61单元分立式压电变形反射镜的研制

用于校正波前误差的61单元分立式压电变形反射镜是61单元自适应光学系统（AO）的关键器件之一。由于系统对单元数（61单元）和变形量（±3μm）的要求超过以往曾研制的变形镜，对研制工作带来许多困难。我们从理论分析到工艺研究采取措施，使研制的变形镜成功用于AO系统实验。     

草酸二异辛酯的合成

以酸化膨润土(SO42-/Bentonite)固体酸为催化剂、草酸和异辛醇为原料合成草酸二异辛酯。考察了焙烧温度对催化剂活性的影响。结果表明,焙烧温度为500℃时催化剂活性最好。考察了反应温度、原料配比、催化剂用量和反应时间等因素对酯化反应的影响,确定了最佳酯化反应工艺条件,即n(异辛醇)∶n(草酸)为3.5∶1、w(SO42-/Bentonite)为2.0%、反应温度140℃、反应时间3 h;在该条件下草酸的转化率达到96.4%。催化剂重复使用6次后,草酸的转化率仍可达到94.4%。     

浅谈水库水温计算方法

在收集国内外水库水温分布预测方法的基础上,简要分析了影响水库水温分布的影响因素,介绍了当前常用的水库分层判别方法及水库水温预测的经验法,重点介绍了当前流行的数学模型法,同时对各方法的优、缺点及适用性进行了比较评价。     

Finite-difference analysis of dielectric-loaded cavities using thesimultaneous iteration of the power method with the Chebyshevacceleration technique

A numerical procedure using the finite-difference technique, simultaneous iteration based on the power method, and the Chebyshev-polynomial preconditioning is proposed to analyze dielectric-loaded cavities. The merit of this method is that no matrix inversions are invoked and the convergence rate of the power method is greatly accelerated by the preconditioning. The TE, TM, and hybrid modes in axisymmetrical cavities loaded with a rod or ring dielectric resonator are analyzed. For the hybrid modes, an H_r-H_z formulation is proposed. Accurate numerical results are obtained efficiently and no spurious solutions are found by the present method     

均匀设计在遗传算法中的应用研究

通过分析均匀设计和遗传算法的内在关系，指出从某个角度上可以把均匀设计看作是遗传算法的一种特例，并针对遗传算法初始参数众多、难配置的问题，提出了利用均匀设计优化配置选择参数的方法，在一定程度上可以避免遗传算法参数配置的盲目性．仿真试验结果证明了该方法是合理、可行的。     

Fuzzy estimation of feed-cutting force from current measurement-a case study on intelligent tool wear condition monitoring

It is very important to use a reliable and inexpensive sensor to obtain useful information about manufacturing processing, such as cutting force for monitoring automated machining. In this paper, the feed-cutting force is estimated using inexpensive current sensors installed on the ac servomotor of a computerized numerical control (CNC) turning center, with the results applied to the intelligent tool wear monitoring system. The mathematical model is used to disclose the implicit dependency of feed-cutting force on feed-motor current and feed speed. Afterwards, a neuro-fuzzy network is used to identify the cutting force with current measurement only. This hybrid math-fuzzy approach will reduce the modeling uncertainty and measurement cost. Finally, the estimated cutting force is applied in the tool-wear monitoring process. Successful experiments demonstrate robustness and effectiveness of the suggested method in the wide range of tool-wear monitoring applications.     

淤泥地基上土石围堰设计方案的探讨

新会区东南、中南部属冲积平原,西江、潭江两水横贯其中,岛丘众多,主干道时分时合,纵横交错,形成广阔的沙田地带,因此,堤围上也修建了相当数量的水闸,以满足防洪、排涝、航运以及灌溉的要求。水闸多为破堤而建,需要填筑围堰来保证主体工程的顺利施工。沙田地区的地基往往比较松软,淤泥层较厚,下面以金牛头水闸重建加固工程为例,探讨淤泥地基上土石围堰设计。     

~(141)CeO_2经气管内注入后在肺及淋巴结内的动态分布

本文报告了应用γ放射性测量和放射自显影方法,观察~(141)CeO_2经气管内注入后在大鼠肺及局部淋巴结中动态分布的特点。实验结果表明,~(141)Ce 在肺内与在不同部位、不同个体和单个淋巴结中的分布都是很不均匀的;其滞留量随时间而变化。     

试论农村水电工程开发建设审批流程

水电事业的发展,对促进农村与县域经济发展和社会进步起到了积极作用。但同时出现了一些“四无”水电站(无立项、无设计、无验收、无管理),不仅造成水能资源的严重浪费,其无偿占用农田水利设施,与农业灌溉争水,也损害了农民利益,引起群众纠纷、上访事件,还造成事故隐患,严重危及公共安全。鉴于以上原因,笔者就水电开发建设程序作一探讨。