全文获取类型
收费全文 | 108278篇 |
免费 | 4358篇 |
国内免费 | 6502篇 |
专业分类
安全科学 | 6918篇 |
废物处理 | 3616篇 |
环保管理 | 15457篇 |
综合类 | 35157篇 |
基础理论 | 28941篇 |
环境理论 | 74篇 |
污染及防治 | 15721篇 |
评价与监测 | 6619篇 |
社会与环境 | 5249篇 |
灾害及防治 | 1386篇 |
出版年
2023年 | 896篇 |
2022年 | 2026篇 |
2021年 | 2056篇 |
2020年 | 2272篇 |
2019年 | 1918篇 |
2018年 | 2079篇 |
2017年 | 2199篇 |
2016年 | 3101篇 |
2015年 | 2986篇 |
2014年 | 3631篇 |
2013年 | 10569篇 |
2012年 | 3875篇 |
2011年 | 4082篇 |
2010年 | 4743篇 |
2009年 | 4845篇 |
2008年 | 3297篇 |
2007年 | 3217篇 |
2006年 | 3680篇 |
2005年 | 3264篇 |
2004年 | 3244篇 |
2003年 | 2912篇 |
2002年 | 2410篇 |
2001年 | 2756篇 |
2000年 | 2339篇 |
1999年 | 1678篇 |
1998年 | 1412篇 |
1997年 | 1379篇 |
1996年 | 1515篇 |
1995年 | 1597篇 |
1994年 | 1493篇 |
1993年 | 1335篇 |
1992年 | 1353篇 |
1991年 | 1298篇 |
1990年 | 1248篇 |
1989年 | 1218篇 |
1988年 | 1057篇 |
1987年 | 992篇 |
1986年 | 995篇 |
1985年 | 1060篇 |
1984年 | 1159篇 |
1983年 | 1169篇 |
1982年 | 1177篇 |
1981年 | 1095篇 |
1980年 | 944篇 |
1979年 | 928篇 |
1978年 | 823篇 |
1977年 | 720篇 |
1976年 | 638篇 |
1973年 | 634篇 |
1972年 | 632篇 |
排序方式: 共有10000条查询结果,搜索用时 171 毫秒
11.
Pradhan Umesh Kumar Ram Anirudh Sahu Balaram P. B. Udayakrishnan Lonkar Saurabh Kumbhar Laxmankumar 《Environmental science and pollution research international》2021,28(36):49725-49742
Environmental Science and Pollution Research - Nutrient source and transport study in tropical creeks adjacent to megacities are sparse on a regional and global scale. High-frequency chemical data... 相似文献
12.
Morsheda Akhter Sagar Kumar Dutta Palash Kumar Dhar Jamil Ahmed Mohammed Nazrul Islam Khan Md. Khairul Amin Jahidul Islam 《环境质量管理》2023,32(4):149-160
Catalytic activity of spinel ferrite in breaking down toxic dye materials are promising due to their uniqueness. In this study, aluminum-doped copper zinc ferrite, Cu0.4Zn0.6-xAlxFe2O4 (x = 0.0, 0.2, 0.4, 0.6), a catalyst for toxic dye degradation is synthesized through chemical co-precipitation route. The formation of the spinel ferrite catalyst is initially confirmed by Fourier transform infrared spectra, which shows the frequency of metal-oxygen bond vibration at 539 and 427 cm−1 attributed to the tetrahedral and octahedral sites respectively. Higher intensity sharp peak of X-ray diffraction for (311) plane is the evidence for the phase purity and the formation of spinel ferrite. The crystallite size is found to decrease with the increase of Al3+ ion. The surface structure of the obtained particles is investigated using a scanning electron microscope. Analyses of the material's magnetic characteristics using a vibrating sample magnetometer (VSM) revealed that it is, in fact, a soft magnet, as evidenced by the loop of its hysteresis, which is narrow. The catalytic degradation of methylene blue dye under the mechanism of the photo-Fenton process is studied with the obtained spinel ferrites and the result is found to be as high as 96.5%. The process follows pseudo-second order kinetics and the Langmuir isotherm. 相似文献
13.
Russian Journal of Ecology - A new method for assessing the response of biota to climatic changes in the ecosystem has been tested. In the Central Forest Natural Biosphere Reserve, the average... 相似文献
14.
The Science of Nature - We present the first study that compares phenological variation in parasite load and inflammatory response in a lizard with asynchronous male and female gonadal cycles.... 相似文献
15.
以汉江源区(李家河村)和嘉陵江源区(杨家山村)黄土剖面为研究对象,对其粒度、元素组成、团聚体等进行分析与对比,探究两地土壤成土强度与系统分类归属.结果表明两江源区的土壤风化成土特征级类明显不同:(1)两地土壤团聚体主要分布在0.25~1 mm范围内,但汉江源区(LJH)土壤上部的大团聚体含量R0.25值(83.73%)、平均重量直径MWD值(2.17)和几何平均直径GMD值(1.11)均大于嘉陵江源区(YJS)的土壤(其R0.25值为69.81%,MWD和GMD值分别为1.06、0.47),团聚体稳定性更强,而剖面中下部则相反,土体稳定性弱于后者;(2)嘉陵江源区土壤的风化程度仅达到低等向中等强度过渡阶段,与其相比,汉江源区土壤的钾钠比值和残积指数较高、硅铝铁率和淋溶系数较低,钙、钠等易溶元素风化淋失更强,产生的富铝黏土矿物更多,达到中等风化强度,故后者风化成土强度远大于前者;(3)在土壤系统分类中,汉江源区黄土母质发育的土壤可归为斑纹简育湿润淋溶土,嘉陵江源区土壤可归为普通钙积干润淋溶土. 相似文献
16.
有机固废中碳、磷、硫及重金属等元素赋存形态是决定其环境行为、反应活性及资源化再利用的关键因素.同步辐射光谱技术可以在分子水平、微纳米尺度原位表征有机固废中碳、磷、硫、重金属等元素赋存形态、结合位点、微观结构,为深入阐明有机固废环境行为、反应机制提供直接的证据.概述了X射线吸收光谱、微束X射线荧光光谱等同步辐射光谱技术在有机固废污染控制与资源化研究的中应用进展,并对同步辐射光谱技术在该领域应用前景和发展趋势进行了展望,以期为有机固废资源化再利用及其污染控制等研究提供参考. 相似文献
17.
18.
Safar Korai M. Bux Mahar R. Aslam Uqaili M. 《Journal of Material Cycles and Waste Management》2018,20(2):1239-1247
Journal of Material Cycles and Waste Management - Power generation from municipal solid waste plays significant role to mitigate the environmental pollution. The power generation potential of... 相似文献
19.
20.
Progress and challenges in consolidating the management of Amazonian protected areas and indigenous territories 下载免费PDF全文
Effective management refers to the ability of a protected area or indigenous territory to meet its objectives, particularly as they relate to the protection of biodiversity and forest cover. Effective management is achieved through a process of consolidation, which among other things requires legally protecting sites, integrating sites into land‐use planning, developing and implementing management and resource‐use plans, and securing long‐term funding to pay for recurrent costs. Effectively managing all protected areas and indigenous territories in the Amazon may be needed to avoid a deforestation tipping point beyond which regional climatic feedbacks and global climate change interact to catalyze irreversible drying and savannization of large areas. At present, protected areas and indigenous territories cover 45.5% (3.55 million km2) of the Amazon, most of the 60–70% forest cover required to maintain hydrologic and climatic function. Three independent evaluations of a long‐term large‐scale philanthropic initiative in the Amazon yielded insights into the challenges and advances toward achieving effective management of protected areas and indigenous territories. Over the life of the initiative, management of sites has improved considerably, particularly with respect to management planning and capacity building, but few sites are effectively managed and many lack sufficient long‐term financing, adequate governance, support of nongovernmental organizations, and the means to withstand economic pressures. The time and money required to complete consolidation is still poorly understood, but it is clear that philanthropic funding is critical so long as essential funding needs are not met by governments and other sources, which could be on the order of decades. Despite challenges, it is encouraging that legal protection has expanded greatly and management of sites is improving steadily. Management of protected areas in other developing countries could be informed by improvements that have occurred in Amazonian countries. 相似文献