Copula-Based Bivariate Return Period Analysis and Its Implication to Hydrological Design Event

In univariate frequency analysis, the return period of an event has a one-to-one correspondence with its characteristic value, and the response of the hydraulic structure to hydrological load expressed by the hydrological event is monotonic. Thus, the design criteria of the hydraulic structure can be equivalently represented by the return period of the hydrological event, and consequently, design event-based design parameters evaluated have been widely used in practical engineering. However, the monotonic correspondence between the return period of the hydrological event and the response of the hydraulic structure does not exist in the multivariate context, and hydrological load with a larger joint return period does not always produce a more unsafe response. Misunderstandings of concepts of return periods of hydrological event, and estimation of hydrological design events usually take place in multivariate frequency analysis. This study theoretically derives the relations between different types of joint return periods, joint return period and its marginal return periods, the occurrence of bivariate extreme events and their return periods, and then the theoretical framework is tested. Results from the case contribute to the understanding of bivariate return periods of hydrological event, and the results demonstrate that design criteria cannot be equivalently represented by joint return periods of hydrological load, and design parameters of the hydraulic structure should not be determined by multivariate hydrological design events.     

电厂山区性河流取水工程安全设计分析

通过对代表性山区河流电厂的取水工程安全实例分析 ,根据取水方式不同 ,建议应采取的措施分为 :直接在天然河道上布置取水构筑物时 ,取水头部上下端加设三角形挡沙板 ,取水口上游设导沙丁坝 ,抬高取水头高程和进水底槛高程 ,并且可考虑设置两套取水系统 ,枯水期直接利用河道取水头取水 ,洪水期从移动式泵车取水 ;在河道上设置拦河低坝取水时 ,必须设置配套取水防沙设施 ,如排沙闸或冲沙闸 ,进水闸前设导沙坝 ,冲刷闸前设导沙坎 ,泄洪闸前设冲沙廊道和导流堤 ,还可在河道上设置潜水丁坝等。     

光催化法降解有机废水的显著性研究

本文采用紫外光照射并加入催化剂的方法，对有机废水一阳离子艳红染料(5GN)进行了光催化降解的研究。从实际应用出发，实验得出了影响阳离子艳红染料降解的各因素的最佳取值及影响显著性次序。     

Effect of soil properties on saturated and unsaturated virus transport through columns

Viruses from contaminant sources can be transported through porous media to drinking water wells. The objective of this study was to investigate inactivation and sorption of viruses during saturated and unsaturated transport in different soils. Bacteriophages phiX174 and MS-2, and Br- tracer in a phosphate-buffered saline solution were introduced into saturated and unsaturated soil columns as a step function under constant flow rate and hydraulic conditions. Results showed that significantly greater virus removal occurred in the unsaturated columns than in the saturated columns in the two soils containing high metal oxides content. However, the increase in virus retention under unsaturated conditions was not significant in two other soils having high phosphorus and calcium contents and high pH, and in another soil with high organic matter content. The results imply that the extent of water content effect on inactivation and sorption of viruses can range from significant to minimal depending on the properties of the transport medium. We found that the presence of in situ metal oxides was a significant factor responsible for virus sorption and inactivation. Therefore, soils with high metal oxides content may have the potential to be used as hydrological barriers in preventing microbial contamination in the subsurface environments. We also found that the water content effect on virus removal and inactivation strongly depended on solid properties of the testing medium.     

广东省香蕉寒害风险分析

根据各地寒害及香蕉的产量资料,从寒害对香蕉产量的影响出发,对广东省各地香蕉的灾损率、易灾性进行了分析,以寒害风险指数作为区划指标,对广东省的香蕉寒害风险进行了区划,并作了分区评述。     

中国城市综合减灾体系建设及其系统思考

从中国城市减灾现状分析入手,重点剖析城市减灾的可持续发展问题,并探讨了城市社会经济可持续发展中如何确立防灾减灾的地位．进而用系统科学思路研究城市综合减灾的体系建设问题,从一定意义上较为科学地解决了跨世纪的中国城市可持续发展的关键问题．     

煤矿粉尘沉积模型的研究

推导了落尘的沉积模型,提出了落尘聚集体、落尘凝结体的概念。通过对落尘颗粒间四种主要内聚力以及气流浮力的量级分析,指出矿井条件下抑制落尘颗粒二次飞扬的前提是使尘粒得到充分的湿润,并进行了两种集合体的二次飞扬试验     

峨眉山环境现状研究

峨眉山是世界名山，其主要风景林－－冷杉出现大面积衰败和死亡。本文概述了峨眉山的地理和气候特点，研究了土壤、植被、大气环境及旅游现状；为深入研究峨眉山冷杉衰亡的原因提供基础资料，为恢复和建设峨眉山的生态环境提供思路和参考。     

高价值综合利用攀钢钛矿渣的途径─－利用提钛后残渣生产复合水泥与少熟料水泥

本文较系统地研究了提钛后的残渣、矿渣、熟料、激化剂等因素对复合水泥与少熟料水泥强度的影响；找出了利用提钛后的残渣生产复合水泥与少熟料水泥生产的最佳条件，并对复合水泥和少熟料水泥的性能进行了初步探索。试验数据表明，利用提钛后残渣可生产５２５￣＃复合水泥和４２５￣＃少熟料水泥，工业废渣利用率可达７０％。     

废钻井液对环境污染及固化处理室内研究

目前我国许多油田钻井井场位于稻田、麦田、虾池和鱼塘周围，而废钻井液中含有无机盐、重金属组分、油品及大量有机聚合物，其中有些是有害物质，一口井的废钻井液一般可达200～300m~3。这些废钻井液堆放在井场不进行处理会对周围环境造成较大污染。为此，如何处理这些废钻井液是目前令人极为关心的课题。本文分析了我国一些油田废钻井液的毒性；介绍了毒性提取、评价方法及其对土壤、植物和海洋生物的影响，同时重点介绍用化学固化方法处理废钻井液的结果。通过对现场的5个废钻井液的固化处理室内试验证实，废钻井液固化后有一定强度，其水浸出液清彻透明，达到排放标准，固化体可进行掩埋恢复地貌，也可作为建筑材料使用。