Experience with Siberian Centralized Dispatch Regulation regarding location determination of damages sustained by intersystem high-voltage transmission lines

A set of measures that can be implemented by the Relay-Protection and Automated-Equipment Service for Centralized Dispatch Regulation (CDR) in Siberia to determine the location of damage sustained by inter-system 550-and 220-kV transmission lines maintained by the United Power System (UPS) of Siberia, and the methodology and technology of damage-location determination (DLD) are described. The damage sustained by the 500-kV high-voltage lines (HL), and the accuracy of DLD relative to zero-sequence emergency parameters are analyzed statically. __________ Translated from élektricheskie Stantsii, No. 5, pp. 59–62, May, 2006.     

双程放大技术在光纤放大器中的应用

双程放大技术是一种高效率、低成本的实用化放大技术。本文介绍了双程放大技术的优点及在各种放大器中的应用。     

Zero bias anomalies of transport characteristics of single-barrier GaAs/AlAs/GaAs heterostructures as a result of resonance tunneling between parallel two-dimensional electron gases and suppression of resonance tunneling in a magnetic field as a manifestation of the Coulomb gap in the tunnel density of states

Electron tunnel transport across single-barrier GaAs/AlAs/GaAs heterostructures is investigated. It is shown that “zero bias anomalies”—extrema in differential conductivity close to the zero bias—in the structures investigated are caused by resonance tunneling between parallel two-dimensional electron gases in enriched layers, which are formed from both sides of the barriers due to the presence of Si donor impurities in barriers. The suppression of resonance tunneling between parallel two-dimensional electron gases is found in narrow ranges close to the zero bias (tunnel gap) in a strong magnetic field parallel to the current direction only when a single Landau level is occupied for each of the two-dimensional electron gases. Suppression is induced by a Coulomb gap at the Fermi level in the tunnel density of states. This experiment originally revealed the manifestation of a Coulomb gap in tunneling between parallel two-dimensional electron gases with relatively low mobilities. For these electron gases, the influence of disorder or random potential fluctuations on the mechanism of formation of the tunnel gap is noticeable.     

Simulation of Economic Dynamics under Ecological Balance Conditions

A model of economic dynamics under stable ecological balance conditions is proposed. A methodology of construction of an optimal growth path is constructed for this model.     

栅板注射模设计

分析了栅板零件的工艺性 ,介绍了栅板注射模的设计方案及设计要点 ,并对浇注系统的设计计算作了较详细的阐述。该模具经生产验证 ,各部件动作灵活、可靠 ,生产的塑件质量符合要求。     

丙烯酸酯与甲基丙烯酸酯的共聚及性能研究

采用悬浮聚合法，以丙烯酸－２－乙基－己酯与甲基丙烯酸十二酯为单体，合成了共聚型高吸油性树脂。研究了共聚单体的配比、交联剂用量、引发剂用量诸因素对高吸油性树脂的性能影响。制得的树脂可以吸其自身质量的１１．８倍的煤油、１４．７倍的苯、６．５倍的泵油。     

变速切削系统振动频率的变化特征

本文主要讨论变速切削系统中颤振频率随机床主轴转速变化的规律。理论分析和试验结果都证明在变速切削中颤振频率随转速呈分段线性锯齿状变化。试验在立式铣床和普通车床上进行。     

Electromechanical Conversions in Composite Dielectric Materials During Complex Thermomechanical Excitation

It is shown that the degree of the stress-strain state created by temperature field can be estimated by using the electromechanical conversion phenomenon. It is established that the electromagnetic response to impact excitation of composite materials is a structure-sensitive characteristic.