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%。     

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。     

调节阀的闪蒸和气蚀

针对调节阀的闪蒸和气蚀问题，介绍了调节阀在选型和使用中的要点。     

燃气管网模拟分析软件的开发与应用

介绍了以牛顿节点法模型为基础、应用VB语言开发管网分析软件的思路和方法,开发的软件具有实用性、稳定性和易操作性.结合实例,说明了软件在天然气转换方案选择、事故工况分析等领域的应用.     

加氢裂化工艺辅助操作与管理专家系统的开发与应用

近来，专家系统技术的利用已成火炼油与石油化工专家们感兴趣的问题。本文评述了国外这些领域中专家系统应用的进展概况。同时，对我们开发的专家系统工具ＦＥＸＳ的性能作了简介。详述了工业加氢裂化装置辅助操作与管理专家系统的研制过程和系统配置，讨论了系统开发的经验。最后，评价了该技术在炼油与石油化工业中的应用前景。