汶川地震特大型滑坡分布特征研究

2008年"5.12"汶川特大地震引发了数以万计的滑坡、崩塌、危岩等次生地质灾害,对灾区人民生命财产造成了惨痛损失.尤其是破坏面积大、危害范围广的特大型滑坡,给人们生命财产造成了巨大灾难,而且潜在危险性仍然存在.笔者通过实地调查、资料查阅等方式搜集统计了汶川地震区的特大型滑坡并对其分布特征作了较为全面的归纳总结和分析研究.     

桥墩底部岩溶对其上层围岩稳定性影响的数值研究

本文运用RFPA系统的强度折减版以清水大桥5号断面为背景对桥墩底部溶洞区对其上部围岩稳定性的影响进行了数值分析研究。研究结果表明:岩:容对其上层围岩的影响范围随着深度的增大而变大;破坏效应带主要是在垂直于自由面的溶洞两侧;对多溶洞而言,应力主要集中在两溶洞破坏效应带之间的区域,并且主要在此发生破坏,而在其内部效应带之间则比较稳定。     

忠-武输气管道巴东野三关石马岭危岩特征及防治方案论证

近年来忠-武输气管道山区段发生了多起危岩坠落冲击管道的事件,已经严重威胁到输气管道正常运行.笔者根据恩施石马岭危岩的发育特征,对石马岭危岩体治理方案进行论证,比较了危岩清方 锚固方案和管道护盖方案,根据本段管道工程所处地形地质条件,认为危岩清方 锚固为优选方案.     

公路沿线危岩崩塌风险定量评估——以甘肃S306沿线磨石咀崩塌为例

危岩崩塌是山区常见的不良地质现象,严重威胁着山区公路交通运输安全和城镇居民生命财产安全。以甘肃S306省道地质灾害较为发育的礼县段的磨石咀崩塌为例,借鉴国际地质灾害风险评估和管理体系,通过野外调查并结合交通流量调查对磨石咀崩塌进行定量风险评估。公路沿线危岩崩塌风险评估流程大致包括确定评估范围、危险性及危害后果分析、风险评估以及风险管理等方面。对磨石咀崩塌的评价结果为个人最大风险P(LOL)=6.30×10-9/年,在容许风险范围之内。最后针对公路沿线危岩崩塌提出了风险减缓措施。     

倾斜工作面底板破坏深度计算方法研究

煤层倾角是影响底板破坏带深度的一个重要因素,为深入研究煤层倾角对底板破坏带深度的影响,采用断裂力学理论建立了煤层倾角对底板破坏带深度影响的计算模型,得出由于煤层倾角的存在,倾斜工作面上部破坏带深度小于下部破坏带深度。收集我国大量的突水案例与煤层倾角统计数据,以及破坏带深度与煤层倾角统计数据,从突水案例数据可以看出倾斜工作面下部由于底板破坏造成的突水次数明显多于上部,从破坏带深度与煤层倾角变化趋势可以看出随着倾角增大破坏带深度也在增大。统计得到数据的结论与应用断裂力学模型分析得到的结论一致。最后对建立的破坏带深度计算模型井下质量检验,检验结果显示该计算模型的精度较高,符合现场应用的要求。     

南岸村采石场矿山崩塌稳定性及防治措施分析

采石场矿山边坡开挖后容易形成大量的危岩崩塌地质灾害,矿区开采面大部分暴露于路面视野范围之内,造成很大的视觉影响。通过对崩塌区地质灾害的调查,结合所收集的地质资料,分析了崩塌地质灾害的形成机制以及危害性,并通过Rockfall软件对危岩崩塌进行数值模拟分析,确定危岩滚动特征,为崩塌灾害防治提供依据。     

“岛礁环境装备适应性研究”专栏征文通知

<正>一专栏简介随着现代科学的迅速发展与陆上资源日益匮乏,海洋开发和利用在国民经济中所占地位越来越高,"海洋强国"、"海上丝绸之路"战略相继提出,海洋以其丰富的资源和特殊的战略地位受到广泛关注。岛礁是"一带一路"的重要陆上基地,也是海洋资源开发的重要组成部分。岛礁环境的突出特点是高盐雾、高温、高湿、强台风、暴雨、强烈日光辐射、海洋生物种类繁多等,是我国最为严苛的腐蚀环境,极易发生腐蚀、老化以及生物污损等,对材料、装备和设施造成的破坏不容忽视,已严重影响了各类装备与设施     

洱海东区湖滨带现状及生态修复

洱海是云贵湖区的一个重要淡水湖泊.近年来由于人类活动干扰的加强,造成洱海水质恶化、水生生态环境受到破坏,尤其是作为湖泊保护屏障的湖滨带,其生态结构破坏严重、生态功能退化,急需进行生态修复.针对洱海湖滨带的现状和主要环境问题进行了较为详细的分析,探讨了洱海湖滨带生态修复的设计分区、工艺流程和设计内容,提出了洱海东区湖滨带生态修复方案.     

基于改进Green-Ampt降雨入渗模型的花岗岩风化带边坡稳定性分析

为研究持续降雨对花岗岩风化带路堑边坡稳定性的影响,选取赣南安远至定南新建高速公路定南段花岗岩风化带路堑边坡建立地质模型,通过室内试验、资料统计分析等手段获取该边坡各层岩土体的物理力学参数,并结合区内实际强降雨工况,采用考虑排水的改进Green-Ampt降雨入渗模型,分别利用极限平衡法和强度折减法数值模拟方法对不同降雨工况下该边坡的稳定性和变形破坏模式进行分析。结果表明:随着降雨的持续,该花岗岩风化带岩土体边坡的稳定性系数逐步降低,工况一条件下降雨20 d或工况二条件下降雨18 h后,边坡的稳定性系数小于1;边坡坡体破坏从坡脚逐步向上延伸,并在坡体表面形成潜在的滑动面,而后台阶处也逐渐破坏;整体而言,该边坡的破坏模式为坡面冲刷和浅层剪切滑移破坏,高应力区集中在边坡坡脚处和各台阶处,短时强降雨情况下该边坡可能会发生整体滑移破坏。     

解决大型城市生活垃圾卫生填埋场库区施工难题探索

文章通过对大型城市生活垃圾卫生填埋场库区施工难题的分析,阐述了垃圾填埋场库区工程施工地下水丰富地区如何使用纳基膨润土垫GCL、危岩、滑坡地段库区边坡治理、施工期间水土保持等难题,并提出了解决问题的方法。     

Toxic effects of acetochlor, methamidophos and their combination on nifH gene in soil

Toxic effects of two agrochemicals on nifH gene in agricultural black soil were investigated using denaturing gradient gel electrophoresis （DGGE） and sequencing approaches in a microcosm experiment. Changes of soil nifH gene diversity and composition were examined following the application of acetochlor, methamidophos and their combination. Acetochlor reduced the nifH gene diversity （both in gene richness and diversity index values） and caused changes in the nifH gene composition. The effects of acetochlor on nifH gene were strengthened as the concentration of acetochlor increased. Cluster analysis of DGGE banding patterns showed that nifH gene composition which had been affected by low concentration of acetochlor （50 mg/kg） recovered firstly. Methamidophos reduced nifH gene richness that except at 4 weeks. The medium concentration of methamidophos （150 mg/kg） caused the most apparent changes in nifH gene diversity at the first week while the high concentration of methamidophos （250 mg/kg） produced prominent effects on nifH gene diversity in the following weeks. Cluster analysis showed that minimal changes of nifH gene composition were found at 1 week and maximal changes at 4 weeks. Toxic effects of acetochlor and methamidophos combination on nifH gene were also apparent. Different nifH genes （bands） responded differently to the impact of agrochemicals： four individual bands were eliminated by the application of the agrochemicals, five bands became predominant by the stimulation of the agrochemicals, and four bands showed strong resistance to the influence of the agrochemicals. Fifteen prominent bands were partially sequenced, yielding 15 different nifH sequences, which were used for phylogenetic reconstructions. All sequences were affiliated with the alpha- and beta-proteobacteria, showing higher similarity to eight different diazotrophic genera.     

Arsenic uptake by arbuscular mycorrhizal maize （Zea mays L.） grown in an arsenic-contaminated soil with added phosphorus

The effects of arbuscular mycorrhizal (AM) fungus (Glomus mosseae) and phosphorus (P) addition (100 mg/kg soil) on arsenic (As) uptake by maize plants (Zea mays L.) from an As-contaminated soil were examined in a glasshouse experiment.Non-mycorrhizal and zero-P addition controls were included.Plant biomass and concentrations and uptake of As,P,and other nutrients,AM colonization,root lengths,and hyphal length densities were determined.The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium.Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments,but shoot and root biomass of AM plants was depressed by P application.AM fungal inoculation decreased shoot As concentrations when no P was added,and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition,respectively.Shoot and root uptake of P,Mn,Cu,and Zn increased,but shoot Fe uptake decreased by 44.6%,with inoculation, when P was added.P addition reduced shoot P,Fe,Mn,Cu,and Zn uptake of AM plants,but increased root Fe and Mn uptake of the nonmycorrhizal ones.AM colonization therefore appeared to enhance plant tolerance to As in low P soil,and have some potential for the phytostabilization of As-contaminated soil,however,P application may introduce additional environmental risk by increasing soil As mobility.     

Degradation of metabolites accumulated of benzo[a]pyrene by coupling Penicillium Chrysogenum with KMnO4

Several main metabolites of benzo[a]pyrene （BaP） formed by Penicillium chrysogenum, Benzo[a]pyrene-1,6-quinone （BP 1,6- quinone）, trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene （BP 7,8-diol）, 3-hydroxybenzo[a]pyrene （3-OHBP）, were identified by high-performance liquid chromatography （HPLC）. The three metabolites were liable to be accumulated and were hardly further metabolized because of their toxicity to microorganisms. However, their further degradation was essential for the complete degradation of BaP. To enhance their degradation, two methods, degradation by coupling Penicillium chrysogenum with KMnO4 and degradation only by Penicillium chrysogenum, were compared; Meanwhile, the parameters of degradation in the superior method were optimized. The results showed that （1） the method of coupling Penicillium chrysogenum with KMnO4 was better and was the first method to be used in the degradation of BaP and its metabolites; （2） the metabolite, BP 1,6-quinone was the most liable to be accumulated in pure cultures; （3） the effect of degradation was the best when the concentration of KMnO4 in the cultures was 0.01% （w/v）, concentration of the three compounds was 5 mg/L and pH was 6.2. Based on the experimental results, a novel concept with regard to the bioremediation of BaP-contaminated environment was discussed, considering the influence on environmental toxicity of the accumulated metabolites.     

Impact of atrazine and nitrogen fertilizers on the sorption of chlorotoluron in soil and model sorbents

Sorption of chlorotoluron in ammonium sulfate, urea and atrazine multi-solutes system was investigated by batch experiments. The results showed application of nitrogen fertilizers to the soil could affect the behavior of chlorotoluron. At the same concentration of N, sorption of chlorotoluron decreased as the concentration of atrazine increased on the day 0 and 6 in soil, respectively. The sorption of chlorotoluron increased from 0 to 6 d when soils were preincubated with deionized water, ammonium sulfate and urea solution for 6 d. That indicated incubation time was one of the most important factors for the sorption of chlorotoluron in nitrogen fertilizers treatments. The individual sorption isotherms of chlorotoluron in rubbery polymer and silica were strictly linear in single solute system, but there were competition sorption between pesticides or between pesticides and nitrogen fertilizers. That indicated the sorption taken place by concurrent solid-phase dissolution mechanism and sorption on the interface of water-organic matter or water-mineral matter.     

Distribution and ecological effect of mercury in Laogang landfill, Shanghai, China

Laogang landfill near Shanghai is the largest landfill in China, and receives about 10000 t of daily garbage per day, Samples of topsoil and plants were analyzed to evaluate mercury pollution from the landfill. For topsoil samples, there were significant correlations among total mercury （HgT）, combinative mercury （Hgc） and gaseous mercury （HgG）, and content of total organic carbon （TOC）, but, no significantly relationship was found between Hg content and filling time. Hg content changes in vertical profiles with time showed that the average Hgv of profiles 1992, 1996, and 2000 was similar, but their average HgG was quite different. HgT was significantly correlated with Hgc in profile 1992 and 2000, and Hgv was significantly correlated with Hg6 in profile 1996. HgG/Hgv ratio in profile samples decreased in the order of （HgG,/HgT）1992〉（HgG/HgT）1996〉〉（HgG/HgT）2000. A simple outline of Hg release in landfill could be drawn： with increasing of filling time, degradation undergoes different biodegradation, accordingly, gaseous mercury goes through small, more, and small proportion to total mercury. Distribution of Hg in plants was inhomogeneous, following the order of leaf〉root〉stem. The highest value of leaf may be associated with higher atmospheric Hg from landfill. Ligneous plants （e.g. Phyllostachys glanca, Prunus salicina and Ligustrum lucidum） are capable of enriching more Hg than herbaceous plants.     

EDTA-enhanced phytoremediation of lead contaminated soil by Bidens maximowicziana

Phytoremediation is a potential cleanup technology for the removal of heavy metals from contaminated soils.Bidens maximowicziana is a new Pb hyperaccumulator,which not only has remarkable tolerance to Pb but also extraordinary accumulation capacity for Pb.The maximum Pb concentration was 1509.3 mg/kg in roots and 2164.7 mg/kg in overground tissues.The Pb distribution order in the B. maximowicziana was:leaf>stem>root.The effect of amendments on phytoremediation was also studied.The mobility of soil Pb and the Pb concentrations in plants were both increased by EDTA application.Compared with CK(control check),EDTA application promoted translocation of Pb to overground parts of the plant.The Pb concentrations in overground parts of plants was increased from 24.23-680.56 mg/kg to 29.07-1905.57 mg/kg.This research demonstrated that B.maximowicziana appeared to be suitable for phytoremediation of Pb contaminated soil,especially,combination with EDTA.     

Decomposition of alachlor by ozonation and its mechanism

Decomposition and corresponding mechanism of alachlor, an endocrine disruptor in water by ozonation were investigated. Results showed that alachlor could not be completely mineralized by ozone alone. Many intermediates and final products were formed during the process, including aromatic compounds, aliphatic carboxylic acids, and inorganic ions. In evoluting these products, some of them with weak polarity were qualitatively identified by GC-MS. The information of inorganic ions suggested that the dechlorination was the first and the fastest step in the ozonation of alachlor.     

Enzymatic oxidation of aqueous pentachlorophenol

The influence of the nonionic surfactant Tween 80 on pentachlorophenol （PCP） oxidation catalyzed by horseradish peroxidase was studied. The surfactant was tested at concentrations below and above its critical micelle concentration （CMC）. Enhancement of PCP removal was observed at sub-CMCs. The presence of Tween 80 in the reaction mixture reduced enzyme inactivation which occurred through a combination of free radical attack and sorption by precipitated products. A simple first-order model was able to simulate time profiles for enzyme inactivation in the presence or absence of Tween 80. At supra-CMCs, the surfactant caused noticeable reductions in PCP removal, presumably through micelle partitioning of PCP which precluded the hydrophobic PCP molecule from interacting with the enzyme.     

Potential of plant polyphenol oxidases in the decolorization and removal of textile and non-textile dyes

In this study an effort has been made to use plant polyphenol oxidases; potato （Solanum tuberosum） and brinjal （Solanum melongena）, for the treatment of various important dyes used in textile and other industries. The ammonium sulphate fractionated enzyme preparations were used to treat a number of dyes under various experimental conditions. Majority of the treated dyes were maximally decolorized at pH 3.0. Some of the dyes were quickly decolorized whereas others were marginally decolorized. The initial first hour was sufficient for the maximum decolorization of dyes. The rate of decolorization was quite slow on long treatment of dyes. Enhancement in the dye decolorization was noticed on increasing the concentration of enzymes. The complex mixtures of dyes were treated with both preparations of polyphenol oxidases in the buffers of varying pH values. Potato polyphenol oxidase was significantly more effective in decolorizing the dyes to higher extent as compared to the enzyme obtained from brinjal polyphenol oxidase. Decolorization of dyes and their mixtures, followed by the formation of an insoluble precipitate, which could be easily removed simply by centrifugation.     

Removal of heavy metals from sewage sludge by low costing chemical method and recycling in agriculture

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