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。
1. The morphologically complex taxon Cyclotella comensis Grunow had no clear relationship with environmental parameters in a study using sediment surface samples from the Swiss Alps. The morphological heterogeneity of the taxon was investigated by applying a principal component analysis (PCA) to 9000 presence/absence…
Poly(vinyl alcohol) (PVA) was added water suspension of perylene nanocrystals prepared through the reprecipitation method. The growth of the nanocrystals can be sustained by the protecting effect of PVA. At the same time, the monomer emission of perylene nanocrystals is enhanced and the lifetime of the excited state i…
Nanocrystalline nickel particles were embedded in amorphous alumina and crystalline TiN matrices using a pulsed-laser deposition process to investigate the effect of texturing on magnetic properties of nickel nanocrystallites. The crystalline quality of both the matrix and magnetic particles were investigated by cross…
Abstract Oil palm fiber empty fruit bunch (EFB) was chemically treated with benzyl chloride (bz‐efb) and ethylene oxide (E‐efb) at different reaction temperatures (100 and 110°C for bz‐efb; 55, 85, and 92°C for E‐efb). The SEM micrographs of bz‐efb and E‐efb samples showed tremendous changes in morphological structure…
We study the temporal evolution of both the second-order nonlinear coefficient and of the nonlinear thickness in thermally poled silica-glass slides by using a high-resolution all-optical technique. A time delay in the nonlinearity formation is observed, followed by an increase to a maximum, and a final decrease. The…
The time correlation functions of the electronic spin components of a metal ion without orbital degeneracy in solution are computed. The approach is based on the numerical solution of the time-dependent Schrödinger equation for a stochastic perturbing Hamiltonian which is simulated by a Monte Carlo algorithm using dis…
Arrays of vertically aligned carbon nanotubes (CNTs) were grown on a patterned sputtered cobalt film by chemical vapor deposition from ethylenediamine at 900 °C. Each square array comprises a moderate density of nanotubes with an average height of 90 μm covering a total area of 3.6×10−3 cm2. Field emission measurement…
The change in surface composition and structure of a rutile TiO2(110) surface during thermal annealing in an ultrahigh vacuum was studied by coaxial impact–collision ion scattering spectroscopy and time-of-flight elastic recoil detection analysis. When the clean TiO2(110) surface with a 1×1 bridging-oxygen-rows struct…
We present an approach to electronic polarization in molecular solids treated as a set of quantum systems interacting classically. Individual molecules are dealt with rigorously as quantum-mechanical systems subject to classical external fields created by all other molecules and, possibly, external sources. Self-consi…
We report unambiguous experimental evidence for an achiral orthogonal biaxial smectic-A phase which exhibits antiferroelectric switching behavior. The evidence is based on x-ray-diffraction measurements, texture observation, and the results of dielectric and electro-optical measurements.
Equations are proposed for computing from ab initio wave functions quantities like 〈SA⋅SB〉, which appear in the Heisenberg model Hamiltonian of magnetism. These equations are based on projection operators derived from Löwdin orthogonalization. They result in local spin operators SA which obey the definition of angular…
The crystal structures of Bi4Ti3O12 and Bi3.25La0.75Ti3O12 were refined by neutron powder diffraction. Large structural distortions were revealed, and ferroelectric polarizations along the a and c axes were calculated from the displacements of the constituent ions. In Bi3.25La0.75Ti3O12, La atoms substitute for Bi ato…
We report the magnetization and the susceptibility measurements of the RuSr_2GdCu_2O_y and RuSr_2NdCu_2O_x perovskite materials. We find that RuSr_2GdCu_2O_y compound exhibits a magnetic transition at Tn=135 K followed by a superconducting one with an onset Tc=35 K. Samples of RuSr_2NdCu_2O_x material have shown neith…
First-principles density-functional calculations within the local-density approximation and the pseudopotential approach are used to study and characterize the ferroelastic phase transition in calcium chloride (CaCl_2). In accord with experiment, the energy map of CaCl_2 has the typical features of a pseudoproper ferr…
The energy radiated by moving cracks in a discrete background is analyzed. The energy flow through a given surface is expressed in terms of a generalized Poynting vector. The velocity of the crack is determined by the radiation by the crack tip. The radiation becomes more isotropic as the crack velocity approaches the…
The out-of-equilibrium low-frequency complex susceptibility of the orientational glass methanol(73%)-beta-hydrochinone-clathrate is studied using temperature-stop protocols in aging experiments . Although the material does not have a sharp glass transition aging effects including rejuvenation and memory are found at l…
A combined study with use of time-domain pump-probe spectroscopy and time-domain terahertz transmission spectroscopy have been carried out on an underdoped Bi$_2$Sr$_2$CaCu$_2$O$_{8+δ}$ thin film. It was observed that the low energy multi-excitation states were decomposed into superconducting gap and pseudogap. The ps…
We report a detailed study of the electronic structure of the MgB$_{2}$ with different lattice constants by using the full-potential linearized augmented plane wave(FPLAPW) method. It is found that the lattice parameters have great effect on the $σ$ band of Boron. Our results indicate that increasing lattice constant…
Ionic-pair equal-time displacement correlations in relaxor lead magnesium niobate, $\mathrm{Pb}({\mathrm{Mg}}_{1/3}{\mathrm{Nb}}_{2/3}){\mathrm{O}}_{3},$ have been investigated at 300, 270, and 240 K in terms of an x-ray diffuse scattering technique. Functions of the distinct correlations have been determined quantita…
A beautiful and intriguing relationship has recently been proposed to express the critical screening lengths associated with the apparition of new bound states for the two-dimensional statically screened Coulomb potential. Semiclassical quantum theory show that this relationship is unfortunately not strictly exact. Th…