Pseudomosaic centric fission of chromosome 4 in amniotic cells

This paper describes a case of pseudomosaic centric fission of chromosome 4 detected in amniotic fluid cell culture. The pregnancy went to term and the newborn had a normal chromosomal constitution.     

关于建立地震灾害指标体系的研究：地震灾情的综合信息系统

建立地震灾害指杯体系,对全面、系统地反映灾情是十分重要的。本文对地震灾害指标和指标体系的定义及指标的类型、建立指标体系的基本原则及其结构、功能等进行了论述。     

煤矿安全目标管理成果评价的模型与方法

在简要介绍煤矿安全目标管理方法和目标体系的基础上,提出了确定安全目标管理综合目标值的ＧＭ（１,Ｎ）－ ＳＭＣＯ模型,用于对目标成果进行评价,并给出了某煤矿安全目标管理成果评价的应用实例     

应用UBET模拟环形件金属流动及毛坯尺寸优化

利用上限单元法(UBET)数值模拟了自行车飞轮外壳的成形过程.优化出模锻自行车飞轮外壳的圆环毛坯尺寸.研究了环形件金属的流动规律和过程.并且用实验验证优化出的毛坯尺寸.试验结果与优化结果基本吻合.     

整改煤气加热装置确保焦炉安全生产

长源(淮北)焦化有限公司在原有生产焦炭规模(40×104 t/a)的基础上,2003年又新建了一座20×104 t/a的焦炉,从动工到投产仅用了8个月时间.该工程上马快、工期短、急于投产,因此投产后煤气加热装置故障不断,严重影响了焦炉的正常加热和安全生产.     

污染水体底泥治理技术研究进展

水体底泥污染,是世界范围内的一个环境问题,污染物通过大气沉降、废水排放、雨水淋溶与冲刷进入水体,最后沉积到底泥中并逐渐富集,底泥中主要的污染物有重金属、营养元素、难降解有机物.目前底泥的治理方法有原位修复和异位处置,原位修复主要有掩蔽技术、淋洗技术;异位处置主要有卫生填埋、堆肥法、干式热处理;生物修复技术是既可用于原位修复又可用于异位处置的一种方法,具有投资少、见效快且没有二次污染的优点,是一种具有广阔应用前景的技术.     

Stability of alpine timberline ecotone on Taibai Mountain,China

--Landscape boundaries are always indicated by thevegetation boundaries. As an ecotone between closed forest andtreeline, alpine timberline may respond to global climate changessensitively. The stability of timberline and treeline depend notonly on climate change, but also on the interaction of both sidesof the ecosystems. Three natural boundaries existing in thetimberline transitional zone are recognized (1) timberline (upperlimit of closed forest zone); (2) treeline (upper limit of treeislands zone); (3) tree-species line (upper limit of individualtree growth). Paleobotanical and sedimentary evidences suggest thatthere were several times of climate fluctuation during the Holoceneperiod in this area. The timberline of Taibai Mountain must havemoved for four times on the millennium scale. Being a stochasticoscillation boundary, treeline appears in a semi-stable conditionon the century scale. The tree-species line is even more unstable,which appears in an unstable status on the decades scale. Thecomparison of the stability within several landscape boundaries,shed light on the sensibility of these communities to variousperturbation and environmental heterogeneity, i.e., herb community is the most sensitive one, which is followed by shrubs, and forestis the most stable one. Trees and shrubs can adapt to rocky andpoor soils. On the contrary, alpine herbs are able to adapt towetter and cooler soils. Finally, under a scenario of a temperatureof 1.5-4.5℃ increase, the present timberline will be relativelystable but treeline and tree-species line will move upward.     

Emission of landfill gas in Qingdao, China

ＥｎｖｉｒｏｎｍｅｎｔａｌＳｃｉｅｎｃｅｓ，Ｂｅｉｊｉｎｇ１０００１２，Ｃｈｉｎａ）Ａｂｓｔｒａｃｔ：ＡｓｔｕｄｙｏｎｌａｎｄｆｉｌｌｇａｓｅｍｉｓｓｉｏｎｉｎＱｉｎｇｄａｏ，Ｃｈｉｎａｗａｓｃａｒｒｉｅｄｏｕｔ．Ｔｈｅｒｅｓｕｌｔｓｓｈｏｗｅｄｔｈ...     

静电除尘净化球团竖炉烟气技术研究

介绍了球团坚炉的烟尘排放特性,分析研究了影响静电除尘器工作性能的主要因素,总结了静电除尘改造工程中技术改进经验和运行管理所取得的经验。