全文获取类型
收费全文 | 1545篇 |
免费 | 84篇 |
国内免费 | 279篇 |
专业分类
安全科学 | 113篇 |
废物处理 | 74篇 |
环保管理 | 253篇 |
综合类 | 697篇 |
基础理论 | 232篇 |
污染及防治 | 409篇 |
评价与监测 | 39篇 |
社会与环境 | 63篇 |
灾害及防治 | 28篇 |
出版年
2024年 | 3篇 |
2023年 | 38篇 |
2022年 | 36篇 |
2021年 | 55篇 |
2020年 | 56篇 |
2019年 | 67篇 |
2018年 | 40篇 |
2017年 | 47篇 |
2016年 | 62篇 |
2015年 | 67篇 |
2014年 | 70篇 |
2013年 | 143篇 |
2012年 | 145篇 |
2011年 | 123篇 |
2010年 | 61篇 |
2009年 | 79篇 |
2008年 | 66篇 |
2007年 | 116篇 |
2006年 | 111篇 |
2005年 | 77篇 |
2004年 | 67篇 |
2003年 | 50篇 |
2002年 | 48篇 |
2001年 | 40篇 |
2000年 | 52篇 |
1999年 | 31篇 |
1998年 | 39篇 |
1997年 | 20篇 |
1996年 | 2篇 |
1995年 | 8篇 |
1994年 | 17篇 |
1993年 | 8篇 |
1992年 | 9篇 |
1991年 | 5篇 |
1990年 | 2篇 |
1989年 | 6篇 |
1988年 | 6篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 5篇 |
1983年 | 4篇 |
1982年 | 5篇 |
1981年 | 4篇 |
1979年 | 2篇 |
1972年 | 2篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有1908条查询结果,搜索用时 78 毫秒
661.
The term governance describes the multitude of actors and processes that lead to collectively binding decisions. The term
risk governance translates the core principles of governance to the context of risk-related policy making. We aim to delineate
some basic lessons from the insights of the other articles in this special issue for our understanding of risk governance.
Risk governance provides a conceptual as well as normative basis for how to cope with uncertain, complex and/or ambiguous
risks. We propose to synthesize the breadth of the articles in this special issue by suggesting some changes to the risk governance
framework proposed by the International Risk Governance Council (IRGC) and adding some insights to its analytical and normative
implications. 相似文献
662.
663.
曹岚 《中国环境管理干部学院学报》2012,(6):73-76
“教学做一体化”课程有利于理论教学与实践教学相结合,有利于高职学校长期健康的发展。“教学做一体化”教学模式是基于实际工作过程导向,以工作中典型项目任务引领,激发学生兴趣,以满足培养高等技能型人才的迫切需要。一体化课程的构建应通过项目设立、建立小组、实施、反馈等环节完成。 相似文献
664.
Amber Spackman Jones Jeffery S. Horsburgh Nancy O. Mesner Ronald J. Ryel David K. Stevens 《Journal of the American Water Resources Association》2012,48(6):1258-1275
Abstract: The determination of sediment and nutrient loads is typically based on the collection and analysis of grab samples. The frequency and regularity of traditional sampling may not provide representation of constituent loading, particularly in systems with flashy hydrology. At two sites in the Little Bear River, Utah, continuous, high‐frequency turbidity was used with surrogate relationships to generate estimates of total phosphorus and total suspended solids concentrations, which were paired with discharge to estimate annual loads. The high frequency records were randomly subsampled to represent hourly, daily, weekly, and monthly sampling frequencies and to examine the effects of timing, and resulting annual load estimates were compared to the reference loads. Higher frequency sampling resulted in load estimates that better approximated the reference loads. The degree of bias was greater at the more hydrologically responsive site in the upper watershed, which required a higher sampling frequency than the lower watershed site to achieve the same level of accuracy in estimating the reference load. The hour of day and day of week of sampling impacted load estimation, depending on site and hydrologic conditions. The effects of sampling frequency on the determination of compliance with a water quality criterion were also examined. These techniques can be helpful in determining necessary sampling frequency to meet the objectives of a water quality monitoring program. 相似文献
665.
Aquatic macrophytes play an important role in the structural and functional aspects of aquatic ecosystems by altering water
movement regimes, providing shelter to fish and aquatic invertebrates, serving as a food source, and altering water quality
by regulating oxygen balance, nutrient cycles, and accumulating heavy metals. The ability to hyperaccumulate heavy metals
makes them interesting research candidates, especially for the treatment of industrial effluents and sewage waste water. The
use of aquatic macrophytes, such as Azolla with hyper accumulating ability is known to be an environmentally friendly option to restore polluted aquatic resources.
The present review highlights the phytoaccumulation potential of macrophytes with emphasis on utilization of Azolla as a promising candidate for phytoremediation. The impact of uptake of heavy metals on morphology and metabolic processes
of Azolla has also been discussed for a better understanding and utilization of this symbiotic association in the field of phytoremediation. 相似文献
666.
Stephen F. Lincoln 《Ambio》2012,41(8):841-850
Climate change is occurring largely as a result of increasing CO2 emissions whose reduction requires greater efficiency in energy production and use and diversification of energy sources away from fossil fuels. These issues were central to the United Nation climate change discussions in Durban in December 2011 where it was agreed that a legally binding agreement to decrease greenhouse gas emissions should be reached by 2015. In the interim, nations were left with the agreement reached at the analogous 2009 Copenhagen and 2010 Cancun meetings that atmospheric CO2 levels should be constrained to limit the global temperature rise to 2 °C. However, the route to this objective was largely left to individual nations to decide. It is within this context that options for reduction in the 95 % fossil fuel dependency and high CO2 emissivity of the Australian energy profile using current technologies are considered. It is shown that electricity generation in particular presents significant options for changing to a less fossil fuel dependent and CO2 emissive energy profile. 相似文献
667.
The water-soluble fraction (WSF) of petroleum contains a mixture of polycyclic aromatic hydrocarbons, volatile hydrocarbons, phenols, and heterocyclic compounds, considered deleterious to aquatic biota. Marine “pejerrey” Odontesthes argentinensis (Teleostei: Atherinopsidae) has a great commercial importance in local fisheries and a high potential for aquaculture. The aim of this study was to evaluate the histopathological effects in “pejerrey” larvae exposed to different concentrations of petroleum WSF. The chronic toxicity test was conducted with newly hatched larvae exposed for 21 days to sublethal concentrations of WSF (2.5, 5, 10, and 20 % of WSF), plus one control. Survival and growth were significantly lower in the highest concentration. Several histopathological changes were found in the gills (e.g., hyperplasia, aneurisms, edema, and necrosis), kidney (e.g., nuclear alterations, decrease in the hematopoietic cells), and liver (e.g., hypertrophy, karyorrhexis, and karyopyknosis). An index of branchial lesion was proposed to standardize gill lesions to different pollutants. 相似文献
668.
The northern reef of Yongxing Island, the largest reef island of the Xisha Islands in the South China Sea, was in good condition with significant cover of scleractinian corals until 2002. Surveys in 2008 and 2010, however, found that coral coverage had declined rapidly and severely, implying that catastrophic coral mortality occurred during the past 8 years. A blackish mat was observed covering live and dead corals in both 2008 and 2010 that was identified as an encrusting sponge, Terpios hoshinota, by special surface morphology and spicule structure. In addition, spicule residues were found on the surface of long-dead corals, indicating a previous invasion of T. hosinota. T. hoshinota is referred to as the "black disease" because it rapidly overgrows and kills corals. Our evidence indicates that outbreaks of black disease are at least partially responsible for the massive coral mortality at the northern reef of Yongxing Island over the past 8 years, although human activities and heat-related coral bleaching cannot be discounted as minor causes for this coral decline. 相似文献
669.
670.
Exposure to persistent organic pollutants (POPs), such as polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethane (p,p′-DDE), and hexachlorobenzene (HCB) continues to be of concern due to their ubiquitous distribution and high persistence. Current toxicant body burden is still a primary concern within the Akwesasne Mohawk Nation since other studies conducted within the community have shown relationships between these POPs and endocrine disruption.In this article we describe the levels of these toxicants in young adults of the Akwesasne Mohawk Nation between the ages of 17 and 21 years of age (mean age 18.1 years), and investigate potential influences of their current body burden. Seventeen congeners in fourteen chromatographic peaks were detected in 50% or more of the individuals sampled (geometric mean [GM] of the sum of these congeners = 0.43 ppb). Congeners 118, 138[+163 + 164] and 153 had the highest rate of detection (?98%) within the Akwesasne young adults. Of the other organochlorines, HCB (GM = 0.04 ppb) and p,p′-DDE (GM = 0.38 ppb) were found in 100% and 99% of the sample respectively.Significantly higher levels of PCBs were found among individuals who were breastfed as infants, were first born, or had consumed local fish within the past year. When compared to levels of p,p′-DDE, HCB, and 13 specific congeners reported by the CDC for youth between the ages of 12 and 19 years, the geometric means of several congeners (CBs 99, 105, 110, and 118) among the Akwesasne were higher than the reported CDC 90th percentile. In contrast, levels of CB 28 in Akwesasne young adults were ∼50% or less than those of the CDC cohort. p,p′-DDE and HCB levels were generally higher in the CDC cohort (GM of 0.516 and 0.065 ppb, respectively for Mohawks vs. 2.51 and 0.123, respectively, for CDC). Concentrations of non-persistent PCBs among this sample of Akwesasne young adults were higher than those reported by the CDC suggesting continued exposure, but lower than those associated with severe contamination.Additional research into the concentration trends of individual PCB congeners within Akwesasne youth and young adults is warranted to further improve our insight into the determinants and influences of organochlorine concentrations within members of the Akwesasne community. 相似文献