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401.
应用发光菌测定有机化合物的毒性   总被引:11,自引:4,他引:11  
袁星  马梅 《环境化学》1994,13(3):255-258
本文介绍了化合物对发光菌半数抑制发光强度的毒性测定方法,测定了几十种芳烃类化合物的毒性,发现不同取代基或取代位置的芳烃毒性不同,并且对发光菌的毒性与对黑呆头鱼的毒性有相关性。  相似文献   
402.
403.
Many sites of former ammunition plants are contaminated with the explosive 2,4,6-trinitrotoluene, its derivatives and reduction products. Such nitroaromatic compounds have a high human and ecotoxic potential. Plant uptake of these organic pollutants is known and could be confirmed under field conditions. In this paper rhizospheric soil was analyzed to characterize the effect of vegetation on TNT-contaminated soil. Common beans (Phaseolus vulgaris) were used as test plants. The experiments were performed on two areas with different TNT concentrations. The data reveal a significant decrease of extractable TNT in rhizospheric soil by a factor of 5 to 6 during the vegetation period. On the area with high TNT concentration, an enrichment of nitroaromatic compounds in root tissue was found compared to the rhizospheric soil. Aminodinitrotoluene could be confirmed as the primary pollutant in the root. These results refer to a potential application of plants to biological remediation of soil contaminated with ammunition-specific pollutants.  相似文献   
404.
Ecotoxicological investigations focus on biological systems and their response to chemically induced stress. Experimental techniques are much more developed than deterministic dynamic modelling. In this methodological contribution a technique is presented, based on lattice theory. This technique, also calledHasse diagram technique, allows data analysis with respect to comparative evaluation. Hasse diagrams are used
  • ? to suggest a possible measure of microbial diversity,
  • ? to analyze dependencies between phospholipid fatty acids and simple geochemical parameters on an ordinal scale and
  • ? to visualise complex results of interactions of humic substances with xenobiotics.
  •   相似文献   
    405.
    In this paper, we specify susceptibility to drought from a psychology-based bottom-up perspective. On the basis of the protection motivation theory (Rippetoe and Rogers in J Pers Soc Psychol 52(3):596–604, 1987), we developed the protection-capacity model (Krömker and Mosler in Global environmental change in Alpine regions: impact, recognition, adaptation, and mitigation. Edward Elgar, Cheltenham, pp 93–112, 2002) to analyse the susceptibility with respect to the protection capacity of agents. The protection capacity is determined by the agents’ subjective assessment of the situation, which consists of the appraisal of threat, on the one hand, and the coping appraisal, on the other hand. Additionally, the protection-capacity model specifies several factors which influence the two central appraisal processes. Empirical data were collected in interviews with experts and with a total of 65 exemplarily selected households which are typical for the respective case study regions (Andhra Pradesh, India; Algarve and Alentejo, Portugal; Volgograd and Saratov, Russia). The data were analysed with the help of fuzzy set methodology. Results show that the households of the Indian region are the most susceptible when compared to those of the Russian region with ‘low’ and to households of the Portuguese region with a ‘very low’ degree of susceptibility. Moreover, we identified subgroups within the regions which are characterized by different degrees of susceptibility and a different profile of factors influencing susceptibility. Altogether, the agent-based perspective allows identifying relevant factors that need to be addressed to minimize susceptibility of the population and special subgroups. However, the results are not representative for the case study regions because of the small database. Additionally, more effort is needed to validate the findings.  相似文献   
    406.
    A lower molar of a haramiyoid mammal is described from the Toutunhe Formation of Liuhuanggou near Urumqi in the southern Junggar Basin, Xinjiang, China. It is referred to Eleutherodon sp., otherwise exclusively known from the Upper Bathonian of England. It is the first record of the order Haramiyida from Asia and the first Mesozoic mammal described from the southern Junggar Basin. Apart from the English specimens of Eleutherodon and Staffia from the Upper Jurassic of East Africa, it is the geologically youngest haramiyoid known. It is the first vertebrate taxon from the Toutunhe Formation that is probably not endemic and lends some support to the dating of the Formation as late Middle Jurassic, probably Bathonian.
    Michael W. MaischEmail:
      相似文献   
    407.
    首先结合方圆管理思想和PDCA持续改进原理,给出方圆论安全管理模式的定义,从核心理念、管理方法、管理程序与相关管理制度等方面阐释模式内涵;其次,论述模式的方圆循环原理和阶梯状上升原理,从方与圆两方面概括方圆论安全管理模式体系结构,并阐述方的管理思想和圆的管理思想;最后归纳概括模式的应用步骤,并阐述各个步骤的关键要素。该模式旨在将适于我国的管理思想融合与渗透到企业安全管理中,以期提高制度执行效率,最终实现企业安全生产目标。  相似文献   
    408.
    Retrofitting older vehicles with diesel particulate filter(DPF) is a cost-effective measure to quickly and efficiently reduce particulate matter emissions. This study experimentally analyzes real-world performance of buses retrofitted with CRT DPFs. 18 in-use Euro III technology urban and intercity buses were investigated for a period of 12 months. The influence of the DPF and of the vehicle natural aging on buses fuel economy are analyzed and discussed. While the effect of natural deterioration is about 1.2%–1.3%, DPF contribution to fuel economy penalty is found to be 0.6% to 1.8%, depending on the bus type. DPF filtration efficiency is analyzed throughout the study and found to be in average 96% in the size range of 23–560 nm. Four different load and non-load engine operating modes are investigated on their appropriateness for roadworthiness tests. High idle is found to be the most suitable regime for PN diagnostics considering particle number filtration efficiency.  相似文献   
    409.
    This paper reports a study of norovirus (NoV) GII distribution and persistence in Sydney rock oysters (SRO) (Saccostrea glomerata) located in an estuary after a pump station sewage overflow. SRO were strategically placed at six sites spanning the length of the estuary from the pump station to the sea. The spatial and temporal distribution of NoV, hepatitis A virus (HAV) and Escherichia coli (E. coli) in oysters was mapped after the contamination event. NoV GI and GII, HAV and E. coli were quantified for up to 48 days in oysters placed at six sites ranging from 0.05 to 8.20 km from the sewage overflow. NoV GII was detected up to 5.29 km downstream and persisted in oysters for 42 days at the site closest to the overflow. NoV GII concentrations decreased significantly over time; a reduction rate of 8.5% per day was observed in oysters (p < 0.001). NoV GII concentrations decreased significantly as a function of distance at a rate of 5.8% per km (p < 0.001) and the decline in E. coli concentration with distance was 20.1% per km (p < 0.001). HAV and NoV GI were not detected. A comparison of NoV GII reduction rates from oysters over time, as observed in this study and other published research, collectively suggest that GII reduction rates from oysters may be broadly similar, regardless of environmental conditions, oyster species and genotype.  相似文献   
    410.
    Seroprevalence data for pig herds suggested that there must be a relevant reservoir for hepatitis E virus (HEV) in Switzerland. To know more about the viral presence in ready-to-eat meat products, we screened pork liver sausages and raw meat sausages from the Swiss retail market for the presence of HEV. Testing was performed with a detection method where the virus extraction step was optimized. As for the performance of the improved method, the mean recovery rate for the mengovirus process control was 24.4%, whereas for HEV-inoculated sample matrices between 10.4 and 100% were achieved. The limit of detection was about 1.56 × 103 and 1.56 × 102 genome copies per gram for liver sausages and raw meat sausages, respectively. In the screening programme, HEV-RNA was detected in 10 of total 90 (11.1%) meat products, 7 of 37 (18.9%) liver sausages, and 3 of 53 (5.7%) raw meat sausages. Virus loads of up to 5.54 log10 HEV genome copies per gram were measured. All sequences retrieved from positive samples belonged to HEV genotype 3. The significance of the presented work was a current overview of the HEV prevalence in ready-to-eat meat products on the Swiss retail marked and an improvement of the extraction efficiency of the HEV detection method.  相似文献   
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