全文获取类型
收费全文 | 2614篇 |
免费 | 252篇 |
国内免费 | 265篇 |
专业分类
安全科学 | 405篇 |
废物处理 | 111篇 |
环保管理 | 655篇 |
综合类 | 1126篇 |
基础理论 | 234篇 |
环境理论 | 19篇 |
污染及防治 | 118篇 |
评价与监测 | 27篇 |
社会与环境 | 363篇 |
灾害及防治 | 73篇 |
出版年
2024年 | 9篇 |
2023年 | 50篇 |
2022年 | 66篇 |
2021年 | 80篇 |
2020年 | 109篇 |
2019年 | 104篇 |
2018年 | 102篇 |
2017年 | 163篇 |
2016年 | 183篇 |
2015年 | 137篇 |
2014年 | 110篇 |
2013年 | 277篇 |
2012年 | 222篇 |
2011年 | 268篇 |
2010年 | 178篇 |
2009年 | 145篇 |
2008年 | 100篇 |
2007年 | 142篇 |
2006年 | 110篇 |
2005年 | 92篇 |
2004年 | 64篇 |
2003年 | 66篇 |
2002年 | 52篇 |
2001年 | 53篇 |
2000年 | 46篇 |
1999年 | 40篇 |
1998年 | 19篇 |
1997年 | 20篇 |
1996年 | 16篇 |
1995年 | 12篇 |
1994年 | 21篇 |
1993年 | 7篇 |
1992年 | 8篇 |
1991年 | 7篇 |
1990年 | 8篇 |
1989年 | 2篇 |
1985年 | 2篇 |
1984年 | 4篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1980年 | 4篇 |
1979年 | 8篇 |
1978年 | 5篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有3131条查询结果,搜索用时 15 毫秒
991.
在环境经济系统中,能源是经济活动的驱动要素,是经济活动的自然基础。本研究以河南区域的资源经济关系为研究对象,选取改革开放以来,河南省1978年-2010年样本区间内国内生产总值和能源生产总量和消耗总量数据,运用协整检验、Granger因果关系检验和误差修正等计量经济统计模型,研究河南省的国内生产总值和能耗生产总量与能源消耗总量在时序维度的长期均衡和短期动态性关系,揭示河南省经济增长与能源生产和能源消费存在的关系,探寻能源与经济的作用关系。通过实证分析表明,在河南省经济增长过程中,能源生产与能源消费和国内生产总值存在着长期的动态均衡关系,Granger因果检验表明能源生产总量、能源消费总量是国内生产总值的Granger原因,能源消费总量是能源生产总量的Granger原因。以上研究结果表明,河南省的经济增长与能源供给的长期依赖关系依然存在。 相似文献
992.
采用0~0.5 mmol·L~(-1)蒽醌-2-磺酸钠(AQS)研究其对Klebsiella oxytoca GS-4-08厌氧降解甲基橙(MO)的影响,对比细菌产氢、降解碳源及生成产物等情况,得出最佳浓度为0.1 mmol·L~(-1).在该浓度下,Klebsiella oxytoca GS-4-08可在10 h内完全脱色MO,25 h内降解蔗糖达到92%,同时产生0.117 mol·mol~(-1)乙醇和0.116 mol·mol~(-1)乙酸,2.25 mol·mol~(-1)氢气;将实验结果与已有研究进行对比,分析了AQS促进Klebsiella oxytoca GS-4-08厌氧脱色MO与产氢的机制.通过将细菌降解过程中的物质转换为COD进行对比,对降解过程中电子转移进行了分析,得到0.1 mmol·L~(-1)AQS浓度时电子得率最高,其为87.98%;并将细菌降解过程中的能源转换进行对比,得到0.1 mmol·L~(-1)AQS浓度时能源产量最高,其为802 k J·mol~(-1);同时得出Klebsiella oxytoca GS-4-08发酵过程可产生两种以上生物燃料,表明了其在工业生产应用上的前景. 相似文献
993.
Climate change is one of the focuses to mitigate greenhouse effect and reduce carbon dioxide emissions.First,the paper summarizes on the carbon dioxide emission factors and methods suitable to the situation in China.Second,it analyzes the primary energy-related carbon dioxide emissions during the period between 1995 and 2005 from different fossil fuels and different zones.The trend of primary energy-related carbon dioxide emissions from 1995 to 2005 is"first decreasing and later increasing."Seven regions-Liaoning,Shanxi,Hebei,Shandong,Henan,and Jiangsu-and most of the provinces(cities or regions)were found to have similar trends regarding total carbon dioxide emissions in China.The annual carbon dioxide emissions and the growth ratio of these seven regions are much higher compared to those of the other 24 provinces(cities or regions).Finally,this paper puts forward some suggestions to reduce carbon dioxide. 相似文献
994.
Pollutant emissions,energy consumption and economic development in China:Evidence from dynamic panel data 总被引:1,自引:0,他引:1
This study investigates the relationship among pollutant emissions,energy consumption and economic development in China during the period 1982-2007 by using a one-step GMM-system model under a multivariable panel VAR framework,controlling for capital stock and labor force.Regarding the data for all 28 provinces as a whole,we find that there is a unidirectional positive relationship running from pollutant emission to economic development and a unidirectional negative relationship between pollutant emission and energy consumption.Based on traditional economic planning,the panel data of28 provinces are divided into two cross-province groups.It is discovered that in the eastern coastal region of China,there is only a unidirectional positive causal relationship leading from economic development to pollutant emission;while in the central and western regions,there are the unidirectional Granger causal relationships between pollutant emission and energy consumption,as well as between pollutant emission and economic development.There is also a unique unidirectional causal relationship running from economic development to energy consumption,which does not appear in the eastem coastal region or in China as a whole. 相似文献
995.
Wang Junsong 《中国人口.资源与环境(英文版)》2013,11(2):44-49
Abstract China has witnessed rapid economic development since 1978, and during the time, energy production and consumption developed at a tremendous speed as well. Energy efficiency which can be measured by energy consumption per unit of GDP, however, experienced continuous decrease. Theoretically, the change of energy efficiency can be attributed to industry structural change and technological change. In order to explain the transformation of Chinese energy efficiency, we adopt logarithmic mean Divisia index techniques to decompose changes in energy intensity in the period of 1994–2005. We find that technological change is the dominant contributor in the decline of energy intensity, but the contribution has declined since 2001. The change in industry structure has decreased the energy intensity before 1998, but raised the intensity after 1998. Decomposed technological effects for all sectors indicate that technological progresses in high energy consuming industries such as raw chemical materials and chemical products, smelting and pressing of ferrous metals, manufacture of non-metallic mineral products and household contribute are the principal drivers of China’s declining energy intensity. 相似文献
996.
Abstract Since the reform and opening up, China’s export trade has maintained a rapid growth; meanwhile, China’s energy consumption has been increasing sharply. “High export and high energy consumption” has become the feature of China’s trade and economic development. In this paper, based on the input–output analysis approach, the authors have conducted an empirical study on the export trade and energy consumption of 21 trade industrial sectors. The results show that, China is a big net exporter of embodied energy. Assuming that the export growth rate of embodied energy maintains to be about 23.6%, the average annual growth rate of the past 32 years, and based on the input–output data of 2005, by 2030 China’s net export of embodied energy would be over eight times more than the aggregate energy production, which is obviously infeasible. As a country of very low per capita energy, China must change its export pattern, encourage or restrain the export of different industrial sectors according to their energy consumption intensity, and promote structural change of energy– efficient exported products, so as to achieve the sustainable development. Accordingly, the authors put forward some suggestions. 相似文献
997.
The temperature is 56.5°C when acetone gas is rectified during the production of powdery phospholipid. If heat exchanger is added, heat energy that is reclaimed can be used by other heaters. On the basis of exchange hot water (51°C) 4m3 every minute, a factory with the productivity of powdery phospholipid being 10 ton a day can save 533.2 ton standard coal which is equivalent to 746.48 ton common coal. If this technique of saving energy and reducing emission could be widely used in correlative industries of all over the country, economic benefits will be prominent. 相似文献
998.
Abstract In recent years, scientists have been increasingly interested in the energy embodied in traded goods among countries. In this article, the direct energy intensities in various economic sectors of China were calculated with the data of energy consumption and output value of each sector, and the input–output table was used to estimate the external energy consumption. The total energy intensity of all sectors was then obtained. From the data of international trade, the energy embodied in goods trade of China was estimated for the period of 1994–2001. During this period, the average energy intensity of imported goods was always higher than that of exported ones. As a country with a surplus in international goods trade, China actually imported net embodied energy in the past few years. The net embodied energy imported was at the same magnitude of the imported energy in the form of fossil fuels. 相似文献
999.
Guangyu Qiao 《中国人口.资源与环境(英文版)》2013,11(3):233-238
Inspired by the green revolution, new energy vehicles (NEVs) provide a fresh, alternative mode of transportation for Chinese consumers that reduce their reliance on traditional, gasoline/diesel-based cars. However, despite strong government support for NEVs in China, the level of uptake by consumers remains slow. Using Shanghai as a case study, this article provides a much-needed insight into local consumers’ motivations to invest in NEVs through a survey of 100 Shanghai residents. Results indicate that current NEV promotion policies do not have a significant impact on the cognitive trade-off of NEV consumption under the “Integrated Consumer Behavior Model,” mainly due to inconvenient charging facilities, technical concerns regarding battery, higher prices, and wait-and-see attitudes regarding the pilot policy environment. Drawing on experiences from Sweden and New Zealand, this research serves to enhance knowledge on consumer attitudes towards NEVs and assist policy makers in developing more effective green consumption promotion campaigns in the future. 相似文献
1000.
《Environmental Communication: A Journal of Nature and Culture》2013,7(8):1041-1052
ABSTRACTThe Block Island Wind Farm (BIWF) is the first offshore wind farm in the United States. Using gatekeeping theory as a framework, this research analyzes local and regional/national newspaper coverage of the BIWF paying particular attention to the use of sources. The data suggest that the differences between newspaper source usage from 1 January 2008 to 1 July 2017 is minimal. However, business sources appeared more than any other group, including government sources, which is a new finding. The prevalence of business sources leads to important questions about the role of businesses in shaping narratives about community transitions to renewable energy systems. 相似文献