showing diamine molecules (containing blue nitrogen atoms) attached to metal (manganese) atoms (green). Carbon dioxide molecules (grey carbon atoms with two red oxygen atoms) bind through a cooperative mechanism akin to a chain reaction along the pore surfaces.
Some H atoms (white) are omitted for clarity. Graphic by Thomas Mcdonald, Jarad Mason, Jeffrey Long/UC Berkeley) Though power plants are required not now to capture carbon dioxide from their emissions,
it will eventually be necessary in order to slow the pace of climate change caused by fossil-fuel burning.
"Long's team found that the diamines bind to the metal atoms of the MOF
meaning the atom-by-atom modifications that researchers need to optimize these molecules into therapeutic compounds
But quantum phenomena are only observable in the smallest of objects, such as atoms or molecules,
"Tiny objects like atoms behave according to the laws of quantum physics, "says James Millen (UCL Physics
The largest objects that have been made to behave in a quantum manner are large molecules of about 800 atoms.
We are trying to do the same with glass particles made up of billions of atoms,
when atoms stop vibrating. Widely-used technologies, such as laser cooling, that work for atoms won't work for such large objects,
and a related technique called cavity cooling must be used. During cavity cooling, a particle is suspended by a laser light field contained between two mirrors,
Now, a team of experimentalists led by the Department of energy's Oak ridge National Laboratory has demonstrated an energy-efficient desalination technology that uses a porous membrane made of strong, slim graphene--a carbon honeycomb one atom thick.
"Graphene to the rescue Graphene is only one-atom thick, yet flexible and strong. Its mechanical and chemical stabilities make it promising in membranes for separations.
The chemical vapor deposited carbon atoms that self-assembled into adjoining hexagons to form a sheet one atom thick.
, positively charged sodium atoms and negatively charged chloride atoms. To figure out the best pore size for desalination,
allowed for atom-resolution imaging of graphene, which the scientists used to correlate the porosity of the graphene membrane with transport properties.
In contrast, charged atoms, called ions, have an excellent memory: They can store quantum information for many minutes.
when a nitrogen atom substitutes for a carbon atom and is adjacent to a vacancy, or missing carbon atom, in the lattice.
In polycrystalline samples, atoms are arranged not in a regular repeating lattice over long distances, thus electrons travel dont travel very far--roughly 10 nanometers or less--before scattering off an obstacle.
and charged atoms (ions) play a key role in the temperature sensitivity of both living plant cells and the dry cyberwood.
Phonons typically move in straight lines in nanowires threads barely a few atoms wide. Previous calculations suggested that if parts of a nanowire contained random arrangements of two different types of atoms,
phonons would be stopped in their tracks. In actual alloy nanowires though, atoms of the same element might cluster together to form short sections composed of the same elements.
Now, Zhun-Yong Ong and Gang Zhang of the A*STAR Institute Of high Performance Computing in Singapore have calculated the effects of such short-range order on the behavior of phonons("Enhancement and reduction of one-dimensional
"Their results suggest that heat conduction in a nanowire does not just depend on the relative concentrations of the alloy atoms and the difference in their masses;
it also depends on how the atoms are distributed. Their model simulated an 88-micrometer-long nanowire containing 160,000 atoms of two different elements.
They found that when the nanowire was ordered more containing clusters of the same elements low-frequency phonons struggled to Move in contrast,
The researchers used their model to study the thermal resistance of a nanowire containing an equal mix of silicon and germanium atoms.
Short-range ordering of the atoms allowed high-frequency phonons to travel freely through the wire giving it a relatively low thermal resistance.
In contrast, a random distribution of alloy atoms resulted in a higher resistance over triple that of the ordered case for a 2. 5-micrometer-long wire.
"This is an electron wave in a phosphorus atom, distorted by a local electric field. Unlike conventional computers that store data on transistors and hard drives, quantum computers encode data in the quantum states of microscopic objects called qubits.
& Communication Technology, was first in the world to demonstrate single-atom spin qubits in silicon,
like the spin of a single phosphorus atom in isotopically enriched silicon, can be controlled using electric fields,
Associate professor Morello said the method works by distorting the shape of the electron cloud attached to the atom,
Here, the'knob'is applied the voltage to a small electrode placed above the atom.""The findings suggest that it would be possible to locally control individual qubits with electric fields in a large-scale quantum computer using only inexpensive voltage generators, rather than the expensive high-frequency microwave sources.
which contain a central metal atom bound to several nitrogen-containing rings. Hemoglobin, which carries oxygen in the blood,
is a metalloporphyrin with iron as the central atom. For this sensor, the researchers used a metalloporphyrin with cobalt at its center.
The scientists coat gold nanoparticles of a few thousand atoms each with an oil-like organic molecule that holds the gold particles together.
or about six atoms thick, is so tiny it would not normally be measurable. Subramanian Sankaranarayanan and Sanket Deshmukh at CNM used the high-performance computing resources at DOES National Energy Research Scientific Computing Center and the Argonne Leadership Computing Facility (ALCF), both
With their aligned atoms, the graphene-nanotube digital switches could avoid the issues of electron scattering. ou want to control the direction of the electrons,
Its molecular structure is an atomic sandwich made up of one molybdenum atom for every two tellurium atoms HY1.
These atoms form a thin, molecular sandwich with the one metal and two chalcogenides, and depending on their fabrication method can exist in several slightly different shaped atomic arrangements.
As the chips approach single or several atom thickness, (commonly referred to as 2-dimensional),
which was several atoms thick. They directed a 1 m wide laser (a human hair is 17 to 181 m) at the 2h-Mote2
It consists of small clusters of four copper atoms each, supported on a thin film of aluminum oxide.
which limits how many atoms can catch and hold carbon dioxide.""With our catalyst, there is no inside,
"All four copper atoms are participating because with only a few of them in the cluster,
A defect-free layer is also impermeable to all atoms and molecules. This amalgamation makes it a terrifically attractive material to apply to scientific developments in a wide variety of fields, such as electronics, aerospace and sports.
Each new combination of atom-thick layers presents new properties and researchers suspect that one, or more, of these new materials will exhibit energy storage
the researchers selectively extract layers of aluminum atoms from a block of MAX phase by etching them out with an acid."
where the titanium atoms are in center and the molybdenum on the outside. The next Frontier Now, with the help of theoretical calculations done by researchers at the FIRST ENERGY Frontier Research center at the Oak ridge National Laboratory,
"Carbon nanotubes are rolled-up arrays of perfect hexagons of atoms; graphene is a rolled out sheet of the same.
the way the atoms are arranged can influence all those properties. ome labs are actively trying to make these materials or measure properties like the strength of single nanotubes and graphene sheets,
or lose atoms to neighboring rings, depending on how they join with their neighbors. By forcing five, seven or even eight-atom rings
they found they could gain a measure of control over the hybrid mechanical properties. Turning the nanotubes in a way that forced wrinkles in the graphene sheets added further flexibility and shear compliance,
with their atoms arranged in a highly organised and regular manner. Metallic glass alloys, however, have disordered a highly structure,
with the atoms arranged in a non-regular way.""There are many types of metallic glass, with the most popular ones based on zirconium, palladium, magnesium, titanium or copper.
Current transistors consist of only a handful of atoms. It is a major challenge to produce chips in
#Physicists determine the three-dimensional positions of individual atoms for the first time Atoms are the building blocks of all matter On earth,
Now, scientists at UCLA have used a powerful microscope to image the three-dimensional positions of individual atoms to a precision of 19 trillionths of a meter,
to infer the macroscopic properties of materials based on their structural arrangements of atoms, which will guide how scientists and engineers build aircraft components, for example.
a UCLA professor of physics and astronomy and a member of UCLA California Nanosystems Institute, is published Sept. 21 in the online edition of the journal Nature Materials("Three-dimensional coordinates of individual atoms
"For more than 100 years, researchers have inferred how atoms are arranged in three-dimensional space using a technique called X-ray crystallography,
However, X-ray crystallography only yields information about the average positions of many billions of atoms in the crystal,
Because X-ray crystallography doesn reveal the structure of a material on a per-atom basis
the technique can identify tiny imperfections in materials such as the absence of a single atom.
and measures how many electrons interact with the atoms at each scan position. The method reveals the atomic structure of materials
because different arrangements of atoms cause electrons to interact in different ways. However scanning transmission electron microscopes only produce two-dimensional images.
the researchers were able to slowly assemble a 3-D model of 3, 769 atoms in the tip of the tungsten sample.
Miao and his team showed that the atoms in the tip of the tungsten sample were arranged in nine layers, the sixth
The researchers believe the defect was either a hole in an otherwise filled layer of atoms
or one or more interloping atoms of a lighter element such as carbon. Regardless of the nature of the point defect, the researchersability to detect its presence is significant,
demonstrating for the first time that the coordinates of individual atoms and point defects can be recorded in three dimensions. e made a big breakthrough,
Miao and his team plan to build on their results by studying how atoms are arranged in materials that possess magnetism or energy storage functions,
Phase change materials that change their optical properties depending on the arrangement of the atoms allow for the storage of several bits in a single cell.
novel materials that change their optical properties depending on the arrangement of the atoms: Within shortest periods of time, they can change between crystalline (regular) and amorphous (irregular) states.
i e. depending on the arrangement of the atoms in the material. This changeability between crystalline (regular) and amorphous (irregular) states allowed the team to store many bits in a single integrated nanoscale optical phase-change cell l
when atoms are brought too close together-to detect a wide array of protein markers that are linked to various diseases.
From spontaneous emission of light by excited atoms e g. in a fluorescent tube to influences on the structure of the universe during the Big Bang:
A sheet of graphene is an ultrathin lattice of carbon atoms that is one atom thick, so pores in graphene are defined at the atomic scale.
which given the single-atom thickness of graphene makes them among the smallest pores through
it is due to the canting between the atomic magnets from one atom to the next (see figure.
the scientists set out to learn its atom-resolution structure. This involved feedback between experiment and theory.
NMR measures a trait known as chemical shift for some of the individual atoms in the sample,
which can reveal how those atoms are connected. ou look at changes in chemical shift and that tells you, for example,
and can be reduced to almost the size of atoms. The scientists achieve a long storage time by setting the ion density in the cells precisely via the voltage applied."
Graphene is an incredibly strong one-atom-thick layer of carbon, and is known for its excellent conductive properties of heat and electricity.
Chemical reactions and material phase transitions, for example, happen on the scale of atoms --which are about one tenth of one billionth of a meter across--and attoseconds
When the pulses hit the atoms in a material, the electrons scatter like a wave.
scientists can determine information like the distance between atoms. Conventional electron pulse technology uses a static magnetic field to compress the electrons transversely.
the proposed scheme is potentially useful for focusing other particles such as accelerated protons and neutral atoms.
and this method provides a straightforward way to make semiconducting nanoscale circuits from graphene, a form of carbon only one atom thick.
"Graphene, a one-atom-thick, two-dimensional sheet of carbon atoms, is known for moving electrons at lightning speed across its surface without interference.
where single atoms connect to each other in a diamond-like grid structure, each face of a crystal (1, 1,
#Scientists design a full-scale architecture for a quantum computer in silicon Australian scientists have designed a 3d silicon chip architecture based on single atom quantum bits,
and have developed the world's most efficient quantum bits in silicon using either the electron or nuclear spins of single phosphorus atoms.
#Ultrasensitive sensors made from boron-doped graphene Ultrasensitive gas sensors based on the infusion of boron atoms into graphene--a tightly bound matrix of carbon atoms--may soon be possible, according to an international team of researchers
With the addition of boron atoms, the boron graphene sensors were able to detect noxious gas molecules at extremely low concentrations, parts per billion in the case of nitrogen oxides and parts per million for ammonia
"We were previously able to dope graphene with atoms of nitrogen, but boron proved to be much more difficult.
confirmed the presence of the boron atoms in the graphene lattice and their effect when interacting with ammonia or nitrogen oxide molecules.
Phase-change materials that change their optical properties depending on the arrangement of their constituent atoms allow for the storage of several bits in a single cell.
which are novel materials that change their optical properties depending on the arrangement of the atoms.
and this method provides a straightforward way to make semiconducting nanoscale circuits from graphene, a form of carbon only one atom thick.
"Graphene, a one-atom-thick, 2-D sheet of carbon atoms, is known for moving electrons at lightning speed across its surface without interference.
where single atoms connect to each other in a diamond-like grid structure, each face of a crystal (1, 1,
and be transferred to a different atom or molecule. Ultimately, it is these electrons which are transferred to the protons in the water moleculend thereby create elementary hydrogen.
#Cobalt atoms on graphene a powerful combo Graphene doped with nitrogen and augmented with cobalt atoms has proven to be an effective, durable catalyst for the production of hydrogen from water, according to scientists at Rice Univ. The Rice lab of chemist James Tour and colleagues at the Chinese Academy of Sciences,
the Univ. of Texas at San antonio and the Univ. of Houston have reported the development of a robust,
Catalysts can split water into its constituent hydrogen and oxygen atoms, a process required for fuel cells.
but the use of atoms, Tour said. he particles doing this chemistry are as small as you can possibly Get even particles on the nanoscale work only at the surface,
he said. here are so many atoms inside the nanoparticle that never do anything. But in our process the atoms driving catalysis have no metal atoms next to them.
Wee getting away with very little cobalt to make a catalyst that nearly matches the best platinum catalysts.
Tour said single-atom catalysts have been realized in liquids, but rarely on a surface. his way we can build electrodes out of it,
The researchers discovered that heat-treating graphene oxide and small amounts of cobalt salts in a gaseous environment forced individual cobalt atoms to bind to the material.
Electron microscope images showed cobalt atoms widely dispersed throughout the samples. They tested nitrogen-doped graphene on its own and found it lacked the ability to kick the catalytic process into gear.
Atom-thick graphene is the ideal substrate, Tour said, because of its high surface area, stability in harsh operating conditions and high conductivity.
and iron atoms dispersed throughout the structure, with links of benzenedipyrazolate (bdp). Both cobalt (bdp) and iron (bdp) are highly porous when expanded,
and arsenic atoms that can capture electrons on a 2-D plane. Only a few groups in the world are able to grow the material,
'fluffy'carbon electrode made from graphene (comprising one-atom-thick sheets of carbon atoms), and additives that alter the chemical reactions at work in the battery,
while flowing nitrogen gas is known to extract oxygen atoms from the bismuth vanadate, creating"defects."
which means their atoms are arranged in a highly organised way. Metallic glass alloys, on the other hand, have disordered a highly structure,
with their atoms arranged irregularly. The new model, which is described in Nature Communications, looks at the atomic structure of different metals and identifies
was first in the world to demonstrate single-atom spin qubits in silicon, reported in Nature in 2012 and 2013.
like the spin of a single phosphorus atom in isotopically enriched silicon, can be controlled using electric fields,
Associate professor Morello said the method works by distorting the shape of the electron cloud attached to the atom,
Here, the'knob'is applied the voltage to a small electrode placed above the atom.""The findings suggest that it would be possible to locally control individual qubits with electric fields in a large-scale quantum computer using only inexpensive voltage generators, rather than the expensive high-frequency microwave sources.
A leading proposal suggested that KP1212 derived its mutagenicity by shape shifting--converting into a different molecular structure by repositioning its hydrogen atoms on nitrogen and oxygen atoms.
The work taught his team how to create even more potent shape shifters--by decorating the KP1212 scaffold with groups of atoms and molecules that further raises their ability to capture protons."
which an otherwise strong bond between individual atoms dissolves in one location --and forms again precisely when energy is pumped into the structure.
"We developed a nanotechnology at the HZDR that relies on extremely thin tips made of very few gold atoms.
Insulators typically become metallic by a reduction in the spacing between atoms in the material.
electrons localize between the atoms and do not freely flow as they do in the metallic form."
Zeng and his colleagues unveiled the arrangements for a molecule featuring 68 gold atoms and 32 pairs of bonded sulfur-hydrogen atoms.
Sixteen of the gold atoms form the molecule's core; the remainder bond with the sulfur
-and-protect"to configure potential arrangements of the remaining gold atoms and sulfur-hydrogen pairs surrounding the core.
medium and long staple--such as the fact that a short staple consists of two sulfur atoms bonded with one gold.
By combining this information with their knowledge of how many atoms reside outside the core the team reduced the number of potential arrangements from millions to mere hundreds."
#Chemists cook up three atom-thick electronic sheets This process of film deposition is common for traditional semiconductors like silicon
when it is just atoms thick. Three atom-thick layers of molybdenum disulfide were cooked up in the lab of Jiwoong Park, associate professor of chemistry and chemical biology and member of the Kavli Institute at Cornell for Nanoscale Science.
The films were designed and grown by postdoctoral associate Kibum Kang and graduate student Saien Xie. Their work is published online in Nature, April 30."
but with different materials, it starts with a powdery precursor, forms a gas and sprinkles single atoms onto a substrate, one layer at a time.
This effectively proved that these three-atom-thick semiconducting films can be made into multilevel electronic devices of unsurpassed thinness.
The paper is titled"High-mobility three-atom-thick semiconducting films with wafer scale homogeneity.""The work was supported by the Air force Office of Scientific research,
"Traditional drugs--from cold medicine to chemotherapy--are composed of small molecules of a few dozen atoms, typically.
"Native defects, a type of structural flaw in which the regular pattern of atoms is altered naturally during crystal growth, play an important role in charge carrier trapping and recombination in semiconductors.
so that a carbon atom from the diamond lattice was replaced with a nitrogen atom in their crystal lattices with a missing atom directly adjacent.
We're able to see how atoms in molecules move with UED, which is an important step toward making molecular movies of ultrafast chemical reactions."
These atoms form a thin, molecular sandwich with the one metal and two chalcogenides, and depending on their fabrication method can exist in several slightly different shaped atomic arrangements.
As the chips approach single or several atom thickness, (commonly referred to as 2-dimensional),
which was several atoms thick. They directed a 1 m wide laser (a human hair is 17 to 181 m) at the 2h-Mote2
#Scientists determine how antibiotic gains cancer-killing sulfur atoms In a discovery with implications for future drug design,
"Until our study, we didn't really know how sulfur atoms are incorporated into a natural product--now we have discovered a new family of enzymes
it is particularly exciting that this new discovery now provides the possibilities of adding sulfur atoms to compounds similar to leinamycin or other polyketide natural products."
Each new combination of atom-thick layers presents new properties and researchers suspect that one, or more, of these new materials will exhibit energy storage
the researchers selectively extract layers of aluminum atoms from a block of MAX phase by etching them out with an acid."
where the titanium atoms are in center and the molybdenum on the outside. The next Frontier Now, with the help of theoretical calculations done by researchers at the FIRST ENERGY Frontier Research center at the Oak ridge National Laboratory,
The researcher explains that"ozone is composed triatomic (molecule of three atoms) oxygen which is very reactive
This involves exciting a single atom with just a tiny amount of light. The theory states that the light scattered by this atom should,
similarly, be squeezed. Unfortunately, although the mathematical basis for this method--known as squeezing of resonance fluorescence--was drawn up in 1981,
or photons, using an artificially constructed atom, known as a semiconductor quantum dot. Thanks to the enhanced optical properties of this system and the technique used to make the measurements,
because we now have artificial atoms with optical properties that are superior to natural atoms.
In the Cambridge experiment, the researchers achieved this by shining a faint laser beam on to their artificial atom, the quantum dot.
A quantum dot is a collection of a few hundred thousand atoms that can form itself into a semiconductor under certain conditions.
Richard J. Warburton from the University of Basel have shown already in past publications that the indistinguishability of the photons is reduced by the fluctuating nuclear spin of the quantum dot atoms.
University of British columbia (UBC) physicists have been able to create the first ever superconducting graphene sample by coating it with lithium atoms.
Although superconductivity has already been observed in intercalated bulk graphite--three-dimensional crystals layered with alkali metal atoms,
"Decorating monolayer graphene with a layer of lithium atoms enhances the graphene's electron-phonon coupling to the point where superconductivity can be induced,
"Decorating monolayer graphene with a layer of lithium atoms enhances the graphene's electron-phonon coupling to the point where superconductivity can be stabilized."
University of British columbia (UBC) physicists have been able to create the first ever superconducting graphene sample by coating it with lithium atoms.
Although superconductivity has already been observed in intercalated bulk graphite--three-dimensional crystals layered with alkali metal atoms,
"Decorating monolayer graphene with a layer of lithium atoms enhances the graphene's electron-phonon coupling to the point where superconductivity can be induced,
"Decorating monolayer graphene with a layer of lithium atoms enhances the graphene's electron-phonon coupling to the point where superconductivity can be stabilized."
electrically atoms. They direct a broad beam of noble gas ions onto a gallium arsenide wafer, which,
not only shift the atoms they hit, but also knock individual atoms entirely out of the crystal structure.
Since the volatile arsenic does not remain bound on the surface, the surface soon consists only of gallium atoms.
In order to compensate for the missing arsenic atom bonds, pairs of two gallium atoms form, which arrange themselves in long rows.
If the ion beam knocks out further atoms next to them, the gallium pairs cannot slip down the step that has been created
because the temperatures are too low for this to happen. This is how the long rows of gallium pairs form nano-dunes after a period of time, in
While the individual atoms in a natural material cannot be rearranged with pinpoint precision on such a grand scale,
#Physicists determine 3-D positions of individual atoms for the first time Atoms are the building blocks of all matter On earth,
Now, scientists at UCLA have used a powerful microscope to image the three-dimensional positions of individual atoms to a precision of 19 trillionths of a meter,
to infer the macroscopic properties of materials based on their structural arrangements of atoms, which will guide how scientists and engineers build aircraft components, for example.
For more than 100 years, researchers have inferred how atoms are arranged in three-dimensional space using a technique called X-ray crystallography,
However, X-ray crystallography only yields information about the average positions of many billions of atoms in the crystal
and not about individual atoms'precise coordinates.""It's like taking an average of people On earth,
"Because X-ray crystallography doesn't reveal the structure of a material on a per-atom basis,
the technique can't identify tiny imperfections in materials such as the absence of a single atom.
and measures how many electrons interact with the atoms at each scan position. The method reveals the atomic structure of materials
because different arrangements of atoms cause electrons to interact in different ways. However, scanning transmission electron microscopes only produce two-dimensional images.
769 atoms in the tip of the tungsten sample. The experiment was time consuming because the researchers had to wait several minutes after each tilt for the setup to stabilize."
Miao and his team showed that the atoms in the tip of the tungsten sample were arranged in nine layers, the sixth
The researchers believe the defect was either a hole in an otherwise filled layer of atoms
or one or more interloping atoms of a lighter element such as carbon. Regardless of the nature of the point defect, the researchers'ability to detect its presence is significant,
demonstrating for the first time that the coordinates of individual atoms and point defects can be recorded in three dimensions."
Miao and his team plan to build on their results by studying how atoms are arranged in materials that possess magnetism or energy storage functions,
Overtext Web Module V3.0 Alpha
Copyright Semantic-Knowledge, 1994-2011