Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
Synthetic K-rich birnessites (KBi) were prepared from the thermal decomposition of a fine-grained KMnO 4 powder heated in an air atmosphere at temperatures ranging from 200 to 1000 °C. The qualitative analysis of powder X-ray diffraction (XRD) patterns reveals a complex range of structural transformations from one met…
Using a variety of spectroscopic techniques, a number of molecular functionalities have been studied in relation to the adsorption process of proteins to air-water interfaces. While ellipsometry and drop tensiometry are used to derive information on adsorbed amount and exerted surface pressure, external reflection cir…
We investigate dynamic heterogeneities in liquid water by performing molecular dynamics simulations of the SPC/E model. We find clusters of mobile molecules. We study the temperature and time dependence of the cluster size and find that clusters grow as temperature decreases and have a maximum size at the time scale c…
Abstract This study is concerned with the temperature and molecular weight dependence of the strain‐hardening behavior of polycarbonate. It is shown that the strain‐hardening modulus reduces with increasing temperature and decreasing molecular weight. This result is interpreted in terms of temperature accelerated rela…
The structure of 3 nm ZnS nanoparticles differs from that of bulk ZnS and is shown to vary with the particle aggregation state. Dispersed or weakly aggregated nanoparticles in suspension have a more distorted internal structure than strongly aggregated nanoparticles. Reversible switching between distorted and crystall…
Single site, functionalized, single stranded (ssDNA) dendri- poly(amidoamine) (PAMAM) di-dendrons have been synthesized by covalently conjugating complementary 32 base pair oligonucleotides to single-site, thiol functionalized dendri -PAMAM di-dendrons possessing neutral or anionic surface groups. Combining these comp…
Abstract A study was made of yield and plastic flow in glassy polystyrene. A range of 12 linear atactic polystyrenes was studied: monodisperse, bimodal blends, and a polydisperse commercial sample. M n varied between 66,000 and 490,000 g/mol. These were given standardized thermal treatments and then subjected to uniax…
Cellulose constitutes an important raw material for many industries. However, the superb load-bearing properties of cellulose are accompanied by poor chemical reactivity. The hydroxyl groups on cellulose surfaces can be reacted but usually not without loss of fiber integrity and strength. Here, we describe a novel che…
Spidroins, the major silk proteins making up the spider's dragline silk, originate in two distinct tissue layers (A and B) in the spider's major ampullate gland. Formation of the complex thread from spidroins occurs in the lumen of the duct connected to the gland. Using pH-sensitive microelectrode probes, we showed th…
We report our systematic studies of the environmental effects on the photoluminescence (PL) from colloidal CdSe nanocrystals (NCs) embedded in polymer thin films. The highly luminescent bare-core CdSe NCs were significantly more robust than the core/shell CdSe/ZnS NCs against photoannealing under inert environments, w…
We compute the decoherence caused by $1/f$ fluctuations at low frequency $f$ in the critical current $I_0$ of Josephson junctions incorporated into flux, phase, charge and hybrid flux-charge superconducting quantum bits (qubits). The dephasing time $τ_ϕ$ scales as $I_0/ ΩΛS_{I_0}^{1/2}(1$ Hz$)$, where $Ω/ 2π$ is the e…
Vibrational spectra of closed shell Lennard-Jones icosahedral and cuboctahedral clusters are calculated for shell numbers between 2 and 9. Evolution of the vibrational density of states with the cluster shell number is examined and differences between icosahedral and cuboctahedral clusters described. This enabled a qu…
The formation of atomic wires via pseudomorphic step-edge decoration on vicinal silicon surfaces has been analyzed for Ga on the Si(112) surface using Scanning Tunneling Microscopy and Density Functional Theory calculations. Based on a chemical potential analysis involving more than thirty candidate structures and con…
Temperature-controlled-growth of silver nanoclusters in soda glass matrix is investigated by low-frequency Raman scattering spectroscopy. Growth of the nanoclusters is ascribed to the diffusion-controlled precipitation of silver atoms due to annealing the silver-exchanged soda glass samples. For the first time, Ruther…
We extend our earlier shear-transformation-zone (STZ) theory of amorphous plasticity to include the effects of thermally assisted molecular rearrangements. This version of our theory is a substantial revision and generalization of conventional theories of flow in noncrystalline solids. As in our earlier work, it predi…
Energy band structure of the discovered ternary perovskite-like compound ZnCNi3 reported by Park et al (2004) as a non-superconducting paramagnetic metal was investigated using the FLMTO-GGA method. The electronic bands, density of states, Fermi surface, charge density and electron localization function distributions…
The motions of liquid drops of various surface tensions and viscosities were investigated on a solid substrate possessing a gradient of wettability. A drop of any size moves spontaneously on such a surface when the contact angle hysteresis is negligible; but it has to be larger than a critical size in order to move on…
The smaller the better: Depositing gold on nanocrystalline particles of cerium oxide, instead of a regular cerium oxide support, increases the activity of the resulting catalyst by two orders of magnitude for the selective oxidation of CO to CO2, even in the presence of H2 (shown schematically).
The transition of the magnetic state with x increasing in electron-doped manganite Nd1−xCexMnO3 is investigated through the measurements of magnetism, including the M–T and hysteresis curves. For x=0.04, with temperature increasing, M under zero-field cooling indicates that the magnetic structure changes from ferromag…
The observation that a molecular electron density is close to the superposition of its constituent atoms leads naturally to the idea of modeling a density by a sum of nuclear-centered, spherically symmetric functions. The functions that are optimal in a least-squares sense are known as Stewart atoms. Previous attempts…