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.     

从大数据角度看中国共产党绿色执政理念的变迁

2021年是中国共产党成立100周年，是“两个一百年”奋斗目标的交汇之年。中国共产党成立以来，党的绿色执政方略从“打土豪、分田地”到“全国土地会议”，从“节约粮食和土地资源”到“环境保护成为基本国策”，从“可持续发展”到“习近平生态文明思想”，回顾历史，绿色执政理念日益深入人心。本研究以《建党以来重要文献选编（1921—1949）》《毛泽东选集》《邓小平文选》《习近平谈治国理政》和国务院政府工作报告等为资料来源，基于机器学习自然语言处理大数据分析方法，使用隐含狄利克雷分布模型和KH Coder可视化软件，对重要文献选编和政府工作报告中中国共产党绿色执政理念有关文字表述内容进行统计和分析，系统梳理绿色执政理念的发展脉络。研究发现，习近平生态文明思想是中国共产党绿色执政理念的集大成者，是新时代新发展阶段加强生态环境保护的指导思想和行动指南，对走好“两个一百年”目标交汇点上绿色发展的第一步具有重要指导意义。     

控制森林大火系统工程

本文论述林火管理中防止大火成灾的重要性,并以系统工程为主要手段,通过计算机运算提供的数据,指挥人员选用相对优化的决策。依靠现代化的灭火技术,最大限度地制止大火蔓延直到熄灭,其目标是把火灾损失限制在最小程度.     

Environmental performance rating and disclosure: China's Green Watch program

In this paper we describe a new incentive-based pollution control program in China, in which the environmental performance of firms is rated from best to worst using five colors--green, blue, yellow, red and black--and the ratings are disseminated to the public through the media. We focus on the first two municipal disclosure programs, which have been implemented at very different levels of economic and institutional development. In both cases, the increases in compliance with pollution regulations have been similar to increases produced by public disclosure programs in Indonesia, the Philippines, and Vietnam. The results suggest that incentives created by public disclosure may significantly reduce pollution in China, even though environmental NGO's play little role and there is no formal channel for public participation in environmental regulation.     

臭氧消毒现状与发展

阐述了臭氧消毒灭菌的基本原理、臭氧制备、消毒工艺流程以及国内外应用概况，探讨了给水采用臭氧消毒存在的主要问题及改进方向。指出臭氧消毒法有可能取代传统的氯化消毒法，尤其在给水工艺中具有广阔的应用前景。     

钻井污水与采油污水混合处理

中原油田产生的钻井污水的化学需氧量(COD)、矿化度、色度、悬浮物及含油量均比较高,直接外排将会对周边生态环境造成污染,与采油污水混合处理又将导致处理后的水质达不到标准,因而采用将钻井污水处理后再与采油污水混合的方法,这种混合污水进入采油污水处理系统的试验结果表明,处理后的钻井污水与采油污水配伍性良好,净化水无结垢倾向,处理后的净化水与杀菌剂、缓蚀剂相容性良好,其主要指标均达到部颁注水水质标准。     

长江流域粮食生产态势与潜力

通过大量的资料分析了长江流域在进入９０年代后的粮食生产的消费态势。粮食生产过程中存在的主要问题,及其对讹诈 影响,资料分析表明,长流域七省一市的粮食生产表现为,粮食单产略有提高,粮食总产徘徊,粮食消费量与居民的经济收入密切相关。     

长江三角洲耕地资源态势与保护对策

长江三角洲是我国东部沿海经济最发达的地区,在全国占有十分重要的经济地位。随着经济的发展,资源与环境发生了严重的问题,特别是近年来耕地资源锐减,而后备耕地资源却短缺,人地人粮矛盾更加尖锐,已成为影响这一地区农业持续发展的重要因素。本文分析了这一地区的经济特点与耕地资源的变化态势,并提出了相应的耕地保护措施。首先,要严格控制非农用地,确保基本农田,其次要采用经济手段,建立保护耕地的经济机制;此外,还要     

应用事故致因理论，研究事故预防对策──关于防止铁路机车车辆伤害事故的探讨

应用事故致因理论，探讨机车车辆伤害事故的本质，研究机车车辆伤害事故的发生规律及成因模型，提出预防机车车辆伤害事故的对策。     

湖泊中水下植物光合作用对溶解氧和pH值的影响

文章研究了湖泊中水下植物光合作用对湖水ＤＯ和ｐＨ的影响，提出了预测ＤＯ和ｐＨ变化的计算方法