A fragment constant QSAR model for evaluating the EC50 values of organic chemicals to Daphnia magna.

The quantitative relationship between the median effective concentration (EC50) of organic chemicals to Daphnia magna and the number of molecular fragments was investigated based on experimental EC50 values for 217 chemicals derived from the literature. A fragment constant model was developed based on a multivariate linear regression between the number of fragments and the logarithmically transformed reciprocal values of EC50. Functional correction factors were introduced into the model. The model was verified using an independent set of randomly selected data. The mean residual of the final model was 0.4 log-units. The robustness of the model was discussed based on the results of three jackknife tests.     

Trophoblast-like cells sorted from peripheral maternal blood using flow cytometry: A multiparametric study involving transmission electron microscopy and fetal dna amplification

Three monoclonal antibodies (MAbs) against trophoblast (GB17, GB21, and GB25) and flow cytometry were used to sort trophoblast-like cells (TLCs) from peripheral blood of pregnant women. Sorted TLCs were processed for electron microscopy and fetal DNA amplification of the Y-specific sequences from mothers carrying male fetuses. At the ultra-structural level, most of the nucleated cells had the morphology of leucocytes, suggesting maternal contaminants, and we did not find the characteristic features of the free inter-villous trophoblast cells. Nevertheless, polymerase chain reaction (PCR) analysis showed an amplification of Y-specific sequences in two out of three samples of sorted TLCs. These results suggest that besides the maternal leucocytes, sufficient trophoblast nucleated fetal cells can be obtained using cell enrichment by sorting. This sensitive method holds promise for non-invasive prenatal diagnosis of fetal sex and if sufficient Y(positive) nuclei are found, for the diagnosis of selected numerical chromosome abnormalities.     

冶金矿山清洁生产审计

通过对姑山矿生产现状的调查研究，确定审计重点为选矿车间，分析了选矿车间存在的问题，提出了清洁生产方案，对方案实施后的经济效益作了分析。     

在污染条件下生物的生态效应

主要就污染物对动物、植物及人体健康的危害，以及在污染条件下生物的适应与进化作一综述。     

Gold mining in Siberia and the Far East as a source of mercury contamination of the environment

ＩｎｔｒｏｄｕｃｔｉｏｎＳｉｂｅｒｉａａｎｄｔｈｅＦａｒＥａｓｔａｒｅｔｈｅｏｌｄｅｓｔａｎｄｔｈｅｒｉｃｈｅｓｔｇｏｌｄ ｍｉｎｉｎｇａｒｅａｓｏｆＲｕｓｓｉａ .Ｉｎｔｅｎｓｉｖｅｇｏｌｄ ｍｉｎｉｎｇｈｅｒｅｓｔａｒｔｅｄｉｎｔｈｅｂｅｇｉｎｎｉｎｇｏｆｔｈｅ 19ｔｈｃｅｎｔｕｒｙ(Ｖｙａｚｅｌｓｈｃｈｉｋｏｖ ,1963) .Ｆｏｒｔｈｅｍｏｓｔｐａｒｔｇｏｌｄ ｂｅａｒｉｎｇｏｒｅｓａｎｄｓａｎｄｓｗｅｒｅｐｒｏｃｅｓｓｅｄｗｉｔｈｔｈｅｕｓｅｏｆａｍａｌｇａｍａｔｉｏｎｍｅｔｈｏｄｆｏｒｇｏｌｄｅ…     

江苏小梅岭硅灰石矿床特征及其成因

江苏溧阳小梅岭硅灰石矿产于二叠系栖霞组硅质岩中，其成矿热液主要来自庙西花岩岩体。矿体以层状产出，矿石为不规则透镜体，方解石和硅灰石常常互层，常见有硅质岩核心。伴生矿物主要有透辉石、绿帘石、符山石、鱼眼石和萤石。根据x射线衍射分析研究，矿区内硅灰石均属三斜低温硅灰石，其a=-7．934，B0＝7．321，C0=7．068，红外光谱和差热分析表明，该硅灰石矿杂质含量较少。根据野外地质条件和理论反应式、反应曲线，小梅岭硅灰石矿形成于半封闭的体系，其形成温度和压力均属中等。     

单级与两级序批式反应器用于牛场污水处理的比较研究

对序批式反应器 (SBR)的特点进行了简要的介绍。研究了水力停留时间和有机负荷率对单级和两级SBR用于牛场污水处理时污染物去除率和出水水质的影响 ,并对单级和两级SBR的污水处理性能进行了比较。研究结果表明 ,当用单级SBR处理 10 0 0 0mg LCODCr的污水时 ,1d水力停留时间即可获得较好的处理效果 ,但出水中仍含有一定量的氨。两级SBR可使用较短的水力停留时间而获得较高的污染物去除率和较好的出水水质 ,并可通过硝化过程实现氨的完全的去除     

可发性聚苯乙烯废水处理工程的设计与运行

介绍了采用中和混凝 水解酸化 生物接触氧化 化学除磷工艺对可发性聚苯乙烯 (EPS)废水的处理工艺。在废水中的CODCr、TP、SS、NH3 N分别为 194 0mg L、112mg L、5 92mg L、2 3 6mg L的条件下 ,废水经过处理后 ,出水CODCr、TP、SS、NH3 N分别为 70mg L、0 38mg L、2 6mg L、0 32mg L ,均可达到《污水综合排放标准》中的一级标准 ,废水中CODCr、TP、SS、NH3 N的平均去除率分别为 96 4 %、99 3%、95 6 %、98 6 %。     

英国的人造伊甸园--现代设计改变荒废矿坑

伊甸园引来370万观众 不占用耕地资源,在寸草不生的荒废矿坑建造热带植物园的现代建筑,这不是神话,而是在英国已经建成的现代新景观伊甸园。伊旬园被称为世界最大的脚手架工程,2000年正在施工时,就有50多万人慕名前往观看这个新概念建筑,未及开放,投资人便获得了150万英镑票房收入。最初设计时估算每年有大约150万游客到伊甸园,投资人