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。
This report deals with space charge behavior in PE (polyethylene) under dc fields. Direct observation of time-dependent space charge profiles in 3-mm thick XLPE (crosslinked low-density polyethylene) cable insulation under dc electric fields was performed using the pulsed electroacoustic method. Stable hetero charges…
Size exclusion chromatography has been performed on micellar aqueous dispersions of soot from an arc discharge experiment to yield chemically unmodified, almost impurity free and size separated multiwall nanotubes.
Several classes of organic magnets based upon the tetracyanoethenide radical anion, [TCNE].–, either unbound, µ, and µ4 bonded to zero, two and four metal sites have been reported. The putative µ4 bonded V(TCNE)x room temperature magnet has been extended to include M(TCNE)x (M = Mn, Fe, Co, Ni) magnets. M for this cla…
The metal-based luminescence of the Eu and Tb complexes of the octadentate ligands L1 and L2a/2b is a function of pH in aqueous solution: in [EuL1], the red-emission is switched on following N-protonation of the sensitising phenanthridine group (pKa = 4.2, pKS1 = 4.4) with a luminescence enhancement of over 500 for λe…
We have previously used Aspergillus nidulans as a fungal model for human phenylalanine catabolism. This model was crucial for our characterization of the human gene involved in alcaptonuria. We use here an identical approach to characterize at the cDNA level the human gene for maleylacetoacetate isomerase (MAAI, EC 5.…
This review article introduces the application of the cholesterol moiety, which has been commonly utilised as a versatile building block in liquid crystals, organic gels and monolayers, to molecular recognition. Effort has especially been made to clarify the characteristics of cholesterol-based assembly systems and th…
Aldol and Knoevenagel condensations were performed with suitably activated Mg–Al hydrotalcite as catalyst in quantitative yields in the liquid phase under mild reaction conditions at a faster rate for the first time.
A primary factor which limits engineering tissues of substantial size is the lack of nutrients readily available to transplanted cells. One potential solution to this nutrient limitation is to encourage the rapid development of a vascular network within three-dimensional tissue engineering matrices. Vascular endotheli…
Melting experiments on fertile peridotite KR4003, a 'pyrolitic' composition, were made from 3 to 7 GPa in piston-cylinder and multi-anvil apparatus. Temperature gradients across the sample were minimized (<25°C), and the compositions of all phases were determined. Modal abundances of coexisting phases were calculated…
The textural and structural properties of high specific surface area (HS) CexZr1-xO2 mixed oxides (CeZrMO) and their modification upon thermal aging have been investigated. Results from BET area determination and complete porosity analysis, as well as high-resolution electron microscopy, XRD, Raman and FTIR spectrosco…
The polydispersity index, the molecular weight distribution (MWD), and the degree of branching ( ) are calculated for hyperbranched polymers obtained in self-condensing vinyl polymerization of AB* monomers in the presence of a core-forming molecule (i.e. a multifunctional initiator, B f *). Two cases are considered: (…
We report the results of high-level quantum-mechanical calculations on the optical transitions of a series of point defects in \ensuremath{\alpha} quartz. We determined all electron-configuration-interaction wave functions for cluster models of the following bulk defects: neutral oxygen vacancy, \ensuremath{\equiv}Si-…
A rapid screening and enrichment method is reported for exploring the size and shape diversities (libraries) of nanometer-scale colloidal particles. With the use of surface-enhanced Raman scattering, a new class of metal nanoparticles has been identified from heterogeneous silver colloids. These particles are relative…
The (110), (111), and (310) surfaces of cubic CeO 2 −ZrO 2 solid solutions have been studied by computer simulation techniques using atomistic models. Surface energies, Ce 4+ /Ce 3+ reduction energies, and penetration profiles of oxygen vacancy formation have been calculated. The results of the calculations suggest so…
Nanocrystalline diamond thin films have been synthesized in an Ar–CH4 microwave discharge, without the addition of molecular hydrogen. X-ray diffraction, transmission electron microscopy, and electron energy loss spectroscopy characterizations show that the films consist of a pure crystalline diamond phase with very s…
Organic materials hold a large promise for second- and third-order nonlinear optical and fast electro-optic applications due to the large nonlinearities of the basic molecular units and the almost purely electronic origin of the nonlinearity. We here discuss the new development in this field with respect to molecules,…
Titanium-containing mesoporous materials, Ti-MCM-41 and Ti-MCM-48, have been successfully modified by trimethylsilylation to exhibit enhanced catalytic activity in the oxidation of alkenes and alkanes with H2O2.
The conductive properties of molecular wires constructed by columnar self-assembly of peripherally substituted large aromatic macrocycles are reported. The Figure illustrates how planar, disc-shaped aromatic molecules form a discotic liquid crystal (LC) phase consisting effectively of coaxially insulated wires of “one…
The possibility of using polysorbate 80-coated polybutylcyanoacrylate nanoparticles to deliver low molecular polar hydrophilic drugs to the CNS has been studied. Tubocurarine (a quaternary ammonium salt) does not penetrate the normal intact blood-brain barrier. However, the injection of this drug directly into the cer…
To further examine the structural and thermodynamic basis of hydrophobic stabilization in proteins, all of the bulky non-polar residues that are buried or largely buried within the core of T4 lysozyme were substituted with alanine. In 25 cases, including eight reported previously, it was possible to determine the crys…