首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   2323篇
  免费   103篇
管理学   357篇
民族学   14篇
人才学   1篇
人口学   161篇
丛书文集   13篇
理论方法论   287篇
综合类   10篇
社会学   1313篇
统计学   270篇
  2023年   17篇
  2022年   9篇
  2021年   17篇
  2020年   39篇
  2019年   65篇
  2018年   70篇
  2017年   93篇
  2016年   83篇
  2015年   57篇
  2014年   94篇
  2013年   373篇
  2012年   74篇
  2011年   73篇
  2010年   89篇
  2009年   75篇
  2008年   92篇
  2007年   91篇
  2006年   89篇
  2005年   69篇
  2004年   76篇
  2003年   70篇
  2002年   68篇
  2001年   62篇
  2000年   47篇
  1999年   49篇
  1998年   45篇
  1997年   49篇
  1996年   27篇
  1995年   41篇
  1994年   30篇
  1993年   30篇
  1992年   24篇
  1991年   36篇
  1990年   24篇
  1989年   13篇
  1988年   14篇
  1987年   11篇
  1986年   11篇
  1985年   16篇
  1984年   21篇
  1983年   18篇
  1982年   17篇
  1981年   8篇
  1980年   8篇
  1979年   9篇
  1978年   5篇
  1977年   8篇
  1976年   7篇
  1975年   6篇
  1974年   3篇
排序方式: 共有2426条查询结果,搜索用时 31 毫秒
201.
Input‐output analysis is frequently used in studies of large‐scale weather‐related (e.g., Hurricanes and flooding) disruption of a regional economy. The economy after a sudden catastrophe shows a multitude of imbalances with respect to demand and production and may take months or years to recover. However, there is no consensus about how the economy recovers. This article presents a theoretical route map for imbalanced economic recovery called dynamic inequalities. Subsequently, it is applied to a hypothetical postdisaster economic scenario of flooding in London around the year 2020 to assess the influence of future shocks to a regional economy and suggest adaptation measures. Economic projections are produced by a macro econometric model and used as baseline conditions. The results suggest that London's economy would recover over approximately 70 months by applying a proportional rationing scheme under the assumption of initial 50% labor loss (with full recovery in six months), 40% initial loss to service sectors, and 10–30% initial loss to other sectors. The results also suggest that imbalance will be the norm during the postdisaster period of economic recovery even though balance may occur temporarily. Model sensitivity analysis suggests that a proportional rationing scheme may be an effective strategy to apply during postdisaster economic reconstruction, and that policies in transportation recovery and in health care are essential for effective postdisaster economic recovery.  相似文献   
202.
Protecting riparian corridors is a commonly applied environmental policy in urban landscapes. However, empirical data demonstrating their efficacy for biodiversity conservation outcomes is scarce. In this study we investigated whether riparian corridor width influences the diversity and community structure of ant (Hymenoptera: Formicidae) and vascular plant assemblages therein. Eighteen corridors of differing widths were selected from within the Ku-ring-gai Local Government Area, Sydney Australia. Ants were sampled using pitfall traps positioned within rectangular vegetation transects (30 × 10 m). Both ant and plant species richness, when standardised for sampling effort, were unrelated to riparian corridor width. However, significant compositional differences between sites were evident with increased width up to ~50 m. Narrow corridors contained greater abundances of opportunistic ant species and higher proportions of exotic plants. We interpret this to be the result of the greater disturbance/edge influence derived from adjacent upland urban environments. Site beta diversity did not increase with corridor width, suggesting that the exclusion of novel upslope habitats in narrow riparian corridors is not a significant cause of community assemblage modification at these sites. To minimise the impact of deleterious edge effects on ant fauna, environmental managers should seek to retain riparian corridors wider than ~50 m. However, we observed substantial between-site variability of biotic assemblages, irrespective of corridor width. Therefore we recommend that environmental management practice needs to take a catchment-wide approach and consider other parameters that may contribute to riparian health so as to optimise the protection of riparian biodiversity.  相似文献   
203.
All children in the Czech Republic have the legal right to primary education, regardless of nationality and legal status. This article is based on a study of refugee children and their educational situation. The study reveals that refugee students in the Czech Republic are not benefiting fully from this fundamental right and that their educational future is in jeopardy. The study identified six major barriers to full participation and educational benefits. Finally, a plan of action to overcome barriers is put forward. Key ingredients are effective information transfer among state agencies, non‐governmental organizations, parents, children and schools.  相似文献   
204.
Neural correlates of anticipatory and reactive saccades were studied in 4‐month‐old infants by recording high‐density event‐related potentials. Infants were presented with a fixed sequence of stimulus presentation to which they rapidly showed anticipatory saccades, as well as continuing with some reactive (stimulus‐driven) saccades. As in a previous study, no clear evidence was found for adultlike, saccade‐related potentials, although some presaccadic differences between reactive and anticipatory saccades were observed. Infants also showed different stimulus offset‐related effects preceding the 2 types of trials with a right‐frontal positivity when an anticipatory look follows, but only left‐frontal positivity when a reactive saccade follows.  相似文献   
205.
206.
Assume independent random samples are drawn from two populations which are exponentially distributed with unknown location parameters and a common known scale parameter. We want to estimate the maximum and the minimum of the unknowo location paremeters. In this paper several estimators are proposed which are better than the natural estimations in terms of absolute bias and /or meaqn squared error.  相似文献   
207.
We test the mediated effects of participation in employee involvement (EI) programs on employee desires for union involvement in the future development and diffusion of EI and the perceived durability of an EI program as a possible moderator of these effects. Results indicate that participants developed more positive attitudes toward the EI program than nonparticipants and, in turn, these attitudes were related to higher desires for union involvement in EI. Additionally, volunteers developed more positive attitudes toward the EI program than nonvolunteers and, in turn, these attitudes were related to higher desires for union involvement in EI. However, the relationship between attitudes toward EI and desires for union involvement in EI was significantly less positive for participants who viewed the EI program as durable.  相似文献   
208.
209.
210.
Model-based clustering for social networks   总被引:5,自引:0,他引:5  
Summary.  Network models are widely used to represent relations between interacting units or actors. Network data often exhibit transitivity, meaning that two actors that have ties to a third actor are more likely to be tied than actors that do not, homophily by attributes of the actors or dyads, and clustering. Interest often focuses on finding clusters of actors or ties, and the number of groups in the data is typically unknown. We propose a new model, the latent position cluster model , under which the probability of a tie between two actors depends on the distance between them in an unobserved Euclidean 'social space', and the actors' locations in the latent social space arise from a mixture of distributions, each corresponding to a cluster. We propose two estimation methods: a two-stage maximum likelihood method and a fully Bayesian method that uses Markov chain Monte Carlo sampling. The former is quicker and simpler, but the latter performs better. We also propose a Bayesian way of determining the number of clusters that are present by using approximate conditional Bayes factors. Our model represents transitivity, homophily by attributes and clustering simultaneously and does not require the number of clusters to be known. The model makes it easy to simulate realistic networks with clustering, which are potentially useful as inputs to models of more complex systems of which the network is part, such as epidemic models of infectious disease. We apply the model to two networks of social relations. A free software package in the R statistical language, latentnet, is available to analyse data by using the model.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号