异丁醛氧化制丙酮热导气相色谱分析

本工作用２米４０１有机担体填充柱，在带四臂热导检测器的国产１０３型气相色谱仪上，仅８分钟将原料异丁醛、产物丙酮及水进行良好分离，并采用内标法定量，其最大平均偏差在±２％以内。方法简单、快速、准确     

凸轮的表面裂纹分析

本文对一凸轮的表面裂纹进行了分析。渗碳后表层残余奥氏体含量过高级网状碳化物导致该凸轮在精磨过程中出现了磨削裂纹，本文还提出了二次回火或冰冷处理等改进措施来防止磨削裂纹的产生。     

时变多变量系统辨识的一种方法

本文提出时变多变量系统辨识的一种新方法，并分析了算法的收敛性和稳定性。仿真例子表明所提出算法是有效的。     

双能X射线骨密度仪测定技术研究

以Ｌｕｎａｒ公司ＤＰＸ－Ｌ型双能Ｘ射线骨密度仪为例，研究引起测量误差的主要因素并提出质控措施。用自检模块、腰椎体膜评定仪器的体外测量精度好于１％。对１０位志愿者重复２次测量，体内精度对腰椎，ＭＰＤ（平均百分差）为０．４６，ＣＶ（变异系数）为０．７５；对股骨颈，ＭＰＤ为１．２６、ＣＶ为０．４７；Ｗａｒｄ’ｓ三角区ＭＰＤ为２．０１、ＣＶ为１．１４；大转子ＭＰＤ为１．６６、ＣＶ为０．７２。扫描图像由２位     

LiMn2O4纳米粉的湿化学合成与表征

采用湿化学方法，通过水溶液中的化学反应直接合成纳米级LiMn2O4化合物，其结构基本上为无定型，但XRD图谱中已出现LiMn2O4特征峰，说明在水溶液中已初步形成尖晶石结构，运用XRD，SEM，TG－DTA等现代检测手段对样品的性能进行进行了表征，XRD及SEM等分析结果表明，合成样品经简单热处理后，晶型结构完善，形貌规整，均匀，比表面积积显著减小，粒度明显变粗。TG－DTA热分析证明，样品在低于900℃的温度下进行热处理时，仅发生LiMn2O4的晶化过程，产物的化学组成稳定，该法合成锂离子电池正极材料LiMn2O4，具有工艺流程简单，产物的成分，结构及粒度均匀等特点。     

High concentration erbium doping of silicon-rich SiO2 thin films on silicon

In this work, high concentration erbium doping in silicon-rich SiO₂ thin films is demonstrated. Si plus Er dual-implanted thermal SiO₂ thin films on Si substrates have been fabricated by using a new method, the metal vapor vacuum arc ion source implantation with relatively low ion energy, strong flux and very high dose. X-Ray photoelectron spectroscopy measurement shows that very high Er concentrations on the surfaces of the samples, corresponding to 10 at.% or the doping level of 10²¹ atoms cm⁻³, are achieved. This value is much higher than that obtained by using other fabrication methods such as the high-energy ion implantation and molecular beam epitaxy. Reflective high-energy electron diffraction, atomic force microscopy and cross-section high-resolution transmission electron microscopy observations show that the excess Si atoms in SiO₂ matrix accumulate to form Si clusters and then crystallize gradually into Si nanoparticles embedded in SiO₂ films during dual-ion implantation followed by rapid thermal annealing. Er segregation and precipitates are not formed. Photoluminescence at the wavelength of 1.54 μm exhibits very weak temperature dependence due to the introduction of Si nanocrystals into the SiO₂ matrix. The 1.54-μm light emission signals from annealed samples decrease by less than a factor of 2 when the measuring temperature increases from 77 K to room temperature.     

城市污水处理行业发展建设问题探讨

介绍了我国城市水污染的现状及其危害程度。提出了城市污水处理行业发展、建设所面临的种种问题。诸如资金问题、标准问题、管网与污水处理厂的关系等。论述了城市排水管网建设与发展应遵循的原则。苦能明确，并遵循分期建设以近为主、远近期相结合的原则，就能使污染得到控制，使生存环境更加美好。     

Analogue implementation of a neural network controller for UPSinverter applications

An analogue neural-network controller for UPS inverter applications is presented. The proposed neural-network controller is trained off-line using patterns obtained from a simulated controller, which had an idealized load-current-reference. Simulation results show that the proposed neural-network controller can achieve low total harmonic distortion under nonlinear loading condition and good dynamic responses under transient loading condition. To verify the performance of the proposed NN controller, a hardware inverter with an analogue neural network (NN) controller (using mainly operational amplifiers and resistors) is built. Additionally, for comparison purposes, a PI controller with optimized parameters is built. Experimental results confirm the simulation results and show the superior performance of the NN controller especially under rectifier-type loading condition. Implementing the analogue neural-network controller using programmable integrated circuits is also discussed     

开滦集团公司煤层间配采模型的建立

运用线性规划建立了数学模型，解决了开栾集团公司煤层间的配采问题，提高了煤炭企业的经济效益，有利于企业实现可持续发展。     

瓶组气化站的建筑、结构设计要点

瓶组气化站的建筑，结构设计关系到安全，满足使用要求和投资的大小，本文根据多年的实践和最新的有关设计规范的要求，阐述瓶组气化站建筑，结构设计的要点。