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831.
832.
The scope of this study covers events resulting from improper functioning of machine control systems. An accident model providing a basis for formulating a checklist for accident analysis has been developed. Data about 700 accidents were collected. An analysis has proved that in the group of accidents caused by improper functioning of machine control systems, serious accidents happened much more frequently as compared to the group of accidents with no relation to the control system. The reasons for the majority of incidents caused by improper performance of safety functions consist in the errors made by designers. In view of that, incorrect behaviour of a worker should be treated as a normal event instead of a deviation causing an accident.  相似文献   
833.
The aim of the study was to examine the effects of wearing an ice-vest (ca 1 kg) on physiological and subjective responses in fire fighters. The experiments were carried out on a treadmill in a hot-dry environment. The physical cooling effect of the ice-vest was measured with a thermal manikin. The ice-vest effectively reduced skin temperatures under the vest. On average, heart rate was 10 beats/min lower, the amount of sweating was reduced by 13%, and subjective sensations of effort and warmth were lower during work with the ice-vest compared to work without it. Thermal manikin tests indicated that the useful energy available from the vest for body cooling was rather high (58%). In conclusion, the ice-vest reduces physiological and subjective strain responses during heavy work in the heat, and may promote efficient work time by 10%.  相似文献   
834.
Research on work aggression or anger has typically focused on supervisors and co‐workers as the instigators of aggression; however, aggressive customers are also likely and may have unique consequences for the employee. We explore this phenomenon with a sample of 198 call center employees at two work sites. The employees reported that customer verbal aggression occurred 10 times a day, on average, though this varied by race and negative affectivity. Using LISREL, our data indicated that both the frequency and stress appraisal of customer aggression positively related to emotional exhaustion, and this burnout dimension mediated the relationship of stress appraisal with absences. Stress appraisal also influenced employees' emotion regulation strategies with their most recent hostile caller. Employees who felt more threatened by customer aggression used surface acting or vented emotions, while those who were less threatened used deep acting. Job autonomy helped explain who found these events more stressful, and implications of these results are discussed. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   
835.
This paper reviews relevant literature on the sustainability indicators theoretically proposed and practically applied by scholars over the past 15 years. Although progress is being made in the development and critical analysis of sustainability indicators, in many cases existing or proposed indicators are not the most sensitive or useful measures in developing countries. Indicator selection needs to meet the following criteria: relative availability of data representing the indicators, sensitivity to stresses on the system, existence of threshold values and guidelines, predictivity, integratability and known response to disturbances, anthropogenic stresses, and changes over time. Based on these criteria, this paper proposes a set of operational indicators for measuring agricultural sustainability in developing countries. These indicators include ecological indicators involving amounts of fertilizers and pesticides used, irrigation water used, soil nutrient content, depth to the groundwater table, water use efficiency, quality of groundwater for irrigation, and nitrate content of both groundwater and crops. Economic indicators include crop productivity, net farm income, benefit–cost ratio of production, and per capita food grain production. Social indicators encompass food self-sufficiency, equality in food and income distribution among farmers, access to resources and support services, and farmers knowledge and awareness of resource conservation. This article suggests that the selection of indicators representing each aspect of sustainability should be prioritized according to spatial and temporal characteristics under consideration.  相似文献   
836.
BACKGROUND AND INTENTION: Aromatic sulphonates other than surfactants and their hydroxy and amino-derivatives are important intermediates for the production of azo dyes. Their production on a large scale can be detrimental for the environment, if the by-products of their synthesis are not disposed of appropriately. An industrial waste, the organic components of which were mainly amino and hydroxy-substituted aromatic sulphonates, seriously endangers the environment close to an dismissed Italian industrial site. Inorganic sulphates and chlorides contained in the waste seriously hinder its disposal by incineration, since they corrode furnace walls. In this work, preliminary exploration of aqueous-phase electrochemically and photochemically induced oxidation techniques have been performed as possible alternatives to incineration. METHODS: Electrochemically-induced oxidation was experimented on individual aromatic sulphonates and on an industrial waste by electrolysing them between smooth platinum electrodes at low temperature (5 degrees C) and high current densities (0.4 A/cm2) with aqueous 0.5 M NaHSO4 electrolyte. Photochemically-induced oxidation was performed by irradiating individual aromatic sulphonates or industrial waste with a 500 W mercury lamp in the presence of sodium peroxydisulphate. RESULTS AND DISCUSSION: After 200 min electrodegradation, 90% of the original compounds disappeared, while 50% Total Organic Carbon (TOC) of an industrial waste was removed from solution after 10 hours. After 180 min UV-photodegradation, 90% of two test aromatic sulphonates disappeared, while 65% of TOC of industrial waste was removed after 5 hours. CONCLUSIONS: Two methods, electrochemical and UV-persulphate oxidation of an industrial waste, were used in order to propose a disposal procedure alternative to incineration. Electrodegradation with smooth Pt anode in 0.5 M NaHSO4 at 5 degrees C halved TOC concentration within 10 hours, while persulphate-assisted UV-photochemical oxidation with a 500 W high pressure Hg lamp abated two-thirds of TOC concentration after 5 hours. Energetic consumption of electrodegradation was 0.33 kWh/g TOC, while that of photooxidation was larger than 2 kWh/g TOC. Although both techniques can be considered efficient from a purely chemical point of view, since both are capable of wet-oxidising the aromatic sulphonates and the industrial waste, electrodegradation seems more promising than a photochemical degradation if economical considerations are also taken into account. Considering also that neither cell design nor catalyst were optimised in this preliminary study, the energy yield of electrodegradation seems likely to be largely improved.  相似文献   
837.
Following their exposure to anthracene, the roots of Populus nigra L. Loenen showed traces of 9 substances classed as products of biodegradation. The main substances detected were phthalic acid and 9,10-anthraquinone, followed by hydroxyanthracene and methoxyanthracene and five other compounds which could not be identified. Due to the relatively low concentration of degradation products found in the roots, further degradation to lower molecular compounds are discussed. The presence of 9,10-anthraquinone as the main product of the degradation of anthracene was also evident in the control tests with unplanted sandy substrate, although the content was higher in the planted series of tests. As a non-sterile approach was chosen, it may be assumed that a microbial degradation for 9,10-anthraquinone took place in the control series. However, it is difficult to differentiate clearly between a microbial degradation of anthracene in the substrate and metabolization in the roots due in part to the absence of specific degradation products in the various reaction areas.  相似文献   
838.
The contemporary copper cycle of Asia   总被引:11,自引:1,他引:10  
A regional stock and flow model for an industrial metal was developed based on the substance-flow framework. Using this model, the contemporary copper cycle of the Asian region was constructed by aggregating country-level production and import and export data for different stages of the copper cycle. The reliability and availability of data were assessed both qualitatively and quantitatively. Asia as a region is a net importer of copper. There is a significant build-up of copper in use at a rate of nearly 3TgCu/year. The per capita generation of copper waste (0.4kgCu/(capita-year)) and the rate of secondary recovery of copper are low compared with Europe and North America. Japan's rates of use, waste generation, and recycling of copper are all much larger than the continental average. A tremendous potential exists in the region to utilize the copper content of the in-use reservoir, and subsequently to enhance copper recycling rates in the future. A set of metrics for the copper cycle is suggested in order to address sustainability issues related to resource policy and the environmental management of copper.  相似文献   
839.
Environmental management systems (EMSs), such as International Organization for Standardization (ISO) 14001, can be used as a tool in China by industrial park managers to improve their environmental performance. This article uses the case of the Dalian Economic and Technological Development Zone (DETDZ) to show how to establish a comprehensive environmental management system (CEMS) according to the ISO 14001 standard at the industrial park level by considering local realities. The particularly interesting feature of this case study is the use of a CEMS (in this case, ISO 14001) by the administrative group of the DETDZ to develop a more comprehensive approach to the wide range of environmental issues that they face in running the zone. In essence the goal is to address many of the issues at the level of the zone. The incentives, benefits, and barriers associated with implementing ISO 14001 are described. However, implementation of an EMS should not be thought of as the ultimate objective for an industrial parks environmental management. The next steps include encouraging further public participation and taking an integrated approach leading to an industrial ecosystem, which can realize better environmental performance at the industrial park level. Yong Geng is currently a Ph.D. candidate at Dalhousie University. Raymond Côté is a professor at Dalhousie University.  相似文献   
840.
Influence of Geoengineered Climate on the Terrestrial Biosphere   总被引:3,自引:0,他引:3  
Various geoengineering schemes have been proposed to counteract anthropogenically induced climate change. In a previous study, it was suggested that a 1.8% reduction in solar radiation incident on the Earths surface could noticeably reduce regional and seasonal climate change from increased atmospheric carbon dioxide (CO2). However, the response of the terrestrial biosphere to reduced solar radiation in a CO2-rich climate was not investigated. In this study, we hypothesized that a reduction in incident solar radiation in a Doubled CO2 atmosphere will diminish the net primary productivity (NPP) of terrestrial ecosystems, potentially accelerating the accumulation of CO2 in the atmosphere. We used a dynamic global ecosystem model, the Integrated Biosphere Simulator (IBIS), to investigate this hypothesis in an unperturbed climatology. While this simplified modeling framework effectively separated the influence of CO2 and sunlight on the terrestrial biosphere, it did not consider the complex feedbacks within the Earths climate system. Our analysis indicated that compared to a Doubled CO2 scenario, reduction in incident solar radiation by 1.8% in a double CO2 world will have negligible impact on the NPP of terrestrial ecosystems. There were, however, spatial variations in the response of NPP-engineered solar radiation. While productivity decreased by less than 2% in the tropical and boreal forests as hypothesized, it increased by a similar percentage in the temperate deciduous forests and grasslands. This increase in productivity was attributed to a 1% reduction in evapotranspiration in the Geoengineered scenario relative to the Doubled CO2 scenario. Our initial hypothesis was rejected because of unanticipated effects of engineered solar radiation on the hydrologic cycle. However, any geoengineering approaches that reduce incident solar radiation need to be thoroughly analyzed in view of the implications on ecosystem productivity and the hydrologic cycle.  相似文献   
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