箱体类零件特征造型系统的设计

基于产品特征建模理论，以AutoCAD 2000为开发平台，应用其开发工具ObjectARX 3.0,发现了箱体类零件的特征造型，并能生存特征数据文件，以便实现与CAPP系统的连接。     

势箱中电子运动图像的绘制

研究了势箱中电子运动波函数及电子云图像的绘制方法，给出了用ABSIC语言编写的作图程序及绘制的二维和三维势箱波函数、电子云分布图。     

横隔板间距对悬挑箱梁畸变的影响

研究横隔板间距对悬挑箱梁畸变的影响。通过设置不同数量横隔板的悬挑箱梁在均布扭矩作用下，比较畸变效应和刚性扭转效应，得到最大畸变效应随横隔板密度的变化曲线。当横隔板间距d与截面最大尺寸b的比值大于0．5357时，闭口截面杆件的约束扭转分析应考虑畸变的影响，尤其对于高层核心筒结构。     

GCC box in<Emphasis Type="Italic">Arabidopsis PDF1.2</Emphasis> promoter is an essential and sufficient cis-acting element in response to MeJA treatment

The expression of Arabidopsis PDF1.2 gene isregulated by jasmonic acid (JA) and ethylene (ET). It also has been well documented that GCC box is an element responsive to ET, however, the responsive mechanism of JA in such plant defense gene expression is unclear. In this paper, the authors define the essential cis-acting element in PDF1.2 promoter responsive to methyl jasmonate (MeJA) through fragment deletions and site-directed mutageneses combiningAgrobacterium-mediated transient reporter gene expression in tobacco leaves. Firstly, the MeJA inducible expression o fPDF1.2 was confirmed by using the upstream -1.86 kb fragment of PDFI.2 gene. Secondly, the upstream -300— -243 bp fragment of the promoter was evidenced to respond to MeJA. To further characterize this promoter region, three point mutations were introduced into the -300— -243 bp fragment of the promoter. This result showed that the mutation of GCC box abolished MeJA induction, whereas the mutations of the G box-like and the imperfect palindrome sequence did not significantly decrease MeJA inducible effect, indicating that GCC box in PDFI.2 is essential for MeJA induction. The sufficient responsiveness to MeJA of this GCC box was further investigated by 4xGCC fused upstream to the CaMV 35S minimal promoter. This result suggested that the fused promoter was able to activate reporter gene expression in response to MeJA. Thus these results indicate that the GCC box in PDFI.2 is an essential and sufficient element to confer MeJA induction.     

浅谈箱梁预制施工中的质量控制

根据笔者在河南叶信、岭南高速公路预制箱梁的实践,阐述了一些控制预制箱梁质量的办法,并对施工中的一些经验教训加以概括。     

浅谈30m预制预应力砼箱梁的施工控制

结合商周高速公路SZTJ6合同段施工实践,介绍了30m预应力连续箱梁预制过程中施工的控制要点,质量控制方法和技术。     

浅议既有线天桥钢箱梁施工

文章就新塘站站后工程既有线天桥钢箱梁施工的运输和吊装方案提出解决方案，着重讨论了既有线天桥钢箱梁的运输方法。     

混凝土箱梁水化热温度场有限元分析

应用大型有限元分析软件ANSYS,模拟箱形梁水泥水化生热和对流边界条件,进行混凝土水化热温度场仿真计算,并与实测数据进行对比分析.结果表明,所建立的有限元分析模型可以精确地仿真实际混凝土温度场,可为类似工程借鉴.     

32 m预应力铁路混凝土箱梁厂房式预制技术

介绍了32m预应力混凝土箱梁预制的施工工艺,探讨了该施工工艺的技术难点及处理方法。