Noise–Power Optimization of Incremental Data Converters

Incremental data converters (IDCs) are useful in instrumentation and measurement applications, where low-frequency analog signals need to be converted into digital form with high accuracy and low power dissipation. They are particularly well suited for applications where a single analog-digital converter is multiplexed between many channels. This paper proposes an exact design methodology for IDCs, which optimizes the signal-to-noise ratio of the converter under practical design constraints. The process also allows the designer to apportion the noise budget in an arbitrary manner between thermal and quantization noise. The design process is illustrated by an example which describes the optimization of a third-order multiplexed IDC.     

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.     

富氧燃烧技术在梭式窑中的应用

研究了富氧燃烧技术对梭式窑烧成的影响.研究结果表明,随着氧浓度从21%-30%的逐渐增加,CO总浓度和NO总浓度都先明显下降,后缓慢上升;节能效果在初始段较为明显,而后效果不明显;而实际烟气量与氧浓度成反比,与过剩空气系数成正比.     

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.     

调整水量法(代用法)测定水泥标准稠度用水量方法的改进

结合兰州市的水泥标准稠度用水量方法测定 (代用法 )的实例 ,分析代用法测定标准稠度用水量的缺点 ,并对此方法提出了一些改进措施     

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.