|
Carbon Nanothread
A carbon nanothread (also called diamond nanothread) is a Orbital hybridisation#sp3, sp3-bonded, one-dimensional carbon crystalline nanomaterial. The tetrahedral sp3-bonding of its carbon is similar to that of diamond. Nanothreads are only a few atoms across, more than 300,000 times thinner than a Hair, human hair. They consist of a stiff, strong carbon core surrounded by hydrogen atoms. Carbon nanotubes, although also one-dimensional nanomaterials, in contrast have Orbital hybridisation#sp2, sp2-carbon bonding as is found in graphite. The smallest carbon nanothread has a diameter of only 0.2 nanometers, much smaller than the diameter of a single-wall carbon nanotube. Synthesis Nanothreads are synthesized by compressing liquid benzene to an extreme pressure of 20 GPa (around 200,000 times the air pressure at the surface of the Earth), and then slowly relieving that pressure. The mechanochemical synthesis reaction can be considered a form of Organic chemistry, organic Solid-state ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbital Hybridisation
In chemistry, orbital hybridisation (or hybridization) is the concept of mixing atomic orbitals to form new ''hybrid orbitals'' (with different energies, shapes, etc., than the component atomic orbitals) suitable for the pairing of electrons to form chemical bonds in valence bond theory. For example, in a carbon atom which forms four single bonds, the valence-shell s orbital combines with three valence-shell p orbitals to form four equivalent sp3 mixtures in a tetrahedral arrangement around the carbon to bond to four different atoms. Hybrid orbitals are useful in the explanation of molecular geometry and atomic bonding properties and are symmetrically disposed in space. Usually hybrid orbitals are formed by mixing atomic orbitals of comparable energies. History and uses Chemist Linus Pauling first developed the hybridisation theory in 1931 to explain the structure of simple molecules such as methane (CH4) using atomic orbitals. Pauling pointed out that a carbon atom forms four ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monoclinic Crystal System
In crystallography, the monoclinic crystal system is one of the seven crystal systems. A crystal system is described by three vectors. In the monoclinic system, the crystal is described by vectors of unequal lengths, as in the orthorhombic system. They form a parallelogram prism. Hence two pairs of vectors are perpendicular (meet at right angles), while the third pair makes an angle other than 90°. Bravais lattices Two monoclinic Bravais lattices exist: the primitive monoclinic and the base-centered monoclinic. For the base-centered monoclinic lattice, the primitive cell has the shape of an oblique rhombic prism;See , row mC, column Primitive, where the cell parameters are given as a1 = a2, α = β it can be constructed because the two-dimensional centered rectangular base layer can also be described with primitive rhombic axes. The length a of the primitive cell below equals \frac \sqrt of the conventional cell above. Crystal classes The table below organizes the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nature Materials
''Nature Materials'' is a monthly peer-reviewed scientific journal published by Nature Portfolio. It was launched in September 2002. Vincent Dusastre is the launching and current chief editor. Aims and scope ''Nature Materials'' is focused on all topics within the combined disciplines of ''materials science'' and ''engineering''. Topics published in the journal are presented from the view of the impact that materials research has on other scientific disciplines such as (for example) physics, chemistry, and biology. Coverage in this journal encompasses fundamental research and applications from synthesis to processing, and from structure to composition. Coverage also includes basic research and applications of properties and performance of materials. Materials are specifically described as "substances in the condensed states (liquid, solid, colloidal)", and which are "designed or manipulated for technological ends." Furthermore, ''Nature Materials'' functions as a forum for the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carnegie Institution For Science
The Carnegie Institution for Science, also known as Carnegie Science and the Carnegie Institution of Washington, is an organization established to fund and perform scientific research in the United States. This institution is headquartered in Washington, D.C. , the Institution's endowment was valued at $926.9 million. In 2018, the expenses for scientific programs and administration were $96.6 million. American astrophysicist John Mulchaey is the current president of the institution. Name More than 20 independent organizations were established through the philanthropy of Andrew Carnegie and feature his surname. In 2024, the "Carnegie Institution for Science" officially adopted the name "Carnegie Science", a name which has been used informally since 2007 when they first changed the name from "Carnegie Institution of Washington" to "Carnegie Institution for Science". History It is proposed to found in the city of Washington, an institution which ... shall in the broad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oak Ridge National Laboratory
Oak Ridge National Laboratory (ORNL) is a federally funded research and development centers, federally funded research and development center in Oak Ridge, Tennessee, United States. Founded in 1943, the laboratory is sponsored by the United States Department of Energy and administered by UT–Battelle, UT–Battelle, LLC. Established in 1943, ORNL is the largest science and energy national laboratory in the Department of Energy system by size and third largest by annual budget. It is located in the Roane County, Tennessee, Roane County section of Oak Ridge. Its scientific programs focus on materials science, materials, nuclear power, nuclear science, neutron science, energy, high-performance computing, environmental science, systems biology and national security, sometimes in partnership with the state of Tennessee, universities and other industries. ORNL has several of the world's top supercomputers, including Frontier (supercomputer), Frontier, ranked by the TOP500 as the wo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Penn State University
The Pennsylvania State University (Penn State or PSU) is a Public university, public Commonwealth System of Higher Education, state-related Land-grant university, land-grant research university with campuses and facilities throughout Pennsylvania, United States. Founded in 1855 as Farmers' High School of Pennsylvania, Penn State was named the state's first land-grant university eight years later, in 1863. Its primary campus, known as Penn State University Park, is located in State College, Pennsylvania, State College and College Township, Pennsylvania, College Township. Penn State enrolls more than 89,000 students, of which more than 74,000 are undergraduates and more than 14,000 are postgraduates. In addition to its land-grant designation, the university is a National Sea Grant College Program, sea-grant, National Space Grant College and Fellowship Program, space-grant, and one of only six Sun Grant Association, sun-grant universities. It is Carnegie Classification of Instit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Fountains Of Paradise
''The Fountains of Paradise'' is a 1979 science fiction novel by British writer Arthur C. Clarke. Set in the 22nd century, it describes the construction of a space elevator. This "orbital tower" is a giant structure rising from the ground and linking with a satellite in geostationary orbit at the height of approximately 36,000 kilometres (approx. 22,300 miles). Such a structure would be used to raise payloads to orbit without the expense of using rockets. The novel won both the Hugo and Nebula Awards for Best Novel. Plot Summary The novel focuses primarily on a project known as the Orbital Tower proposed by the main character, Vannevar Morgan. The tower is to stretch from the Earth's equator to a satellite that is in geostationary orbit. Such a structure would greatly reduce the cost of sending people and supplies into space. The main story is framed by two other stories. The first one tells of King Kalidasa, living thousands of years before Morgan is born, who is constructin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polydiacetylenes
Polydiacetylenes (PDAs) are a family of conducting polymers closely related to polyacetylene. They are created by the 1,4 topochemical polymerization of diacetylenes. They have multiple applications from the development of organic films to immobilization of other molecules. History The first polydiacetylene to be discovered was Poly(1,6-bishydroxy hexa-2,4-diacetylene) by Gerhard Wegner in 1969. This was achieved by exposing crystals of 1,6-bishydroxy hexa-2,4-diyne to UV light. Polymerization was assumed to occur because of the spatial arrangement of diynes in the crystal, but this was not confirmed until 1972 when Raymond H. Baughman coined the term "topochemical polymerization" to describe polymerization due to spatial arrangement and put forth the spatial requirements needed for a polymerization of this sort. Synthesis Synthesis of polydiacetylenes occurs through topochemical polymerization of 1,3-diynes. Typically, this must occur in the solid state, because many diynes under ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crystallite
A crystallite is a small or even microscopic crystal which forms, for example, during the cooling of many materials. Crystallites are also referred to as grains. Bacillite is a type of crystallite. It is rodlike with parallel Wikt:longulite , longulites. Structure The orientation of crystallites can be random with no preferred direction, called random Texture (chemistry), texture, or directed, possibly due to growth and processing conditions. While the structure of a single crystal is highly ordered and its crystal lattice, lattice is continuous and unbroken, amorphous solid, amorphous materials, such as glass and many polymers, are non-crystalline and do not display any structures, as their constituents are not arranged in an ordered manner. Polycrystalline structures and paracrystalline phases are in between these two extremes. Polycrystalline materials, or polycrystals, are solids that are composed of many crystallites of varying size and orientation. Most materials are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
