Deformation heterogeneity of Ti under cryogenic channel-die compression

Commercial purity Ti was subjected to channel die compression in liquid nitrogen for the purpose of studying its deformation characteristics from the viewpoint of the grain refinement induced by seve re plastic deformati on. Deformed specimens showed microstructural heterogeneity in that the initial blocky grains of about 50 μm in size turned into a mixture of the easily deforming soft grains and the hard grains revealing local concentration of dislocati ons and deformation twins. Using electron back scattered diffraction analysis the in-grain misorientation-axis distribution was studied, from which it was found that the deformation heterogeneity resulted from the anisotropy of individual grains with respect to the compression die: while the soft grains were those oriented favorably for the prism < a> slip, the hard ones were oriented for non-prism slips and deformation twinning. The difference in the response of individual grains, therefore, led to a remarkable effect of the crystal texture of specimens on the maximum strain that can be imposed on specimens without cracking. Based on the present results, a way to achieve expedient grain refinement through the cryogenic plane-strain compression was suggested.     

难处理金精矿的加压氧化一氯化浸出实验

采用加压氧化法对国内某难处理金精矿进行预处理,考察了反应温度、精矿粒度、氧分压、初酸浓度、反应时间对金精矿脱硫率和金浸出率的影响.利用XRD,XRF,SEM,EDX技术对金精矿原矿及浸出渣进行分析表征,实验结果表明,在反应温度180℃,精矿粒度-0.075～+0.061 mm,氧分压0.8 MPa,初酸质量浓度60 g...     

Distributed location-based query processing on large volumes of moving items

Recently,new techniques to efficiently manage current and past location information of moving objects have received significant interests in the area of moving object databases and location-based service systems. In this paper,we exploit query processing schemes for location management systems,which consist of multiple data processing nodes to handle massive volume of moving objects such as cellular phone users. To show the usefulness of the proposed schemes,some experimental results showing performance factors regarding distributed query processing are explained. In our experiments, we use two kiids of data set：one is generated by the extended GSTD simulator and another is generated by the real-time data generator which generates location sensing reports of various types of users having different movement patterns.     

TiO2对共沉淀法制备Pd/Al2O3-TiO2催化活性的影响

文中采用共沉淀法制备了混合载体质量分数为1%的Pd/Al₂O₃-TiO₂催化剂，借助XRD和XPS对样品进行了表征，结果表明：混合载体Al₂O₃-TiO₂为无定形结构；TiO₂降低了Pd和Al₂O₃的相互作用能力。将样品应用于C₃H₆选择催化还原NO反应，以NO转化率为活性评价指标对催化剂的活性进行了对比，发现TiO₂的含量对催化剂活性有显著影响：随着TiO₂质量分数从0增加至50%，催化剂活性迅速增加；TiO₂质量分数超过50%，催化剂活性增加趋势变缓。     

Version based spatial record management techniques for spatial database management system

The search operation of spatial data was a principal operation in existent spatial database management system，but the update operation of spatial data such as tracking are occurring frequently in the spatial database management system recently. So，necessity of concurrency improvement among transactions is increasing. In general database management system，many techniques have been studied to solve concurrency problem of transaction. Among them，multi-version algorithm does to minimize interference among transactions. However，to apply existent multi-version algorithm to improve concurrency of transaction to spatial database management system， the waste of storage happens because it must store entire version for spatial record even if only aspatial data of spatial record is changed. This paper has proposed the record management techniques to manage separating aspatial data version and spatial data version to decrease waste of storage for record version and improve concurrency among transactions.     

全球当地化:中国家电企业攻克韩国市场的必由之路

中国正在从家电制造大国向家电技术强国方向迈进,其家电产品已销往世界各地,但韩国市场却仍是中国家电企业的"软肋"。究其因一是难敌韩国家电品牌,二是韩国消费者高度忠诚于本国品牌。因此,中国家电在韩国市场上必须采取相应的目标市场和定位战略,在迎合韩国家电市场消费需求和偏好的基础上,强化当地化营销策略和行动。     

机构系统概念设计中功能到行为的映射方法

基于功能-行为-结构映射的机构系统概念设计模型,通过与功能相关联物理行为的综合,实现功能到结构的转换;通过分析执行动作形式,定义了有效工作时段的动作形式;在确定工作原理的条件下,建立了构造功能与有效工作时段动作映射矩阵的方法.根据专家经验,对能实现一个功能的所有有效工作时段动作进行评价,建立了从整个工艺动作过程的动作方案,集中寻求最优化有效工作时段动作方案的评价规则、数学模型和求解方法,并给出实例.     

A model for knowledge transfer in a multi-agent organization based on lattice kinetic model

A study on knowledge transfer in a mutli-agent organization is performed by applying the basic principle in physics such as the kinetic theory.Based on the theoretical analysis of the knowledge accumulation process and knowledge transfer attributes,a special type of knowledge field(KF)is introduced and the knowledge diffusion equation(KDE)is developed.The evolution of knowledge potential is modeled by lattice kinetic equation and verified by numerical experiments.The new equation-based modeling developed in this paper is meaningful to simulate and predict the knowledge transfer process in firms.The development of the lattice kinetic model(LKM)for knowledge transfer can contribute to the knowledge management theory,and the managers can also simulate the knowledge accumulation process by using the LKM.     

采用邻居节点的改进ZigBee路由选择算法

在无线传感网络中,路由选择是高效使用网络、延长全网络寿命的关键之一.为了提高网络效率和节省网络整体能耗,提出了一种路由选择优化算法,该算法利用没连接到的邻居节点进行数据路由选择,以减少从源节点到目的节点的跳数,进而达到提高网络效率和节省能耗的目的.通过仿真实验对比分析了改进前后的实际效果,实验结果表明改进后的路由选择优化算法减少了ZigBee节点间路由的跳数和延迟,提高了路由效率,节省网络整体能耗.