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   2383篇
  免费   120篇
  国内免费   300篇
安全科学   326篇
废物处理   131篇
环保管理   424篇
综合类   1299篇
基础理论   240篇
环境理论   2篇
污染及防治   181篇
评价与监测   34篇
社会与环境   138篇
灾害及防治   28篇
  2024年   4篇
  2023年   24篇
  2022年   31篇
  2021年   62篇
  2020年   51篇
  2019年   42篇
  2018年   54篇
  2017年   69篇
  2016年   71篇
  2015年   69篇
  2014年   109篇
  2013年   146篇
  2012年   135篇
  2011年   201篇
  2010年   136篇
  2009年   168篇
  2008年   101篇
  2007年   190篇
  2006年   180篇
  2005年   121篇
  2004年   122篇
  2003年   116篇
  2002年   94篇
  2001年   98篇
  2000年   91篇
  1999年   65篇
  1998年   46篇
  1997年   40篇
  1996年   28篇
  1995年   34篇
  1994年   26篇
  1993年   17篇
  1992年   9篇
  1991年   12篇
  1990年   4篇
  1989年   4篇
  1988年   4篇
  1987年   4篇
  1986年   3篇
  1985年   1篇
  1984年   4篇
  1983年   2篇
  1981年   3篇
  1980年   1篇
  1978年   4篇
  1977年   4篇
  1975年   1篇
  1972年   1篇
  1971年   1篇
排序方式: 共有2803条查询结果,搜索用时 437 毫秒
951.
目前中国高速公路建设没有相应的清洁生产标准,因而高速公路建设缺乏有效的管理。根据高速公路的建设特点和清洁生产的要求,从"全过程管理"、"污染预防"、"环境影响最小化"的角度构建高速公路清洁生产指标体系,同时对指标进行了初步分析,以期减少高速公路的建设对环境的影响,从而实现"两型社会"的目标。  相似文献   
952.
There is strong evidence that a meat and dairy-based diet is a very important contributor to climate change. However, the correlation between the production and consumption of livestock and anthropogenic climate change has received minimal media coverage. The literature for English-speaking countries shows a sort of media blind spot for meat in that the news media barely address, or do not address, the responsibility of individuals' dietary choices with regard to this issue. In this paper, we provide data for press coverage in Southern Europe from a sample of the top 10 Spanish and Italian newspapers for a seven-year period (2006–2013). Data from our samples correlate with findings from previous studies. However, our comparative study suggests that there are also meaningful differences between both countries studied while their alleged Mediterranean dietary background makes no difference in terms of ethical or dietary sensitivity.  相似文献   
953.
Abstract

The objective of this research is to design an approach for selecting appropriate solutions to efficiently and productively reduce environmental pollution and water, energy and raw material consumption in a recycled paper manufacturing facility, the paper mill in Latif, Iran. To reach this goal, we develop a decision-making model using the Analytic Hierarchy Process (AHP). The proposed model provides a framework for cleaner production implementation specific to the paper industry. Pairwise comparisons of the results of designed questionnaires resulted in the hierarchy model being divided into five major groups: production modification; process change; preventive maintenance; renewal; and manpower resources.These five groups include 31 sub-criteria and seven alternatives. The results showed that process change yields the highest priority among the main criteria and that industrial automation and its technology level gives the highest priority among sub-criteria. Regarding the alternatives, reduction of environmental pollution is the most important solution for cleaner production in the industry. Also, product modification is the most sensitive criterion affecting the alternatives priority.  相似文献   
954.
A great amount of energy is wasted in industry by machines that remain idle due to underutilisation. A way to avoid wasting energy and thus reducing the carbon print of an industrial plant is to consider minimisation of energy consumption objective while making scheduling decisions. To minimise energy consumption, the decision maker has to decide the timing and length of turn off/turn on operation (a setup) and also provide a sequence of jobs that minimises the scheduling objective, assuming that all jobs are not available at the same time. In this paper, a framework to solve a multiobjective optimisation problem that minimises total energy consumption and total tardiness is proposed. Since total tardiness problem with release dates is an NP‐hard problem, a new greedy randomised multiobjective adaptive search metaheuristic is utilised to obtain an approximate pareto front (i.e. an approximate set of non‐dominated solutions). Analytical Hierarchy Process is utilised to determine the ‘best’ alternative among the solutions on the pareto front. The proposed framework is illustrated in a case study. It is shown that a wide variety of dispersed solutions can be obtained via the proposed framework, and as total tardiness decreases, total energy consumption increases.  相似文献   
955.
Hydrogen is an indispensable energy carrier for the sustainable development of human society. Nevertheless, its storage, transportation, and in situ generation still face significant challenges. Methanol can be used as an intermediate carrier for hydrogen supplies, providing hydrogen energy through instant methanol conversion. In this study, a sorption-enhanced, chemical-looping, oxidative steam methanol-reforming (SECL-OSRM) process is proposed using CuO–MgO for the on-board hydrogen supply, which could be a promising method for safe and efficient hydrogen production. Aspen Plus software was used for feasibility verification and parameter optimization of the SECL-OSRM process. The effects of CuO/CH3OH, MgO/CH3OH, and H2O/CH3OH mole ratios and of temperature on H2 production rate, H utilization efficiency, CH3OH conversion, CO concentration, and system heat balance are discussed thoroughly. The results indicate that the system can be operated in auto-thermal conditions with high-purity hydrogen (99.50 vol%) and ultra-low-concentration CO (<50 ppm) generation, which confirms the pos-sibility of integrating low-temperature proton-exchange membrane fuel cells (LT-PEFMCs) with the SECL-OSRM process. The simulation results indicate that the CO can be modulated in a lower concentration by reducing the temperature and by improving the H2O/CH3OH and MgO/CH3OH mole ratios.  相似文献   
956.
基于彼得斯治理理论,分析了京津冀地区的协同发展现状和要求,重构了其协同发展路径。结果表明:①要素禀赋、区域政策分别是区域协同发展的客观基础和主观条件。②区域协调发展新机制为京津冀地区提出了“坚持以北京和天津尤其是以非首都功能疏解为引领,借助市场力量调动各个主体的积极性,同时注重协同方式(机制)建设”的新要求。③京津冀协同发展路径重构可从“由软硬兼施的市场(市场平台和政府效能)、三维协同的主体(地方政府,中央政府和非政府部门)和富有弹性的方式(临时机构和互动机制)”的“3M”策略入手。  相似文献   
957.
“十四五”时期,我国进入了以降碳为重点战略方向、推动减污降碳协同增效的发展阶段。推进工业园区清洁生产审核能有效提升园区清洁生产水平,对于促进工业领域绿色低碳转型具有重要意义。本研究首先回顾了我国工业园区的发展历程,梳理了我国工业园区的发展现状,提出工业园区发展面临的问题及开展清洁生产审核的必要性;其次,分别从政策、研究、实践层面详细论述了工业园区推进清洁生产审核的进展;再次,分析推进工业园区清洁生产审核存在的问题;最后,建议下一步从完善政策支撑体系、加强方法学研究、强化试点示范作用三个方面推进工业园区清洁生产审核。本研究将为我国推进工业园区清洁生产审核提供理论依据和政策支持。  相似文献   
958.
通过改变CSTR系统内pH值,启动发酵类型由乙醇型向丁酸型转化,研究了转化前后系统内产氢动态和细菌群落变迁.结果表明,在有机负荷不变的情况下,启动发酵类型转化15d后,系统内种群由乙醇型转化为丁酸型,消耗碱度量由350mg.L-1增至1720mg.L-1,平均比产氢速率由21.2mol.kg-.1d-1降低至11.1mol.kg-.1d-1.荧光原位杂交技术(FISH)对反应系统内3类微生物群的监测结果表明,未启动转化时,肠杆菌、梭菌Ⅰ、Ⅱ和梭菌Ⅺ的相对丰度分别为22%、48%和30%,转化结束后,3类细菌的相对丰度为19%、24%和55%.  相似文献   
959.
对新诺明对乙酰氨基苯磺酰氯岗位排放的有机废水用结析沉降法回收对氨基苯磺酸和硫酸 ,实行了在生产过程中控制减少污染物的排放。降低未端处理污染负荷使污水达标排放。  相似文献   
960.
英法炼油环保与清洁生产考察   总被引:3,自引:0,他引:3  
英、法两国政府制订了既严格又切实可行的环保法规和标准,鼓励企业推行清洁生产。追求更好的环保业绩已成为企业经营活动的重要组成部分。“低压湿式氧化”技术可在低温、低压的条件下处理高浓度的有机废水。  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