应变速率对中碳低温贝氏体钢强塑性的影响

摘要：为探索低温贝氏体钢的断裂行为,研究应变速率对低温贝氏体钢TRIP效应的影响,采用不同应变速率的拉伸试验对低温贝氏体钢的强塑性进行研究。利用扫描电镜（SEM）、透射电镜（TEM）及X射线衍射（XRD）等试验方法对低温贝氏体钢的微观组织、断口形貌及裂纹走向进行表征。结果表明,随着应变速率的提高,试验钢的屈服强度由771MPa上升至806MPa,抗拉强度由1554MPa上升至1606MPa,断后伸长率由13.5%下降至9.0%。主要原因是高应变速率拉伸引发的绝热温升抑制了残余奥氏体的马氏体相变,对试验钢塑性造成负面影响。     

缩短机械加工中零件等待时间的方法讨论

在机械制造系统中，零件在各工序间加工及流转，一般情况下许多工序难免存在零件等待加工的现象。为了提高系统的加工性能，本文利用现代仿真技术及排队论，通过优化工件在各相关工序的加工时间，从而消除工序中存在的工件等待加工现象。文章提出的方法还可用来预测机械制造系统的运行性能、比较各种可供选择的方案以及实现制造系统决策的优化。     

Good ergonomics and team diversity reduce absenteeism and errors in car manufacturing

Prior research suggests that ergonomics work design and mixed teams (in age and gender) may compensate declines in certain abilities of ageing employees. This study investigates simultaneous effects of both team level factors on absenteeism and performance (error rates) over one year in a sample of 56 car assembly teams (N = 623). Results show that age was related to prolonged absenteeism and more mistakes in work planning, but not to overall performance. In comparison, high-physical workload was strongly associated with longer absenteeism and increased error rates. Furthermore, controlling for physical workload, age diversity was related to shorter absenteeism, and the presence of females in the team was associated with shorter absenteeism and better performance. In summary, this study suggests that both ergonomics work design and mixed team composition may compensate age-related productivity risks in manufacturing by maintaining the work ability of older employees and improving job quality.     

新形势下加强学校思想政治工作的探索

主要从教育观念、基本规律和学校、家庭、社会三位一体的育人网络等方面，探索新形势下如何加强学校思想政治工作。     

破碎覆岩回采巷道临界宽度研究

为了有效控制破碎覆岩回采巷道变形,根据其赋存特征采用工字钢架棚支护技术,分析破碎覆岩普氏拱结构的形成原理和研究回采巷道临界宽度。针对破碎覆岩回采巷道具有围岩破碎、强度低和不具有可锚性等特点,采用普氏拱理论,计算回采巷道围岩压力;当棚梁工字钢最大正应力等于工字钢屈服极限时推导出破碎覆岩条件下回采巷道临界宽度计算公式。以106煤矿为工程实例进行分析,结果表明：破碎覆岩回采巷道的合理临界宽度为4.4m;增大支护强度和减小巷道高度可有效提高破碎覆岩回采巷道临界宽度;如果需要更大的巷道宽度,可通过降低棚间距或增大型钢型号方法实现。     

Time-series primitive static states for detailing work state and flow of human-operated work machine

This paper proposes a quantification method for a comprehensive work flow in construction work for describing work states in more detail on the basis of analyzing state transitions of primitive static states (PSS), which consist of 16 symbolic work states defined by using on-off state of the lever operations and joint loads for the manipulator and end-effector. On the basis of the state transition rules derived from a transition-condition analysis, practical state transitions (PST), which are common and frequent transitions in arbitrary construction work, are defined. PST can be classified into essential state transition (EST) or nonessential state transitions (NST). EST extracts common phases of work progress and estimates positional relations between a manipulator and an object. NST reveals wasted movements that degrade the efficiency and quality of work. To evaluate comprehensive work flows modeled by combining EST and NST, work-analysis experiments using our instrumented setup were conducted. Results indicate that all the PSS definitely changes on the basis of PST under various work conditions, and work analysis using EST and NST easily reveals work characteristics and untrained tasks related to wasted movements.     

Female sex pheromone components ofHeliothis peltigera (Lepidoptera: Noctuidae)

Ten compounds were found in the sex pheromone glands ofHeliothis peltigera (Schiff) and identified as tetradecenal, (Z)-9-tetradecenal, (Z)-9-tetradecenol, (Z)-9-tetradecenyl acetate, hexadecanal, (Z)-7-hiexadecenal, (Z)-9-hexadecenal, (Z)-11-hexadecenal, (Z)-11-hexadecenol, and (Z)-11-hexadecenyl acetate. Behavioral tests in a wind tunnel and subsequent trapping studies conducted in the field indicated that (Z)-11-hexadecenal and (Z)-9-tetradecenal are the main pheromone components ofH. peltigera. Addition of (Z)-11-hexadecenol to the binary blend did not enhance the capture of males ofH. peltigera, but it decreased the number of males of the sympatricH. armigera. Rubber septa impregnated with a mixture of 2 mg (Z)-11-hexadecenal + 1 mg (Z)-9-tetradecenal + 0.6 mg (Z)-11-hexadecenol are recommended for monitoringH. peltigera. Contribution from the Agricultural Research Organization (ARO), No. 2454-E, 1988 series.     

MDX1060型X-荧光分析仪的应用与实践

甘肃祁连山水泥股份有限公司从英国牛津仪器公司引进的MDX1060型X-荧光分析仪于2001年11月投入使用，经过2年的调试和维护，掌握了影响其测试稳定性和准确性的各种因素(包括样品制备质量、设备维护技术、工作曲线和测试操作水平等)及其克服这些因素影响的技术措施，从而实现了该公司生产原材料和生科、熟料化学组成CaO，SiO2，Al2O3，Fe2O3，MgO，SO3，K2O和Na2O的快速准确测定，为提高生料配料质量和熟料质量提供了可靠的技术参数。     

An Improved Procedure for Determining the Work of Adhesion for Polymer-Solid Contact

Force-balance experiments in conjunction with the Johnson-Kendall-Roberts (JKR) theory have been used to determine the work of adhesion between solid systems. It has been shown that deficiencies in understanding the deformation behavior can lead to erroneous results. A modified procedure for determining the work of adhesion by force-balance experiments and JKR theory using normal displacement behavior has been introduced to address these deficiencies. This procedure involves improved experiental and data analysis protocols and has been applied to give more precise work of adhesion values for PDMS poly(dimethylsiloxane)-PDMS, PDMS-F(fluorinated silicon) and PDMS-Si (silicon) systems. The work of adhesion determinations are consistently less than those estimated by contact angle measurements.     

焦炭颗粒的粒度分布及其微观结构研究

焦炭颗粒是生产碳石墨制品的主要原料，它的粒度组成、分布及其微观结构不仅对碳石墨制品的机械性能和理化性能有一定的影响，而且还直接影响到各生产工序的成品率．为此，主要对粉碎后几种焦炭颗粒的粒度组成、分布及其微观结构进行了研究．并通过分析，确立了焦炭颗粒的粒度组成及其分布规律与粉碎方式和焦炭强度之间的内在关系．