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211.
Five years of the annual Health Interview Survey, conducted by the National Center for Health Statistics, are used to estimate the effects of air pollution, smoking, and environmental tobacco smoke on respiratory restrictions in activity for adults, and bed disability for children. After adjusting for several socioeconomic factors, the multiple regression estimates indicate that an independent and statistically significant association exists between these three forms of air pollution and respiratory morbidity. The comparative risks of these exposures are computed and the plausibility of the relative risks is examined by comparing the equivalent doses with actual measurements of exposure taken in the homes of smokers. The results indicate that: (1) smokers will have a 55-75% excess in days with respiratory conditions severe enough to cause reductions in normal activity; (2) a 1 microgram increase in fine particulate matter air pollution is associated with a 3% excess in acute respiratory disease; and (3) a pack-a-day smoker will increase respiratory restricted days for a nonsmoking spouse by 20% and increase the number of bed disability days for young children living in the household by 20%. The results also indicate that the estimates of the effects of secondhand smoking on children are improved when the mother's work status is known and incorporated into the exposure estimate.  相似文献   
212.
对《民法通则》第124条和《环境保护法》第41条的误读,引发了我国环境法学界环境侵权民事责任构成要件的“违法性肯定论”与“违法性否定论”之争。上述两款法条,前者规范超标排污行为所导致的环境损害救济,其民事责任成立的“门槛”较高,但救济对象较广。后者则降低了环境侵权民事责任的“标准”,但缩小了救济对象。两者为环境污染的受害人提供了不同的救济途径,在司法实践中,应由法院根据个案选择适用。  相似文献   
213.
通过盆栽试验研究了Cd、Pb单一污染对龙须草生长全期干物质积累的影响。结果表明,在成熟期以前,Cd、Pb低浓度(不高于5mgCd/kg土)刺激能够促进龙须草植株干物质积累,高浓度(不低于200mgPb/kg土)刺激对龙须草干物质积累有抑制作用。被Cd、Pb污染的龙须草在成熟期时干物质积累总量比前一时期略微减小。Cd、Pb的临界浓度分别为5mgCd/kg土和200mgPb/kg土,表明龙须草干物质积累对Cd污染较Pb污染敏感。  相似文献   
214.
用动态规划模型求解最短路问题的研究   总被引:1,自引:0,他引:1  
动态规划法是求解具有多阶段的最短路径的算法,本文以动态规划理论为指导,研究了铺设管道最短路问题实例,采用顺序递推法和逆序递推法两种解决方法,并用LINGO软件编程得到结果.  相似文献   
215.
Regression Modelling of Disease Risk in Relation to Point Sources   总被引:1,自引:0,他引:1  
We describe a class of models for the investigation of possible raised risk of disease around putative sources of environmental pollution. An adaptation of the point process method suggested by Diggle and Rowlingson is presented, allowing the use of routinely available aggregated data and incorporating the more general distance–risk model suggested by Elliott and co-workers. An application to data on cancers of the stomach around municipal solid waste incinerators is presented.  相似文献   
216.
Symmetry and separability of a covariance function are common assumptions to simplify the modeling effort of spatial–temporal processes. However, many studies in environmental sciences show that real data have complex spatial–temporal dependency structures resulting from lack of symmetry or violation of other standard assumptions of the covariance function. In this study, we propose new formal tests for lack of symmetry by using spectral representations of the spatial–temporal covariance functions of regularly spaced spatial–temporal data. The advantage of the proposed tests is that classical analysis of variance (ANOVA) models can be used for detecting lack of symmetry inherent in spatial–temporal processes. We evaluate the performance of the tests with simulation studies and we apply them to air pollution data.  相似文献   
217.
中华人民共和国的建立和社会主义制度的形成,为中国实现工业化的发展目标奠定了坚实的制度基础.毛泽东从中国的实际出发,提出了"使中国由农业国变为工业国"、把中国"建设成为一个工业化的具有高度现代文化程度的伟大国家"的战略目标,并初步揭示了实现这一战略目标的发展道路、方针政策和科技依托等,形成了具有中国特色的国家工业化发展道路,奠定了中国现代化的重要基础.  相似文献   
218.
Health Risks of Energy Systems   总被引:1,自引:0,他引:1  
Health risks from fossil, renewable and nuclear reference energy systems are estimated following a detailed impact pathway approach. Using a set of appropriate air quality models and exposure-effect functions derived from the recent epidemiological literature, a methodological framework for risk assessment has been established and consistently applied across the different energy systems, including the analysis of consequences from a major nuclear accident. A wide range of health impacts resulting from increased air pollution and ionizing radiation is quantified, and the transferability of results derived from specific power plants to a more general context is discussed.  相似文献   
219.
为了解东西部地区公路线路基础设施使用效益的差异,从宏观层面建立了东西部地区客货运量与不同等级公路之间的结构方程模型,实证分析了东西部地区不同等级公路的使用效益。分析表明:东部地区除等外级公路以外,其他各等级公路的使用效益均高于西部地区;东部地区公路线路基础设施对货运量和货运周转量的效应均较大,西部地区公路线路基础设施对客运周转量的效应较大;由于经济发展阶段和产业结构特点不同,收费政策对东西部地区高速公路的使用效益产生了不同的影响。  相似文献   
220.
Low-cost housing provision has been a major focus of government in post-apartheid urban South Africa. While successes can be noted, there is growing concern regarding the social and environmental sustainability of housing programs and the impacts upon both the surrounding environment and human health. Utilizing key informant interviews, survey research, Census data and documentary review, this essay identifies the major impediments to a sustainable low-cost housing provision in urban South Africa. The essay also points to hopeful signs in new policy directions, particularly attention to health issues and informal settlement upgrade programs. However, the major obstacles to a sustainable low-cost housing process, including macro-economic conditions, enduring historical legacies of race and class, the scale and rapidity of urban growth and institutional challenges show little indication of abating.  相似文献   
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