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61.
根据油库油气回收系统的工艺要求,分析了现有油库上装发油系统实现油气密闭收集的技术难点及需要解决的问题。借鉴下装式发油的技术特点,研发了上装密闭发油系统,提出了鹤管系统及油罐车改造方案。在对现有油库上装发油鹤管不进行大规模改造的前提下,实现了上装密闭发油,经现场应用,效果良好。  相似文献   
62.
采用污染指数法和生态风险指数法对珠江口狮子洋海域表层沉积物中Hg、Cu、Cd、Pb、As等污染要素进行分析和评价。结果表明:该海域的总体污染程度为低污染水平,污染程度由大到小依次为As>Cu>Pb>Hg>Cd;该海域的总体生态风险性为低,生态风险性由高到低依次为Hg>As>Cd>Cu>Pb,Hg为该海域的主要潜在生态风险因子。  相似文献   
63.
Environmental Science and Pollution Research - The correlation coefficient can calculate paired correlations among different ecological indicators as a whole, but it cannot calculate the specific...  相似文献   
64.
A revised concept for urban water metabolism (UWM) is presented in this study to address the inadequacies in current research on UWM and the problems associated with the traditional urban water metabolic process. Feedback loops can be analyzed to increase the water environmental carrying capacity (WECC) of the new urban water metabolism system (UWMS) over that of a traditional UWMS. An analysis of the feedback loops of an UWMS was used to construct a system dynamics (SD) model for the system under a WECC restriction. Water metabolic processes were simulated for different scenarios using the Tongzhou District in Beijing as an example. The results for the newly developed UWM case showed that a water environment of Tongzhou District could support a population of 1.1926 × 106, an irrigation area of 375.521 km2, a livestock of 0.7732 × 106, and an industrial value added of ¥193.14 × 109 (i.e. about US$28.285× 109) in 2020. A sensitivity analysis showed that the WECC could be improved to some extent by constructing new sewage treatment facilities or by expanding the current sewage treatment facilities, using reclaimed water and improving the water circulation system.  相似文献   
65.
The homogeneous risk characteristics within a sub-area and the heterogeneous from one sub-area to another are unclear using existing environmental risk zoning methods. This study presents a new zoning method by determining and categorizing the risk characteristics using the k-means clustering data mining technology. The study constructs indices and develops index quantification models for environmental risk zoning by analyzing the mechanism of environmental risk occurrence. We calculate the source risk index, air risk field index, water risk field index, and target vulnerability of the study area with Nanjing Chemical Industrial Park using a 100 m - 100 m mesh grid as the basic zoning unit, and then use k-means clustering to analyze the environmental risk in the area. We obtain the optimal clustering number with the largest average silhouette coefficient by calculating the average silhouette coefficients of clustering at different k-values. The clustering result with the optimal clustering number is then used for the environmental risk zoning, and the zoning result is mapped using the geographic information system. The study area is divided into five sub-areas. The common environmental risk characteristics within the same sub-area, as well as the differences between sub- areas, are presented. The zoning is helpful in risk management and is convenient for decision makers to distribute limited resources to different sub-areas in the design of risk reducing intervention.  相似文献   
66.
介绍了武钢7#高炉供料系统槽上除尘设计的考虑因素,针对各种方法的优缺点,采用了槽上侧边抽风加移动式除尘通风口的除尘工艺,取得了很好的除尘效果。并给出了上料过程中产生的粉尘特性及所采用的除尘设备的主要参数,可供参考。  相似文献   
67.
科学大数据得以充分利用和增值的前提是开放共享,而影响数据开放共享的关键问题是共享机制.本文首先分析了科学大数据的产生方式、数据类型、投资方式、管理主体和服务定位及其与共享程度的关系.进一步在分析国内外自上而下和自下而上科学数据共享通用机制与原则的基础上,结合国家地球系统科学数据共享平台、全球变化科学数据出版等实践,提出了数据汇交、数据出版、数据联盟和服务激励四种数据共享机制,并分析了每种机制中的关键问题及具体做法.最后,结合云计算、"互联网+"等新一代信息技术和思维,对环境保护大数据共享机制提出四点建议,即:国家统一投资建设的环境保护核心业务数据强制汇交机制,其他部委、机构环境保护相关数据联盟交换机制,企业、科学家个人数据出版等激励机制,以及社会公众数据的"众创机制".  相似文献   
68.
利用防火板材防护钢构件是钢结构防火的重要措施之一,而防火板材的隔热性能决定了钢结构的耐火性能, 为了研究建筑领域常用防火板材隔热性能,以及防火板材受火破坏形态和隔热性能随温度变化的规律,设计制作了 14 个防火板隔热性能试件,在三种火灾工况下对建筑领域常用防火板材进行隔热性能试验。研究结果表明:(1) 板材受火后的破坏形态和裂纹开展情况都与火灾升温历史有关;(2)板材受热过程中分解的结合水蒸发吸热是缓解钢板升温的重要影响因素之一;(3)用 ISO 834 标准升温下板材温度平台区域的 λ 取值结果来指导其他两种火灾情形下防火构造设计是安全的;(4)利用板材表面空气温度和钢板温度测试结果获得了板材导热系数,数值模拟计算与试验结果吻合良好,验证了采用导热系数测量方法的可靠性;(5)利用数值模拟与试验相结合的方法,分析得到石膏板的温度?等效导热系数简化曲线的两个重要敏感参数:热质传递影响温度区间等效导热系数结束变化的温度点(470 ℃)和该温度区间的等效导热系数波谷极值大小。  相似文献   
69.
对某机场制氧制氮站发生的一起充氮拖车上的高压氮气瓶燃爆事故进行分析,找出了事故的原因,提出了几点建议。  相似文献   
70.
• 1,4-Dioxane was degraded via the photo-Fenton reactive membrane filtration. • Degradation efficiency and AQY were both enhanced in photocatalytic membrane. • There is a tradeoff between photocatalytic degradation and membrane permeation flux. • Degradation pathways of 1,4-Dioxane is revealed by DFT analysis. The present study evaluated a photo-Fenton reactive membrane that achieved enhanced 1,4-Dioxane removal performance. As a common organic solvent and stabilizer, 1,4-Dioxane is widely used in a variety of industrial products and poses negative environmental and health impacts. The membrane was prepared by covalently coating photocatalyst of goethite (α-FeOOH) on a ceramic porous membrane as we reported previously. The effects of UV irradiation, H2O2 and catalyst on the removal efficiency of 1,4-Dioxane in batch reactors were first evaluated for optimized reaction conditions, followed by a systematical investigation of 1,4-Dioxane removal in the photo-Fenton membrane filtration mode. Under optimized conditions, the 1,4-Dioxane removal rate reached up to 16% with combination of 2 mmol/L H2O2 and UV365 irradiation (2000 µW/cm2) when the feed water was filtered by the photo-Fenton reactive membrane at a hydraulic retention time of 6 min. The removal efficiency and apparent quantum yield (AQY) were both enhanced in the filtration compared to the batch mode of the same photo-Fenton reaction. Moreover, the proposed degradation pathways were analyzed by density functional theory (DFT) calculations, which provided a new insight into the degradation mechanisms of 1,4-Dioxane in photo-Fenton reactions on the functionalized ceramic membrane.  相似文献   
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