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   2327篇
  免费   19篇
管理学   231篇
民族学   19篇
人口学   290篇
丛书文集   7篇
理论方法论   190篇
综合类   29篇
社会学   1177篇
统计学   403篇
  2023年   14篇
  2021年   13篇
  2020年   48篇
  2019年   67篇
  2018年   85篇
  2017年   117篇
  2016年   101篇
  2015年   54篇
  2014年   71篇
  2013年   446篇
  2012年   62篇
  2011年   84篇
  2010年   57篇
  2009年   43篇
  2008年   70篇
  2007年   67篇
  2006年   40篇
  2005年   49篇
  2004年   52篇
  2003年   37篇
  2002年   54篇
  2001年   50篇
  2000年   40篇
  1999年   31篇
  1998年   31篇
  1997年   25篇
  1996年   20篇
  1995年   28篇
  1994年   27篇
  1993年   24篇
  1992年   27篇
  1991年   26篇
  1990年   18篇
  1989年   20篇
  1988年   27篇
  1987年   24篇
  1986年   18篇
  1985年   21篇
  1984年   17篇
  1983年   16篇
  1982年   13篇
  1981年   16篇
  1980年   12篇
  1979年   16篇
  1978年   21篇
  1977年   16篇
  1976年   15篇
  1975年   16篇
  1970年   11篇
  1968年   12篇
排序方式: 共有2346条查询结果,搜索用时 0 毫秒
41.
ABSTRACT

With the rapid growth in incarceration in the United States over the past few decades came dramatic growth in the number of the incarcerated parents with at least one minor child. Parental incarceration places extra stresses and strains on families and children. Almost all of those incarcerated will eventually be released. However, the majority of those released from prison will be rearrested within a year. Finding interventions that can decrease the likelihood of returning to crime and to incarceration are of utmost importance. Using a social bond theory framework, the authors examine the moderating effect of living with a child before incarceration on program outcomes related to a prison-based parent management training program. A significant effect was found. Implications for these findings are discussed for future research and practice.  相似文献   
42.

Background

A low urine pH is a characteristic metabolic feature of metabolic syndrome and type 2 diabetes. The purpose of the current study was to investigate the effects of a 12-week home-based bench step exercise on the urine pH status of elderly female subjects.

Methods

The current study is a secondary analysis of a randomized controlled trial (RCT) in which 59 postmenopausal female subjects were randomized to either the exercise group (n?=?29) or the control group (n?=?30). The subjects in the exercise group were instructed to perform home-based exercises using a bench step at the anaerobic threshold (AT), with a goal of performing ≥140 min/week at home for 12 weeks. The subjects in the control group were instructed to not change their normal lifestyle. Urine was collected after overnight fasting, and the urine pH was measured using a urinary test strip. The inter-group-differences at baseline and the pre-post changes within groups were assessed using the Mann-Whitney U test and Wilcoxon’s signed-rank test, respectively. Additionally, the difference in the post-intervention urine pH levels of the two groups, adjusted for the pre-intervention values (the estimated effect size) and the precision (95% confidence intervals) were investigated using an analysis of covariance.

Results

The pre-post comparison of the urine pH data using Wilcoxon’s signed-rank test showed a significant increase in the urine pH levels of the exercise group (p?<?0.05); there was no significant change in the urine pH levels of the control group. However, the estimated effect size (0.15) was small and the confidence interval straddled 0 (?0.25–0.55).

Conclusions

Based on the results of the current secondary analysis of an RCT, we could not clearly conclude that exercise has a beneficial effect on the urine pH. Further well-designed RCTs should be conducted to determine whether aerobic exercise is truly able to ameliorate urine acidification.

Trial registration

The study was retrospectively registered in the University Hospital Medical Information Network (UMIN) as “Effect of step exercise on aerobic fitness and progression of atherosclerosis in the elderly” under the registration number UMIN 000026743 (the date of registration: March 28, 2017).
  相似文献   
43.
This paper presents a small-scale qualitative case study of five women’s experiences of leadership roles in Irish media industries. Relational Leadership Theory is used to examine whether there is a gendered dimension to women’s leadership and to explore why women’s participation in leadership has not resulted in significant feminist gains or changes to media organisations. The article finds that: the women saw their leadership as relational and simultaneously as socially constructed in a gendered manner. Moreover, the women led organisational change towards greater gender equality in the norms of media work. However, while the women’s leadership was relational and feminine, it was not necessarily feminist; it did not aim to generate systemic changes within the gendering of the media as an institution. The changes that the women wrought incorporated women into a system of production that remained nonetheless masculinist.  相似文献   
44.
This study uses hazard function estimations and time‐series and cross‐sectional growth regressions to examine the impact of exit through merger and acquisition (M&A) or failure, and internally generated growth, on the firm‐size distribution within the U.S. credit union sector. Consolidation through M&A was the principal cause of a reduction in the number of credit unions, but impact on concentration was small. Divergence between the average internally generated growth of smaller and larger credit unions was the principal driver of the rise in concentration. (JEL G21)  相似文献   
45.
This essay examines the relationship between transnational non-governmental organizations (NGOs) and postcolonial disasters as represented in literature. After the 1990s expansion of humanitarian organizations, a wide array of NGO-related literature emerges, including depictions of aid workers in fiction as well as humanitarian-authored narratives. While these texts contain a capacity for self-critique typically lacking in transnational NGO campaign materials, they remain mired in a ‘bureaucratic imagination’, sequestered from supposed beneficiaries. Alongside this literary development is an increasing pressure on postcolonial fiction to align with narrowly defined NGO missions, or what might be called an ‘NGO-ization of postcolonial narrative’. This essay interprets Indra Sinha’s Animal’s People as a vociferous refutation of such humanitarian pressure. Sinha stages the interaction between subaltern survivor and humanitarian benefactor not in terms of heroic salvation or radical rejection but as a conditional and negotiated solidarity. Disaster thus creates an opportunity to reimagine the subaltern-humanitarian relationship.  相似文献   
46.
Multiple deployments, a prominent characteristic of operations Enduring Freedom, Iraqi Freedom, and New Dawn, have been linked to increased risk for various mental health conditions. It is also well known that military transitions, such as a change of duty station or discharge, are an inevitable part of military life. While military transitions can be stressful for any service member or veteran, those with mental health conditions face additional challenges. Transition stress can exacerbate a mental health condition that in turn hinders ability to manage the transition, resulting in a cycle of stress. As a result, those receiving mental health care while transitioning often experience difficulty continuing treatment post-transition. This article describes a unique and innovative transition coaching program designed to address this emerging issue.  相似文献   
47.
48.
A set S of vertices of a graph G is a total outer-connected dominating set if every vertex in V(G) is adjacent to some vertex in S and the subgraph induced by V?S is connected. The total outer-connected domination number γ toc (G) is the minimum size of such a set. We give some properties and bounds for γ toc in general graphs and in trees. For graphs of order n, diameter 2 and minimum degree at least 3, we show that $\gamma_{toc}(G)\le \frac{2n-2}{3}$ and we determine the extremal graphs.  相似文献   
49.
Many large organizations use a stage‐gate process to manage new product development projects. In a typical stage‐gate process project managers learn about potential ideas from research and exert effort in development while senior executives make intervening go/no‐go decisions. This decentralized decision making results in an agency problem because the idea quality in early stages is unknown to the executive and the project manager must exert unobservable development effort in later stages. In light of these challenges, how should the firm structure incentives to ensure that project managers reveal relevant information and invest the appropriate effort to create value? In this study, we develop a model of adverse selection in research and moral hazard in development with a go/no‐go decision at the intervening gate. Our results show that the principal's uncertainty regarding early‐stage idea quality—a term we refer to as idea risk—alters the effect of late‐stage development risk. The presence of idea risk can alter the incentives offered to the agent and may lead the principal to reject projects that otherwise seem favorable in terms of positive net present value. A simulation of early‐stage ideas, found through search on a complex landscape, shows that the firm can mitigate the negative effects of idea risk by encouraging breadth of search and high tolerance for failure.  相似文献   
50.
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