太钢3号卷取机TDC控制系统开发与应用

太钢热连轧厂3号卷取机改造前所采用的美国西屋公司WDPF控制系统已不能满足目前生产和质量的要求，进而应用西门子公司的TDC控制系统对其进行了改造。该项目的设计、编程、调试由太钢自行完成，改造中采用了带钢头部张力优化控制、夹送辊张力控制、卷取机平滑曲线减张控制、卸卷小车横移极限升降极限模拟控制等多项新技术。其改造后产品产量、综合成卷率和卷形良好率均明显提高。     

离子液体催化C_5馏分中二烯烃的聚合反应

合成了多种基于1-丁基-3-甲基咪唑阳离子的离子液体,并作为裂解C5馏分中混合二烯烃聚合反应的介质。考察了离子液体种类、反应温度、反应时间和添加Lew is酸对混合二烯烃聚合反应的影响。实验结果表明,以硝酸根为阴离子的离子液体对混合二烯烃的聚合反应具有一定的阻聚作用;以六氟磷酸根为阴离子的离子液体能明显促进混合二烯烃的聚合反应,提高二聚物的含量;添加Lew is酸(质量分数为1%的ZnCl2)的离子液体对混合二烯烃的聚合反应具有更明显的促进作用,其效果仅次于酸性氯铝酸类离子液体,反应温度以30℃以下为宜,温度过高将促使二聚物进一步聚合,形成三聚物乃至多聚物,降低二聚物的含量。     

Effect of the particle size ratio on the conductivity of conductor-insulator powder composites: Numerical simulation

A theoretical method for determining the percolation limit and effective conductivity of composites based on polydisperse mixtures of insulator and conductor powders is proposed. The effect of the particle size ratio between the insulator and conductor on the percolation limit and effective conductivity is studied. Numerical simulation of the microstructure, effective properties, and percolation limit in composites is discussed. __________ Translated from Poroshkovaya Metallurgiya, Vol. 46, No. 1–2(453), pp. 31–40, 2007.     

Comparative study on adaptive rational macromodels of highly resonant structures

Two macromodeling techniques using rational bases are investigated to accurately predict the natural frequencies of highly resonant microwave structures. Three methods are proposed and compared to calculate pole‐free solutions to the Thiele continued fraction and vector fitting pole‐residue models of the characteristic equation det[Z(s)]. © 2007 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2007.     

VHF-PECVD制备微晶硅材料的均匀性及其结构特性的分析

采用VHF-PECVD技术在多功能系统(cluster tool)中制备了系列硅薄膜，研究薄膜的均匀性及电学特性和结构特性。结果表明：气压和功率的合理匹配对薄膜的均匀性有很大的影响；材料的喇曼测试和电学测试结果表明微晶硅薄膜存在着纵向的结构不均匀，在将材料应用于器件上时，必须要考虑优化合适的工艺条件；硅烷浓度大，相应制备薄膜的晶化程度减弱，即薄膜中非晶成分增多。     

Continued fraction for formal laurent series and the lattice structure of sequences

Besides equidistribution properties and statistical independence the lattice profile, a generalized version of Marsaglia's lattice test, provides another quality measure for pseudorandom sequences over a (finite) field. It turned out that the lattice profile is closely related with the linear complexity profile. In this article we give a survey of several features of the linear complexity profile and the lattice profile, and we utilize relationships to completely describe the lattice profile of a sequence over a finite field in terms of the continued fraction expansion of its generating function. Finally we describe and construct sequences with a certain lattice profile, and introduce a further complexity measure.     

Progress in near-field photothermal infra-red microspectroscopy

Near‐field photothermal Fourier transform infra‐red microspectroscopy, which utilizes atomic force microscopy (AFM)‐type temperature sensors, is being developed with the aim of achieving a spatial resolution higher than the diffraction limit. Here we report on a new implementation of the technique. Sensitivity of the technique is assessed by recording infra‐red spectra from small quantities of analytes and thin films. A photothermomechanical approach, which utilizes conventional AFM probes as temperature sensors, is also discussed based on preliminary results. Early indication suggests that the photothermal approach is more sensitive than the thermomechanical one.     

Optimal control of nonlinear systems to given orbits

Using optimal control techniques we derive and demonstrate the use of an explicit single-step control method for directing a nonlinear system to a target orbit and keeping it there. We require that control values remain near the uncontrolled settings. The full nonlinearity of the problem in state space variables is retained. The “one-step” of the control is typically a composition of known or learned maps over (a) the time required to learn the state, (b) the time to compute the control and (c) the time to apply the control. No special targeting is required, yet the time to control is quite rapid. Working with the dynamics of a well-studied nonlinear electrical circuit, we show how this method works efficiently and accurately in two situations: when the known circuit equations are used, and when control is performed only on a Poincaré section of the reconstructed phase space. In each case, because the control rule is known analytically, the control strategy is computationally efficient while retaining high accuracy. The target locations on the selected target trajectory at each control stage are determined dynamically by the initial conditions and the system dynamics, and the target trajectory is an approximation to an unstable periodic orbit of the uncontrolled system. A linear stability analysis shows that dissipation in the dynamical system is essential for reaching a controllable state.     

泡沫铝的声频内耗

研究了泡沫Ａｌ的声频内耗，结果表明：泡沫Ａｌ的内耗值比普通Ａｌ大一个量级以上，且随测量频率的增加而减小。出现了正常振幅效应。用平面波动方程，推导了泡沫Ａｌ的内耗与频率，孔隙率和孔径的关系，较好地解释了实验结果。     

克拉玛依原油中各组分的乳化性质

用沉淀法和色谱分离法将克拉玛依原油分离成沥青质，极性物和抽余油三组分，红外光谱分析表明，沥青质和极性物中存在一些含氧官能团的羧酸类或酚类以及含氮化合物，而抽余油则主要为烃类物质，因而沥青质和极性物的界面活性大于抽余油，沥青质具有较强的油包水（W／O）乳化能力，是造成克拉玛依原油W／O乳化的主要组分，极性物具有较强的水包油（O／W）乳化能力，是造成克拉玛依原油O／W乳化的主要组分，抽余油的乳化能力很弱。