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   98279篇
  免费   2018篇
  国内免费   4篇
管理学   13223篇
民族学   577篇
人才学   25篇
人口学   7972篇
丛书文集   545篇
教育普及   3篇
理论方法论   9827篇
现状及发展   1篇
综合类   2271篇
社会学   46553篇
统计学   19304篇
  2023年   527篇
  2021年   595篇
  2020年   1570篇
  2019年   2265篇
  2018年   2305篇
  2017年   3393篇
  2016年   2580篇
  2015年   2121篇
  2014年   2700篇
  2013年   19055篇
  2012年   2763篇
  2011年   2633篇
  2010年   2169篇
  2009年   2301篇
  2008年   2258篇
  2007年   2095篇
  2006年   2286篇
  2005年   2452篇
  2004年   2305篇
  2003年   2047篇
  2002年   2143篇
  2001年   2259篇
  2000年   2011篇
  1999年   1875篇
  1998年   1597篇
  1997年   1476篇
  1996年   1429篇
  1995年   1438篇
  1994年   1382篇
  1993年   1387篇
  1992年   1429篇
  1991年   1363篇
  1990年   1338篇
  1989年   1178篇
  1988年   1252篇
  1987年   1118篇
  1986年   1032篇
  1985年   1194篇
  1984年   1253篇
  1983年   1122篇
  1982年   1018篇
  1981年   911篇
  1980年   857篇
  1979年   961篇
  1978年   833篇
  1977年   753篇
  1976年   693篇
  1975年   670篇
  1974年   568篇
  1973年   481篇
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
931.
"Net undercount rates in the U.S. decennial census have been steadily declining over the last several censuses. Differential undercounts among race groups and geographic areas, however, appear to persist. In the following, we examine and compare several methodologies for providing small area estimates of census coverage by constructing artificial populations. Measures of performance are also introduced to assess the various small area estimates. Synthetic estimation in combination with regression modelling provide the best results over the methods considered. Sampling error effects are also simulated. The results form the basis for determining coverage evaluation survey small area estimates of the 1900 decennial census."  相似文献   
932.
Suppose X1, X2, ..., Xm is a random sample of size m from a population with probability density function f(x), x>0 and let X1,m<...m,m be the corresponding order statistics. We assume m as an integer valued random variable with P(m=k)=p(1?p)k?1, k=1, 2, ... and 0 and n X1,n for fixed n characterizes the exponential distribution. In this paper we prove that under the assumption of monotone hazard rate the identical distribution of and (n?r+1) (Xr,n?Xr?1,n) for some fixed r and n with 1≤r≤n, n≥2, X0,n=0, characterizes the exponential distribution. Under the assumption of monotone hazard rate the conjecture of Kakosyan, Klebanov and Melamed follows from the above result with r=1.  相似文献   
933.
It is shown that when a parameter lying in a sufficiently small interval is to be estimated in a family of uniform distributions, a two point prior is least favourable under squared error loss. The unique Bayes estimator with respect to this prior is minimax. The Γ-minimax estimator is derived for sets Γ of priors consisting of all priors that give fixed probabilities to two specified subintervals of the parameter space if a two point prior is least favourable in Γ.  相似文献   
934.
In this paper the timing of maternity is estimated by a hazard model. The novel aspect of this paper is that it is shown that wages and total household labor income have a significant effect on the timing of maternity. Both the wage rate of the woman and the wage rate of the husband have a negative effect on the timing of maternity. Total household labor income increases the probability of having a child at an earlier age. Calculated elasticities show that the timing of maternity is relatively elastic with respect to wage rates. However, the elasticities of the decision whether or not to have children altogether are much smaller. Women working in the labor market delay the timing of maternity compared to non-participating women. Attending school has the same effect. Until the age of 28 the maternity hazard increases with age, after that it decreases.We benefited from comments on previous drafts by Siv Gustafsson, Joop Hartog, Peter Kee, Herriette Maassen van den Brink, Eddie Mekkelholt, Joop Odink, Hessel Oosterbeek, Hans van Ophem, Gusta Renes, Andre Voskamp, two anonymous referees, and the Managing Editor of this Journal. This paper is a revised version of a paper presented at the third annual meeting of the European Society for Population Economics, Paris, June 1989. The usual disclaimer applies.  相似文献   
935.
Continued economic stagnation, civil unrest, rural-urban migration, and a series of natural disasters have impeded efforts in the Sudan to integrate women into the development process. Although the Four-Year (1988-1989 to 1991-92) Salvation, Recovery, and Development Programs Plan does not explicitly addresses women's issues, its emphasis on food security, appropriate technology for the agricultural sector, small-scale industries and handicrafts, balanced regional development, and the needs of the poorest 20% of the population guarantees that women will be major recipients. There remains a need, however, to increase women's participation in the development planning process and to base projects on reliable data on women's economic activities. More successful in defining women's needs have been community development projects--Western Savannah Development Corporation, Blue Nile Integrated Rural Development Project, Nuba Mountain Project, and Jebel Marra Rural Development Project--that combine income generation, social welfare, and agricultural research. It is recommended that all such large integrated rural development or agricultural projects allot funds specifically for women's activities and ensure coordination with women's organizations to avoid duplication and identify areas of greatest need. Also urged is the development of appropriate technologies that will alleviate women's double burden of poverty and household chores and address the inequitable distribution of income. Establishment of a women's bureau for women's affairs and development within the National Planning Department would facilitate project formulation and evaluation. In need of change if women in development projects in the Sudan are to be successful are laws that limit female land ownership and practices that deny women loans and credit.  相似文献   
936.
A comparative study conducted in the Sudan illustrated both the potential of a nutrition education program for pregnant women and the many obstacles to creating more optimal maternal nutrition. Included in the study were 1200 women 18-34 years of age attending the Khartoum Province Model Clinic for a minimum of 5 prenatal visits. 83.3% were Muslims and 48.2% were illiterate. The 60 women who comprised the experimental group were exposed to individual nutrition counseling and home visits. Overall, 70% of subjects were anemic, 27% had malaria, and 18% were hookworm. The average weight gain during pregnancy was 4.5 kgs; 25.0% of controls and 20.0% of those in the experimental group gained 3.5-4.0 kgs, 18.3% of controls and 33.3% of experimental subjects gained 4.5-5.0 kgs, and 23.3% of controls and 30.0% of those in the experimental groups gained 5.5 kgs or more. 53.0% of controls and 61.7% of women exposed to nutrition education breastfed for at least 6 months, and 70% of women in the former group and 95% of those in the latter had enrolled their infants in an immunization program. A baseline nutrition questionnaire revealed widespread misinformation, especially a belief that pregnant women should reduce their food intake from 3 to 1-2 meals per day to prevent the fetus from growing too large and making labor difficult. Foods such as fermented sorghum products, fresh fish, and water melon were regarded as abortifacients and avoided, while hot pepper, sour milk, and cola sodas were considered nutritious. Consumption was self-reported to be poor for milk products by 25% of mothers, for meat by 16%, and for fruits and vegetables by 40% Although the educational intervention increased women's knowledge of basic nutrition, it had only a minimal effect on actual practice. This finding is assumed to reflect the widespread belief that men and their guests should be given preference in food allocation, poverty, and avoidance, on the basis of tradition, of many healthy foods. Since 72% of women reported ownership of a television, use if this medium is recommended for nutrition education.  相似文献   
937.
1. Several factors may affect an elderly client's use of medications: polypharmacy, potentially leading to interactions; over-the-counter drugs taken without a physician's knowledge; noncompliance or poor compliance with medication regimens; and ageist beliefs. 2. Psychiatric nurses must be aware that the signs and symptoms they observe may be the result of normal physical or biological aging, psychosocial changes, disease-related changes, medication side effects, or a drug interaction. 3. Nurses must ask two questions when psychotropic drugs are used with elderly clients: What will be the onset, duration, magnitude, and characteristic action of a specific drug in an individual; and What are the characteristics of an "ideal" medication?  相似文献   
938.
1. It is important to examine client and staff satisfaction with the RN case management (RNCM) model to enhance the quality of care in psychiatric settings. 2. Ninety-two percent of clients surveyed ranked the RNCM care as "excellent" or "above average." Clients valued most the humanistic role of the RNCM and repeatedly commented on the importance of the nurse being caring, genuine, and supportive. 3. RNCMs expressed high satisfaction with their role, which they described as collaborative with the psychiatrist, yet also professional and independent. Psychiatrists expressed a high degree of confidence that clients were receiving excellent care by competent nurse professionals.  相似文献   
939.
1. As the nurse-patient relationship evolves through a series of ongoing interactions, both participants become "known" and stir in each other a range of positive and negative emotional reactions. 2. When working with severely psychologically disturbed patients, the nurse's affective and behavioral response can be valuable clues to understanding the patient's early experiences that contribute to the pattern of relatedness and to the formulation of change, enhancing therapeutic interactions. 3. The goals of the countertransference peer supervision group were to recognize unconscious countertransference reactions; unravel the origin and meaning of those countertransference reactions; and collaboratively develop therapeutic nursing interventions.  相似文献   
940.
Elective single mothers are adult, unmarried women who intentionally become mothers. This study utilized longitudinal data about 17 Caucasian, elective single mothers and their children to identify fathers' roles in these families, and to understand children's views of their fathers. These single mothers and their children resided for the first six years of the children's lives in father-absent households. By age six, most of the children had ghost fathers, whom they had never met or knew little about. The data suggest that the father often becomes a family secret, and that children may blame themselves for their fathers' absence.  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