空间数据模型发展综述

介绍了各发展阶段的典型空间数据模型,从商业软件和模型的标准化两个方面阐述了空间数据模型的发展现状。在综合现有理论和成果的基础上,总结了当前空间数据模型发展的不足以及今后的发展趋势。     

基于χ~2检验的施工安全监管中行为因素关联分析

水利工程施工中的安全监管错误会引发不安全行为,进一步影响施工人员的工作状态,最终导致事故的发生.基于χ2独立性检验,通过统计学分析提供邻近层次的不同种类之间因素的概率数据,对行为因素之间的独立性进行关联分析,从中找到非独立的因素;确定了人为因素分析与分类系统(HFACS)框架中高层次对底层次因素的影响程度.最后在这些数据的基础上,找到HFACS框架中各因素的作用路径,为防范措施的制定和实施准备工作提供了依据和参考.     

烷烃临界参数的定量构效关系研究

定义了分子中原子的平衡电负性并用原子的平衡电负性对分子图进行着色，在距离矩阵的基础上结合分子中各原子的支化度构建一种新的拓扑指数ND1、ND2、ND3，它对分子结构实现唯一性表征具有优良的结构选择性，并与烷烃临界温度、临界压力和临界体积相关联，相关系数分别为0．9986,0．9980,0．9966，预测结果令人满意。     

做好班主任工作构建和谐班集体

构建和谐班集体是构建和谐校园的重要载体。当前，应该从构建和谐的教育环境、人际关系，促进班级管理、个性发展的和谐等四个方面来着手构建和谐班集体，为每个学生的全面发展营造一个友善、民主、平等、相互竞争、共同进取的良好氛围，为现代社会培养全面发展、具有综合素质的多样化人才。     

钢管混凝土压弯构件荷载—挠度曲线的全过程分析

本文主要采用筒支梁式加载方案，研究钢管混凝土压弯构件荷载－挠度关系曲线，试验的主要参数是轴压比、剪跨比和含钢率。最后通过理论计算和对试验数据进行回归分析得到极限承载力、极限位移的计算公式和荷载－挠度关系曲线。     

青霉烯类抗生素及其构效关系

青霉烯是一类抗菌谱广、抗菌活性高、对肾脱氢肽酶-Ⅰ稳定的抗生素。介绍了青霉烯类抗生素的特征、抗菌性及其活性的构效关系，及用分子力学和分子轨道方法对其构效关系进行的理论阐述。     

Investigation of Polyimidesiloxanes for Use as Adhesives by Electron Spectroscopy for Chemical Analysis

Angle-dependent electron spectroscopy for chemical analysis (ESCA) was used to examine the air facing surface (20–100 Å thick) composition of polyimidesiloxanes with different processing variations, and of varying polydimethylsiloxane (PDMS) content and block length (number of PDMS repeat unit varies from 1 to 9). Polyimide was clearly detected (due to the nitrogen content) in the 20–100 Å surface regions. This shows that a small amount of PDMS and short PDMS segment lengths in polyimidesiloxanes give a surface region with both PDMS and polyimide present. The surface composition, particularly that in the ca. 100 Å region, was correlated to the peel strength of polyimidesiloxane melt pressed to a metal substrate. Our results suggest that both PDMS and polyimide are essential components to rendering a needed peel strength. PDMS, having a good diffusive ability, readily reaches the substrate upon being pressed, achieving intimate contact, while imide groups interact with the substrate, presumably through chemical bonding; these two factors act synergistically to result in a high peel strength. In addition, the interaction mechanism and the failure mechanism involved in bonding polyimidesiloxane and metal substrate were also elucidated based on the ESCA results.     

Ordered mesoporous silica prepared by quiescent interfacial growth method - effects of reaction chemistry

Acidic interfacial growth can provide a number of industrially important mesoporous silica morphologies including fibers, spheres, and other rich shapes. Studying the reaction chemistry under quiescent (no mixing) conditions is important for understanding and for the production of the desired shapes. The focus of this work is to understand the effect of a number of previously untested conditions: acid type (HCl, HNO₃, and H₂SO₄), acid content, silica precursor type (TBOS and TEOS), and surfactant type (CTAB, Tween 20, and Tween 80) on the shape and structure of products formed under quiescent two-phase interfacial configuration. Results show that the quiescent growth is typically slow due to the absence of mixing. The whole process of product formation and pore structuring becomes limited by the slow interfacial diffusion of silica source. TBOS-CTAB-HCl was the typical combination to produce fibers with high order in the interfacial region. The use of other acids (HNO₃ and H₂SO₄), a less hydrophobic silica source (TEOS), and/or a neutral surfactant (Tweens) facilitate diffusion and homogenous supply of silica source into the bulk phase and give spheres and gyroids with low mesoporous order. The results suggest two distinct regions for silica growth (interfacial region and bulk region) in which the rate of solvent evaporation and local concentration affect the speed and dimension of growth. A combined mechanism for the interfacial bulk growth of mesoporous silica under quiescent conditions is proposed.