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961.
自然灾害与区域经济可持续发展 总被引:4,自引:1,他引:3
运用系统工程理论,研究了自然灾害对区域经济持续发展的影响-对区域经济增长、产业结构、资源与环境及区域间经济联系与合作的影响,并对防灾救灾工作提出了建议. 相似文献
962.
1996年11月9日21时56分南黄海(北纬31°50′,东经123°06′)发生了MS61地震。本文分析了距震中290km的江苏省大丰市地震台电磁辐射观测仪在地震前后的观测资料异常记录情况,提出了一些认识,并进行了讨论。 相似文献
963.
有机锡化合物对水生无脊椎动物的毒性研究 总被引:3,自引:0,他引:3
通过不同层次水生无脊椎动物的毒理学研究,能更好地反映有机化合物的生态效应,以氯化三丁基锡(TBTCl)为例,结果表明,TBTCl对原生动物等5种水生无脊椎动物的半致死浓度(LC50)为25.65-355.63ppb,有明显的种特异性,TBTCl对河口轮虫种群净生殖率EC50为10ppb,影响平均寿命EC50为22ppb,根据浓度C及原生动物平衡种类数Seq进行回归,得方程Seq=11.87-1.8 相似文献
964.
高效液相色谱法分析水中痕量多环芳烃 总被引:14,自引:3,他引:14
本文利用高效液相色谱法测定水中痕量多环芳烃(PAHs)。以二氯甲烷作溶剂,超声提取水中痕量PAHs;甲醇、水作流动相,梯度淋洗,用程序可变波长荧光检测器测定。PHAs浓度为0.007=0.6μg·ml^-1范围时,线性相关系数均在0.9999以上;峰高、峰面积的相对标准偏差(n=10)分别为1.01-1.85%,2.00-3.94%;检测限(S/N=2)为3.1-23.0pg;实际水样的加标回收率 相似文献
965.
利用人工神经网络研究含硫芳香族化合物结构与毒性的关系 总被引:2,自引:0,他引:2
本文采用简单的化学基团描述符,运用人工神经网络研究了含硫芳香族化合物对发光菌的性构效关系,并与多元线性回归相比较,结果显示了人工神经网络处理非线性问题的优越性。 相似文献
966.
Field studies on 32P movement and P leaching from flooded paddy soils in the region of Taihu Lake, China 总被引:5,自引:0,他引:5
Xie XJ Ran W Shen QR Yang CY Yang JJ Cao ZH 《Environmental geochemistry and health》2004,26(2-3):237-243
Field experiments were done in two sites, Yixing and Changshu, Jiangsu province, China, to study P movement and leaching in flooded paddy soils. P movement in soil was investigated by using the KH2 32PO4 tracker method, and the amount of P leached from the soil layer in different depths was estimated by measuring P concentrations in the soil solution and saturated hydraulic conductivities in field. Determination was done about one month after P application. There was 46% and 42% of total 32P retained in the 0-5cm layer of soil in the Yixing site and in the Changshu site respectively. The 32P retained in the 25-30 cm layer was only about 1-2% of the total 32P added. Furthermore, 8.01% of 32P in the soil of Yixing site and 16.8% of 32P in the soil of Changshu site was lost from the layer 0-30 cm soil. The seasonal amounts of P leached from the top soil layer and from bottom layer are about 4.5-5.8% and 1.6-2.1% of the total P application, respectively. Changes of total P concentrations in soil solutions during rice growth showed that the fertilizer P applied before flooding of the paddy fields suffered a flash leaching loss and a slow leaching loss. We concluded that the fertilizer P could quickly move in the flooded paddy rice field and parts of it can enter into surface water and ground water. Unless the P application is well managed the risk of P loss and consequently environmental pollution exist. 相似文献
967.
Pollution survey of polycyclic aromatic hydrocarbons in surface water of Hangzhou, China 总被引:8,自引:0,他引:8
The concentrations of 10 polycyclic aromatic hydrocarbons (PAHs) were simultaneously measured for five times (July and November 1999–2002) in four water bodies of Hangzhou, China. To investigate possible sources of PAH contamination, sediments, soils, runoff water and atmospheric particles of the region were also analyzed for their PAH contents. The maximum levels of PAHs in the water bodies (34.4–67.7 μg/l) were found in July, while significantly lower PAH concentrations (4.7–15.3 μg/l) were measured in November. The contamination is substantial and it may have resulted in acute toxic effects on aquatic organisms. The measured PAH concentrations in sediments and soils (224–4222 ng/g), runoff water (8.3 μg/l) and air particles (2.3 μg/m3) are discussed in relation to concentrations and patterns found in the surface water bodies. Comparison of PAH levels in sediments and soils led to the conclusion that the erosion of soil material does not contribute significantly to the contamination of sediments. The atmospheric PAH deposition to water bodies in the city area of Hangzhou was estimated to be 530 tons/a, while the contribution of surface runoff water was estimated to be 30.7 tons/a. The ratios of selected PAH were then used to illuminate the possible origin of PAHs in the examined samples (petrogenic, pyrogenic). 相似文献
968.
Acclimation of anaerobic sludge degrading chlorophenols and the biodegradation kinetics during acclimation period 总被引:10,自引:0,他引:10
The acclimation of sludge from Hangzhou citrate factory and Hangzhou municipal wastewater treatment plant for degradation dechlorination of chlorophenols (CPs) compounds, and its biodegradation kinetics were studied in batch process with or without addition of sucrose. Three monochlorophenols (2-CP; 3-CP; 4-CP) and pentachlorophenol (PCP) were concurrently fed to different bioreactors. The parameters that were monitored included biogas production, biogas composition and chemical oxygen demand (COD). The results showed that acclimation with chlorophenol can increase the degradation activity of anaerobic sludge and degradation rate of chlorophenolic compounds, and reduce the lag time. Degradation dechlorination activity of the acclimated sludge strongly depended on sludge source, microorganism population and chlorophenol congener. 2-CP was more easily acclimated than 3-CP and 4-CP. Among the four tested compounds, 4-CP was the most difficult to be acclimated. The observed degradation rate with presence of sucrose was higher than that with absence of sucrose, suggesting that addition of the external carbon source can stimulate the formation of acclimated sludge which could effectively degrade chlorophenols. Kinetic equations of biodegradation of chlorophenols were also presented in this paper. 相似文献
969.
马兰黄土中与三氮有关的微生物的分布及其反硝化能力 总被引:1,自引:0,他引:1
选择关中盆地马兰黄土为研究对象,采用平板菌落计数法研究了与三氮转化有关的微生物在0~9 m剖面上的垂直分布.结果表明,剖面上氨化细菌、硝化细菌、反硝化细菌、固氮菌分别为克土106~1010、101~103、103~108、103~105个.在试验区剖面7 m处的土壤中存在着反硝化菌富集区,数量达克土108个.对此层位土壤进行了反硝化能力实验,结果表明,马兰黄土反硝化作用最适宜温度为22 ℃和37 ℃,碳源的存在可大大提高反硝化速率,但改变碳氮比对反硝化速率影响不大.在15 ℃、无外界供给碳源、硝酸根初始质量浓度为56 mg/L情况下,反硝化菌对硝酸根的降解作用符合方程y=-2.682 8x 60.979,回归系数R=0.960 9.该反硝化菌富集区的存在为研究包气带中三氮转化提供了重要信息. 相似文献
970.
我国印染废水处理技术的现状和发展趋势 总被引:65,自引:1,他引:65
按物理法、化学法和生物法分别评述了我国印染废水治理技术的现状,并提出了今后的发展趋势。 相似文献