| 单词 | tetrahedron |
| 例句 | Once it came to rest, they deflated, and the tetrahedron unfolded to reveal the probe. The Martian 2011-01-01T00:00:00Z The hull sat on Panel A, one of four sides of the tetrahedron which brought Pathfinder to Mars. The Martian 2011-01-01T00:00:00Z With some quick and careful digging, I exposed the bulk of it, though the large tetrahedron and the deflated balloons still lurked below the surface. The Martian 2011-01-01T00:00:00Z The probe was on the central panel of the unfolded tetrahedron. The Martian 2011-01-01T00:00:00Z The lift lobby at the ME hotel, with the external wall of the tetrahedron visible. ME hotel – review 2013-03-17T00:05:33Z “There are just things happening and there are clusters of tetrahedrons moving around together.” Jim Carrey explains his bizarre Fashion Week interview, digging a deeper metaphysical hole 2017-09-12T04:00:00Z “There is no me. . . . There are clusters of tetrahedrons moving around together. . . . We don’t matter.” Perspective | What is Jim Carrey trying to tell us? 2017-11-29T05:00:00Z And, to London's treasury of remarkable if bizarre spaces, the black tetrahedron is a notable addition. ME hotel – review 2013-03-17T00:05:33Z That’s why he likes symbols so much, he said, and has them tattooed on his fingers, arms and neck: the sign of Saturn, a fire tetrahedron, a dagger-slash-cross. Lakeith Stanfield Is Playing Us All 2018-07-04T04:00:00Z The memorial’s delicate design, by the Brooklyn firm Studio ai, is reminiscent of a feather, or of a snowflake splintered into its component tetrahedrons, or of a translucent origami crane. New York’s Necessary New AIDS Memorial 2016-12-08T05:00:00Z Although he remained best known for his colored leaning planks, he also made sculptures in the shape of pyramids, ziggurats, tetrahedrons and occasionally crystals. John McCracken, Sculptor of Geometric Forms, Dies at 76 2011-04-10T23:58:44Z In Fares's latest collection, the Girl With a Pearl Earring sits prim alongside geometric tetrahedron studs and diamond rhombus rings. Why we're watching: Noor Fares 2013-07-07T06:07:04Z It’s actually a tetrahedron from which all kinds of creative characters pop forth. In ‘Also a Poet,’ a Search for Frank O’Hara and for Peace With Dad 2022-06-14T04:00:00Z For example, a tetrahedron, a solid three-dimensional pyramid with four triangular faces, would fill in a group of four neurons firing together. How Squishy Math Is Revealing Doughnuts in the Brain 2022-09-26T04:00:00Z A molecule of methane, CH4, consists of a carbon atom surrounded by four hydrogen atoms at the corners of a tetrahedron. Chemistry 2019-02-14T00:00:00Z The carbons and the four hydrogen atoms form a shape known as a tetrahedron, with four triangular faces; for this reason, methane is described as having tetrahedral geometry. Biology for AP Courses 2022-06-09T00:00:00Z Use the slicing method to derive the formula for the volume of a tetrahedron with side length a. Calculus, Volume 1 2016-03-30T00:00:00Z Off the shores of Long Beach, where sails could catch wind, a white fleet clustered around orange buoys shaped like tetrahedrons. U.S. Sailing hopes Long Beach sailing competition helps improve its Olympic results 2022-07-16T04:00:00Z Many elements overlapped, forming a multidimensional sculpture: a triangle might jut out of a tetrahedron and meet another triangle at a point. How Squishy Math Is Revealing Doughnuts in the Brain 2022-09-26T04:00:00Z For example, the nitrogen atom in ammonia is surrounded by three bonding pairs and a lone pair of electrons directed to the four corners of a tetrahedron. Chemistry 2019-02-14T00:00:00Z The simplest silicate structure, that of the mineral olivine, is composed of isolated tetrahedra bonded to iron and/or magnesium ions. Physical Geology 2015-01-01T00:00:00Z A tetrahedron with a base side of 4 units, as seen here. Calculus, Volume 1 2016-03-30T00:00:00Z Based on the silicon-oxygen tetrahedra, the crystal structure of silicates reflects the fact that silicon and oxygen are the top two of Earth’s most abundant elements. An Introduction to Geology 2017-01-01T00:00:00Z Bell and his team, called the Aerial Experiment Association, ultimately focused their kite designs on tetrahedrons, or pyramids made of four triangles, and biplane structures, several of which used red silk. Alexander Graham Bell Goes and Flies a Kite—For Science 2021-01-21T05:00:00Z The four anions surrounding this hole are arranged at the corners of a tetrahedron, so the hole is called a tetrahedral hole. Chemistry 2019-02-14T00:00:00Z The bonds in a silica tetrahedron have some of the properties of covalent bonds and some of the properties of ionic bonds. Physical Geology 2015-01-01T00:00:00Z The original design for the innovative packaging was a tetrahedron, but later the firm developed the cube-shaped cartons that are now more common. Tetra Pak billionaire Hans Rausing dies at 93 2019-08-30T04:00:00Z This silicon-oxygen tetrahedron forms bonds with many other combinations of ions to form the large group of silicate minerals. An Introduction to Geology 2017-01-01T00:00:00Z It’s a little harder to visualize than it is for the cube or tetrahedron, but it’s the same idea. A Few of My Favorite Spaces: The Pseudo-Rhombicuboctahedron 2018-03-31T04:00:00Z As a solid, as a liquid, as a gas, and in solution, white phosphorus exists as P4 molecules with four phosphorus atoms at the corners of a regular tetrahedron, as illustrated in Figure 18.24. Chemistry 2019-02-14T00:00:00Z In amphibole structures, the silica tetrahedra are linked in a double chain that has an oxygen-to- silicon ratio lower than that of pyroxene, and hence still fewer cations are necessary to balance the charge. Physical Geology 2015-01-01T00:00:00Z These are the five convex polyhedra—tetrahedron, cube, octahedron, dodecahedron, and icosahedron—that are made of congruent regular polygons. Justin Curry's Favorite Theorem 2017-12-09T05:00:00Z For example, tetrahedra can be isolated, attached in chains, sheets, or three-dimensional structures. An Introduction to Geology 2017-01-01T00:00:00Z They try to fit in, polishing their faces and sharpening their vertices, trying to sit at a lunch table with their more perfect sibling the rhombicuboctahedron or even the unwieldy truncated tetrahedron. A Few of My Favorite Spaces: The Pseudo-Rhombicuboctahedron 2018-03-31T04:00:00Z In silicon dioxide, each silicon atom links to four oxygen atoms by single bonds directed toward the corners of a regular tetrahedron, and SiO4 tetrahedra share oxygen atoms. Chemistry 2019-02-14T00:00:00Z How are the silica tetrahedra structured differently in pyroxene and amphibole? Physical Geology 2015-01-01T00:00:00Z The tetrahedron, octahedron, and icosahedron are made of four, eight, and twenty, respectively, equilateral triangles, the cube of six squares, and the dodecahedron of twelve regular pentagons. Justin Curry's Favorite Theorem 2017-12-09T05:00:00Z The crystal structure of olivine is built from independent silica tetrahedra. An Introduction to Geology 2017-01-01T00:00:00Z We are all clusters of tetrahedrons moving around together, and nothing means anything. Jim Carrey doesn’t exist – at least that’s what he told me 2017-09-26T04:00:00Z In nearly all silicates, sp3-hybridized silicon atoms occur at the centers of tetrahedra with oxygen at the corners. Chemistry 2019-02-14T00:00:00Z A silicate mineral is one in which silicon and oxygen are present as silica tetrahedra. Physical Geology 2015-01-01T00:00:00Z The cube is dual to the octahedron, the dodecahedron to the icosahedron, and the tetrahedron to itself. Justin Curry's Favorite Theorem 2017-12-09T05:00:00Z Two other similar arrangements of tetrahedra are close in structure to the neosilicates and grade toward the next group of minerals, the pyroxenes. An Introduction to Geology 2017-01-01T00:00:00Z A logical Z gate acts on the qubits along any edge of the tetrahedron. Roads towards fault-tolerant universal quantum computation : Nature : Nature Research 2017-09-12T04:00:00Z There is a variation in the silicon- to-oxygen ratio that occurs because silicon-oxygen tetrahedra may exist as discrete, independent units or may share oxygen atoms at corners in a variety of ways. Chemistry 2019-02-14T00:00:00Z The mineral quartz is made up entirely of silica tetrahedra, and some forms of quartz are known as silica. Physical Geology 2015-01-01T00:00:00Z “There is no me. There’s just things happening, and there are clusters of tetrahedrons moving around together. … It’s not our world. We don’t matter. There’s the good news.” Jim Carrey stuns reporter in bizarre red carpet interview: ‘There is no me’ 2017-09-11T04:00:00Z Members of the pyroxene family have a complex chemical composition that includes iron, magnesium, aluminum, and other elements bonded to polymerized silica tetrahedra. An Introduction to Geology 2017-01-01T00:00:00Z A logical X gate acts on the qubits on any face of the tetrahedron. Roads towards fault-tolerant universal quantum computation : Nature : Nature Research 2017-09-12T04:00:00Z Each atom within the crystal has covalent bonds to four neighboring atoms at the corners of a regular tetrahedron. Chemistry 2019-02-14T00:00:00Z The building block of all of these minerals is the silica tetrahedron, a combination of four oxygen atoms and one silicon atom. Physical Geology 2015-01-01T00:00:00Z Last month, engineers achieved first light in all four rings at the same time—a sign that the geometry of the tetrahedron is precise enough to keep all the lasers resonating properly. Buried lasers will sense Earth's spin and quakes doing the twist 2017-04-20T04:00:00Z Silicate minerals are built around a molecular ion called the silicon-oxygen tetrahedron. An Introduction to Geology 2017-01-01T00:00:00Z A logical X gate acts on the qubits on any face of the tetrahedron. Roads towards fault-tolerant universal quantum computation : Nature : Nature Research 2017-09-12T04:00:00Z The SiO4 tetrahedra in glassy silica have a random arrangement characteristic of supercooled liquids, and the glass has some very useful properties. Chemistry 2019-02-14T00:00:00Z Since the silicon ion has a charge of +4 and each of the four oxygen ions has a charge of –2, the silica tetrahedron has a net charge of –4. Physical Geology 2015-01-01T00:00:00Z The gallery’s lobby ceiling is composed of complex tetrahedron shapes, while the British museum galleries are suffused with natural light. A day in New Haven: Art, bells and of course pizza 2016-09-15T04:00:00Z A tetrahedron has a pyramid-like shape with four sides and four corners. An Introduction to Geology 2017-01-01T00:00:00Z A logical Z gate acts on the qubits along any edge of the tetrahedron. Roads towards fault-tolerant universal quantum computation : Nature : Nature Research 2017-09-12T04:00:00Z Modern tents are lighter and come in interesting shapes: tetrahedrons and domes. Like a modern madeleine, the smell of a tent brings a flood of memories 2015-10-11T04:00:00Z In olivine, unlike most other silicate minerals, the silica tetrahedra are not bonded to each other. Physical Geology 2015-01-01T00:00:00Z Now glue one triangle face of the pyramid to a triangle on the tetrahedron. Test Yourself 2014-10-08T04:00:00Z Depending on many factors, such as the original magma chemistry, silica-oxygen tetrahedra can combine with other tetrahedra in several different configurations. An Introduction to Geology 2017-01-01T00:00:00Z The colours of the faces of the tetrahedra indicate how much area exists at that given point, at a particular moment of time. Theoretical physics: The origins of space and time 2013-08-28T17:20:26.740Z This is bounded by four equilateral triangles and is identical with the regular tetrahedron of geometry. Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 7 "Crocoite" to "Cuba" 2012-01-22T03:00:24.397Z In pyroxene, silica tetrahedra are linked together in a single chain, where one oxygen ion from each tetrahedron is shared with the adjacent tetrahedron, hence there are fewer oxygens in the structure. Physical Geology 2015-01-01T00:00:00Z Perplexing Polyhedron Can you picture a solid pyramid consisting of a square base and four equilateral triangles, alongside a solid tetrahedron with four faces identical to those of the pyramid's triangles? Test Yourself 2014-10-08T04:00:00Z Imagine two pyroxene chains that connect together by sharing the third oxygen on each tetrahedron. An Introduction to Geology 2017-01-01T00:00:00Z The space-time building blocks were simple hyper-pyramids — four-dimensional counterparts to three-dimensional tetrahedrons — and the simulation's gluing rules allowed them to combine freely. Theoretical physics: The origins of space and time 2013-08-28T17:20:26.740Z In boracite there are four uniterminal triad axes, and the faces of the two tetrahedra perpendicular to them will bear opposite charges. Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 7 "Crocoite" to "Cuba" 2012-01-22T03:00:24.397Z In olivine, it takes two divalent cations to balance the –4 charge of an isolated tetrahedron. Physical Geology 2015-01-01T00:00:00Z In particular Plato tells us that they asserted that the four elements of the real world were the tetrahedron, octahedron, icosahedron, and cube, and Plutarch ascribes this doctrine to Pythagoras himself. The Teaching of Geometry 2011-10-12T02:00:52.133Z They are built with a three-dimensional framework of silica tetrahedra in which all four corner oxygens are shared with adjacent tetrahedra. An Introduction to Geology 2017-01-01T00:00:00Z It is generated by the lines which cut the faces of a tetrahedron in a constant cross ratio, and therefore by those subtending the same cross ratio at the four vertices. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 6 "Geodesy" to "Geometry" 2011-09-19T02:00:10.473Z Six of the simple forms, the cube, tetrahedron, rhombic dodecahedron, deltoid dodecahedron, triakis-tetrahedron and pentagonal dodecahedron, are geometrically the same in this class as in either the tetrahedral or pyritohedral classes. Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 7 "Crocoite" to "Cuba" 2012-01-22T03:00:24.397Z In mica structures, the silica tetrahedra are arranged in continuous sheets, where each tetrahedron shares three oxygen anions with adjacent tetrahedra. Physical Geology 2015-01-01T00:00:00Z Although Eudemus attributes all five to Pythagoras, it is certain that the tetrahedron, cube, and octahedron were known to the Egyptians, since they appear in their architectural decorations. The Teaching of Geometry 2011-10-12T02:00:52.133Z The soap film on the regular tetrahedron forms triangular surfaces on each side of the tetrahedron. Wordplay: Numberplay: Bubble Magic 2011-06-20T21:21:49Z The singular surface is made up of the faces or the vertices of the fundamental tetrahedron, and each edge of this tetrahedron is a double line of the complex. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 6 "Geodesy" to "Geometry" 2011-09-19T02:00:10.473Z Six kinds of primitive forms were distinguished, namely, the cube, the regular octahedron, the regular tetrahedron, a rhombohedron, an octahedron with a rhombic base, and a double six-sided pyramid. Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 7 "Crocoite" to "Cuba" 2012-01-22T03:00:24.397Z There is even more sharing of oxygens between adjacent tetrahedra and hence fewer charge-balancing cations are needed for sheet silicate minerals. Physical Geology 2015-01-01T00:00:00Z It is not difficult for a class to find the relative areas of the cube and the inscribed tetrahedron and octahedron. The Teaching of Geometry 2011-10-12T02:00:52.133Z It occurs crystallized in the form of the tetrahedron, also massive and disseminated. The New Gresham Encyclopedia Volume 4, Part 3: Estremoz to Felspar 2011-04-14T02:00:59.373Z Pythagorean geometry was essentially a geometry of areas and solids; its goal was the regular solids—the tetrahedron, cube, octahedron, dodecahedron and icosahedron—which symbolized the five elements of Greek cosmology. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 6 "Geodesy" to "Geometry" 2011-09-19T02:00:10.473Z My father, an engineer in the Army Corps of Engineers, was working in the concrete lab at McNary, and they did extensive tests with thousands of three-inch tetrahedrons in a model channel. 2010-01-11T23:03:00Z Silica tetrahedra are bonded in three-dimensional frameworks in both the feldspars and quartz. Physical Geology 2015-01-01T00:00:00Z Here again we may form a corresponding proposition of plane geometry by passing a plane through any three points of contact of the sphere and the tetrahedron. The Teaching of Geometry 2011-10-12T02:00:52.133Z Except here mathematicians have been thinking not about the packing of people, but of geometric solids known as tetrahedrons. 2010-01-05T21:56:00Z The regular tetrahedron, with 4 triangular faces and 4 vertices; 2. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 6 "Geodesy" to "Geometry" 2011-09-19T02:00:10.473Z After concluding that the idea would work, they fabricated 3,280 concrete tetrahedrons weighing 12 tons each near the dam site and dropped them into the channel from a cableway. 2010-01-11T23:03:00Z In addition to silica tetrahedra, feldspars include the cations aluminum, potassium, sodium, and calcium in various combinations. Physical Geology 2015-01-01T00:00:00Z The figure is difficult to draw, but it is not difficult to understand, particularly if we construct the tetrahedron out of pasteboard. The Teaching of Geometry 2011-10-12T02:00:52.133Z A tetrahedron is a simple construct — four sides, each a triangle. 2010-01-05T21:56:00Z These give the solid angles of the tetrahedron, the octahedron and the icosahedron. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 6 "Geodesy" to "Geometry" 2011-09-19T02:00:10.473Z Penetration twins with a tetrahedron face as twin-plane are sometimes observed. Encyclopaedia Britannica, 11th Edition, Volume 4, Slice 2 "Bohemia" to "Borgia, Francis" The hardness and lack of cleavage in quartz result from the strong covalent/ionic bonds characteristic of the silica tetrahedron. Physical Geology 2015-01-01T00:00:00Z A sphere may be circumscribed about any given tetrahedron. The Teaching of Geometry 2011-10-12T02:00:52.133Z For the packing problem, researchers are looking at so-called regular tetrahedrons, where each side is an identical equilateral triangle. 2010-01-05T21:56:00Z In this case each figure forms a tetrahedron. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 6 "Geodesy" to "Geometry" 2011-09-19T02:00:10.473Z Beautiful isolated tetrahedra of transparent yellow blende are found in the snow-white crystalline dolomite of the Binnenthal in the Valais, Switzerland. Encyclopaedia Britannica, 11th Edition, Volume 4, Slice 1 "Bisharin" to "Bohea" The smallest particles of fire are tetrahedra, of air octahedra, of water icosahedra. A Critical History of Greek Philosophy A sphere may be inscribed in any given tetrahedron. The Teaching of Geometry 2011-10-12T02:00:52.133Z Aristotle mistakenly thought that identical regular tetrahedrons packed together perfectly, as identical cubes do, leaving no gaps in between and filling 100 percent of the available space. 2010-01-05T21:56:00Z If six films of the same liquid meet in a point the corresponding tetrahedron is a regular tetrahedron, and each film, where it meets the others, has an angle whose cosine is −1⁄3. Encyclopaedia Britannica, 11th Edition, Volume 5, Slice 3 "Capefigue" to "Carneades" The crystals are minute tetrahedrons, with each pointed corner an electrical contact. Check and Checkmate That matter whose smallest particles are regular tetrahedra, said Philolaus, is fire. A Critical History of Greek Philosophy If the grooves be left out of account, the large faces which have replaced each tetrahedron corner then make up a figure which has the aspect of a simple octahedron. Encyclopaedia Britannica, 11th Edition, Volume 8, Slice 4 "Diameter" to "Dinarchus" Even after that, the packing of tetrahedrons garnered little interest. 2010-01-05T21:56:00Z Arrangements connected with Claus’ formula are obtained by placing six tetrahedra on the six triangles formed by the diagonals of a plane hexagon. Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 1 "Châtelet" to "Chicago" Atoms combine to form molecules, and molecules arrange themselves in certain definite geometric forms such as cubes, tetrahedra, hexagonal prisms and stellate forms, with properties emphasized on certain faces or ends. The Machinery of the Universe Mechanical Conceptions of Physical Phenomena About Mars’ orbit describe a tetrahedron; the sphere containing this will be Jupiter’s orbit. The Astronomy of Milton's 'Paradise Lost' Unaware that the spherical arrangement had been used years before, I devised a double tetrahedron to classify colors, while a student of painting in 1879. A Color Notation A measured color system, based on the three qualities Hue, Value and Chroma With tetrahedrons, the best packing arrangement is not obvious, and after it was pointed out that tetrahedrons did not pack perfectly, it seemed that they did not pack very well at all. 2010-01-05T21:56:00Z Two parallel triangular faces are removed from a cardboard model of a regular octahedron, and on the remaining six faces tetrahedra are then placed; the hydrogen atoms are at the free angles. Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 1 "Châtelet" to "Chicago" Round Mars describe a tetrahedron; the circle including this will be Jupiter. The Martyrs of Science, or, The lives of Galileo, Tycho Brahe, and Kepler The effect was as though one were looking down at the apex of a regular tetrahedron. Islands of Space If the two carbon atoms unite by the ethylene kind of union, the union will be along a line corresponding to one of the edges of each tetrahedron. Scientific American Supplement, No. 633, February 18, 1888 The Princeton paper also led Jeffrey C. Lagarias, a mathematics professor at the University of Michigan, to ask Elizabeth Chen, one of his graduate students, to look at tetrahedron packing. 2010-01-05T21:56:00Z Assuming the four valencies of the carbon atom to be directed from the centre of a regular tetrahedron towards its four corners, the angle at which they meet is 109� 28′. Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 1 "Châtelet" to "Chicago" I possess a tetrahedron, or triangular pyramid, formed of six sticks glued together, as shown in the illustration. Amusements in Mathematics There were characters in Nansalese at each point of the tetrahedron, and other characters engraved in a circle around it. Islands of Space By following the change on the model, it is seen that in the resulting figure the two chlorine atoms in ethylene chloride are situated at angles of the two tetrahedrons which are nearest each other. Scientific American Supplement, No. 633, February 18, 1888 After making physical models of tetrahedrons and demonstrating the packing patterns, she convinced Dr. Lagarias that her packings were as dense as she had said they were, and finally published her findings a year ago. 2010-01-05T21:56:00Z We may therefore regard the nitrogen atoms as occupying the centres of a cubic space lattice composed of iodine atoms, between which the hydrogen atoms are distributed on the tetrahedron face normals. Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 1 "Châtelet" to "Chicago" This puzzle concerns the painting of the four sides of a tetrahedron, or triangular pyramid. Amusements in Mathematics The tetrahedron you have chosen; so let it be. Islands of Space This involves a partial revolution of the two tetrahedrons in opposite directions around their common axis. Scientific American Supplement, No. 633, February 18, 1888 Meanwhile, Sharon C. Glotzer, a professor of chemical engineering also at the University of Michigan, was interested to see whether the tetrahedrons might line up as liquid crystals do. 2010-01-05T21:56:00Z To make, out of cardboard, a tetrahedron like one given to him, is a problem which will interest the pupil and serve as a convenient starting-point. Essays on Education and Kindred Subjects Everyman's Library It will be seen that the tetrahedron is the fundamental form, the three-sided pyramid on a triangular base, i.e., a solid figure formed from four triangles. Occult Chemistry Clairvoyant Observations on the Chemical Elements It will be noted that these are the two dimensional correlatives of the sphere, the tetrahedron and the cube, mentioned as being among the determining forms in molecular structure. The Beautiful Necessity Seven Essays on Theosophy and Architecture Suppose, for example, that we attempt to deal decoratively which such simple figures as the three lowest Platonic solids—the tetrahedron, the hexahedron, and the octahedron. Architecture and Democracy Dr. Glotzer and her colleagues wrote a computer program that simulated the jostling of tetrahedrons and how they arranged themselves when pushed together. 2010-01-05T21:56:00Z Round Mars describe a tetrahedron; the sphere including this will be Jupiter. Kepler The tetrahedron is the form of chromium and molybdenum, but not that of the head of their group, oxygen, which is, like hydrogen, sui generis. Occult Chemistry Clairvoyant Observations on the Chemical Elements Platonic bodies; cube, rhomboid; tetrahedron, pentahedron, hexahedron, octahedron, dodecahedron, icosahedron, eicosahedron; prism, pyramid; parallelopiped; curb roof, gambrel roof, mansard roof. Roget's Thesaurus of English Words and Phrases This regular solid of four-dimensional space consists of sixteen cells, each a regular tetrahedron, thirty-two triangular faces, twenty-four edges and eight vertices. Architecture and Democracy But while Dr. Glotzer’s structure was surprisingly complex — the repeat pattern consists of 82 tetrahedrons — the Cornell crystal was surprisingly simple, with just four. 2010-01-05T21:56:00Z Almost touching them with their bases were an equal number of pyramids, of tetrahedrons, as sharply angled and of similar length. The Metal Monster It should be noted that it is not possible to show five of the prisms in the five intersecting tetrahedra of prisms, and 30 atoms must, therefore, be added in counting. Occult Chemistry Clairvoyant Observations on the Chemical Elements Today, no less than in the past, the tetrahedral form of the earth and the relation of the tetrahedron to the poles and to the equator preserve the conditions that favor rapid evolution. The Red Man's Continent: a chronicle of aboriginal America The globe, e, is a new form, the four tetrahedra of the proto level making a single twelve-atomed one on the meta. Occult Chemistry Clairvoyant Observations on the Chemical Elements It is also puzzling to researchers why the tetrahedrons in Dr. Glotzer’s simulations tend to the complex quasicrystal structures if the best packing is actually a much simpler structure. 2010-01-05T21:56:00Z Its head was a pyramid, a tetrahedron; its length vanished in the further darkness. The Metal Monster Above the tetrahedron is a balloon-shaped figure, apparently drawn into shape by the attraction of the tetrahedron. Occult Chemistry Clairvoyant Observations on the Chemical Elements Each of the four depressed areas forms a side of our tetrahedron and is occupied by an ocean. The Red Man's Continent: a chronicle of aboriginal America The Tetrahedron.—The characteristics of this form are four funnels, containing ovoid bodies, opening on the face of a tetrahedron. Occult Chemistry Clairvoyant Observations on the Chemical Elements The new world record for packing density of tetrahedrons: 85.63 percent. 2010-01-05T21:56:00Z From the sides of the hollow square sprang long arms of spheres, each tipped by a tetrahedron. The Metal Monster As a proto-element it becomes three triangles, joined at their apices, in fact a tetrahedron in which no atoms are distributed on the fourth face. Occult Chemistry Clairvoyant Observations on the Chemical Elements The tetrahedron is not confined to the external form of the above atoms; it seems to be one of the favourite forms of nature, and repeatedly appears in the internal arrangements. Occult Chemistry Clairvoyant Observations on the Chemical Elements It is worthy of notice that in diatomic elements four funnels open on the faces of tetrahedra; in triatomic, six funnels on the faces of cubes; in tetratomic, eight funnels on the faces of octahedra. Occult Chemistry Clairvoyant Observations on the Chemical Elements Molybdenum presents us with only two new forms, and these are merely four-atomed tetrahedra, occurring in pairs as object and image. Occult Chemistry Clairvoyant Observations on the Chemical Elements Between these fissures the Metal Things that made up each now dissociate and shapeless mass geysered; block and sphere and tetrahedron spike spun and swirled. The Metal Monster The "cigar" tetrahedron of d follows its course as in occultum, and the other sets free two quartets and two triplets on the meta level, yielding six duads and two units as hyper compounds. Occult Chemistry Clairvoyant Observations on the Chemical Elements We have, therefore, only to consider the spikes, pointing to the angles of the enclosing tetrahedron, and the central globe. Occult Chemistry Clairvoyant Observations on the Chemical Elements On the meta level five of the nine atoms hold together and place themselves on the angles of a square-based pyramid; the remaining four set themselves on the angle of a tetrahedron. Occult Chemistry Clairvoyant Observations on the Chemical Elements The two groups are not closely allied in composition, though both titanium and tin have in common the five intersecting tetrahedra at their respective centres. Occult Chemistry Clairvoyant Observations on the Chemical Elements We passed, silently; behind us she came, followed by three of the great globes, by a pair of her tetrahedrons. The Metal Monster In the tetrahedron four funnels are found, the mouth of each funnel opening on one of its faces. Occult Chemistry Clairvoyant Observations on the Chemical Elements The atoms are arranged in two tetrahedra with a common apex, and the relationship is maintained in the meta-body, a septet. Occult Chemistry Clairvoyant Observations on the Chemical Elements In this case the funnels radiate from a central globe, formed of two intersecting tetrahedra, with "cigars" at each point enclosing a four-atomed globe. Occult Chemistry Clairvoyant Observations on the Chemical Elements We here meet the tetrahedron for the first time, with each angle occupied by a six-atomed group, the atoms arranged as on the end triangles of a prism. Occult Chemistry Clairvoyant Observations on the Chemical Elements Now to check them soared from the ranks of the besiegers clouds of countless horned dragons, immense cylinders of clustered cubes studded with the clinging tetrahedrons. The Metal Monster B is the same as the right-hand funnel of gallium, except that its lowest body consists of two square-based pyramids and a tetrahedron. Occult Chemistry Clairvoyant Observations on the Chemical Elements They separated, lining up on each side of the leader now standing a little in advance of the twin tetrahedrons, rigid and motionless as watching guards. The Metal Monster |
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