摘要：Based on the obtained data of half-lives（t1/2） for 31 polychlorinated biphenyl congeners（PCBs）, 3D quantitative structure-activity relationship（QSAR） pharmacophore was used to establish a 3D QSAR model to predict the t1/2 values of the remaining 178 PCBs, using the structural parameters as independent variables and lgt1/2 values as the dependent variable. Among this process, the whole data set（31 compounds） was divided into a training set（24 compounds） for model generation and a test set（7 compounds） for model validation. Then, the full factor experimental design was used to research the potential second-order interactional effect between different substituent positions, obtaining the final regulation scheme for PCB. At last, a 3D QSAR pharmacophore model was established to validate the reasonable regulation targeting typical PCB with respect to half-lives and thermostability. As a result, the cross-validation correlation coefficient（q2） obtained by the 3D QSAR model was 0.845（〉0.5） and the coefficient of determination（r2） obtained was 0.936（〉0.9）, indicating that the models were robust and predictive. CoMSIA analyses upon steric, electrostatic and hydrophobic fields were 0.7%, 85.9%, and 13.4%, respectively. The electrostatic field was determined to be a primary factor governing the tt/2. From CoMSIA contour maps, tl/2 increased when substi- tuents possessed electropositive groups at the 2＇-, 3-, Y-, 5- and 5＇- positions and electronegative groups at the 3-, 3＇-, 5-, 6- and 6＇- positions, which could increase the PCB stability in transformer insulation oil. Modification of two typical PCB congeners（PCB-77 and PCB-81） showed that the lgtl/2 for three selected modified compounds increased by 13%（average ratio） compared with that of each congener and the thermostability of them were higher, validating the reasonability of the regulatory scheme obtained from the 3D QSAR model. These results are expected to be beneficial in predicting tl/2 values of PCB homologues and d

摘要：通过向土壤样品溶液中添加海藻酸钙并辅以超声,提高多种雌激素(E1,E2,E3,EE2和BPA)的生物降解效率,采用中心复合设计及响应曲面优化方法确定最优降解条件,并通过生物降解性能关系(QSBR)分析雌激素理化性质对生物降解的影响.结果表明:在海藻酸钙增强生物降解体系中,5种雌激素同时降解的最优条件为超声3min,海藻酸钙的质量分数为5%,菌液添加量6mL;优化降解3d后,E1的降解率约为100%;7d后E3,BPA,EE2和E2的降解率分别约为52.65%,96%,96.90%和100%;雌激素的极性表面积(PSA)、辛醇-水分配系数(lg Kow)和表面张力为影响雌激素生物降解的主要参数;极性表面积和辛醇-水分配系数的交互作用、辛醇-水分配系数和表面张力的交互作用对雌激素的降解均表现为协同作用.

摘要：为了优化重卡驱动桥结构性能,实现整桥轻量化市场供应目标,以CAE/CAM技术为支撑平台展开相应研究。运用体系化布局思维,科学搭建数学模型,经CAE仿真分析与CAM协同生产,形成完整的轻量化设计车桥,并进行了样机试验。结果表明,轻量化设计后的整桥在满足噪声限值、B10寿命等关键性能参数的前提下,其质量相对减轻12.7%,传动效率达95%以上。该设计方法可为重卡其他零部件改进提供参考思路,尤其在轻量化研究领域,具有较强的应用推广前景。

摘要：本项目旨在对某重型卡车后驱动桥主减速器壳体进行轻量化改进设计,在缺乏原始数据的情况下,首先需要进行数据采集与数据处理。本文在简述了数据采集的原理及对比各种采集方式特点的基础上,基于逆向工程流程,运用逆向扫描设备,得到了该壳体的点云数据,继而利用Geomagic Wrap软件,进行了数据处理。运用该方式进行数据采集和处理,可显著提高工作效率,缩短产品开发周期,也为其他类似壳体零件的数据采集与数据处理提供了借鉴。