镍催化合成二元酮化物的研究

有机锡试剂与酰氯化合物的交叉偶联反应提供了合成有机酮化物的新方法。以往有机酮化物的合成常采用锂试剂和格林试剂,它们能与生成的产物酮进一步反应,对空气也很敏感。反应条件比较苛刻,常要求在低温和无氧条件下进行,同时为防止锂试剂和格林试剂在反应时发生消除副反应,对它们的纯度要求也很高。而采用有机锡试剂,则克服和解决了由格林试剂和锂试剂合成有机酮时所无法解决的问题。其主要特点是化学     

分子筛晶内扩散系数测定的新公式

用程序升温热脱附方法，通过一次实验即可得到不同温度的分子筛晶内扩散系数，考虑到在脱附初期，吸附分子的浓度较大，可能存在相互作用的影响，本文提出了处理热脱附失重曲线的新公式，并用两组分子筛样品进行了验证，结果表明，新公式明显优于旧公式。     

关于高等学校实验队伍建设规范的探讨

中就高等学校实验队伍的编制，结构规范作了探讨，以求实验队伍建设的科学化，规范化，为各类高等学校实验队伍的建设提供参考。     

深层搅拌桩加固软土地基值得注意的几个问题

通过对深层搅拌桩软土地基加固机理的介绍,从膨胀挤密、脱水固结、胶结凝固等深层搅拌桩软土地基加固机理方面和深层搅拌桩适用的范围、水泥标号与掺入比、设计桩长与桩的置换率、搅拌桩的承载力与沉降等设计方面及深层搅拌桩施工机械类型比较、操作程序、外掺剂种类等施工工艺方面，提出既经济又能保证深层搅拌桩施工质量需注意的几个问题，可为类似工程的设计、施工提供一定的借鉴.     

Samples Selection for Artificial Neural Network Training in Preliminary Structural Design

An artificial neural network (ANN) is applied in the preliminary structural design of reticulated shells. Major efforts are made to enhance the generalization ability of networks through well-selected training samples. Number-theoretic methods (NTMs) are adopted to generate samples with low discrepancy, i.e.uniformly scattered in the domain, where discrepancy is a quantitative measurement of the uniformity. The discrepancy of the NTM-based sample set is 1/6-1/7 that of samples with equal spacing. In a case study,networks trained by NTM-based samples are compared with those trained by equal-spaced samples in generalizing performance. The results show that both the computational precision and stability of the former ANNs are more satisfactory than those of the latter. It is concluded that the flexibility of ANNs in generalizing can be effectively increased by use of uniformly distributed training samples rather than simply piling data.More reliable uniformity should be obtained, however, through NTMs instead of equal-spaced samples.