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。
Diamond is a prototype mechanical material. Its hardness is greater than that of any other material. Its shear stiffness is greater than its bulk modulus, and the latter is greater than that of any other material. Its surface energy is greater than that of any other cubic crystal. The purpose of this manuscript is to…
Sm 2 ( Fe 0.95 Cr 0.05 ) 17 N x and Sm2(Fe0.95Mn0.05)17Nx coarse powders 10–70 μm in size were synthesized by crushing mother alloy ingots into 32–74 μm in particle size and subsequent nitrogenation at 748 K in a flowing mixed gas of 60 vol % H2+40 vol % NH3. The effects of Cr or Mn substitution for Fe on the nitrogen…
The magnetic response of MgB2 samples prepared by solid state reaction method, were studied. Important features revealing the granular character of the specimens were verified, as (i) depressed magnetization versus field response, when compared with the corresponding curve for unlinked powder, (ii) the paramagnetic Me…
The dielectric properties, dielectric relaxation behavior, electric conduction and kinetic characteristics of fluorine-containing polysiloxane-imide were investigated. The fluorine-containing polyimide [6FDA + p-PDA] has a low dielectric constant of 3.04, compared to normal polyimides such as Upilex-S [BPDA + p-PDA] w…
The evolution, during laundering, of mechanical, chemical, and morphological prop erties of cellulose fibers covered with a fluorocarbon resin is studied using a combination of low frequency mechanical spectroscopy (LFMS), x-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). From this study of th…
The transport properties of Li-doped NiO and (Li + Ca)-doped NiO were investigated in the high temperature region up to 1073 K. All the oxide samples were prepared by a sol-gel method followed by a sintering procedure. The wet-chemical processing is efficient to prepare oxide ceramics due to shortening of the overall…
Perovskite‐type lanthanum iron oxide (LaFeO 3 ) powders were synthesized by glycothermal reaction at 300°C of a precursor that had been previously prepared by solvothermal decomposition of a mixture of lanthanum(III) isopropoxide and iron(III) butoxide (or methoxide) in toluene. Direct glycothermal reaction of the mix…
Abstract Bis[2-(aminomethyl)pyridine]platinum(II) chloride monohydrate [Pt(amp)2]Cl2·H2O has been found to exhibit photochromism in single-crystalline phase. Single crystals of the chloride were changed from almost colorless to pale-blue by the irradiation of the light. Its aqueous solution, however, shows no photochr…
Case histories of microbiologically influenced corrosion are presented with an emphasis on failure analysis and the techniques for diagnosing the role of fungi in the corrosion. Fungal influenced corrosion has been reported for carbon steel and aluminum fuel tanks; carbon steel cables; and painted and unpainted ship h…
Tunneling magnetoresistance (TMR) and magnetic properties of (Co/sub 50/Fe/sub 50/)/sub x/-(Al/sub 2/O/sub 3/)/sub 1-x/ granular films prepared by dual electron beam evaporation were studied. The influence of the particle size distribution (PSD) on magneto-transport properties is reported. It was found that TMR versus…
The domain pattern evolution in magnetic fields along the diagonal of a square Permalloy film element (edge length 57 /spl mu/m, thickness 207 nm) is studied theoretically and by Kerr-microscopic observation. Equilibrium configurations and magnetization curves are computed using a reduced two-dimensional model, based…
An experiment suitable for a junior–senior-level inorganic synthesis laboratory course is presented. It involves the preparation of nanocrystalline Y 2 O 3:Eu 3+ phosphor using a combustion synthesis technique, and the additional firing of some of the nanoparticles at 900 °C. The particle size of these materials is ca…
The influence of magnesium, phosphorus, and iron additions on the low‐temperature (≤1000°C) sintering of nanocrystalline α‐Al 2 O 3 derived from α‐AlOOH has been investigated. α‐AlOOH powder with a surface area of 50 m 2 /g yielded α‐Al 2 O 3 products with surface areas of 150 and 80 m 2 /g after dehydration at temper…
Synthesis of La/sub 1-x/Sr/sub x/MnO/sub 3/ (x=0.1, 0.2 and 0.3) by homogenous coprecipitation method using urea as precipitant agent is reported. The particles are smaller than 200 nm after heating at 950/spl deg/C. Temperature dependence of the electrical resistivity was found to be similar to the reported value for…
A recently developed Rigaku parallel-beam X-ray diffraction system equipped with a parabolic graded-multilayer mirror in the incident beam and a parallel-slits analyzer in the diffracted beam was used for precision high-temperature diffraction studies. The lattice parameters a and c of α-Al 2 O 3 at room temperature a…
Four new species of Pleurosigma are described from the region of Alexandria in Egypt: P. williamsiisp. nov., P. mariutensissp. nov., P. ramlehensissp. nov. and P. rushdyensissp. nov. The taxa had been previously misidentified as P. rigidum W. Sm., P. elongatum W. Sm., P. speciosum var. sumatricum H. Perag. and P. form…
Abstract [2.2]Paracyclo(3,6)carbazolophane (1a) and [2.2](1,4)naphthaleno(3,6)carbazolophane (1b) were prepared. The structures of 1a and 1b were characterized by 1H NMR. X-ray analysis of 1a revealed that the carbazole ring extremely deviates from the conjugated plane. Electronic spectra of 1a and 1b showed the broad…
This paper reports on the results of crystal chemical analysis and computer simulation of the defect structure of potassium dihydrogen phosphate (KDP) containing impurities of bivalent and trivalent metals. It is shown that these impurities can form defect centers of different types: isolated centers formed by M 3+ an…
Heavily boron-doped nanocrystalline (nc) diamond films were deposited using microwave plasma chemical vapor deposition process in which the growing film surface was continuously bombarded by H+ and hydrocarbon ions. The dependency of grain size and phase purity on the process parameters and boron incorporation was inv…
Abstract The conditions of heat and moisture transport in a car-seat upholstery package are briefly presented, and the necessity of investigation especially of moisture transport is stressed. Three upholstery packages of different furniture covering textiles have been tested with the use of a measuring system for asse…