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   5256篇
  免费   131篇
  国内免费   55篇
管理学   416篇
民族学   10篇
人才学   6篇
人口学   26篇
丛书文集   352篇
理论方法论   59篇
综合类   3140篇
社会学   221篇
统计学   1212篇
  2024年   8篇
  2023年   45篇
  2022年   17篇
  2021年   59篇
  2020年   72篇
  2019年   84篇
  2018年   120篇
  2017年   168篇
  2016年   105篇
  2015年   154篇
  2014年   246篇
  2013年   653篇
  2012年   328篇
  2011年   368篇
  2010年   289篇
  2009年   301篇
  2008年   313篇
  2007年   323篇
  2006年   286篇
  2005年   290篇
  2004年   216篇
  2003年   223篇
  2002年   199篇
  2001年   161篇
  2000年   106篇
  1999年   54篇
  1998年   32篇
  1997年   34篇
  1996年   22篇
  1995年   15篇
  1994年   21篇
  1993年   14篇
  1992年   15篇
  1991年   10篇
  1990年   10篇
  1989年   9篇
  1988年   6篇
  1987年   11篇
  1986年   3篇
  1985年   15篇
  1984年   15篇
  1983年   7篇
  1982年   7篇
  1980年   2篇
  1979年   2篇
  1977年   4篇
排序方式: 共有5442条查询结果,搜索用时 15 毫秒
201.
There is considerable debate surrounding the choice of methods to estimate information fraction for futility monitoring in a randomized non-inferiority maximum duration trial. This question was motivated by a pediatric oncology study that aimed to establish non-inferiority for two primary outcomes. While non-inferiority was determined for one outcome, the futility monitoring of the other outcome failed to stop the trial early, despite accumulating evidence of inferiority. For a one-sided trial design for which the intervention is inferior to the standard therapy, futility monitoring should provide the opportunity to terminate the trial early. Our research focuses on the Total Control Only (TCO) method, which is defined as a ratio of observed events to total events exclusively within the standard treatment regimen. We investigate its properties in stopping a trial early in favor of inferiority. Simulation results comparing the TCO method with alternative methods, one based on the assumption of an inferior treatment effect (TH0), and the other based on a specified hypothesis of a non-inferior treatment effect (THA), were provided under various pediatric oncology trial design settings. The TCO method is the only method that provides unbiased information fraction estimates regardless of the hypothesis assumptions and exhibits a good power and a comparable type I error rate at each interim analysis compared to other methods. Although none of the methods is uniformly superior on all criteria, the TCO method possesses favorable characteristics, making it a compelling choice for estimating the information fraction when the aim is to reduce cancer treatment-related adverse outcomes.  相似文献   
202.
Compared with most of the existing phase I designs, the recently proposed calibration-free odds (CFO) design has been demonstrated to be robust, model-free, and easy to use in practice. However, the original CFO design cannot handle late-onset toxicities, which have been commonly encountered in phase I oncology dose-finding trials with targeted agents or immunotherapies. To account for late-onset outcomes, we extend the CFO design to its time-to-event (TITE) version, which inherits the calibration-free and model-free properties. One salient feature of CFO-type designs is to adopt game theory by competing three doses at a time, including the current dose and the two neighboring doses, while interval-based designs only use the data at the current dose and is thus less efficient. We conduct comprehensive numerical studies for the TITE-CFO design under both fixed and randomly generated scenarios. TITE-CFO shows robust and efficient performances compared with interval-based and model-based counterparts. As a conclusion, the TITE-CFO design provides robust, efficient, and easy-to-use alternatives for phase I trials when the toxicity outcome is late-onset.  相似文献   
203.
Scholars have called for communication research to verify the causal claims of mediation models from a research design perspective, instead of only proving mediation statistically. This study validates whether and how anger mediates the causal effects of crisis types on publics’ responses in Situational Crisis Communication Theory (SCCT), including reputation, negative word-of-mouth intention, and purchase intention in China. Two experiments were conducted based on the experimental-causal-chain design. Results in Study 1 demonstrate that the causal relationships between three crisis types and publics’ emotional and other responses in China are consistent with findings in Western contexts. In Study 2, the results of a 2 (anger: low, high) x 3 (crisis types: victim crisis, accidental crisis, preventable crisis) factorial experiment reveal significant mediating effects of anger on publics’ responses in the victim and accidental crisis conditions, but not for preventable crises. This novel finding suggests the possibility of a threshold effect of anger in the mediating process. Specifically, anger has a mediating effect on publics’ responses when it is below the high-anger threshold. However, anger may no longer be the mediator when it exceeds this threshold. This finding empirically challenges the common assumption that emotions have a linear relationship with publics’ responses, thus offering a new research avenue and deeper understanding of how emotions function in crises. Therefore, this research serves as a pioneer, calling for future studies to validate other theories involving mediation to yield fruitful insights.  相似文献   
204.
The Narrative Policy Framework has a growing number of researchers seeking to apply the framework in policy process scholarship. This article is intended to assist those interested in conducting an NPF study that is ‘clear enough to be wrong’ (Sabatier, 2000). While graduate programs offer critical methodological training, this article focuses on the specific application of the NPF to research inquiries about the role of policy narratives in the policy process. We approach our discussion by examining various decisions in the research process and include a detailed discussion of specifying the model and obtaining narrative data. We also point out areas for further investigation.  相似文献   
205.
The present study uses the concept of technological efficacy derived from ecological psychology and design studies to offer an alternative way of analyzing how policy instruments affect change. Reasoning from this, the paper outlines a framework for analyzing policy instruments in terms of their affordances. We define affordances as the means through which an instrument exerts influence on its intended target audience. Using this approach, we contend that policy instruments may be analyzed as interfaces that organize social relations and create structures of opportunity and/or restrict possibilities for action. We argue that explicating the pathways through which instruments afford or constrain action is a central task for policy analysis. Our proposed framework of analysis builds on the idea that instruments yield effects by facilitating action and learning. We further contend that the actions that an instrument can facilitate or inhibit are determined by specific affordance modalities of the instrument in conjunction with contingencies of the actor and the policy environment. Examples from research policy are used to illustrate some of these effects.  相似文献   
206.
Organized activities represent a potentially important context for the development of adolescent sociopolitical values, but few studies have examined longitudinal associations between youths’ sociopolitical values and activity involvement. Adolescents (N = 299, Time 1 Mage = 15.49, SD = .93, 62% female) reported on their organized activity involvement (volunteering, church, sports, arts/music, school and community clubs) and sociopolitical values (materialism, social dominance, authoritarianism, patriotism, spirituality) at baseline and one year later. Greater involvement in arts/music predicted lower spirituality and patriotism one year later and greater involvement in church predicted higher levels of spirituality and lower levels of social dominance one year later. Higher levels of materialism predicted less involvement in arts/music one year later and higher social dominance values predicted less involvement in volunteering one year later. Findings support the importance of organized activities in sociopolitical development, and suggest that sociopolitical values may guide decisions concerning future organized activity involvement.  相似文献   
207.
谭锦绣  邹莉 《职业时空》2012,(4):137-138,141
为了增强大学新生班级凝聚力,促进学生合作意识的培养,以马斯洛的需要层次理论、人际关系理论、社会心理学理论和团体心理咨询理论为指导,设计了大学新生班级凝聚力团体心理辅导方案,包括理念、目标、设置、具体方案设计、活动效果评价反馈和活动亮点展示几部分。  相似文献   
208.
Economic issues linked to career counseling are a cause for concern to policy makers in developed countries because they expect career practitioners to provide evidence of the efficiency of career counseling interventions. The aim of this study was to test an individual evaluation method mixing time series (outcomes) and life narrative (processes). The method used 5 items related to 1 client's career decision self‐efficacy and studied the evolution of those items throughout the intervention of 1 career counselor (43 days). Changepoint analysis helped in identifying the changes that have to be taken into account for time series and which are contextualized in the client's verbatim analysis. This mixed method highlighted that the career counselor's intervention increased the client's career decision self‐efficacy. Practitioners could use the methodology proposed in this article to evaluate their interventions. They could also report their practice to clients, employers, and decision makers.  相似文献   
209.
There is an increasing demand for affordable multifamily housing for a rapidly growing population of ethnic elders. Using the lived experiences of Korean American elders currently residing in affordable housing in the Midwest as one such example, this study seeks to develop design guidelines to meet the specific living needs and desires of this aging population. Verified against well-established building standards and accepted guidelines, these design recommendations lay the groundwork for multifamily housing that will assist elders to age in place in safer, healthier and happier environments.  相似文献   
210.
The evaluation of classroom-based educational interventions is fraught with tensions, the most critical of which is choosing between focusing the inquiry on measuring the effects of treatment or in proximately utilizing the data to improve practice. This paper attempted to achieve both goals through the use of intervention-oriented evaluation of a professional development program intended to diagnose and correct students’ misconceptions of climate change. Data was gathered, monitored and analyzed in three stages of a time-series design: the baseline, treatment and follow-up stages. The evaluation itself was the ‘intervention’ such that the data was allowed to ‘contaminate’ the treatment. This was achieved through giving the teacher unimpeded access to the collected information and to introduce midcourse corrections as she saw fit to her instruction. Results showed a significant development in students’ conceptual understanding only after the teacher's decision to use direct and explicit refutation of misconceptions. Due to the accessibility of feedback, it was possible to locate specifically at which point in the process that the intervention was most effective. The efficacy of the intervention was then measured through comparing the scores across the three research stages. The inclusion of a comparison group to the design is recommended for future studies.  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