Sentences with phrase «metal atoms in»

Not exact matches

For example, when physicists explain the electrical conductivity of metals in terms of the «band structure» of the energy levels of the electrons in a crystal lattice of atoms, to which of the four causes does that correspond?

Clay minerals consist of crystals in which atoms of silicon, oxygen and a number of metals, such as aluminum, iron and various rarer and less frequent ones, are arranged in a three - dimensional lattice.

For example, the presence of hydrogen and methane are clues that the chemical environment of the fluid in which the diamond crystallized was one in which the metal atoms could easily gain electrons and disengage from carbon atoms.

Ti (3) SiC (2) was the first MAX phase Drexel researchers tried to selectively etch in 2011, but synthesis failed using hydrofluoric acid alone because the silicon atoms are strongly bound to the adjacent transition metal atoms.

Seeking such a strategy, researchers at Northwestern University in Evanston, Illinois, created an organic ring - shaped molecule with four metal atoms: two zincs and two rhodiums.

This technique, described in the Feb. 2 Physical Review Letters, showed that 2 - D semiconductors arranged in single - atom - thick sheets expand more like plastics than metals when heated.

In fact, the heat response of the single - atom - thick semiconductors is «more like [that] of a plastic than a metal,» Mecklenburg says.

The arrangement of atoms in an alloy changes the chemical properties of its constituent metals and makes it potentially useful to catalyse reactions.

However, the so called «displacements - per - atom» (dpa) number obtained from this equation does not in common metals usually correspond to any physically measurable quantity.

Carefully tuned in the laboratory, these coatings can produce a bright, solid pink — or, say, a vivid blue — using the same two metals, applied with only a few atoms» difference in thickness.

This latest study looked at how the soft element arsenic interacts with thorium, because arsenic could in principle be used in organic molecules that bond to metal atoms and improve extraction processes.

When the metal is bent or stressed, planes of atoms in the grains slide past one another, sometimes causing crystalline defects to connect with each other — producing fractures.

The cathode material in lithium batteries is typically «ordered,» meaning the lithium and transition metal atoms are arranged in neat layers, allowing lithium to move in and out of the layers.

But in our process the atoms driving catalysis have no metal atoms next to them.

But on an atomic scale, it has remarkable properties: on magnetite, single metal atoms are held in place, or they can be made to move across the surface.

Among other things, they can now better predict the behavior of electrons in graphene, a flat sheet of carbon just a single atom thick, which acts like a strange metal under certain conditions.

As long as the gold atoms, or cations, are stabilized in a single - site form configuration, irrespective of the type of support, the precious metal will be stable and operate for many hours at a range of practical temperatures.

This innovative land mine detector can find explosives that are not encased in metal by detecting the hydrogen atoms that comprise the devious war devices.

That calculation requires measuring the x-rays» intensity and determining their phase, the relative timing — a harder problem traditionally solved by comparing the diffraction pattern from a pure crystal with one from a similar crystal in which heavy metal atoms substitute for some components of the crystal.

In recent years researchers have achieved better performance with compounds such as lithium borohydride, in which the metal atoms form weaker, ionic bonds with groups containing several hydrogen atomIn recent years researchers have achieved better performance with compounds such as lithium borohydride, in which the metal atoms form weaker, ionic bonds with groups containing several hydrogen atomin which the metal atoms form weaker, ionic bonds with groups containing several hydrogen atoms.

Specifically, computer simulations suggested which amino - acid building blocks should comprise the future transporter, so that it would carry ionic atoms of metal zinc in one direction across membranes, while pumping protons in the other.

Surprisingly, it is unclear what happens when an X-ray is absorbed, for example, in biological tissue consisting of water, biomolecules and some metal atoms.

The lens manufacturer Nion Co. in Kirkland, Washington, has found a way to tighten the beam so that atoms situated behind other atoms are clearly visible, as are heavy - metal atoms that were previously undetectable.

I knew that heme, the oxygen - carrying molecule in hemoglobin, contained an iron atom within a porphyrin ring (for more information on porphyrin chemistry see this site at Washburn University), but Dr. Datta - Gupta and his laboratory technician attempted to chemically add different metals such as copper, magnesium, or manganese to porphyrins using column chromatography.

POMs are molecular transition metal - oxygen clusters in which the metal atoms are bridged by oxygen atoms to form a three - dimensional network.

In recent years, the have presented important new findings about the structure of metal oxides, about the mobility of atoms on their surface and their chemical properties.

Nevalaita and Koskinen created three periodic tables that chart the properties of 2 - D metals with atoms in triangular, square or honeycomb configurations.

Aside from the demonstration that metal atoms can form freestanding 2D membranes there is significant interest in the potential of such 2D metal materials as they are expected to have exotic properties.

In these structures ligands, which are organic or inorganic molecules of variable independent stability, bind to one or more transition metal atoms.

For instance, atoms of any given metal arranged in a triangular lattice typically had about 70 percent the bond strength of atoms in the 3 - D version of that metal.

The formation of 2D atomically thin metallic layers over other surfaces has previously been demonstrated, however in this case the metal atoms interact with the underlying substrate.

The term is generally reserved for complexes in which the metal ion is bound to two or more atoms of the chelating agent, although the bonds may be any combination of coordination or ionic bonds.

Artistic impression of the squeezed light (plasmon) in between the metal and graphene, separated by a one - atom thick dielectric.

Nevalaita and Koskinen also compared the stability of 2 - D metals whose atoms were arranged in the three different configurations.

But whereas those materials were made up of covalent bonds — in which pairs of atoms share electrons — these 2 - D metals are composed of metallic bonds, where electrons flow more freely among atoms.

«We might be able to open up a new kind of chemistry where elements could be simulated with metals — in this case aluminum — of different numbers of atoms.»

ULTRATHIN FILMS Computer simulations reveal the properties of a little - studied group of synthetic materials: 2 - D arrays of metal atoms arranged in honeycombs (illustrated), triangles or squares.

To understand how they work, we can take a look at nature itself: while natural elements acquire their physical properties from the atoms that form them and the way in which they are ordered, metamaterials use natural means, like small metal fragments that fit together like parts of a Meccano model to artificially synthesise properties that are impossible to find otherwise.

Meyer, a chemist at University of North Carolina at Chapel Hill and director of its Energy Frontier Research Center in Solar Fuels, noticed that two separate groups of researchers working on two separate parts of the photosynthetic reaction happened to be using the same class of catalyst — ones with an atom of the metal ruthenium surrounded by organic molecules.

«In essence,» said co-author Darren W. Johnson, a professor of chemistry, «we can prepare one type of nanoscale cluster compound, and then step - by - step substitute out the individual metal atoms to make new clusters that can not be made by direct methods.

The process described in the paper represents a new approach to transmetalation, in which individual atoms of one metal complex — a cluster in this case — are individually substituted in water.

Melanie Sanford, a chemist the University of Michigan, Ann Arbor, who focuses on using metal - based agents, primarily palladium, to catalyze reactions that substitute hydrogen in carbon - hydrogen bonds with other atoms or functional groups.

The Kondo effect, first described last century by the Japanese physicist Jun Kondo, is observed when magnetic impurities, i.e., very few atoms (even only 1 in 1000) of magnetic material such as iron are added to metals like gold or copper.

Specifically, a metal - organic framework compound, copper [1,3 - benzenedicarboxylate] with a unique arrangement of copper atoms in a crystal, has been shown to exhibit this novel behavior.

He knew he needed to find metals that were deft at breaking the carbon - hydrogen bonds that are at the heart of methane, ethane, and propane, short hydrocarbons known as alkanes, and then add in oxygen atoms that would transform the alkanes into alcohols.

Inside its three - story metal sphere researchers can interpret and interact with their data in new and intriguing ways, including watching electrons spin from inside an atom or «flying» through an MRI scan of a patient's brain as blood density levels play as music.

In metals, for instance, electrons freely flow around and between atoms.

«We were excited to find that the platinum metal dissolved in copper, just like sugar in hot coffee, all the way down to single atoms.

In the early 2000s, Maria's group had pioneered the single - atom approach for metals anchored on oxide supports as the exclusive active sites for the water - gas shift reaction to upgrade hydrogen streams for fuel cell use.

After decades of eluding researchers because of chemical instability, key metal - oxide clusters have been isolated in water, a significant advance for growing the clusters with the impeccable control over atoms that's required to manufacture small features in electronic circuits.