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。
Liquid crystals are interesting both for fundamental reasons and because of their application in display device technology. I give an overview of the liquid crystal phases. I then describe in more detail some of the basic physics of nematic liquid crystals, concentrating on those pieces of physics which underly displa…
Active packaging is one of the innovative food packaging concepts that has been introduced as a response to the continuous changes in current consumer demands and market trends. Major active packaging techniques are concerned with substances that absorb oxygen, ethylene, moisture, carbon dioxide, flavours/odours and t…
A series of polyurethanes containing silicon and phosphorus was prepared from 4,4′-diphenylmethane diisocyanate (MDI), poly(tetramethylene ether glycol) (PTMG), diphenylsilanediol (DSiD), and methylphosponic acid (MPA). 1H-NMR spectra determined the qualitative and quantitative characteristics of these polymers. The t…
Thin solid films of hydroxyethylcellulose/oligoether were obtained by a grafting reaction of HEC with diisocyanates, and were then characterized by DSC, FTIR, NMR and complex impedance techniques. The transparency of these films in the visible range of the electromagnetic spectrum, the low Tg, the good chain mobility…
The surface activation process of sputter-coated non-evaporable getter (NEG) thin films based on Ti–Zr and Ti–Zr–V alloys has been studied in situ by means of x-ray photoelectron spectroscopy. After exposure of the NEG thin films to ambient air they become reactivated after a thermal treatment in an ultrahigh vacuum.…
The cooling of Pb 1− x Ba x Sc 0.5 Nb 0.5 O 3 solid solutions with x ≤0.04 leads to a spontaneous transition from a relaxor to a macrodomain ferroelectric state, accompanied by anomalous variation of the dielectric and optical properties of the material. As the barium content in the system increases, the relaxor state…
Low Tg copolymers of [11(N-carbazolyl)undecylmethacrylate] and [2,5-dimethylphenyl-[(4-nitrophenyl)azo]-phenoxyalkylmethacrylate] have been synthesized and the polarized light-induced birefringence of thick films (70 μm) has been investigated at a constant deducted temperature relative to Tg (T − Tg = 10 °C). The opti…
A mathematical model is developed to simulate the rheological behavior of fabric bagging. The model is based on the assumption that stress-strain relationships in fabric consist of three essential components: elastic deformation and viscoelastic deformation of fibers and the friction between fibers and yarns within th…
The synthesis, characterization and X-ray structure of an hexapyrrolic macrocycle, [26]hexaphyrin(1.1.1.1.0.0), is reported; it is characterized by a partially inverted structure.
Tubes from zirconium-base alloys are used widely in the pressure tube reactor core. The lifetime of the zirconium component in the reactor core will be determined by structure changes and alloy properties under long-term neutron irradiation. The studies were carried out using Zr-1Sn-1Nb-0.4Fe (E635) and Zr-2.5Nb (E125…
The synergistic activity of binary accelerator systems in rubber vulcanization is well known. Thiourea and its derivatives are important secondary accelerators in this context. It is suggested that thiourea containing binary systems of rubber vulcanization proceed by a nucleophilic reaction mechanism. Amidinothioureas…
Crystallization behavior of natural rubber prepared by different procedures, such as skim rubber, deproteinized natural rubber (DPNR), and pale crepe, was investigated by dilatometry at −25°C. DPNR was fractionated into four fractions by molecular weight. The high molecular weight fractions contained about 1.7 linked…
A method for the calculation of atomic polarizabilities based on the variational method for the calculation of the electronic polarizability in terms of the neglect of differential diatomic overlap (NDDO) approximation is presented. The resulting atomic polarizability tensors are additive. Calculation of an extended t…
Based on a multiscale asymptotic technique, a weakly nonlinear theory of rectified heat transfer to vapor bubbles is developed. The theory takes into account effects of internal and external heat transfer near the bubbles including memory terms, viscosity and slight compressibility of the liquid, surface tension, and…
Melt blending of thermoplastic polyurethane (TPU)/ammonium polyphosphate (APP) additives in a polypropylene matrix improves fire proper ties of the polypropylene-based materials via an intumescence process. In this study, the protective effect of intumescence is studied considering the thermal stability of a particula…
An X-ray crystal structure of the methylbenzodithiazolyl radical MeC6H3S2N˙, MBDTA, reveals that it forms a regularly spaced π-stack motif in the solid state; variable temperature magnetic studies show that the susceptibility passes through a broad maximum at 140 K indicative of exceptionally strong antiferromagnetic…
The excitation of the triplet exciton leading to the "long‐lived" photoluminescence characteristic of a porous silicon (PS) surface has been used to selectively enhance the highly efficient, controlled, and patterned plating of copper and silver metal from electroless solutions. The basis of this method lies in the us…
Two derivative ligands of diethylenetriamine-N,N,N′,N′′,N′′-pentaacetic acid (H5DTPA; H5L1) were synthesized: the symmetric and asymmetric mono(methylamides) DTPA-N′-MA (H4L3) and DTPA-N-MA (H4L4). The protonation constants (log KiH) of L3 and L4 were obtained by pH-potentiometric titration: 10.04, 8.41, 2.73, 1.94 an…
Photoelectrochemical experiments have been carried out for characterizing passive films on Mo‐Ta sputtered alloys having different compositions, as well as on pure Mo and Ta metals. Both corrosion layers, formed by simple immersion in solution, and films grown anodically were investigated. The presence of Mo species i…
In this paper we examine nonradiative processes (cross relaxation and energy migration) vital for the generation of blue avalanche emission in ${\mathrm{T}\mathrm{m}:\mathrm{L}\mathrm{i}\mathrm{Y}\mathrm{F}}_{4}$ crystals subjected to radiation near 648 nm. Time-domain and temperature-dependent measurements indicate t…