长江中下游大洪水与中强地震的相关性分析

1998年 ,长江流域发生了类似 195 4年的百年一遇全江性大洪水 ,1999年长江又发生了较大洪水。在上述背景下 ,长江中下游地区是否会发生中强震 ,需要进行认真的探讨。初步研究结果表明 ,长江大洪水之后 3年内 ,鄂、湘沿江地区中强地震受长江大洪水的“耦合振荡”作用较大。     

姜的妙用

“冬吃罗卜,夏吃姜．不找医生开药方”,这话里说的姜,其营养是不能小看的。燃烧脂肪．不易发胖。生姜中的辛辣物质产生刺激作用．促进肾上腺素的分泌,加快新陈代谢和血液循环．并可以充分到达肢体的每一部分．使受凉或爱发凉的四肢末梢受暖发热．毛孔扩张．促进排汗．带走人体内多余的热量。如果体温下降1度．基础代谢能力就会减少12％。人体变暖．代谢增强,不用刻意去做什么就能成为不易发胖的体质。     

微囊藻毒素及其与其他环境污染物的联合毒性研究进展

微囊藻毒素(microcystins,MCs)是一种蓝藻代谢产物,在全球富营养淡水生态系统中广泛分布,高浓度的MCs不仅对水生生物造成负面影响,还会与水体中共存污染物发生相互作用,影响彼此在生物体内转化代谢和毒性效应.因此,开展MCs与多种环境污染物的复合污染对不同生物的毒性研究十分必要,其对水体复合污染风险评价和防控...     

基于集对可拓耦合算法的尾矿库安全综合评价

针对尾矿库安全综合评价中“定性定量评价尾矿库安全等级”和“客观描述尾矿库安全状态变化趋势”的要求,采用集对分析方法和可拓理论,利用可拓距计算原理,建立尾矿库集对可拓耦合安全评价模型和尾矿库集对势的计算方法。利用RSCIE权重计算方法确定尾矿库评价指标的权重,将基于集对可拓耦合算法的尾矿库安全评价模型用于尾矿库各安全等级集对可拓联系度的分析中,并基于最大隶属度原则确定案例中的尾矿库为正常库,其集对可拓联系度为0.040 6,安全状态的集对势为9.26。结果表明:该尾矿库的安全等级为正常库,且其安全状态发展趋势为弱同势,说明尾矿库的安全状况发展趋势为正常库的态势不强,且向不安全状态转变的可能非常大,应该加强该尾矿库的日常安全管理。这与实际情况相符合,有效验证了该评价模型的可行性和实用性。     

Estimating impacts of land use on groundwater quality using trilinear analysis

Groundwater is connected to the landscape above and is thus affected by the overlaying land uses. This study evaluated the impacts of land uses upon groundwater quality using trilinear analysis. Trilinear analysis is a display of experimental data in a triangular graph. Groundwater quality data collected from agricultural, septic tank, forest, and wastewater land uses for a 6-year period were used for the analysis. Results showed that among the three nitrogen species (i.e., nitrate and nitrite (NO_x), dissolved organic nitrogen (DON), and total organic nitrogen (TON)), NO_x had a high percentage and was a dominant species in the groundwater beneath the septic tank lands, whereas TON was a major species in groundwater beneath the forest lands. Among the three phosphorus species, namely the particulate phosphorus (PP), dissolved ortho phosphorus (PO ₄ ^3?? ) and dissolved organic phosphorus (DOP), there was a high percentage of PP in the groundwater beneath the septic tank, forest, and agricultural lands. In general, Ca was a dominant cation in the groundwater beneath the septic tank lands, whereas Na was a dominant cation in the groundwater beneath the forest lands. For the three major anions (i.e., F^?, Cl^?, and SO ₄ ^2?? ), F^? accounted for <1 % of the total anions in the groundwater beneath the forest, wastewater, and agricultural lands. Impacts of land uses on groundwater Cd and Cr distributions were not profound. This study suggests that trilinear analysis is a useful technique to characterize the relationship between land use and groundwater quality.     

Environmental monitoring and assessment of the water bodies of a pre-construction urban wetland

It is planned that the Dayanghan Wetland in China will be transformed into a national park but little is known about its current water quality and pollution status. Thus, we monitored the physical and chemical characteristics of the Dayanghan Wetland, which showed that the water quality was generally good. However, the chemical oxygen demand was more than double the reference value, which may be attributable to previous tillage for vegetable crops and other farmlands. In addition, nickel and chromium caused low-level pollution in the water bodies of the Dayanghan Wetland. The mean trophic level index and nutrient quality index were 39.1 and 2.69, respectively. Both indices suggest that the water bodies of the Dayanghan Wetland are in a mesotrophic state and that no eutrophication has occurred. The study would provide a precise report on the status of environmental quality of the water bodies of a typical pre-construction wetland for the administration and decision of the local government and the planning agent.     

Simulation of the migration and transformation of petroleum pollutants in the soils of the Loess plateau: a case study in the Maling oil field of northwestern China

We developed a coupled water–oil simulation model to simulate the migration and transformation of petroleum-derived contaminants in the soil of the Xifeng oil field. To do so, we used the HYDRUS-2D model, which simulates the diffusion, adsorption or desorption, and microbial degradation of petroleum-derived hydrocarbons in the soil–water system. The saturated soil hydraulic conductivity of petroleum-derived pollutants was 0.05 cm?day^?1, which is about 1 to 2 % of the soil moisture permeability coefficient. Our numerical simulation results show that spilled crude oil was mainly concentrated in the surface horizons of the soil. The organic pollutant concentration tended to be highest nearest to the pollution source. The pollutant migration was generally concentrated within the top 20 to 30 cm of the soil, with the maximum concentration in the top 5 cm of the soil. With passing time, the pollutant accumulation increased and the adsorption and degradation functions reached a dynamic balance with the input rate at depths greater than 30 cm below the soil surface. The oil-derived pollutants totaled 50 to 100 mg?kg^?1 under the dynamic balance condition, which occurred after 20 to 30 years. The petroleum-derived pollutant concentration in the loess soil was inversely correlated with the horizontal distance from the oil well, and the concentration decreased greatly at a distance greater than 40 m from the well.     

Observation of saltwater intrusion and ETM dynamics in a stably stratified estuary: the Yangtze Estuary,China

Spatial and temporal measurement data describing spring–neap variations of velocity, salinity, and suspended sediment concentration (SSC) in the North Passage Deepwater Navigational Channel (DNC) of the Yangtze Estuary, China, were obtained in the wet season of 2012. These data were collected in the middle of the DNC and apparently document the formation of a rather stable density stratification interface and salt wedge, especially during neap tides and slack waters. The convergent zone of residual currents, salinity transport, and sediment transport during neap and spring tides oscillates in the middle and lower reach of the DNC. It encourages the formation of a near-bed high-SSC layer, which favours siltation in the dredged channel. Both the near-bed gradient Richardson number and the bulk/layer Richardson number vary dramatically from around zero to several hundred from spring to neap tides. Stratification and turbulence damping effects near the estuarine turbidity maximum (ETM) area induce the upper half (near water surface) of the water body to be ebb-dominant and the lower part (near-bed) to be flood-dominant, which is a previously undocumented phenomenon in this region. These data reveal that the residual pattern of currents, salt flux and sediment flux are of critical differences in a stratified estuary, and that the salinity-induced baroclinic pressure gradient is a major factor controlling the vertical velocity structure. In addition, field observations indicate that the salinity and sediment transport of residuals generated by internal tidal asymmetry plays a dominant role in maintaining a stable density stratification interface near the estuarine front.     

免疫磁珠分离技术在环境病原微生物检测中的应用

介绍免疫磁珠分离技术的原理和操作步骤,分析其主要影响因素.介绍该技术在环境样品病原菌、原虫及病毒检测中的应用及研究进展.环境样品成分复杂,需经适当分离纯化处理再进行病原微生物检测,从而保证检测结果的可信性.免疫磁珠分离技术兼具免疫反应的特异性及磁性分离的快速性,能够有效分离纯化环境水样中的病原微生物,广泛应用于病原微生物的检测.     

我国流域水污染研究综述

本文阐述了现阶段我国流域水污染防治的研究成果,即学者根据不同流域的污染特点提出了不同的治理对策,主要是法律制度和法律理念方面的创新;流域立法的呼声日益高涨,提出了水污染防治立法应尊重流域特性,采取统一立法的模式.流域水污染问题的研究具有多元化、多样性的特点,今后的主要研究方向为构建流域管理体系、流域水权制度和生态补偿制度.