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   23198篇
  免费   696篇
  国内免费   4篇
管理学   3032篇
民族学   134篇
人口学   2055篇
丛书文集   100篇
教育普及   1篇
理论方法论   2006篇
综合类   259篇
社会学   11503篇
统计学   4808篇
  2023年   154篇
  2022年   99篇
  2021年   156篇
  2020年   407篇
  2019年   629篇
  2018年   703篇
  2017年   958篇
  2016年   708篇
  2015年   493篇
  2014年   666篇
  2013年   4276篇
  2012年   859篇
  2011年   780篇
  2010年   569篇
  2009年   490篇
  2008年   619篇
  2007年   555篇
  2006年   588篇
  2005年   477篇
  2004年   475篇
  2003年   403篇
  2002年   441篇
  2001年   541篇
  2000年   480篇
  1999年   472篇
  1998年   370篇
  1997年   320篇
  1996年   329篇
  1995年   351篇
  1994年   289篇
  1993年   306篇
  1992年   356篇
  1991年   352篇
  1990年   356篇
  1989年   302篇
  1988年   278篇
  1987年   235篇
  1986年   273篇
  1985年   296篇
  1984年   267篇
  1983年   227篇
  1982年   195篇
  1981年   161篇
  1980年   186篇
  1979年   209篇
  1978年   165篇
  1977年   137篇
  1976年   107篇
  1975年   107篇
  1974年   111篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
721.
This article explores the study of lesbians in the Middle Ages and proposes that the unstable construct of lesbian poses a problem for traditional Medieval Studies that can lead to the development in Medieval Studies of more nuanced and productive theorizing.  相似文献   
722.
Using a spatially extensive urban database constructed from the Maryland Biological Stream Survey (MBSS), we describe the relationships of nutrients in small-order streams to eight defined categories of percent catchment urbanization, correlations between chloride and conductivity in urban streams, and relationships between nutrients and chloride with two Maryland-specific indices of biotic integrity for benthic macroinvertebrates and fish assemblages. Stream nutrients become elevated with increasing percent catchment urbanization, followed by increases in all four measured nitrogen species and total phosphorus at catchment urbanization levels greater than 10%. There was a strong collinear relationship (r 2 = 0.90) between chloride and conductivity (trimeans) across all eight urbanization classes, where Cl (mg/L) = −0.397 + 0.188*conductivity (μS/cm). Critical values for all water quality parameters with the two Maryland biological indices were derived using quantile regression, with significant regressions developed for 11 of 16 water quality parameters and the two biotic indices. For nitrate (NO3-N), the critical thresholds between fair and poor stream quality for the two Maryland biological indices were 0.83 mg/L (benthic macroinvertebrate assemblages) and 0.86 mg/L (fish assemblages). Increasing stream nutrient and chloride levels, associated with widespread catchment urbanization intensity, now affect many small streams in Maryland, with implications for decreasing water quality in major tributaries and the Chesapeake Bay.  相似文献   
723.
The purpose of this study was to determine the degree to which a novel training program based on activities of daily living (ADL) would affect performance of ADLs, as well as the fitness of older adults. Fourteen individuals (mean age 82 years) took part in a 10-week control period followed by a 10-week ADL-based training program. Pre- and posttests included the Physical Performance Test (PPT), the Physical Functional Performance-10 (PFP-10), and the Senior Fitness Test (SFT). After the training period, improvements ranging from 7% to 33% (p<.05) were seen on the PPT and PFP-10 and on three items of the SFT. After conversion to standard scores, the magnitude of change in the PPT and the PFP10 was significantly greater (p<.05) than the magnitude of change in the SFT. These data support the idea that this novel ADL-based training program was able to facilitate improved performance of ADLs, as well as select measures of fitness among older adults.  相似文献   
724.
Ovarian cancer is the leading cause of gynaecological cancer death. The mortality rate of ovarian cancer could be greatly decreased if there were a screening test which was able to detect the disease at an early stage, resulting in an increased probability of cure. The most promising prospect for the early detection of ovarian cancer comes from the rapidly advancing field of clinical proteomics. An increasing number of reports on the potential clinical application of proteomics research for early detection as well as risk assessment and management of ovarian cancer are being published. Although the research is very promising, major technical challenges are still preventing new discoveries in ovarian cancer proteomics from being translated into clinical practice.  相似文献   
725.
University research administrators have been generally ignored in basic studies of research integrity. Hensley noted that research administrators are "essential... to the achievement of the specific missions of postsecondary institutions... and to science and the academic infrastructure". The following study sought to extend the scope of research on research integrity to research administrative structures with a new instrument called the Research Environment Norm Inventory or RENI. University research administrators and their professional association were targeted for data collection. Evidence suggested that research administration in the United States supports integrity in the research environment through: (1) respect for community; (2) respect for institutional boundaries; (3) professionalism; (4) respect for authority structures; (5) sensitivity to system conflicts. The study suggested that integrity structures are dictated largely by the institutional settings and environments.  相似文献   
726.
727.
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   
728.
Psychiatric nurses should support best practices to prevent youth violence. The magnitude and significance of youth violence gives us both social and moral mandates to proceed. Health care professionals have made giant strides in sparing our children from the ravages of childhood diseases. Let us try to do the same by preventing the development of violent behaviors.  相似文献   
729.
730.
Video recording provides an objective record of the content of medical interactions. However, there is concern that cameras may be reactive measurement devices that alter what normally transpires during interactions. This study addressed potential reactivity of cameras in medical interactions. Interactions between 45 patients and 14 medical oncologists were video recorded and coded for camera-related behaviors. Eleven of 45 patients performed none of the behaviors. Among the other patients, camera-related behaviors were infrequent and, on average, constituted about 0.1% (one-tenth of one percent) of total interaction time. Behaviors occurred most often in very early stages of interactions, and when physicians were absent from the room. Seven physicians showed camera-related behaviors, comprising less than 0.1% of the time they were in the interaction. Results suggest video recording can provide nonreactive means of studying medical interactions.
Louis A. PennerEmail:
  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