首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   3557篇
  免费   532篇
  国内免费   2016篇
安全科学   145篇
废物处理   207篇
环保管理   399篇
综合类   3506篇
基础理论   634篇
环境理论   4篇
污染及防治   700篇
评价与监测   131篇
社会与环境   371篇
灾害及防治   8篇
  2024年   34篇
  2023年   166篇
  2022年   254篇
  2021年   224篇
  2020年   193篇
  2019年   221篇
  2018年   229篇
  2017年   250篇
  2016年   295篇
  2015年   327篇
  2014年   314篇
  2013年   506篇
  2012年   519篇
  2011年   498篇
  2010年   308篇
  2009年   260篇
  2008年   203篇
  2007年   234篇
  2006年   249篇
  2005年   139篇
  2004年   103篇
  2003年   100篇
  2002年   78篇
  2001年   69篇
  2000年   66篇
  1999年   52篇
  1998年   43篇
  1997年   33篇
  1996年   36篇
  1995年   18篇
  1994年   27篇
  1993年   20篇
  1992年   16篇
  1991年   8篇
  1990年   4篇
  1989年   3篇
  1987年   1篇
  1982年   1篇
  1981年   1篇
  1979年   1篇
  1973年   1篇
  1972年   1篇
排序方式: 共有6105条查询结果,搜索用时 109 毫秒
151.
Municipal solid waste landfills pose a threat on environment and human health, especially old landfills which lack facilities for collection and treatment of landfill gas and leachate. Consequently, missing information about emission flows prevent site-specific environmental risk assessments. To overcome this gap, the combination of waste sampling and analysis with statistical modeling is one option for estimating present and future emission potentials. Optimizing the tradeoff between investigation costs and reliable results requires knowledge about both: the number of samples to be taken and variables to be analyzed.This article aims to identify the optimized number of waste samples and variables in order to predict a larger set of variables. Therefore, we introduce a multivariate linear regression model and tested the applicability by usage of two case studies. Landfill A was used to set up and calibrate the model based on 50 waste samples and twelve variables. The calibrated model was applied to Landfill B including 36 waste samples and twelve variables with four predictor variables.The case study results are twofold: first, the reliable and accurate prediction of the twelve variables can be achieved with the knowledge of four predictor variables (Loi, EC, pH and Cl). For the second Landfill B, only ten full measurements would be needed for a reliable prediction of most response variables. The four predictor variables would exhibit comparably low analytical costs in comparison to the full set of measurements. This cost reduction could be used to increase the number of samples yielding an improved understanding of the spatial waste heterogeneity in landfills.Concluding, the future application of the developed model potentially improves the reliability of predicted emission potentials. The model could become a standard screening tool for old landfills if its applicability and reliability would be tested in additional case studies.  相似文献   
152.
实现2030年碳排放达峰不仅是中国为应对全球气候变化向国际社会做出的郑重承诺,也是中国未来经济结构转型与可持续发展的必然选择。基于中国实现2030年碳排放达到峰值的宏观目标为背景,本文以中国碳排放的主要行业工业为研究对象,首先运用拓展的STIRPAT模型对工业及其9个细分行业的碳排放达峰进行了情景预测,然后基于公平和效率的双重视角对工业细分行业的减排潜力进行评估。研究表明:(1)仅有低碳情景和抑制排放情景2可以实现中国碳排放2030年达峰,低碳情景是实现中国工业碳排放达峰的最佳发展模式,达峰时间最早(2030年),峰值最低(140.43亿t)。激进排放情景则是最差的发展模式,达峰时间最晚(2036年),峰值也最高(150.09亿t)。(2)工业内部各细分行业碳排放的最优达峰情景差别较大。建材和纺织制造业能够实现提前达峰,可以在这类行业率先实施达峰管理措施,使其带动其他行业陆续达峰。(3)最具减排潜力的行业是石油制造业,其次是电力行业,这些减排潜力较大的行业应该成为国家节能减排的重点对象。(4)基于工业各细分行业在减排公平性和效率性上的差异将工业9个细分行业分为四类。其中,石油、钢铁制造业和电力行业属于"高效高公平行业";化工、建材制造业属于"低效高公平行业";采掘业属于"高效不公平行业";纺织、轻工和机电制造业属于"低效不公平行业"。中国应针对不同类型的行业制定出相应的减排战略,将减排重点放在各行业最具潜力的方面。最后,文章对实现中国工业碳排放达峰管理提出了几点政策建议。  相似文献   
153.
本文运用IPCC的二氧化碳排放量测算方法,在省际层面测度了我国家庭部门直接能源消费碳排放,并基于扩展的STIRPAT和Kaya模型,构建家庭部门直接能源消费碳排放影响因子动态面板数据模型,对我国2003-2012年分省面板数据样本及城乡子样本进行系统GMM估计。本文研究表明,第一,我国城乡家庭部门碳排放总量和人均碳排放在近十年都呈快速上升趋势,家庭部门碳排放的空间分布具有明显的地域差异特征,高碳排放地区主要集中在东、中部地区,西部地区的碳排放水平较低;第二,城乡家庭部门生活能源消费的上期碳排放量对本期碳排放产生重要的正向影响,这反映出我国家庭部门碳排放具有显著的惯性特征和路径依赖性,是一种动态自适应机制;人口规模、居民消费水平、能源消费结构、碳排放强度、能源消费强度和城镇化因素,都对我国居民能源消费碳排放总量及人均碳排放具有显著的影响,城乡之间的家庭能源消费碳排放驱动因素存在差异。本文研究得到如下启示及政策含义:家庭部门碳减排将是一个有步骤、分区域的渐进过程,我国碳减排政策应当兼顾消费升级和碳排放的双重目标,努力构建分层次碳减排的适应性预期机制。具体而言,一方面应着眼于引导和激励居民低碳消费,缓解人口规模增加、消费水平提升和城镇化对家庭部门碳减排的压力;另一方面要通过能源价格改革、财政政策和环境规制政策等优化我国能源消费结构,不断降低煤炭消费比重,提高清洁能源的消费。同时,通过技术创新、设备改造等科技手段提高煤炭利用效率,降低碳排放强度,这些政策将更有利于城镇家庭部门碳减排。  相似文献   
154.
工业是碳排放的主要部门,科学识别工业CO_2排放的行业间传导并揭示其联动结构对于跨行业协同减排具有重要的理论和现实意义。本文基于1991-2012年中国工业36个两位数行业数据,在VAR模型框架下,利用Granger因果检验方法对CO_2排放的行业间传导关系进行了识别,并从关系视角出发,借助社会网络分析方法(SNA)揭示工业CO_2排放行业间传导的整体和个体网络结构特征,研究发现:工业CO_2排放的行业间传导呈网络结构形态,网络密度在1-6期的滞后阶数下呈先升高后下降的趋势,并且在滞后2期达到最高;燃气生产和供应业、电力热力生产和供应业、服装业、造纸及纸制品业、木材加工业具有较高的度数中心度、中介中心度、接近中心度,在网络中处于核心位置,并发挥中介和桥梁作用;在CO_2排放的行业传导网络中,煤炭采选业、黑色金属矿采选业、有色金属矿采选业等10个行业属于经纪人板块,医药制造业、饮料制造业、化学纤维制造业等9个行业属于净受益板块,金属制品业、塑料制品业、农副食品加工业等11个行业属于双向溢出板块,烟草加工业、石油加工及炼焦业、燃气生产和供应业等6个行业属于净溢出板块。基于上述结论,本文提出了工业CO_2排放的跨行业协同减排思路。  相似文献   
155.
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   
156.
用能权是具有公私法双重属性的管制性财产权。用能权交易是我国推进绿色发展的一项制度创新,对实现能耗总量和强度"双控"目标具有重要意义。用能权交易制度旨在从供给侧实现节能降耗目标,与其并行的节能减排市场化机制还包括节能量交易和碳排放权交易。节能量交易与用能权交易的规制对象、规制手段、制度设计目的和约束功能相近,故两者存在制度重复建设问题。用能权交易和碳排放权交易的制度设计目的具有协同性、规制对象有交叉,但两者在用能权指标和碳排放配额初始分配、履约等方面存在制度衔接不畅问题。通过法学和制度经济学分析,对用能权交易、节能量交易和碳排放权交易的制度整合与重构提出了建议。中国应当取消目标节能量交易制度,并以核定用能权交易取代项目节能量交易。用能权交易和碳排放权交易的制度衔接层面,应当打通用能权交易体系和碳排放权交易体系,建立联合履约机制,即允许用能单位或排放单位在满足一定条件的情况下使用用能权指标、核定用能权、碳排放配额或核证减排量履约。用能权指标与碳排放配额在履约方面的衔接机制重点在于一级市场的对接。用能权的初始分配仅仅是为重点用能单位设定节能义务的过程,应当以公平为原则,并且采取免费分配的方式。相对于用能权交易制度,碳排放权交易制度则是为了控制排放单位对碳排放空间这一资源的过度利用。因此,在碳排放配额初始分配环节,政府应当通过有偿分配的方式以实现国家对碳排放空间这一稀缺资源的所有者权益。建立核定用能权和核证减排量的联合履约机制,既允许用能单位购买核证减排量抵消其超额耗能,也允许排放单位购买核定用能权以抵消其超额排放,并对抵消比例设定限制。  相似文献   
157.
采用溶胶-凝胶法制备了活性炭纤维负载TiO2催化剂(TiO2/ACF),并通过SEM和XRD等手段对TiO2/ACF进行了表征。以邻苯二甲酸二甲酯(DMP)为目标降解物,考察了催化材料的电催化活性。实验结果表明:在反应温度为25 ℃、初始DMP质量浓度为100.0 mg/L、电解质Na2SO4质量浓度为100 mg/L、电流密度为62.5 mA/cm2、电极板间距为4 cm的条件下,经过40 min的降解,DMP质量浓度为1.8 mg/L,DMP去除率为98.2%;TiO2/ACF在反应过程中可以原位再生,经6次重复使用后仍保持很高的催化活性,对DMP的去除率仍达90%以上。  相似文献   
158.
Matthew Daly 《Local Environment》2017,22(11):1358-1377
Many intentional communities worldwide, such as ecovillages and co-housing communities, have explicit goals of living in an environmentally sustainable manner, and are taking conscious steps towards these goals in response to the widely discussed unsustainability of the global sociotechnical system. There are numerous claims from researchers and community members, in the academic and grey literature, that intentional communities are making significant improvements towards sustainability goals, particularly in terms of environmental impact. However, actual measures of progress, with evidence supporting these claims, are relatively scarce. This paper presents the findings of a systematic review of quantitative studies of the environmental impact of intentional communities, including comparisons with relevant “mainstream” communities. The review focused on the two indicators that are most commonly reported in studies of the impact of intentional communities – the ecological footprint and the carbon footprint. This review was undertaken as there is a lack of literature reviews that comprehensively compile existing quantitative studies about intentional communities. In total, the review identified 16 separate studies covering 23 communities and 30 footprint measurements, with publication dates ranging from 2000 to 2014. This is a greater number of studies than in any other literature review of this topic. Taken as a whole, these compiled studies provide strong support for claims of greater environmental sustainability within these communities, and reinforce the need for greater research and exploration of the role sustainability-oriented intentional communities can play in the transition to more sustainable sociotechnical systems.  相似文献   
159.
The only joint effort area of provincial and municipal governments resides in Guangdong Province and Shenzhen City in China’s carbon emission trading system (ETS) pilots, which characterize the national carbon ETS plots. The present study on the operating experience from this area has important reference value for the national carbon ETS. Analysis and comparison of the key elements show many differences in coverage, total allowance, allowance allocation, and MRV mechanism between Guangdong and Shenzhen carbon ETS. The present study provides the following explanation: (1) the design characteristics of carbon ETS (e.g. coverage, total quotas, the allocation, and MRV mechanism) depend on the local geographical conditions and policy goals. The differences of economic structure in Guangdong Province and Shenzhen City result in different coverage, which then result in differences in other management elements. (2) The operating state of the carbon market is affected by overall design of carbon ETS: in the case of tighter total allowance, lower proportion of China Certified Emission Reductions, and harsher punishment, the carbon market is relatively active, which intends to produce carbon financial market. Based on deep analysis of operation characteristics of carbon ETS in Guangdong and Shenzhen, the present study suggests that (1) the allowance should be allocated freely at the beginning stage and then gradually transited to the voluntary paid auction; (2) the allowances assigned to companies shall be linked up with their energy-saving objectives; (3) the output fluctuations and economic influence on the allowance allocation should be properly handled to maintain the fairness and consistence of allowance allocation standards; (4) stable public expectation is one of the key elements to maintain the regular operation of carbon ETS; (5) constrained carbon emission behavior outside ETS can contribute to social justice; and (6) the improvement of professional skills of relevant personnel in the enterprise and independent third party can enhance carbon emissions data reliability.  相似文献   
160.
基于欧盟碳市场配额现货与期货的发展经验和对我国统一碳市场建设的借鉴,本文以2005-2012年欧盟碳排放权交易体系(EU ETS)欧盟配额的现货和期货价格为样本研究二者之间的关系。本文运用单位根检验(ADF检验)的方法验证现货与期货价格的序列平稳性,并在序列平稳的前提下基于协整理论研究现货价格与期货价格的长期均衡关系,反映了二者间的静态关系。但短期内这一静态关系并不成立,反而表现出一定的动态性,短期价格的变动能够真实地反映市场需求,对价格的形成起着重要作用,因而采用向量误差修正模型重点研究二者间的短期动态关系。研究表明:1碳现货价格与期货价格间有着不同程度的影响,二者存在长期均衡,但短期内受市场特定因素的影响,二者又有所偏离;2期货价格反应灵敏,偏离均衡后调整速度快于现货,而且期货的滞后期价格对现货价格影响显著,这更加突显了碳期货的价格发现作用;3期货市场涉及了投资者对市场的预期和判断,较现货交易包含了更多的投机性,价格更为灵活,波动频繁,增加了市场风险。最后,根据结论对我国碳市场建设提出一些启示和建议:针对现货与期货价格之间的动态关系,应当积极开发和利用碳期货市场,通过期货的价格发现功能形成合理碳价,同时需要增强期货市场与现货市场的透明度,实现信息的传递与分享,最终实现期货市场对现货市场的补充和完善;为规避期货价格的波动性所带来的风险,需要建立一套完善的风险防控体系,在风险可控的前提下利用期货价格对市场进行预期,及时引导市场价格,形成完善的价格机制,为全国统一碳市场建设提供价格基础。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号