New inverse method for identification of constitutive parameters

A new inverse method by coupling iSIGHT and ABAQUS was proposed to determine the constitutive parameters of Al2O3sf/LY12 composite deforming at elevated temperature. It combined the merits of the f＇mite element simulation and optimization technique. The direct model was simulated with finite element code ABAQUS. The inverse problem associated with the identification of the constitutive parameters was expressed as a least square optimization problem. The direct simulation and the parameters optimization were implemented in iSIGHT integrated environment. The aim was to match the output of the direct simulation with the experiment data. The capability of the proposed inverse method was demonstrated through the identification of constitutive parameters of Al2O3sf/LY12 composite. The proposed new inverse method is also applicable to other parameters identification which is hardly determined through experiments or direct analytical method.     

Preparation of alumina-doped yttria-stabilized zirconia nanopowders by microwave-assisted peroxyl-complex coprecipitation

Alumina-doped yttria-stabilized zirconia （ADYSZ） nanopowders were prepared by microwave-assisted peroxyl-complex coprecipitation （MAPCC） using ZrOCl2-8H2O, Y2O3 and AICly6H2O as starting materials, NH2-H2O as precipitant and H2O2 as complexant. The effects of adding H2O2 and microwave drying on the preparation and properties of ADYSZ were investigated. The precursors and nanopowders were studied by EDX, XRD, SEM and TEM techniques. The results show that the uniformity of component distribution within ADYSZ nanopowders is improved by adding appropriate dosage of H2O2. Complexing reaction between H2O2 and Zr^4＋ ion restrains the hydrolyzation and precipitation of Zr^4＋ ion. With the addition of H2O2, Al^3＋, y^3＋ and Zr^4＋ ions can be precipitated synchronously in a relatively narrow range of pH value. H2O2 also improves the filterability of the wet precipitate. The highly hydrophilic precipitates can be quickly and effectively separated from aqueous solution. During microwave drying process, the moisture of wet precursors is selectively heated. Quick expansion of steam vapor within the wet colloidal particles causes the aggregations burst into numerous tiny lumps. Compared with oven drying, microwave drying can not only shorten drying time but also reduce aggregation intensity of the resultant ADYSZ nanopowders.     

基于Profibus_DP的柔性制造系统的设计

为提高自己对外界环境变化的响应速度,国内外先进企业纷纷建造柔性制造系统。系统的实时通信是实现柔性制造系统的关键技术,针对传统柔性制造系统中通信方式的缺陷,文中提出了以现场总线Profibus_DP作为柔性制造系统的通信方式,构建了三层柔性制造系统的控制结构,探讨了一类主站和二类主站之间以及主站和从站之间的通信实现方法,最后通过JK_FMS柔性制造系统的开发,验证了该方案的可行性。     

快干涂料铸渗法获得铸件表面复合层的研究

对快干涂料法铸渗工艺进行了研究。查明了影响铸件表面复合层质量的主要工艺因素,确定了最佳工艺参数,为生产实践提供了依据。     

正交试验优化电镀Zn-Ni-P合金工艺

选取影响电镀Zn-Ni-P合金的6个工艺参数，设计了125(56)正交试验方案，探讨了镀液组成和电镀制度对Zn-Ni—P合金镀层性能的影响，用极差法分析了各工艺参数对镀层性能影响的显著性并确定了最佳工艺条件。优化验证实验结果表明：该工艺稳定，得到光亮、致密、外观平整的Zn-Ni—P合金镀层，得到的锌镍磷合金镀层的耐蚀性优于锌镍合金，且其耐蚀性随镀层中磷含量的增大而提高。     

分子动力学模拟铜纳米团簇的结构稳定性

利用分子动力学研究了原子数为13～1 055的铜纳米团簇.结果表明:随着尺寸的减小,铜纳米团簇的结构发生晶体→非晶→晶体→非晶→晶体→非晶的转变.团簇平均原子结合能随着尺寸的减小而减小,且只依赖于短程有序,这说明了团簇平均原子结合能一般不能够作为非晶与密堆结构晶体转变的判据.平均原子间距不但依赖于团簇的尺寸,且对团簇结构的变化敏感,可以作为非晶与密堆结构晶体转变的一个判据.对偶分布函数的研究表明,大尺寸团簇的内部和表层原子结构都表现出晶格收缩效应,且不同于相应块体晶格,这表明了目前文献中关于团簇的块体加表面模型与壳核模型都有待改进.     

Co和Cu薄膜电学特性和连续性特征的判据

采用离子束溅射沉积了不同厚度的Co膜和Cu膜,利用四电极法测量了薄膜的电阻率,从而得到了Co膜和Cu膜的电导率随薄膜厚度的变化关系。实验结果表明,Co膜和Cu膜的电学特性都具有明显的尺寸效应。比较了同时考虑表面散射和晶界散射的电导理论得到的电导率公式与实验结果,不同薄膜厚度电导率的理论结果与实验结果符合较好。提出了厚度作为金属薄膜生长从不连续膜进入连续膜的一个特征判据,并利用原子力显微镜(AFM)观测了膜厚在特征厚度附近的Co膜和Cu膜的表面形貌。     

DXF文件中标题栏及明细表信息获取方法

电力系统企业中大量使用AutoCAD制作的工程图纸,企业实施信息管理系统或ERP系统的过程要求从这些图纸中直接获得其中的物料信息和图纸的一些基本信息。针对这种应用需求简要地分析了DXF文件的格式,然后根据明细表和标题栏的各自不同的特性生成读取信息的方法,该方法可快速地从大量图纸中批量地读取信息,这些信息可以直接为信息管理系统或ERP系统所使用。     

S-苄基-L-半胱氨酸的合成

由溴化苄和L-半胱氨酸直接合成S-苄基-L-半胱氨酸,通过正交试验及统计分析,检验了各影响因子的显著性,确定了最佳工艺条件为：反应时间2.5h,反应温度45℃,原料配比n（溴化苄）：n（L-半胱氨酸）=1：1.在此条件下反应,摩尔产率可达到95%.