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。
Molecular-crystal precursor states: Molecular dynamics in the nanosecond timescale shows how acetic acid molecules aggregate (see figure for one example) out of a solution in a nonpolar solvent. Is this demixing into a microemulsion the first stage of crystal nucleation?
A new and rapid synthetic method of diaryl carbazone (ArN=NCONHNHAr) from aryl substituted carbazide is reported for the first time. Eight of the compounds were prepared by oxidation of aryl substituted carbazide using N-Bromosuccinimide and pyridine as the oxidation system in good yield under mild condition . This me…
The kinetics equations modified by introducing of the fractional derivatives are used for description of the different dielectric spectra and analysis of the relaxation times temperature dependences. The origin of fractal properties is being discussed in relation with scaling and percolation ideas. The temperature dep…
The properties of porous silicon samples prepared by adding hydrochloric acid to the usual hydrofluoric-acid electrolyte have been studied. These samples exhibit an intense photoluminescence that does not degrade over time and is unaffected by exposure to intense laser illumination. The peak photoluminescence from the…
The influence of the positions of the 1,4-cyclohexenylene fragment and its carbon-carbon double bond in the molecular core, on the mesomorphic behaviour and physical properties of 1,4-disubstituted cyclohexenylene derivatives is discussed and rationalized in terms of existing theories.
Barkhausen pulses generated in stepped motion of a single plane domain boundary (PDB) are investigated experimentally in single-crystalline wafers of the extrinsic ferroelastic ferroelectric gadolinium molybdate containing artificial pinning centers of the “field inhomogeneity” type near the edges of the sample. Two s…
The first part ofthis series discussed current research on yam hairiness testing [Wang 1998]. In this part of the series, the importance of yam hairiness is outlined first. This is followed by a description of recent research on several novel ways of reducing yam hairiness.
Article Type B Semiconductor Photocatalysis: On the Mechanism of the CdS-Catalyzed Linear Photoaddition of 2,5-Dihydrofuran to Azobenzene was published on February 1, 1999 in the journal Zeitschrift für Physikalische Chemie (volume 213, issue 2).
High-frame-rate neutron radiography is used to observe the behavior of a high-temperature (≤773 K) molten Pb-Bi alloy dropped into a vessel that contains water. Experiments are also performed with an empty vessel. Using high-speed cameras combined with image intensifiers and a high-flux neutron source, the interaction…
Based on an original design by F. H. Attix, an improved free-air ionization chamber was constructed at the National Radiation Standard Laboratory of the Institute of Nuclear Energy Research (INER, Taiwan), as the primary standard for x-rays generated at energy levels between 50 keV and 300 keV. Various improvements we…
By means of a sol–gel method, we prepare layered-perovskite samples of La2—2xCa1+2xMn2O7 (x = 0.3) at synthesis temperatures from 1000 to 1200 °C. The grain size changes from 20 to 45 nm. A magnetoresistance above 25% at low temperatures is acquired in a field of 0.8 T. We also find that decreasing grain size is deter…
Results of DC electrochemical measurements of four Ni‐base alloys are presented. The tests were conducted in 1 percent sulphuric acid, containing 0.2 percent chlorides at temperature 353K. Gravimetric test, performed in the same conditions, revealed excellent properties of alloy signed A3. Pitting corrosion of alloy A…
We report first-principle electronic structure calculations of the three representative minerals of the platinum group: cooperite (PtS), braggite (PdPt3S4) and sperrylite (PtAs2) using the Tight-Binding Linear Muffin Tin Orbital (TB-LMTO) technique. We predict non-metallic behaviour for all three minerals with semicon…
The paper deals with the detail investigation of the smooth motion of the single plane domain wall (PDW) in the vicinity of the initial/steady position and analysis of the mechanisms of Barkhausen noise generation during PDW jump-like motion.
Interest in the study of the dynamic properties of materials subjected to high-rate loading has been motivated by two circumstances. First, the design of structures and evaluation of technological processes require a correct consideration of the properties of the material to be used. Second, the study of the macroscop…
The creep behavior of three types of silicon carbide fibers that have been fabricated via chemical vapor deposition is described. The fibers exhibit only primary creep over the range of conditions studied (1200°–1400°C, 190–500 MPa). A transmission electron microscopy study of the microstructural development that is i…
Nano-grain sized β-SiC was prepared with various additives by hot-pressing in Ar. The relative bulk densities were more than 95 %. As-sintered bodies were composed of equiaxed grains. Amorphous phase existed at grain boundaries in each as-sintered material. Tension tests were performed at the initial strain rates from…
This study reports the influence of preforming on the final thickness distribution of superplastically formed domes. It is very common to see about 50% thickness difference between apex and periphery of domes formed from initially uniform blanks. If the initial shape of the blank is modified properly by preforming, th…
We show that the layer groups, describing the symmetry of compatible (coherent, permissible) ferroelastic domain walls, are polar. From this it follows that all compatible ferroelastic walls in dielectric crystals can be spontaneously polarized. We shortly discuss the feasibility of reversing the spontaneous polarizat…
Eu-and Ce-Eu-containing quartz glasses obtained by a direct sol-gel-glass transition are investigated. It is discovered that the conversion of a xerogel into a glass leads to lowering of the symmetry of the Eu3+ optical centers from hexagonal to orthorhombic and a many-fold increase in the efficiency of the excitation…