户式中央空调发展方向的探讨

本文描述了我国户式中央空调的发展现状，分析了三种户式中央空调各自的特点，提出了把风管式机组作为我国户式中央空调的发展方向。     

丹江口工程大坝加高后的几个水力学问题

依托1∶100水工模型试验成果,重点介绍了丹江口大坝加高后的几个水力学问题如泄流能力、坝面压力特性、河床局部冲刷、下游河道流速流态、泄洪对电厂及航运的影响等.研究显示:大坝加高后泄流能力可满足设计要求,坝下河床冲刷加重,挑距加远,设计洪水22 300 m3/s时坝下冲坑最低点高程为43.0 m,各级泄量冲坑上游坡均缓于临界坡,也略缓于初期工程同级流量冲坑的上游坡;坝下600 m以内为护岸工程重点防护段,岸边流速为5.8～9.8 m/s;泄洪对丹江口电厂影响较小,对自备电站不利影响较为显著;最大通航流量6 200 m3/s时下游引航道口门区流态复杂,水流较混乱.     

Construction of a control system for disturbance rejection using a dual observer

A well‐known control system which can reduce the adverse effects of disturbances is a disturbance observer. However, in many cases of mechanical systems, system disturbances which do not satisfy the matching condition may be imposed. Therefore, it may be difficult to reduce the adverse effects of the disturbances by the traditional disturbance observer. In this paper, a method of control system synthesis for disturbance rejection using a dual observer is proposed. This method is based on the zeroing induced by the disturbance localization problem. This problem may be solved by dividing the state space into observable subspace and unobservable subspace. As compared with an H_∞ controller based on perfect observation, the usefulness of the proposed control system for disturbance rejection is demonstrated by numerical simulations for a two‐mass spring system. © 2002 Scripta Technica, Electr Eng Jpn, 138(4): 50–60, 2002; DOI 10.1002/eej.1138     

变异函数在进间砂体预测中的应用

应用变异函数探讨了砂体的定量预测问题。通过对北二东密井网试验区不同类型砂体，不同井网密和岩厚度的预测，检验了此方法的精度（为70％左右），在原方法的基础上，通过对预报精度的分析并结合精度地质研究进一步完善了该方法，提出二次建模法并应用于北二东西块聚驱井的砂岩厚度预测中，预测精度可提高5％以上，从而说明应用变异函数研究砂体的定量预测问题具有可借鉴性，可以为今后新井调整厚度的预测及砂体描述提供依据。     

求解复杂形状旋转体拉延毛坯直径的新方法--计算机作图查询法

提出了基于AutoCAD软件的确定复杂形状旋转体拉延毛坯直径的方法－计算机作图查询法，这种方法操作严谨，结果准确，比原有的3种方法简捷、快速，是一种值得推广的好方法。     

软体排在长江江新洲堤岸加固工程中的应用

介绍了长江江新洲堤段应用软体排护岸新型技术的情况，结合长江江新洲护岸工程对软体排施工、工艺、设备作简要叙述。     

注聚井注入状况诊断方法研究

在室内试验和动态分析的基础上，对引起注聚井注入困难的原因进行了分析，提出了利用单井动态预测结果和实际注入动态曲线对比判断聚合物注入状况的方法，建立了预测注聚井注入动态的预测模型，并对数值模拟计算结果进行了分析。同时还评价了现场应用效果。通过数值模拟和实际注入动态曲线对比，可以初步判断待措施井有无近井地带堵塞，为提高注聚井压解堵措施的有效性奠定了基础。     

Transient Green’s Tensor for a Layered Solid Half-Space With Different Interface Conditions

Pulsed ultrasonic techniques can be and have been used to examine the interface conditions of a bonded structure. To provide a theoretical basis for such testing techniques we model the structure as a layer on top of a half-space, both of different elastic properties, with various interface bonding conditions. The exact dynamic Green’s tensor for such a structure is explicitly derived from the three-dimensional equations of motion. The final solution is a series. Each term of the series corresponds to a successive arrival of a “generalized ray” and each is a definite line integral along a fixed path which can be easily computed numerically. Willis’ method is used in the derivation. A new scheme of automatic generation of the arrivals and ray paths using combinatorial analysis, along with the summation of the corresponding products of reflection coefficients is presented. A FORTRAN code is developed for computation of the Green’s tensor when both the source and the detector are located on the top surface. The Green’s tensor is then used to simulate displacements due to pulsed ultrasonic point sources of known time waveform. Results show that the interface bonding conditions have a great influence on the transient displacements. For example, when the interface bonding conditions vary, some of the first few head waves and regular reflected rays change polarities and amplitudes. This phenomenon can be used to infer the quality of the interface bond of materials in ultrasonic nondestructive evaluation. In addition the results are useful in the study of acoustic microscopy probes, coatings, and geo-exploration.     

A non—perturbation approach in temperature Green function theory

A set of differo-integral equations for many-body connected temperature Green‘s functions is established which is non-perturbative in nature and provides a reasonable truncation scheme with respect to the order of many-body correlations.The method can be applied to nuclear systems at finite temperature.     

模拟电路的模块级故障诊断

本文以多端口元件或子网络为基本单元，提出了一种模块级故障诊断方案，这种方案的故障模型更符合电路的实际情况，因而具有更广泛的实际意义，文中首先推导了模块故障诊断议程，并对模块故障可测性问题进行了一般性讨论。然后，给出了模块故障可测的几个拓扑条件，并通过定义广义独立通路使这些拓扑条件适用于一般的非互易网络。