稀土Y掺杂对Mg-3.0Zn-0.6Zr合金热压缩变形性能的影响

研究了质量分数为1%稀土Y掺杂对Mg-3.0Zn-0.6Zr合金在变形温度为523~723 K、应变速率为0.001~1 s-1范围内的热压缩变形性能的影响。基于动态材料模型建立的加工图,借助光学显微镜、扫描电镜和X射线衍射仪等设备,结合流变特征、微观组织结构演变,分析了Y添加对合金热变形机制及工艺参数的影响。结果表明,流变应力受变形条件影响较大,随变形温度的降低或应变速率的升高而增大;Y掺杂对流变曲线变化趋势影响较小,而对应力水平影响较大,各变形条件下均有不同程度提高,最大增幅约40%。另外,Y添加扩大了功率耗散区域,功率峰值约增大22%并转移至673~723 K、0.1~1 s-1附近,失稳缩至523~723 K、0.001~0.01 s-1的马鞍形区域,加工图给出的最优加工参数由高温低应变速率转移至523~723 K、0.1~1 s-1附近。     

千米深井大采高采场围岩应力分布规律数值分析

煤矿深部开采的应力集中异常突出,以唐口煤矿1305工作面为例,利用FLAC3D有限差分软件对千米深井大采高采场围岩应力分布规律进行数值分析。模拟结果表明:1305工作面回采时,在采空区四周煤体内形成对称的"双肺"状支承压力影响区;随着工作面推进,采场支承压力峰值及采空区上覆岩层破坏高度逐渐增大,工作面见方后,采空区顶板破坏高度与超前支承压力峰值变化趋于稳定,支承压力最大峰值约为72MPa,应力集中系数k为3.0;工作面煤壁前方与采空区两侧煤体内支承压力峰值随工作面推进向深部转移,且支承压力影响范围逐渐增大,压力峰值与工作面煤壁之间的距离基本保持在8~15m范围内。     

基于硅基液晶拼接的高对比度动态星模拟器光学系统

针对基于硅基液晶(LCOS)拼接技术的动态星模拟器对比度低,无法在星图识别过程中为星敏感器提供全部有效目标的问题,提出通过抑制光学系统杂散光来提高LCOS拼接动态星模拟器对比度的方法,讨论了偏振度对于杂散光的影响,并推导出入射角与偏振度的函数关系。设计了抑制杂散光的光学系统,该系统包括利用复合抛物面聚光器(CPC)结合望远系统组成照明光源,配合多棱镜的1/4波片和视场角不小于11°的准直光学系统。在截止频率为60lp/mm,视场角小于±5°的情况下,该准直系统的调制传递函数(MTF)大于0.7。实验显示:该高对比度LCOS拼接动态星模拟器的星间角距误差小于18″,相对于传统型的星模拟器杂散光降低了2.38倍,其在保证精度的条件下,降低了动态星模拟器的背景噪声,提高了动态星图的可识别率,基本可以满足星敏感器在多星等条件下的对精度和动态特性的需求。     

涤棉针织物分散/活性一浴一步法染色工艺

通过试验，优选出适合弱碱性与中性条件下一浴一步法染涤棉混纺针织物的染料和染色工艺。ERD系列分散染料较适合一浴法碱性浴染色，使用β-环糊精有增深作用，且匀染效果明显。部分B型染料在中性条件下比在弱碱性条件下的K／S值高。     

导航仪上装海量物理点的方法

本文通过几款软件的应用,能够把工区内大量的物理点转换成Garmin导航仪兼容的img矢量地图,再上装到导航仪里,从而解决了因导航仪内存小、上装物理点数量太少而给野外生产带来的麻烦。     

A new one parameter viscosity model for binary mixtures

The Grunberg & Nissian equation with one parameter is widely recommended in the viscosity calculation. However, it is demonstrated that this equation fails to generate satisfactory results for size‐asymmetric mixtures containing large and small molecules. In this work, a new one parameter viscosity model for binary mixtures has been developed on the basis of Eyring's absolute reaction rate theory and the Flory‐Huggins equation. The concept of molecular surface fraction is introduced for modeling liquid mixture viscosities. The viscosity calculations of the new equation are compared with the Grunberg & Nissian equation for a broad range of chemical mixtures including 527 binary systems (containing 63 binary ionic liquid cosolvent systems) and total 17,268 viscosity points. The new equation was found to have an improved performance over the frequently employed Grunberg & Nissian equation, especially for size‐asymmetric mixtures containing large and small molecules. © 2010 American Institute of Chemical Engineers AIChE J, 57: 517–524, 2011     

历史地形图的纠正与拼接方法的研究

历史资料数字化存档可以很好保护历史地形图资料,但处理过程面临着数据量大、不易校正、难拼接等问题。我院采用新的方法,将历史资料扫描后,利用有限元方法进行纠正,批量裁剪为统一大小,利用MrSID方法压缩拼接,很好地解决了这一问题。     

运用SW6进行双管板换热器管板的计算

由于ＳＷ６－９３（ＳＷ６－１９９８）软件包没有双管板换热器管板的计算模块，因此在设计计算时，我们将双管板换热器分成几个单管板换热器进行计算。几年来设计了数十台固定双管板换热器（卧式、立式）和Ｕ形管双管板换热器，下面介绍分解模式。     

Using self-organizing maps to model turnover of sales agents in a call center

This paper proposes an approach for modeling employee turnover in a call center using the versatility of supervised self-organizing maps. Two main distinct problems exist for the modeling employee turnover: first, to predict the employee turnover at a given point in the sales agent's trial period, and second to analyze the turnover behavior under different performance scenarios by using psychometric information about the sales agents. Identifying subjects susceptible to not performing well early on, or identifying personality traits in an individual that does not fit with the work style is essential to the call center industry, particularly when this industry suffers from high employee turnover rates. Self-organizing maps can model non-linear relations between different attributes and ultimately find conditions between an individual's performance and personality attributes that make him more predisposed to not remain long in an organization. Unlike other models that only consider performance attributes, this work successfully uses psychometric information that describes a sales agent's personality, which enables a better performance in predicting turnover and analyzing potential personality profiles that can identify agents with better prospects of a successful career in a call center. The application of our model is illustrated and real data are analyzed from an outbound call center.     

哥本哈根气候变化大会与中国涂料工业的发展

回顾了国际社会在应对气候变化方面的历史里程,重点介绍了哥本哈根气候大会的意义,简单介绍了我国政府应对气候变化方面的立场和主张,对于碳减排等基本概念做了介绍。最后结合我国涂料行业的实情,提出一些建议,希望能推动本行业在减少二氧化碳排放量方面做出一点贡献。