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   13157篇
  免费   357篇
管理学   1929篇
民族学   63篇
人才学   3篇
人口学   1214篇
丛书文集   70篇
理论方法论   1365篇
综合类   328篇
社会学   6076篇
统计学   2466篇
  2021年   69篇
  2020年   176篇
  2019年   231篇
  2018年   257篇
  2017年   373篇
  2016年   338篇
  2015年   241篇
  2014年   309篇
  2013年   2236篇
  2012年   457篇
  2011年   356篇
  2010年   298篇
  2009年   296篇
  2008年   347篇
  2007年   334篇
  2006年   279篇
  2005年   384篇
  2004年   377篇
  2003年   376篇
  2002年   409篇
  2001年   355篇
  2000年   301篇
  1999年   303篇
  1998年   250篇
  1997年   209篇
  1996年   209篇
  1995年   194篇
  1994年   183篇
  1993年   203篇
  1992年   194篇
  1991年   193篇
  1990年   169篇
  1989年   158篇
  1988年   172篇
  1987年   158篇
  1986年   149篇
  1985年   180篇
  1984年   150篇
  1983年   160篇
  1982年   130篇
  1981年   119篇
  1980年   113篇
  1979年   120篇
  1978年   116篇
  1977年   94篇
  1976年   89篇
  1975年   102篇
  1974年   79篇
  1973年   69篇
  1972年   57篇
排序方式: 共有10000条查询结果,搜索用时 250 毫秒
961.
The attempt to recover gambling losses by continuing to gamble (chasing) has featured prominently in accounts of excessive gambling. This research represents the first attempt to operationalize and measure chasing in terms of its cognitive (behavioral intention), emotive (urges) and behavioral components, and to investigate the role of chasing in relation to impaired control over gambling. Two survey samples of 84 male off-course (betting shop) race gamblers (mean age 41, SD = 15) and 137 gaming machine players (73 females, mean age 48, SD = 15 and 64 males, mean age 43, SD = 16) were recruited at gambling venues. Respondents completed a structured questionnaire that investigated retrospective report of chasing and an impaired control scale (The Scale of Gambling Choices). It was found that the various components of chasing formed a composite measure with high internal reliability that was strongly related to indicators of excessive gambling (e.g. time spent gambling, expenditure as a proportion of income) and to impaired control scores. Reacting to large wins by further betting was almost as strongly related to impaired control as was persistence after losing. Those who returned later to chase had significantly higher impaired control scores than those who only chased within a session. Alcohol-related chasing was associated with impaired control over gambling. Chasing of losses and impaired control appear to be generic processes in evidence across both forms of gambling and gender (most format and sex differences were of minor significance).  相似文献   
962.
963.
This study examined the psychosocial functioning of 100 adolescent females (ages 12-17) sentenced to secure care in a southeastern state and the impact of gender-specific, cognitive-behavioral therapy (CBT) intervention on the psychosocial functioning of subjects who reported a history of sexual abuse. The Multidimensional Adolescent Assessment Scale (MAAS) was used to assess psychosocial functioning. Pre-test scores on the MAAS revealed significantly higher scores on 12 of 16 dimensions of psychosocial functioning and higher rates of serious criminal behavior for youth who subsequently disclosed sexual abuse histories as compared to those without such histories. At post-test, statistically significant improvements in psychosocial functioning were observed on 14 of 16 MAAS subscales for those who received the CBT intervention. Thus, incarcerated female adolescents who reported a history of sexual abuse demonstrated more impairment in their functioning as compared to those without a reported history of sexual abuse and responded positively to gender-specific, CBT-based intervention.  相似文献   
964.
Continuous passive motion (CPM) has been proposed as a method to help individuals with low back pain cope with prolonged sitting. The purpose of this study was to investigate the effects that a commercially available CPM device had on lumbar and thoracic erector spinae (ES) muscle activation (using surface electromyography, "EMG"), and on subjective discomfort during prolonged seated computer work with and without the use of the CPM device. There were no significant differences in average ES muscle activation levels, amplitude probability distribution functions, and EMG gaps number and length when sitting with the CPM device was compared to sitting normally. Subjective ratings of discomfort were also not significantly different between the two sitting conditions. The results indicated that there were no clear mechanisms by which the CPM device may reduce ES muscle pain and fatigue for the tasks and pain-free individuals studied.  相似文献   
965.
Parkinsonian disorders (idiopathic Parkinson's disease and clinically similar disorders) are characterized by impaired movements caused by the degeneration of brain centers involved in regulating normal and smooth movements of the body and its extremities. The mechanisms that cause such degeneration are unknown. This Perspective summarizes research described at a meeting held in June 2003, which was organized by the National Institute of Neurological Disorders and Stroke and the National Institute on Aging to provide an update on recent advances in the cell biology of parkinsonian disorders.  相似文献   
966.
Amyloid-beta peptide (Abeta), the pathogenic agent of Alzheimer's disease (AD), is a physiological metabolite in the brain. We have focused our attention and effort on elucidating the unresolved aspect of Abeta metabolism: proteolytic degradation. Among a number of Abeta-degrading enzyme candidates, we used a novel in vivo paradigm to identify a member of the neutral endopeptidase family, neprilysin, as the major Abeta catabolic enzyme. Neprilysin deficiency results in defects in the metabolism of endogenous Abeta 40 and 42 in a gene dose-dependent manner. Our observations suggest that even partial down-regulation of neprilysin activity, which could be caused by aging, can contribute to AD development by promoting Abeta accumulation. Moreover, we discuss the fact that an aging-dependent decline of neprilysin activity, which leads to elevation of Abeta concentrations in the brain, is a natural process that precedes AD pathology. In this Perspective, we hypothesize that neprilysin down-regulation has a role in sporadic AD (SAD) pathogenesis, and we propose that this knowledge be used for developing preventive and therapeutic strategies through use of a G protein-coupled receptor (GPCR).  相似文献   
967.
The fusion of male- and female-derived gametes initiates the phenomenal process of producing a highly complex mammalian organism. Successful reproduction is so important that mammals invoke a battery of protective mechanisms for the germ cell lineages that function to maximize genetic integrity while still allowing genetic diversity and adaptation. Protective mechanisms likely include, but are not limited to, robust DNA repair to safeguard genetic integrity and apoptosis to remove cells with intolerable levels of DNA damage. Analyses of spontaneous mutant frequencies are generally consistent with germline DNA being stringently maintained relative to somatic tissues. Despite the rigorous protection afforded germ cells, genetic integrity is observed to decline with increased maternal and paternal age. It is not yet clear whether cells in the germ line truly age or whether other processes decline or become dysfunctional with age. For example, in a younger animal, the differentiation and/or utilization of germ cells with lower genetic integrity might be disallowed, whereas in an older animal, such cells might slip past these quality-control mechanisms.  相似文献   
968.
969.
Free-choice learning, a new paradigm for the learning that youth and their families engage in outside school, can play an important role in the healthy development of youth, their families, and communities.  相似文献   
970.
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