植物叶钾离子渗出量在大气质量评价中的应用——Ⅱ.利用叶片K~+渗出量和含硫量监测大气SO_2污染的比较研究

以加拿大杨(Populus Canadensis)为材料,经熏气证实,SO_2浓度与叶片含硫量及K~+渗出量之间呈密切正相关。按污染指数(IPC)法和统计法(μ+s)划分四个污染等级,用以评价沈阳市SO_2污染,K~+渗出量法较叶片含硫量法更接近理化监测值。按95%置信度绘制预测图,经精度分析,K~+渗出量法较叶片含硫量法更为精确。     

高浓度CO2对红松根际及根外土壤微生物群落结构的影响

采用DGGE(Denaturing Gradient Gel Electrophoresis)技术,于2003年的7～9月中旬对高浓度CO2(700和500μmol·mol-1)处理下的红松幼苗根际和根外0～10 cm土壤微生物群落结构进行了研究.结果表明,大气CO2浓度升高对红松根际和非根际土壤细菌群落结构产生了较大的影响,主要表现为部分细菌物种的出现,或原有细菌数量的丰富以及原有物种的消失或其数量被削弱的现象,但主要建群种未变.     

公路可持续发展若干问题分析

根据可持续发展发展内涵的代际公平性、资源限制性、发展协调性和质量效益型发展要求，分析了湖北省公路发展现状，提出了“代际单元”概念，提出了考虑代际公平的决定性影响，对公路设计、施工和营运三个阶段中环境保护的实施进行了打分评价，得出了公路目前还远离可持续发展状态的结论，强调了公路实施可持续发展的要点。     

广东沿海牡蛎Cd含量的地理分布和时间变化

１９８９￣１９９３年对广东沿岸海域１４个观察站的牡蛎Ｃｄ含量进行了监测。结果表明，广东沿海牡蛎Ｃｄ含量存在着明显的地理差异，牡蛎Ｃｄ含量的地理分布基本上如实地反映了广东沿岸海域环境中Ｃｄ的地理分布状况；牡蛎Ｃｄ含量的季节变化明显，高值出现在秋季，低值出现在春季，牡蛎Ｃｄ含量的季节变化在很大程度上受控于牡蛎自身的生物条件；个别观察站牡蛎Ｃｄ含量的年际变化较大，但就整个广东沿海来说牡蛎Ｃｄ含量的年限变     

处理化肥厂造气废水新型催化剂的研究

利用合成的氧化还原树脂进行了实际废水的处理 ,取得了良好的效果 ,开辟了废水处理的一条新途径。     

全国2018~2019年秋冬季气象条件变化对PM2.5影响研究

本文基于WRF-CMAQ模型定量分析了气象条件变化对PM_2.5的影响.全国337个城市2018~2019秋冬季气象条件转差导致PM_2.5平均浓度同比上升约5.55%.24个省市气象条件同比转差，北京气象转差致使PM_2.5同比上升约3.66%.从重点区域来看，京津冀及周边“2+26”城市气象条件转差最显著，汾渭平原次之，长江三角洲（以下称长三角）基本持平，分别导致PM_2.5浓度同比上升约9.4%、8.3%、1.1%.“2+26”城市和汾渭平原气象条件在11月、1月、2月转差，10月、3月气象条件转好.长三角则10月、11月、3月气象条件转差；12月、1月、2月转好.“2+26”城市2018~2019秋冬季PM_2.5浓度同比上升主要为气象条件转差所致；汾渭平原PM_2.5同比变化较小，人为减排有效抵消了气象条件转差带来的不利影响；长三角PM_2.5浓度同比下降，与气象条件变幅小且污染排放较去年同期降低有关.     

室内空气中的甲醛检测及控制

随着人们对居室装修要求的不断提高,人造板及油漆等在室内装修中已经广泛使用,随之而来的是由于装修引起的室内空气化学污染问题,室内空气中有害化学物质对人们身体健康的危害也越来越大,其中甲醛对人体的危害尤为严重.室内空气中甲醛的检测及控制已经得到各发达国家和国内的高度重视,对甲醛的检测和控制技术的改进也成为社会各界普遍关注的问题.     

气相色谱法测定蔬菜中有机磷农药残留的前处理方法比较

采用液-液萃取、索氏提取和基质固相分散3种不同的方法对青椒样品进行前处理，用毛细管气相色谱法对处理后样品中的DDV、甲拌磷、甲基-对硫磷和马拉硫磷等农药残留进行测定，并对不同前处理方法的回收率和精密度进行比较。结果：3种方法的回收率和RSD相当，但基质固相分散操作较为方便简单、溶剂消耗量少。     

Cross-hybridization of the chromosome 13/21 alpha satellite DNA probe to chromosome 22 in the prenatal screening of common chromosomal aneuploidies by fish

In a routine application of commercially available centromeric DNA probes for the prenatal screening of common trisomies involving the autosomes 13, 18, and 21, and sex chromosomes, four cases of discrepancy between fluorescence in situ hybridization (FISH) results and follow-up cytogenetic analysis were observed from a total of 516 cases of amniocentesis. In three of these cases, the results were false negative, and in one false positive. In this case, amniocentesis was performed because of a positive triple test in a 34-year-old woman with previous infertility treatment. The alpha satellite DNA probe for chromosomes 13/21 revealed five signals in 50 per cent of uncultured amniocytes, while standard cytogenetic analysis showed a normal karyotype. FISH analysis on metaphase chromosomes demonstrated the location of the additional signal in the centromeric region of chromosome 22. This additional signal was also present in the centromeric region of chromosome 22 of the mother, providing evidence for a possible inherited polymorphism in chromosome 22 responsible for unspecific hybridization with the alpha satellite probe for chromosomes 13/21 in this case. The observed polymorphism in centromeric regions may contribute to unreliability of the use of the 13/21 alpha satellite probe for prenatal screening by FISH.     

Transabdominal villus sampling in early second trimester: A safe sampling method for women of advanced age

Transabdominal chorionic villus sampling (TA-CVS) was performed in 707 viable singleton pregnancies to exclude chromosomal abnormalities. Maternal age ranged between 36 and 49 years (mean 37·9 years); gestational age varied between 10·2 and 18·3 weeks (mean 13·3 weeks). In 639 women (90·4 per cent), a sufficient amount of chorionic tissue (⩾ 10 mg) was obtained after one needle insertion; in 66 women (9·3 per cent) two insertions were needed. An abnormal chromosome pattern was established in 19 cases (2·9 per cent). Vaginal bleeding or spotting within 28 days after TA-CVS occurred in 11 cases (1·5 per cent). The completed follow-up of 678 chromosomally normal pregnancies showed an overall fetal loss rate of 2·6 per cent before 28 weeks. The overall perinatal mortality was 0·9 per cent. When relating fetal loss to gestational age at TA-CVS, this was 6·6 per cent in women sampled before 12 weeks against only 1·8 per cent after 12 weeks. At the same time, the percentage of fetal loss occurring within 2 weeks following the procedure was 75 and 30 per cent, respectively. It is suggested that these data reflect the decline in spontaneous abortion rate during this particular period of pregnancy. It is concluded that TA-CVS is an effective procedure which, when performed after the natural decrease of fetal loss, appears to be a safe option for women of advanced maternal age.