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 fluorescence properties of Sm3+ and Sm2+ ions incorporated in silicate glasses were measured using steady-state and laser-induced line narrowing techniques and the effect of Al3+ ions to the local structure around the Sm2+ ion was investigated. Sm3+ ion-containing glasses prepared by a sol–gel method were reacted…
An experiment involving the shaking of sets of different sided dice is described. Dice of 4, 6, 8, 10, 12 and 20 sides are readily available. This experiment serves as an easily understood analogy for radioactive decay and for the more general case of first order kinetics. The shaking of one of the possible numbers on…
We trace the development of the ON/ONO dielectric film and examine the potential of new dielectrics with high dielectric constants such as Ta/sub 2/O/sub 5/ and ferroelectric materials. We also examine hemispherical grained (HSG) polysilicon, which is an innovative way to increase the effective area of the capacitor.
Various methods allowing onboard hydrogen generation for fuel cell powered electric cars are reviewed. The following primary fuels are considered : ammonia, methanol, ethanol, and hydrocarbons. The catalytic cracking of ammonia allows generation of a CO2-free mixture containing 75% hydrogen, which is consequently suit…
We have grown nickel doped boron–carbon alloy films by the technique of plasma enhanced chemical vapor deposition. The source gas closo-1,2-dicarbadodecaborane (orthocarborane) was used to grow the boron–carbon alloy, while nickelocene [Ni(C5H5)2] was used as the dopant source for nickel. With sufficient levels of Ni…
We have used pressure−area isotherms, X-ray diffraction, atomic force microscopy, and infrared dichroism to study Langmuir and Langmuir−Blodgett films of 2,3,6,7,10,11-hexaalkoxytriphenylenes which were selectively di- and trifunctionalized with C n H 2 n −OH groups at the 2,3-, 2,6-, 3,6-, and 3,6,10-positions. The b…
A set of linked software modules has been installed at the A1 station of CHESS, the Cornell High Energy Synchrotron Source, which, with the underlying hardware, allows crystallographic users of the facility to evaluate crystals, collect diffraction images and process the images rapidly and with assurance of the qualit…
An investigation was undertaken to characterize the time progression of the Pt etch process during the dry etching (DE) of fence-free patterned structures. The goal of this study was to clarify the mechanism of fence-free Pt etching. In particular an explanation was sought that could account for the origin of the extr…
Abstract Oxisols contain stable aggregates, and sorption and desorption kinetics for aggregates typically are slower than for disaggregated samples. The objectives of this research were to determine whether aggregation inhibits Fe and Al extraction more in large than small aggregates, and to determine whether aggregat…
A macromodel for nonlinear devices exhibiting hysteresis is presented. Although this model is based on existing ideas of ferromagnetic hysteresis, it can be applied to all hysteresis phenomena by choosing suitable parameters. It consists only of four algebro-differential equations with ten parameters and exhibits all…
Atomistic simulation represents a valuable methodology for interpreting and predicting surface structures. The emphasis of our work is to develop and apply this approach to understanding the role of surface defects and additives in modifying the structure and stability of mineral surfaces. The basis of our approach is…
A new model of ferroelectric phase transitions in disordered crystals is developed. The model takes into account the nonequivalence of the structural environment of identical ions, which alters the balance of forces governing ferroelectric structural instability. In contrast with its predecessors, the new model can be…
Abstract Low‐molecular‐weight poly(ethylene oxide)‐polyalkane (PEO‐PA) diblock copolymers have been examined between the order‐disorder transition and PEO melting temperature using small‐angle neutron scattering (SANS), differential scanning calorimetry (DSC), and dynamic mechanical spectroscopy (DMS). Crystallization…
Transmission high‐energy electron holography has been utilized to quantitatively determine the magnitude, sign, and spatial extent of the electrical potential, electric field, as well as the charge and stress field distributions across electrically active grain boundaries (GBs) in polycrystalline SrTiO 3 . The polycry…
Properties of two-center Coulomb Sturmian basis sets are discussed. Analytic and numerical techniques to calculate these functions and coupling matrix elements are developed. A class of Sturmian functions is found that has no analytic continuation to negative energies and is not present in one-center potentials. Advan…
The various magnetic structures and magnetic phase transitions in the series ${\mathrm{Nd}}_{\mathrm{x}}$${\mathrm{Tb}}_{1\mathrm{\ensuremath{-}}\mathrm{x}}$${\mathrm{Mn}}_{2}$${\mathrm{Ge}}_{2}$ have been thoroughly studied by means of macroscopic magnetic and thermal measurements (such as magnetization, ac initial m…
Abstract Various aniline derivatives carrying one or two alkyl substituents in various positions (alkylanilines, toluidines and xylidines) were polymerized electrochemically. The obtained conducting polymers were characterized by cyclic voltammetry, in situ infrared spectroscopy and in situ conductivity measurements.…
Arenicola marina possesses cuticular and interstitial collagens, which are mostly synthesised by its epidermis. A cDNA library was constructed from the body wall. This annelid cDNA library was screened with a sea-urchin-collagen cDNA probe, and several overlapping clones were isolated. Nucleotide sequencing of these c…
beta-Hydroperoxy alcohols 1-4 serve as effective tridentate oxygen donors for the highly diastereoselective, titanium-catalyzed epoxidation of ene diols 5a-e. Thus, in contrast to the bidentate tert-butyl hydroperoxide, the usual oxygen donor employed in Sharpless-type epoxidations and known to work poorly for polyhyd…
Abstract We report on the phase behavior and microdomain structure of two types of diblock copolymers containing a liquid crystal (LC) block joined to a flexible coil block. Consideration of the symmetry groups of the liquid crystalline phases and of the block copolymer microdomain structures provides a rationale for…