全文获取类型
收费全文 | 2190篇 |
免费 | 303篇 |
国内免费 | 781篇 |
专业分类
安全科学 | 281篇 |
废物处理 | 68篇 |
环保管理 | 206篇 |
综合类 | 1653篇 |
基础理论 | 329篇 |
污染及防治 | 399篇 |
评价与监测 | 131篇 |
社会与环境 | 116篇 |
灾害及防治 | 91篇 |
出版年
2024年 | 23篇 |
2023年 | 66篇 |
2022年 | 175篇 |
2021年 | 152篇 |
2020年 | 141篇 |
2019年 | 100篇 |
2018年 | 102篇 |
2017年 | 122篇 |
2016年 | 123篇 |
2015年 | 134篇 |
2014年 | 147篇 |
2013年 | 182篇 |
2012年 | 225篇 |
2011年 | 198篇 |
2010年 | 181篇 |
2009年 | 176篇 |
2008年 | 164篇 |
2007年 | 186篇 |
2006年 | 145篇 |
2005年 | 93篇 |
2004年 | 92篇 |
2003年 | 71篇 |
2002年 | 56篇 |
2001年 | 56篇 |
2000年 | 44篇 |
1999年 | 33篇 |
1998年 | 22篇 |
1997年 | 18篇 |
1996年 | 11篇 |
1995年 | 4篇 |
1994年 | 8篇 |
1993年 | 8篇 |
1992年 | 5篇 |
1991年 | 5篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1982年 | 1篇 |
1977年 | 2篇 |
1971年 | 1篇 |
排序方式: 共有3274条查询结果,搜索用时 15 毫秒
801.
Ling Zunbin Sun Deyong Wang Shengqiang Qiu Zhongfeng Huan Yu Mao Zhihua He Yijun 《Environmental science and pollution research international》2020,27(7):6872-6885
Environmental Science and Pollution Research - Colored dissolved organic matter (CDOM) is the main constituent of dissolved organic matter (DOM), also a key indicator of water quality conditions.... 相似文献
802.
803.
804.
1月3日青海玉树发生特大交通事故,死亡55人。5日甘肃一民营石化公司发生毒气中毒事故,3人死亡。7日福建发生特大交通事故,死亡28人。10日美军救援直升机在印尼坠毁。11日山西襄汾县花炮厂发生爆炸事故,死亡25人,伤9人。13日澳大利亚发生20年来最严重森林火灾,10人死亡。14日长沙市一化工厂发生爆炸,3死2伤。16日四川宜宾旧楼爆破打孔时发生坍塌,8人遇难。18日北京一化工厂发生爆炸事故,7人受轻伤。 相似文献
805.
806.
Recycling and reusing recyclables is an important way to solve the municipal solid waste (MSW) problem. As the collection of solid waste takes up the largest percentage of MSW management budgets, improving the collection of recyclables is important. Since the decline of government-run waste buying depots in the late 1980s, the collection of recyclables from households and waste deposit sites in China is done by buyers with small informal bases and waste pickers, who are usually unskilled rural people who have come to the cities. Because of this, the current system is seen to have social problems. So, the recyclable collection system has both social as well as economic significance. China is in the process of rapid industrialization and urbanization, and a new mode of community collection system is emerging. It operates by market mechanisms, with waste collection companies that are supported by the municipal government, establishing recycle service sites, and employing workers to buy recyclables door-to-door. This paper is a case study of the new system in the Haidian District, Beijing. It summarizes the system, compares it to experiences in other countries and discusses whether the new approach contributes to resources recycling in China. 相似文献
807.
Fluroxypyr (4-amino-3,5-dichloro-6-fluoro-2-pyridinyl-1-methylheptyl ester) is a widely used herbicide for controlling weeds, fungi, and insects. However, extensive use of the herbicide has led to its high accumulation in ecosystems and contamination to soils and crops. Environmental behaviors and fate of herbicides are dependent on many physiochemical and biological factors. Whether fluroxypyr is significantly affected and how it is degraded under the environmental conditions is largely unknown. The present study investigated the effects of soil microbe, soil type, dissolved organic matter (DOM), temperature, soil moisture, and surfactant on fluroxypyr degradation in soils. Application of DOM derived from sludge and straw to fluroxypyr-contaminated soils increased degradation of fluroxypyr. Environmental factors such as temperature, moisture, soil microbe and soil type could affect the rate of fluroxypyr dissipation. Also, the microorganism affected the degradation of fluroxypyr. Analysis by gas chromatography-mass revealed that the reaction in soils might include the removal of 1-methylheptyl ester to generate fluroxypyr acid (4-amino-3,5-dichloro-6-fluoro-2-pyridiny). Our results provided initial data that a set of biological and physiochemical factors coordinately regulates the decay of fluroxypyr in soils. 相似文献
808.
The effects of intensive aquaculture on nutrient residence time and transport in a coastal embayment 总被引:1,自引:0,他引:1
Bing Wang Ling Cao Fiorenza Micheli Rosamond L. Naylor Oliver B. Fringer 《Environmental Fluid Mechanics》2018,18(6):1321-1349
Aquaculture in many countries around the world has become the biggest source of seafood for human consumption. While it alleviates the pressure on wild capture fisheries, the long-term impacts of large-scale, intensive aquaculture on natural coastal systems need to be better understood. In particular, aquaculture may alter habitat and exceed the carrying capacity of coastal marine ecosystems. In this paper, we develop a high-resolution numerical model for Sanggou Bay, one of the largest kelp and shellfish aquaculture sites in Northern China, to investigate the effects of aquaculture on nutrient transport and residence time in the bay. Drag from aquaculture is parameterized for surface infrastructure, kelp canopies, and bivalve cages. A model for dissolved inorganic nitrogen (DIN) includes transport, vertical turbulent mixing, sediment and bivalve sources, and a sink due to kelp uptake. Test cases show that, due to drag from the dense aquaculture and thus a reduction of horizontal transport, kelp production is limited because DIN from the Yellow Sea is consumed before reaching the interior of the kelp farms. Aquaculture drag also causes an increase in the nutrient residence time from an average of 5 to 10 days in the middle of Sanggou Bay, and from 25 to 40 days in the shallow inner bay. Low exchange rates and a lack of DIN uptake by kelp make these regions more susceptible to phytoplankton blooms due to high nutrient retention. The risk is further increased when DIN concentrations rise due to river inflows. 相似文献
809.
Ronghui Ye Chenming Zhang Jun Kong Guangqiu Jin Hongjun Zhao Zhiyao Song Ling Li 《Environmental Fluid Mechanics》2018,18(6):1379-1411
This paper proposes a new high-resolution finite volume method for solving the two-dimensional (2D) solute transport equation using an unstructured mesh. A new simple r-factor algorithm is introduced into the Total Variation Diminishing flux limiter to achieve a more efficient yet accurate high-resolution scheme for solving the advection term. To avoid the physically-meaningless negative solutions resulted from using the Green–Gauss theorem, a nonlinear two-point flux approximation scheme is adopted to deal with the anisotropic diffusion term. The developed method can be readily coupled with a two-dimensional finite-volume-based flow models under unstructured triangular mesh. By integrating with the ELCIRC flow model, the proposed method was verified using three idealized benchmark cases (i.e., advection of a circle-shaped solute field, advection in a cyclogenesis flow field and transport of a initially square-shaped solute plume), and further applied to simulate the non-reactive solute transport process driven by irregular tides in the Deep Bay, eastern Pearl River Estuary of China. These cases are also simulated by models using other existing methods, including different r-factor for advection term and the Green–Gauss theorem for diffusion term. The comparison between the results from the new method and those from other existing methods demonstrated the new method could describe advection induced concentration shock and discontinuities, and anisotropic diffusion at high resolution without providing spurious oscillations and negative values. 相似文献
810.
Kit Wayne Chew Pau Loke Show Yee Jiun Yap Joon Ching Juan Siew Moi Phang Tau Chuan Ling Jo-Shu Chang 《Frontiers of Environmental Science & Engineering》2018,12(4):2
Various pretreatments methods including sonication and grinding were performed on red seaweed Gelidium amansii for the subsequent extraction of agarose. The agarose products are usually extracted from agar powder products from seaweeds. In this study, the agarose was extracted using a direct polyethylene glycol (PEG) method without the need to first process the agar from seaweed. The agar extract was frozen then thawed and mixed directly with PEG solution to precipitate the agarose. The quality of agarose obtained was evaluated through physico-chemical properties analysis which includes spectral technique (FTIR), melting and boiling point, gel strength and sulfate content. These properties were compared with a non-pretreated sample and it was found that the addition of pretreatment steps improved the quality of agarose but gave a slightly lower yield. The gel strength of pretreated samples was much higher and the sulfate content was lower compared to non-pretreated samples. The best pretreatment method was sonication which gave gel strength of 742 g cm-2 and sulfate content of 0.63%. The extraction of agarose can be further improved with the use of different neutralizing agents. Pretreating the seaweed shows potential in improving the quality of agarose from seaweed and can be applied for future extraction of the agarose.
相似文献