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 electrical noise characteristics of single-walled carbon nanotubes have been investigated. For all three cases of individual isolated nanotubes, thin films of interconnected nanotubes, and bulk nanotube mats, anomalously large bias-dependent 1/f noise is found. The noise magnitude greatly exceeds that commonly obs…
There are two classes of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase: the class I enzymes of eukaryotes and some archaea, and the class II enzymes of certain eubacteria. The activity of the class I Syrian hamster HMG-CoA reductase is regulated by phosphorylation-dephosphorylation of Ser871. Phosphorylati…
The preparation of β-SiC/MC (M = Ti, Nb, and Ta) nanocomposite ceramics by the pyrolysis under an inert atmosphere of precursors consisting in interpenetrating networks of poly[(dimethylsilylene)diacetylene], 1, and polymeric metal oxide is described. The precursors are obtained by in-situ precipitation of the desired…
Carbon single-wall nanotubes (SWNTs) are of great interest because of their expected novel electronic, mechanical, and adsorption properties. However, to test these properties and develop applications, it is necessary to isolate large aligned nanotube bundles. Here we demonstrate that SWNT samples may be converted fro…
ADVERTISEMENT RETURN TO ISSUEPREVNoteNEXTA New Method for the Synthesis of Tri-tert-butyl Diethylenetriaminepentaacetic Acid and Its DerivativesSamuel Achilefu, R. Randy Wilhelm, Hermo N. Jimenez, Michelle A. Schmidt, and Ananth SrinivasanView Author Information Discovery Research, Mallinckrodt, Inc., St. Louis, Misso…
Ultrathin cross sections of core−corona polymeric nanospheres, which were prepared by the free-radical polymerization of methacrylate-terminated poly(ethylene glycol) (MA-PEG) as a hydrophilic macromonomer and styrene (St) as a hydrophobic comonomer in a ethanol/water (4/1, v/v) mixed solvent, were observed by using t…
The notion of using support materials to achieve high dispersions of metal particles has been extended to the synthesis of carbon nanofibers from the catalyzed decomposition of ethylene. By using this approach it has been possible to generate nanofibers whose widths are dictated by the dimensions of the supported meta…
Solidlike and liquidlike linear viscoelastic responses were observed at low and high temperatures ( T ) for polystyrene−polyisoprene−polystyrene (SIS) triblock copolymers dissolved in an I-selective solvent, n -tetradecane (C14). These SIS systems behaved as thermoreversible physical gels, with the microphase-separate…
Surface and interface play an important role in controlling the properties of a broad range of materials. With the recent development of various advanced surface analytical techniques, our understanding of material surfaces and interfaces has been significantly increased, as with our ability to control and even to tai…
The alternating copolymer of alkyl sorbates with oxygen was prepared by photopolymerization or thermal polymerization in the presence of oxygen. Methyl sorbate provided an alternating copolymer with oxygen on exposure to sunlight at room temperature. The yield and molecular weight of the obtained polymers depended on…
Raman spectra of oriented alpha-helical protein molecules exhibit a prominent band near 1340-1345 cm(-)(1), the intensity of which is highly sensitive to molecular orientation. Polarization of the 1340-1345 cm(-)(1) marker is evident in Raman spectra of alpha-helical poly-L-alanine (alphaPLA) and alpha-helical poly-ga…
We present inelastic neutron scattering (INS) experiments on various types of cellulose revealing the universal nature of the disordered regions from the point of view of low-energy dynamics. Using INS in combination with the deuteration of polar groups technique, we have studied the dynamic response of hydroxyl group…
The excess polarizability volumes, Δ V p, of the relaxed S 1 and T 1 excited states of several covalently bridged zinc porphyrin dimers and their corresponding monomers have been measured using the flash photolysis time-resolved microwave conductivity technique. Δ V p (S 1 ) increases from close to zero for a diaryl-s…
The structure of asymmetric poly(styrene- b -2-vinylpyridine) (PS-PVP) diblock copolymers allowed to order in a thin film is observed by a combination of secondary ion mass spectrometry and scanning force microscopy. The surface/interface-induced ordering persists over a surprisingly long range (more than 1 μm). The 2…
Poly(vinylidene fluoride) (PVDF) fibers spun at different take-up speeds (10.6−61.0 m/min) were subjected to stretch−hold deformation at room temperature and in-situ simultaneous synchrotron small- and wide-angle X-ray scattering measurements. Crystal transformation from α to β form and morphological changes in lamell…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTManipulation of Surface Properties by Patterning of Covalently Bound Polymer BrushesMarc Husemann, Michael Morrison, Didier Benoit, Jane Frommer, C. Mathew Mate, William D. Hinsberg, James L. Hedrick, and Craig J. HawkerView Author Information Center for Polymeric Inte…
The Soret band for porphyrins is usually observed in the near-ultraviolet at approximately 400 nm, and few examples of "nonexpanded" porphyrins with this major absorption band at values above 500 nm have previously been reported in the literature. Ring fusion with aromatic ring systems such as naphthalene, anthracene,…
We consider ferroelectric phase transitions in both short-circuited and biased ferroelectric-semiconductor films with a space (depletion) charge which leads to some unusual behavior. It is shown that in the presence of the charge the polarization separates into `switchable' and `non-switchable' parts. The electric fie…
True stress−strain curves measured during uniaxial tensile deformations of polyethylene generally show four characteristic points where the differential compliance and the recovery properties change. They can be associated with the onset of isolated inter- and intralamellar slip processes (point A), a change into a co…
A novel route to form superhydrophobic−superhydrophilic micropatterned coating film has been developed. UV light was irradiated on the superhydrophobic coating film which consists of three layers, a flowerlike Al2O3 gel film, a very thin TiO2 gel layer, and a FAS layer, to cleave the fluoroalkyl chain in FAS selective…