| 单词 | isotopic |
| 例句 | So Forsyth and her colleagues used a method called isotopic analysis, which uses chemical clues to definitively determine the source of lead. The vice of spice: confronting lead-tainted turmeric 2023-08-02T04:00:00Z She was about 15, but her skeleton hasn't yet been subjected to radiocarbon dating or isotopic analysis. UK experts find 7th-century teen buried in her bed 2012-03-16T17:51:10Z The scientists analyzed the chemical makeup and carbon isotopic composition of the microfossils and determined the carbon was created by living organisms, confirming that the structures were indeed biologic fossils. Window to the past: New microfossils suggest earlier rise in complex life 2023-11-07T05:00:00Z Among other things, the researchers determined the isotopic and elemental composition of the calcareous shells of plankton. How salt from the Caribbean affects our climate 2023-11-03T04:00:00Z Each water molecule that is part of the cycle has a certain isotopic 'fingerprint,' or composition, which reflects small variations in the atomic weight of the oxygen and hydrogen atoms that comprise the molecule. Study links changes in global water cycle to higher temperatures 2023-11-02T04:00:00Z Different plants have distinct carbon isotopic signatures, which can provide information about past plant communities. Climate and human land use both play roles in Pacific island wildfires past and present 2023-10-02T04:00:00Z In this study, the researchers combined NanoSIMS with stable isotope labeling, to visualize isotopic variations within tissues at high resolution, providing insights into the metabolic activity of individual cellular compartments and organelles. A deep look into the progression of Parkinson's Disease 2023-09-29T04:00:00Z They compared the hydrogen isotopic composition of aquatic plant waxes within the sediment to biomarkers from terrestrial plants and other sources. Ancient plant wax reveals how global warming affects methane in Arctic lakes 2023-09-29T04:00:00Z According to Conrad, turtle shells grow in a sequential style, similar to tree rings, and record isotopic elements such as uranium-236 from spent nuclear fuel. Researchers find nuclear fingerprints in sea turtle shells 2023-09-02T04:00:00Z Global scale relationships between temperature and the isotopic composition of certain environmental waters, like seawater and glacial ice, have long been recognized as the planet moves in and out of ice age cycles. Study links changes in global water cycle to higher temperatures 2023-11-02T04:00:00Z Retail executives and testing companies told Reuters that isotopic analysis is often used to verify that suppliers are only using cotton sourced from approved locations, such as the U.S. or India. Exclusive: US Customs finds garments made with banned Chinese cotton -documents 2023-09-01T04:00:00Z So far, only one of the anomalous spherules has the isotopic pattern in its iron expected if it was heated by a fiery passage through the atmosphere. Did interstellar debris fall to the sea floor? Claim meets sea of doubt 2023-08-30T04:00:00Z Next, the researchers looked for telltale isotopic signatures. Germany’s radioactive boars are a bristly reminder of nuclear fallout 2023-08-30T04:00:00Z Turtle shells grow in a sequential style, similar to tree rings, and record isotopic elements such as uranium-236 from spent nuclear fuel. Researchers find nuclear fingerprints in sea turtle shells 2023-09-02T04:00:00Z But this study provides the first evidence that temperature and the isotopic composition of environmental waters go hand in hand at timescales in between these two -- that is, over decades to centuries. Study links changes in global water cycle to higher temperatures 2023-11-02T04:00:00Z Officials said isotopic testing alone is not enough to clear shipments detained at U.S. ports for suspected links to Xinjiang. Exclusive: US Customs finds garments made with banned Chinese cotton -documents 2023-09-01T04:00:00Z He wants to look for other isotopic variations in trace elements such as neodymium, which could indicate formation around another star. Did interstellar debris fall to the sea floor? Claim meets sea of doubt 2023-08-30T04:00:00Z But in 2014 data from the European Space Agency's Rosetta mission showed that many comets' isotopic ratio is way off—they have far more deuterium than terrestrial water does. Did Earth’s Water Come from Meteorites? 2023-07-31T04:00:00Z A definitive answer will emerge from studying the isotopic signatures embedded within the spherules. Have We Found Fragments of a Meteor from Another Star? 2023-07-05T04:00:00Z "The isotopic signals in these waters are very responsive to temperature changes." Study links changes in global water cycle to higher temperatures 2023-11-02T04:00:00Z Many retailers have also turned to isotopic testing in a bid to keep their supply chain free of cotton with links to forced labor. Exclusive: US Customs finds garments made with banned Chinese cotton -documents 2023-09-01T04:00:00Z Hofmann will use a special kind of mass spectrometer called an Orbitrap to identify specific organic molecules with different isotopic compositions within her samples and compare their amounts. Pebbles from an Asteroid Are about to Be Delivered to Earth, and It’s Totally Awesome 2023-06-17T04:00:00Z Thus, an isotopic comparison of Europa to one or both of the outermost moons could finally reveal the truth about how these satellites diverged from their common origins. Jupiter’s Hot Youth May Have Melted Its Icy Moons 2023-04-24T04:00:00Z This isotopic analysis is currently underway at the University of California, Berkeley, and will soon begin at Harvard University. Have We Found Fragments of a Meteor from Another Star? 2023-07-05T04:00:00Z The researchers interpreted these isotopic changes and determined their timeline by synthesizing data from across a wide variety of natural archive sources from the past 2,000 years of Earth history. Study links changes in global water cycle to higher temperatures 2023-11-02T04:00:00Z And ultimately, understanding the movements of horses through isotopic and genetic analyses could help trace human migration during a tumultuous period. Horse nations: Animal began transforming Native American life startlingly early 2023-03-29T04:00:00Z Animals feeding in a particular location then retain that isotopic fingerprint in their tissues. Whale skin provides clues to elusive migration habits 2023-02-26T05:00:00Z They found that the potassium in the noncarbonaceous rocks showed isotopic patterns quite similar to those seen on Earth. Earthlike planets should readily form around other stars, meteorites suggest 2023-01-25T05:00:00Z It features what appear to be scanned printouts of manually typed tables containing the isotopic data from the fish fossils. Paleontologist accused of faking data in dino-killing asteroid paper 2022-12-06T05:00:00Z “We’ve made a concerted effort to bring together information from historical accounts, archaeology, bioarchaeology and isotopic analyses to contextualize the genetic data. It’s amazing what we can learn when we weave diverse lines of evidence.” Paid to Fight, Even in Ancient Greece 2022-10-04T04:00:00Z Seventy years later, the fallen warriors all had very similar genetic and isotopic signatures, supporting historical accounts that the Himerans fought that second battle unaided, likely contributing to their defeat. Mercenaries may have helped ancient Greeks turn the tide of war 2022-10-02T04:00:00Z Yet the isotopic signal cannot distinguish between microbes in a swamp, a landfill, or a cow’s gut. In ominous sign for global warming, feedback loop may be accelerating methane emissions 2022-07-12T04:00:00Z The isotopic signatures also suggested each zone was fed by material forged in different ancient and distant sources, such as supernovae and red giant stars. Earthlike planets should readily form around other stars, meteorites suggest 2023-01-25T05:00:00Z Cochran says the format of the isotopic data does not appear unusual. Paleontologist accused of faking data in dino-killing asteroid paper 2022-12-06T05:00:00Z It was only in the early part of the 20th century, when isotopic dating methods were first applied, that it became possible to discover the absolute ages of the rocks containing fossils. Physical Geology 2015-01-01T00:00:00Z Combining DNA and isotopic studies, he says, “provides another data point beyond what history and archaeology can give us.” Mercenaries may have helped ancient Greeks turn the tide of war 2022-10-02T04:00:00Z One way we know that the increased greenhouse gas emissions are from human activities is with isotopic fingerprints. An Introduction to Geology 2017-01-01T00:00:00Z Until recently, scientists were only able to detect the early isotopic fingerprints in metals such as chromium, titanium, and molybdenum, which are durable enough to have resisted the heat of the newborn Sun. Earthlike planets should readily form around other stars, meteorites suggest 2023-01-25T05:00:00Z As plants absorb those nutrients, they incorporate “those isotopic signatures,” he explained. Fred the Mastodon’s Tusks Reveal a Life of Fighting and Roaming 2022-06-13T04:00:00Z That information was not available until the development of isotopic dating techniques early in the 20th century. Physical Geology 2015-01-01T00:00:00Z The remains of a man had an isotopic signature more typical of the Southern Uplands, Southern Highlands or Loch Lomond area. Research sheds new light on ancient bones found at Cramond 2022-03-28T04:00:00Z However, it is hard to know if Earth processes could have changed the water’s isotopic signature over the last 4-plus billion years. An Introduction to Geology 2017-01-01T00:00:00Z But early searches for isotopic evidence that Earth’s lighter volatile elements also originated nearby came up dry. Earthlike planets should readily form around other stars, meteorites suggest 2023-01-25T05:00:00Z “I actually started typing him an email from my phone from the back of the room, saying, ‘Hey, if you have these fishes, can we please do isotopic analysis on their bones?’” The Dinosaur Age May Have Ended in Springtime 2022-02-23T05:00:00Z The researchers also measured the isotopic carbon incorporated into the fish’s bones. Springtime was the season the dinosaurs died, ancient fish fossils suggest 2022-02-23T05:00:00Z Carbon exists in two stable isotopic forms: “light” carbon-12, which makes up the vast majority of carbon, and carbon-13, which is weighed down by an extra neutron. Mars rover detects carbon signature that hints at past life source 2022-01-16T05:00:00Z They resemble volcanic glass but, unlike volcanic glass, tektites contain no water or phenocrysts, and have a different bulk and isotopic chemistry. An Introduction to Geology 2017-01-01T00:00:00Z After the first 7 years of the experiment, the researchers stopped adding the isotopic mercury and continued to check the concentrations in the animals living in the lake. Research in experimental lake shows fish populations can recover quickly from mercury contamination 2021-12-15T05:00:00Z Telltale isotopic signatures indicate that it likely starved to death near the foothills of the Brooks Range. Mammoth Tusk Analysis Reveals Epic Lifetime Journey around Alaska 2021-09-09T04:00:00Z “We haven’t been able to see that before in regular isotopic analysis,” Rowan says. Ancient Roman vacationers consumed gobs of olive oil and fish, volcano victims reveal 2021-08-25T04:00:00Z The gas was then probed by a laser, which revealed the methane’s isotopic makeup. Mars rover detects carbon signature that hints at past life source 2022-01-16T05:00:00Z Studies have been using isotopic carbon signatures to identify anthropogenic carbon in the atmosphere since the 1980s. An Introduction to Geology 2017-01-01T00:00:00Z During the next 8 years of the study, concentrations of isotopic mercury dropped by up to 91% in the small fish. Research in experimental lake shows fish populations can recover quickly from mercury contamination 2021-12-15T05:00:00Z "Mass spectrometry describes the analysis in nuclear science of the isotopic content of chemical samples and, in particular, the concentration measurements of these elements using isotope dilution techniques," Channing D. Phillips, the acting U.S. Iranian national living in Canada charged in alleged plot to export equipment used for uranium enrichment 2021-07-31T04:00:00Z This isotopic signature is locked in tooth enamel in the first years of an animal’s life and remains unchanged even if the animal later moves to a foreign land. 3300-year-old baboon skull may tell of mysterious ancient kingdom 2020-12-15T05:00:00Z One possibility is that the zircons containing certain isotopic ratios are bigger, denser, or bulkier, which affects their movement, Dr. Barfod said. The Romans Called it ‘Alexandrian Glass.’ Where Was It Really From? 2020-07-31T04:00:00Z Isotopic records from the Antarctic Ice Sheet show stable isotopic signature from ~1000 AD to ~1800 AD and a steady isotopic signature gradually changing since 1800 followed by rapid change after 1950. An Introduction to Geology 2017-01-01T00:00:00Z They’re also thinking about new experiments, such as burning some of the forest around the lake or flooding an adjacent wetland, both of which could trigger the release of more isotopic mercury. Research in experimental lake shows fish populations can recover quickly from mercury contamination 2021-12-15T05:00:00Z The importance of this recycled moisture for nourishing rains was largely disregarded until 1979, when Brazilian meteorologist Eneas Salati reported studies of the isotopic composition of rainwater sampled from the Amazon Basin. A controversial Russian theory claims forests don’t just make rain—they make wind 2020-06-18T04:00:00Z Researchers also could study whether lead from English and German mines has distinctive isotopic signatures; if so, isotopes in the ice record could settle which region polluted most. Lead pollution in ancient ice cores may track the rise and fall of medieval kings 2020-03-30T04:00:00Z So her group is seeking to match the wood’s isotopic makeup to that of soil in likely locations. Scientists are leading Notre Dame’s restoration—and probing mysteries laid bare by its devastating fire 2020-03-12T04:00:00Z Surprisingly, the inferred isotopic composition of ruthenium in the material does not match known meteorite compositions. Ancient rock bears isotopic fingerprints of Earth’s origins 2020-03-10T04:00:00Z Whiskies claimed to be from the 19th century are revealed to be made with much more recently grown barley thanks to the unique isotopic fingerprint of the nuclear testing era. Fingering Fake Whiskies With Isotopes 2020-02-06T05:00:00Z Geologists date events using “isotopic clocks” in minerals like zircon and monazite. The world’s oldest asteroid strike in Western Australia may have triggered a global thaw 2020-01-21T05:00:00Z However, its data are helping calibrate other, indirect methods of measuring ancient CO2, like using isotopic shifts in single-celled foraminifera fossils. World’s oldest ice core could solve mystery of ‘flipped’ ice age cycles 2019-10-30T04:00:00Z Two days after the explosion, Rosatom, the Russian nuclear agency, said it occurred as a result of a test involving “isotopic sources of fuel on a liquid propulsion unit.” Russia Stops U.S. Diplomats en Route to a Nuclear Accident Site 2019-10-16T04:00:00Z Are nucleosynthetic fingerprints observed in the isotopic compositions of other elements in the mantle? Ancient rock bears isotopic fingerprints of Earth’s origins 2020-03-10T04:00:00Z Urey’s continuing work on stable isotopes of other chemical elements, such as nitrogen and oxygen, led to important applications in biochemistry and geochemistry, including the pioneering use of isotopic labels to study metabolic pathways. From bomb to Moon: a Nobel laureate of principles 2019-10-13T04:00:00Z After impact, the isotopic clocks start ticking again as new lead accumulates. The world’s oldest asteroid strike in Western Australia may have triggered a global thaw 2020-01-21T05:00:00Z “We added a new aspect to the current state of the art: the integration of genetic, isotopic and archaeological data, which helped us understand the complexity of past social structures,” Stockhammer says. Ancient Teeth Reveal Social Stratification Dates Back to Bronze Age Societies 2019-10-11T04:00:00Z “In both cases, the last representatives of these populations showed significant changes in their isotopic composition, indicating changes in their environment shortly before they became locally extinct.” How the woolly mammoth extinction took place on remote Arctic island 2019-10-07T04:00:00Z And how was the isotopic signature of these meteorites preserved in the convecting mantle? Ancient rock bears isotopic fingerprints of Earth’s origins 2020-03-10T04:00:00Z However, in 2018, a close passage of the comet 46P/Wirtanen allowed planetary scientists a more detailed look at its isotopic make-up using SOFIA, a jumbo jet with a telescope on board—very cool. How Did Water Get On Earth? 2019-10-06T04:00:00Z Woodhead and colleagues present a compilation of newly acquired and previously published neodymium and hafnium isotopic data, measured on archetypal kimberlites. Enigmatic origin of diamond-bearing rocks revealed 2019-09-24T04:00:00Z Dansgaard, for instance, had begun collecting rainwater in his Copenhagen backyard in mid-1952 to show the isotopic profile of a local storm. Making the planetary personal: the roots of climate science 2019-09-16T04:00:00Z Plants and animals leave different chemical traces in the hair, bone, and teeth of the living things that eat them, readable as isotopic “signatures.” Ancient dog bones tell us what was on the menu for both dogs and humans 2019-09-07T04:00:00Z The Russian atomic agency Rosatom said a device employing “isotopic sources of fuel on a liquid propulsion unit” was destroyed. Two victims of mysterious Russian missile blast died of radiation sickness, report says 2019-08-21T04:00:00Z The test took place on a sea platform during a period of work related to the engineering and technical support of "isotopic power sources" in a "liquid propulsion system," the agency said. Russia nuclear agency says 5 dead in missile test explosion 2019-08-10T04:00:00Z The authors demonstrate that, over this long time period, kimberlites seem to always tap a source whose isotopic composition resembles that of the primitive mantle. Enigmatic origin of diamond-bearing rocks revealed 2019-09-24T04:00:00Z This story may explain why Earth and the moon are isotopic twins because the synestia formed from the vaporized and well-mixed material derived from the two colliding bodies. When Earth and the Moon Were One 2019-07-02T04:00:00Z The isotopic record of trapped oxygen molecules therefore contains a history of ozone concentrations over the past 150 years. Ozone mystery laid to rest 2019-06-11T04:00:00Z These isotopic signatures remain stable over time, for tens of thousands of years, and provide a window into the past. Why Giant Human-Sized Beavers Died Out 10,000 Years Ago 2019-06-01T04:00:00Z He said isotopic analyses indicated the lagoon contamination is from residue from the initial nuclear weapons testing. High radiation levels found in giant clams of Marshall Islands near U.S. nuclear dump 2019-05-28T04:00:00Z For the other rock types, a near-primitive isotopic composition might be explained by the presence of recycled crust in the rock source. Enigmatic origin of diamond-bearing rocks revealed 2019-09-24T04:00:00Z "Moreover, the H-isotopic composition of the clast is suggestive of a temporal evolution of organic isotopic compositions in the comet-forming region of the disk." 3 million-year-old comet piece found inside a meteorite, could contain building blocks of life 2019-04-16T04:00:00Z The isotopic data confirmed evidence, such as company documents, that the federal investigators had already gathered. Tree sleuths are using DNA tests and machine vision to crack timber crimes 2019-04-02T04:00:00Z The isotopic signatures linked to woody plants are different from those associated with aquatic plants. Why Giant Human-Sized Beavers Died Out 10,000 Years Ago 2019-06-01T04:00:00Z Analyzing the isotopic composition of the samples will also reveal precisely how old each asteroid is, firming up the chronology of our solar system’s becoming. In Search of Life's Origins, Japan's Hayabusa 2 Spacecraft Lands on an Asteroid 2019-02-22T05:00:00Z Nisbet and his colleagues will be looking at the isotopic signature of the methane emissions contained in their samples. Tropical Africa could be a key to solving methane mystery 2019-02-05T05:00:00Z The meaning of a chemical element has changed, from Mendeleev’s concept of a stable and untransmutable substance to isotopic species that exist for only milliseconds13. Celebrate the women behind the periodic table 2019-01-27T05:00:00Z Geographical factors, such as proximity to a river, can influence the isotopic ratio. Tree sleuths are using DNA tests and machine vision to crack timber crimes 2019-04-02T04:00:00Z But in 2011, Carlson and colleagues exonerated Greenland after identifying isotopic fingerprints of its bedrock in sediment from an ocean core drilled off its southern tip. Discovery of recent Antarctic ice sheet collapse raises fears of a new global flood 2018-12-18T05:00:00Z Bones take on the isotopic signature of the place where a person was raised. Through fragments of long-lost lives, lab aims to give military families a measure of peace 2018-09-04T04:00:00Z With the isotopic signatures that Nisbet’s team will pull from their air samples from this and related field expeditions, modellers should be able to produce more-accurate estimates of global methane emissions, including in the tropics. Tropical Africa could be a key to solving methane mystery 2019-02-05T05:00:00Z About 950,000 years ago, they saw the isotopic signals shoot up, reflecting an incursion of Pacific waters, with little evidence of returning North Atlantic waters—suggesting a stark "AMOC crisis." Seafloor cores suggest sticky, thick glaciers caused mysterious shift in ice age rhythms 2018-08-22T04:00:00Z The isotopic signature was thus likely caused by the 8.2-kiloyear event, the researchers report today in the Proceedings of the National Academy of Sciences, the first direct archaeological evidence of this phenomenon. Animal fat on ancient pottery shards reveals a nearly catastrophic period of human prehistory 2018-08-13T04:00:00Z Using a technique to identify different isotopic forms of nitrogen, the authors could distinguish this ‘imported’ seabird nitrogen from locally derived nitrogen. How rats wreak havoc on coral reefs 2018-07-10T04:00:00Z On digital maps of the United States, staff members plot the hometowns of missing service members based on the isotopic signatures shared by their early-childhood geography and their bones. Through fragments of long-lost lives, lab aims to give military families a measure of peace 2018-09-04T04:00:00Z First, they used a climate model that represents isotopic tracers, which thus enabled a more direct comparison of the simulations with their measurements. A fresh take on ancient climate change in the North Pacific 2018-07-10T04:00:00Z She then analyzed the samples for their isotopic fingerprints, which provided insight into their origins. Aztec Turquoise Tiles May Solve a Mesoamerican Mystery 2018-06-13T04:00:00Z When the fragments show a shift in the isotopic ratio, that signals a change in temperature, Quinton said. The catastrophe that killed the dinosaurs created a global hothouse for 100,000 years, study says 2018-05-24T04:00:00Z This could shift the overall isotopic signature by enough to mask a rise in emissions linked to natural gas. Scientists struggle to explain a worrying rise in atmospheric methane 2018-04-26T04:00:00Z Perea commends the new study in general terms, especially as isotopic and chemical analyses of gold objects are relatively rare in Spain. Origin of Mysterious 2,700-Year-Old Gold Treasure Revealed 2018-04-10T04:00:00Z This might explain why no change in salinity was recorded in the isotopic study of foraminifera — it is thought that these organisms do not dwell at the topmost part of the ocean in this region. A fresh take on ancient climate change in the North Pacific 2018-07-10T04:00:00Z The isotopic signatures she found on the turquoise artifacts also matched the signatures of copper deposits found in Mesoamerica. Aztec Turquoise Tiles May Solve a Mesoamerican Mystery 2018-06-13T04:00:00Z Also, not mentioned in the article is that these high-sensitivity particle detectors often require extreme chemical and isotopic purity. How to Spot a Nuclear Bomb Program? Look for Ghostly Particles 2018-03-27T04:00:00Z To find out more about the remains, canine and otherwise, the team subjected 78 of the bones, each from a different skeleton, to two sorts of isotopic analysis. Dogs and cats may have been involved in Maya rituals 2018-03-21T04:00:00Z Anomalous isotopic mixtures in stellar photospheres or the interstellar medium: The Techno-Signature Challenge 2018-03-11T05:00:00Z The researchers report that isotopic analysis is about twice as sensitive as the chemical sort, able to spot adulterated shipments in which just 5% of the contents are from elsewhere. Nuclear physics and the fight against beer fraud 2018-03-08T05:00:00Z The data correlate with helium isotopic data, suggesting parallel behaviour of the isotopic systems during silicate differentiation, perhaps as early as 4.39 billion years ago. Hadean silicate differentiation preserved by anomalous 142Nd/144Nd ratios in the Réunion hotspot source 2018-02-27T05:00:00Z Sea-level and deep water temperature changes derived from benthic foraminifera isotopic records. Southern Hemisphere climate variability forced by Northern Hemisphere ice-sheet topography 2018-02-04T05:00:00Z He describes, for instance, how the isotopic signature of fish bones reveals where the fish lived, and hence whether or not the fishing was local. How fishing fed the world 2017-12-14T05:00:00Z Iron isotopic fractionation between silicate mantle and metallic core at high pressure. Hydrogen-bearing iron peroxide and the origin of ultralow-velocity zones 2017-11-21T05:00:00Z But, Young wrote, “their relative success should encourage further exploration of the potential role of collisions in determining the chemical and isotopic compositions of planets.” How Earth’s hellish birth deprived us of silver and gold 2017-09-27T04:00:00Z Preservation of Earth-forming events in the tungsten isotopic composition of modern flood basalts. Hadean silicate differentiation preserved by anomalous 142Nd/144Nd ratios in the Réunion hotspot source 2018-02-27T05:00:00Z Because the isotopic makeup of those elements varies from place to place, Diprotodon’s steadily growing teeth became, in essence, a chronicle of its movements, in layers akin to tree rings. Giant wombatlike creatures migrated across Australia 300,000 years ago 2017-09-26T04:00:00Z While most of the isotopic evidence locates these individuals’ birthplaces to North Africa, there are also written accounts of people from further south, as Dr. Nicholls notes: If Mary Beard is right, what's happened to the DNA of Africans from Roman Britain? 2017-08-09T04:00:00Z Study authors said they were able to identify the dust’s region of origin by analyzing its chemistry, geologic age and isotopic content. China's Gobi Desert feeds Yosemite National Park's forest, study says 2017-08-02T04:00:00Z Holder et al. concluded that the strikingly wide range of isotopic ratios found in the remains from the mass grave was “indicative of dietary variation associated with a multiethnic and socially stratified military population.” Food for thought: reconstructing the diet of Napoleon's Grand Army | Jennifer Raff 2017-04-18T04:00:00Z These two peaks show an isotopic pattern typical for an iron complex containing organic ligands. A low-spin Fe(iii) complex with 100-ps ligand-to-metal charge transfer photoluminescence : Nature : Nature Research 2017-03-28T04:00:00Z The selection of the top 10 ions was subject to isotopic exclusion, a dynamic exclusion window of 5.0 s, and an exclusion list of background ions based on a solvent blank. LACTB is a tumour suppressor that modulates lipid metabolism and cell state : Nature : Nature Research 2017-03-21T04:00:00Z This DNA evidence contradicts archaeological and isotopic data suggesting Neanderthals were as carnivorous as polar bears or wolves, with a diet largely based on reindeer, woolly mammoth and woolly rhinoceros. New insight into secret lives of Neanderthals - BBC News 2017-03-08T05:00:00Z This form of carbon is preferred for biological processes and is considered an isotopic signature of life. Newfound 3.77-billion-year-old fossils could be earliest evidence of life on Earth 2017-03-01T05:00:00Z Holder et al. found surprising variation in isotopic ratios among the individuals excavated from the mass grave. Food for thought: reconstructing the diet of Napoleon's Grand Army | Jennifer Raff 2017-04-18T04:00:00Z Animals that live in the sea have ratios of carbon and nitrogen isotopes that differ from those found in terrestrial animals, and this isotopic signature is passed on to the people who eat them. Why did Greenland’s Vikings disappear? 2016-11-10T05:00:00Z But, according to more recent research, based on the isotopic composition of Norse bones, the Europeans did ditch their cows. When a Country Melts 2016-10-17T04:00:00Z "Our analysis of methane’s isotopic composition clearly points to increased emissions from microbial sources, such as wetlands or agriculture." Floods and farms fuel jump in methane emissions: researchers 2016-09-27T04:00:00Z U.S. military researchers then tested the remains using dental records, DNA and isotopic analysis. Kansas Air Force pilot missing since 1965 to be buried 2016-09-11T04:00:00Z Analysing the ratios of strontium isotopes taken from sediments of known age, the pair mapped the changes in the isotopic ratio in the ocean over time. Harry Elderfield (1943-2016) : Nature : Nature Publishing Group 2016-05-17T04:00:00Z Meanwhile, an international team is analyzing the St. Helena bones using other methods, such as isotopic analysis, to discover what their shape and makeup might say about the enslaved Africans’ origins, diet, and overall health. Tracing Slaves to Their African Homelands Presented with a sample of rainwater, he could, based on its isotopic composition, determine the temperature at which the precipitation had formed. When a Country Melts 2016-10-17T04:00:00Z New lab tools bring exotic isotopic signatures into view. Rare isotopes offer clues to the chemistry of the planet | Science 2016-01-28T05:00:00Z Many abiotic processes can produce carbon with isotopic signatures similar to organic matter. Scientists may have found the earliest evidence of life on Earth 2015-10-19T04:00:00Z This isotopic curve, recorded globally in limestone, shows the shifting effects of continental weathering and hydrothermal vents. Harry Elderfield (1943-2016) : Nature : Nature Publishing Group 2016-05-17T04:00:00Z Horn Creek’s aqueous uranium isotopic ratio, like a fingerprint, links mining activity to its high uranium concentrations in water. Claims that uranium mining near the Grand Canyon is safe don't hold water | David Kreamer 2015-08-25T04:00:00Z Using a new technique that combines isotopic analysis with x-ray imaging, scientists scanned Smilodon skulls from the large collection of saber-tooth fossils at the La Brea Tar Pits in Los Angeles. Saber-tooth teeth grew at lightning speed 2015-07-01T04:00:00Z New lab tools bring exotic isotopic signatures into view. Rare isotopes offer clues to the chemistry of the planet | Science 2016-01-28T05:00:00Z For instance, the graphite could contain carbon from certain kinds of meteorites, which have the right isotopic composition. Scientists may have found the earliest evidence of life on Earth 2015-10-19T04:00:00Z But Cowan notes that the Moon’s isotopic oxygen composition is virtually identical to Earth. Earth-Moon Combination Is Likely Very Rare, Study Confirms 2015-06-27T04:00:00Z Other lines of evidence, such as surveys of carcasses and isotopic analysis of poached tusks, also suggest these areas are rife with poaching. DNA from elephant tusks reveals poaching routes 2015-06-18T04:00:00Z A 2007 computer simulation, for example, suggested that only about 1% of the large objects hitting early Earth matched its isotopic composition. How did the moon really form? 2015-04-08T04:00:00Z A large bone like the femur takes a relatively long time to renew itself completely, and its isotopic concentrations represent an average of the last 10 to 15 years of a person's life, Evans said. Richard III Really Ate and Drank Like a King 2014-08-18T04:00:00Z The crystal has a low ratio of heavy carbon atoms—called isotopes—consistent with the isotopic composition of organic matter. Scientists may have found the earliest evidence of life on Earth 2015-10-19T04:00:00Z They conclude that the chances of an impact event resulting in our own Earth-Moon system’s atomic isotopic compositions are as low as 5 to 8 percent. Earth-Moon Combination Is Likely Very Rare, Study Confirms 2015-06-27T04:00:00Z Coal from China, for instance, can be differentiated from Appalachian coal based on its isotopic signature. Desert Dust Feeds Deep Ocean Life 2014-07-16T04:00:00Z Dr Herwartz measured the difference in what is called the isotopic composition of the oxygen contained in rocks on Earth and Moon rock. Trace of another world found on Moon 2014-06-05T04:00:00Z While I was there, I continued to work on isotopic anomalies of other elements, such as chromium and barium, to trace the early stellar environment. Turning point: Liping Qin 2014-04-02T17:20:47.541Z Such reactions probably occurred near hydrothermal vents in the Hadean, van Zuilen says, and can impart isotopic signatures that are indistinguishable from biological materials. Scientists may have found the earliest evidence of life on Earth 2015-10-19T04:00:00Z The fit factor for isotopic pattern comparison was set to 80% and the expected intensity error to 3. An environmental bacterial taxon with a large and distinct metabolic repertoire 2014-02-05T18:21:56.312Z Such questions remain under active investigation, using as clues variations in isotopic distribution, or anomalies in mineral composition, that tell the story of the formation and decay of long-vanished short-lived isotopes. How Science Figured Out the Age of the Earth 2013-10-20T14:15:00.407Z If Theia had had Mars' isotopic composition, the oxygen isotopes on Earth and moon would be quite distinct. Does Mercury Hold Clues to Birth of Earth's Moon? 2013-10-17T17:15:05.127Z During that project, I found isotopic anomalies of tungsten in meteorites. Turning point: Liping Qin 2014-04-02T17:20:47.541Z The trouble is that different isotopic tracers yield wildly different dates for the most common variety of Martian meteorites, hunks of igneous rock called shergottites. Solved: The Mystery of the Martian Meteorites 2013-07-26T18:45:00.760Z Those findings differ from the isotopic makeup of the sun and the early solar system as a whole, in which lighter isotopes were more evenly represented. How Mars Lost its Atmosphere 2013-07-23T11:05:23Z Most are used to measure the elemental composition of the minerals or the isotopic makeup of those elements. Some facets of the geology of diamonds 2013-05-09T13:15:00.553Z One stumbling block of the giant impact theory of moon formation has been the incredible isotopic similarities between the Earth and the moon. Does Mercury Hold Clues to Birth of Earth's Moon? 2013-10-17T17:15:05.127Z A scientist would say, “Let me analyze the isotopic composition of its excreta and I’ll get back to you.” Scats Reveal Gorilla Diet Stats 2012-12-11T16:45:02.687Z Dr. Mannino and his colleagues did an isotopic analysis of the remains to determine what the settlers were eating. Observatory: Early Mediterranean Settlers Ate Little Seafood 2012-12-04T20:50:21Z To discern the age of these moraines, we collect rock samples from large moraine boulders and apply a relatively new isotopic method called beryllium-10 surface-exposure dating. Scientist at Work Blog: Chipping Away at the Footprints of the Past 2012-11-12T11:57:43Z Particular processes create distinctive isotopic signatures that may be preserved through a whole range of subsequent events. Some facets of the geology of diamonds 2013-05-09T13:15:00.553Z In measurements of atmospheric carbon dioxide, SAM detected a roughly 5 percent increase in heavy carbon isotopes, compared to estimated isotopic compositions at the time Mars formed. Curiosity Rover Finds No Methane on Mars--Yet 2012-11-05T19:47:47.683Z Their physical bodies are data, you can track where they've been because of the discrete isotopic characteristics of different parts of the ocean. Pacific Ocean Hacker Speaks Out 2012-10-28T20:20:26.867Z However, Rebecca McLeod says Oritain's scientists could look at the isotopic content of the water in alcohol products, analyse it and come up with a fingerprint for spirits such as whisky and vodka. Food C.S.I 2012-10-16T08:04:53Z We already knew that some tropical tree species form annual rings and we also anticipated that the isotopic signature in these rings might record changes in the climate. Tree rings show Amazon's rainfall 2012-10-02T14:05:07Z One isotopic signature only forms when ultraviolet light interacts with sulphur in an oxygen-poor environment. Some facets of the geology of diamonds 2013-05-09T13:15:00.553Z Our team is collecting rock samples from throughout the sequence that will then be taken back to the lab for isotopic analysis. Scientist at Work Blog: A 210-Million-Year-Old Puzzle 2012-09-12T10:09:34Z What complicates that story is a number of observations of "isotopic compositions" - the ratios of naturally-occurring variants of some atoms - taken from the Earth and from lunar samples. 'Hit-and-run' idea in Moon origin 2012-07-27T11:53:42Z These isotopic abundances of D and T are constrained by the fundamental laws of physics governing nuclear stability and are extremely unlikely to be different under any circumstances anywhere in the universe. Better (extraterrestrial) communication through chemistry: Isotopes and mirror-image molecules 2012-07-25T17:45:03.207Z "The isotopic values recorded in the tree rings were very closely related to annual variation in the river levels of the Amazon, and thus the amount of rainfall that flowed into the oceans." Tree rings show Amazon's rainfall 2012-10-02T14:05:07Z Scientists said this apparently confirmed the carbon isotopic evidence for woodland diets. Australopithecus Sediba Preferred Forest Foods, Fossil Teeth Suggest 2012-06-27T17:48:06Z Finkelstein’s team did an isotopic analysis of the lead in the birds and identified lead shot or bullets as the main source of contamination. California Condors Face Menace of Carcasses Laden with Bullet Lead 2012-06-26T21:15:05.007Z Earlier research also found similarities in the isotopic composition of oxygen on the Earth and the Moon. Observatory: New Insight on Moon?s Origins 2012-04-02T21:50:46Z And because simulations suggest that the second body contributed more than 40% of the Moon's bulk, the lunar isotopic ratio shouldn't mirror the terrestrial value so closely. Question Arises over Theory that Moon Resulted from Collision with Earth 2012-03-26T19:45:00.243Z If Curiosity encounters methane in the atmosphere, the rover can make isotopic analyses of the gas to help determine the methane's origin. NASA's Massive Curiosity Rover Nears Launch toward Mars 2011-11-24T12:15:05.677Z And the new isotopic result suggests that much of the released gas was methane, a far stronger greenhouse gas than carbon dioxide. Did Greenhouse Gasses Unleash the Dinosaurs? 2011-07-21T19:16:00Z Remember that a high isotopic abundance of uranium-235 is just one of four conditions required for a natural nuclear reactor to develop. Nature's Nuclear Reactors: The Two Billion Year Old Natural Fission Reactors in Gabon, Western Africa 2011-07-13T11:15:00.240Z They compared the isotopic titanium ratio in these samples to that of samples from Earth. Observatory: New Insight on Moon?s Origins 2012-04-02T21:50:46Z "The message we hope to convey is that isotopic homogeneity between the Earth and Moon is a fundamental new constraint on the evolution of the Earth-Moon system." Question Arises over Theory that Moon Resulted from Collision with Earth 2012-03-26T19:45:00.243Z While initial research was aimed at looking at seasonal variations in diet, the isotopic tests pointed them instead to apparent gender variations. Ancient cave women 'left home' 2011-06-01T17:01:39Z DeSaulty contends that because the isotopic makeup of contemporaneous coins is very consistent, the sample is likely representative of the coins that were in circulation. Conquistador Silver May Not Have Sunk Spain's Currency 2011-05-26T23:04:17Z The isotopic distribution of uranium is remarkably uniform in Earth’s crust, so all uranium ore mined today contains about 0.720% uranium-235. Nature's Nuclear Reactors: The Two Billion Year Old Natural Fission Reactors in Gabon, Western Africa 2011-07-13T11:15:00.240Z But samples of isotopic titanium from the Moon and from Earth now suggest that material from Earth is predominant on the Moon, researchers report in the journal Nature Geoscience. Observatory: New Insight on Moon?s Origins 2012-04-02T21:50:46Z But a study published today in Nature Geoscience suggests that the Moon's isotopic composition reflects only Earth's contribution. Question Arises over Theory that Moon Resulted from Collision with Earth 2012-03-26T19:45:00.243Z The net result of this is a process called isotopic fractionation. Scientist at Work: Collecting Seawater From the Depths 2011-04-04T18:37:13Z "The isotopic measurements indicate that this CAI was transported among several different nebular oxygen isotopic reservoirs, arguably as it passed through into various regions of the protoplanetary disk." Oldest Objects in Solar System Indicate a Turbulent Beginning 2011-03-07T20:00:00Z Previous Posts Evidence of Mammals and Legumes, 22 Million Years Old Our work on the Mush Valley plants and related isotopic studies will test that hypothesis. Scientist at Work: Last Look at Mush Valley 2011-01-21T16:40:10Z Petro-Find also claims that the results of its isotopic analysis represent a major shift from baseline soil carbon isotopic values for the area. Experts Criticize Evidence Used to Diagnose Leak at One of the World's Largest CO2 Storage Sites 2011-01-21T00:15:08.740Z By determining the hafnium isotopic composition and the lutetium/hafnium ratio we can determine the time at which the garnets in the rock formed. Scientist at Work: On Last Field Day, a South Pole Detour 2011-01-12T17:17:10Z So if we see preliminary isotopic evidence that a sample is older than this age threshold, we will move it on to the next step. Scientist at Work: Rocks, Zircon Zapping and a Big Shrimp 2011-01-07T21:02:35Z Correction: January 5, 2011 Due to an editing error, an earlier version of this post incorrectly described an isotopic dating process as carbon dating. Scientist at Work: Eureka! A Fossil Bone, and Water Ferns to Boot 2011-01-05T19:54:20Z Chemist Matt Hartings of American University in Washington, D.C., says that most chemists who don't think regularly about isotopic abundances or teach general chemistry at college would probably consider the atomic weights as constants. Mass Migration: Chemists Revise Atomic Weights of 10 Elements 2011-01-04T16:18:28.497Z My expertise in this work is in applying radiogenic isotopes both to determine the ages of rocks and also as isotopic fingerprints that provide clues about the origin of these rocks. Scientist at Work: For First-Timer, an Icy Challenge 2010-12-09T00:01:00Z Related News Tiny variations in the isotopic composition of silver in meteorites and Earth rocks are helping scientists put together a timetable of how our planet was assembled, beginning 4.568 billion years ago. Silver Tells a Story of Early Earth: Water Here Since Planet's Very Early Days 2010-05-17T21:44:00Z For this new phenomenon Soddy has suggested the word isotope for the element and isotopic for the property, and these names have come into general use. A Brief Account of Radio-activity The elements the box is made of are carefully averaged isotopic forms that could have come from any of nine galaxies we know about and probably more. Breaking Point |
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