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371.
简要介绍国外(美国)遥感测量技术在汽车排气检测领域的应用,并通过对广州市道路实车试验采集的数据进行机动车排放调查和IAVI项目评估,结果表明这些排放调查和评估工作是可行的,结果是可靠的。 相似文献
372.
This article discusses developments in the area of product service systems (PSS) and the need to facilitate the proliferation of the PSS approach through public policies. The article argues that policies that establish the framework conditions for environmental improvement are preferable to detailed legislation as they favour environmentally superior PSS. However, there is also a need for more specifically targeted policy measures that stimulate knowledge creation and dissemination in the PSS area. This article suggests that informative policy measures should be used by authorities and reviews the results from the functional programme of the Swedish EPA as an example of this type of policy. 相似文献
373.
王建平 《城市环境与城市生态》2006,(4)
随着房地产楼盘品质的提高,景观质量日益受到重视。分析住宅小区不同位置住宅单元的景观特点,对于掌握住宅单元的品质,确定合适定价策略有着重要意义。根据景观生态学理论,设计了表示住宅单元景观特点的指数。应用景观生态学的景观格局分析方法与虚拟现实技术的可视域分析方法,提出了对住宅单元可视景观特点进行定量分析方案。对典型住宅小区多个住宅单元的可视景观特点进行了模拟计算,计算结果较好地反映了实际的景观特点,从而为住宅单元景观质量定量评估提供了技术可能性。 相似文献
374.
介绍利用计算机对铁路客车空调换热器进行设计计算,建立空调换热器的数学模型,绘制流程图,根据实际经验指出了编制程序过程中应注意的问题.以CA25B型空调餐车为例,利用所编程序,对其蒸发器按不同的管排列方式分别进行了设计,指出差排比顺排更适用于空调列车.最后得出结论:电算能大大缩短设计时间,提高计算准确度,并能快速对多种方案进行比较而选取换热器的最佳结构形成,达到节能和节约材料的目的. 相似文献
375.
John F. Walker Susan A. Pickard William C. Sonzogni 《Journal of the American Water Resources Association》1989,25(1):139-147
ABSTRACT: Although several sophisticated nonpoint pollution models exist, few are available that are easy to use, cover a variety of conditions, and integrate a wide range of information to allow managers and planners to assess different control strategies. Here, a straightforward pollutant input accounting approach is presented in the form of an existing model (WATERSHED) that has been adapted to run on modern electronic spreadsheets. As an application, WATERSHED is used to assess options to improve the quality of highly eutrophic Delavan Lake in Wisconsin. WATERSHED is flexible in that several techniques, such as the Universal Soil Loss Equation or unit-area loadings, can be used to estimate nonpoint-source inputs. Once the model parameters are determined (and calibrated, if possible), the spreadsheet features can be used to conduct a sensitivity analysis of management options. In the case of Delavan Lake, it was concluded that, although some nonpoint controls were cost-effective, the overall reduction in phosphorus would be insufficient to measurably improve water quality. 相似文献
376.
Janusz R. Rydzewski Saeed Nairizi 《Journal of the American Water Resources Association》1979,15(2):316-325
ABSTRACT: The deliberate underwatering of a larger land area, as practiced in Southern Asia, has provided impetus for a systematic investigation into the effects of designing projects for crop water deficits on Benefit-Cost performance. The study began with the derivation, from published experimental results, of functions relating ultimate crop yield to the magnitude and timing of water deficits, i.e., of the productivity of irrigation water. To obtain the net benefit of the project, the relation between the harvested area and output and the on-farm production costs was then suggested. The cost of supplying the irrigation water to the proposed area and of distributing and applying it to the field was determined, thus completing the Benefit-Cost equation. A computer simulation model was then established to search for the irrigation project design capacity and area to maximize the net present value in the Benefit-Cost analysis for the development proposed. 相似文献
377.
Darryl W. Davis 《Journal of the American Water Resources Association》1978,14(3):587-604
ABSTRACT: A pilot study undertaken to develop and test analytical methodologies for application in comprehensive flood plain information studies is described. The methodology permits and encourages comprehensive, systematic, practical assessments of present and alternative future basin-wide development patterns as reflected by alternative land use patterns and physical works in terms of flood hazard, economic damage potential and selected environmental consequences. The analysis methodologies are centered about integrated use of computerized spatial, gridded geographic and resource data files. A family of special purpose utility computer programs access the data file and extract appropriate variables and interpret and format the data into specific analytical parameters that are subsequently formatted for input to traditional modeling computer programs. An example application to Trail Creek in Clarke County, Georgia, is described. 相似文献
378.
ABSTRACT: The National Regulatory Research Institute has recommended the merger of small rural water districts in the United States. Success at bringing about merger of these districts, which contain fewer than 3,500 customers, has been highly limited. The subject of this paper is a demonstration project that may act as a catalyst to achieve the desired goal of regionalization. A computerized hydraulic data management program (CHDMP) was developed for a case study in Nelson County, Kentucky. University professors, graduate students, and two water utilities’ staffs cooperated in network analysis employing computer hardware and software. The utilities’ staffs were taught the science and technology of hydraulic model preparation, simulation, and analysis for the case study distribution systems. As an integrated system, the model contained 294 pipes, 234 nodes, six pumps, and 11 tanks. Each utility's problem areas were identified and some of the individual and mutual benefits of hydraulic planning were illustrated. A dialogue resulted between the managers. Each manager described his goals and agreed that, although political merger was not feasible at the present time, future economic factors could be a definite influence in reversing that decision. 相似文献
379.
Walter M. Grayman Richard M. Males Robert M. Clark 《Journal of the American Water Resources Association》1988,24(6):1311-1316
ABSTRACT: Information on raw water quality, treatment process removal efficiency, and distribution system monitoring is essential to the proper management and operation of a water utility system. Microcomputer hardware and software systems using commercially available data base management systems (DBMS) have emerged within the last few years as an effective means of managing, analyzing, and displaying water quality data. Understanding hardware, software, and training requirements is essential to the proper use of these systems. Three types of data base design are common: relational, hierarchical, and network. Only the relational type of data base architecture is widely implemented on microcomputer DBMS. In this paper two examples of the application of DBMS to water utility problems are presented. One example deals with collection and analysis of data concerning the water quality of the Mississippi River. The second example deals with the DBMS as a means of analyzing water quality data in the North Penn Water Authority (NPWA) distribution system. 相似文献
380.
废旧电脑的处置现状与绿色电脑概念的普及 总被引:4,自引:0,他引:4
慨述了发达国家在废电脑处理方面的现状,并对绿色电脑进行了分析与展望。 相似文献