The Densification of Cu／Ti System by Spark Plasma Sintering

In order to unclose the dynamics of SPS densification, a special sintering sample (Cul Ti wires compact) was designed. Characters of the shrinkage rates during sintering process and mierostructures of products fabrieated by the spark plasma sintering( SPS ) and hot-press .sintering were investigated. The experimental results reveal that a higher temperature field is formed at the connected area and conductive net of the compact. These high-temperature parts deformed more easily than other parts, which is believed to be the main cause of SPS fast densification, according to a hard-core and soft-hell material model.     

Probe into Key Techniques of Regional-Oriented 3D GIS On the key techniques of 3D GIS used for regional Geological Information System

Regional Geological Information System combines the multi-dimensional and dynamic spatial information into an integrated spatial information system. 3D geological modeling and its preprocessing or post-processing are the most difficult problems for constructing the system. Based on the current 3D GIS technique, some basic problems in establishing the system are discussed in this paper, including 3D spatial data model, 3D geological modeling, and visualization of 3D geological data. A kind of 3D vector data model based on boundary representation for geological object and its topology was developed in order to model and visualize complex geological structures. In addition, some key techniques are pointed out for further study.     

Reflected Appraisals, Academic Self-Perceptions, and Math/Science Performance During Early Adolescence.

The authors tested a model of the relations among adolescents' perceptions of parents', teachers', and classmates' support for, valuing of, and beliefs about their competence in math/science; adolescents' own academic self-perceptions concerning math/science; and their academic performance. The sample included 378 middle school students; 65% were Latino, and 21% were European American. Reflected appraisals of adults' beliefs concerning both the importance of and students' competence in math/science, as well as perceived support, predicted students' own self-perceived importance, competence, scholastic behavior, and performance in these courses. Latino students reported lower mean levels of perceived competence than did European American students (controlling for maternal education). Findings have important implications for understanding achievement socialization in ethnically diverse populations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Discrepancy in Analyses of the MSCEIT--Resolving the Mystery and Understanding Its Implications: A Reply to Gignac (2005).

Replies to comments made by G. E. Gignac (see record 2005-06671-010) on the current authors' original article (see record 2003-02341-015). Gignac reanalyzed the factor structure of the Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT) and found results that differed from those the authors obtained initially. The authors tracked down the surprising sources of those discrepancies. G. E. Gignac's hierarchical model of emotional intelligence appears promising, and the authors anticipate that further investigations of the MSCEIT factor structure may yield additional information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Theoretical Correlations and Measured Correlations: Relating Recognition and Recall in Four Distributed Memory Models.

This article addresses the relation between item recognition and associative (cued) recall. Going beyond measures of performance on each task, the analysis focuses on the degree to which the contingency between successful recognition and successful recall of a studied item reflects the commonality of memory processes underlying the recognition and recall tasks. Specifically, 4 classes of distributed memory models are assessed for their ability to account for the relatively invariant correlation (≈ .5) between successive recognition and recall. Basic versions of each model either under- or overpredict the intertask correlation. Introducing variability in goodness-of-encoding and response criteria, as well as output encoding, enabled all 4 models to reproduce the moderate intertask correlation and the increase in correlation observed in 2 mixed-list experiments. This model-based analysis provides a general theoretical framework for interpreting contingencies between successive memory tests. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

大断面结构参数计算机模拟研究

为了解决弓长岭井下在矿体倾角较大、下盘围岩不稳固的情况下矿石回收率低的问题,本文从弓长岭铁矿的实际应用出发,深入研究了放矿口对散体移动规律的影响,在分析模拟系统的设计要求及功能的基础上,对D.Jolley模型进行建模.采用C#开发了计算机模拟系统,模拟实现了大断面出矿的一系列过程。该系统能够对多种方案进行模拟,并对模拟结果进行选优。仿真结果表明大断面进路出矿对提高矿石回收率的正确性及有效性。     

Calibration of the Weibull stress scale parameter, σu, using the Master Curve

This work proposes that the Weibull stress scale parameter, σ_u, increases with temperature to reflect the increasing microscale toughness of ferritic steels caused by local events that include plastic shielding of microcracks, microcrack blunting, and microcrack arrest. The Weibull modulus, m, then characterizes the temperature invariant, random distribution of microcrack sizes in the material. Direct calibration of σ_u values at temperatures over the DBT region requires extensive sets of fracture toughness values. A more practical approach developed here utilizes the so-called Master Curve standardized in ASTM Test Method E1921-02 to provide the needed temperature vs. toughness dependence for a material using a minimum number of fracture tests conducted at one temperature. The calibration procedure then selects σ_u values that force the Weibull stress model to predict the Master Curve temperature dependence of K_Jc values for the material. At temperatures in mid-to-upper transition, the process becomes more complex as fracture test specimens undergo gradual constraint loss and the idealized conditions of high-constraint, small-scale yielding assumed in E1921-02 gradually degenerate. The paper develops the σ_u calibration process to incorporate these effects in addition to consideration of threshold toughness effects and the testing of fracture specimens with varying crack-front lengths. Initial illustrations of the calibration process for simpler conditions, i.e. 1T crack-front lengths, use the temperature dependent flow properties and a range of toughness levels for an A533B pressure vessel steel. Then using the extensive fracture toughness data sets for an A508 pressure vessel steel generated recently by Faleskog et al. [Engng. Fract. Mech., in press], the paper concludes with calibrations of both m and σ_u over the DBT region and assessments of the Master Curve calibration approach developed here.     

基于VB6．0的灰色建模系统开发及其应用

灰色系统理论是应用广泛的、用于不确定问题建模和不确定信息系统数据挖掘的一门新兴横断学科。基于VB6.0的灰色建模系统的开发填补了灰色系统理论及其应用的空白。文中阐述了该系统的开发思想、应用流程及几个关键技术,并以2002～2005年上海市上网户数预测为例,介绍了其子程序GM(1,1)的用法。该建模系统的开发有利于广大学者应用灰色系统进行建模和数据分析,促进其在应用领域的发展。     

基于NURBS的工程可视化建模技术

文中结合工程可视化的特点，着重于对其实现的基础技术——三维数字建模技术，提出了用NUM强进行建模的方法。从实用的角度讨论了几种方法的应用特点，并针对工程实际应用中的各种复杂形体，解决了如何有效地运用这些方法进行三维建模以及实现的若干工程可视化实际应用。     

An interactive agent-based system for concept-based web search

Search engines are useful tools in looking for information from the Internet. However, due to the difficulties of specifying appropriate queries and the problems of keyword-based similarity ranking presently encountered by search engines, general users are still not satisfied with the results retrieved. To remedy the above difficulties and problems, in this paper we present a multi-agent framework in which an interactive approach is proposed to iteratively collect a user's feedback from the pages he has identified. By analyzing the pages gathered, the system can then gradually formulate queries to efficiently describe the content a user is looking for. In our framework, the evolution strategies are employed to evolve critical feature words for concept modeling in query formulation. The experimental results show that the framework developed is efficient and useful to enhance the quality of web search, and the concept-based semantic search can thus be achieved.