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。
The connection between the crystallographic phase problem and the feasible set approach is explored. It is argued that solving the crystallographic phase problem is formally equivalent to a feasible set problem using a statistical operator interpretable via a log-likelihood functional, projection onto the non-convex s…
Poly(imide–silica) hybrid materials with covalent bonds were prepared by (3-aminopropyl)methyldiethoxysilane (APrMDEOS) terminated amic acid, water, and tetramethoxysilane (TMOS) via a sol–gel technique. Infrared (IR), 29Si and 13C CP/MAS nuclear magnetic resonance (NMR) spectroscopy, and thermogravimetric analysis (T…
Simultaneous piezoelectric microgravimetry and cyclic voltammetry (CV) at an electrochemical quartz microbalance have been used to monitor the growth of poly(neutral red) films on the gold and graphite electrodes during potential cycling between –0.7 V and 0.75 V (vs. SCE) in sodium phosphate buffer (pH 5.3) and NaNO3…
The dissolution rates of most primary and secondary minerals are promoted by the presence of proton‐ and complex‐forming ligands. Effects on the rates of dissolution of hornblende by naturally occurring organic acids at concentrations commonly encountered in soil solutions and surface waters was studied in a pH 4.0, 0…
ABSTRACT Average cholesterol reduction increased as β‐cyclodextrin concentration increased, regardless of other factors. The process was optimized using RSM. When β‐cyclodextrin addition was 10%, the effect of stirring speed was more noticeable than that of stirring time. When stirring speed was at 1,600 rpm, 94.2% of…
Poly(dimethylsiloxane) networks were prepared by tetrafunctionally end-linking hydroxyl-terminated chains with tetraethoxysilane (TEOS). Molecular composites were then prepared by in situ sol–gel reactions on additional TEOS swelled into the networks, resulting in the formation of reinforcing silica fillers within the…
After a brief introduction to discotic liquid crystals, we describe recent progress in elucidating the properties of the columnar phases as one-dimensional electrical conductors (or molecular wires), fast photoconductors, light emitting diodes and ferroelectrics, all of which have potentially important practical appli…
A series of $[{\mathrm{La}}_{2/3}{\mathrm{Ca}}_{1/3}{\mathrm{MnO}}_{3}(\ensuremath{\Lambda}/2)/{\mathrm{La}}_{1/3}{\mathrm{Ca}}_{2/3}{\mathrm{MnO}}_{3}(\ensuremath{\Lambda}/2){]}_{15}$ multilayers, with bilayer thicknesses $\ensuremath{\Lambda}$ between $2$ and 32 nm, has been prepared by pulsed laser deposition. The…
Herein we examine the origin of the high-temperature (350 K) behavior of a thermophilic mutant enzyme (labeled as 5-3H5; see Zhao and Arnold Prot. Eng. 1999, 12, 47−53) derived from subtilisin E by eight amino acid substitutions. Through the use of molecular dynamics (MD) simulations, we have provided molecular-level…
A method for accurate dimensional and angular measurements of microstructures analysed in the scanning electron microscope is described. The method considers central and parallel projections and involves (a) digital image acquisition of stereopaired images from the scanning electron microscope's photodisplay, (b) gene…
Epoxy-anhydride cure has been studied by differential scanning calorimetry under nonisothermal conditions. The isoconversional method of kinetic analysis yields a dependence of the effective activation energy on the extent of conversion (α) that increases from ≈ 20 to 70 kJ·mol–1 with increasing α. The occurrence of t…
A linear elastic solution is proposed for a circular disc in transition from a plate-like (pure bending) to a membrane-like behavior (pure stretching) under a central point load. The strain energy release rate for film delamination is found to be G = χ(Pw 0/πa 2) with χ a numerical constant varying from 1/2 for a plat…
Thin silica–titania films doped with different concentration of PbS quantum dots (PbS/oxide molar ratios ranging from 5% to 25%) were fabricated via a sol-gel route. The structural properties were studied by x-ray diffraction, high-resolution transmission electron microscopy, and Rutherford backscattering spectrometry…
A range of compositions and temperatures below the monotectic temperature exists where there are thermodynamic restrictions that prevent the equilibrium solid from forming directly from the undercooled homogeneous liquid. In this region, the solid can form only after liquid‐liquid phase separation has occurred. As sug…
We report on the microstructure and mechanical properties of diamond films grown using varying nitrogen additions to a plasma with a high-CH4 fraction of 15% (in hydrogen) and an operating pressure of 125 Torr. Films were grown at N2/CH4 ratios ranging from 0 to 0.30 by fixing the CH4 flow rate and changing only the N…
The influence of yttrium doping on the microstructure and microchemistry of hot‐pressed α‐alumina was investigated using a combination of electron microscopy techniques. The implications of microstructure and microchemistry on the improved creep behavior of the doped material are discussed. The samples doped only with…
This symposium was international in nature, with leaders in the fields of fatigue technology and the metallurgy of titanium from the US, Europe and Asia. It covered basic research, development, applications and modeling--life predictions and design of both fatigue crack initiation and propagation of titanium alloys. T…
Thin organic films with interesting magnetic propertiessuch as the magnetic memory effect have been achieved using the Langmuir–Blodgett technique. Results are summarized in this report whereby polyoxometalate anions containing magnetically active transition metals have been incorporated as layers of discrete clusters…
The determination of the detailed chemical nature of oxidized aluminum species is an essential requirement for the study of many important practical aspects associated with aluminum metal and its compounds. While thick oxidized films of aluminum metal can be easily characterized by x-ray powder diffraction when the fi…
We present results for total-energy simulations of the energetics of vacancy occupation of \ensuremath{\gamma} alumina using an empirical potential that allows the ionic valence to vary according to the local environment and includes Coulombic electrostatic interactions among the anions and cations. Our model predicts…