全文获取类型
收费全文 | 7644篇 |
免费 | 133篇 |
国内免费 | 893篇 |
专业分类
安全科学 | 306篇 |
废物处理 | 490篇 |
环保管理 | 656篇 |
综合类 | 1969篇 |
基础理论 | 1518篇 |
环境理论 | 3篇 |
污染及防治 | 2698篇 |
评价与监测 | 534篇 |
社会与环境 | 364篇 |
灾害及防治 | 132篇 |
出版年
2023年 | 79篇 |
2022年 | 242篇 |
2021年 | 214篇 |
2020年 | 121篇 |
2019年 | 137篇 |
2018年 | 266篇 |
2017年 | 237篇 |
2016年 | 307篇 |
2015年 | 259篇 |
2014年 | 390篇 |
2013年 | 705篇 |
2012年 | 443篇 |
2011年 | 523篇 |
2010年 | 406篇 |
2009年 | 390篇 |
2008年 | 440篇 |
2007年 | 418篇 |
2006年 | 385篇 |
2005年 | 299篇 |
2004年 | 271篇 |
2003年 | 256篇 |
2002年 | 213篇 |
2001年 | 299篇 |
2000年 | 197篇 |
1999年 | 139篇 |
1998年 | 97篇 |
1997年 | 103篇 |
1996年 | 69篇 |
1995年 | 76篇 |
1994年 | 74篇 |
1993年 | 62篇 |
1992年 | 55篇 |
1991年 | 50篇 |
1990年 | 48篇 |
1989年 | 46篇 |
1988年 | 30篇 |
1987年 | 22篇 |
1986年 | 22篇 |
1985年 | 20篇 |
1984年 | 21篇 |
1983年 | 24篇 |
1982年 | 24篇 |
1981年 | 20篇 |
1980年 | 11篇 |
1979年 | 15篇 |
1978年 | 12篇 |
1975年 | 13篇 |
1973年 | 9篇 |
1972年 | 11篇 |
1966年 | 8篇 |
排序方式: 共有8670条查询结果,搜索用时 62 毫秒
141.
142.
Heckrath G Djurhuus J Quine TA Van Oost K Govers G Zhang Y 《Journal of environmental quality》2005,34(1):312-324
Tillage erosion had been identified as a major process of soil redistribution on sloping arable land. The objectives of our study were to investigate the extent of tillage erosion and its effect on soil quality and productivity under Danish conditions. Soil samples were collected to a 0.45-m depth on a regular grid from a 1.9-ha site and analyzed for 137Cs inventories, as a measure of soil redistribution, soil texture, soil organic carbon (SOC) contents, and phosphorus (P) contents. Grain yield was determined at the same sampling points. Substantial soil redistribution had occurred during the past decades, mainly due to tillage. Average tillage erosion rates of 2.7 kg m(-2) yr(-1) occurred on the shoulderslopes, while deposition amounted to 1.2 kg m(-2) yr(-1) on foot- and toeslopes. The pattern of soil redistribution could not be explained by water erosion. Soil organic carbon and P contents in soil profiles increased from the shoulder- toward the toeslopes. Tillage translocation rates were strongly correlated with SOC contents, A-horizon depth, and P contents. Thus, tillage erosion had led to truncated soils on shoulderslopes and deep, colluvial soils on the foot- and toeslopes, substantially affecting within-field variability of soil properties. We concluded that tillage erosion has important implications for SOC dynamics on hummocky land and increases the risk for nutrient losses by overland flow and leaching. Despite the occurrence of deep soils across the study area, evidence suggested that crop productivity was affected by tillage-induced soil redistribution. However, tillage erosion effects on crop yield were confounded by topography-yield relationships. 相似文献
143.
Chinese brake fern (Pteris vittata L.) is a hyperaccumulator of arsenic (As) that grows naturally on soils in the southern United States. It is reasonable to expect that mycorrhizal symbiosis may be involved in As uptake by this fern. This is because arbuscular mycorrhizal (AM) fungi have a well-documented role in increasing plant phosphorus (P) uptake, P and As have similar chemical properties, and ferns are known to be colonized by AM fungi. We conducted a factorial greenhouse experiment with three levels of As (0, 50, and 100 mg kg(-1)) and P (0, 25, and 50 mg kg(-1)) and with and without Chinese brake fern colonized by a community of AM fungi from an As-contaminated site. We found that the AM fungi not only tolerated As amendment, but their presence increased frond dry mass at the highest As application rate. Furthermore, the AM fungi increased As uptake across a range of P levels, while P uptake was generally increased only when there was no As amendment. These data indicate that AM fungi have an important role in arsenic accumulation by Chinese brake fern. Therefore, to effectively phytoremediate As-contaminated soils, the mycorrhizal status of ferns needs to be taken into account. 相似文献
144.
Jim CY 《Journal of environmental management》2005,74(2):161-172
Urban trees in Hong Kong exist in stressful and harsh habitat conditions due mainly to the exceptionally high-density development mode. This study focuses on the cream of the urban tree stock, the heritage trees, which were selected according to five sets of stringent criteria: species, dimension, structure, condition, location, and special considerations. The study area covers the main urban core of the city. The loss of trees in two periods, 1993-1998 and 1999-2003, was monitored, with the predisposing and direct causes of damages ascertained as far as possible. Of the 380 heritage specimens, 54 trees were lost in the survey period. The main predisposing causes were injuries sustained in roadwork and construction activities, both related to root damage and soil disturbance. The principal direct causes were recent gradual decline and abrupt demise due to typhoon breakage. Three pairs of contributing variables registered statistically significant associations (chi(2) test), namely predisposing cause versus direct cause, tree growth form versus direct cause, and survey period versus direct cause. Principal component analysis identified three factors that explained 70% of the variance, namely tree form, tree stature, and growth environment. The main reasons for the high mortality were explored. The possible applications of the findings to improve tree protection and management were discussed in relation to the overall planning for meritorious greenery and green space especially in compact cities. 相似文献
145.
146.
Hawrot-Paw Małgorzata Koniuszy Adam Mikiciuk Małgorzata Izwikow Monika Stawicki Tomasz Sędłak Paweł 《Environmental science and pollution research international》2017,24(17):15022-15030
Environmental Science and Pollution Research - The purpose of this research was evaluation of the effect of soil contamination with waste coming from biomass gasification on chosen indicators of... 相似文献
147.
Xu Li Zimeng Liu Qing Xu Zhongyi Jiang Guoliang Ma 《Environmental Modeling and Assessment》2017,22(3):243-255
In this paper, we construct a multi-stage coordinated programming model under tax system to control SO2 emission. The model is based on an explicitly formulated SO2 abatement cost function created under Chinese condition. Analysis of the effectiveness and impact on the economy of the model is carried out with consideration of game theory. By solving the model, theoretical results show that the volume-based multi-stage SO2 tax system has two properties: effectiveness and equal-rate. Based on these theoretical results, empirical study is also performed using Chinese historical data. Compared with yearly single-stage programming model, the tax rate generated by the coordinated multi-stage programming model is time-invariant and rather moderate in scale. The total abatement cost among planning years in our model is 21.03 % less than the actual number and 6.68 % less than that in the single-stage situation. The tax payment suggested by our model is 10.62 % less than by the single-stage model. In general, a coordinated multi-stage programming model helps reduce the overall costs of environmental protection while achieving the same emission control target with less burden added to the economy. 相似文献
148.
Chen Yujun Guan Bin Wu Xingze Guo Jiangfeng Ma Zeren Zhang Jinhe Jiang Xing Bao Shibo Cao Yiyan Yin Chengdong Ai Di Chen Yuxuan Lin He Huang Zhen 《Environmental science and pollution research international》2023,30(5):11246-11271
Environmental Science and Pollution Research - In recent years, with global climate change, the utilization of carbon dioxide as a resource has become an important goal of human society to achieve... 相似文献
149.
Rose Emília Queiroz José Guerreiro Maria Anunciação Ventura 《Environment, Development and Sustainability》2014,16(5):1119-1135
In general, tourism plays a significant role in the economy of archipelagos and islands. The Autonomous Region of the Azores has a great potential for tourism, offering multiple attractions, both natural and cultural, creating a big challenge for a sustainable tourism policy since little attention has been paid to the archipelagos and their special needs. This work aims to understand the profile and type of ecotourist that visits the Azores. This knowledge is of great importance for a better management and development of nature-based tourism, and products tailored to the needs and expectations of visitors. The data were collected by means of exit surveys conducted at the Airport of São Miguel Island, the larger and most populated island of the archipelago, during the high tourist season—July–September 2009. The analysis of the visitor’s profile and preferences is crucial to draw adequate strategies of management for tourism, while it helps to adequate the offer to the demand. Results showed that 41.1 % of the tourists claimed to be attracted to the islands due to their “natural values” (e.g., landscape, biodiversity, and geodiversity). The most practiced activities were whale-watching (32.4 %) and mountaineering/hiking (31.6 %), followed by diving (7 %) and other sports (5.1 %). The tourists’ profile points to a mainstream, soft, and incidental type of ecotourist. This information helps to develop and support a strategic planning and management, both at local and regional levels, for sustainable tourism policies. 相似文献
150.
Ma Xiaodong Xue Yongxuan 《Environmental science and pollution research international》2023,30(13):35588-35601
Environmental Science and Pollution Research - More and more emphasis is placed on the common development of economy and ecological environment in China’s development strategy, and one of the... 相似文献