Stabilization of Time-Varying Linear Discrete Interval-Coefficient Control Systems by Phase State Observations

Stabilization of the trajectories of a linear discrete system closed by dynamic feedback under interval uncertainty of the equations of motion and observation is studied. Sufficient conditions of stabilizability are formulated. Results of numerical experiments are given.     

Special Features of Fracture of Steels from Partially-Alloyed Powders

Special features of fracture of structural steels 45N2D2M and 45N4D2M manufactured by pressing with subsequent sintering from partially alloyed iron powders are studied. Impact bending tests of specimens with different levels of retained porosity show two kinds of fracture, i.e., intraparticle cleavage and interparticle dimple fracture. In addition, the surfaces of the “initial” pores come out to the fracture surface. Other conditions being equal, growth in porosity decreases the proportion of the brittle component of fracture and decreases the critical brittle point.     

入炉煤分炉计量系统的应用探讨

介绍了江西贵溪发电厂的入炉煤分炉计量系统在节能方面开展的一些应用情况。     

Use of Shears with a “Rolling Cut”

This article examines the advantages and disadvantages of using guillotine shears with an inclined top blade for the cross-cutting of flat-rolled products on modern plate mills. It is shown that it is necessary to use shears of an improved design. After shears with a “rolling cut,” designed by the All-Russia Scientific Research, Planning, and Design Institute of Metallurgical Machinery (VNIImetmash), were installed in the line of the 2800 plate mill at the Ural Steel combine, the institute conducted studies to optimize the parameters of the cutting operation and developed recommendations for the shears operators on how to adjust the shears to obtain a quality cut edge on the plates.     

浆砌石坝爆破拆除及监测技术

在陕西宝鸡峡引水枢纽浆砌石大坝改建过程中 ,Ⅱ坝段的全部以及Ⅵ坝段的部分须用爆破方法拆除。为了避免爆破震动对相邻的和保留的浆砌石坝体的不利影响 ,利用伸缩缝和预先开挖的沟槽隔震 ,采用了浅孔爆破分层拆除的方法 ,实施微差爆破 ,严格控制最大一段药量。爆破震动监测和声波测试的结果表明 ,保留的浆砌石坝体没有受到损伤     

基于约束优化的联想记忆模型学习算法

本文提出了一种对称互连神经元网络的学习策略,利用全局约束优化方法确定连接权。优化过程采用了梯度下降技术。这种学习算法可以保证训练样本成为系统的稳定吸引子,并且具有优化意义上的最大吸引域。本文讨论了网络的存储容量,训练样本的渐近稳定性和吸引域大小。计算机实验结果说明了学习算法的优越性。     

Use of sensitivity functions in the problem of designing a multilayer heat shield

An approach is proposed for solving the problem of designing a multilayer heat shield with a prescribed structure from the restrictions on its temperature.Tanslated from Inzhenerno-Fizicheskii Zhurnal, Vol. 61, No. 6, pp. 1014–1018, December, 1991.     

Measurement of the Hardness of Thin Films

A method for evaluating the hardness of coatings with nanosize thickness is suggested. The method includes the determination of the hardness of the “coating-substrate” composition by indenting the coating and subsequent computation of the hardness with the use of the additivity rule. This requires determination of the thickness of the coating, of the hardness of the substrate, and of the indentation depth.     

基于米氏散射及夫朗和费衍射的FAM激光测粒仪

提出了综合运用夫朗和费衍射和米氏散射，即在大粒径范围内采用夫朗和费衍射理论，而在小粒径范围内采用米氏散射理论，来改善小粒径范围内的测量精度，保证激光测粒仪在整个粒径范围内的测量精度。     

Walk－off型光隔离器的隔离度和插入损耗分析

本文介绍了与偏振无关的ｗａｌｋ－ｏｆｆ型光隔离器的原理和结构，从理论和实验两方面分析了影响隔离度和插入损耗的因素，定量计算了加工、调整误差、消光比等对隔离度和插损的限制，给光隔离器的选材、加工和调整提供了依据。