Effects of mid-trimester induced abortion on the subsequent pregnancy

The outcome of the pregnancy following (a) a mid-trimester termination of pregnancy (TOP) for fetal neural tube defect (NTD) (77 women=group 1); (b) mid-trimester TOP for fetal Down's syndrome (13 women=group 2); (c) delivery of a baby with NTD (119 women=group 3) was studied. The prenatal fetal loss was relatively high in all groups. In group 1 it was similar to that found in other studies after first trimester TOP, in group 2 it was associated with advanced maternal age and the unexpected finding in group 3 was not attributable to advanced maternal age. It is suggested that a previous NTD per se might increase the risk of fetal loss in the next pregnancy. A previous mid-trimester TOP for NTD was not associated with an increase in premature labour, small for dates babies or congenital abnormality in the next pregnancy, but there was a slight increase in the number of babies weighing less than 2500 g.     

焦化废水污染特征及其控制过程与策略分析

针对量大面广、成分复杂、具有典型的有毒/难降解工业有机废水特征的焦化废水,介绍了不同生产工艺的水质水量、污染物组成、有机污染物的生物降解特性及基于其特性的废水处理方法的选择;重点分析了以脱氮为目标的A/O、A2/O、A/O2、O/A/O工艺的特点,强调了生物流化床反应器的高效性;从溶解氧、温度、pH值、营养组成、污泥龄及有毒有害物质调控等方面讨论了焦化废水污染控制过程的影响因素,比较了不同工程工艺的技术特点与经济差异,对一些敏感性指标提出了控制策略,强调了技术创新与政策性补偿有助于解决行业环保问题的观点.     

云南省水电站开发对生态环境的影响及保护对策

概述了云南省水资源、水能资源和云南水电开发的现状，分析了水电开发对生态环境产生的主要问题和影响，提出了水电开发对生态环境的保护对策。     

大学校园中影视艺术教育的社会责任

影视艺术教育是对大学生进行综合素质教育的重要组成部分。作为旨在提高学生艺术素质的影视艺术教育,肩负着重要的社会责任,包括对影视艺术形式本身传承和发展的责任、历史教育和现实教育的责任、道德教育的责任、传承民族文化精粹的责任、展示科技发展水平的责任等。     

Prenatal application of fluorescent in situ hybridization (FISH) for identification of a mosaic Y-chromosome marker,IDIC(Yp)

An amniocentesis was performed at 13.3 weeks' gestation for advanced maternal age. A mosaic sex chromosome pattern was found: of 50 cells examined, 34 had a 45,X karyotype. In 14 cells with a modal number of 46, a recognizable Y was substituted by a small non-fluorescent marker. C-banding identified the marker as an isodicentric in 12 cells. In two cells, the non-fluorescent marker appeared to be monocentric and looked like a non-fluorescent del (Yq), but could have been an isodicentric Y with inactivation of one of the centromeres. Two cells with a modal number of 47 showed two copies of the monocentric marker. Fluorescent in situ hybridization with an alpha satellite Y-specific centromeric probe confirmed the Y-chromosome origin of the markers and allowed for more accurate prenatal diagnostic information.     

江西德兴矿集区土壤重金属污染分析

矿山开发必然对矿区及周边地区的环境造成污染。文章以江西德兴铜多金属矿山及矿集区为研究区,开展区域土壤的重金属污染研究。在德兴地区4 800 km2的范围内,系统采集土壤样品919个。同时,采用X荧光光谱法、等离子原子发射光谱法等现代测试技术,分析了土壤中重金属(As、Hg、Cd、Cr、Zn、Cu、Pb)的含量。样品中重金属As、Hg、Cd、Cr、Zn、Cu和Pb的含量变化范围分别为1.790~899,0.034~4.980,0.043~8.330,10~666,25~18 500,6~1 825,16~1 312 mg/kg。通过对样品的重金属元素含量统计分析和绘制等值线图,发现该区域土壤中存在不同程度的As、Hg、Cd、Zn、Cu和Pb重金属污染。污染区域主要分布在德兴铜钼和铅锌矿区、乐安河下游乐平附近的煤矿区、西北部的煤矿区以及南部的电化学厂附近。     

最小二乘支持向量机在臭氧浓度时间序列预测中试应用

将基于统计学理论的最小二乘支持向量机(LSSVM)方法试用于臭氧浓度时间序列预测.首先利用臭氧浓度时间序列资料重构了该混沌动力系统的相空间,然后沿着系统演化的相轨道用最小二乘支持向量机建立了臭氧浓度短时预测模型,并用上海市淀山湖站的臭氧观测资料做了提前1～8 h和提前24 h预报试验,结果显示这一模式能够较好地模拟臭氧浓度演化轨迹,提前1～8 h的预测精度均超过90%,提前24 h预报精度亦都在68%以上,预报效果较好.     

Enzymatic degradation of poly([R,S] β-hydroxybutyrate)

The synthetic analogue of a bacterially produced polyester, poly(-hydroxybutyrate) (PHB) was synthesized from racemic -butyrolactone using anin situ trimethyl aluminum-water catalyst. The polymer was fractionated into samples differing in molecular weight and isotactic diad content. The latter was closely related to degree of crystallinity. The biodegradation of these fractions were examined by monitoring mass loss over time in the presence of anAlcaligenes faecalis T1 extracellular bacterial poly(-hydroxybutyrate) depolymerase. The fraction with high isotactic diad tacticity content showed little or no degradation over a 50 hour incubation period, whereas the fraction of intermediate isotactic diad content degraded in a continuous steady fashion at a rate that was less than that for bacterial PHB. The low isotactic diad fraction underwent a rapid initial degradation, followed by no further mass loss. The presence of stereoblocks in the polymer structure of the various fractions was an influence on the degree of susceptibility towards degradation and is related to sample crystallinity.     

布袋式除尘器在电厂输煤系统上的应用

针对胜利电厂皮带输煤系统粉尘浓度高、污染环境、影响职工身体健康的问题，用布袋式除尘器替代原有的静电除尘器，并对布袋除尘器辅助系统进行了多处改进和完善，提高了运行的可靠性。投运后粉尘质量浓度由原来的18．3mg／m^3降低至1．68mg／m^3，除尘效率达到了98％以上。