全文获取类型
收费全文 | 6971篇 |
免费 | 433篇 |
国内免费 | 2557篇 |
专业分类
安全科学 | 580篇 |
废物处理 | 392篇 |
环保管理 | 556篇 |
综合类 | 4146篇 |
基础理论 | 1126篇 |
污染及防治 | 2215篇 |
评价与监测 | 318篇 |
社会与环境 | 300篇 |
灾害及防治 | 328篇 |
出版年
2024年 | 17篇 |
2023年 | 137篇 |
2022年 | 382篇 |
2021年 | 337篇 |
2020年 | 270篇 |
2019年 | 250篇 |
2018年 | 257篇 |
2017年 | 359篇 |
2016年 | 347篇 |
2015年 | 381篇 |
2014年 | 526篇 |
2013年 | 726篇 |
2012年 | 569篇 |
2011年 | 661篇 |
2010年 | 462篇 |
2009年 | 422篇 |
2008年 | 509篇 |
2007年 | 420篇 |
2006年 | 412篇 |
2005年 | 267篇 |
2004年 | 210篇 |
2003年 | 259篇 |
2002年 | 269篇 |
2001年 | 195篇 |
2000年 | 219篇 |
1999年 | 181篇 |
1998年 | 153篇 |
1997年 | 147篇 |
1996年 | 120篇 |
1995年 | 120篇 |
1994年 | 78篇 |
1993年 | 76篇 |
1992年 | 78篇 |
1991年 | 50篇 |
1990年 | 34篇 |
1989年 | 13篇 |
1988年 | 10篇 |
1987年 | 7篇 |
1986年 | 7篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1981年 | 1篇 |
1974年 | 1篇 |
1973年 | 5篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有9961条查询结果,搜索用时 453 毫秒
311.
Jinzhao Huang Song Liu Lei Kuang Yongdan Zhao Tao Jiang Shiyou Liu Xijin Xu 《环境科学学报(英文版)》2013,25(12):2487-2491
An efficient photocatalyst was fabricated by assembling quantum dots (QDs) onto one-dimensionally-ordered ZnO nanorods, and the photocatalytic properties for Methyl Orange degradation were investigated by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, UV-Vis-NIR absorption spectroscopy and photoluminescence. The results indicate that the catalyst with assembled QDs is more favorable for the degradation than the pristine ZnO nanorods. The QDs with core-shell structure lower the photocatalytic ability due to the higher carder transport barrier of the ZnS shell layer. Besides its degradation efficiency, the photocatalyst has several advantages given that the one-dimensionally-ordered ZnO nanorods have been grown directly on indium tin oxide substrates. The article provides a new method to design an effective and easily recyclable photocatalyst. 相似文献
312.
Xiangyun Zhong Shiyong Wu Yang Liu Zhenning Zhao Yaru Zhang Jinfeng Bai Jun Xu Bai Xi 《环境科学学报(英文版)》2013
The evolvement of morphology and structure of the coal with different metamorphic degrees during coking process in the vertical furnace was investigated by infrared Image detector. Moreover, the temperature distribution in the radial direction and the crack formation were also studied in heating process. The results show that the amount of crack and the shrinkage level of char decrease with the coal rank rising. In addition, the initial temperature of crack formation for char increases with the coal rank rising. 相似文献
313.
Waste oyster shell as a kind of active filler to treat the combined wastewater at an estuary 总被引:3,自引:0,他引:3
Hongbing Luo Gu Huang Xiaoying Fu Xiaoling Liu Daocai Zheng Jian Peng Ke Zhang Bo Huang Liangqian Fan Fenghui Chen Xiubo Sun 《环境科学学报(英文版)》2013,25(10):2047-2055
Estuaries have been described as one of the most difficult environments on Earth. It is difficult to know how to treat the combined wastewater in tidal rivers at the estuary, where the situation is very different from ordinary fresh water rivers. Waste oyster shell was used as the active filler in this study in a bio-contact oxidation tank to treat the combined wastewater at the Fengtang Tidal River. With a middle-experimental scale of 360 ma/day, the average removal efficiency of COD, BOD, NH3-N, TP and TSS was 80.05%, 85.02%, 86.59%, 50.58% and 85.32%, respectively, in this bio-contact oxidation process. The living microbes in the biofilms on the waste oyster shell in this bio-contact oxidation tank, which were mainly composed of zoogloea, protozoa and micro-metazoa species, revealed that waste oyster shell as the filler was suitable material for combined wastewater degradation. This treatment method using waste oyster shell as active filler was then applied in a mangrove demonstration area for water quality improvement near the experiment area, with a treatment volume of 5 × 10^3 m^3/day. Another project was also successfully applied in a constructed wetland, with a wastewater treatment volume of 1 ×10^3 m^3/day. This technology is therefore feasible and can easily be applied on a larger scale, 相似文献
314.
Shiming Ding Di Xu Xiuling Bai Shuchun Yao Chengxin Fan Chaosheng Zhang 《环境科学学报(英文版)》2013,25(5):925-932
The understanding of organic phosphorus(P) dynamics in sediments requires information on their species at the molecular level,but such information in sediment profiles is scarce.A sediment profile was selected from a large eutrophic lake,Lake Taihu(China),and organic P species in the sediments were detected using solution phosphorus-31 nuclear magnetic resonance spectroscopy(31 P NMR) following extraction of the sediments with a mixture of 0.25 mol/L NaOH and 50 mmol/L EDTA(NaOH-EDTA) solution.The results showed that P in the NaOH-EDTA extracts was mainly composed of orthophosphate,orthophosphate monoesters,phospholipids,DNA,and pyrophosphate.Concentrations of the major organic P compound groups and pyrophosphate showed a decreasing trend with the increase of depth.Their half-life times varied from 3 to 27 years,following the order of orthophosphate monoesters > phospholipids DNA > pyrophosphate.Principal component analysis revealed that the detected organic P species had binding phases similar to those of humic acid-associated organic P(NaOH-NRP HA),a labile organic P pool that tends to transform to recalcitrant organic P pools as the early diagenetic processes proceed.This demonstrated that the depth attenuation of the organic P species could be partly attributed to their increasing immobilization by the sediment solids,while their degradation rates should be significantly lower than what were suggested in previous studies. 相似文献
315.
介绍了采用溶胶凝胶法合成新型的复合材料-磁性的γ-Fe_2O_3膨胀石墨(MEG)复合材料。通过采用X-射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)以及X-光电子能谱仪(XPS)对该复合材料MEG进行了表征,结果表明MEG中γ一Fe_2O_3的粒径约为50nm,而且其中γ一Fe_2O_3和膨胀石墨通过C=O相互作用。复合材料MEG作为新型的六价铬吸附剂,通过吸附时间、初始溶液的pH值以及再生性对该吸附过程进行了考察。结果表明:在40 min内MEG吸附六价铬的过程基本达到平衡;在初始溶液的pH为3.5时,MEG对六价铬的最大吸附量可以达到16.4mg/g;而且该复合材料MEG重复使用3次后吸附效果基本没有下降。因此,复合材料MEG对于废水中六价铬的处理有选择性吸附作用,而且初始溶液的pH值对其吸附过程起着重要作用。 相似文献
316.
以重铬酸钾为供试物,用固体平板法和还原实验对铬(Ⅵ)土著还原菌进行筛选,用载片培养法、革兰氏染色法、鞭毛染色法、芽孢染色法对还原菌做初步的鉴定,共筛选出16株铬(Ⅵ)土著还原菌,并挑选出还原率相对较高的Z2(35.2%)、Z3(45.2%)、Z4(38.6%)、X8(30.4%)、X10(29.4%)作为铬(Ⅵ)的优势还原菌株。经初步鉴定,土著真菌Z2为黑曲霉(Aspergillusniger),Z3、Z4为镰刀菌属(Fusariumsp.),土著细菌X8、X10为芽孢杆菌(Bacillussp.)。实验的方法和成果将为铬(Ⅵ)污染土壤微生物治理技术的推广应用提供技术支持。 相似文献
317.
318.
319.
320.
采用数理统计方法,并结合现行和2012年2月新颁布的《环境空气质量标准》以及相应的空气质量评价方法,对实测数据进行分析和研究,结果表明:新、旧两种标准评价下均反映出颗粒物污染是影响研究地空气质量状况的主要原因.并且由于新标准比现行标准更为严格,使得空气质量综合评价结果中新标准评价下的空气质量优良天数比例少于现行标准评价下的优良天数比例. 相似文献