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941.
煤矿风井噪声控制的声学设计和阻力损失计算研究   总被引:1,自引:0,他引:1  
张弛 《环境工程》2005,23(2):52-55
煤矿风井空气流量大 ,噪声辐射强 ,正确合理的消声器声学设计和阻力损失计算是噪声控制成功的关键。  相似文献   
942.
废弃地的景观与生态恢复研究   总被引:16,自引:3,他引:13  
废弃地是一种对生态环境造成重大破坏并且造成土地资源浪费的土地类型,如何进行合理的改造以形成可持续的土地利用模式是十分棘手的问题.利用新乡市北站区世利生态园的废弃地改造项目进行了废弃地"变废为宝"的探索,对合理进行废弃地的景观与生态恢复进行了较为深入的研究.通过对该废弃地现状的分析,得出对其进行合理的景观与生态恢复迫在眉睫.依据景观设计与生态恢复的理论、方法与原则,提出了景观恢复与生态恢复的具体措施,该措施可满足废弃地在自然生态、景观、经济和社会发展等方面可持续发展的要求.   相似文献   
943.
针对粉煤灰排放产生二次污染问题,经过分析比较,选用了科学的加湿排放工作原理,设计了用于粉煤灰排放的新型灰料加湿卸灰机。  相似文献   
944.
李耀庄  唐义军 《火灾科学》2005,14(4):234-238
比较分析了五根混凝土连续梁在碳纤维布加固后的极限荷载、变形、裂缝、延性系数等指标.在实际加固工程中无法对钢筋混凝土连续梁梁项进行加固,因此在试验中采用CFRP来加固梁的跨中,增强其正截面的抗弯承载力,并利用梁支座处出现塑性铰,引起弯矩重分布的特性,来达到加固的目的.为使试验更加接近加固工程实际情况,试验中加固是在持载情况下进行的.试验研究表明:使用碳纤维布提高高温作用后的混凝土连续梁的方法,能有效地抵抗二次火灾的影响;基于试验结果,推导出高温作用后碳纤维布加固的实用设计方法,与试验数据可以较好地吻合.在不能找出加固后梁所有失效模式的情况下,利用分阶段平截面弹塑性分析法求出加固后连续梁的极限挠度,求出了梁的功能(挠度)可靠度.  相似文献   
945.
ABSTRACT: The environment surrounding urban streams imposes constraints upon stream enhancement projects. Constraints include bridges, culverts, highways, sewer and water lines, lack of easements, and other floodplain structures. The consequences of failure of these infrastructure constraints can be significant and should be considered in the design process. Fault tree analysis provides a systematic technique for analyzing the interactions of events that could lead to infrastructure failure. A case study of a stream in Pittsburgh, Pennsylvania, shows that fault tree analysis can effectively model the interactions between the stream system and the infrastructure constraints and predict the most likely modes of failure. In addition, the relative success of alternative designs and failure mitigation techniques can be assessed using this analysis tool, lending insight into the urban stream enhancement design process. The method could also provide justification in the design permitting process and input for risk assessment.  相似文献   
946.
ABSTRACT: The designs of stream channel naturalization, rehabilitation, and restoration projects are inherently fraught with uncertainty. Although a systematic approach to design can be described, the likelihood of success or failure of the design is unknown due to uncertainties within the design and implementation process. In this paper, a method for incorporating uncertainty in decision‐making during the design phase is presented that uses a decision analysis method known as Failure Modes and Effects Analysis (FMEA). The approach is applied to a channel rehabilitation project in north‐central Pennsylvania. FMEA considers risk in terms of the likelihood of a component failure, the consequences of failure, and the level of difficulty required to detect failure. Ratings developed as part of the FMEA can provide justification for decision making in determining design components that require particular attention to prevent failure of the project and the appropriate compensating actions to be taken.  相似文献   
947.
对大型多功能公共建筑的电气设计中的负荷分级、负荷计算、用电计量与电费计收、低压电气主接线形式等几个方面的问题进行了探讨  相似文献   
948.
结构防火在舰船防火设计中的应用   总被引:13,自引:0,他引:13  
王志国  殷沐德 《火灾科学》2001,10(2):113-115
从舰船火灾发生的规律和特点出发,本着“重点在于防”的精神,论述了舰船消防设计的原则和任务,以及舰船结构防火中必须考虑的几个问题。  相似文献   
949.
Ecological distance-based spatial capture–recapture models (SCR) are a promising approach for simultaneously estimating animal density and connectivity, both of which affect spatial population processes and ultimately species persistence. We explored how SCR models can be integrated into reserve-design frameworks that explicitly acknowledge both the spatial distribution of individuals and their space use resulting from landscape structure. We formulated the design of wildlife reserves as a budget-constrained optimization problem and conducted a simulation to explore 3 different SCR-informed optimization objectives that prioritized different conservation goals by maximizing the number of protected individuals, reserve connectivity, and density-weighted connectivity. We also studied the effect on our 3 objectives of enforcing that the space-use requirements of individuals be met by the reserve for individuals to be considered conserved (referred to as home-range constraints). Maximizing local population density resulted in fragmented reserves that would likely not aid long-term population persistence, and maximizing the connectivity objective yielded reserves that protected the fewest individuals. However, maximizing density-weighted connectivity or preemptively imposing home-range constraints on reserve design yielded reserves of largely spatially compact sets of parcels covering high-density areas in the landscape with high functional connectivity between them. Our results quantify the extent to which reserve design is constrained by individual home-range requirements and highlight that accounting for individual space use in the objective and constraints can help in the design of reserves that balance abundance and connectivity in a biologically relevant manner.  相似文献   
950.
The Abnormal Situation Management® Consortium1 funded a study to investigate procedural execution failures during abnormal situations. The study team analyzed 20 publically available and 12 corporate confidential incident reports using the TapRoot® methodology to identify root causes associated with procedural execution failures. The main finding from this investigation was the majority of the procedural execution failures (57%) across these 32 incident reports were associated with abnormal situations. Specific recommendations include potential information to capture from plant incident to better understand the sources of procedural execution failures and improve use of procedures in abnormal situations.  相似文献   
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