Science

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A quantum magnet with a topological twist: Materials with a kagome lattice pattern exhibit 'negative magnetism' and long-sought 'flat-band' electrons

Taking their name from an intricate Japanese basket pattern, kagome magnets are thought to have electronic properties that could be valuable for future quantum devices and applications. Theories predict that some electrons in these materials have exotic, so-called topological behaviors and others behave somewhat like graphene, another material prized for its potential for new types of electronics.

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esearchers explored a material that has an internal structure, shown in 3D in left panel, that consists of triangles and hexagons arranged in a pattern similar to that of a Japanese kagome basket.

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Avoiding the Crack of Doom: New imaging technique reveals how mechanical damage begins at the molecular scale

Just as a journey of 1,000 miles begins with a single step, the deformations and fractures that cause catastrophic failure in materials begin with a few molecules torn out of place. This in turn leads to a cascade of damage at increasingly larger scales, culminating in total mechanical breakdown. That process is of urgent interest to researchers studying how to build high-strength composite materials for critical components ranging from airplane wings and wind-turbine blades to artificial knee joints.

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The researchers compared calculated images of single molecules in different orientations (left) with experimental ones (right) to determine the 3D alignment of the fluorescent molecules in a sample. 1 µm is one micrometer, about 1/100th the width of a human hair.

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Exotic spiraling electrons discovered by physicists: Rutgers-led research could lead to advances in lighting and solar cells

Rutgers and other physicists have discovered an exotic form of electrons that spin like planets and could lead to advances in lighting, solar cells, lasers and electronic displays.

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The two types of 'chiral surface excitons' are on the right and left side of the image. They are generated by right- and left-handed light (photons in blue). The excitons consist of an electron (light blue) orbiting a 'hole' (black) in the same orientation as the light. The electron and hole are annihilated in less than a trillionth of a second, emitting light (photons in green) that could be harnessed for lighting, solar cells, lasers and electronic displays.

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Straightforward biosynthesis of functional bulk nanocomposites

Interest in constructing bulk nanocomposite materials from biosourced and renewable nanoscale building blocks is growing. As a crystalline cellulosic polymer, cellulose is the most abundant biosourced and renewable polymeric material on earth, which can be extracted from plant or produced by bacteria. Bacterial cellulose (BC) nanofibrils possess a high tensile strength as high as steel and Kevlar and spontaneously formed a robust three-dimensional (3D) nanofibrous network, which makes it an ideal platform for design of functional bulk nanocomposites. BC and its nanocomposites have been widely used in many fields, including acoustic membrane, electron device, energy storage and catalyst. However, the conventional process for fabricating uniform BC nanocomposites involved the disintegration of 3D network structure for solution processing, which seriously impaired the mechanical performance of the nanocomposites. So, strategies without disintegration the 3D network structure are core important for constructing bulk BC based nanocomposites.

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The biosynthesis strategy of functional bulk nanocomposites. a, Scheme of the bioreactor. Aerosols of liquid nutrient and nanoscale building block suspensions were fed into the bioreactor with filtered compressed air, which was controlled by an automatic control system. b to d, Schematic illustration of the formation uniform BC-based nanocomposites with 0D nanoparticles (b), 1D nanotubes or nanowires (c), and 2D nanosheets (d). e, Photograph of a large-sized CNTs/BC pellicle with a volume of 800×800×8 mm3. f, Comparison of the tensile strength of the biosynthesized CNTs/BC nanocomposites with blended CNTs/BC nanocomposites. g, Electrical conductivity of the CNTs/BC films as a function of CNTs volume and weight fraction.

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Kanazawa University research: Chirality inversion in a helical molecule at controlled speeds

A strategy to invert the chirality of a metal-containing helical molecule controlling the speed of the response is reported in Chemistry

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Scheme 1 from the paper

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Physicists uncover new competing state of matter in superconducting material

A team of experimentalists at the U.S. Department of Energy's Ames Laboratory and theoreticians at University of Alabama Birmingham discovered a remarkably long-lived new state of matter in an iron pnictide superconductor, which reveals a laser-induced formation of collective behaviors that compete with superconductivity.

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Ames Laboratory researchers used laser pulses of less than a trillionth of a second in much the same way as flash photography, in order to take a series of snapshots. Called terahertz spectroscopy, this technique can be thought of as "laser strobe photography" where many quick images reveal the subtle movement of electron pairings inside the materials using long wavelength far-infrared light.

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DNA design that anyone can do: Computer program can translate a free-form 2-D drawing into a DNA structure

Researchers at MIT and Arizona State University have designed a computer program that allows users to translate any free-form drawing into a two-dimensional, nanoscale structure made of DNA.

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MIT researchers have devised a technique that “reverse engineers” complex 3-D computer-aided design (CAD) models — breaking them down into the many individual shapes they’re made of — to make them far easier for users to customize for manufacturing and 3-D printing applications.

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Holiday Asteroid Imaged with NASA Radar

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These three radar images of near-Earth asteroid 2003 SD220 were obtained on Dec. 15-17, by coordinating observations with NASA's 230-foot (70-meter) antenna at the Goldstone Deep Space Communications Complex in California and the National Science Foundation's (NSF) 330-foot (100-meter) Green Bank Telescope in West Virginia.

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E-bandage generates electricity, speeds wound healing in rats

Skin has a remarkable ability to heal itself. But in some cases, wounds heal very slowly or not at all, putting a person at risk for chronic pain, infection and scarring. Now, researchers have developed a self-powered bandage that generates an electric field over an injury, dramatically reducing the healing time for skin wounds in rats.

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A wound covered by an electric bandage on a rat's skin (top left) healed faster than a wound under a control bandage (right).

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Mars Express gets festive: A winter wonderland on Mars

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Perspective view of Korolev crater