全文获取类型
收费全文 | 3949篇 |
免费 | 296篇 |
国内免费 | 1349篇 |
专业分类
安全科学 | 289篇 |
废物处理 | 191篇 |
环保管理 | 310篇 |
综合类 | 2416篇 |
基础理论 | 636篇 |
环境理论 | 1篇 |
污染及防治 | 1097篇 |
评价与监测 | 216篇 |
社会与环境 | 230篇 |
灾害及防治 | 208篇 |
出版年
2024年 | 8篇 |
2023年 | 77篇 |
2022年 | 219篇 |
2021年 | 183篇 |
2020年 | 178篇 |
2019年 | 162篇 |
2018年 | 157篇 |
2017年 | 180篇 |
2016年 | 210篇 |
2015年 | 254篇 |
2014年 | 297篇 |
2013年 | 364篇 |
2012年 | 356篇 |
2011年 | 356篇 |
2010年 | 335篇 |
2009年 | 270篇 |
2008年 | 264篇 |
2007年 | 242篇 |
2006年 | 230篇 |
2005年 | 138篇 |
2004年 | 118篇 |
2003年 | 138篇 |
2002年 | 125篇 |
2001年 | 104篇 |
2000年 | 107篇 |
1999年 | 93篇 |
1998年 | 75篇 |
1997年 | 65篇 |
1996年 | 64篇 |
1995年 | 52篇 |
1994年 | 43篇 |
1993年 | 40篇 |
1992年 | 22篇 |
1991年 | 13篇 |
1990年 | 12篇 |
1989年 | 10篇 |
1988年 | 6篇 |
1987年 | 4篇 |
1986年 | 4篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1981年 | 1篇 |
1977年 | 1篇 |
1972年 | 2篇 |
1918年 | 1篇 |
1917年 | 1篇 |
1916年 | 1篇 |
排序方式: 共有5594条查询结果,搜索用时 15 毫秒
991.
Jin Xie Xiao-Dong Niu Jiao-Jiao Xie Kai-Qiang He Meng-Dan Shi Su-Juan Yu Chun-Gang Yuan Jing-Fu Liu 《环境科学学报(英文版)》2021,33(10):1-7
The distribution and chemical speciation of arsenic (As) in different sized atmospheric particulate matters (PMs), including total suspended particles (TSP), PM10, and PM2.5, collected from Baoding, China were analyzed. The average total mass concentrations of As in TSP, PM10, and PM2.5 were 31.5, 35.3, and 54.1 µg/g, respectively, with an order of PM2.5 >PM 10 > TSP, revealing that As is prone to accumulate on fine particles. Due to the divergent toxicities of different As species, speciation analysis of As in PMs is further conducted. Most of previous studies mainly focused on inorganic arsenite (iAsIII), inorganic arsenate (iAsV), monomethylarsonate (MMA), and dimethylarsinate (DMA) in PMs, while the identification and sensitive quantification of trimethylarsine oxide (TMAO) were rarely reported. In this study, a high-performance liquid chromatography coupled to inductively coupled plasma mass spectrometry system was optimized for As speciation including TMAO in PMs. An anion exchange column was used to separate MMA, DMA and iAsV, while a cation exchange column to separate TMAO and iAsIII. Results showed that iAsV was the dominate component in all the samples, corresponding to a portion of 79.2% ± 9.3% of the total extractable species, while iAsIII, TMAO and DMA made up the remaining 21%. Our study demonstrated that iAsIII accounted for about 14.4% ± 11.4% of the total extracted species, with an average concentration of 1.7 ± 1.6 ng/m3. It is worth noting that TMAO was widely present in the samples (84 out of 97 samples), which supported the assumption that TMAO was ubiquitous in atmospheric particles. 相似文献
992.
993.
Modified clay (MC), an effective material used for the emergency elimination of algal blooms, can rapidly reduce the biomass of harmful algal blooms (HABs) via flocculation. After that, MC can still control bloom population through indirect effects such as oxidative stress, which was initially proposed to be related to programmed cell death (PCD) at molecular level. To further study the MC induced cell death in residual bloom organisms, especially identifying PCD process, we studied the physiological state of the residual Prorocentrum donghaiense. The experimental results showed that flocculation changed the physiological state of the residual cells, as evidenced by growth inhibition and increased reactive oxygen species production. Moreover, this research provides biochemical and ultrastructural evidence showing that MC induces PCD in P. donghaiense. Nuclear changes were observed, and increased caspase-like activity, externalization of phosphatidylserine and DNA fragmentation were detected in MC-treated groups and quantified. And the mitochondrial apoptosis pathway was activated in both MC-treated groups. Besides, the features of MC-induced PCD in a unicellular organism were summarized and its concentration dependent manner was proved. All our preliminary results elucidate the mechanism through which MC can further control HABs by inducing PCD and suggest a promising application of PCD in bloom control. 相似文献
994.
Sustainable method towards magnetic ordered mesoporous polymers for efficient Methylene Blue removal
The difficulty in achieving high removal efficiency for contaminants in textile wastewater over a wide range of pH impedes the progress of its treatment technique greatly. Herein, a facile and sustainable strategy was adopted for constructing magnetic ordered mesoporous polymers (M-OMPs) without the assistance of organic solvent and catalyst. The prepared M-OMPs were endowed with high special surface area and good superparamagnetism simultaneously, and exhibited high removal efficiency (>99%) for Methylene Blue (MB) within a short time (10 min) at a concentration of 50 mg/L. What's more, high removal efficiency was achieved over a wide range of pH 2-12 and the adsorption capacity for MB on M-OMPs was substantially retained even after 5 adsorption-desorption cycles, further demonstrating the application potential of M-OMPs in the decontamination of textile wastewater. 相似文献
995.
In this work, Bi2XO6 (X = W, Mo) are synthesized at different temperatures. The results of tests find the optimal temperatures of Bi2WO6 and Bi2MoO6 are 180 and 160°C (BW-180, BM-160). Then, BW-180 and BM-160 are further compounded with different contents of CuS. The results of photoelectrochemical (PEC) tests show that CuS can improve the PEC performance of semiconductor materials, and it has better performance when CuS mass fraction is 5%. These maybe the photoelectron potentials generated by CuS/Bi2XO6 (X = Mo, W) heterojunction reduce the combination of photogenerated electrons and holes. When the PEC sensor based on 5%-CuS/BW-180 detects Cr(VI), it has a linear range of 1–80 μmol/L with detection limit of 0.95 μmol/L, while the PEC sensor based on 5%-CuS/BM-160 detects Cr(VI) has a linear range of 0.5–230 μmol/L and a detection limit of 0.12 μmol/L. Thus, 5%-CuS/Bi2XO6 has potential application in hexavalent chromium detection. 相似文献
996.
997.
ZnO包覆Al_2O_3的制备表征及光催化性能研究 总被引:1,自引:0,他引:1
采用化学沉积法制备了ZnO包覆Al2O3光催化剂,并通过X射线衍射(XRD)、扫描电镜(SEM)进行了表征。在自制的光化学反应器中,以中压汞灯作光源,一定浓度的甲基橙为光催化反应模型化合物,研究了光催化剂的活性。考察了甲基橙初始浓度、催化剂加投量、pH值、温度、光照强度、反应液体积等因素对脱色率的影响。实验结果表明,ZnO包覆Al2O3复合光催化剂具有较高的光催化活性。在250W中压汞灯下光照3h,0.10g复合光催化剂能使200mL,10mg/L甲基橙溶液的脱色率达到92.21%。 相似文献
998.
Contents and sources of polycyclic aromatic hydrocarbons and organochlorine pesticides in vegetable soils of Guangzhou, China 总被引:36,自引:0,他引:36
We investigated contents, distribution and possible sources of PAHs and organochlorine pesticides (Ops) in 43 surface and subsurface soils around the urban Guangzhou where variable kinds of vegetables are grown. The results indicate that the contents of PAHs (16 US EPA priority PAHs) range from 42 to 3077 microg/kg and the pollution extent is classified as a moderate level in comparison with other investigations and soil quality standards. The ratios of methylphenanthrenes to phenanthrene(MP/P), anthracene to anthracene plus phenanthrene (An/178), benz[a]anthracene to benz[a]anthracene plus chrysene (BaA/228), indeno[1,2,3-cd]pyrene to indeno[1,2,3-cd]pyrene plus benzo[ghi]perylene (In/In+BP) suggest that the sources of PAHs in the soil samples are mixed with a dominant contribution from petroleum and combustion of fossil fuel. The correlation analysis shows that the PAHs contents are significantly related to total organic carbon contents (TOC) (R2=0.75) and black carbon contents (BC) (R2=0.62) in the soil samples. Dichlorodiphenyltrichloroethane and metabolites (DDTs) and hexachlorocyclohexanes and metabolites (HCHs) account largely for the contaminants of OPs. The concentrations of DDTs range from 3.58 to 831 microg/kg and the ratios for DDT/(DDD+DDE) are higher than 2 in some soil samples, suggesting that DDT contamination still exists and may be caused by its persistence in soils and/or impurity in the pesticide dicofol. The concentrations of HCHs are 0.19-42.3 microg/kg. 相似文献
999.
He Yao Tian Huafeng Xiang Aimin Ma Songbai Yin Duoyan Varada Rajulu A. 《Journal of Polymers and the Environment》2022,30(7):2964-2975
Journal of Polymers and the Environment - In recent years, the treatment of water pollution has been a challenging and far-reaching topic. In order to improve the adsorption performance of... 相似文献
1000.