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   4674篇
  免费   165篇
  国内免费   1篇
管理学   549篇
民族学   28篇
人口学   515篇
丛书文集   24篇
理论方法论   447篇
综合类   118篇
社会学   1938篇
统计学   1221篇
  2023年   46篇
  2022年   38篇
  2021年   56篇
  2020年   137篇
  2019年   167篇
  2018年   271篇
  2017年   270篇
  2016年   200篇
  2015年   137篇
  2014年   188篇
  2013年   907篇
  2012年   300篇
  2011年   176篇
  2010年   132篇
  2009年   124篇
  2008年   129篇
  2007年   118篇
  2006年   91篇
  2005年   75篇
  2004年   70篇
  2003年   39篇
  2002年   64篇
  2001年   68篇
  2000年   75篇
  1999年   54篇
  1998年   50篇
  1997年   47篇
  1996年   40篇
  1995年   36篇
  1994年   43篇
  1993年   35篇
  1992年   50篇
  1991年   49篇
  1990年   33篇
  1989年   31篇
  1988年   37篇
  1987年   20篇
  1986年   26篇
  1985年   37篇
  1984年   31篇
  1983年   39篇
  1982年   24篇
  1981年   23篇
  1980年   22篇
  1979年   22篇
  1978年   38篇
  1977年   18篇
  1976年   24篇
  1975年   22篇
  1974年   14篇
排序方式: 共有4840条查询结果,搜索用时 31 毫秒
101.
Complex models can only be realized a limited number of times due to large computational requirements. Methods exist for generating input parameters for model realizations including Monte Carlo simulation (MCS) and Latin hypercube sampling (LHS). Recent algorithms such as maximinLHS seek to maximize the minimum distance between model inputs in the multivariate space. A novel extension of Latin hypercube sampling (LHSMDU) for multivariate models is developed here that increases the multidimensional uniformity of the input parameters through sequential realization elimination. Correlations are considered in the LHSMDU sampling matrix using a Cholesky decomposition of the correlation matrix. Computer code implementing the proposed algorithm supplements this article. A simulation study comparing MCS, LHS, maximinLHS and LHSMDU demonstrates that increased multidimensional uniformity can significantly improve realization efficiency and that LHSMDU is effective for large multivariate problems.  相似文献   
102.
Sam V. Wass  Tim J. Smith 《Infancy》2014,19(4):352-384
Little research hitherto has examined how individual differences in attention, as assessed using standard experimental paradigms, relate to individual differences in how attention is spontaneously allocated in more naturalistic contexts. Here, we analyzed the time intervals between refoveating eye movements (fixation durations) while typically developing 11‐month‐old infants viewed a 90‐min battery ranging from complex dynamic to noncomplex static materials. The same infants also completed experimental assessments of cognitive control, psychomotor reaction times (RT), processing speed (indexed via peak look during habituation), and arousal (indexed via tonic pupil size). High test–retest reliability was found for fixation duration, across testing sessions and across types of viewing material. Increased cognitive control and increased arousal were associated with reduced variability in fixation duration. For fixations to dynamic stimuli, in which a large proportion of saccades may be exogenously cued, we found that psychomotor RT measures were most predictive of mean fixation duration; for fixations to static stimuli, in contrast, in which there is less exogenous attentional capture, we found that psychomotor RT did not predict performance, but that measures of cognitive control and arousal did. The implications of these findings for understanding the development of attentional control in naturalistic settings are discussed.  相似文献   
103.
The current study explored two possible comparison groups for the double Face‐to‐Face Still‐Face (FFSF) paradigm to evaluate their effects on infant behavior and different hypotheses about the nature of the Still‐Face (SF) effect, an effect not fully understood. Mothers and their 4‐month‐old infants were randomly assigned to one of three groups, a double FFSF group (GroupFFSF, n = 44), a control, semi‐structured play group (GroupStory, n = 46), or a control, unstructured play group (GroupPlay, n = 28). As hypothesized, GroupFFSF infants exhibited the classic SF response (decreased positive affect and gaze to mother; increased negative affect) and GroupPlay infants showed an increase in negative affect over episodes. Contrary to expectations, GroupStory infants displayed a similar, but less intense, pattern of behavior as GroupFFSF. Taken together, the findings indicate that multiple episodes of face‐to‐face play exceeded 4‐month‐olds' regulatory capacities and that infants are sensitive to shared communicative intentions and violations of social expectations, whether these violations are negative or positive in nature.  相似文献   
104.
In therapeutic conversations, questions can be considered as interventions in their own right. This study is a cross‐cultural replication of Grant (Journal of Systemic Therapies, 2012, 31, 2, 21) study on the effects of different types of questions on various clinically relevant variables. A total of 204 students of a Spanish university described a real‐life problem that they wanted to solve and were then randomly assigned to either a solution‐focused or a problem‐focused questions condition. Before and after answering the questions, they completed a set of measures that assessed positive and negative affect, self‐efficacy, and goal attainment. Solution‐focused questions produced a significantly greater increase in self‐efficacy, goal approach, and action steps than problem‐focused questions, and a significantly greater decrease in negative affect, providing further empirical support to solution‐focused practices.  相似文献   
105.
Intergenerational transmission has been successfully employed in economic research to explain the persistence of certain economic behaviors across generations. This paper evaluates the relevance of this transmission process in the formation of gender roles during childhood. In particular, we analyze the relationship between parents?? and children??s housework allocation patterns. We propose a simple theoretical model that predicts that parents with a strong adherence to gender to traditional gender norms??as proxied by their division of household labor??are more likely to allocate housework to children in a way that reflects stereotypes of men??s and women??s domestic tasks. The empirical application is carried out with data from the 2002?C2003 Spanish Time Use Survey. The sample restricts to two-parent households with at least one child aged 10?C17?years. We find a significant positive correlation between a more egalitarian parents?? allocation of housework and a less asymmetrical distribution of domestic chores between sons and daughters.  相似文献   
106.
The objective of this study is to analyze the aspects that allowed a critical part of Social Economy Organizations (SEOs) to survive a recession period, especially participation in collaborative networks. The financial stress of an SEO will depend on the resources and capabilities available to the organization. To analyze the financial stress of Spanish SEOs, we defined a sample of 714 SEOs. Approximately half of these organizations suffered from financial stress in the analyzed period (2009–2012). The results obtained in this study reveal the existence of three factors that distinguish organizations under financial stress: (a) a high dependence on government funding; (b) changes in the relationship between staff and volunteers; and (c) a lack of access to markets. The combination of these three elements results in an unsustainable situation for the organization. The development of a collaborative profile increases the SEO’s probability of surviving the adverse manifestations of its environment.  相似文献   
107.
Previous studies suggest significant differences between navigating virtual environments in a life-like walking manner (i.e., using treadmills or walk-in-place techniques) and virtual navigation (i.e., flying while really standing). The latter option, which usually involves hand-centric devices (e.g., joysticks), is the most common in Virtual Reality-based studies, mostly due to low costs, less space and technology demands. However, recently, new interaction devices, originally conceived for videogames have become available offering interesting potentialities for research. This study aimed to explore the potentialities of the Nintendo Wii Balance Board as a navigation interface in a Virtual Environment presented in an immersive Virtual Reality system. Comparing participants' performance while engaged in a simulated emergency egress allows determining the adequacy of such alternative navigation interface on the basis of empirical results. Forty university students participated in this study. Results show that participants were more efficient when performing navigation tasks using the Joystick than with the Balance Board. However there were no significantly differences in the behavioral compliance with exit signs. Therefore, this study suggests that, at least for tasks similar to the studied, the Balance Board have good potentiality to be used as a navigation interface for Virtual Reality systems.  相似文献   
108.
In Russia, elder abuse is rarely discussed in the professional literature and the media. However, it is posited that parricide can be considered a form of elder abuse in Russia, as the line between elder abuse and parricide can be vague. Instances of parricide can appear trivial, hardly realized as such by victims and the social environment. Borderline cases can include involving older people in binge drinking, denying them help, and manipulating them to commit suicide. The perpetrators are often nonpsychotic, although sometimes exhibiting abnormal personality traits. Anger toward the victim can be absent on the part of the perpetrator, with their actions often driven by economic desires. A concluding point is that for better prevention of parricide and, therefore, elder abuse, it should not be considered only an unusual horrific crime committed by the mentally ill.  相似文献   
109.
The ergonomic risks constitute a vital aspect of study and prevention for the worker's health, especially for people with different capacities. Very job has and implies certain type of risk for the worker's health, depending on the conditions it is done with the use of tools or without them. Aplicated techniques: posturogram, baropodometry, Schober test, biocinemátic chain test, Fukuda test, propioceptiva plataform in personnel with special capabilities.  相似文献   
110.
Same parliaments, to form a committee of size $q$ , use a voting process like the following: every parliamentary member votes for one out of a fixed set of candidates, and those $q$ candidates receiving more votes are elected for the committee. Assuming total discipline of vote, this is a game form in which players are the parliamentary groups. We investigate, according to some natural hypotheses about preferences, the likely distribution of the members of this committee. The main results are: (a) when fractional votes are allowed, there is a complete agreement between the distribution among the groups of the elected candidates that are outcomes of a Nash equilibrium and the distribution that, according to the size of the groups, would compute the Jefferson-d’Hondt allocation rule, and (b) when fractional votes are not allowed, there is a near agreement for a majority of situations.  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