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1.
自然灾害变动的集成预测模型及其应用   总被引:7,自引:2,他引:7  
本文提出了以非线性回归拟合发展趋势、正弦函数逼近周期变动和马尔可夫链刻划随机扰动的集成预测模型,并应用于山东省农业自然灾害成灾面积的变动规律模拟,得到了较好的预测效果。理论和实践表明,集成预测模型优于传统的单模型预测,为预测具有复杂机制的自然灾害演变提供了一种新方法。  相似文献   
2.
The article states the case for greatly enhanced reliance on desalination in the provision of freshwater. It argues that the concept of integrated water resource management (IWRM), should be expanded to routinely include desalination, and that sea water and brackish water should be listed among available sources of freshwater. In recent years, the price per m3 of freshwater obtained from desalination has steadily declined, and is now within competitive range of conventional sources, especially as extracting water from surface sources (rivers, lakes) is becoming increasingly expensive as well as ecologically harmful, and groundwater in many locations is saline or depleted. With the expectation that by 2020, five billion people will reside in megacities, today's conventional water resources are likely to become insufficient. As many of these megacities are located near ocean coasts, sea water seems a logical solution.  相似文献   
3.
Current demand analysis methods do not formally cover the case of chronic deficits in quantity or quality of water and sanitation services. These services include drinking water supply (DWS), wastewater and sewage treatment (WST), and municipal solid waste management (MSW). Formal analysis of this case would, at minimum, define the deficit state and evaluate appropriate options for reducing it. This paper proposes for a formal analytical model for municipal sanitation systems (MSS) that operate with deficits in at least one of the constituent services of DWS, WST, or MSW. The model introduces definitions and notation for describing the deficit state for conducting demand analysis on municipal sanitation systems. This model of demand analysis for systems with chronic deficits will hereinafter be referred to as deficit analysis. A case study for Bacoor, Philippines is presented as an example.  相似文献   
4.
气候政策研究中的数学模型评述   总被引:3,自引:1,他引:3  
王灿  陈吉宁  邹骥 《上海环境科学》2002,21(7):435-439,454
按照成本分析和综合分析2个层次,分别介绍了投入产出模型、可计算一般均衡模型、宏观计量经济模型、工程经济模型、动态能源优化模型、能源系统模拟模型、综合评估模型等不同模型方法的特点及其在气候政策分析中的应用。指出可计算一般均衡模型是应用得最为广泛的方法之一。概括了气候政策模型研究的4个发展趋势,包括加强综合评估模型的应用、扩展成本与效益的内涵、注重不同模型之间的比较、强调不确定性分析。结果中国研究现状,分析了当前面昨的问题,认为国内气候政策模型研究与中国在国际气候变化领域的地位仍不相称,强度要进一步加强研究队伍建设、扩展研究领域、跟踪国际研究前沿问题,以便为国家的气候谈判政策提供更有效的科学依据和决策支持。  相似文献   
5.
Integrated Risk Framework for Onsite Wastewater Treatment Systems   总被引:1,自引:0,他引:1  
Onsite wastewater treatment systems (OWTS) are becoming increasingly important for the treatment and dispersal of effluent in new urbanised developments that are not serviced by centralised wastewater collection and treatment systems. However, the current standards and guidelines adopted by many local authorities for assessing suitable site and soil conditions for OWTS are increasingly coming under scrutiny due to the public health and environmental impacts caused by poorly performing systems, in particular septic tank-soil adsorption systems. In order to achieve sustainable onsite wastewater treatment with minimal impacts on the environment and public health, more appropriate means of assessment are required. This paper highlights an integrated risk based approach for assessing the inherent hazards associated with OWTS in order to manage and mitigate the environmental and public health risks inherent with onsite wastewater treatment. In developing a sound and cohesive integrated risk framework for OWTS, several key issues must be recognised. These include the inclusion of relevant stakeholders throughout framework development, the integration of scientific knowledge, data and analysis with risk assessment and management ideals, and identification of the appropriate performance goals for successful management and mitigation of associated risks. These issues were addressed in the development of the risk framework to provide a generic approach to assessing risk from OWTS. The utilisation of the developed risk framework for achieving more appropriate assessment and management techniques for OWTS is presented in a case study for the Gold Coast region, Queensland State, Australia.  相似文献   
6.
This article explores recent Australian experiences in the application of the concept of integrated urban water management (IUWM) to land development sites through the review of 15 case studies. It discusses lUWM’s emergence and comments on the success or otherwise of Australian experience in its application. The understanding of IUWM is maturing within the Australian water industry, an occurrence that has been facilitated by demonstration sites such as those reviewed. Successes include the translation of IUWM concepts into well-functioning operational urban developments, significant reductions in the impact of the urban developments on the total water cycle, and the increasing acceptance of the concept within the water and land development industries. However, there is still room for greater integration of the water supply, stormwater, and wastewater components of the urban water cycle, improved dissemination of knowledge, enhancement of skills in both public and private organisations, and monitoring the performance of systems and technologies.  相似文献   
7.
A coupled surface water-groundwater model of the Okavango Delta has been built based on the United States Geological Survey software MODFLOW 2000 including the SFR2 package for stream-flow routing. It will provide a new tool for evaluating water management and climate change scenarios. The delta's size and limited accessibility make direct, on the ground data acquisition difficult. Remote sensing methods are the most promising source of acquiring spatially distributed data for both model input parameters and calibration. Topography, aquifer thickness, channel positions, evapotranspiration and precipitation data are all based on remote sensing. Simulated flooding patterns are compared to patterns derived from visible to thermal NOAA-AVHRR data and microwave radar ENVISAT-ASAR data.  相似文献   
8.
In the last decade, the U.S. Food and Drug Administration (FDA) has issued several warnings and recalls for food products that exceed FDA standards for lead. Products containing chili peppers and salt were often suspected as sources of lead contamination, and included items such as candy that are routinely investigated. However, products such as hot sauces that contain similar ingredients have not been the focus of evaluations. This study quantified lead concentrations in imported hot sauces, evaluated product compliance to existing United States standards, and calculated potential dietary lead exposure for children using the Integrated Exposure Uptake Biokinetic Model. Finally, recommendations for reducing the risk of lead exposure from hot sauces are provided. Twenty-five (25) bottles of imported hot sauces manufactured in Mexico and South America were purchased in Clark County, Nevada. All hot sauces were analyzed for lead concentrations, pH, and leaded packaging. Hot sauces were analyzed by inductively coupled plasma mass spectrometry and packaging was analyzed using x-ray fluorescence technology. Four brands of hot sauces (16%) exceeded 0.1 ppm lead, the current FDA action level for lead in candy. Hot sauces with lead concentrations >0.1 ppm lead contained salt and were manufactured in Mexico. Subsequent analysis of additional lots of hot sauces exceeding 0.1 ppm lead revealed inconsistent lead concentrations between and within manufacturer lots. The lead concentrations of the plastic hot sauce lids ranged from below the limit of detection to 2,028 ppm lead. There was no association between lead concentrations in hot sauces and pepper type. These results indicate the need for more rigorous screening protocols for products imported from Mexico, the establishment of an applicable standard for hot sauce, and resources to allow for the enforcement of existing food safety policies. The data reported herein represent the first known investigation of lead concentrations in hot sauces.  相似文献   
9.
Secondary pest outbreak is a counterintuitive ecological backlash of pesticide use in agriculture that takes place with the increase in abundance of a non-targeted pest species after pesticide application against a targeted pest species. Although the phenomenon was well recognized, its alternative causes are seldom considered. Outbreaks of the southern red mite Oligonychus ilicis are frequently reported in Brazilian coffee farms after the application of pyrethroid insecticides against the coffee leaf miner Leucoptera coffeella. Selectivity favoring the red mite against its main predatory mites is generally assumed as the outbreak cause, but this theory has never been tested. Here, we assessed the toxicity (and thus the selectivity) of deltamethrin against both mite species: the southern red mite and its phytoseid predator Amblyseius herbicolus. Additionally, behavioral avoidance and deltamethrin-induced hormesis were also tested as potential causes of red mite outbreak using free-choice behavioral walking bioassays with the predatory mite and life-table experiments with both mite species, respectively. Lethal toxicity bioassays indicated that the predatory mite was slightly more susceptible than its prey (1.5×), but in more robust demographic bioassays, the predator was three times more tolerant to deltamethrin than its prey, indicating that predator susceptibility to deltamethrin is not a cause of the reported outbreaks. The predator did not exhibit behavioral avoidance to deltamethrin; however insecticide-induced hormesis in the red mite led to its high population increase under low doses, which was not observed for the predatory mite. Therefore, deltamethrin-induced hormesis is a likely cause of the reported red mite outbreaks.  相似文献   
10.
We propose a suite of actions for strengthening water governance in contexts with complex, multi-tiered arrangements. In doing so, we focus on the collective water policies and approaches of the United Kingdom (UK), including those of devolved governments, which confront a host of serious water-related challenges—from massive flooding of urban areas and agricultural lands, to pressure on aquifers from rising water demand and drought. Further complexity in addressing these challenges has emerged in the wake of the June 2016 vote to leave the European Union (EU), so-called ‘Brexit’, and the ensuing ‘separation process’ with uncertainties for institutional and governance arrangements to follow. We make ten proposals for improving and reinvigorating water policy in complex, multi-layered situations, and comment specifically on their application in the UK setting. These are: put in place a system-wide water policy; fully embrace community-led nested river basin planning and management; fully fund river basin planning and management; re-focus the policy framing; use best-available data and information; create conversational spaces and become a more water-literate society; mobilise people; support and sustain core community networks; underpin river basin plans with regulatory provisions and effective monitoring and enforcement; and address systemic institutional amnesia. Individually and collectively, we contend that these actions will have a marked effect on transforming the planning and management of water resources. A system-wide water policy that maintains and builds on the substantive biophysical and socio-economic benefits delivered through implementation of the EU Water Framework Directive, together with the more recent Floods Directive, will galvanise stewardship of water in the UK. We urge more active engagement with and empowerment of the multiplicity of system ‘actors’, and highlight the role of non-government actors in a post-Brexit world as conduits for reaching out to and connecting directly with a wide range of water-related actors, especially across the EU. While attention to-date has focused on a plethora of specifically water-related projects, initiatives, plans and regulations, what is really needed is a systemic, long-term view of water resource management.  相似文献   
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