Materials Literature

文献浏览

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。

清除
第 226490 / 229271 页 · 当前展示 4,529,781–4,529,800 / 4,585,419 条匹配结果 · 摘要仅作预览

New properties of Bacillus subtilis succinate dehydrogenase altered at the active site. The apparent active site thiol of succinate oxidoreductases is dispensable for succinate oxidation

Lars Hederstedt、L O Hedén1989-06-01Biochemical Journal

Mammalian and Escherichia coli succinate dehydrogenase (SDH) and E. coli fumarate reductase apparently contain an essential cysteine residue at the active site, as shown by substrate-protectable inactivation with thiol-specific reagents. Bacillus subtilis SDH was found to be resistant to this type of reagent and conta…

Bacterial Genetics and BiotechnologyEndoplasmic Reticulum Stress and DiseaseEnzyme Structure and Function

CHROMOSOME NUMBERS IN DIATOMS: A REVIEW

John Patrick Kociolek、Eugene F. Stoermer1989-06-01Diatom Research

Previously published observations on chromosome numbers for 43 diatom taxa are reviewed. Members of five centric families, as well as araphid, monoraphid and biraphid pennate species are included in the list. Greatest range in diploid complement is found in the biraphid group, where the smallest (8) and largest (130)…

Diatoms and Algae Research

Polycyclic Aromatic Hydrocarbon (PAH) Residues on Skin in Relation to Air Levels among Roofers

Mary S. Wolff、Robin Herbert、Michele Marcus 等 6 位作者1989-06-01Archives of Environmental Health An International Journal

To assess the utility of skin wipes as an index of exposure to polycyclic aromatic hydrocarbons (PAHs), simultaneous skin wipe and breathing zone air samples were obtained for 10 roofers. Samples were obtained during removal of an old coal-tar pitch roof and application of a new asphalt roof. Skin wipes were obtained…

Textile materials and evaluations

Effect of temperature and molecular weight on enthalpy relaxation in polystyrene

A.K. Agrawal1989-06-01Journal of Polymer Science Part B Polymer Physics

Abstract Isothermal enthalpy relaxation in polystyrene was measured as a function of temperature and molecular weight on a differential scanning calorimeter. Relaxation spectra were derived from the data and expressed as a distribution of relaxation times. For a given molecular weight the relaxation spectra at differe…

Polymer crystallization and propertiesMaterial Dynamics and PropertiesPolymer Nanocomposites and Properties

A photoelectrochemical investigation of the n- and p-type semiconducting behaviour of copper(I) oxide films

W. Siripala、K. P. Kumara1989-06-01Semiconductor Science and Technology

Copper(I) oxide films were prepared on copper substrates by exposing them to solutions containing Cu 2+ ions, and it was observed that the photoresponse of these films electrodes in a photoelectrochemical cell is both n- and p-type. However, it was observed that the n-type behaviour of these film electrodes could be e…

Iron oxide chemistry and applicationsCopper-based nanomaterials and applicationsElectronic and Structural Properties of Oxides

Testing a mechanistic model. IX. Competition between anions for sorption by soil

N. J. Barrow1989-06-01Journal of Soil Science

SUMMARY A model which describes the reaction of anions and cations with soil when they are added separately was applied to the results of Roy et al. (1986a,b ) in which pair‐wise combinations of phosphate, arsenate, and molybdate competed for sorption on three soils. The model postulates that the reaction is between i…

Groundwater and Isotope GeochemistryClay minerals and soil interactionsIron oxide chemistry and applications

Thermal degradation processes in aliphatic polydithiocarbonates

Giorgio Montaudo、Concetto Puglisi、Corrado Berti 等 5 位作者1989-06-01Journal of Polymer Science Part A Polymer Chemistry

Abstract The thermal degradation of three aliphatic polythiocarbonates was investigated by direct pyrolysis in the ion source of a mass spectrometer operating both in electron and chemical ionization modes. The overall evidence indicates that these polymers start decomposing at about 250–280°C by an end‐biting process…

Thermal and Kinetic AnalysisAntimicrobial agents and applicationsEnvironmental Chemistry and Analysis

Off-resonance contributions to acoustical bubble spectra

Kerry W. Commander、Elan Moritz1989-06-01The Journal of the Acoustical Society of America

Comparisons of experimental optical and acoustical bubble size spectra disagree in size distribution at the low end of the spectrum. Previous methods of obtaining acoustic bubble size information relied strictly on resonant acoustical scattering and absorption theory. For some plausible distributions, these traditiona…

Fluid Dynamics and MixingUltrasound and Cavitation PhenomenaPhotoacoustic and Ultrasonic Imaging

Measuring and Interpreting Low-Stress Fabric Mechanical and Surface Properties

R.C. Dhingra、D. Liu、R. Postle1989-06-01Textile Research Journal

The concept of using engineering principles as an aid in designing textile fabrics with desirable aesthetic characteristics is further developed. Fundamental to this ap proach is the measurement of fabric mechanical and surface properties, e.g., fabric tensile, shear, bending, surface, and lateral compression properti…

Dyeing and Modifying Textile FibersTextile materials and evaluationsColor Science and Applications

Arylidene Polymers IV. Synthesis, Characterization and Morphology of New Polyesters of Diarylidenecyclohexanone

Mahmoud A. Abdalla、Kamal I. Aly、A. S. HAMMAM1989-06-01High Performance Polymers

New polyesters prepared by the intefacial polycondensation of 2,6-bis(4- hydroxybenzylidene ) cyclohexanone (I) and 2,6-bis(4-hydroxy-3-methoxybenzylidene)- cyclohexanone (II) with 4,4'-diphenic, isophthalolyl, terephthaloyl, adipoyl and sebacoyl dichlorides have been produced. The yield and the values of reduced visc…

Synthesis and Properties of Aromatic CompoundsInorganic and Organometallic ChemistrySynthesis and properties of polymers

An X-Ray Diffraction Study on the Structure of Solvated Cadmium(II) Ion and Tetrathiocyanatocadmate(II) Complex in N,N-Dimethylformamide

Kazuhiko Ozutsumi、Toshiyuki Takamuku、Shin‐ichi Ishiguro 等 4 位作者1989-06-01Bulletin of the Chemical Society of Japan

Abstract The structure of solvated cadmium(II) ion and the tetrathiocyanatocadmate(II) complex in N,N-dimethylformamide (DMF) has been determined by means of X-ray diffraction at 25 °C. The radial distribution curve for a cadmium(II) perchlorate DMF solution is well explained in terms of the presence of the octahedral…

Crystal structures of chemical compoundsLanthanide and Transition Metal ComplexesChemical and Physical Properties in Aqueous Solutions

Improved Dielectric Properties for Anodic Aluminum Oxide Films by Soft/Hard Two‐Step Electrolytic Anodization

John R. Dickey、J.L. Davidson、Yonhua Tzeng1989-06-01Journal of The Electrochemical Society

A two‐step electrolytic anodization process, denoted as the "soft/hard" process, has been studied as a means of fabricating a high quality dielectric. A layer of porous (soft) anodized aluminum followed by boric acid barrier (hard) anodization produced a dense amorphous aluminum oxide with excellent dielectric propert…

Semiconductor materials and devicesOptical Coatings and GratingsAnodic Oxide Films and Nanostructures

Charge Carrier Transport Properties of Organopolysilanes and Their Application to Xerographic Photoreceptor

Kenji Yokoyama、Masaaki Yokoyama1989-06-01Chemistry Letters

Abstract Aiming application of the high hole drift mobility in organopolysilanes, the organopolysilane-based organic layered photoreceptors for electrophotography have been developed with phthalocyanine pigments as a photo-generating material. The photoreceptor combined with titanylphthalocyanine exhibited the high se…

Phase-change materials and chalcogenidesAdvanced Chemical Sensor TechnologiesSolid-state spectroscopy and crystallography

Combined Electrochemical and Radiotracer Study on the Ionic Charge Transport Coupled to Electron Transfer and Ionic Equilibria in Electroactive Polymer Films on Electrodes

György Inzelt、György Horányi1989-06-01Journal of The Electrochemical Society

A combination of electrochemical and radiotracer methods offers a unique possibility of studying the motion of counter‐ and co‐ions during electrochemical transformations occurring in a polymer film. In addition, information can be obtained about the embedding of electrolytes during electropolymerization penetration o…

Fuel Cells and Related MaterialsConducting polymers and applicationsAnalytical Chemistry and Sensors

Ferroelectric‐Domain Structure in Piezoelectric Ceramics

P.G. Lucuta1989-06-01Journal of the American Ceramic Society

Twin‐related (tetragonal (T), rhombohedral (R)) adjacent ferroelectric domains, which require a smaller energy for the rotation of the polarization vector, have been found to occur in lead zirconate titanate type piezoceramics at the morphotropicphase boundary, explaining the triplet splitting observed in electron dif…

Ferroelectric and Piezoelectric MaterialsMultiferroics and related materialsAcoustic Wave Resonator Technologies

Electrostatic properties of L-alanine from x-ray diffraction at 23 K and ab initio calculations

R. Destro、R. M. Bianchi、Gabriele Morosi1989-06-01The Journal of Physical Chemistry

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectrostatic properties of L-alanine from x-ray diffraction at 23 K and ab initio calculationsRiccardo Destro, Riccardo Bianchi, and Gabriele MorosiCite this: J. Phys. Chem. 1989, 93, 11, 4447–4457Publication Date (Print):June 1, 1989Publication History Published online1 Ma…

Crystallography and molecular interactionsChemical and Physical Properties in Aqueous SolutionsX-ray Diffraction in Crystallography

Nonreciprocal operation of structures comprising a section of coupled ferrite lines with longitudinal magnetization

J. Mazur、Michał Mrozowski1989-06-01IEEE Transactions on Microwave Theory and Techniques

Nonreciprocal devices based on a section of two coupled lines containing ferrite magnetized in the propagation direction are investigated. The necessary conditions for nonreciprocal operation are derived. Several configurations are proposed and their scattering matrices are given. An explanation of the action of exper…

Electromagnetic Scattering and AnalysisMagnetic Properties and ApplicationsElectromagnetic Simulation and Numerical Methods

Meiosis, nuclear cyclosis, and auxospore formation inNavicula sensu stricto(Bacillariophyta)

David G. Mann、Alan J. Stickle1989-06-01British Phycological Journal

The sexual reproduction of Navicula oblonga is described. Cells aggregate actively and lie side-by-side, touching each other as they enter meiotic prophase. In contrast to some other species traditionally included in Navicula, the gametangia do not subsequently separate and no copulation envelope is produced. Each gam…

Aquatic Ecosystems and Phytoplankton DynamicsProtist diversity and phylogenyDiatoms and Algae Research

Thermooxidation yellowing of aliphatic polyamides

Dominique Fromageot、Agnès Roger、Jaques Lemaire1989-06-01Die Angewandte Makromolekulare Chemie

Abstract During the thermo‐oxidation at 90°C of unsubstituted or N‐substituted aliphatic polyamides, formation of products which absorb in the UV and visible regions is observed. These products are photo‐instable either at short wavelengths or at long wavelengths and their photo‐reactivity is wavelength dependent. The…

Epoxy Resin Curing ProcessesSynthesis and properties of polymersPhotopolymerization techniques and applications

Description of a nematic liquid crystal based on the phthalocyanine subunit

Dominique Lelièvre、M. Petit、J. Simon1989-06-01Liquid Crystals

Octasubstituted phthalocyanine derivatives have been synthesized and characterized. The mesophases were studied by optical microscopy, differential scanning calorimetry and small angle X-ray diffraction. For the 2-ethyl-hexyloxy-derivative, three transitions are observed at 170°C, 223°C and 270°C. In the latter temper…

Liquid Crystal Research AdvancementsSurfactants and Colloidal SystemsPorphyrin and Phthalocyanine Chemistry