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711.
Three periods or stages can be recognized in the development of medicine in China. The first one, being the indigenous medical practice, has its own philosophical approach and can therefore not simply be combined with Western medicine. The second period, in which medical missionaries introduced modern medicine was still a time of laissez-faire and pestilence. The third stage was ushered in by the liberation in 1949 and is characterized by the fact that the government no longer regards health as the private affair of the individual but as a task for the whole community. A number of endemic and epidemic diseases were conquered mainly through close cooperation between the population and medical workers. Success must be regarded as in an important part due to land reform and the eradication of famine. Further improvement in health care will depend to a great deal on improvement in living standards and a lessening of population pressure. As family planning meets resistance for economic and other reasons, only specific measures by the state can bring about a change in attitude. The progress in preventive measures is matched by advances in the technical aspects of medicine and especially too in medical education.  相似文献   
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The purpose of the present statistical analysis was the assessment of the relation between time series of environmental factors and of frequencies of diseases of the respiratory system in pre-school children. During about one year, daily measurements of air pollutants and climatic variables were taken. During the same period of time two series of medical data were collected: (i) The daily relative number of pre-school children, exhibiting diseases of the respiratory tracts who either came to the outpatients' clinic of the children's hospital or were reported by paediatricians in Basle (ENTRIES). (ii) The daily relative frequency of symptoms of the respiratory tracts observed in a group of randomly selected pre-school children (SYMPTOMS).By means of transfer function models the relation between the two target variables and the explaining variables was analysed. Several practical problems did arise: Choice of the appropriate transformation of the different series, interpretation of the crosscorrelation function using different methods of prewhitening, time splitting and nonstationarity of the crosscorrelation structure. In particular, it was found that after prewhitening the crosscorrelation function between the explanatory series SO2 and the response series SYMPTOMS changes with time. While during the winter period an instantaneous relation between these two series (and to a lesser extent between NO2 and SYMPTOMS) was identified, no such relation was found for the other seasons.  相似文献   
714.
The objective of this study was to compare measured concentrations of rubber process dust and rubber fume originating from different sources in the British rubber manufacturing industry. Almost 8000 exposure measurements were obtained from industry-based survey results collected by the British Rubber Manufacturers' Association (BRMA), and covering the years 1977 to 2002, and from a series of small surveys contained in the Health and Safety Executive's (HSE) National Exposure Database (HSE-NEDB) from 1980 to 2002. The analysis investigated temporal trends in the exposure concentrations and the underlying main factors responsible for these changes. Analyses were carried out using hierarchical linear mixed effects models. Average personal exposures to rubber process dust and rubber fumes were respectively a factor 2 and 4 higher for the HSE-NEDB data when compared to data originating from the industry (BRMA data). Personal exposure to rubber process dust decreased on average by 4.1% (95% CI 4.7-3.6) annually for the BRMA data and slightly less at 2.3% (95% CI 5.2-0.7%) per annum for the HSE-NEDB data. Personal exposure to rubber fume also showed a downward temporal trend of 2.9% (95% CI 3.6-2.3%) and 4.8% (95% CI 7.4-2.1%) annually for the BRMA and HSE-NEDB data, respectively. These trends differed considerably between departments. No major changes in the estimated temporal trends in exposure concentrations were observed after including the presence of local exhaust ventilation in the models for any department in the BRMA and HSE-NEDB datasets. Lack of information on the quality and status of the local exhaust ventilation is the most likely explanation for this. In conclusion, even though there were relatively similar downward time trends in both rubber process dust and fume concentrations in both datasets, the source of exposure data was an important determinant of average exposure concentrations present in the British rubber manufacturing industry. Lack of detailed auxiliary information on company size, reason for sampling, measurement strategy and other potentially important determinants of exposure prevented an explanation for the observed differences in exposure level.  相似文献   
715.
Radioimmunologic assay techniques are superior to most analytical procedures with regard to sensitivity, precision, general applicability, and experimental simplicity. Both for diagnosis and for monitoring of therapy this method has greatly advanced our understanding of endocrine physiology. Besides its use in clinical chemistry, radioimmunoassay is also employed in pharmacology, toxicology, and in pharmacokinetics of new drugs.  相似文献   
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The present paper is a call to cultural sciences for helping climate science to establish a sustainable practice of policy advice concerning man-made climate change.As a climate scientists engaged in communication with stakeholders and the media, mostly in Germany, the author has noticed a notable discrepancy between scientific knowledge about climate change, and the understanding in the public at large, specifically as fostered by the media and some publicly visible climate scientists. In this essay, this discrepancy is analysed to some extent and framed as the presence of two competing types of knowledge, namely a body of knowledge named “cultural construct” and another body of knowledge named “scientific construct” of man-made climate change. The relationship and the dynamics of these two knowledge claims are not well researched. In order to understand the dynamical interaction of the different knowledge claims significant efforts from cultural sciences are needed. Unfortunately, so far these disciplines do not often consider this field. Two examples of useful analyses are presented as examples.  相似文献   
719.
A mechanistic model was developed to assess the impact of predation of juvenile Notonecta maculata on size structured Daphnia magna populations and to provide a framework for quantifying the backswimmers uptake of food. Results of experiments and model predictions clearly demonstrate selective predation of backswimmers when fed with a choice of daphnid size classes, with patterns of selectivity differing across N. maculata instars. The model describes the foraging process empirically on the base of a general predation cycle including four conditional events instead of using classic functional response curves. For model parameterisation components of predation, namely probability of encounter, attack and success as well as time spent on handling prey was directly observed by means of video tracking experiments. Since attack rate, capture success and handling time appeared to be a function of prey size differing between Notonecta instars, the model takes into account ontogenic changes in both predator and prey characteristics. Independent data of functional response and size selectivity experiments were used for model validation and proved the model outcome to be consistent with observations.  相似文献   
720.
Traditionally, evolutionary ecology and conservation biology have primarily been concerned with how environmental changes affect population size and genetic diversity. Recently, however, there has been a growing realization that phenotypic plasticity can have important consequences for the probability of population persistence, population growth, and evolution during rapid environmental change. Habitat fragmentation due to human activities is dramatically changing the ecological conditions of life for many organisms. In this review, we use examples from the literature to demonstrate that habitat fragmentation has important consequences on oviposition site selection in insects, with carryover effects on offspring survival and, therefore, population dynamics. We argue that plasticity in oviposition site selection and maternal effects on offspring phenotypes may be an important, yet underexplored, mechanism by which environmental conditions have consequences across generations. Without considering the impact of habitat fragmentation on oviposition site selection, it will be difficult to assess the effect of fragmentation on offspring fitness, and ultimately to understand the impact of anthropogenic-induced environmental change on population viability.  相似文献   
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