全文获取类型
收费全文 | 2968篇 |
免费 | 47篇 |
国内免费 | 97篇 |
专业分类
安全科学 | 151篇 |
废物处理 | 238篇 |
环保管理 | 509篇 |
综合类 | 344篇 |
基础理论 | 570篇 |
环境理论 | 4篇 |
污染及防治 | 932篇 |
评价与监测 | 248篇 |
社会与环境 | 96篇 |
灾害及防治 | 20篇 |
出版年
2023年 | 18篇 |
2022年 | 36篇 |
2021年 | 46篇 |
2020年 | 18篇 |
2019年 | 52篇 |
2018年 | 85篇 |
2017年 | 85篇 |
2016年 | 104篇 |
2015年 | 73篇 |
2014年 | 97篇 |
2013年 | 241篇 |
2012年 | 159篇 |
2011年 | 187篇 |
2010年 | 130篇 |
2009年 | 172篇 |
2008年 | 174篇 |
2007年 | 181篇 |
2006年 | 174篇 |
2005年 | 147篇 |
2004年 | 134篇 |
2003年 | 121篇 |
2002年 | 121篇 |
2001年 | 75篇 |
2000年 | 45篇 |
1999年 | 38篇 |
1998年 | 32篇 |
1997年 | 31篇 |
1996年 | 25篇 |
1995年 | 26篇 |
1994年 | 30篇 |
1993年 | 27篇 |
1992年 | 15篇 |
1991年 | 22篇 |
1990年 | 17篇 |
1989年 | 10篇 |
1988年 | 16篇 |
1986年 | 7篇 |
1985年 | 13篇 |
1984年 | 9篇 |
1983年 | 8篇 |
1982年 | 13篇 |
1981年 | 13篇 |
1980年 | 13篇 |
1979年 | 7篇 |
1978年 | 7篇 |
1977年 | 6篇 |
1976年 | 7篇 |
1972年 | 6篇 |
1971年 | 6篇 |
1969年 | 5篇 |
排序方式: 共有3112条查询结果,搜索用时 31 毫秒
61.
Ni-Bin Chang Y. Jeffrey Yang James A. Goodrich Ammarin Daranpob 《Journal of environmental management》2010,91(6):1397-1413
Global climate change will influence environmental conditions including temperature, surface radiation, soil moisture, and sea level, and it will also significantly impact regional-scale hydrologic processes such as evapotranspiration (ET), precipitation, runoff, and snowmelt. The quantity and quality of water available for drinking and other domestic usage is also likely to be affected by changes in these processes. Consequently, it is necessary to assess and reflect upon the challenges ahead for water infrastructure and the general public in metropolitan regions. One approach to the problem is to use index-based assessment, forecasting and planning. The drought indices previously developed were not developed for domestic water supplies, and thus are insufficient for the purpose of such an assessment. This paper aims to propose and develop a “Metropolitan Water Availability Index (MWAI)” to assess the status of both the quantity and quality of available potable water sources diverted from the hydrologic cycle in a metropolitan region. In this approach, the accessible water may be expressed as volume per month or week (i.e., m3/month or m3/week) relative to a prescribed historical record, and such a trend analysis may result in final MWAI values ranging from ?1 to +1 for regional water management decision making. The MWAI computation uses data and information from both historical point measurements and spatial remote-sensing based monitoring. Variables such as precipitation, river discharge, and water quality changes at drinking water plant intakes at specific locations are past “point” measurements in MWAI calculations. On the other hand, remote sensing provides information on both spatial and temporal distributions of key variables. Examples of remote-sensing images and sensor network technologies are in-situ sensor networks, ground-based radar, air-borne aircraft, and even space-borne satellites. A case study in Tampa Bay, Florida is described to demonstrate the short-term assessment of the MWAI concept at a practical level. It is anticipated that such a forecasting methodology may be extended for middle-term and long-term water supply assessment. 相似文献
62.
Chien-Song Chyang Yun-Long Han Li-Wei Wu Hou-Peng Wan Hom-Ti Lee Ying-Hsi Chang 《Waste management (New York, N.Y.)》2010,30(7):1334-1340
Pollutant emissions from co-firing of refuse derived fuel (RDF) and coal were investigated in a vortexing fluidized bed combustor (VFBC). RDF-5 was made of common municipal solid waste (MSW). CaCO3 was injected in the combustor to absorb HCl at 850 °C. The results show that NOx and HCl emissions increase with RDF-5 co-firing ratio. The NOx concentration in flue gas at the bottom of the combustor is higher than that at the top. However, the trend of HCl released is reverse compared with NOx emissions. It was found that the HCl concentration decreases with increasing the molar ratio of Ca/Cl. However, the effect of CaCO3 addition on HCl retention is not significant when the molar ratio of Ca/Cl is higher than 5. The chlorine content in fly ash increases obviously with the molar ratio of Ca/Cl. PCDD/Fs emissions decrease slightly with an addition of CaCO3. In this study incomplete combustion is regarded as the main cause for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) formation. 相似文献
63.
Rebecca Epanchin-Niell Jeffrey Englin Darek Nalle 《Journal of environmental management》2009,90(2):370-379
In large areas of the arid western United States, much of which are federally managed, fire frequencies and associated management costs are escalating as flammable, invasive cheatgrass (Bromus tectorum) increases its stronghold. Cheatgrass invasion and the subsequent increase in fire frequency result in the loss of native vegetation, less predictable forage availability for livestock and wildlife, and increased costs and risk associated with firefighting. Revegetation following fire on land that is partially invaded by cheatgrass can reduce both the dominance of cheatgrass and its associated high fire rate. Thus restoration can be viewed as an investment in fire-prevention and, if native seed is used, an investment in maintaining native vegetation on the landscape. Here we develop and employ a Markov model of vegetation dynamics for the sagebrush steppe ecosystem to predict vegetation change and management costs under different intensities and types of post-fire revegetation. We use the results to estimate the minimum total cost curves for maintaining native vegetation on the landscape and for preventing cheatgrass dominance. Our results show that across a variety of model parameter possibilities, increased investment in post-fire revegetation reduces long-term fire management costs by more than enough to offset the costs of revegetation. These results support that a policy of intensive post-fire revegetation will reduce long-term management costs for this ecosystem, in addition to providing environmental benefits. This information may help justify costs associated with revegetation and raise the priority of restoration in federal land budgets. 相似文献
64.
Jeong Kyungjun Hong Jiyeon Lee Yongjin Yang Jiyeon Lim Youngwook Shin Dongchun Kim Changsoo 《Environmental science and pollution research international》2021,28(28):37506-37519
Environmental Science and Pollution Research - Preschool children aged 3–6 years are vulnerable to exposed to particulate matter (“PM10” and “PM2.5”). It is required... 相似文献
65.
Shahi Nirmal Kumar Maeng Minsoo Kim Donghyun Lee Taehoon Dockko Seok 《Environmental science and pollution research international》2021,28(30):40598-40607
Environmental Science and Pollution Research - Dissolved air flotation (DAF) is a widely used treatment process in drinking water and wastewater treatment plants despite high energy cost associated... 相似文献
66.
Pizzol Damiano Foresta Carlo Garolla Andrea Demurtas Jacopo Trott Mike Bertoldo Alessandro Smith Lee 《Environmental science and pollution research international》2021,28(4):4095-4103
Environmental Science and Pollution Research - Male fertility and semen quality have declined over recent decades. Among other causes, exposure to environmental and occupational pollution has been... 相似文献
67.
Intaek Yoon YeonSang Lee Sohyun Kate Yoon 《Mitigation and Adaptation Strategies for Global Change》2017,22(6):863-878
As highlighted in the outcome of the Paris Agreement at the 21st Conference of Parties of the United Nations Framework Convention on Climate Change there has been a recent push for the stronger mitigation actions of cities, regions, and local governments. Energy efficiency is a tool that can be leveraged by not only industry or national governments but also cities, regions, and local governments for mitigation purposes. However, studies on energy efficiency as a mitigation tool thus far have focused on the national or transnational scale, and on certain sectors of industry. The purpose of this paper is to find the most cost-efficient energy efficiency measures (EEMs) at the city, region, and local government level. To that end, this paper examines the yearly energy savings and greenhouse gas (GHG) reduction intensity, as well as energy savings and GHG reduction efficiency, in the case of EEMs conducted by South Korean local governments. Yearly energy savings intensity and GHG reduction intensity are estimated to be in the range of 0.094~0.375 tonne of oil equivalent (TOE)/M-KRW (million Korean won) and 0.287~1.180 tCO2e/M-KRW. Results show that inverter installation at water and sewage treatment plants and improvement of pump efficiency are the most cost-efficient EEMs. Moreover, energy savings efficiency and GHG reduction efficiency are within the range of 18.29~45.31 %, at an average of 30.5 % GHG reduction potential. If this reduction potential is applied to the buildings and facilities regulated and run by cities/local governments, there is a worldwide reduction potential of 1.023 billion tCO2 compared to 2020 business as usual levels. 相似文献
68.
Formic acid was used for the nitrate reduction as a reductant in the presence of Pd:Cu/γ-alumina catalysts. The surface characteristics of the bimetallic catalyst synthesized by wet impregnation were investigated by SEM, TEM-EDS. The metals were not distributed homogeneously on the surface of catalyst, although the total contents of both metals in particles agreed well with the theoretical values. Formic acid decomposition on the catalyst surface, its influence on solution pH and nitrate removal efficacy was investigated. The best removal of nitrate (50 ppm) was obtained under the condition of 0.75 g/L catalyst with Pd:Cu ratio (4:1) and two fold excess of formic acid. Formic acid decay patterns resembled those of nitrate removal, showing a linear relationship between kf (formic acid decay) and k (nitrate removal). Negligible amount of ammonia was detected, and no nitrite was detected, possibly due to buffering effect of bicarbonate that is in situ produced by the decomposition of formic acid, and due to the sustained release of H2 gas. 相似文献
69.
A comprehensive review of climate adaptation in the United States: more than before, but less than needed 总被引:2,自引:0,他引:2
Rosina Bierbaum Joel B. Smith Arthur Lee Maria Blair Lynne Carter F. Stuart Chapin III Paul Fleming Susan Ruffo Missy Stults Shannon McNeeley Emily Wasley Laura Verduzco 《Mitigation and Adaptation Strategies for Global Change》2013,18(3):361-406
We reviewed existing and planned adaptation activities of federal, tribal, state, and local governments and the private sector in the United States (U.S.) to understand what types of adaptation activities are underway across different sectors and scales throughout the country. Primary sources of review included material officially submitted for consideration in the upcoming 2013 U.S. National Climate Assessment and supplemental peer-reviewed and grey literature. Although substantial adaptation planning is occurring in various sectors, levels of government, and the private sector, few measures have been implemented and even fewer have been evaluated. Most adaptation actions to date appear to be incremental changes, not the transformational changes that may be needed in certain cases to adapt to significant changes in climate. While there appear to be no one-size-fits-all adaptations, there are similarities in approaches across scales and sectors, including mainstreaming climate considerations into existing policies and plans, and pursuing no- and low-regrets strategies. Despite the positive momentum in recent years, barriers to implementation still impede action in all sectors and across scales. The most significant barriers include lack of funding, policy and institutional constraints, and difficulty in anticipating climate change given the current state of information on change. However, the practice of adaptation can advance through learning by doing, stakeholder engagements (including “listening sessions”), and sharing of best practices. Efforts to advance adaptation across the U.S. and globally will necessitate the reduction or elimination of barriers, the enhancement of information and best practice sharing mechanisms, and the creation of comprehensive adaptation evaluation metrics. 相似文献
70.
Jingzhou Zhao Hang Li Hongseok Choi Wayne Cai Jeffrey A. Abell Xiaochun Li 《Journal of Manufacturing Processes》2013,15(1):136-140
Real-time monitoring and control of temperature in ultrasonic joining of battery tabs and coupons are important for the quality improvement and cost reduction of battery assembly. However, there have always been difficulties in accurate and real-time measurement of temperature by conventional sensors for practical implementation. In this study, an innovative method is developed to provide an enabling technology for the in situ transient temperature monitoring, which could provide reliable feedback signals for potential control of ultrasonic joining processes. Micro thin film thermocouples (TFTCs) were fabricated on thin silicon substrates, which were then inserted in the welding anvil as a permanent feature so that the sensors were always located about 100 μm directly under the welding spot during joining of multilayer Ni-coated Cu thin sheets for battery assembly. Good repeatability was demonstrated while a temperature rise of up to 650 °C was obtained due to the closeness of the sensors to the welding spot. The inserts with thin film sensors remained functional after welding experiments. This method has a great potential for in situ transient temperature monitoring, and thus the control of ultrasonic joining processes to realize a practical smart joining system. 相似文献