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71.
Meteorological-driven processes exert large and diverse impacts on lakes and their water quality; these impacts can be hydrologic, thermal, hydraulic, chemical, biochemical, or ecological. The impact of climate change on Lake Tahoe (California–Nevada) was investigated here as a case study of climate change effects on the physical processes occurring within lakes. The already published trends of meteorological variables were used to assess the effects of global warming on Lake Tahoe dynamics. Records from the period 1969–2002 show that Lake Tahoe has became warmer and more stable. A series of simulation years into the future (i.e., 2000–2040) was established using flows, loads, and meteorology data sets for the period 1994–2004. Results of 40-year simulations show that the lake continues to become warmer and more stable, and mixing is reduced. Possible changes in water quality because of global warming are discussed through inference, although these are not specifically simulated. Many existing problems may be exacerbated due to climate change, yet extreme uncertainty depends on the rate and magnitude of climate change. Therefore, shifts in water quality and quantity due to climate change should be integrated into contemporary planning and management in an adaptive manner, and the research and development of impact assessment methodology should focus on approaches that can handle extreme uncertainty. The general alternatives for lake management due to climate change are discussed. Depending on the specific case, further intensive research is suggested to restore lake water quality.  相似文献   
72.
Computer-supported visualization of rescue operations   总被引:1,自引:0,他引:1  
Effective emergency management and response require a thorough understanding of the processes involved in a rescue operation and their interaction. Appropriate methods and tools for computer visualization of rescue operations can greatly facilitate activities such as command and control, system analysis, training, evaluation, and transfer of lessons learned. To this end, we introduce a method for systematic analysis, modeling and visualization of a rescue scenario. Models of rescue scenarios, prepared in advance, serve as the basis for data collection during an operation. The data collected are visualized in a computer tool with several views that can be customized according to the needs of different users. We demonstrate the method by applying it to a rescue operation where a taskforce trains for emergency response to a chemical incident.  相似文献   
73.
传统的大学英语教学模式以教师课堂分析和语言讲解为重点,学生进行的实践太少。教学内容难以靠近语意和语境,学生很难做到学以致用。相反,情景教学能极大地激发学生的学习兴趣,积极引导学生参与语言练习。在情景教学中,教师通过创设情景、带入情境、运用情境、情景反思四步骤带领学生完成课堂任务,达到语言学习的目的。  相似文献   
74.
Abstract: The need to adapt to climate change has become increasingly apparent, and many believe the practice of biodiversity conservation will need to alter to face this challenge. Conservation organizations are eager to determine how they should adapt their practices to climate change. This involves asking the fundamental question of what adaptation to climate change means. Most studies on climate change and conservation, if they consider adaptation at all, assume it is equivalent to the ability of species to adapt naturally to climate change as stated in Article 2 of the United Nations Framework Convention on Climate Change. Adaptation, however, can refer to an array of activities that range from natural adaptation, at one end of the spectrum, to sustainability science in coupled human and natural systems at the other. Most conservation organizations deal with complex systems in which adaptation to climate change involves making decisions on priorities for biodiversity conservation in the face of dynamic risks and involving the public in these decisions. Discursive methods such as analytic deliberation are useful for integrating scientific knowledge with public perceptions and values, particularly when large uncertainties and risks are involved. The use of scenarios in conservation planning is a useful way to build shared understanding at the science–policy interface. Similarly, boundary organizations—organizations or institutions that bridge different scales or mediate the relationship between science and policy—could prove useful for managing the transdisciplinary nature of adaptation to climate change, providing communication and brokerage services and helping to build adaptive capacity. The fact that some nongovernmental organizations (NGOs) are active across the areas of science, policy, and practice makes them well placed to fulfill this role in integrated assessments of biodiversity conservation and adaptation to climate change.  相似文献   
75.
土地利用变化情景下牧羊河水文响应研究   总被引:2,自引:0,他引:2  
土地利用方式变化影响水量平衡各要素的分配,进而导致流域水源涵养能力发生变化。选用长江流域金沙江水系下段牧羊河小流域内及周边气象站气象资料,植被、土壤以及地形数据,构建了研究区SWAT水文模型,分析其在牧羊河适用性后,结合1986~2009年的土地利用以及设置的人类活动增强和生态环境改善的4种土地利用变化情景,用率定好的SWAT模型分析了土地利用变化下牧羊河水文响应。结果表明:径流依次按1986、2000、2009、1995年土地利用方式减小,而蒸散依次按2009、1986、2000、1995年土地利用方式减小,土地利用对径流和蒸散的影响在汛期大于非汛期,随着林地面积的增加径流将减小;将现有耕地变为林地或变为草地都有助于减少径流,从流域水源水量涵养角度出发,构建适宜的生态系统将有助于减少径流和蒸散,而增加入渗。这一结果为牧羊河水源涵养林建设提供科学依据  相似文献   
76.
利用WCRP的耦合模式数据和长江上游流域63个气象站点的观测数据,评估了全球气候模式对长江上游流域的温度、降水的模拟能力,基于A2、A1B、B1情景对长江上游流域未来50 a平均温度、降水的可能变化进行了预估研究。结果表明:全球模式可较好的反映出流域温度、降水的时间和空间变化趋势,但模拟地面温度总体上低于实况值〖HT5〗。〖HT5"〗三种情景下2011~2060年上游流域平均温度的增幅(相对于1971~2000年)分别为1.7℃、2.1℃、1.3℃。A1B、B1情景下区域内表现为一致的增温趋势,而A2情景下在嘉陵江流域出现降温的趋势。三种情景下平均降水的增幅分别为50.0、83.5、29.5 mm;A1B、B1情景下降水增加的空间分布形比较一致  相似文献   
77.
介绍了事故场景概念,并根据欧盟ARAMIS项目框架下提出的MIMAH(辨识重要事故危险方法),即从危险设备的角度来辨识与设备相关的关键事件,并利用事故树( FTA )、事件树( ETA),建立一个以关键事件为中心的蝴蝶结结构图来描述事故场景。通过运用这种方法,能够对事故场景的辨识更加具有系统性、针对性。最后,以液氨储罐装置作为示例进行说明。  相似文献   
78.
This article presents the evaluation of a pilot project where four decision-making tools were applied in a municipal energy-planning process in a Swedish municipality. The tested tools were citizens' panel, a scenario method, life cycle assessment and qualitative checklists for environmental assessment (EA). The results presented are based on two focus group discussions with the participants from the project: one with the municipal workgroup and one with the researchers that were responsible for the application of the decision-making tools. The results show that energy planning is a process of learning and dialogue, and workshop methodology was found to be favourable for open dialogue. This test also shows that public involvement can contribute to a valuable dialogue in the visionary work and suggestions of actions and strategies. Another conclusion is that energy planning needs to be iterative, even in the scoping. This test also shows that there is a need to develop simplified tools that include EA and a broad systems approach in local energy planning.  相似文献   
79.
任国友  王文涛  刘旭 《安全》2019,40(8):11-16
为了解决机场类公众聚集场所乘客群体行为及其控制的难点问题,以首都机场T3航站楼作为仿真对象,利用MassMotion软件,对T3航站楼内部行人交通组织与登机离港服务关键情景进行仿真模拟,揭示了在工作日和假期情景下,首都机场T3航站楼进站与登机离港时行人流特征。研究结果,首都机场T3航站楼行人流量与密度在水平通道处呈二元函数关系,速度与密度的关系相比密度与流量的关系更为复杂,密度适中时,两者呈线性关系;密度较大,行人拥挤时,呈对数关系;密度较小时,呈指数关系。因此,科学预测节假日高峰期行人流平均密度是机场类公众聚集场所风险控制的关键措施。  相似文献   
80.
Carbon dioxide emission reduction scenarios for Finland are compared with respect to the radiative forcing they cause (heating power due to the absorption of infrared radiation in the atmosphere). Calculations are made with the REFUGE system model using three carbon cycle models to obtain an uncertainity band for the development of the atmospheric concentration. The future emissions from the use of fossil fuels in Finland are described with three scenarios. In the reference scenario (business-as-usual), the emissions and the radiative forcing they cause would grow continuously. In the scenario of moderate emission reduction, the emissions would decrease annually by 1% from the first half of the next century. The radiative forcing would hardly decrease during the next century, however. In the scenario of strict emission reductions, the emissions are assumed to decrease annually by 3%, but the forcing would not decrease until approximately from the middle of the next century depending on the model used. Still, in the year 2100 the forcing would be considerably higher than the forcing in 1990. Due to the slow removal of CO2 from the atmosphere by the oceans, it is difficult to reach a decreasing radiative forcing only by limiting fossil CO2 emissions. The CO2 emissions from fossil fuels in Finland contribute to the global emissions presently by about 0.2%. The relative contribution of Finnish CO2 emissions from fossil fuels to the global forcing due to CO2 emissions is presently somewhat less than 0.2% due to relatively smaller emissions in the past. The impact of the nonlinearity of both CO2 removal from the atmosphere and of CO2 absorption of infrared radiation on the results is discussed.  相似文献   
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