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   20641篇
  免费   660篇
  国内免费   1篇
管理学   2797篇
民族学   125篇
人口学   1817篇
丛书文集   80篇
教育普及   1篇
理论方法论   1922篇
综合类   191篇
社会学   10470篇
统计学   3899篇
  2023年   141篇
  2022年   88篇
  2021年   139篇
  2020年   378篇
  2019年   557篇
  2018年   652篇
  2017年   852篇
  2016年   663篇
  2015年   455篇
  2014年   618篇
  2013年   3689篇
  2012年   776篇
  2011年   738篇
  2010年   539篇
  2009年   451篇
  2008年   575篇
  2007年   519篇
  2006年   561篇
  2005年   444篇
  2004年   461篇
  2003年   381篇
  2002年   402篇
  2001年   489篇
  2000年   428篇
  1999年   425篇
  1998年   323篇
  1997年   271篇
  1996年   294篇
  1995年   298篇
  1994年   260篇
  1993年   264篇
  1992年   309篇
  1991年   303篇
  1990年   295篇
  1989年   260篇
  1988年   245篇
  1987年   207篇
  1986年   231篇
  1985年   256篇
  1984年   221篇
  1983年   195篇
  1982年   162篇
  1981年   132篇
  1980年   159篇
  1979年   175篇
  1978年   135篇
  1977年   115篇
  1976年   88篇
  1975年   93篇
  1974年   95篇
排序方式: 共有10000条查询结果,搜索用时 578 毫秒
541.
In this article, an integer-valued self-exciting threshold model with a finite range based on the binomial INARCH(1) model is proposed. Important stochastic properties are derived, and approaches for parameter estimation are discussed. A real-data example about the regional spread of public drunkenness in Pittsburgh demonstrates the applicability of the new model in comparison to existing models. Feasible modifications of the model are presented, which are designed to handle special features such as zero-inflation.  相似文献   
542.
543.
ABSTRACT

Acceptance sampling plans offered by ISO 2859-1 are far from optimal under the conditions for statistical verification in modules F and F1 as prescribed by Annex II of the Measuring Instruments Directive (MID) 2014/32/EU, resulting in sample sizes that are larger than necessary. An optimised single-sampling scheme is derived, both for large lots using the binomial distribution and for finite-sized lots using the exact hypergeometric distribution, resulting in smaller sample sizes that are economically more efficient while offering the full statistical protection required by the MID.  相似文献   
544.
We investigated specific award-winning public relations efforts to derive best practices that bridge industry practices with academic research and pedagogy. The data for this project were the winning entries for the annual Public Relations Society of America's (PRSA) Silver Anvil Award, which is considered the top award recognizing excellence in public relations. We found, however, that the archive of award winners does not provide sufficiently definitive information about what defines any public relations discourse genre or why any genre as used is “excellent.” This archival research provides us with a key rationale for employing rhetorical, narrative, and linguistic theories prospectively to guide public relations message design and planning, theories which hitherto have been used to judge campaigns post hoc or retrospectively.  相似文献   
545.
Men's relationships to gender-based violence (GBV) have long been an area of sociological inquiry, but until recently men have primarily been framed as perpetrators of violence against women. More recently, research on men and GBV has broadened to include studying men as victims/survivors, as investigators and law enforcement officers, as passive or active bystanders, and as allies in working to address this social problem. We review this research in an effort to bridge these divergent bodies of work; we identify methodological trends and gaps in existing research, make recommendations for improved theoretical and methodological robustness, and suggest that research perspectives on men and GBV have shifted over time as wider understandings of gender and masculinities become more hopeful and more inclusive. While we see optimism and promise in new directions of GBV research, we urge ongoing research to retain the wisdoms and critical perspectives that marked the beginnings of GBV inquiry.  相似文献   
546.
Due to economic decline and the recent rise in home foreclosure, many U.S. cities are faced with managing large acreages of vacant land. Interest in local food production on this land has the potential to dramatically reshape the composition of greenspace found within urban landscapes. This study examined how the conversion of vacant land to urban gardens and farms influenced arthropod generalist predator populations and their ability to support biocontrol services. We found that the abundance of Coccinellidae and Syrphidae, and the activity density of Carabidae, Formicidae, and Lycosidae were equivalent among vacant lot and urban garden sites. Dolichopodidae abundance and the activity density of Linyphiidae and Opiliones were reduced in urban gardens whereas Anthocoridae abundance and the activity density of Staphylinidae were greater within urban gardens relative to vacant lots. The biocontrol service supplied by generalist predators was measured using sentinel eggs (Helicoverpa zea (Noctuiidae)) and pupae (Sarcophaga bullata (Sarcophagidae) and Musca domestica (Muscidae)). We found no difference in the biocontrol of H. zea eggs or M. domestica pupae among the focal greenspaces. We found no difference in the removal of S. bullata pupae by predators in June 2010, whereas in August 2010 a greater proportion of pupae were removed in urban garden sites relative to vacant lots. Based on these findings, we discuss the potential of the urban landscape to support generalist predators and sustainable urban gardening and farming.  相似文献   
547.
This paper presents a pen picture about the changes of livelihood patterns to the char people, mostly living under poverty in Bangladesh. The study was conducted on the three Northern Districts such as Nilphamari, Lalmonirhat and Pabna in Bangladesh, where the Char Resources Mobilization project was provided by an international non-government organization—Concern Worldwide Bangladesh. The study used mixed method approach where quantitative data were collected from 378 households (126 from each District) using structured interview schedule. A number of qualitative data collection methods such as focus group discussion, participant observation, community mapping, case study, and key informants interview guidelines were used to collect data about the conditions of the Char people in terms of understanding its connection with their livelihoods and socio-economic consequences. This study compares the changes with influential factors with a baseline survey conducted in 2007. Findings showed that there were a number of areas such as education, income, family assets and properties, annual household income, employment, savings, improving market chain, food intake and food security, presence of governmental and non-governmental organizations’ services and awareness about disaster and vulnerability and coping strategies were found positive. The study also observed some negative changes on assets base and livelihood options. The paper argues that the findings on these changes will help to formulate policy on poverty alleviation for the government and non-government authorities who implement the similar type of programmes.  相似文献   
548.
Sociologists continue to observe the ways race permeates America's social institutions, the institution of sport being no exception. Although researchers have explored customer racial discrimination via examinations of the secondary sports card market, only three studies have explored the phenomenon in the context of basketball, a sporting context with a higher proportion of non-White players than the baseball and football leagues that have been the primary focus to date. We explore the unique way race matters on the hardwood by employing a methodological approach that previously has been used to study card collecting in other contexts. Data were obtained for 215 retired players and their rookie cards. Controlling for other factors, to include career performance, position, and card scarcity, the results reveal no direct effect of race on card values, but there is an interaction effect between race and Hall of Fame status that impacts card prices. The potential source and implications of this interaction are discussed as well as suggestions for future research.  相似文献   
549.
This study seeks to extend the body of knowledge of pro-social behavior in comparative market settings by reporting on a high-stakes ultimatum game and revelation game experiments in two transition economies: Kazakhstan and Uzbekistan. While controlling for cultural differences and framing effects, we find statistically significant differences in fairness and honesty behavior between the two countries. Specifically, subjects in Uzbekistan (in an earlier stage of transition to a market economy) are fairer and more honest than their later-stage Kazakh counterparts. Our experimental findings have implications for the literature on pro-social behavior and market economies, and more generally, on the transmission process between formal and informal institutions.  相似文献   
550.
We introduce and study general mathematical properties of a new generator of continuous distributions with one extra parameter called the generalized odd half-Cauchy family. We present some special models and investigate the asymptotics and shapes. The new density function can be expressed as a linear mixture of exponentiated densities based on the same baseline distribution. We derive a power series for the quantile function. We discuss the estimation of the model parameters by maximum likelihood and prove empirically the flexibility of the new family by means of two real data sets.  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