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   19577篇
  免费   603篇
  国内免费   1篇
管理学   2611篇
民族学   113篇
人口学   1737篇
丛书文集   74篇
教育普及   1篇
理论方法论   1755篇
综合类   181篇
社会学   9952篇
统计学   3757篇
  2023年   130篇
  2022年   80篇
  2021年   135篇
  2020年   347篇
  2019年   517篇
  2018年   609篇
  2017年   794篇
  2016年   613篇
  2015年   409篇
  2014年   571篇
  2013年   3528篇
  2012年   740篇
  2011年   684篇
  2010年   499篇
  2009年   408篇
  2008年   532篇
  2007年   487篇
  2006年   521篇
  2005年   409篇
  2004年   422篇
  2003年   352篇
  2002年   364篇
  2001年   471篇
  2000年   418篇
  1999年   403篇
  1998年   313篇
  1997年   265篇
  1996年   281篇
  1995年   289篇
  1994年   247篇
  1993年   258篇
  1992年   300篇
  1991年   294篇
  1990年   288篇
  1989年   254篇
  1988年   238篇
  1987年   201篇
  1986年   229篇
  1985年   251篇
  1984年   216篇
  1983年   191篇
  1982年   159篇
  1981年   130篇
  1980年   156篇
  1979年   171篇
  1978年   133篇
  1977年   114篇
  1976年   87篇
  1975年   91篇
  1974年   94篇
排序方式: 共有10000条查询结果,搜索用时 796 毫秒
281.
The consensus is that, in spite of a reluctance in Washington to undertake any drastic reform of the health care financing and delivery system, the changes that are already in place in individual organizations and that are in place or being contemplated at the state level are certain to make the health care system of tomorrow very different from that of today. Physician executives can play an important role in the transition that will be required, but they will have to use a flexible, especially nondogmatic approach if they wish to cope successfully in this increasingly whirling environment. For such physicians, the author says, the opportunities, though unknown, are enormous.  相似文献   
282.
There is much truth in the adage that "the more things change, the more they stay the same." Nowhere does this seem more apparent than in health care where, amidst monumental reconfiguration, basic foundations of physician-patient relationships and attention to the impact of psychosocial factors on health and health care delivery remain as critical influences. While the importance of the therapeutic relationship and the influence of psychosocial factors in medical care has been clear in traditional systems of delivery, these factors may be even more critical in managed care systems. These emphases must be incorporated by design, however, and not left to default.  相似文献   
283.
Physicians practicing in large, multispecialty medical groups share an organizational culture that differs from that of physicians in small or independent practices. Since 1980, there has been a sharp increase in the size of multispecialty group practice organizations, in part because of increased efficiencies of large group practices. The greater number of physicians and support personnel in a large group practice also requires a relatively more sophisticated management structure. The efficiencies, conveniences, and management structure of a large group practice provide an optimal environment to practice medicine. However, a search of the literature found no data linking a large group practice environment to practice outcomes. The purpose of the study reported in this article was to determine if physicians in large practices have fewer quality and utilization problems than physicians in small or independent practices.  相似文献   
284.
The literature is replete with theoretical discussions of medical quality management, particularly of the measurement of quality in the health care setting. While there is a growing body of knowledge on both quality and its measurement, this author questions whether medical quality can ever be quantified. He says that the concept of quality is still a moving target, so that the value of attempts at quantification can only be short-lived.  相似文献   
285.
This paper describes a model which relates fertility to partner availability, an aspect of relative cohort size. Partner availability is affected by the tendency for males to reproduce at a later age than females. For women born at a time of rising birth rates, there is a shortage of slightly older men as potential partners. Women born when birthrates are falling enjoy a surplus of older men from which to choose. This model is believed to be the first non-linear demographic feedback model involving feedbacks through marriage squeezes in which empirically estimated values of the parameters imply persistent limit cycles. The deterministic model makes births in each five-year period a function of births in previous five-year periods. The form of the function is chosen to model the effect of partner availability upon entry into reproductive relationships, and therefore on age-specific fertility. Marriage rates are not modeled directly. The model was developed from data for more than a century from England and Wales, New Zealand, and the US. The demographic transition is modeled with a logistic function and age-specific fertility rates are estimated using lognormal distributions. The stepwise inclusion of a partner availability estimate in the model showed that it accounts for 29% of otherwise unexplained variance. Projected future births stabilize in sustained or limit cycles with periods a little longer than 40 years, and amplitudes of at least 7% of the mean. The necessary conditions for cycle persistence are outlined on a graph of maximum and minimum fertility parameters.  相似文献   
286.
This review of current knowledge about emigration dynamics from and within South Asia (Bangladesh, India, Pakistan, and Sri Lanka) opens with a brief history of the three phases of emigration from the area since the 1830s (plantation labor; postindependence to the UK, US, Canada, and Australia; and labor migration to the oil-exporting countries). The influence of the creation of Pakistan and Bangladesh is also covered as are British colonial and commonwealth policies. It is noted that migration data are incomplete and that India exhibits an ambivalence about collecting such information. The discussion then turns to emigration since 1970 and considers permanent migration from South Asia to the traditional receivers; South Asian asylum seekers in Europe; South Asian refugees, illegal migrants, migrant workers (flows and destinations), the stock of contract migrant workers (and their characteristics); returnee migrant workers; and skill levels. Analysis is provided of macro level determinants of emigrations such as gross national product (level and growth), the general demographic and social situation, labor force growth and structure, poverty and inequality, and internal and international migration. Environmental factors causing displacement in Southern Asia include floods, cyclones, river bank erosion, drought, and desertification. Global warming could displace millions of people in the region, and development projects have contributed to displacement. The remainder of the report covers political and ethnic factors, micro-factors influencing migration decision-making, the policies of sending and receiving countries, the consequences of emigration, and the potential for migration in the future.  相似文献   
287.
This paper introduces a drawing technique developed by the author for use in the assessment and treatment of individuals and families. The client is invited to draw a floor plan of his or her home or apartment, or an aerial view of un outdoor area. The drawing is then discussed and considered as a means of understanding critical elements of the experience of life space. The material derived is discussed from the eerspectives of family systems, psychodynamic, and abuse treatment theories, with special reference to notions of family structure, boundary, the self, and memory. Emphasis is placed on the actual physical layout of the home, as well as the subjective experience of it. Applications of the drawing technique for exploring memories are illustrated. Case examples are presented from clinical trials with children and adults in residential treatment, inpatient, and outpatient settings.The Heller Financial Corporation generously supports the development of household and spatial drawings for treatment and prevention. A version of this paper was presented at the 43rd Annual Meeting of the American Association of Psychiatric Services for Children, New Orleans, February 26, 1992. The author wishes to thank Robert B. Bloom, Ph.D., Excutive Director of JCB, for supporting the development of ideas and techniques discribed in this paper.  相似文献   
288.
"This article argues that the question of free movement vs. exclusion within the European Union (EU) can be addressed satisfactorily only if we move away from the narrow state-centrism inherent in the current debate. What is required is to 'open' the state concept and examine the implications of state-society relations for EU policy making. Once this is done, it can be seen that the exclusionist stance of the immigration policy and the essentially intergovernmental nature of the policy making are due to an implicit contract between states and constituents implied by the concepts of nationality and citizenship. According to this perspective, the focus on the state or the political elite alone is too one-sided and misses the more complex factors bearing upon EU policy making in this area."  相似文献   
289.
This study is based on interviews with grandmothers during July-September 1992-93 in Sudan. The study shows that grandmothers play a significant role in health education and child care within families in the Sudan. Grandmothers, who are not aware of the changes in knowledge, also promote harmful traditions. The authors recommend that health education be directed to elderly women and grandmothers in order to change beliefs and practices that continue to be harmful to children and mothers. Grandmothers were found to give sound advice on child birth, such as movement during labor, breast feeding immediately after birth, and birth intervals of 2-4 years. Grandmothers also gave sound advice on good nutritional practices during pregnancy and use of fermented cereals as weaning foods. Grandmothers recommended use of fenugreek for lactating mothers and use of mint and haharaib for stomach upsets, remedies that are beneficial. Babul is useful after an episiotomy for its antibacterial effects. Harmful advice includes recircumcision after delivery, short birth intervals, and avoidance of contraception. Female genital mutilation (FGM) is a major practice that exposes girls and mothers to a greater risk of mortality during childbirth and pregnancy. The sample of grandmothers agreed on the importance of sex education for a girl before marriage. Unfortunately, 57% of grandmothers recommended 14 years as a suitable age for marriage. Grandmothers generally believed wrongly that riding bicycles, drinking coffee, and wearing trousers by girls would increase their sexual desires. Grandmothers explained menstruation to granddaughters and offered home-made remedies for cramps. 45% believed that there were no disadvantages to FGM and recommended FGM at ages 2-5 years. Most viewed fevers as a danger that required a doctor's care. Advice varied among grandmothers according to socioeconomic class.  相似文献   
290.
Consider a randomized trial in which time to the occurrence of a particular disease, say pneumocystis pneumonia in an AIDS trial or breast cancer in a mammographic screening trial, is the failure time of primary interest. Suppose that time to disease is subject to informative censoring by the minimum of time to death, loss to and end of follow-up. In such a trial, the censoring time is observed for all study subjects, including failures. In the presence of informative censoring, it is not possible to consistently estimate the effect of treatment on time to disease without imposing additional non-identifiable assumptions. The goals of this paper are to specify two non-identifiable assumptions that allow one to test for and estimate an effect of treatment on time to disease in the presence of informative censoring. In a companion paper (Robins, 1995), we provide consistent and reasonably efficient semiparametric estimators for the treatment effect under these assumptions. In this paper we largely restrict attention to testing. We propose tests that, like standard weighted-log-rank tests, are asymptotically distribution-free -level tests under the null hypothesis of no causal effect of treatment on time to disease whenever the censoring and failure distributions are conditionally independent given treatment arm. However, our tests remain asymptotically distribution-free -level tests in the presence of informative censoring provided either of our assumptions are true. In contrast, a weighted log-rank test will be an -level test in the presence of informative censoring only if (1) one of our two non-identifiable assumptions hold, and (2) the distribution of time to censoring is the same in the two treatment arms. We also extend our methods to studies of the effect of a treatment on the evolution over time of the mean of a repeated measures outcome, such as CD-4 count.  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