基于高分一号遥感卫星的渤海湾悬浮泥沙时空分布反演

悬浮泥沙是评价II类水体水质的重要参数之一,近海岸水域悬浮泥沙对重金属、营养盐等具有一定的吸附作用,悬浮泥沙的分布特征在一定程度上反映着污染物的迁移和循环,因此研究悬浮泥沙对渤海湾建设和环境保护具有重要意义。为探究渤海湾水域悬浮泥沙浓度和分布的变化特征,利用高分一号多光谱卫星影像,通过采用波段组合的方式对悬浮泥沙含量指数反演提取,反演得到2019年9个月的渤海湾悬浮泥沙指数,分析发现渤海湾悬浮泥沙含量在冬季受季风影响较高,春季和夏季的时候渤海湾高浓度悬浮泥沙向近岸收缩,秋季悬浮泥沙分布格局有正在向冬季过渡的趋势,本文研究可为渤海湾的生态环境保护和工业开发提供重要的科学依据和参考价值。     

社区防灾空间体系设计标准的构建方法研究

针对社区防灾空间体系设计缺乏可依据的标准这一问题,立足于认知社区防灾空间体系,提出了划分社区防灾等级、确定防灾等级对应的防灾系统适宜性构成、制定社区各类防灾系统关键性指标等系列建议和研究方法,并在此基础上探讨了相应的设计策略。     

结合防灾的城市开敞空间规划研究——以无锡太湖新城为例

5·12汶川地震引发了时城市防灾规划建设工作的反思,提出了时城市各级各类开敞空间规划应具备抗震防灾功能、规模、服务半径等要求,并对技术指标进行了有益的探索.     

四川荣县矿山环境开采现状分析

从开采概况、灾害概况及污染概况等方面对四川荣县矿山环境进行了分析,针对性地对荣县矿山环境的恢复与治理规划问题提出了建议,以更好地保护矿山环境。     

武汉某湖泊底泥的机械脱水性能研究

通过测定污泥比阻值来评价污泥的脱水性能,探讨采用机械脱水的方法处理武汉某湖泊疏浚底泥的可行性和经济性。结果表明,底泥脱水性能良好,可以采用机械脱水的处理方法。CaO、PAC、FeCl3和PAM都可以进一步改善污泥的脱水性能,而CaO和PAC的处理效果更好,且PAC的成本更低。较佳的控制条件：温度为16～18℃,过滤压强为0．015MPa左右,PAC投加量为0．09％左右。采用机械脱水方式处理底泥,操作压强低、药剂投加量少、脱水效果好、经济可行。     

浅析建筑电气火灾原因及防范措施

结合建筑物火灾的发生,从设计、施工、用电管理等方面分析电气火灾发生的原因,对防范措施进行了探讨,并针对其危害性,提出了预防电气火灾的具体措施及对策,以减少国家和人民生命财产的损失。     

Composition, distribution, and potential toxicity of organochlorine mixtures in bed sediments of streams

Mixtures of organochlorine compounds have the potential for additive or interactive toxicity to organisms exposed in the stream. This study uses a variety of methods to identify mixtures and a modified concentration-addition approach to estimate their potential toxicity at 845 stream sites across the United States sampled between 1992 and 2001 for organochlorine pesticides and polychlorinated biphenyls (PCBs) in bed sediment. Principal-component (PC) analysis identified five PCs that account for 77% of the total variance in 14 organochlorine compounds in the original dataset. The five PCs represent: (1) chlordane-related compounds and dieldrin; (2) p,p′-DDT and its degradates; (3) o,p′-DDT and its degradates; (4) the pesticide degradates oxychlordane and heptachlor epoxide; and (5) PCBs. The PC analysis grouped compounds that have similar chemical structure (such as parent compound and degradate), common origin (in the same technical pesticide mixture), and(or) similar relation of concentrations to land use. For example, the highest concentrations of chlordane compounds and dieldrin occurred at urban sites, reflecting past use of parent pesticides for termite control. Two approaches to characterizing mixtures—PC-based mixtures and unique mixtures—were applied to all 299 samples with a detection of two or more organochlorine compounds. PC-based mixtures are defined by the presence (in the sample) of one or more compounds associated with that PC. Unique mixtures are defined as a specific combination of two or more compounds detected in a sample, regardless of how many other compounds were also detected in that sample. The simplest PC-based mixtures (containing compounds from 1 or 2 PCs) commonly occurred in a variety of land use settings. Complex mixtures (containing compounds from 3 or more PCs) were most common in samples from urban and mixed/urban sites, especially in the Northeast, reflecting high concentrations of multiple chlordane, dieldrin, DDT-related compounds, and(or) PCBs. The most commonly occurring unique mixture (p,p′-DDE, p,p′-DDD) occurred in both simple and complex PC-based mixtures, and at both urban and agricultural sites. Mean Probable Effect Concentration Quotients (PEC-Q) values, which estimate the potential toxicity of organochlorine contaminant mixtures, were highest for complex mixtures. Mean PEC-Q values were highest for urban sites in the Northeast, followed by mixed/urban sites in the Northeast and agricultural sites in cotton growing areas. These results demonstrate that the PEC-Q approach can be used in combination with PC-based and unique mixture analyses to relate potential aquatic toxicity of contaminant mixtures to mixture complexity, land use, and other surrogates for contaminant sources.     

黑龙江省新林—呼中地区水系沉积物地球化学特征及找矿意义

在新林—呼中地区森林沼泽-冻土景观区,开展1∶50 000水系沉积物测量,探讨该区水系沉积物中元素含量分布、元素组合特征和区域地球化学异常特征,为下一步划分成矿远景区,开展地球化学找矿提供依据。结果显示:该区具备中高温热液型Cu、Pb、Mo、Au多金属矿成矿条件;早白垩世二长花岗岩区和白音高老组火山岩区Cu、Pb、Zn、Mo、Au显著富集,强烈分异,是寻找Pb、Cu、Mo、Au多金属矿化(床)的有利地段;区域异常与燕山早期酸性侵入体密切相关,应是晚侏罗世—早白垩世岩浆侵入、喷发以及构造运动强烈作用的结果。     

不同生态护坡下水土保持效果动态变化研究

为研究不同生态护坡措施实施后其护坡效果随时间的变化情况,选取北京市昌平区朱辛庄水土保持示范基地内的4组不同护坡类型径流小区为研究对象,通过连续5 a的植被调查和人工模拟降雨实验研究,对各个护坡径流小区的植被状况以及产流和产沙数据进行了分析。结果显示:4种生态护坡实施后,随着时间推移,护坡植物种类会朝着当地土生植物种类发生演替,从而导致护坡的水土保持效果发生变化,每种生态护坡的效果各不相同;单一植物护坡容易受到植物演替规律的影响,而采用工程与植物措施相结合的护坡形式,水土保持效果则更为持久有效。研究成果可为今后生态护坡技术的推广应用提供借鉴。     

沉积物体系中甲烷水合物平衡温度、压力条件实验模拟

研究沉积物中甲烷水合物的平衡温度和压力条件，对认识甲烷水合物的稳定性以及对未来准确评价和利用甲烷水合物能源非常重要。在温度为270．9～278．2K、压力为2．47～4．31 MPa条件下，分别对平均孔径为53．2nm、27．2nm和15．5nm的沉积物体系中甲烷水合物的分解平衡温度和压力条件(即相平衡)进行了测定，结果表明，近自然沉积物的平均孔径大小会影响甲烷水合物的相平衡条件。相同温度条件下，纯水体系中甲烷水合物的平衡压力比在沉积物体系中的低；随着孔径的增大，甲烷水合物在相图中稳定区的面积逐渐增加，但当体系中温度降低到冰点以下或者沉积物孔径增大到超过60nm时，沉积物孔隙毛细管对甲烷水合物稳定性的影响非常小，与纯水中的重合或者接近。甲烷水合物在沉积物体系中的相平衡数据可以用经验热力学方程拟合，拟合结果能反映孔径大小与甲烷水合物平衡压力、温度条件的相互关系。图3表1参20