ADI-FDTD Method With Fourth Order Accuracy in Time

This letter presents an unconditionally stable alternating direction implicit finite-difference time-domain (ADI-FDTD) method with fourth order accuracy in time. Analytical proof of unconditional stability and detailed analysis of numerical dispersion are presented. Compared to second order ADI-FDTD and six-steps SS-FDTD, the fourth order ADI-FDTD generally achieves lower phase velocity error for sufficiently fine mesh. Using finer mesh gridding also reduces the phase velocity error floor, which dictates the accuracy limit due to spatial discretization errors when the time step size is reduced further.     

Comparative Study of Rubidium and Cesium as Promoters in Carbon-supported Ruthenium Catalysts for Ammonia Synthesis

Sibunit-supported Ru-catalysts promoted with cesium or rubidium compounds have been comparatively studied with XPS. The cesium promoter interacts both with support and with active component. The absence of the promoter–support interaction in the case of rubidium provides a stronger interaction between promoter and active component compared to the cesium-based catalysts. These differences in the promoter–support and promoter–metal interactions are exhibited when a sequence of ruthenium and alkali introduction are changed.     

Thermal solution of Kashpir shale in pressurized benzene under supercritical conditions

The results of the thermal solution of oil shale in benzene in a flow unit under supercritical conditions are reported. It was found that the conversion of shale organic matter into liquid products increased by a factor of 2.5 with an increase in the solvent pressure from 5 to 15 MPa.     

Model of the magmatic thermolysis of coal matter deep in the earth (short communication)

A model of contact thermolysis was constructed based on a combined set of equations for heat transfer from a magmatic intrusion to a coal bed and the kinetics of thermal coal conversion. This model was illustrated by the generation of petroleum hydrocarbons deep in the earth by the thermolysis of the sapropelic matter of boghead.     

Kinetics of concentrating and ultrapurifying dichlorosilane by batch distillation with periodical withdrawals

The results of theoretical and experimental studies for the kinetics of separating dichlorosilane from a mixture of volatile chlorosilanes and ultrapurifying the dichlorosilane concentrate by batch distillation are reported. A mathematical model of the process is proposed. It is shown that the model and computational algorithm adequately describe both processes. The obtained experimental and theoretical data made it possible to design a concentration and ultrapurification process with a maximal productivity at a specified product purity.     

Properties of impregnants from shale phenols

Impregnants prepared from shale phenols for cellular materials had a cohesive strength of 2.4–18.5 J/m² and a specific elongation of 160–170%. The adhesive strength toward a metal was 3.5–6.0 J/m²; in the case of concrete, it was greater than the concrete strength.     

Corundum concretes based on modified phosphate-containing binders

Physicotechnical properties are provided for concretes based on mechanically-activated phosphate suspensions previously modified with magnesium and aluminum hydroxides and silicic acid. The results obtained demonstrate the efficiency of using modifying additions in order to increase the strength and heat resistance of corundum concretes. Translated from Novye Ogneupory, No. 5, pp. 32–35, May 2008.     

单环氧背面漆在八钢彩涂机组生产中存在的问题及解决方案

对八钢彩涂机组生产中单环氧背面漆的应用进行了分析,介绍了实际生产中使用单环氧背面漆存在的问题,并制定出相应解决措施及方案,确保彩涂单环氧背面漆的表面质量及机械性能的要求.     

Serviceability of glass and glassware (review)

Research on the properties and characteristics of glass that determine the serviceability of the most massive glass objects and glassware is reviewed. The theoretical assumptions, general questions concerning the strength, chemical resistance (corrosion), and spectral characteristics of glass are noted. The properties and characteristics indicated are examined for sheet glass, glass fiber, and glassware.     

Stability of hydrogenated nanodiamonds under extreme ultraviolet irradiation

It is generally accepted that diamond is resistant to a wide spectrum of electromagnetic radiation from the ultraviolet through to the soft X-ray range, which makes it very attractive for the fabrication of diamond-based photodetectors. However the effect of photon radiation on the diamond structure has not yet been examined. In the work presented here, photoelectron spectroscopy has been used to study the graphitization of nanodiamond crystallites exposed to extreme ultraviolet radiation. Under such irradiation, the surface hydrogen groups and graphite species are found to prevent graphitization. The mechanism of radiation-induced nanodiamond graphitization is discussed.