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921.
Jeffrey C. Sutherland Robert M. Bruce 《Journal of the American Water Resources Association》1977,13(6):1215-1226
ABSTRACT: The East Lansing-Meridian Water and Sewer Authority studied a sand-gravel esker near the existing water treatment plant to determine its potential as an independent surface water supply. The nearby Red Cedar River was also investigated as a possible source of water for immediate treatment or for recharge of the esker. Although the bedrock aquifer (Grand River and Saginaw Formations) yields water adequate for the next 20 years, potential savings in treatment (hardness, iron) and pumping costs, estimated at $30,000 per year for present demand of 5 MGD, are attractive incentives for a surface water-esker recharge program. Operation savings would also be realized by constructing additional bedrock wells in new areas. The river-esker-recharge and new wellfield alternatives are compared for cost-effectiveness. Land costs make the recharge alternative more expensive. The land is undeveloped suburban property with potential for recreational use in conjunction with water supply. More places of outdoor retreat and aesthetics are needed in the Lansig Metropolitan area. A portion of the land costs would have to be borne by these or other interests for the river recharge scheme to be economically feasible. 相似文献
922.
Gary R. Minton Richard Williams Thomas Murdock 《Journal of the American Water Resources Association》1980,16(3):486-493
ABSTRACT: This paper discusses the selection and use of criteria for an institutional analysis of municipal water supply conducted in anchorage, Alaska. Although not universally acepted or used. evaluation criteria for most technical fields have been established either formally or informally. Cost-benefit rtios, cost-effectiveness, and environmental impacts are examples of technical evaluation criteria that can be quantified relatively easily (although poorly in some cases). The field of institutional analysis has evaluative criteria that are much less readily defined than those of technical fields, in part because many of the criteria are not quantifiable and in part because the area of the study is new. 相似文献
923.
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
924.
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
925.
926.
- This commentary compares the primary energy requirement for apples (cultivar Braeburn), which were either imported or locally-grown in Meckenheim, Germany. Imported apples of the same cultivar were grown in a Southern hemisphere winter in Nelson, Southland, New Zealand, and were picked at the end of March with subsequent 28 d transport by sea for sale in April in Germany. Locally-grown apples (cultivar Braeburn) were picked in mid-October and required a primary energy of nearly 6 MJ/kg of fruit including 0.8 MJoule/kg for five months CA storage at 1°C during a Northern hemisphere winter until mid-March. This compared favourably with 7.5 MJoule/kg for overseas shipment from New Zealand, i.e. a ca. 27% greater energy requirement for these imported fruits. Overall, the primary energy requirement of regional produce, stored several months on-site, partially compensated for the larger energy required to import fresh fruit from overseas. This result is in marked contrast to reported overestimates of a reported up to 8-fold energy requirement for domestic versus imported apple juice concentrate [7]. Our own findings of less primary energy required for domestic apple fruit is discussed with respect to providing local employment, fruit orchards preserving the countryside, quality assurance systems for local fruit such as QS and EUREP-GAP, networking and other factors favouring regional production. 相似文献
927.
Heavy metal pollution in China: Origin,pattern and control 总被引:21,自引:2,他引:21
Cheng S 《Environmental science and pollution research international》2003,10(3):192-198
GOAL, SCOPE AND BACKGROUND: Heavy metal is among one of the pollutants, which cause severe threats to humans and the environment in China. The aim of the present review is to make information on the source of heavy metal pollution, distribution of heavy metals in the environment, and measures of pollution control accessible internationally, which are mostly published in Chinese. METHODS: Information from scientific journals, university journals and governmental releases are compiled focusing mainly on Cd, Cu, Pb and Zn. Partly Al, As, Cr, Fe, Hg, Mn and Ni a included also in part as well. RESULTS AND DISCUSSION: In soil, the average contents of Cd, Cu, Pb and Zn are 0.097, 22.6, 26.0 and 74.2 mg/kg, respectively. In the water of the Yangtze River Basin, the concentrations of Cd, Cu, Pb and Zn are 0.080, 7.91, 15.7 and 18.7 microg/L, respectively. In reference to human activities, the heavy metal pollution comes from three sources: industrial emission, wastewater and solid waste. The environment such as soil, water and air were polluted by heavy metals in some cases. The contents of Cd, Cu, Pb and Zn even reach 3.16, 99.3, 84.1 and 147 mg/kg, respectively, in the soils of a wastewater irrigation zone. These contaminants pollute drinking water and food, and threaten human health. Some diseases resulting from pollution of geological and environmental origin, were observed with long-term and non-reversible effects. CONCLUSIONS: In China, the geological background level of heavy metal is low, but with the activity of humans, soil, water, air, and plants are polluted by heavy metals in some cases and even affect human health through the food chain. RECOMMENDATIONS AND OUTLOOK: To remediate and improve environmental quality is a long strategy for the polluted area to keep humans and animals healthy. Phytoremediation would be an effective technique to remediate the heavy metal pollutions. 相似文献
928.
高校财务价值链管理的特征分析与内容 总被引:1,自引:0,他引:1
在价值链概念的基础上提出高校财务价值链的特征和内容.通过如何在资金筹集价值链、资金运用价值链和资金调控价值链三个环节实现价值增值,为适时地调整高校的财务战略,合理地进行财务资源配置服务. 相似文献
929.
为改善传统电化学氧化的缺陷,将脉冲式供电引入到电化学氧化中,利用Ti/PbO2-PVDF电极,对亚甲基蓝(MB)模拟染料废水进行电化学氧化降解处理,分析初始浓度、脉冲电压、脉冲频率、占空比和NaCl浓度等因素对降解效果的影响.结果表明,当MB初始浓度为100mg/L,脉冲电压为5.5V,脉冲频率为1500Hz,占空比为50%,NaCl浓度为0.01mol/L时,降解效果最好.在相同条件下,比较脉冲与直流两种供电模式下的电化学氧化效果.结果表明脉冲模式下,90min内MB脱色率、COD去除率及电流效率分别为100%、94.5%和60.1%,均高于直流模式;脉冲模式下能耗为0.013kWh/gCOD,远小于直流模式的0.107kWh/gCOD.上述结果表明脉冲供电模式相比于直流供电模式具有明显优势. 相似文献
930.
水期权交易旨在解决水资源时空分布不均的问题,伴随着全球气候的变化,降雨量已成为影响水资源时空分布不均的重要因素。本文运用马尔科夫链进行降雨状态的划分和预测,在降雨量预测的基础上进行水期权交易相关费用的确定;将降雨量指标的预测结果融入到水期权最终交易价格的确定中,运用改进的Black-Scholes期权定价模型结合降雨量预测结果,确定水期权交易的权利金;最后运用扩展性线性支出模型进行计算结果的合理性检验,证明模型所确定的交易价格的合理性。本文以广东省为例进行案例分析,验证了将降雨量指标融入到水期权交易中的必要性,以及模型所确定的水期权交易相关费用的合理性,证明了波动水价相对于阶梯水价的优越性。考虑降雨量的水期权交易充分体现了水市场的供需关系,提高了我国水期权交易定价的科学性。 相似文献