空间目标碰撞预警摄动因素研究

针对解析筛选方法中摄动因素易造成漏报危险时间区间的问题,改进了时间筛选算法. 该方法在时间筛选中,增加了初始窗口修正,并在周期修正中考虑了偏心率摄动. 以2005年发生的空间目标相撞事件为例,在不同的预警时间区间中,讨论了摄动因素对几何筛选的影响,并对比了无摄动、原方法和改进的时间筛选方法得到的危险时间区间. 结果表明,摄动因素可有效降低几何筛选中由接近距离偏小造成错误筛除危险目标的风险,改进后的时间筛选算法比原方法能得到更为完整准确的危险时间区间.      

破碎筛分系统的改造

分析了导致锅炉运行状况不佳的原因,概述了破碎筛分工艺流程,提出了破碎筛分系统的改造措施.     

野西瓜苗对枸杞蚜虫的触杀活性测定

采用点滴法，测定野西瓜苗不同溶剂提取物、不同月份乙醇提取物、不同部位乙醇提取物对枸杞蚜虫的活性。结果表明，氯仿提取物、十月份乙醇提取物、籽的乙醇提取物的活性最高，48h的校正死亡率分别为86．39％、88．17％、91．56％。由此表明，野西瓜苗对枸杞蚜虫具有较强的触杀活性，为开发以野西瓜苗为原料的植物杀虫剂提供依据。     

Daily activity of the white-clawed crayfish,Austropotamobius pallipes (Lereboullet): a comparison between field and laboratory studies

The daily activity of the threatened crayfish, Austropotamobius pallipes (Lereboullet), was studied both in the field, through direct counts of active animals along a stream section, and in the laboratory, by means of actographs. In the field, crayfish were mostly found after dawn, with a slight but significant difference among seasons. In winter, only two specimens were seen to be active. Distinguishing among size classes, medium-sized crayfish were more abundant in spring and summer, while large ones mostly occurred in autumn. The former always concentrated their activity at night-time; to the contrary, larger specimens were more active late at night in spring and at dusk in autumn. Sex-ratio, analysed only in summer, was balanced throughout the 24h. Nocturnal activity, although differing among seasons, was similar in size classes, temperatures and sexes. In the laboratory, activity (evaluated as photo-cell interruptions) increased with temperature and occurrence throughout a 24-h cycle (the highest peak shifting from midnight to dusk). Only in the laboratory, a low peak occurred at dawn, but disappeared when a shelter was available. The interaction between the response of A. pallipes to temperature and its nocturnal habit is examined. Questions still remain on the adaptive value of the environmental factors influencing the cycle of freshwater decapods' activity.     

基于MC9S12XS128的自动电阻测试仪设计

本文以飞思卡尔公司的16位微处理器MC9S12XS128为控制芯片,用4×4矩阵键盘作为人与系统对话设备,用自带汉字库的带背光的12864LCD为显示器,设计了自动电阻测试仪。测试仪实现了100Ω、1KΩ、10KΩ、10MΩ四档位的精确测量,且在各档位间能实现自动切换;同时具有电阻筛选功能;测试仪还设计了自动测量电位器阻值随旋转角度变化的装置,能动态显示电位器阻值随旋转角度变化的曲线。系统性能稳定,测量精度高,具有相应的灵活性和实用性。     

产γ-氨基丁酸乳酸菌的筛选

从多种酸菜水中分离筛选出乳酸菌,利用乳酸菌将谷氨酸转化为GABA的脱羧作用,通过混合酸碱指示剂颜色变化,直观判断谷氨酸脱羧酶（GAD）活性,进而筛选出产GABA乳酸菌菌株BL2,并对其进行初步鉴定;同时,采用纸层析法进行定性分析,确定菌株BL2可将谷氨酸钠转化生成GABA.     

降解氰化物微生物的筛选

氰化物是一种毒性极大的物质，ＣＮ－浓度高将影响废水生化处理效果。对此，我们从太原煤气化公司生化站曝气池活性污泥中分离，筛选出高效降解ＣＮ－的细菌，共分离出２３个菌株。通过降ＣＮ－实验比较、筛选出６ｈ内降解率达８０％以上的菌株８个。最适作用条件为：温度２８℃，ｐＨ为７．２～８．５。其中９７０４００６号菌株的降解率可高达９０％以上。该菌株８ｈ内可使浓度在３０ｍｇ／Ｌ的含ＣＮ－废水降致０．５ｍｇ／Ｌ以下，达到国家废水排放一级标准。     

Optimization Model for Environmental Stress Screening of Electronic Components

1. INTroDUCTIONEnvironmelltal stress screening (ESS) is a technological process in which the latent defects inside electronicproducts are forced to transform into failures by proper environmental stresses, which are then discovered andeliminated. It is aimed to precipitate the costly early field failures of electronic products. The term ESS issometimes used as synonym with burn-in, but they are in fact two different processes. Though both of themhave the same goal, the major difference l…     

微生物絮凝剂产生菌的筛选及絮凝活性的测定

采用常规细菌分离纯化方法,从污泥和土壤中筛选出13株能产絮凝剂的菌株,培养48h后产生的絮凝剂对高岭土悬液的絮凝率均可达到70%以上.