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排序方式: 共有98条查询结果,搜索用时 31 毫秒
81.
国家决定“十五”期间每年投入9亿,重庆配套3亿用于三峡库区城镇污水处理场建设和生态建设,这一大批污水处理场谁来组织,如何组织,采用什么运行机制,怎样实现污水处理设备产业化,建成之后如何确保稳定运行,无疑都是战略性问题,本文对这些问题作了大胆的探索,认为应进行市场化系统推进。  相似文献   
82.
数字化地震前兆台站的防雷措施   总被引:1,自引:1,他引:1  
雷电灾害是气象自然灾害的一个组成部分.地震前兆台站的防雷问题是一个十分重要的问题,然而防雷技术目前在国际上尚未过关.随着数字化改造项目的实施,地震台站对防雷技术的要求越来越高.本文分析了雷电的形成、雷击的种类和雷电对数字化前兆地震台站的危害,介绍了几种针对数字化前兆台站的防雷措施,这些措施在实际的地震监测中取得了较好的效果,值得借鉴推广.  相似文献   
83.
本文依据国家防雷标准,以及温泉台地形、地质的实际情况对温泉台在十五改造中需要引起足够重视的防雷措施进行了具体的设计和施工。经本地区有关防雷部门的测定,各项指标均达到了国家防雷标准。希望能够为台站在防雷建设方面提供一个例证。  相似文献   
84.
电视机和有线通讯设备的生产,均采用流水线作业方式,390名生产工人的主要慢性肌肉骨骼损伤有手疲劳、右臂疲劳及肩痛,与对照人群比较,P〈0.05差异显著。手痛、腕痛、颈痛及上下背痛虽多于对照人群,但无统计学意义,这与Laopajarri和shihan 等报告不同,这可能与当时工厂定额相对较低,全天纯劳动工时相对短有关  相似文献   
85.
Electromagnetic field sources used for communication always have been subject of serious interest. There are many publications concerning exposure and risk assessment of the working in such environment. Results of epidemiological study performed in Bulgaria in the 1990's show exceeding of the maximal permissible values especially in radio stations for the personnel in 24 h working shift [Israel et al. (1992). Study of the electromagnetic in its influence on personnel working in radio and TV stations, Report, National Centre of Hygiene, Medical Ecology and Nutrition; Israel and Tomov (2001). Epidemiological study of the effects of radiofrequency radiation on operators in radio, TV and relay stations, Proceeding of the Eastern European Regional Meeting and Workshop “Measurements and Criteria for Standard Harmonization in the field of EMF Exposure” and WHO EMF Standards Harmonization Meeting, Varna, Bulgaria, 28 April—3 May, 2001, pp.145–153]. In the last years the situation is strongly influenced by the development of the technology which leads to changes in equipment in radio and TV stations, using lower power, facilitate the working regime. The paper presents data of exposure assessment of different professional groups in selected radio and TV stations. Assessment is being performed on basis of EMF parameters values and energetic load calculations according to the national legislation. Data are compared with the results of previous investigation to evaluate the new situation in this branch. Exposure levels are much lower than those in the previous study, and lower compared to the exposure limits, as well [Israel et al. (1992). Study of the electromagnetic in its influence on personnel working in radio and TV stations, Report, National Centre of Hygiene, Medical Ecology and Nutrition; Israel and Tomov (2001). Epidemiological study of the effects of radiofrequency radiation on operators in radio, TV and relay stations, Proceeding of the Eastern European Regional Meeting and␣Workshop “Measurements and Criteria for Standard Harmonization in the field of EMF Exposure” and WHO EMF Standards Harmonization Meeting, Varna, Bulgaria, 28 April—3 May, 2001, pp.145–153].  相似文献   
86.
针对居住在城市移动基站附近的居民日益关注的电磁辐射污染问题,通过移动基站近距离区域电磁场分布连续24h监测与分析,研究正常工作日内基站周围近距离区域电磁场功率密度随时间和距离的变化,以及功率密度的概率分布,并根据24h各时段内的话务量,使用统计分析(SAS)系统对此影响因素进行相关性分析.结果显示,一天内移动基站天线附近电磁辐射随时间呈现明显的波动,其功率密度的概率分布接近正态分布,手机的话务量与电磁场强度具有一定的相关性.在近距离区域,功率密度随距离增加,在一定距离上出现峰值,峰值出现的距离与天线高度有关.对我国一般的城市基站,环境电磁辐射低于标准限值.  相似文献   
87.
作为高能耗行业,通信行业中通信基站的散热能耗量就一直居高不下,如何降低其能耗是目前各运营商迫切期待解决的问题。针对这一问题,根据烟囱效应增强对流散热的原理,提出了一种"烟囱"通风与空调降温相结合的通风冷却系统设计方案,然后通过三维热-流体耦合计算分析了影响此结构散热的关键因素,在此基础上采用正交实验对基站散热结构的参数进行了优化,最大化降低基站运行的温度,从而达到了减少通信基站运行成本的目标。  相似文献   
88.
Vultures, the only vertebrate obligate scavengers, are currently facing a dramatic worldwide decline with over half of vulture species now classified as threatened. To address this widespread decline, the use of feeding stations has been widely advocated in recovery programs. However, providing food that is more predictable in time and space than natural resources could disrupt the ecological scavenging service provided by vultures. In this study, we build a multi-agent system (MAS), which describes the social foraging behavior of Gyps vultures in order to investigate how resource predictability in space and resource management affect scavenging service efficiency. We study the possibility that vultures take into account feeding station location in addition of using local enhancement. Our results show that the efficiency of the scavenging service is heavily affected by the way resources are distributed between feeding stations and natural areas. Nevertheless, it appears possible to minimize a loss in service efficiency by increasing the number of feeding stations while keeping the total amount of resources available constant, thus reducing the predictability of the resources located on the stations. We illustrate our work in the case of European feeding stations that provide supplementary resources in areas where natural ones are scarce. Moreover, we discuss the implications worldwide, in particular in the case of India, where feeding stations for vultures are intended to lure individuals away from potentially harmful natural carrion.  相似文献   
89.
油气回收技术在加油站中的应用   总被引:9,自引:0,他引:9  
介绍了加油站油气回收的意义、油气回收系统的工艺原理及油气回收系统性能的检测方法.对油气回收系统设备的安装进行了说明,并对油气回收的综合利用提出了建议。  相似文献   
90.
ABSTRACT: Fuels contained in underground storage tanks (USTs) are a major source of soil and ground water contamination. Effective management of the problem at the urban level is difficult due to a large number of tanks and a vast array of factors (e.g., tank characteristics, geology) that determine environmental hazards. The problem is compounded by frequent abandonment and reuse of service stations, which makes it difficult to track the status of underground tanks. Geographic information systems (GIS) are ideally suited to organizing location and attribute data for variables that are pertinent to the UST management problem. A GIS-based UST management system was developed and applied to 136 current and former gasoline service stations in Denton, Texas. The system is effective for tank inventory and can be applied in a proactive fashion to identify potentially problematic facilities. In the event of a leak or spill, the management system can support the implementation of reactive measures to mitigate subsurface contamination. Potential beneficiaries of such a system include planning departments, environmental regulatory agencies, emergency management officials, lending institutions, gasoline distributors, and oil companies.  相似文献   
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