全文获取类型
收费全文 | 1350篇 |
免费 | 138篇 |
国内免费 | 304篇 |
专业分类
安全科学 | 46篇 |
废物处理 | 50篇 |
环保管理 | 317篇 |
综合类 | 802篇 |
基础理论 | 127篇 |
环境理论 | 6篇 |
污染及防治 | 96篇 |
评价与监测 | 71篇 |
社会与环境 | 262篇 |
灾害及防治 | 15篇 |
出版年
2024年 | 13篇 |
2023年 | 68篇 |
2022年 | 70篇 |
2021年 | 82篇 |
2020年 | 69篇 |
2019年 | 54篇 |
2018年 | 62篇 |
2017年 | 87篇 |
2016年 | 107篇 |
2015年 | 101篇 |
2014年 | 81篇 |
2013年 | 142篇 |
2012年 | 112篇 |
2011年 | 156篇 |
2010年 | 50篇 |
2009年 | 58篇 |
2008年 | 46篇 |
2007年 | 54篇 |
2006年 | 46篇 |
2005年 | 47篇 |
2004年 | 33篇 |
2003年 | 35篇 |
2002年 | 44篇 |
2001年 | 38篇 |
2000年 | 44篇 |
1999年 | 17篇 |
1998年 | 15篇 |
1997年 | 12篇 |
1996年 | 12篇 |
1995年 | 11篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1991年 | 6篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1977年 | 3篇 |
1972年 | 3篇 |
排序方式: 共有1792条查询结果,搜索用时 31 毫秒
51.
Akira KONDO Esrom HAMONANGAN Satoshi SODA Akikazu KAGA Yoshio INOUE Masaharu EGUCHI Yuta YASAKA 《环境科学学报(英文版)》2007,19(6):709-713
Total suspended particulate mater (TSP) concentrations were monitored for one year from July 2000 and for one year from April 2003 in Jakarta City. Thirteen elemental TSP components, aluminum (Al), sodium (Na), iron (Fe), lead (Pb), potassium (K), zinc (Zn), titanium (Ti), manganese (Mn), bromine (Br), copper (Cu), chromium (Cr), nickel (Ni), and vanadium (V) were analyzed by a sequential X-ray fluorescence spectrometer. Al, Na, Fe, K, and Pb were major components at most of the sampling locations in 2000. However, only Pb in 2003 dramatically decreased to one tenth. The phase-out of leaded gasoline began on July 1, 2001 in Jakarta City and lead content in gasoline decreased to one tenth, too. The decrease in Pb concentration was a result of the phase-out of leaded gasoline, as lead emissions mainly are exhaust gas from vehicles. 相似文献
52.
贸易中的隐含碳流动对中国的二氧化碳排放具有重要影响。从现有的文献来看,尽管出现了大量的针对中国贸易中隐含碳的相关研究,但由于数据及方法的不同,结果之间存在较大差异,很大程度上影响了研究结果的科学性和应用价值。本文对现有的中国国际贸易隐含碳文献进行了比较研究,结果发现:不同研究得出了相对一致的结论,但在隐含碳的具体数量上差异巨大。定性来看,中国是一个隐含碳净出口国,净出口量呈现出逐年增加的趋势。定量来看,1997-2007年,中国隐含碳出口量从3.1-8.8亿t增长到17.2-30.2亿t二氧化碳;隐含碳进口量从1.0-7.0亿t增长到5.8-16.5亿t二氧化碳;隐含碳净出口量从1.8-7.3亿t增长到11.4-22.6亿t二氧化碳;隐含碳净出口量占国内总排放量的比重由5%-20%增长到17%-30%。贸易中隐含碳核算结果的不确定性主要来自三个方面:核算方法产生的不确定性、数据融合产生的不确定性以及原始数据引入的不确定性。总体来看,多区域投入产出模型的研究结果相对稳定,可重复性较高;从数据精度和数据可获得性方面考虑,40个左右的部门分类可以取得较为理想的结果:把中国划分为多个区域研究国际贸易中的隐含碳在理论上更加可靠。国家气候变化对外谈判和国内减排目标的实现都需要对碳排放进行精确管理。在未来的研究中,应重视隐含碳核算的不确定性研究,逐步提高隐含碳核算的精度,更好地服务于国家的气候变化政策。 相似文献
53.
Foreign trade drives China’s growth,but as the trade scale continues to expand,the carbon emissions also increase quickly.Based on the industry panel data from 1996 to 2010,this paper calculates carbon emissions of 27manufacturing industries.According to the intensity of carbon emissions,this paper divides the manufacturing sectors into low carbon and high carbon manufacturing industry and then analyzes the carbon emission trends.Next,the paper uses the feasible generalized least square regression to verify the existence of environmental Kuznets curve(EKC)of the manufacturing industry’s carbon.In order to investigate the carbon leakage problem,the regression also includes the interaction term between trade and industrial value added.Our findings are as follows:the carbon emissions of the whole manufacturing industry and low carbon manufacturing industry accord with the EKC curve,but have a linear relationship with the high carbon manufacturing industry;trade reduces the carbon emissions of the whole manufacturing industry and low carbon manufacturing industry,but it increases those of the high carbon manufacturing industry;for the whole manufacturing industry and low carbon manufacturing industry,there is no carbon leakage,but it exists in the high carbon manufacturing industry.On the whole,pollution haven hypothesis does not hold up in China,and China does not need to limit industry foreign trade to reduce the emission of CO2.But the manufacturing industry will still be the main engine of the economic growth,and therefore our country should make an effective low-carbon policy,introduce advanced technology,increase R&D investment into lowcarbon technologies,and upgrade and transform the original equipment to change the backward mode of production. 相似文献
54.
刘丽萍 《中国人口.资源与环境》2011,(Z1)
根据云南省能源消费量,计算了由能源消费产生的CO2排放量及单位GDP碳排放强度。结果表明:近10年来,随着社会经济的快速发展,云南省能源消费及能源消费导致的CO2排放总量也呈现出显著上升的趋势。云南的碳排放强度高于全国平均水平,但人均碳排放量低于全国平均水平。以工业为主的第二产业是能源消费及碳排放的主体,其碳排放占总量的75%。 相似文献
55.
基于2003~2014年长江经济带的省际面板数据探讨了不同类型的环境规制对国际RD溢出效应的影响,通过熵值法客观赋权,构建命令控制型、市场激励型和自愿参与型3种环境规制指数,进一步考察了不同类型的环境规制对国际RD溢出的影响。研究表明:(1)环境规制对国际RD溢出水平呈现"反N型"曲线关系,虽然类型不同,但随着环境规制强度不断提升,国际RD溢出效应均呈现先下降、后上升、再下降的趋势;(2)不同类型的环境规制对国际RD溢出的作用具有异质性,当前在长江经济带发挥作用的主要是命令控制型和市场激励型环境规制,自愿参与型环境规制对国际RD溢出效应的激励作用尚未完全显现。结论在一定程度上印证了"波特假说"在开放条件下也是成立的,最后依据上述结论提出了相应的政策建议。 相似文献
56.
Paul A.Steenhof 《中国人口.资源与环境(英文版)》2005,3(2)
1 INTRODUCTIONEnergy and environmental issues in China have receivedsignificant attention in both the peer-reviewed literatureand in international energy and environmental policymaking in the last number of years. China's coal dominatedenergy consumption results in significant regional pollutionproblems, most notably acid rain that affects nearly 1/3rdof China's landmass and air pollution that plagues manyof its major cities. China now ranks as the top emitterof sulphur dioxide (SO2) pol… 相似文献
57.
John Rice 《Journal of Environmental Planning and Management》2016,59(1):44-61
Recent climate change projections and a push towards a universal agreement on carbon emission reductions suggest that firms will need to respond to future regulatory changes. This paper employs an influencing strategies lens to examine how large-scale firms might respond to future climate change regulations. The study uses a structured qualitative methodology to explore and explicate the strategic responses from 21 international firms to the proposed emissions trading scheme outlined in Australia's Garnaut Climate Change Review. The results of the analysis show that firms can use pre-emptive influencing strategies in attempts to shape and mould regulatory design parameters, secure high levels of transitional economic support, and shift the balance of public policies and expenditure. Complementary defensive strategies may also target policy makers and regulators with some of the potential negative consequences of the new regulations. 相似文献
58.
Seyfi Polat Ahmet Uyumaz Emre Yilmaz Tolga Topgül H. Serdar Yücesu 《International Journal of Green Energy》2016,13(1):63-70
EGR is one of the most significant strategies for reducing especially nitrogen oxides (NOx) emissions from internal combustion engines. The thermal efficiency of spark ignition engines is lower than compression ignition engines because of its lower compression ratio. If the compression ratio is increased to obtain higher thermal efficiency, there may be a knocking tendency in spark ignition engines. EGR can be used in order to reduce NOx emissions and avoid knocking phenomena at higher compression ratios. In-cylinder temperature at the end of combustion is decreased and heat capacity of fresh charge is increased when EGR applied. Besides EGR, spark timing is another significant parameter for reducing exhaust emissions such as nitrogen oxides, and unburned hydrocarbon (UHC). In this study the effects of EGR and spark timing on spark ignition engine were investigated numerically. KIVA codes were used in order to model combustion process. The combustion process has been modeled for a single cylinder, four stroke and gasoline direct injection (GDI) spark ignition engine. The results showed that in-cylinder pressure and heat release rate decrease as EGR ratio increase. In-cylinder pressure increases with the advancing of spark timing. Advancing spark timing increases the heat release rate and in-cylinder temperature. The simulation results also showed that EGR reduced exhaust gas temperature and NOx emissions. 相似文献
59.
Zhenshu Wang Yunpeng Shi Xiaodi Wang Qi Zhang Shichao Qu 《International Journal of Green Energy》2016,13(12):1267-1280
The drying up of the fossil energy sources and the damage from unchecked carbon emissions demand the development of low carbon economy, which promotes the development of new energy sources, such as wind power and photovoltaic. However, the direct connections of wind/photovoltaic power into power grid bring great impacts on power systems, thus affecting the security and stability of power system operations, which challenges the power system dispatching. In despite of many methods for power system dispatch, lack of the models, for power system containing wind power and photovoltaic considering carbon trading and spare capacity variation (PSCWPCCTSCV), restricts the further optimal operations of power systems. This paper studies the economic dispatch modeling problem of power system containing wind power and photovoltaic, establishes the model of economic dispatch of PSCWPCCTSCV. On this basis, adaptive immune genetic algorithm is applied to conduct the economic operation optimization, which can provide the optimal carbon trading price and the optimal power distribution coefficient. Finally, simulations based on the newly proposed models are made to illustrate the economic dispatch of PSCWPCCTSCV. The results show that optimization with the proposed model can not only weaken the volatility of the new energy effectively, but also reduce carbon emissions and reduce power generation costs. 相似文献
60.
Giorgio Zamboni Silvia Marelli Giulio Marmorato Massimo Capobianco 《International Journal of Green Energy》2016,13(5):481-488
A cooperative fuel research (CFR) engine was modified and instrumented in order to control operating conditions and to measure engine parameters and in-cylinder pressure diagrams. Aiming at the comparison of different alternative fuels, an experimental procedure was defined, including cetane number (CN) evaluation and the definition of engine operating quantities in different working points, for fixed levels of compression ratio (CR) and injection advance. An investigation was made considering several blends of methyl-esters of rapeseed oil (RME) and of a mix of vegetable oils (VOME) with conventional diesel oil. The defined experimental procedure was applied to assess CN, engine brake thermal efficiency (bte) and exhaust emissions. Results show that the biodiesel content has a positive influence on soot emissions, with strong reduction, while thermal efficiency and NOX emissions are negatively affected, which can be justified taking into account fuel properties and changes in combustion process. As observed outcomes are generally in line with those presented in literature, the facility proved to be a suitable tool for basic investigations on alternative fuels to be used in specific applications. 相似文献