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   29380篇
  免费   598篇
  国内免费   1篇
管理学   4053篇
民族学   195篇
人口学   3957篇
丛书文集   75篇
教育普及   1篇
理论方法论   2222篇
综合类   458篇
社会学   14080篇
统计学   4938篇
  2023年   131篇
  2022年   77篇
  2021年   133篇
  2020年   347篇
  2019年   517篇
  2018年   2171篇
  2017年   2358篇
  2016年   1587篇
  2015年   442篇
  2014年   602篇
  2013年   3549篇
  2012年   1040篇
  2011年   1736篇
  2010年   1490篇
  2009年   1156篇
  2008年   1307篇
  2007年   1435篇
  2006年   523篇
  2005年   621篇
  2004年   663篇
  2003年   558篇
  2002年   451篇
  2001年   473篇
  2000年   423篇
  1999年   407篇
  1998年   311篇
  1997年   261篇
  1996年   307篇
  1995年   291篇
  1994年   247篇
  1993年   258篇
  1992年   301篇
  1991年   294篇
  1990年   289篇
  1989年   255篇
  1988年   250篇
  1987年   201篇
  1986年   231篇
  1985年   251篇
  1984年   216篇
  1983年   191篇
  1982年   160篇
  1981年   130篇
  1980年   156篇
  1979年   171篇
  1978年   134篇
  1977年   115篇
  1976年   88篇
  1975年   91篇
  1974年   93篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
951.
The present research examined how school contexts shape the extent to which beliefs about the potential for change (implicit theories) interact with social adversity to predict depressive symptoms. A preregistered multilevel regression analysis using data from 6,237 ninth‐grade adolescents in 25 U.S. high schools showed a three‐way interaction: Implicit theories moderated the associations between victimization and depressive symptoms only in schools with high levels of school‐level victimization, but not in schools with low victimization levels. In high‐victimization schools, adolescents who believed that people cannot change (an entity theory of personality) were more depressed when they were victimized more frequently. Thus, the mental health correlates of adolescents’ implicit theories depend on both personal experiences and the norms in the context.  相似文献   
952.
Urban Ecosystems - Critical resources for birds nesting in cities can support populations in spite of the challenges imposed by urbanization, and the identification of such resources can shed light...  相似文献   
953.
In the U.S., decisions regarding social control are increasingly modeled on two dominant institutions: the criminal justice and medical/healthcare systems. Sociologists and other scholars refer to this adoption of legal and/or medical terminology and technologies as criminalization and medicalization. These models of social control are particular evident in how America defines and manages child behavior. Public schools borrow from both the criminal justice and medical systems as part of the routine educational setting. In this article, I provide the first synthesis and review of the school criminalization and medicalization literatures. In doing so, I argue that criminalized school social controls provide harsh, repressive responses to student misbehavior, while medicalized school social controls provide rehabilitative and restitutive responses. Given these fundamentally different approaches to student behavior, I argue that the disproportionate use of criminalized and medicalized social control across racial/ethnic groups and children from different socioeconomic backgrounds entrenches inequalities and functions to channel racial/ethnic minorities and poor children into the school‐to‐prison pipeline while keeping socially advantaged children in school and away from the problems associated with criminalized social control.  相似文献   
954.
The purpose of this study is to highlight the application of sparse logistic regression models in dealing with prediction of tumour pathological subtypes based on lung cancer patients'' genomic information. We consider sparse logistic regression models to deal with the high dimensionality and correlation between genomic regions. In a hierarchical likelihood (HL) method, it is assumed that the random effects follow a normal distribution and its variance is assumed to follow a gamma distribution. This formulation considers ridge and lasso penalties as special cases. We extend the HL penalty to include a ridge penalty (called ‘HLnet’) in a similar principle of the elastic net penalty, which is constructed from lasso penalty. The results indicate that the HL penalty creates more sparse estimates than lasso penalty with comparable prediction performance, while HLnet and elastic net penalties have the best prediction performance in real data. We illustrate the methods in a lung cancer study.  相似文献   
955.
To perform variable selection in expectile regression, we introduce the elastic-net penalty into expectile regression and propose an elastic-net penalized expectile regression (ER-EN) model. We then adopt the semismooth Newton coordinate descent (SNCD) algorithm to solve the proposed ER-EN model in high-dimensional settings. The advantages of ER-EN model are illustrated via extensive Monte Carlo simulations. The numerical results show that the ER-EN model outperforms the elastic-net penalized least squares regression (LSR-EN), the elastic-net penalized Huber regression (HR-EN), the elastic-net penalized quantile regression (QR-EN) and conventional expectile regression (ER) in terms of variable selection and predictive ability, especially for asymmetric distributions. We also apply the ER-EN model to two real-world applications: relative location of CT slices on the axial axis and metabolism of tacrolimus (Tac) drug. Empirical results also demonstrate the superiority of the ER-EN model.  相似文献   
956.
Whatever the theoretical merits of an industrial policy, in practice state incentives in support of infant industry are difficult to withdraw once they have been granted. Infant maturation is thereby delayed, resulting in ‘policy capture’ which confers rents on the assisted firms at the expense of consumers and/or taxpayers. The process is well-documented in poorly managed economies pursuing autarkic industrial policies (Auty, 1994a). This article examines evidence of policy capture in well-managed economies pursuing competitive industrial policies. Examples are drawn from the heavy (and chemical) industry drives of South Korea (hereafter Korea) and Taiwan, but the research is first set in the context of the industrial policy debate.  相似文献   
957.
Jung's personality-theory typology is used as a framework for exploring the effects of cognitive style on the type and radicalness of choices made in strategic decision situations. Extending the work of Haley and Stumpf [23], it is proposed that individuals with different personality-type preferences exhibit cognitive styles that are associated with specific biases in the pattern of choices they make. Through participation in an interactive behavioral simulation, 407 participants confronted over one hundred ill-structured decision situations and proposed whatever actions they perceived appropriate. The results support the hypothesized relationships that individuals with different personality-type preferences (i.e., sensing-thinking, intuition-thinking, sensing-feeling, and intuition-feeling) take patterns of actions that reflect specific biases (i.e., selective perception, positivity, social desirability, and reasoning-by-analogy, respectively). The implications of these findings for evaluating the likely effectiveness of strategic decisions and making senior-level staffing decisions are discussed.  相似文献   
958.
In a recent article, Chatterjee and Greenwood [1] addressed the problem of multicollinearity in polynomial regression models. They noted that there is a high correlation between X and X2; therefore, a second-order polynomial model suffers the consequences of collinearity. Chatterjee and Greenwood [1] suggested a method they believe will overcome the problem. The contention of the present comment is that the suggested method accomplishes nothing and, indeed, has the potential to lead the unwary researcher to the wrong inference and misinterpretation of his results.  相似文献   
959.
In an earlier issue of Decision Sciences, Jesse, Mitra, and Cox [1] examined the impact of inflationary conditions on the economic order quantity (EOQ) formula. Specifically, the authors analyzed the effect of inflation on order quantity decisions by means of a model that takes into account both inflationary trends and time discounting (over an infinite time horizon). In their analysis, the authors utilized two models: Current-dollars model and Constant-dollars model. These models were derived, of course, by setting up a total cost equation in the usual manner then finding the optimum order quantity that minimizes the total cost. Jesse, Mitra, and Cox [1] found that EOQ is approximately the same under both conditions; with or without inflation. However, we disagree with the conclusion drawn by [2] and show that EOQ will be different under inflationary conditions, provided that the inflationary conditions are properly accounted for in the formulation of the total cost model.  相似文献   
960.
Practitioners and researchers have long been interested in achieving the highest response rate within resource constraints on their mailed surveys. Achieving this high response rate typically has required the selection of the right mix of response-facilitating techniques. The selection decisions were generally made under the assumption that the response-facilitating techniques act independently of one another. The authors have examined the validity of this independence assumption by identifying the major response facilitators in use and then analyzing the results of 531 independent mail survey studies. The authors conclude that major facilitators do not function independently. In fact, it was found that significant joint action interactive effects on response rates do exist. Practitioners and researchers who are faced with the survey design decisions of choosing response facilitators can receive assistance by reviewing the results of this diverse collection of reported experiences.  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