齿形零件的冷摆辗成形

介绍了摆辗成形工艺的基本原理,综述了齿形零件冷摆辗精密成形和摆动辗压设备研制的概况.指明用压力加工方法,特别是冷摆辗工艺.加工精密齿形可提高零件机械性能,节能节材.     

Assay of some volatile compounds in human exhalation

ＡｓａｙｏｆｓｏｍｅｖｏｌａｔｉｌｅｃｏｍｐｏｕｎｄｓｉｎｈｕｍａｎｅｘｈａｌａｔｉｏｎＱｉｎＴａｏ，ＸｕＸｉａｏｂａｉＲｅｓｅａｒｃｈＣｅｎｔｅｒｆｏｒＥｃｏＥｎｖｉｒｏｎｍｅｎｔａｌＳｃｉｅｎｃｅｓ，ＣｈｉｎｅｓｅＡｃａｄｅｍｙｏｆＳｃｉｅ...     

Progress in the research on aquatic environmental nonpoint source pollution in China

ＰｒｏｇｒｅｓｉｎｔｈｅｒｅｓｅａｒｃｈｏｎａｑｕａｔｉｃｅｎｖｉｒｏｎｍｅｎｔａｌｎｏｎｐｏｉｎｔｓｏｕｒｃｅｐｏｌｕｔｉｏｎｉｎＣｈｉｎａＢａｏＱｕａｎｓｈｅｎｇ，ＭａｏＸｉａｎｑｉａｎｇ，ＷａｎｇＨｕａｄｏｎｇＩｎｓｔｉｔｕｔｅｏｆＥｎｖｉｒｏ...     

成组切边模的设计

提出了成组切边模设计的观点,并结合为企业实施成组切边模的实践,介绍了成组切边模设计的步骤、方法和成组切边模标准。     

关于高校环境类专业本科教学的思考

论述了从培养目标、课程设置、教学方法与实践等方面培养高素质复合型的环境类专业的本科生，以满足社会需求，并为环境类专业本科教学改革提供参考。     

机动车排出物对人体健康危害的研究

运用基因、ＤＮＡ、染色体，细胞和整个动物为终点的远期危害测试系统，对各类机动车排出尾气的有机提取物的致突变性及潜在致癌性进行了评估，同时运用流行病学方法对接触人群进行调查，结果表明：（１）柴油车，助动车的颗粒有机提取物包含１００多种化学物，（２）Ａｍｅｓ、ＵＤＳ微核及ＳＨＥ细胞恶性转化试验为阳性结果，具有突变性及致癌性。（３）它们能使人胚细胞形成转化灶并发现其中的ｃ－ｍｙｃ，ｐ２１及ｂｃｌ－２表达     

高强铝合金超塑挤压成形

主要介绍了工业牌号高强铝合金在供应态或经简单预处理后在通用油压机上超塑成形的实例,并分析探讨了非理想组织材料超塑成形中微观组织的变化。     

Atmospheric pollution in Beijing, China, as recorded in sediments of the Kunming Lake

The fluxes of heavy metals and magnetite, a fly-ash component, from coal burning, to sediments of the Kunming Lake in Beijing have increased measurably over the last fifty years. Ages were introduced to the sediment strata through Pb-210 geochronologies. Even with a doubling of coal usage by the year 2000, the anthropogenic metal fluxes will still be less than those recorded in metropolitan Tokyo and U.S. lakes.     

管材的冲切加工

此文系统介绍了管材冲切加工的工艺及模具设计,对常用圆断面管材的各种冲切工艺,如端口平面冲切、型面冲切等进行了探讨;分析了管材冲切加工中存在的主要问题;就如何提高冲切质量提出了行之有效的解决办法。     

Effect of domestic sewage on growth of phytoplankton-mathematical model

A mathematical model relating to the change in phytoplankton biomass in the period of growth and nutrient concentration in the media was proposed on the basis of the Monod equation and was testified by simulation experiments. Analysis of the experiment data showed that: the half-saturation constants for growth Kp (μmol/L) for Skeletonema, Chaetoceros and Prorocentrum were 5.52, 1.90 and 0.46, respectively; the balance between stimulation of nutrients and the inhibition of some other materials was found in the effect of domestic sewage on algal growth and the stimulation played a leading role; domestic sewage was more stimulative on dinoflag-ellate than on diatom and chlorophyte when the assemblage of the algae was cultured. The experiment suggested that mathematical model reasonably explained the characteristics of phytoplankton growth in different nutrient conditions and was worthy to be further improved for eutrophication prediction in off-shore water.