全文获取类型
收费全文 | 10283篇 |
免费 | 1304篇 |
国内免费 | 5771篇 |
专业分类
安全科学 | 1924篇 |
废物处理 | 290篇 |
环保管理 | 1189篇 |
综合类 | 8905篇 |
基础理论 | 1974篇 |
环境理论 | 17篇 |
污染及防治 | 1750篇 |
评价与监测 | 434篇 |
社会与环境 | 536篇 |
灾害及防治 | 339篇 |
出版年
2024年 | 67篇 |
2023年 | 511篇 |
2022年 | 653篇 |
2021年 | 694篇 |
2020年 | 725篇 |
2019年 | 730篇 |
2018年 | 613篇 |
2017年 | 636篇 |
2016年 | 717篇 |
2015年 | 724篇 |
2014年 | 599篇 |
2013年 | 1091篇 |
2012年 | 1045篇 |
2011年 | 1112篇 |
2010年 | 723篇 |
2009年 | 866篇 |
2008年 | 727篇 |
2007年 | 834篇 |
2006年 | 822篇 |
2005年 | 600篇 |
2004年 | 505篇 |
2003年 | 407篇 |
2002年 | 316篇 |
2001年 | 269篇 |
2000年 | 242篇 |
1999年 | 200篇 |
1998年 | 142篇 |
1997年 | 134篇 |
1996年 | 104篇 |
1995年 | 111篇 |
1994年 | 69篇 |
1993年 | 75篇 |
1992年 | 50篇 |
1991年 | 27篇 |
1990年 | 26篇 |
1989年 | 22篇 |
1988年 | 16篇 |
1986年 | 10篇 |
1985年 | 5篇 |
1984年 | 7篇 |
1983年 | 13篇 |
1982年 | 15篇 |
1981年 | 10篇 |
1980年 | 9篇 |
1979年 | 6篇 |
1978年 | 6篇 |
1974年 | 5篇 |
1973年 | 9篇 |
1972年 | 6篇 |
1971年 | 37篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
961.
962.
五氯酚对环境污染及居民健康影响研究 总被引:2,自引:0,他引:2
中国长期以来使用五氯酚纳盐杀灭亡血吸虫的中间宿主──—钉螺.为评价它对环境的污染及居民健康危害,1990-1993年在我省开展了五氯酚环境污染及对居民健康影响研究.在研究区采集环境样品(空气、水体、土壤及底泥、蔬菜、肉、蛋、鱼等)共173份;生物材料(人血、尿)共457份,分析五氯酚浓度.结果在明,在五氯酚使用区,环境中PCP浓度稍高于对照区,而生物材料尿、血中PCP浓度明显高于对照区.全血胆碱脂酶活性用药区明显低于对照区,统计学分析有显著差异(P<0.001),证实了长期低剂量使用可造成环境及生物蓄积. 相似文献
963.
964.
Lawrence J. MacDonnell David H. Getches William C. Hugenberg 《Journal of the American Water Resources Association》1995,31(5):825-836
ABSTRACT: The waters of the Colorado River are divided among seven states according to a complex ‘Law of the River’ drawn from interstate compacts, international treaties, statutes, and regulations. The Law of the River creates certain priorities among the states and the Republic of Mexico, and in the event of a severe sustained drought, the Law of the River dictates the distribution of water and operation of the elaborate reservoir system. Earlier work indicated that there is remarkable resilience in the system for established uses of water in the Lower Basin of the Colorado River. This work shows, based on an application of the Law of the River using computer modeling of operations of facilities on the Colorado River, that there may be serious environmental consequences and related legal restraints on how the water is used in times of shortage and that the existing legal and institutional framework governing the Colorado River does not adequately address all the issues that would be raised in a severe sustained drought. Several possible legal options for dealing with drought in the context of the Law of the River are identified. 相似文献
965.
Richard S. Krannich Sean P. Keenan Michael S. Walker Donald L. Hardesty 《Journal of the American Water Resources Association》1995,31(5):851-865
ABSTRACT: Survey data collected in the San Joaquin Valley of southern California and the Grand Valley of western Colorado reveal that residents of both areas believe that a severe sustained drought is likely to occur within the next 20–25 years and that their communities would be seriously impacted by such an event. Although a severe sustained drought affecting the Colorado River Basin would cause major economic and social disruptions in these and other communities, residents express little support for water management alternatives that would require significant shifts in economic development activities or in water use and allocation patterns. In particular, residents of these areas express little support for strategies such as construction and growth moratoriums, mandatory water conservation programs, water transfers from low-to high-population areas, water marketing, or reallocations of water from agricultural to municipal/industrial uses. This rejection of water management strategies that would require a departure from “business as usual” with respect to water use and allocations severely restricts the capacity of these and similar communities to respond effectively should a severe sustained drought occur. 相似文献
966.
Taiye B. Sangoyomi Benjamin L. Harding 《Journal of the American Water Resources Association》1995,31(5):925-938
ABSTRACT: We evaluated the effects of institutional responses developed for coping with a severe sustained drought (SSD) in the Colorado River Basin on selected system variables using a SSD inflow hydrology derived from the drought which occurred in the Colorado River basin from 1579–1616. Institutional responses considered are reverse equalization, salinity reduction, minimum flow requirements, and temporary suspension of the delivery obligation of the Colorado River Compact. Selected system variables (reservoir contents, streamflows, consumptive uses, salinity, and power generation) from scenarios incorporating the drought-coping responses were compared to those from Baseline conditions using the current operating criteria. The coping responses successfully mitigated some impacts of the SSD on consumptive uses in the Upper Basin with only slight impacts on consumptive uses in the Lower Basin, and successfully maintained specified minimum streamflows throughout the drought with no apparent effect on consumptive uses. The impacts of the coping responses on other system variables were not as clear cut. We also assessed the effects of the drought-coping responses to normal and wet hydrologic conditions to determine if they were overly conservative. The results show that the rules would have inconsequential effects on the system during normal and wet years. 相似文献
967.
在研究汕头市地震、风、洪潮、火等多种灾害的危险性、成灾模式和损失估计的基础上,应用地理信息系统(GIS)技术建立可视化的计算机综合防灾系统,可以提高城市的防灾能力。本文针对基于GIS的城市综合防灾系统的建立,提出了较为具体的研究方案和实施框架,便于课题组各项研究工作的开展和统一。 相似文献
968.
E. M. White 《Journal of the American Water Resources Association》1983,19(4):649-653
ABSTRACT A stepwise multiple regression was used to evaluate the relative importance of antecedent-, event-, and high-intensity-precipitation amounts; runoff volume; and precipitation nutrient contents and concentrations in determining nutrient losses in runoff. Plots were fertilized at high, medium, and low rates and had cultivation ridges oriented up-and-down slope or on the contour. Runoff volume was the important factor in determining the loss of NO3, soluble PO4, total PO4, and soluble K ions in runoff from fallow, corn, or soybean plots. NH4-N loss was controlled mainly by the precipitation content and antecedet precipitation since fertilizer had been applied. Nutrient losses were greater from plots fertilized at the high rate and from plots with cultivation ridges oriented up-and-down slope rather than on the contour. 相似文献
969.
Ted L. Napier Elizabeth G. Bryant Steve McClaskie 《Journal of the American Water Resources Association》1983,19(5):811-819
ABSTRACT This paper examines the social impact of reservoir construction on a rural community group located in the urban fringe of a major metropolitan area in central Ohio. The study data were collected at three intervals over a ten-year period (1970, 1974, 1980). Evaluation of resident opinions in the affected community revealed significant attitude differences over time for four of the five variables measured. The findings revealed that the study group desired more social stability but had accommodated the changes experienced to date. Responses to the attitude scales showed that the people in the study group were well integrated and were closely identified with each other at all three test periods. Attitudes toward the lake project were significantly more positive over time, and in 1980 the collective community group held a basically neutral attitude about the lake. The development agency was also perceived more positively over time. 相似文献
970.
This article investigates the impact of ISO 14001 certification on the compliance with environmental regulations by Korean companies. The impact of ISO 14001 certification on the industry was studied through a questionnaire survey and the compliance of environmental regulations were investigated using government-released data. The motivation for an environment management system was a result of the current international situation and the need to maintain fair competition. ISO 14001 certification has been recognized as an essential strategy for industrial competition and to improve company/product recognition. The certified and non-certified companies' environmental regulation violation (ERV) rates were 3.5% and 11.6%, respectively, in 1997. In 1998, the ERV rate had an eight-time difference with 1.0% and 8.5% for certified and non-certified companies, respectively. Annual regulation violation rates were reduced from 3.5% in 1997 to 1.0% in 1998 with certified companies and from 11.6% in 1997 to 8.5% in 1998 with their non-certified counterparts, respectively. ISO 14001 certified companies showed more improvement than non-certified companies in regards to environmental performance. 相似文献