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   1287篇
  免费   51篇
管理学   157篇
民族学   8篇
人口学   108篇
丛书文集   11篇
理论方法论   143篇
综合类   20篇
社会学   653篇
统计学   238篇
  2023年   4篇
  2022年   4篇
  2021年   7篇
  2020年   15篇
  2019年   24篇
  2018年   35篇
  2017年   24篇
  2016年   28篇
  2015年   34篇
  2014年   36篇
  2013年   187篇
  2012年   45篇
  2011年   47篇
  2010年   33篇
  2009年   35篇
  2008年   44篇
  2007年   47篇
  2006年   45篇
  2005年   45篇
  2004年   59篇
  2003年   26篇
  2002年   36篇
  2001年   31篇
  2000年   36篇
  1999年   30篇
  1998年   18篇
  1997年   23篇
  1996年   26篇
  1995年   19篇
  1994年   16篇
  1993年   8篇
  1992年   20篇
  1991年   24篇
  1990年   23篇
  1989年   19篇
  1988年   15篇
  1987年   7篇
  1986年   11篇
  1985年   13篇
  1984年   22篇
  1983年   15篇
  1982年   18篇
  1981年   17篇
  1980年   10篇
  1979年   11篇
  1978年   9篇
  1977年   6篇
  1976年   5篇
  1975年   6篇
  1973年   7篇
排序方式: 共有1338条查询结果,搜索用时 171 毫秒
31.
Penicillin and ampicillin drugs are approved for use in food animals in the United States to treat, control, and prevent diseases, and penicillin is approved for use to improve growth rates in pigs and poultry. This article considers the possibility that such uses might increase the incidence of ampicillin-resistant Enterococcus faecium (AREF) of animal origin in human infections, leading to increased hospitalization and mortality due to reduced response to ampicillin or penicillin. We assess the risks from continued use of penicillin-based drugs in food animals in the United States, using several assumptions to overcome current scientific uncertainties and data gaps. Multiplying the total at-risk population of intensive care unit (ICU) patients by a series of estimated factors suggests that not more than 0.04 excess mortalities per year (under conservative assumptions) to 0.14 excess mortalities per year (under very conservative assumptions) might be prevented in the whole U.S. population if current use of penicillin drugs in food animals were discontinued and if this successfully reduced the prevalence of AREF infections among ICU patients. These calculations suggest that current penicillin usage in food animals in the United States presents very low (possibly zero) human health risks.  相似文献   
32.
33.
OBJECTIVE: To preliminarily evaluate telephone-delivered motivational enhancement therapy (MET) in motivating unadjudicated and nontreatment seeking intimate partner violence (IPV) perpetrators, who also use substances, to self-refer into treatment. METHOD: 124 adult men were recruited via a multimedia marketing campaign and were randomly assigned to the intervention (MET) or comparison group following a baseline assessment. Participants in the MET condition received a personalized feedback report on their IPV and substance-use behaviors, consequences, and social norms beliefs. RESULTS: Results supported the likely effectiveness of MET in short-term reduction of IPV behavior, increasing motivation for treatment seeking, and changing perceived norms for IPV and substance abuse (SA). CONCLUSIONS: Applications for brief MET interventions to facilitate voluntary treatment entry among substance-using IPV perpetrators are discussed.  相似文献   
34.
We argue that poverty can perpetuate itself by undermining the capacity for self‐control. In line with a distinguished psychological literature, we consider modes of self‐control that involve the self‐imposed use of contingent punishments and rewards. We study settings in which consumers with quasi‐hyperbolic preferences confront an otherwise standard intertemporal allocation problem with credit constraints. Our main result demonstrates that low initial assets can limit self‐control, trapping people in poverty, while individuals with high initial assets can accumulate indefinitely. Thus, even temporary policies that initiate accumulation among the poor may be effective. We examine implications concerning the effect of access to credit on saving, the demand for commitment devices, the design of financial accounts to promote accumulation, and the variation of the marginal propensity to consume across income from different sources. We also explore the nature of optimal self‐control, demonstrating that it has a simple and behaviorally plausible structure that is immune to self‐renegotiation.  相似文献   
35.
This work concerns itself with the debate taking place in the United States about the duty of care financial advisers owe investors. On one side it is argued that advisers need only concern themselves with recommendations which meet certain suitability standards. On the other side, there are those who argue the suitability standard is not strong enough to adequately protect investor interests. Instead of ensuring investment recommendations are merely suitable, financial advisers owe their investors a fiduciary duty to “act in the best interest of the customer without regard to the financial or other interests … of the investment adviser providing the advice.” (SEC, 2011). In applying a properly understood conception of what fiduciary means I argue that regulations should not be harmonized but that fiduciary duty should apply to all who provide personalized investment advice to retail customers. I will further argue that even if the regulations are harmonized as proposed, because of exemptions for broker‐dealers as envisioned in the proposal, and which currently apply to Registered Investment Advisers, the efficacy of fiduciary duty is diluted to the point of rendering its current application, much less its potential uniform imposition, irrelevant.  相似文献   
36.
Process regression methodology is underdeveloped relative to the frequency with which pertinent data arise. In this article, the response-190 is a binary indicator process representing the joint event of being alive and remaining in a specific state. The process is indexed by time (e.g., time since diagnosis) and observed continuously. Data of this sort occur frequently in the study of chronic disease. A general area of application involves a recurrent event with non-negligible duration (e.g., hospitalization and associated length of hospital stay) and subject to a terminating event (e.g., death). We propose a semiparametric multiplicative model for the process version of the probability of being alive and in the (transient) state of interest. Under the proposed methods, the regression parameter is estimated through a procedure that does not require estimating the baseline probability. Unlike the majority of process regression methods, the proposed methods accommodate multiple sources of censoring. In particular, we derive a computationally convenient variant of inverse probability of censoring weighting based on the additive hazards model. We show that the regression parameter estimator is asymptotically normal, and that the baseline probability function estimator converges to a Gaussian process. Simulations demonstrate that our estimators have good finite sample performance. We apply our method to national end-stage liver disease data. The Canadian Journal of Statistics 48: 222–237; 2020 © 2019 Statistical Society of Canada  相似文献   
37.
Two studies examined the relationships among injunctive norms and college student gambling. In study 1 we evaluated the accuracy of perceptions of other students’ approval of gambling and the relationship between perceived approval and gambling behavior. In study 2 we evaluated gambling behavior as a function of perceptions of approval of other students, friends, and family. In study 1, which included 2524 college students, perceptions of other students’ approval of gambling were found to be overestimated and were negatively associated with gambling behavior. The results of study 2, which included 565 college students, replicated the findings of study 1 and revealed positive associations between gambling behavior and perceived approval of friends and family. Results highlight the complexity of injunctive norms and the importance of considering the reference group (e.g., peers, friends, family members) in their evaluation. Results also encourage caution in considering the incorporation of injunctive norms in prevention and intervention approaches.  相似文献   
38.
This article discusses the life course perspective on drug use, including conceptual and analytic issues involved in developing the life course framework to explain how drug use trajectories develop during an individual's lifetime and how this knowledge can guide new research and approaches to management of drug dependence. Central concepts include trajectories marked by transitions and social capital and turning points influencing changes. The life course perspective offers an organizing framework for classifying varying drug use trajectories, identifying critical events and factors contributing to the persistence or change in drug use, analytically ordering events that occur during the life span, and determining contributory relationships.  相似文献   
39.
Relocation stress syndrome is a nursing diagnosis characterized by symptoms such as anxiety, confusion, hopelessness, and loneliness. It usually occurs in older adults shortly after moving from a private residence to a nursing home or assisted-living facility. The primary purpose of this study was to validate the symptoms of relocation stress syndrome. Eight nursing home residents and 8 assisted-living facility residents were interviewed 2 to 10 weeks after admission, when symptoms of relocation stress syndrome are most likely to appear. Results of this study indicate that the incidence of relocation stress syndrome may be overestimated. More accurate diagnosis and treatment of depression in older adults is needed.  相似文献   
40.
The objective of this paper is to discover which of three forecasting modes used to select parameters for four short-term forecasting techniques minimizes errors. The study also examines whether the amount of historical data used to find parameters contributes to forecasting success. The results show the traditional one-ahead search routine works well in some, but not all, forecasting situations. Also, forecasting errors appear to decline when more historical data are included in the parameter search.  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