全文获取类型
收费全文 | 967篇 |
免费 | 14篇 |
国内免费 | 29篇 |
专业分类
安全科学 | 77篇 |
废物处理 | 26篇 |
环保管理 | 200篇 |
综合类 | 238篇 |
基础理论 | 214篇 |
环境理论 | 3篇 |
污染及防治 | 156篇 |
评价与监测 | 52篇 |
社会与环境 | 34篇 |
灾害及防治 | 10篇 |
出版年
2023年 | 7篇 |
2022年 | 10篇 |
2021年 | 12篇 |
2020年 | 13篇 |
2019年 | 15篇 |
2018年 | 15篇 |
2017年 | 32篇 |
2016年 | 31篇 |
2015年 | 23篇 |
2014年 | 23篇 |
2013年 | 73篇 |
2012年 | 28篇 |
2011年 | 58篇 |
2010年 | 28篇 |
2009年 | 34篇 |
2008年 | 52篇 |
2007年 | 48篇 |
2006年 | 51篇 |
2005年 | 37篇 |
2004年 | 30篇 |
2003年 | 33篇 |
2002年 | 35篇 |
2001年 | 14篇 |
2000年 | 15篇 |
1999年 | 12篇 |
1998年 | 12篇 |
1997年 | 16篇 |
1996年 | 8篇 |
1995年 | 14篇 |
1994年 | 13篇 |
1993年 | 14篇 |
1992年 | 9篇 |
1991年 | 9篇 |
1990年 | 6篇 |
1989年 | 9篇 |
1988年 | 10篇 |
1987年 | 12篇 |
1985年 | 10篇 |
1984年 | 7篇 |
1982年 | 7篇 |
1981年 | 7篇 |
1980年 | 9篇 |
1979年 | 7篇 |
1978年 | 5篇 |
1962年 | 9篇 |
1960年 | 5篇 |
1959年 | 6篇 |
1958年 | 4篇 |
1957年 | 8篇 |
1956年 | 4篇 |
排序方式: 共有1010条查询结果,搜索用时 15 毫秒
51.
The influence of EDDS on the uptake of heavy metals in hydroponically grown sunflowers 总被引:13,自引:0,他引:13
Phytoextraction is an environmentally friendly in situ technique for cleaning up metal contaminated land. Unfortunately, efficient metal uptake by remediation plants is often limited by low phytoavailability of the targeted metals. Chelant assisted phytoextraction has been proposed to improve the efficiency of phytoextraction. Phytoremediation involves several subsequent steps: transfer of metals from the bulk soil to the root surfaces, uptake into the roots and translocation to the shoots. Nutrient solution experiments address the latter two steps. In this context we investigated the influence of the biodegradable chelating agent SS-EDDS on uptake of essential (Cu and Zn) and non-essential (Pb) metals by sunflowers from nutrient solution. EDDS was detected in shoots and xylem sap for the first time, proving that it is taken up into the above ground biomass of plants. The essential metals Cu and Zn were decreased in shoots in the presence of EDDS whereas uptake of the non-essential Pb was enhanced. We suggest that in the presence of EDDS all three metals were taken up by the non-selective apoplastic pathway as the EDDS complexes, whereas in the absence of EDDS essential metal uptake was primarily selective along the symplastic pathway. This shows that synthetic chelating agents do not necessarily increase uptake of heavy metals, when soluble concentrations are equal in the presence and absence of chelates. 相似文献
52.
Visibility: science and regulation 总被引:9,自引:0,他引:9
53.
Validation and global uncertainty of a gas chromatographic with mass spectrometry method for fenamidone analysis in grapes and wines 总被引:1,自引:0,他引:1
Abreu Sde M Herbert P Caboni P Cabras P Alves A Garau VL 《Journal of environmental science and health. Part. B》2007,42(7):817-822
Fenamidone is an imidazolinone fungicide recently introduced in viticulture practices. This work reports the validation and assessment of global uncertainty of a gas chromatographic with mass spectrometry method to analyze fenamidone in grapes and wines. This method consists in a simple and fast liquid-liquid extraction step followed by chromatographic determination. Limits of detection for fenamidone in grapes and wines were, respectively, 0.05 mg/kg and 0.06 mg/L, precision was below 9.4% and average recovery was 89 +/- 5%. In the concentration range from 0.05 to 1.00 mg/kg (or mg/L) of fenamidone, global uncertainty calculated following the EURACHEM/CITAC rules, and also by the Horwitz function, was below 25%. The EURACHEM/CITAC global uncertainty budget used gave lower estimates than those obtained from the Horwitz function. 相似文献
54.
James I. Herbert 《组织行为杂志》1990,11(6):433-446
The biographical interview method was used to study the lives of 10 black male entrepreneurs. The findings of this investigation supported Levinson's theory of developmental periods. The concept of evolving life structure was found to be vibrant and viable. Because of the impact of racial dynamics and racism, on the men's lives, two new developmental tasks of adult psychosocial development are proposed: (1) to form an individual racial identity that both acknowledges and frees the individual of their own racism and prejudices, and (2) to form an individual self-concept dedicated to the eradication of racial discrimination and racial prejudice from society. 相似文献
55.
Large-scale constructed wetlands for nutrient removal from stormwater runoff: An everglades restoration project 总被引:14,自引:0,他引:14
Mariano Guardo Larry Fink Thomas D. Fontaine Susan Newman Michael Chimney Ronald Bearzotti Gary Goforth 《Environmental management》1995,19(6):879-889
The South Florida Water Management District (SFWMD) constructed a wetland south of Lake Okeechobee to begin the process of
removing nutrients (especially phosphorus) from agricultural stormwater runoff entering the Everglades. The project, called
the Everglades Nutrient Removal (ENR) project, is a prototype for larger, similarly constructed wetlands that the SFWMD will
build as part of the Everglades restoration program. This innovative project is believed to be one of the largest agricultural
stormwater cleanup projects in the United States, if not in the world. This publication describes the ENR project's design,
construction, and proposed operation, as well as the proposed research program to be implemented over the next few years. 相似文献
56.
Graduated licensing has been implemented in many U.S. states to reduce teenage driver crash involvement. The goal is to introduce teenagers gradually to driving before allowing full, unrestricted licensure. Tennessee, one of the states that introduced graduated licensing, implemented a program to influence both driving by teenagers during the learner stage and restrictions imposed by parents after licensure. In addition to a standard welcome letter, booklets and reminder cards were mailed to parents of teenagers who had just obtained their learner's permits. The booklets and cards were designed to assist parents in becoming more actively involved in their children's driving experiences. The effects of three different approaches (welcome letter only, letter plus booklet, and letter plus booklet plus reminder cards) on parental involvement, teenage crashes, and teenage citations were assessed based on telephone interviews with parents. Although the parents said the booklets and reminder cards were helpful and should continue to be sent to other parents, there were no discernible effects on teenage practice driving and reported parental involvement during the learner stage. Nor was there any measurable influence on restrictions imposed by parents after licensure. It is unknown whether the standard welcome letter affected parental involvement, but overall supervised driving exceeded the state requirements by a substantial margin. 相似文献
57.
Biological responses of workplace particles and their association with adverse health effects on miners 总被引:2,自引:0,他引:2
Chen W Stempelmann K Rehn S Diederichs H Rehn B Bruch J 《Journal of environmental monitoring : JEM》2004,6(12):967-972
Epidemiological research has demonstrated the relationship between exposure to quartz dust and an elevated risk of pneumoconiosis and possible elevated risk of cancer. The current study was designed to evaluate the biological responses of workplace particles containing crystalline silica using an in vitro cell test. Respirable particle samples were sampled from four tin mines, where the standardized mortality ratio (SMR) for pneumoconiosis was 51.6 and SMR for lung cancer was 2.2 in dust-exposed miners. Alveolar macrophages (AM) are considered as the target cells for primary dust effects. The samples were then measured at 15, 30, 60 and 120 microg particle per 10(6) AM for cytoxicity with the release of glucuronidase, lactate dehydrogenase, for reactive oxygen damage with H(2)O(2) release, and for ability to induce fibrosis using the secretion of tumor necrosis factor-alpha (TNF-alpha). Pure quartz (DQ12) and corundum were used as controls. The results showed the samples from tin mines caused a higher cytoxicity when compared to corundum, yet lower when compared to quartz. However, reactive oxygen species release (148-177 nmol/3 x 10(5) AM in high concentration of 120 microg/10(6) AM) induced by the samples were significantly higher than that induced by quartz (57 nmol/3 x 10(5) AM) and corundum (62 nmol/3 x 10(5) AM). Furthermore, particle samples induced higher TNF-alpha secretion than corundum, the samples from Limu tin mine induced much higher TNF-alpha levels than that induced by DQ12 quartz. The results from the in vitro tests help elucidate the degree of hazard of dust particles in tin mines. The in vitro reaction patterns of AM also constitute a powerful tool to monitor biological and pathogenic responses of humans following dust particle exposure. 相似文献
58.
Pascal C. Sanginga Colletah A. Chitsike Jemimah Njuki Susan Kaaria Rogers Kanzikwera 《Natural resources forum》2007,31(4):273-285
Despite increasing interest and support for multi‐stakeholder partnerships, empirical applications of participatory evaluation approaches to enhance learning from partnerships are either uncommon or undocumented. This paper draws lessons on the use of participatory self‐reflective approaches that facilitate structured learning on processes and outcomes of partnerships. Such practice is important to building partnerships, because it helps partners understand how they can develop more collaborative and responsive ways of managing partnerships. The paper is based on experience with the Enabling Rural Innovation (ERI) in Africa programme. Results highlight the dynamic process of partnership formation and the key elements that contribute to success. These include: (i) shared vision and complementarity, (ii) consistent support from senior leadership; (iii) evidence of institutional and individual benefits; (iv) investments in human and social capital; (v) joint resources mobilization. However, key challenges require coping with high staff turnover and over‐commitment, conflicting personalities and institutional differences, high transaction costs, and sustaining partnerships with the private business sector. The paper suggests that institutionalizing multi‐stakeholder partnerships requires participatory reflective practices that help structure and enhance learning, and incrementally help in building the capacity of research and development organisations to partner better and ultimately to innovate. 相似文献
59.
E. Susan Boydstun Terry Nelson Roger B. Long 《Journal of the American Water Resources Association》1979,15(4):1086-1095
ABSTRACT: Public investments in water resource development projects are continually under scrutiny in terms of economic, environmental, and social impacts. Results of an analysis of a water development project that supplies irrigation water in Idaho are discussed in terms of the impact on income distribution and income growth 44 to 64 years after the project was initiated. Gini ratios for the rural farm population of these counties were consistently lower than they were for the United States as a whole and for the state of Idaho. In addition, income distributions tended to become more equitable over time in the water project counties. Rural farm population income growth rates were found to be similar to those for the nation as a whole. Some of the reasons for these results may be related to the tendency for income distribution to become more equitable as income increases, and the fact that average farm size is relatively small. 相似文献
60.
Mercury is released to the environment from various anthropogenic and natural sources. This work is a compilation of mercury emissions from anthropogenic sources in Ontario, Canada. The goal of our study was to identify all sources of mercury, and develop an emission inventory of anthropogenic mercury in Ontario. The result of our investigation revealed that combustion of fossil fuels and emissions from landfill sites are two primary sources of mercury to the atmosphere. Other sources of significance are emissions from waste incinerators, various industrial activities, and cement production. Total mercury emission in Ontario is estimated as 4100 kg per year. 相似文献