atlantic currents triggered ice age climate change 2016-06-30T04:00:00Z Let's update the designs and further investigate the possibility using thorium as a fuel. Liberal Biases, Too, May Block Progress on Climate Change 2016-04-19T04:00:00Z The company says that it is considering ways to contain the thorium, and that it will lock up fluorine by converting it into a marketable mineral. Cold truths at the top of the world 2016-04-18T04:00:00Z We could have next-generation nuclear, thorium reactors that have no risk of meltdown. Transcript: The ‘Undercard’ Republican Presidential Debate 2015-10-28T04:00:00Z The team used the radioactive decay of uranium to thorium to date this stalagmite to 80,000 years ago—a minimum age for the teeth. Trove of teeth from cave represents oldest modern humans in China 2015-10-14T04:00:00Z Watts’s piece initially indicated that they also agreed on the merits of new approaches to nuclear power, including thorium reactors, although McKibben soon posted a comment saying that was mistaken. A Climate Campaigner (Bill McKibben) and Climate Change Critic (Anthony Watts) Meet in a Bar.... 2015-06-08T04:00:00Z Current reactors use uranium and water under high pressure; new ones could run on thorium, plutonium or more exotic materials, and in place of water might have molten metal. Betting on the Need, Scientists Work on Lighter, Cleaner Nuclear Energy 2014-12-15T05:00:00Z The room was constructed for additional hot-cell space back in the 1960s, when the DOE was considering building nuclear reactors that run on thorium. Nuclear power: Desperately seeking plutonium 2014-11-24T05:00:00Z Uranium decays into thorium at a specific rate and the team were able to calculate an accurate age of the painting by analysing levels of the two elements in the calcite. Cave art and harpoon tips show African roots of our creative genius 2014-10-11T04:00:00Z They also tested uranium and thorium contamination at multiple sites. Indonesian cave art may be world's oldest 2014-10-08T04:00:00Z The deposits contain low levels of radioactive uranium which decays into thorium at a known rate, providing an effective geological clock. Cave paintings in Indonesia suggest art came out of Africa 2014-10-08T04:00:00Z Because uranium decays into thorium at a known rate, the ratio of uranium to thorium isotopes in a sample indicates how old it is. World's oldest art found in Indonesian cave 2014-10-07T04:00:00Z Andrews-Hanna and colleagues note that the Procellarum region contains a lot of naturally occurring radioactive elements, such as uranium, thorium and potassium. Moon's hidden valley system revealed 2014-10-01T04:00:00Z Another advantage of the molten salt reactor is that it can run on thorium, making it unsuitable for weapons use and therefore possessing non-proliferation characteristics. Molten Salt Nuclear Reactors: Part Of America's Long-TermEnergy Future? 2014-09-22T04:00:00Z This was also the week that some blog called “The Auto Future” anointed thorium cars as the next in a long, long line of automotive “ways of the future”. The Weekly Oil And Gas Follies 2014-08-17T04:00:00Z Waste from atomic bomb production in downtown St. Louis was dumped in the creek in the 1940s, including uranium, thorium and radium. Study to see if cancer cluster exists 2014-07-19T04:00:00Z One of China’s nuclear power “moonshots” is a large research program in Shanghai to develop nuclear energy from thorium, as opposed to uranium. Xi Jinping Gives Nod To China’s Expansion of Nuclear Energy 2014-06-17T04:00:00Z Until thorium became marketable in the atomic age, the company dumped it into the sewers. Superfund Site Is Designated in Queens 2014-05-08T21:16:40Z Finally, Dewan observes that Transatomic Power’s reactor could run on thorium, but she believes it will be easier to obtain the uranium fuel. Molten Salt Nuclear Reactors: Part Of America's Long-TermEnergy Future? 2014-09-22T04:00:00Z And, finally, there’s thorium, a fuel source best suited to run in fourth generation “liquid fuel” reactor. Advanced Nuclear Energy Research Transcends Political Climate 2014-05-04T11:50:00Z Energy minerals focus on ores of uranium, thorium and helium-3 as materials useful for fission and fusion reactors. Fossil Fuels Still Rule But Don't Worry -- We Have Plenty Of Uranium 2014-04-07T04:47:00Z Much of the helium emitted at Yellowstone is helium-4, an isotope produced by radioactive decay of elements such as uranium and thorium in the crust. Helium high 2014-02-19T18:50:03.680Z The property is the former home of the defunct Wolff-Alport Chemical Company, which until 1954 extracted rare earth minerals from monazite sand, with the radioactive element thorium as a byproduct. Superfund Site Is Designated in Queens 2014-05-08T21:16:40Z The molten salt reactor and thorium salt reactor each have same safety features and fuel burn-up. Molten Salt Nuclear Reactors: Part Of America's Long-TermEnergy Future? 2014-09-22T04:00:00Z Critics of thorium, for example, say that it is still difficult to maintain high thermal efficiencies, which diminishes the economic case for those liquid fuel reactor’s over today’s technologies. Advanced Nuclear Energy Research Transcends Political Climate 2014-05-04T11:50:00Z Some hope exists for modular reactors or even thorium. Czech Project Shows Why Nuclear Power Is Fading Away 2013-12-06T19:46:00Z Podcast: the pros and cons of a thorium nuclear reactor. Physics Week in Review (All Saint's Edition): November 2, 2013 2013-11-03T04:15:03.350Z It is also more difficult to use thorium for the production of nuclear weapons. Thorium backed as a 'future fuel' 2013-10-31T09:41:38Z Forsberg takes pains to point out that the gas turbine approach could also be applied to molten salt technologies and thorium reactors to improve the economics. Molten Salt Nuclear Reactors: Part Of America's Long-TermEnergy Future? 2014-09-22T04:00:00Z “The world probably has enough spent nuclear fuel lying around to power reactors for hundreds of years, and there is literally four times as much thorium on the planet as uranium,” Lassiter says. The Case For Combating Climate Change With Nuclear Power and Fracking 2013-10-07T14:50:00Z Plutonium may cause certain problems, but thorium is an attractive alternative. Promise or problem? A debate on nuclear power 2013-06-06T18:45:02.507Z Others propose a thorium fuel cycle, yet other alternative reactor designs or even fusion, which seems to always be 50 years in the future. Pandora's Promise: The Triumph of Hope over Fear in Nuclear Power? 2013-06-04T17:45:00.340Z Hans Blix says the world should try its best to develop thorium His enthusiasm is shared by some in the British nuclear establishment. Thorium backed as a 'future fuel' 2013-10-31T09:41:38Z In the U.S., a small but growing community of advocates and investors is actively pushing for an MSR renaissance utilizing thorium or other fuel sources. Molten Salt Nuclear Reactors: Part Of America's Long-TermEnergy Future? 2014-09-22T04:00:00Z The latest result confirms that radium isotopes should be a good place to look for electric dipoles, and that some isotopes of thorium and uranium might be even better. Pear-Shaped Nucleus Boosts Search for Alternatives to 'Standard Model' Physics 2013-05-10T15:15:05.820Z Mined phosphate also tends to include radioactive elements, such as uranium, radium, radioactive lead, radon, thorium, polonium, and cadmium, because these are inescapable trace elements in phosphate ore extraction. Can Soil Replace Oil as a Source of Energy? [Excerpt] 2013-04-05T18:15:00.207Z Neutrinos are generated in stars, reactors, and deep in Earth’s crust and mantle by the radioactive decay of elements such as uranium and thorium. Detectors zero in on Earth’s heat 2013-04-03T17:20:20.957Z The company hopes to get thorium licensed alongside uranium in current water-cooled reactor plants. Thorium backed as a 'future fuel' 2013-10-31T09:41:38Z We’ve been seeing benefits of molten salt reactors independent of whether they run on thorium or uranium. Molten Salt Nuclear Reactors: Part Of America's Long-TermEnergy Future? 2014-09-22T04:00:00Z One ton of thorium has the same energy capacity as 6 million tons of coal. Test Tube Meat and 9 Other Innovations Changing Our World 2013-03-16T18:05:20Z China, India, Japan and France are working on molten salt and/or thorium. Letters: Nuclear power's place in a safer, cleaner Britain 2013-02-24T21:00:05Z Assuming that uranium and thorium are spread uniformly in the mantle, the KamLAND findings suggest that about 11 of the 47 TW come from the radioactive decay of those elements. Detectors zero in on Earth’s heat 2013-04-03T17:20:20.957Z The British government says it would be useful to increase the fuel options for nuclear operators, as thorium is believed to be three times more plentiful than uranium. Thorium backed as a 'future fuel' 2013-10-31T09:41:38Z As a consequence, a small number of analysts and companies are suggesting that it is time to re-evaluate various molten salt reactor technologies using thorium, spent nuclear fuel, or low enriched fuel. Molten Salt Nuclear Reactors: Part Of America's Long-TermEnergy Future? 2014-09-22T04:00:00Z While harmless by themselves, they are frequently found mixed with potentially dangerous radioactive ores such as thorium. Ex-Teacher Battles Mining Firm 2013-02-19T03:47:29Z Safe and efficient molten salt reactors, burning abundant thorium and/or nuclear waste will generate clean electricity cheaper than from coal, and their waste is virtually all short-term and valuable. Letters: Nuclear power's place in a safer, cleaner Britain 2013-02-24T21:00:05Z That could help scientists to discern between models that favour the uranium and thorium being spread throughout the mantle, versus those in which the elements are concentrated near the core–mantle boundary. Detectors zero in on Earth’s heat 2013-04-03T17:20:20.957Z China is going for a revolutionary approach, devising a next-generation reactor which its supporters say will enable thorium to be used much more safely than uranium. Thorium backed as a 'future fuel' 2013-10-31T09:41:38Z Coal generates radioactivity when it is burned releasing uranium and thorium, plus their decay products. Fugitive Fracking Gets Bum Rap 2013-02-18T06:00:14Z The report, which is not yet published, encourages development of unconventional alternatives such as "fast reactors" powered off nuclear waste, designs using thorium rather than uranium, and even fusion power. Report calls for huge expansion of experimental nuclear plants 2013-02-12T10:24:38Z Liquid fluoride thorium reactors are especially noteworthy in this regard and Richard Martin’s “Superfuel” does a very good job of explaining their function and advantages. Top 5 reasons why intelligent liberals don t like nuclear energy 2013-02-06T21:15:02.427Z "There are rare earths deposits that are troublesome, those containing sulphur and those containing radioactive substances such as uranium and thorium, and mining these elements in many countries is considered difficult to handle." New US rare earth centre to be built 2013-01-11T11:32:46Z I’m a lawyer not a scientist but in my opinion we should be trying our best to develop the use of thorium. Thorium backed as a 'future fuel' 2013-10-31T09:41:38Z Coal plants emit far more radioactive materials than nuclear plants do; each year a 1,000-megawatt coal plant disperses about 27 metric tons of uranium, thorium and other radioactive substances. No Nukes + No Fracking = More Coal? Indian Point Debate Highlights Green Quandary 2012-10-15T17:15:01.177Z Uranium 233 looked attractive because it could be made in a reactor from thorium, a cheap and abundant radioactive metal, and, almost magically, the reactor would produce more fuel than it consumed. Uranium 233 Disposal Proves a Problem 2012-09-24T01:56:06Z Environmental Protection Agency conducted a cleanup several years ago of polluted soil, hazardous wastes and piles of raw uranium and thorium ore. Idaho Wildfire Roars through Former Uranium Mine Site 2012-09-21T19:15:00.317Z Over time, the uranium in the crust decays into thorium. With Science, New Portrait of the Cave Artist 2012-06-15T17:04:39Z The Thor project represents an evolutionary approach, using thorium in existing reactors together with uranium or plutonium. Thorium backed as a 'future fuel' 2013-10-31T09:41:38Z The crusts incorporate small amounts of uranium, which decays into thorium over time. Oldest Cave Paintings May Be Creations of Neandertals, Not Modern Humans 2012-06-14T20:45:00.243Z U-series dating takes advantage of the fact that calcite, the form of calcium carbonate in stalactites and stalagmites, contains trace amounts of radioactive uranium-238, which decays to form atomic elements including radioactive thorium-230. Did Neandertals Paint Early Cave Art? 2012-06-14T20:30:00Z Over time, the uranium in the crust has decayed into thorium. New Dating Puts Cave Art in the Age of Neanderthals 2012-06-14T18:08:51Z Hence the need to consider possible sources of additional heat, like stores of radioactive potassium or thorium, or a fast-crystallizing inner core. Earth’s Core: The Enigma 1,800 Miles Below Us 2012-05-28T19:27:17Z There is lots of thorium in the world, very well distributed all over the globe. Thorium backed as a 'future fuel' 2013-10-31T09:41:38Z Gran Sasso's dolomite rock is very poor in uranium and thorium, the main sources of natural radioactivity. Gran Sasso: Chamber of physics 2012-05-23T21:50:23.633Z Helium is relatively abundant in many minerals, all of which are radioactive, and contain uranium or thorium as important constituents. Encyclopaedia Britannica, 11th Edition, Volume 13, Slice 2 "Hearing" to "Helmond" 2012-04-25T02:00:53.567Z A measure of the ratio of uranium to thorium gives the minimum age of the art just beneath the crust. New Dating Puts Cave Art in the Age of Neanderthals 2012-06-14T18:08:51Z The proposed fuel is thorium, an abundant silver-gray element named for the Norse god of thunder. Nuclear power entrepreneurs push thorium as a fuel 2012-02-20T20:55:26Z "The advantages of thorium are purely theoretical," he told BBC News. Thorium backed as a 'future fuel' 2013-10-31T09:41:38Z They also recommend developing and scaling up two types of advanced nuclear power plants: integral fast reactors and thorium reactors. A Practical Blueprint for a Low-Carbon Electric World? 2012-02-20T20:10:54Z Monazite, a phosphate of thorium and other rare earths, contains on the average about 1 cc. per gram. Encyclopaedia Britannica, 11th Edition, Volume 13, Slice 2 "Hearing" to "Helmond" 2012-04-25T02:00:53.567Z This conversation – “nuclear good but uranium dangerous” – regularly leads to a very good question: what about thorium? The Thing About Thorium: Why The Better Nuclear Fuel May Not Get A Chance 2012-02-16T23:59:05Z “Ninety-nine percent of the thorium is burned up,” he said. Nuclear power entrepreneurs push thorium as a fuel 2012-02-20T20:55:26Z More recently, Sir William has reported to the British Chemical Society that he has succeeded in obtaining carbon from four substances not containing this element—bismuth, hydro-fluo-silicic acid, thorium and zirconium. The Thirteenth Greatest of Centuries 2012-01-28T03:00:21.937Z The key elements the scientists were looking for were potassium and thorium. Planetary Mystery: How in the World Did Mercury Form? 2011-09-29T19:38:16Z But he adds that the rare earth deposit, near the village of Khan Neshin in Helmand Province, offers the added incentive of minable quantities of uranium, thorium, phosphate and limestone for cement. Afghanistan Holds Enormous Bounty of Rare Earths, Minerals 2011-09-29T17:45:05.640Z In the post-Cold War world, is there any hope for thorium? The Thing About Thorium: Why The Better Nuclear Fuel May Not Get A Chance 2012-02-16T23:59:05Z “There are small boatloads of fanatics on thorium that don’t see the downsides,” said Dan Ingersoll, senior project manager for nuclear technology at the Oak Ridge National Laboratory in Tennessee. Nuclear power entrepreneurs push thorium as a fuel 2012-02-20T20:55:26Z It is also a leader in developing fast breeder reactors that use thorium, a naturally occurring metal that is more abundant than uranium, less radioactive, and creates less waste. French Nuclear Explosion Causes India to Think Hard About Its Nuclear Ambitions 2011-09-19T16:06:06Z While rare earths themselves are not radioactive, they are always found in ore containing radioactive thorium and require careful handling and processing to avoid contaminating the environment. China Consolidates Control of Rare Earth Industry 2011-09-15T23:57:38Z Idaho also boasts a large vein deposit of thorium and rare earth metals. Is Thorium the Biggest Energy Breakthrough Since Fire? Possibly. 2011-09-11T22:29:54Z The presence of thorium, which is often found mixed with silicates, was the telltale marker of a particularly shallow volcano. Volcano on the moon's far side 2011-07-28T09:30:00Z He also pointed out that thorium would still have some radioactive byproducts — just not as much as uranium and not as long-lived — and that there is no ready stockpile of thorium in the United States. Nuclear power entrepreneurs push thorium as a fuel 2012-02-20T20:55:26Z There were two landfill dumps, a factory making luminous watch dials, drums of thorium were buried. Let the games begin 2011-07-22T19:30:01Z And Earth is chock full of such radioactive elements—primarily uranium, thorium and potassium. Nuclear Fission Confirmed as Source of More than Half of Earth's Heat 2011-07-18T22:45:00.247Z In China, the Atomic Energy of Canada Limited and a clutch of Chinese outfits began an effort in mid-2009 to use thorium as fuel in nuclear reactors in Qinshan, China. Is Thorium the Biggest Energy Breakthrough Since Fire? Possibly. 2011-09-11T22:29:54Z Despite the small number, the team estimates that about 4.3 million of the particles generated by the radioactive decay of uranium-238 and thorium-232 pass through each square centimeter of Earth's surface each second. Earth Still Retains Much of Its Original Heat 2011-07-17T18:00:00Z "Please forgive my ignorance," "but what is thorium?" Pick of the Parliamentary week 2011-07-08T10:20:24Z That refinery was processing ore with far more radioactive thorium contamination than the ore that Lynas will use. Malaysia Plan Meets Standards, U.N. Agency Says 2011-06-30T23:55:13Z Although rare earths are not radioactive, in nature they are usually found mixed with thorium — which is. The Fear of a Toxic Rerun 2011-06-30T00:20:10Z The most common source of thorium is the rare earth phosphate mineral, monazite. Is Thorium the Biggest Energy Breakthrough Since Fire? Possibly. 2011-09-11T22:29:54Z Even advanced nuclear reactors would need large, oil-burning machines to mine the uranium or thorium fuel. Why Shifting from Fossil Fuels to Cleaner Alternatives Will Require Fossil Fuels 2011-06-29T11:15:03.137Z With an initial kick from more traditional fissile materials, thorium can set up a self-sustaining “breeder” reaction that produces uranium 233, which is well suited to generation. World Changing Ideas: 20 Ways to Build a Cleaner, Healthier, Smarter World (preview) 2011-05-01T14:15:51.830Z Other materials have been used, such as zirconium, yttrium, and thorium oxides, and osmium and tantalum among the metals, but they have been displaced entirely by the materials mentioned above. The New Gresham Encyclopedia Volume 4, Part 2: Ebert to Estremadura 2011-04-14T02:00:56.200Z The apatite crystals contain uranium and thorium, which over millions of years decay radioactively, producing helium-4. Novel Technique Reveals How Glaciers Sculpted Their Valleys 2011-04-04T16:38:00Z Most also get rid of solid uranium-235 as a fuel, relying instead on different uranium isotopes, or liquid uranium mixtures, or even thorium as the primary fuel. Building a Better Reactor 2011-03-24T04:45:03Z It wasn't higher than, say, the black sands of southern India, which emits that level of natural back ground radiation because the sands are rich in thorium. Is Fukushima the New Chernobyl? 2011-03-15T17:31:12Z But the long-term storage of the Lynas plant’s radioactive thorium waste is still unresolved. Malaysia Makes a Big Bet on Crucial Metals 2011-03-08T14:25:46Z Another complication is that mining many of the materials also brings to the surface uranium and thorium, which are radioactive. Scientific Groups Call for New Sources of Rare Earths 2011-02-18T21:28:25Z Great Western expects to get licensing to store thorium, a radioactive byproduct of the mine, by the end of February. UPDATE 2-Great Western raises Rareco stake to 70 pct 2011-01-24T20:54:44Z After a long series of carefully conducted experiments on the compounds of uranium and thorium, she, with the intuition of genius, opened up to the world of science an entirely new field of research. Woman in Science With an Introductory Chapter on Woman's Long Struggle for Things of the Mind 2011-01-12T03:00:29.853Z Cox’s team analyzed the apatite in two ways—the amounts of uranium, thorium and helium it contained, and the number of “fission tracks” left by decaying uranium—to build a cooling history of the Gamburtsevs. ?Fossil? Mountains Entombed by Ice 2010-10-18T16:28:00Z The aim is to dilute it to a thorium concentration of less than 0.05 percent — the maximum permitted under international standards to allow the material to be disposed with few restrictions. Malaysia Makes a Big Bet on Crucial Metals 2011-03-08T14:25:46Z From standard references and technical manuals, Cummings learned how to extract thorium from commercially available tungsten electrodes by soaking them in a peroxide bath. Locked and Loaded: The Secret World of Extreme Militias 2010-09-30T08:45:00Z The Steenkampslraal mine, a former thorium mine owned by Rare Earth Extraction Co, contains 30,000 tonnes of total rare earth oxide at a concentration of 17 percent, Great Western said. UPDATE 1-Great Western Minerals shrs up on rare earth deal 2010-08-10T18:36:00Z But along the way, his company also designed a component for thorium reactors that it says would be useful in conventional uranium reactors as well. A Site for the Videos You Don't Want Everyone to See 2010-06-23T15:24:00Z But along the way, his company, now called Lightbridge, also designed a component for the thorium reactor that it says would be useful in conventional uranium reactors as well. Bridging 2 Kinds of Reactors 2010-06-23T13:30:00Z Geoneutrinos originate from the radioactive decay of uranium, thorium and potassium in the Earth's crust and mantle -- the thick layer extending to 1,800 miles below the surface. Discovery of Subatomic Particles Could Answer Deep Questions in Geology 2010-06-22T16:08:00Z According to the Centers for Disease Control, all three metals — uranium, thorium and beryllium — are highly toxic when ingested and cause cancer if inhaled as fine airborne particles. Locked and Loaded: The Secret World of Extreme Militias 2010-09-30T08:45:00Z Complete; not the partial liberation incidental to the nuclear fission of such unstable isotopes as those of thorium, uranium, plutonium, and so on. Triplanetary At first uranium and its compounds were the only known source of these new radiations, but many other substances were examined and two years later thorium and its compounds were added to the list. A Brief Account of Radio-activity But some isotopes of uranium and thorium have little beta, with some alpha and gamma, so Baxter concluded we had powdered uranium ore. The Blue Ghost Mystery It may be asked, how can this statement be reconciled with the fact that thorium and radium keep up their activity without any appreciable falling off with time. A History of Science, Volume 5(of 5) Aspects Of Recent Science A high thorium content in ore—you ask Prince. Astounding Stories of Super-Science April 1930 The mantle is made by dipping a cylinder of cotton net into a solution of nitrate of thorium and cerium, containing 99 per cent. of the former and 1 per cent. of the latter metal. How it Works Dealing in simple language with steam, electricity, light, heat, sound, hydraulics, optics, etc., and with their applications to apparatus in common use Boltwood discovered in uranium minerals the presence of a body which he named ionium, and which is so similar to thorium that it cannot be separated from it. A Brief Account of Radio-activity The mineral monazite is the source of the thorium and cerium compounds which, glowing intensely when heated, form the light-giving material of incandescent gas mantles. The Economic Aspect of Geology The discovery of the radio-active properties of uranium was followed about two years later by the discovery that thorium, and the minerals containing thorium, possess properties similar to those of uranium. A History of Science, Volume 5(of 5) Aspects Of Recent Science Some metals, as for instance, osmium, tantalum, thorium, and others, have been used, and others, also, with great success, so that the march of improvements is now going forward with rapid strides. Electricity for Boys A purified cotton fabric—or yarn—is treated with a concentrated solution of the mixed nitrates of thorium and cerium, and, after drying, the cellulose is burned away. Researches on Cellulose 1895-1900 The lead which is present in uranium and thorium minerals—apparently in fairly definite ratio to the amount of uranium and thorium—is found, on separation and purification, to possess radio-active properties. A Brief Account of Radio-activity Mesothorium, a by-product of the manufacture of thorium nitrate for gas mantles, is used as a substitute for radium in luminous paints and for therapeutic purposes. The Economic Aspect of Geology The substances uranium, thorium, polonium, radium, and their compounds are radioactive, radium being by far the most active. A History of Science, Volume 5(of 5) Aspects Of Recent Science Compounds of thorium, like those of radium, are found to possess radio-activity, but in a less degree. An Elementary Study of Chemistry De Mare in 1894, and Knofler in 1895, patented methods of preparing such cellulose threads containing the salts of thorium and cerium, by spinning a collodion containing the latter in solution. Researches on Cellulose 1895-1900 The bulk of the lead obtained from radio-active minerals differs in atomic weight from ordinary lead and appears also to be different according to whether its source is a thorium or a uranium mineral. A Brief Account of Radio-activity Before the war German commercial interests controlled most of the production, as well as the manufacture of the thorium products. The Economic Aspect of Geology It is a typical organic compound, one of the metal radical type, and contains one atom of thorium. The Black Star Passes These mantles contain the oxides of cerium and thorium in the ratio of about 1% of the former to 99% of the latter. An Elementary Study of Chemistry Kemp sliced another round block of thorium out of a near-by crystal and fitted the second wedge of plutonium into it. Rip Foster Rides the Gray Planet The sources or parents of these are the original uranium or thorium, and the products form regular series with distinctive properties for each member. A Brief Account of Radio-activity During the war, however, the United States became the largest manufacturer of thorium nitrate and gas mantles and exported these products in considerable quantity. The Economic Aspect of Geology Radium, uranium, thorium, actinium—all the radioactive elements—are, as everybody knows, continually disintegrating, discharging the enormous energy that is imprisoned in their molecules. The Man Who Rocked the Earth Two or three other elements, particularly uranium and thorium, have been found to possess many of the properties of radium in smaller degree. An Elementary Study of Chemistry Sixty minutes later, clean, fed, and contented, the Planeteers were again on the thorium planet while the Scorpius, riding the same orbit, stood by a few miles out in space. Rip Foster Rides the Gray Planet It is known now to be present in thorium minerals, in the waters of radio-active wells, and in minute amounts in the atmosphere. A Brief Account of Radio-activity An effort is now being made to secure protective legislation against German thorium products. The Economic Aspect of Geology The author has obtained metallic thorium by heating sodium with the double anhydrous thorium potassium chloride, in presence of sodium chloride in an iron crucible. Scientific American Supplement, No. 365, December 30, 1882 Give the derivation of the names of the following elements: thorium, gallium, selenium, uranium. An Elementary Study of Chemistry The other team was slanting away from them and would soon be out of sight behind the thorium crystals in which the cave was located. Rip Foster Rides the Gray Planet The conclusion was, therefore, that the activity was an inherent property of the atoms of uranium and thorium, that is, an atomic property. A Brief Account of Radio-activity Monazite is a mineral consisting of phosphates of cerium, lanthanum, thorium, and other rare earths in varying proportions. The Economic Aspect of Geology Fuming hydrochloric acid and aqua regia attack thorium readily, but the alkalies are without action. Scientific American Supplement, No. 365, December 30, 1882 The precipitate is thorium oxalate, which is washed with hot water, dried, and ignited. A Text-book of Assaying: For the Use of Those Connected with Mines. In a moment he stood aside and Koa lifted out a perfect ring of thorium. Rip Foster Rides the Gray Planet Similar results were obtained in the examination of thorium minerals and thorium salts. A Brief Account of Radio-activity The content of thorium oxide varies from a trace up to 30 per cent, and commercial monazite sands are usually mixed so as to bring the grade up to at least 5 per cent. The Economic Aspect of Geology The mean specific gravity of pure thorium is about 11. Scientific American Supplement, No. 365, December 30, 1882 The only elements so far known that undergo spontaneous change are uranium and thorium. The Breath of Life I knew this asteroid was thorium, and that thorium is radioactive. Rip Foster Rides the Gray Planet The first investigations of the activity of uranium and thorium showed no loss of intensity at the end of several years, and radium also seemed to show no decrease in its enormous activity. A Brief Account of Radio-activity I knew this asteroid was thorium and that thorium is radioactive. Rip Foster in Ride the Gray Planet Mantles are made by knitting cylinders of cotton or of other fiber and soaking these in a solution of the nitrates of cerium and thorium. Artificial Light Its Influence upon Civilization The German method of making the lamp filaments is to squirt a mixture of tungsten powder and thorium oxide through a perforated diamond of the desired diameter. Creative Chemistry Descriptive of Recent Achievements in the Chemical Industries Pederson searched the gray metal with his torch and found a slender spur of thorium perhaps two feet high a short distance from the boat. Rip Foster Rides the Gray Planet Thus a metal plate or wire exposed to the action of thorium oxide for some hours became itself active. A Brief Account of Radio-activity As his men looked at each other in surprise at the quickness of it, he continued, "The old bucket found something we need—an asteroid of pure thorium." Rip Foster in Ride the Gray Planet We can only, from known results obtained with larger specimens of just such a mineral substance as composes the nucleus, guess at the amount of uranium, or it may be thorium, which may be present. The Birth-Time of the World and Other Scientific Essays Since the monazite contains more cerium than thorium and the mantles made from it contain more thorium than cerium, there is a superfluity of cerium. Creative Chemistry Descriptive of Recent Achievements in the Chemical Industries Rip ordered it covered as much as possible with the thorium that had been taken from the hole. Rip Foster Rides the Gray Planet Similar phenomena were observed when radium was substituted for thorium. A Brief Account of Radio-activity In a moment he stood aside, and Koa lifted out a perfect ring of thorium. Rip Foster in Ride the Gray Planet It may be observed respecting this theory that there is some support for the view that a parent substance both to uranium and thorium has existed or possibly exists. The Birth-Time of the World and Other Scientific Essays The chief sources of the material for the Welsbach burners is monazite, a glittering yellow sand composed of phosphate of cerium with some 5 per cent. of thorium. Creative Chemistry Descriptive of Recent Achievements in the Chemical Industries They reached the peaks of thorium and Rip looked them over. Rip Foster Rides the Gray Planet So, too, in the case of thorium salts a substance can be obtained by means of ammonium hydroxide which is several thousand times more active than an equal weight of the original salt. A Brief Account of Radio-activity Sixty minutes later, clean, fed, and contented, the Planeteers were again on the thorium planet, while the Scorpius, riding the same orbit, stood by a few miles out in space. Rip Foster in Ride the Gray Planet Nothing is, on the other hand, known respecting the origin of uranium or thorium—the parent radioactive bodies. The Birth-Time of the World and Other Scientific Essays The manufacturers give away a pound of cerium salts with every purchase of a hundred pounds of thorium salts. Creative Chemistry Descriptive of Recent Achievements in the Chemical Industries A particularly high crystal of thorium had snagged the craft. Rip Foster Rides the Gray Planet After standing a month, the separated material has lost its activity and the thorium salt has regained it. A Brief Account of Radio-activity Pederson searched the gray metal with his torch and found a slender spur of thorium, perhaps two feet high, a short distance from the boat. Rip Foster in Ride the Gray Planet It shows to relatively correct scale the limiting range of all the alpha-ray producing members of the uranium and thorium families. The Birth-Time of the World and Other Scientific Essays When certain substances, such as thorium and cerium, are heated, they do not melt or vaporize, but glow with an intense bright light. General Science In the case of compounds of thorium Professor Rutherford discovered a similar phenomenon; since then, various physicists, Professor Soddy, Miss Brooks, Miss Gates, M. Danne, and others, have studied the properties of these emanations. The New Physics and Its Evolution The bodies obtained in the above experiments were named uranium X and thorium X, respectively. A Brief Account of Radio-activity Kemp sliced another round block of thorium out of a nearby crystal and fitted the second wedge of plutonium into it. Rip Foster in Ride the Gray Planet Fletcher, A. L., proportionality of thorium and uranium, 26, The Birth-Time of the World and Other Scientific Essays Compounds of only two of these substances, uranium and thorium, are radio-active. The Story of Alchemy and the Beginnings of Chemistry In the same way, Professors Rutherford and Soddy have discovered a so-called thorium X to be the stage through which ordinary thorium has to pass in order to produce its emanation. The New Physics and Its Evolution From thorium minerals a body was separated called mesothorium, which was analogous to radium. A Brief Account of Radio-activity The other two men slanted away from them and would soon be out of sight behind the thorium crystals in which the cave was located. Rip Foster in Ride the Gray Planet We have seen that our examination of the rocks reveals only the two sorts of halo: the radium halo and the thorium halo. The Birth-Time of the World and Other Scientific Essays The minute particles of two of the substances for many years classed as elements give off electrons; uranium and thorium are radio-active. The Story of Alchemy and the Beginnings of Chemistry Now, no compound containing any other active metal than uranium or thorium ought to show itself more active than those metals themselves, since the property belongs to their atoms. The New Physics and Its Evolution Both thorium and radium were found to give off a radio-active gas. A Brief Account of Radio-activity "It's important," O'Brine continued, "because it happens to be pure thorium." Rip Foster in Ride the Gray Planet The particle in the centre of the halo contains uranium or thorium, and, necessarily, along with the parent substance, the various elements derived from it. The Birth-Time of the World and Other Scientific Essays Shortly after Becquerel's discovery, experiments proved that salts of the rare metal thorium are radio-active. The Story of Alchemy and the Beginnings of Chemistry As regards thorium the results are less satisfactory. The New Physics and Its Evolution Certainly, it is possessed in varying degree by four of the old elements widely separated in the Periodic System, namely, uranium, thorium, rubidium, and potassium. A Brief Account of Radio-activity They reached the peaks of thorium, and Rip looked them over. Rip Foster in Ride the Gray Planet If uranium and thorium are really primary elements, however, the analogy relied on may be misleading; at least, it is obviously incomplete. The Birth-Time of the World and Other Scientific Essays Monaxite, a heavy yellow sand, the ore of thorium, is found here, and is in considerable demand on account of the new discoveries in the radio activity of certain minerals. Final Report of the Louisiana Purchase Exposition Commission Since the above was written, another product has been found to intervene between the X substance and the emanation in the case of actinium and thorium. The New Physics and Its Evolution The decrease and rise of activity, for example, of uranium and uranium X, and also of thorium and thorium X, have been measured, plotted, and the equations worked out. A Brief Account of Radio-activity A particularly high crystal of thorium had snagged the landing craft. Rip Foster in Ride the Gray Planet However, as we have seen, the view that thorium gives rise to stable lead is beset with some difficulties. The Birth-Time of the World and Other Scientific Essays Iridium, osmium, platinum, ruthenium, tantalum, thorium, tungsten, uranium. Scientific American Supplement, No. 799, April 25, 1891 Radium and thorium possess in somewhat large proportions the three kinds of rays, and it is the same with actinium. The New Physics and Its Evolution In this class are now placed also the three radio-active gases, emanating respectively from radium, thorium, and actinium. A Brief Account of Radio-activity They would have to be mounted in thorium in order to keep them rigid. Rip Foster in Ride the Gray Planet The thorium and uranium ores are, again, specially prone to alteration. The Birth-Time of the World and Other Scientific Essays How much thorium, not to speak of cerium, could they take at a maximum. Tono Bungay In the case of thorium-232, for example, radioactive decay proceeds so slowly that 14 billion years must elapse before one-half of an initial quantity decayed to a more stable configuration. Worldwide Effects of Nuclear War: Some Perspectives These are generally known as radium emanation, thorium emanation, and actinium emanation. A Brief Account of Radio-activity The Scorpius had sent piloted snapper-boats over the asteroid at high speed, crisscrossing in order to cover the thorium world completely, expecting to have the unknown rocketeer fire at them. Rip Foster in Ride the Gray Planet One of my assistants was demonstrating a peculiar property of thorium and Deverill seemed interested. A Christmas Mystery The Story of Three Wise Men Radium gives off three distinct types of rays named after the first three letters of the Greek alphabet—Alpha, Beta, Gamma—besides a gas emanation as does thorium which is a powerfully radio-active substance. Marvels of Modern Science In 1899 E. Rutherford, then of Montreal, discovered that the radiation from uranium, thorium and radium was complex. Darwin and Modern Science Furthermore, in the thorium series 6 alpha particles are lost before reaching the end product, which again is perhaps the chemical analogue of lead. A Brief Account of Radio-activity Uranium certainly is; thorium—the stuff of this incandescent gas mantle—certainly is; actinium. The World Set Free Two active deposits, thorium A and B, arise successively from the emanation. Darwin and Modern Science This is true also of the two other elements found in the ores of uranium and thorium, viz., polonium and actinium. Marvels of Modern Science As we have said above, solid bodies exposed to the emanations of radium or thorium become coated with a radio-active deposit. Darwin and Modern Science Determinations of the atomic weight of lead from thorite, a thorium mineral nearly free from uranium, gave 208.4. A Brief Account of Radio-activity These bodies behave differently from their parents uranium and thorium, and show all the signs of distinct chemical individuality. Darwin and Modern Science They are strongly radio-active, while, after the separation, the parents uranium and thorium are found to have lost some of their radio-activity. Darwin and Modern Science If the X-substances be kept, their radio-activity decays, while that of the uranium or thorium from which they were obtained gradually rises to the initial value it had before the separation. Darwin and Modern Science Here thorium-X is interposed between thorium and its short-lived emanation, which decays to half its initial quantity in 54 seconds. Darwin and Modern Science Radio-active Products in the Earth's Crust The presence of uranium and thorium widely distributed throughout the crust of the earth would lead to the conclusion that their disintegration products would be found there also. A Brief Account of Radio-activity Radium and thorium, but not uranium, give rise to radio-active gases which have been called emanations. Darwin and Modern Science A somewhat similar pedigree has been made out in the case of thorium. Darwin and Modern Science No place is found in this pedigree for thorium and its derivatives. Darwin and Modern Science |
| 随便看 |
|
英语例句辞典收录了117811条英语例句在线翻译词条，基本涵盖了全部常用单词及词组的例句翻译及用法，是英语学习的有利工具。