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。
Abstract The chemistry of polyhedral oligomeric silsesquioxanes (POSS) has taken a tremendous leap over the past decade. New synthetic approaches have been developed, and new complexes based on elements throughout the periodic table have been synthesized and applied in catalytic processes such as alkene epoxidation, O…
A short synopsis of the recently proposed reptation models based on the Doi and Edwards’ tube concept is provided. Specifically, a critical examination of a number of theories like the “simplified” Mead-Larson-Doi model, the Öttinger model and the “Double Convection Reptation” model of Marrucci and coworkers has been…
A creeping squeeze flow apparatus [1 - 2] was modified with a Fizeau interferometer optical motion transducer and equipped with a high-temperature, high-vacuum enclosure. Long-term squeeze flow experiments were done on a broad-MW, 1 melt-flow index commercial HDPE at 190˚C, with runs covering about a week. Over this p…
DOAJ is a unique and extensive index of diverse open access journals from around the world, driven by a growing community, committed to ensuring quality content is freely available online for everyone.
It is shown that the combined use of a mesoscopic lattice Boltzmann solver with finite-volume techniques, both enriched with local-refinement (multiscale) capabilities, permits to describe transport phenomena at fluid-solid interfaces to a degree of detail which may help dispensing with empirical correlations.
Recycled plastics are considered as materials with physical, mechanical and aesthetic properties worse than the virgin ones. In fact, this is true because degradation during lifetime and during the recycling operations changes the structure and the morphology of the polymers and then the final properties of the second…
This overview provides an illustrated, comprehensive survey of some commonly observed protein-fold families and structural motifs, chosen for their functional significance. It opens with descriptions and definitions of the various elements of protein structure and associated terminology. Following is an introduction i…
The work in this article is part of a project to develop a quantitative description of stress corrosion cracking (SCC) on the secondary side of pressurized water reactor (PWR) steam generator tubing based on existing information from operating plants and from laboratory experiments. This work is the second step in dev…
Spark plasma sintering (SPS) method was used to obtain dense NASICON ceramics with a high‐electrical conductivity, which was compared with conventional solid‐state sintering. The fully dense NASICON was achieved at a relatively low‐sintering temperature of 1100°C, whereas the apparent density of the specimen prepared…
Abstract A “sandwich” type polyoxometalate, Na 12 [(WZn 3 (H 2 O) 2 ][(ZnW 9 O 34 ) 2 ], was used as an oxidation catalyst in aqueous biphasic reaction media to effect oxidation of alcohols, diols, pyridine derivatives, amines and aniline derivatives with hydrogen peroxide. The catalyst was shown by 183 W NMR to be st…
Abstract Summary: Thermogravimetry and differential scanning calorimetry have been used to study the thermal and thermo‐oxidative degradation of polystyrene (PS) and a PS–clay nanocomposite. An advanced isoconversional method has been applied for kinetic analysis. Introduction of the clay phase increases the activatio…
Abstract Summary: If long polyelectrolyte chains are attached densely to colloidal latex particles, a spherical polyelectrolyte brush results. These spherical polyelectrolytes are dispersed in water and carry a high charge. We demonstrate that these systems can be used to immobilize ions of heavy metals, such as gold,…
Polycrystalline Na2W2O7 (anhydrous) was prepared by a solid-state reaction technique. The formation of the compound has been confirmed by X-ray powder diffraction studies and Raman spectroscopy. The unit cell structure of the material has been found to be orthorhombic of the Cmca space group. Complex impedance analysi…
Various glass‐ceramics were prepared based on the BaO–Al 2 O 3 –B 2 O 3 –SiO 2 system with the addition of La 2 O 3 , ZrO 2 , or NiO in an attempt to develop a suitable sealant for planar solid‐oxide fuel cells operating at 800°C. To estimate the applicability of these glasses as suitable sealants, their thermal and c…
Abstract The fabrication of single‐walled carbon nanotube (CNT) fibers containing (salmon) DNA has been demonstrated. The DNA material has been found to be adequate for dispersing relatively large concentrations (up to 1 % by weight) of carbon nanotubes. These dispersions are better suited for fiber spinning than prev…
This paper reports on an investigation into the space charge formation and decay at different material interfaces. In particular, the influence of the interface between electrode and polymer or polymer and polymer on the space charge dynamics has been studied. Planar samples were subjected to high DC electric stresses…
The wave function of a hole bound to an individual Mn acceptor in GaAs is spatially mapped by scanning tunneling microscopy at room temperature and an anisotropic, cross-like shape is observed. The spatial structure is compared with that from an envelope-function, effective mass model, and from a tight-binding model.…
We have investigated the local atomic structure of an amorphous Co$_{57}$Ti$_{43}$ alloy produced by Mechanical Alloying by means of x-ray diffraction and EXAFS analyses on Co and Ti K-edges. Coordination numbers and interatomic distances where found and compared with those determined using an additive hard sphere (AH…