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971.
An environmental study for the appraisal of work hazards and safety in Jeddah Industrial Estate (JIE), Saudi Arabia has been conducted. The study is based upon a representative (stratified random) sample of 44 enterprises, including 52 plants and employing 5830 workers. Nearly 2/3 of the workers have heat exposure, orginating from climatic heat and heat dissipated from industrial operations, while exposure to noise is slightly less, and is attributed to noisy operations and machinery and to lack of meticulous maintenance; both exposures are mild in most of the plants and moderate in some. Mild exposures to nonionizing radiations (UV and IR) and to deficient illumination occur in 25% and 19.2% of the plants studied. Respiratory exposure to chemical agents (organic and inorganic dusts, metal fumes, gases and vapours — including asphyxiants, irritants, liver and nervous system offenders and acid and alkali mists) occurs in 75% of the plants, particularly in the medium-size enterprises plants; however, is mainly mild with a few moderate and severe exposures. Skin absorption contributes to absorption of chemical agents in 29% of the plants, and direct skin contact to chemicals (particularly to lubricating oils) occurs in 81% of the plants. Meanwhile, only eight plants, out of the 32 plants where controls for physical hazards are required (51.2%), apply engineering controls, and even in a few of these plants the efficiency of the control measures has been rated ‘bad’. A few of them provide personal protective equipment, and even no maintenance to this equipment is provided. The level of safety is better in the large plants than in the small and medium-size plants; the safety score is the best in the recently established plants, while is the worst in the plastic industry, which is relatively old. The appraisal of fire protection is better than that of the safety, due to efficient supervision of the General Directorate of Civil Defense (GDCD). However, most of the safety problems are managerial and are preventable. First aid is present in all enterprises, as required by the Saudi Labor Laws; however, an in-plant medical service is present in 75% of the large enterprises, in 31.6% of the medium-size and in only 17.6% of the small enterprises. Also, satisfactory medical, accidents and absenteeism records exist in only 15.9% of the enterprises; safety supervision exists in 27.3, and safety education exists in 91% of them, while no environmental monitoring is carried out in any enterprise. Sanitation facilities exist in satisfactory numbers in most of the enterprises; however, their maintenance is poor in most of them, due to lack of hygienic supervision. All enterprises dispose of their liquid wastes into the JIE sewerage system without any treatment, while the solid wastes are collected by the city authorities in 56.8% of them; both wastes are anticipated to cause environmental pollution problems.  相似文献   
972.
Increased reliance on the Internet for critical infrastructure and the global nature of supply chains provides an opportunity for adversaries to leverage dependencies and gain access to vital infrastructure. Traditional approaches to assessing risk in the cyber domain, including estimation of impacts, fall short due to uncertainty in how interconnected systems react to cyber attack. This paper describes a method to represent the pathways of disruption propagation, evaluate the macroeconomic impact of cyber threats and aid in selecting among various cybersecurity policies. Based on state of the art agent-based modeling, multicriteria decision analysis, and macroeconomic modeling tools, this framework provides dynamic macroeconomic, demographic and fiscal insights regarding shocks caused by cyber attacks to the regional economy over time. The interlinkage of these models will provide a robust and adaptive system that allows policy makers to evaluate complex issues such as cybersecurity threats and their impacts on the geopolitical, social, environmental, and macroeconomic landscape.  相似文献   
973.
An oil spill on solid ice poses unique challenges to that of a spill on water or land. One challenge, which this study has elected to investigate, is the tendency of ice to crack and form channels. These channels are able to transport the oil away from the main mass of the spill making efficient cleanup difficult. Within the context of in situ burning, the oil channels may expedite the critical thickness of the oil spill being reached. A series of bench scale tests using a 100 cm long ice channel were conducted to study the effects of varying ice channel widths on the spread of an oil mixture, to mimic solid sea ice conditions that may be found in higher latitudes. Results suggest that spread rates of oil in ice channels approximately follows a viscous two-dimensional box model. The implication of these results on in situ burning of oil in icy conditions is discussed.  相似文献   
974.
Occupational accidents in the construction industry are more common compared with other fields and these accidents are more severe compared with the global average in developing countries, especially in Iran. Studies which lead to the source of these accidents and suggest solutions for them are therefore valuable. In this study a combination of the failure mode and effects analysis method and fuzzy theory is used as a semi-qualitative–quantitative method for analyzing risks and failure modes. The main causes of occupational accidents in this field were identified and analyzed based on three factors; severity, detection and occurrence. Based on whether the risks are high or low priority, modifying actions were suggested to reduce the occupational risks. Finally, the results showed that high priority risks had a 40% decrease due to these actions.  相似文献   
975.
On 22 May 1990 the Yemen Arab Republic and Peoples Democratic Republic of Yemen were unified to form the Republic of Yemen, with a population of about 14 million people in an area of about 580 000 km2. The Republic of Yemen is hoping to develop its mineral industry. Possessing a well established geological database plus a newly issued mining law and investment law, Yemen is inviting all investors, whether from the Yemeni private sector or foreign companies, either solely or in joint ventures to investigate opportunities in minerals and construction and industrial materials.  相似文献   
976.
Ozonation characteristics of synthetic Procaine Penicillin G (PPG) formulation effluent were investigated in a semi-batch ozone reactor at different pH (3, 7 and 12), ozone feed rates (600-2600 mg h-1) and COD values (200-600 mg l-1). Ozonation of aqueous PPG effluent resulted in 37 (82)% COD removal after 60 (120) min ozonation when the reaction pH was kept constant at pH=7.900 mg l-1 (corresponding to 50% of the total introduced) ozone was absorbed during a reaction period of 1 h. The effects of increasing the applied ozone dose and the initial COD on the COD abatement rates of PPG effluent were also studied. Results have indicated that increasing the ozone dose and decreasing the COD content both have positive effects on COD removal rates. The significant contribution of the free radical (.OH) reaction pathway to PPG ozonation could be traced using tert-butyl alcohol as the .OH probe compound at varying concentrations. The bimolecular reaction rate constants for the direct reaction of PPG with ozone were found as 152 and 2404 M-1 h-1 at pH=3 and 7, respectively, using the gas phase ozone partial pressures determined from of the outlet gas stream analysis. It could be demonstrated that ozone decomposition to free radicals being triggered by increasing the pH from 3 to 7 is essential for the rate enhancement of PPG effluent ozonation.  相似文献   
977.
Oxidative stress inducing potential of fly ash leachate (FAL) was studied in a freshwater fish, Channa punctata (Bloch). Fish were exposed to fly ash leachate for 24 h and lipid peroxidation (LPO) was studied as a marker of oxidative stress. Catalase (CAT), glutathione S-transferase (GST) activities and levels of reduced glutathione (GSH) were also estimated in the exposed fish. FAL (1 ml/l) induced LPO in all the organs and most prominent response was in the gill. It also caused induction of enzymes and glutathione. Liver showed highest level of induction of enzyme activities. The results of this study demonstrate that fly ash constituents have potential to induce oxidative stress in fish and gills are the most vulnerable organs. It is also suggested that in case of exposure to FAL, along with LPO antioxidant defense is also activated to counteract the reactive oxygen species (ROS) at least partly in the initial stages of exposure.  相似文献   
978.
Abstract: Flood management problems are inherently complex, time‐bound and multi‐faceted, involving many decision makers (with conflicting priorities and dynamic preferences), high decision stakes, limited technical information (both in terms of quality and quantity), and difficult tradeoffs. Multi‐Criteria Decision Support Systems (MCDSS) can help to manage this complexity and decision load by combining value judgments and technical information in a structured decision framework. A brief overview of MCDSS is presented, an original MCDSS architecture is put forth, and future research directions are discussed, including extensions to Multi‐Criteria Spatial Decision Support Systems and group MCDSS (as flood management involves shared resources and broad constituencies). With application to the September 11‐12, 2000 Tokai floods in Japan, the proposed multi‐criteria decision support instruments enhance communication among stakeholders and improve emergency management resource allocation. In summary, by making the links among flood knowledge, assumptions and choices more explicit, MCDSS increases stakeholder satisfaction, saves lives, and reduces flood management costs, thereby increasing decision‐making effectiveness, efficiency and transparency.  相似文献   
979.
Natural bentonite was treated by hydrochloric, nitric, and phosphoric acids followed by washing with sodium hydroxide in order to enhance its adsorption capacity. The sample that treated with hydrochloric acid followed by further treatment with NaOH showed the highest cation exchange capacity with a value of 51.20 meq/100 g. The zero-point of charge for this sample was found to be 4.50. Adsorption isotherms for both cobalt and zinc were fitted using Langmuir, Freundlich, and Redlich-Peterson and showed an adsorption capacity of 138.1 mg Co2+ and 202.6 mg Zn2+ per gram of treated sample.  相似文献   
980.
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