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591.
为解决村镇应急避难场所面临暴雨灾害时的风险问题,基于故障树和置信规则库推理方法,提出暴雨灾害链和村镇应急避难场所功能破坏链相结合的场所避难功能失效风险诊断模型。根据事故致因理论推理灾害节点变量,通过故障树描述灾害链,运用关联规则从历史灾害数据中挖掘规则,建立置信规则库系统,构建村镇应急避难场所功能失效风险诊断模型,并以四川省某寄宿制学校为例进行模型验证。研究结果表明:该模型可实现不同证据组合下村镇应急避难场所功能失效风险的诊断推理;实例的模型诊断结果与实际情况吻合,证实该模型能够科学地诊断村镇应急避难场所面临暴雨等恶劣自然条件时存在的风险,可为村镇应急避难场所规划设计和应急管理提供理论支撑。 相似文献
592.
染整废水深度处理纳滤工艺膜污染成因分析 总被引:2,自引:1,他引:1
为调查棉针织染整废水纳滤脱盐系统膜污染的类型和成因,使用电感耦合等离子发射光谱仪、扫描电子显微镜-EDX能谱仪、傅里叶变换红外光谱仪、热重分析仪、高倍光学显微镜和X射线荧光光谱仪,从膜进水水质、膜过程污染状况和膜清洗效果等三方面进行了联合互补检测和综合分析.结果表明,棉针织染整废水脱盐过程中纳滤膜的污染类型包括无机污染、有机污染和微生物污染;干燥(105℃)的污染物成分组成中结合水所占质量分数约8.2%,有机成分所占质量分数约41.0%,无机成分所占质量分数约50.8%;在无机污染物中铁盐污染较为突出,有机污染物所包含的主要官能团为—OH、—CH和—CC,微生物污染物中包含原生动物和后生动物;短期膜污染和长期膜污染分析结果表明有机污染和微生物污染的形成需要长时间的累积效应;纳滤膜清洗试验结果表明,有机污染和微生物污染是引起膜通量下降的主要原因,两者对膜通量影响的贡献率约53.3%. 相似文献
593.
重点介绍了冶金企业包括瓦斯泥、瓦斯灰、转炉泥、选矿废渣、高炉矿渣、转炉钢渣在内的固体废弃物的基本特征以及对环境的污染情况。并对其有效元素回收和资源化利用提出建议。 相似文献
594.
Dongkai Xu Rajiv Malhotra N. Venkata Reddy Jun Chen Jian Cao 《Journal of Manufacturing Processes》2012,14(4):487-494
Single point incremental forming (SPIF) is a new sheet metal forming process characterized by higher formability, product independent tooling and greater process flexibility. The inability of conventional single pass SPIF to form vertical walls without failure is overcome by forming multiple intermediate shapes before forming the final component, i.e., multi-pass single point incremental forming (MSPIF). A major issue with MSPIF is significant geometric inaccuracy of the formed component, due to the generation of stepped features on the base. This work proposes analytical formulations that are shown to accurately and quantitatively predict the stepped feature formation in MSPIF. Additionally, a relationship is derived among the material constants used in these analytical equations, the yield stress and thickness of the blank material, such that the computational effort required for the calibration of these constants can be minimized. Finally, the physical effects of yield stress and sheet thickness on the rigid body translation are further discussed. 相似文献
595.
596.
China has experienced considerable urbanization in the past 60 years,especially since the implementation of the Economic Reform and Opening-up Policy in 1978.In 1949,there were only 132 cities with an urban population of 27.4 million,while in 2008 China had 652 cities with a total urban population of 606 million.Such urbanization is attributed to the boost in the number of cities and the urban population.Urban expansion enhanced geographic inequality between the three major regions in China.Compared with the eastern and central regions,western China only has 19%of the total cities and 18%of the urban population.The urbanization rate was 37.2%for the western region in 2008,while it reached 53.3%for the eastern regions and 45.3%for central China.Using a geographic information system(GIS)and statistical analyses,this study aims at explaining the structure and spatial development of urbanization,and highlighting the current issues of urban inequality in western China during the past two decades.The paper drew following conclusions:(1)Urbanization disparities between eastern and western China have become increasingly obvious,but seem to be evolving slowly since the establishment of the government’s Western Development Priority Policy in 2000.(2)Cities of various sizes were expanded in western China,and the main factors affecting the urbanization are population numbers and density,government investment and geographic conditions.(3)Current patterns of urbanization in the western region are distributed unevenly between provinces. 相似文献
597.
Abstract The natural supply of land resources is limited, but the economic supply may change along with social and economic development, and its size is decided bye nature and social and economic body conditions. When the supplying ability of land resources threatens the development of society and the conflict between people and land becomes tense, it forced people to improve land utilization and to increase the effective supply of land resources. The paper made an overall consideration on the characteristics of the irrigated farming and the frail ecological environment in Fuhai County, Altay Area, Xinjiang Uigur Autonomous Region and explored land arrangement planning as well as water resource planning and environmental protection. The paper evaluated natural resources, land utilization and water resource of the case study areas and focused on the spatio-temporal balance between the utilization of water and land resources. In the end the paper a feasible plan was made out for the land arrangement project. 相似文献
598.
Abstract It is difficult to realize the transformation from traditional economy industrial system to circular economy industrial system. Regarding primary raw materials as the indicators, the industrial system has been specified according to the divergence among the indicators and the circular utilization modes. In comparison with the association among industrial systems, the relationship among industrial sub-systems is named as industrial cross-linking in this paper. The industrial system which could completely utilize and recycle the indicators should be increased and strengthened, and the circular economy industrial system with complete industrial association and industrial cross-linking should also be constructed. Taking the development of circular agricultural system basing on the traditional agricultural system as an example, the traditional agricultural products are regarded as the indicators which have been divided into foodstuff and crop straws which are used to produce food and articles for use, like fertilizer, energy and papers etc. The way to construct the circular agricultural industrial system is to increase the industrial systems that could utilize the products generated from crop straws, feces and other castoffs and transform the wastewater and other trucks into environmental friendly products. It has also been pointed out that the construction of circular economy industrial system is conducive to the foundation of circular industrial economics and the establishment of the construction layout of circular economy and the application schemes. Suggestions to the theoretical and practical work of the next step have also been brought forward in this paper. 相似文献
599.
Abstract Suburbanization in large cities is an important phenomenon in the process of urbanization development in China in recent decades, which plays a very important role in promoting city development, whereas some side effects on the eco-environment appeared at the same time. This paper, taking Xi’an City in China as a case study site, analyzed the features of population suburbanization and industry suburbanization and pointed out the impacts of suburbanization on urban eco-environment. Based on the research, suggestions of countermeasures for urban planning and municipal management of Xi’an City in protecting urban eco-environment and conserving natural ecology were put forward in the end. 相似文献
600.
Cheng Yuan Cao Xu-bing Liu Jiu-meng Zhu Shengqiang Wang Siyu Yu Qin-qin Zhang Hongliang Zhang Qiang He Ke-bin 《Environmental Chemistry Letters》2022,20(5):2745-2750
Environmental Chemistry Letters - Heterogeneous reactions involving aerosol water, i.e., haze chemistry, are responsible for high aerosol concentrations observed during severe haze events in... 相似文献