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。
On-line studies of the structural development during continuous drawing of a polypropylene fiber were carried out using synchrotron wide-angle X-ray diffraction. A unique image analysis method was introduced to extract quantitative information on the crystal, amorphous and mesomorphic fractions. In addition, the unit-…
A short-ranged classical force-field for the modeling of silicon nitrides, boron nitrides, and borosilazanes (Si/B/N) has been derived on the basis of experimental and ab initio solid state and diatomic molecular data. The potential is a sum of pure two-body interaction terms with functional forms apt for fraction sim…
Ordered macroporous structures have been produced by templating echinoid (sea urchin) skeletal plates. Results are summarized that describe how the CaCO3 plates that form the test of the sea urchin provide excellent templates for producing porous structures. This extremely general method has been used in this case to…
This study of two new total hand simulating methods for knits uses fuzzy theory and neural networks. One method, a neural network system trained with a back-propaga tion algorithm, performs functional mapping between mechanical properties and the resulting total hand values of the fuzzy predicting method. The second m…
Anisotropic peak broadening in hydrogen-cycled hexagonal LaNi 5 and substitutional derivatives has been studied by means of synchrotron powder diffraction. The data have been analysed by a local lattice parameter variation method implemented in a Rietveld code and by an individual profile fitting using a dislocation p…
Surface photovoltage spectrum (SPS) and field-induced surface photovoltage spectrum (FISPS) are valuable techniques for the determination of pn conduction type of organic semiconductors. Here, conduction characters of azo pigment films composed of pure 4,4‘-2-[ N −(β-hydroxyl)naphthyl]azodiphenyl ( A ) and 4,4‘-2-{ N…
This work focuses on the development of a novel method for molecular level assembly and processing of multilayer azo polymer films. Poly(acrylic acid)-based precursor anilino-functional polymer was first synthesized and used as a polyanion. This polymer was assembled into mono- and multilayer thin films by an electros…
We present an analysis and results on the homogeneous nucleation of a dislocation loop under stress in a perfect crystal. By using a variational boundary integral method in the Peierls-Nabarro framework, we have determined the saddle-point configurations of embryonic dislocation loops and their associated activation e…
Palladium catalysts offer a rich and highly versatile chemistry for the synthesis of novel porphyrins and phthalocyanines. These mild and flexible reactions have been used extensively in the preparation of interesting porphyrins and phthalocyanines, either in the synthesis of substituted precursors or in the modificat…
UNLABELLED: Hydrogenated diamond-like carbon films (DLC, a-C:H), deposited using plasma-assisted or ion beam-assisted techniques, offer great potential as self-lubricating coatings in many tribological applications. Additionally, studies on biocompatibility have shown that DLC is an inert, impervious hydrocarbon with…
Five indole alkaloids, corynantheidine, corynantheine, dihydrocorynantheine, alpha-yohimbine and corynanthine were isolated from bark of Corynanthe pachyceras K. Schum. (Rubiaceae). The structures were established by spectroscopic methods, including previously unreported assignment of all 1H-NMR resonances by COSY and…
Resistance degradation in perovskites generally is assumed to be caused by stoichiometry variations that occur during high field stress. According to this assumption, distinct conductivity profiles should develop during degradation. In this study, microcontact impedance spectroscopy is used to determine the conductivi…
Electrical resistivity, magnetization, and specific-heat measurements on the Heusler-type alloy ${\mathrm{Fe}}_{2}\mathrm{TiSn}$ reveal the occurrence of weak ferromagnetism below 240 K and heavy fermion behavior with a quasiparticle effective mass of $\ensuremath{\sim}40$ times the free electron mass. Ab initio elect…
Polypyrrole (PPy) is of great potential importance due to its excellent conductive properties; however, a major obstacle to commercialization (like many synthetic metals) is its poor stability, especially to oxidation. Here is reported a new synthesis of PPy in the presence of the cobaltabisdicarbollide anion (see Fig…
The aging of water-cooled and moderated nuclear steam supply systems inevitably has given rise to many material corrosion problems of which stress corrosion cracking (SCC) is one of the more insidious. The goal of this paper was to review some of these examples from the author’s experience of interpreting and modeling…
The DBWS program, the latest version of which is 9807a (Young et al., 1999), an upgraded version of DBWS-9411, described by Young et al. (1995), is written in Fortran and can carry out Rietveld re®nements using digitized data (from a neutron or X-ray diffractometer) stored in a text ®le. It also requires an Input Cont…
Various microorganisms were screened for their ability to degrade poly(tetramethylene succinate)-co-(tetramethylene adipate) (PBSA). Strain BS-3, which was newly isolated from a soil sample, was selected as the best strain. From taxonomical studies, the strain was tentatively ascribed to belong to the genus Acidovorax…
Ropes of aligned single-walled carbon nanotubes (SWNTs) up to 10 cm in length (see Figure) have been synthesized here by the hydrogen and argon arc discharge method. The nanotubes are characterized by SEM, TEM, and Raman scattering, and their porosity is investigated. Measurements of the properties of SWNTs can be con…
The excited-state properties, including singlet oxygen quantum yields, of a series of metallotexaphyrins (M-Tex), containing coordinated paramagnetic and also diamagnetic lanthanide(III) and other cations, are reported as are the solution-phase magnetic susceptibilities of the paramagnetic species. It is found that th…
Owing to its importance in understanding the mechanical and thermomechanical behaviours of shape memory alloys (SMAS). the deformation mechanism of martensitic twins has been of continuous research interest. Several deformation steps have been distinguished in accordance with the stress–strain curves, and some explana…