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   148篇
  免费   8篇
管理学   15篇
民族学   4篇
人口学   6篇
丛书文集   2篇
理论方法论   23篇
综合类   1篇
社会学   92篇
统计学   13篇
  2024年   2篇
  2021年   1篇
  2020年   2篇
  2019年   10篇
  2018年   6篇
  2017年   10篇
  2016年   11篇
  2015年   5篇
  2014年   3篇
  2013年   29篇
  2012年   9篇
  2011年   6篇
  2010年   3篇
  2009年   7篇
  2008年   5篇
  2007年   6篇
  2006年   2篇
  2005年   5篇
  2004年   2篇
  2003年   2篇
  2002年   3篇
  2001年   2篇
  2000年   3篇
  1999年   5篇
  1998年   4篇
  1997年   1篇
  1996年   3篇
  1993年   1篇
  1992年   1篇
  1988年   1篇
  1987年   1篇
  1984年   1篇
  1981年   2篇
  1976年   1篇
  1975年   1篇
排序方式: 共有156条查询结果,搜索用时 15 毫秒
81.
Outside of economics, researchers have recently identified genetic predictors of “sensation-seeking” that have been linked to risky and impulsive behaviors. We examine the implications of these genetic polymorphisms for economic behavior. Our analysis indicates that the 7-repeat allele of the DRD4 gene that regulates dopamine uptake in the brain predicts risk-taking and time preferences in economic experiments that allow for ambiguity, losses and discounting. These genetic polymorphisms can also be used to directly predict financial choice patterns that are consistent with previous findings in the behavioral genetics literature.  相似文献   
82.
83.
84.
85.
对造成水分亏缺的沙土盆栽的番茄植株 (Lycopersionexcalentum Mill)设置了 3种施氮水平 ,研究其对渗透调节的影响。采用每日滴灌的方式 ,使植株保持在田间持水量水平的土壤中 ,直至胁迫发生。每处理灌溉量为 1 0 0ml,氮 0 (N0 )处理为荷格兰特 (Hoagland)培养液 ;氮 1(N1 )处理为Hoagland培养液加 60mmolNO-3 ;氮 2 (N2 )处理 :为Hoagland培养液加 1 1 0mmolNO-3 。停止灌溉 3d后 ,叶片渗透调节百分率 (叶片实际渗透势占供水良好状态下叶片渗透势的百分数 )分别为N0植株 44%,N1植株 63%,N2植株 2 9%。停止供水 8d后的百分率与之相似。在停止供水 3d后 ,对一些植株恢复每天灌溉。当胁迫解除结束时 (灌溉 8d后 ) ,叶片渗透势较低 ( - 1 .8MPa) ,在Nl中仍保持着渗透调节的状态 ( 39%) ,这与水势降低的情况下 ,膨压的保持有关。结果表明 ,N1处理可能具有增强番茄植株避脱水性和耐脱性的效应  相似文献   
86.
The paper articulates three models of collaboration between child protection services and law enforcement agencies on investigations of child maltreatment, and examines the relative impact of each model on child removals and short‐term foster care placements. An extensive review of the research literature is used to derive lessons for jurisdictions using the different models. Promising strategies from several jurisdictions are described as they relate to collaborative investigations, child removal and short‐term placements. Finally, we provide recommendations to improve child protection investigations and reduce the use of short‐term foster care placements.  相似文献   
87.
Abstract. The authors examined college student opinions of no-smoking policies, secondhand smoke, and smoking in public places. A convenience sample of 1,188 (66.4% female; 26.9% White, 64.1% Black, and 9.0% Hispanic) students attending 5 Texas colleges volunteered to complete a 60-item anonymous survey on tobacco attitudes and behaviors. Results of our study showed that women, Black students, and nonsmoking students reported the most favorable attitudes toward no smoking. Male students, white students, and students who smoked in the past 30 days (current smokers) reported the least favorable attitudes. The lowest level of agreement by all subgroups was provided for prohibiting smoking everywhere on campus (inside and outside of buildings). Implications for tobacco control on college campuses are discussed.  相似文献   
88.
89.
本文探讨了新兴城市和地区身份资本的四个关键因素,它们是资本系统方法的一部分.在这些方法中,综合资本系统(GCS)是衡量城市如何为其以知识为基础的发展而发掘能力的一种工具.本文强调GCS中身份资本的要素,以便综合差异性和透明度两方面来考察四个独特城市区域的城市身份.这些基于环境的身份似乎阐明了边缘知识城市是如何在以知识为基础的国际舞台上构建自己的身份优势的.  相似文献   
90.
Nonprofits are under increased accountability pressures to demonstrate their effectiveness. Output measurement (how much is produced) is disregarded as simplistic. Emphasis is made instead on measuring outcomes (changes in the lives of beneficiaries) or impacts (effects developed relative to the mission of the nonprofit, or the overall public good), and a growing portion of organizations state that they measure these effects. However, we question the assumption that outputs such as the number of beneficiaries served are being adequately measured. We first review existing research gaps on results measurement practices and discuss the main types of obstacles to the quality and utility of evaluation data. In this context, we argue for the need to reground nonprofit evaluation in the profound knowledge available about beneficiary populations. We discuss the potential and limitations of reach, a basic output indicator that is defined as the number of individuals directly affected by a nonprofit, and explore the organizational drivers of reach measurement. Evidence from 2,229 nonprofits shows they still lack adequate data on the beneficiaries they serve, face relevant conceptual and practical hurdles when trying to identify them, and are significantly influenced by organizational factors in their capacity to track them. Our research not only shows that nonprofits fail to adequately measure outputs, but also that measuring the number of beneficiaries served and how they are served is not as straightforward as outcome and impact advocates suggest. Practitioners and funders are reminded of the need to place beneficiaries at the core of their evaluation efforts.  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