MODELING METHOD OF 4D INFORMATION MODEL FOR COOPERATIVE DESIGN OF MECHANICAL PRODUCTS

The continuous developing features in the design of mechanical product and based on 3D entity model is aimed at, and the extension of the 4-dimensional model with the process of designing, the knowledge described model on the level of semantic understanding and summarizing the designing process and the way of discovering knowledge from multi-information model are studied. On the basis of designing the broad sensed collaborative system, through discussion of the relationship between the implicit knowledge of the users and the designing knowledge as well as commanding all the designing links, taking advantage of the way of concluding and deducting in the concept of the designers, the synthetic knowledge unit formed in the dynamic process from the conception design to the last design is schemed out, and the knowledge discovered principle in the dynamic designing process of the mechanical products and the key technology in its implementation under the milieu of network is brought forward.     

Predictors of supportive coparenting after relationship dissolution among at-risk parents.

Supportive coparenting after relationship dissolution is associated with increased father involvement which can buffer against the negative effects of parental relationship dissolution. Low-income, at-risk families are much more likely to experience relationship dissolutions; hence, supportive coparenting after dissolution is particularly important in these families. We examined whether relationship (commitment and quality) and child (difficult temperament and gender) characteristics predicted initial levels of, and change in, supportive coparenting after relationship dissolution in the Fragile Families and Child Wellbeing Study (N = 1,603). We used structural equation modeling of latent growth curves to examine four time points collected at the focal child's birth and first, third, and fifth birthdays. Ninety-percent of the mothers had nonmarital births, and about three-quarters had a high school diploma or less education. Overall, supportive coparenting decreased over time. Mothers in more committed relationships prior to the dissolution initially had significantly lower supportive coparenting. But over time, mothers who had been in more committed relationships increased in supportive coparenting. Mothers who had been in higher quality relationships prior to dissolution initially reported more supportive coparenting. At each time point, if a mother was romantically involved with a new partner, she reported significantly lower supportive coparenting compared to mothers who were single. With regard to child characteristics, mothers who reported their child as more difficult had significantly lower initial supportive coparenting. Similar results for fathers are discussed. Overall, the relationship characteristics of parents were important predictors of supportive coparenting both initially and over time. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

“数字图像处理”课程教学实践与探讨

数字图像处理是信息类专业重要的本科专业课程之一。在为我院本科生讲授的数字图像处理课程实践中,我们尝试融合多种教学手段,提升课程教学效果。本文结合前期教学实践,从可视化教学手段、知识关联比较、理论结合实践、双语教改和教学大纲改进等方面介绍在该课程教学方面的一些探索和体会。     

汶川地震的6区域模型加速度峰值衰减关系

利用加速度记录直接拟合衰减关系时,几乎所有现行文献都采用圆模型,以震中距或震源距为观测点坐标位置的唯一统计量。对于长断层的大震而言,等震线的圆模型假设和实际等震线图存在严重的偏差,为修正这种偏差,作者曾提出了4区域的椭圆模型,但是该模型忽略了断层长度垂直范围的2个区域,导致其等震线形状没有沿着断裂方向发散开的趋势。且不能反映破裂方向对短轴衰减的影响。该文提出的加速度衰减关系的6区域模型,通过过断层方向和过断层两端点且垂直于断层6条分割线,将地震记录观测点位置分为6个区域,通过研究沿分割线方向的衰减关系得到地震动衰减与衰减路径所处区域的相关性。以汶川8.0级地震为例,说明模型下的6条衰减关系,各自代表的物理意义以及汶川地震地震动峰值加速度衰减的区域特性。在拟合精度上,该模型较圆模型有大幅提高,比4区域椭圆模型略高,在反映地震动区域特性上,比4区域模型更加细致的反映了断层破裂方向效应和上下盘效应。     

深水水基恒流变钻井液流变特性研究

水基恒流变钻井液是一种适用于深水钻井作业的新型工作流体,目前关于该体系的报道较少。通过对一定温度压力下钻井液性能的检测以及流变模型分析,研究了水基恒流变钻井液的流变行为,并初步探索了恒流变机理。结果表明,在0.1～35.4 MPa范围内,当温度从4℃升高到65℃,黏度计读数φ₆/φ₃、动切力、塑性黏度等流变参数的变化幅度较小,分别在10～13、9～12、13～18 Pa及15～22 mPa·s范围内,且φ₆与φ₃读数随温度呈“U”型分布;在温度压力组合条件下,拟合经验流变方程的相关性排序为:宾汉塑性≈幂律＜卡森≈赫-巴≈罗-斯模型,其中双参数卡森模型的相关系数较高,且表达式简洁,适于描述水基钻井液的恒流变特性;以卡森模型为初始方程,引入T/P因子建立了高预测精度的动力学流变方程f（T,P,γ）,相对误差平均值为7.19%±4.07%,偏差极大值集中在100（ r/min）/65℃;分析了关键处理剂的分子形貌、结构及其与黏土片层的缔合作用,提出了基于分子形态的定性构效假设,揭示水基钻井液的流变稳定性本质。      

2.25Cr-1Mo钢焊接接头蠕变后焊缝中 M6C碳化物的析出位向关系

本文用透射电镜研究了２．２５Ｃｒ－１Ｍｏ钢焊接接头蠕变后焊缝中的Ｍ６Ｃ碳化物。结果表明,高温长期蠕变促进了Ｍ６Ｃ的析出长大,从焊缝内析出的Ｍ６Ｃ与α－Ｆｅ铁素体间存在Ｎ－Ｗ位向关系,即：（１１１）Ｍ６Ｃ∥（１１０）ａ「０１１）Ｍ６Ｃ∥「００１」ａ。文中还讨论分析了其他两种取向关系：（１１１）Ｍ６Ｃ∥（１１０）ａ;「１０１」Ｍ６Ｃ∥「１１１「ａ及（１１１）Ｍ６Ｃ∥（１１０）ａ;「１１２」Ｍ６Ｃ∥「１     

浅谈移动通信CRM系统建设

客户关系管理CRM (CustomerRelationshipManagement)是近年在竞争环境下出现的新的增值服务。该增值业务对客户需求进行科学的分类管理 ,提供个性化服务 ;管理好客户资源 ,控制客户流失 ,留住大客户 ;掌握用户信誉度 ,控制销售进程 ,防范经营风险。形成以“客户为中心”的经营理念 ,是一种旨在改善企业与客户之间关系的新型管理机制 ,将推动企业最大限度的利用其与客户有关的资源 ,实现企业从市场营销到销售到最后的服务和技术支持的交差立体管理     

An analysis for AlGaN/GaN modulation doped field effect transistor using accurate velocity-field dependence for high power microwave frequency applications

An analytical model of Al_0.15Ga_0.85N/GaN modulation doped field effect transistor (MODFET), which uses an accurate velocity field relationship and incorporates the dominant effect of piezoelectric polarization induced charge at the AlGaN/GaN interface is presented. The effect of traps has also been taken into account. The calculated DC characteristics are in excellent agreement with the measured data. The model is extended to predict the microwave performance of the device. High current levels (>500 mA/mm), large transconductance (160.83 mS/mm) and a high cutoff frequency (9.6 GHz) have been achieved analytically and are in close agreement with the experimental data.     

一种基于交通视频的摄像机标定方法

介绍了一种线性模型下的摄像机标定方法。在获取交通视频的基础上,利用实际路面上的参照物和图像处理的基本知识抽象出交通视频中的像素行和路面实际距离之间的几何模型,对几何模型进行解析,得到视频图像上像素行和实际路面的距离映射关系。试验表明,该方法能够较好地实现图像上像素行到路面实际距离之间的转换。