全文获取类型
收费全文 | 2503篇 |
免费 | 124篇 |
国内免费 | 1135篇 |
专业分类
安全科学 | 122篇 |
废物处理 | 194篇 |
环保管理 | 173篇 |
综合类 | 1391篇 |
基础理论 | 470篇 |
环境理论 | 3篇 |
污染及防治 | 1059篇 |
评价与监测 | 129篇 |
社会与环境 | 73篇 |
灾害及防治 | 148篇 |
出版年
2024年 | 1篇 |
2023年 | 39篇 |
2022年 | 125篇 |
2021年 | 118篇 |
2020年 | 76篇 |
2019年 | 76篇 |
2018年 | 84篇 |
2017年 | 97篇 |
2016年 | 165篇 |
2015年 | 182篇 |
2014年 | 206篇 |
2013年 | 216篇 |
2012年 | 190篇 |
2011年 | 232篇 |
2010年 | 191篇 |
2009年 | 174篇 |
2008年 | 196篇 |
2007年 | 119篇 |
2006年 | 144篇 |
2005年 | 86篇 |
2004年 | 97篇 |
2003年 | 91篇 |
2002年 | 107篇 |
2001年 | 77篇 |
2000年 | 87篇 |
1999年 | 84篇 |
1998年 | 91篇 |
1997年 | 83篇 |
1996年 | 76篇 |
1995年 | 63篇 |
1994年 | 35篇 |
1993年 | 42篇 |
1992年 | 27篇 |
1991年 | 21篇 |
1990年 | 12篇 |
1989年 | 6篇 |
1988年 | 9篇 |
1987年 | 11篇 |
1986年 | 6篇 |
1985年 | 6篇 |
1984年 | 3篇 |
1983年 | 4篇 |
1982年 | 1篇 |
1981年 | 5篇 |
1930年 | 1篇 |
排序方式: 共有3762条查询结果,搜索用时 15 毫秒
331.
Endocrine disrupting chemical(EDC) pollution in river-based artificial groundwater recharge using reclaimed municipal wastewater poses a potential threat to groundwater-based drinking water supplies in Beijing, China. Lab-scale leaching column experiments simulating recharge were conducted to study the adsorption, biodegradation, and transport characteristics of three selected EDCs: 17β-estradiol(E2), 17α-ethinylestradiol(EE2) and bisphenol A(BPA). The three recharge columns were operated under the conditions of continual sterilization recharge(CSR), continual recharge(CR), and wetting and drying alternative recharge(WDAR). The results showed that the attenuation effect of the EDCs was in the order of WDAR CR CSR system and E2 EE2 BPA, which followed first-order kinetics. The EDC attenuation rate constants were 0.0783, 0.0505, and 0.0479 m-1 for E2, EE2 and BPA in the CR system, respectively. The removal rates of E2, EE2, and BPA in the CR system were 98%, 96% and 92%, which mainly depended on biodegradation and were affected by water temperature.In the CR system, the concentrations of BPA, EE2, and E2 in soil were 4, 6 and 10 times higher than in the WDAR system, respectively. According to the DGGE fingerprints, the bacterial community in the bottom layer was more diverse than in the upper layer, which was related to the EDC concentrations in the water-soil system. The dominant group was found to be proteobacteria, including Betaproteobacteria and Alphaproteobacteria, suggesting that these microbes might play an important role in EDC degradation. 相似文献
332.
An activation process for developing the surface and porous structure of palygorskite/carbon(PG/C) nanocomposite using ZnC l2 as activating agent was investigated. The obtained activated PG/C was characterized by X-ray diffraction(XRD), Fourier transform infrared spectroscopy(FTIR), field-emission scanning electron microscopy(SEM), and Brunauer–Emmett–Teller analysis(BET) techniques. The effects of activation conditions were examined,including activation temperature and impregnation ratio. With increased temperature and impregnation ratio, the collapse of the palygorskite crystal structure was found to accelerate and the carbon coated on the surface underwent further carbonization. XRD and SEM data confirmed that the palygorskite structure was destroyed and the carbon structure was developed during activation. The presence of the characteristic absorption peaks of C_C and C–H vibrations in the FTIR spectra suggested the occurrence of aromatization. The BET surface area improved by more than 11-fold(1201 m2/g for activated PG/C vs. 106 m2/g for PG/C) after activation, and the material appeared to be mainly microporous. The maximum adsorption capacity of methylene blue onto the activated PG/C reached 351 mg/g. The activated PG/C demonstrated better compressive strength than activated carbon without palygorskite clay. 相似文献
333.
In order to assess the potential health risks of Hg pollution, total mercury (T–Hg) and methyl mercury (MeHg) concentrations were determined in air, dust, surface soil, crops, poultry, fish and human hair samples from an electronic waste (e-waste) recycling area in Taizhou, China. High concentrations of T–Hg and MeHg were found in these multiple matrices, and the mean concentration was 30.7 ng/m3 of T–Hg for atmosphere samples, 3.1 μg/g of T–Hg for soil, 37.6 μg/g of T–Hg for dust, 20.3 ng/g of MeHg for rice and 178.1 ng/g of MeHg for fish, suggesting that the e-waste recycling facility was a significant source of Hg. The inorganic Hg (I–Hg) levels (0.84 μg/g) in hair samples of e-waste workers were much higher than that in the reference samples. Pearson''s correlation coefficients showed that strong positive correlations (p < 0.01) between hair I–Hg and time staying in industrial area (r = 0.81) and between MeHg and fish consumption frequency (r = 0.91), imply that workers were mainly exposed to Hg vapor through long-time inhalation of contaminated air and dust, while other population mainly exposed to MeHg through high-frequency fish consumption. The estimated daily intakes of Hg showed that dietary intake was the major Hg exposure source, and Hg intakes from rice and fish were significantly higher than from any other foods. The estimated total daily intakes (TDIs) of MeHg for both children (696.8 ng/(kg·day)) and adults (381.3 ng/(kg·day)) greatly exceeded the dietary reference dose (RfD) of 230 ng/(kg·day), implying greater health risk for humans from Hg exposures around e-waste recycling facilities. 相似文献
334.
Environmental behaviors of phoxim with two formulations in bamboo forest under soil surface mulching
Yihua Liu Zhanglin Ni Runhong Mo Danyu Shen Donglian Zhong Fubin Tang 《环境科学学报(英文版)》2015,35(9):91-100
Phoxim (emulsifiable concentrate (EC) and granules (G)) has been widely used in bamboo forests. The persistence and magnitude of phoxim residues in the crop and soil must be investigated to ensure human and environmental safety. The environmental behaviors of the two formulations were investigated in a bamboo forest under soil surface mulching conditions (CP) and non-covered cultivation conditions (NCP). The half-lives of phoxim in soil under the two conditions in soil were 4.1–6.2 days (EC) and 31.5–49.5 days (G), respectively. Phoxim in EC could be leached from the topsoil into the subsoil. A minimized leaching effect was observed for G under NCP. Inversely, an enhanced leaching effect was observed for G under CP. The G formulation resulted in more parent compound (in bamboo shoots) and metabolite (in soil) residues of phoxim than in the case of EC, especially under CP conditions. In addition, the intensity and duration of the formulation effect on soil pH adjustment from G were more obvious than that from EC. Results showed that the environmental behaviors (distribution, degradation, residue) of phoxim in the bamboo forest were significantly influenced by the type of formulation. The prolongation effect from phoxim G might cause persistence and long-term environmental risk. However, bamboo shoot consumption could be considered relatively safe after applying the recommended dose of the two phoxim formulations. 相似文献
335.
唐献伟 《安全.健康和环境》2015,15(6)
采用故障树分析、鱼骨图等方法从工艺设备、设施操作、日常管理、人员等方面分析了井喷事故的途径,分析了事故发生的主要原因,提出相应的对策. 相似文献
336.
337.
338.
339.
Zheng Zhong Zeng Xun Jie Lei Dong Xiang Gao Hou Cheng Wang Zhong Ren Nan 《毒物与环境化学》2015,97(3-4):439-453
Land utilization of sewage sludge has become one of the major issues in environmental mitigation in China. This is particularly important in the Loess Plateau of Northwest China. Sludge enriched with organic matter and nutrients might effectively help to resolve the problems of silty loess soils as evidenced by porosity defect, structural alterations and absence of fertility. After sludge flows into the loess, irrigation water contains heavy metals that leach and migrate into sludge and consequently related human health risks may occur that raise concerns; and this situation needs to be rectified. The characteristics of the vertical migration and composition form change of Cu, Zn, and Cd from composted sludge to loess, and corresponding influencing factors, were investigated by performing a soil column simulation test under the leaching treatment of a one-year irrigation water capacity. Results demonstrated that: (1) composted sludge significantly improved loess fertility, and irrigation leaching transported only a small quantity of organic matter in sludge in the plough layer; (2) although some of the Cu, Zn, and Cd in composted sludge migrated to and concentrated in the middle and upper layers of the soil column during leaching, these metals were mostly retained in the plough layer; and (3) after the leaching treatment of the one-year irrigation water capacity, the compositions of Cu, Zn, and Cd (particularly Cu and Zn) in both plough layer and loess began to stabilize with low concentrations in the exudate. These findings confirmed the applicability of composted sludge in loess regions. This study provided a new insight into the sludge reuse in alkaline soils in arid and semi-arid region. 相似文献
340.
An integrated fuzzy-stochastic modeling approach for risk assessment of groundwater contamination 总被引:7,自引:0,他引:7
An integrated fuzzy-stochastic risk assessment (IFSRA) approach was developed in this study to systematically quantify both probabilistic and fuzzy uncertainties associated with site conditions, environmental guidelines, and health impact criteria. The contaminant concentrations in groundwater predicted from a numerical model were associated with probabilistic uncertainties due to the randomness in modeling input parameters, while the consequences of contaminant concentrations violating relevant environmental quality guidelines and health evaluation criteria were linked with fuzzy uncertainties. The contaminant of interest in this study was xylene. The environmental quality guideline was divided into three different strictness categories: "loose", "medium" and "strict". The environmental-guideline-based risk (ER) and health risk (HR) due to xylene ingestion were systematically examined to obtain the general risk levels through a fuzzy rule base. The ER and HR risk levels were divided into five categories of "low", "low-to-medium", "medium", "medium-to-high" and "high", respectively. The general risk levels included six categories ranging from "low" to "very high". The fuzzy membership functions of the related fuzzy events and the fuzzy rule base were established based on a questionnaire survey. Thus the IFSRA integrated fuzzy logic, expert involvement, and stochastic simulation within a general framework. The robustness of the modeling processes was enhanced through the effective reflection of the two types of uncertainties as compared with the conventional risk assessment approaches. The developed IFSRA was applied to a petroleum-contaminated groundwater system in western Canada. Three scenarios with different environmental quality guidelines were analyzed, and reasonable results were obtained. The risk assessment approach developed in this study offers a unique tool for systematically quantifying various uncertainties in contaminated site management, and it also provides more realistic support for remediation-related decisions. 相似文献