Closed-form solutions for one-dimensional inhomogeneous anisotropicmedium in a special case. I. Direct scattering problem

An analytical formulation is presented for the direct scattering problem of one-dimensional (1-D) inhomogeneous anisotropic medium in a special case. This method gives nonlinear differential equations for the reflection coefficients of the anisotropic medium. Applying the discontinuity condition of the dielectric parameters at the interface of the medium with free space, approximate closed-form solutions for the reflection coefficients are obtained. Numerical examples show the validity of the method     

下运带式输送机液压制动系统的研究

首先对下运带式输送机的制动问题进行了分析,而后介绍了一种新型液压制动系统的基本原理、组成和用途,以及液压制动系统的控制要求和工作状态。实践结果表明,采用该液压制动系统从根本上保证了大倾角下运带式输送机的安全高效生产。     

浅除盐水技术在合成氨水处理工艺中的应用

在合成氨生产过程中，要根据不同的工序要求对用水进行净化处理，很多合成氨生产厂尤其中小合成氨厂的水处理主要采用仅除去硬度的软化水作为一般蒸气锅炉给水和工艺用水。有自备电站的成氨厂锅炉炉水一般采用一级复床除盐水系统制备除盐水（电导率≤１０μｓ／ｃｍ） 工艺软化水制造成本低但其仅除去原水中的硬度而盐分没有减少，作为锅炉给水造成锅炉排污量大热损失大作为工艺用水常引起合成系统变换催化剂的表面结垢等门题，除盐水的水质好，能完全满足合成氨生产工艺用水的需要，但其制造成本为工艺水的几倍。本文主要介绍浅除盐水技术…     

基坑工程表观监测与安全预警问题的研究

该文阐述了基坑工程的基本特点及复杂性 ,介绍了基坑工程表观监测的基本方法及监测中的若干技术问题 ,提出了基坑工程安全预警的一些量化指标。     

农村饮水工程适宜水质净化技术

农村饮水工程根据不同的原水水质条件，宜采用不同的水质净化技术。对地表水浑浊度长年低于20NTU、瞬间不超过60NTU原水，可采用微絮凝直接过滤加消毒或慢滤加消毒净化工艺；浑浊度长年低于500NTU、瞬间不超过1000NTU的原水，采用混凝沉淀（澄清）过滤、消毒的常规净水工艺。对于特殊水质如氟超标的地下水、砷超标的地下水、苦咸水及其他污染水，根据不同情况，可分别采用活性氧化铝吸附法、混凝沉淀法、多介质过滤法、铁盐混凝沉淀法、电渗析法、反渗透法等不同方式予以处理。     

Effect of RE on Granulation of Eutectic Carbide in Ledeburite Steel

ＲｅｃｅｎｔｌｙｔｈｅｂｅｎｅｆｉｃｉａｌａｃｔｉｏｎｓｏｆＲＥｏｎｉｒｏｎａｎｄｓｔｅｅｌｓｈａｖｅｂｅｅｎｒｅｐｏｒｔｅｄａｒｏｕｎｄｔｈｅｗｏｒｌｄ．ＲＥｃａｎｎｏｔｏｎｌｙｄｅｏｘｉｄｉｚｅａｎｄｄｅｓｕｌｐｈｕｒｉｚｅｔｈｅｍｅｌｔａｎｄｆ...     

Biological Effects of Flammulina Velutipes Richin RE on Chinese Kunming Mice

ＢｉｏｌｏｇｉｃａｌＥｆｆｅｃｔｓｏｆＦｌａｍｍｕｌｉｎａＶｅｌｕｔｉｐｅｓＲｉｃｈｉｎＲＥｏｎＣｈｉｎｅｓｅＫｕｎｍｉｎｇＭｉｃｅＬｉａｎｇＤｉｎｇｂａｎｇ（梁定邦）；ＣｕｉＤｅｆａｎｇ（崔德芳）；ＺｈａｎｇＪｉｎｔｏｎｇ（张金桐）（Ｄｅｐａｒｔｍ...     

钨带灯的稳定性判据试验

我们通过对国产ＢＷ—１４００型真空钨带灯的稳定性判据进行研究，发现通过钨带灯的电流达到稳定的时间很短（小于５分钟），而钨带灯的灯电阻需要经过２０分钟后才能达到稳定，因此，用电流稳定性作为钨带灯的热平衡判据是不够的，更可靠的判据还应看灯电阻是否达到平衡。     

Simple Question Answering over Knowledge Graph Enhanced by Question Pattern Classification

Knowledge and Information Systems - Question answering over knowledge graph (KGQA), which automatically answers natural language questions by querying the facts in knowledge graph (KG), has drawn...     

The parameterized level set method for structural topology optimization with shape sensitivity constraint factor

In recent years, the parameterized level set method (PLSM) has attracted widespread attention for its good stability, high efficiency and the smooth result of topology optimization compared with the conventional level set method. In the PLSM, the radial basis functions (RBFs) are often used to perform interpolation fitting for the conventional level set equation, thereby transforming the iteratively updating partial differential equation (PDE) into ordinary differential equations (ODEs). Hence, the RBFs play a key role in improving efficiency, accuracy and stability of the numerical computation in the PLSM for structural topology optimization, which can describe the structural topology and its change in the optimization process. In particular, the compactly supported radial basis function (CS-RBF) has been widely used in the PLSM for structural topology optimization because it enjoys considerable advantages. In this work, based on the CS-RBF, we propose a PLSM for structural topology optimization by adding the shape sensitivity constraint factor to control the step length in the iterations while updating the design variables with the method of moving asymptote (MMA). With the shape sensitivity constraint factor, the updating step length is changeable and controllable in the iterative process of MMA algorithm so as to increase the optimization speed. Therefore, the efficiency and stability of structural topology optimization can be improved by this method. The feasibility and effectiveness of this method are demonstrated by several typical numerical examples involving topology optimization of single-material and multi-material structures.