全文获取类型
收费全文 | 33780篇 |
免费 | 134篇 |
国内免费 | 1篇 |
专业分类
管理学 | 4596篇 |
民族学 | 188篇 |
人才学 | 2篇 |
人口学 | 3086篇 |
丛书文集 | 142篇 |
教育普及 | 2篇 |
理论方法论 | 2983篇 |
现状及发展 | 1篇 |
综合类 | 367篇 |
社会学 | 16306篇 |
统计学 | 6242篇 |
出版年
2024年 | 192篇 |
2023年 | 276篇 |
2022年 | 170篇 |
2021年 | 243篇 |
2020年 | 683篇 |
2019年 | 886篇 |
2018年 | 1073篇 |
2017年 | 1355篇 |
2016年 | 1058篇 |
2015年 | 712篇 |
2014年 | 939篇 |
2013年 | 5758篇 |
2012年 | 1270篇 |
2011年 | 1103篇 |
2010年 | 840篇 |
2009年 | 726篇 |
2008年 | 885篇 |
2007年 | 814篇 |
2006年 | 816篇 |
2005年 | 700篇 |
2004年 | 704篇 |
2003年 | 602篇 |
2002年 | 636篇 |
2001年 | 759篇 |
2000年 | 686篇 |
1999年 | 638篇 |
1998年 | 485篇 |
1997年 | 437篇 |
1996年 | 437篇 |
1995年 | 449篇 |
1994年 | 378篇 |
1993年 | 406篇 |
1992年 | 444篇 |
1991年 | 432篇 |
1990年 | 447篇 |
1989年 | 414篇 |
1988年 | 394篇 |
1987年 | 333篇 |
1986年 | 373篇 |
1985年 | 408篇 |
1984年 | 373篇 |
1983年 | 345篇 |
1982年 | 269篇 |
1981年 | 229篇 |
1980年 | 248篇 |
1979年 | 295篇 |
1978年 | 211篇 |
1977年 | 197篇 |
1976年 | 169篇 |
1975年 | 167篇 |
排序方式: 共有10000条查询结果,搜索用时 23 毫秒
31.
Hervitz HM 《The International migration review》1985,19(2):293-317
This study, based on Brazilian data from 1976, compared the fertility of migrants and stayers at both origin and destination areas. Observed patterns of fertility differentials were then analyzed in terms of 4 hypotheses of fertility behavior focused on processes of socialization, adaptation, selectivity, and disruption. In the study sample, 31% of migrants moved from rural to urban areas, 45% of moves were between urban areas, and 20% of moves were between rural areas. Among rural-to-urban migrants, only 1/3 moved from traditional to modern regions. To uncover the main patterns of migrant and stayer fertility differentials in the study population, the major flows of migrants by origin and destination were disaggregated by recency of migration, education, and age. The overall conclusions were as follows: 1) rural-urban migration flows need to be disaggregated into various modern/traditional cross-classifications (e.g., modern-rural, traditional-urban, frontier-urban) and greater emphasis needs to be placed on rural-urban, urban-urban, and rural-rural flows; 2) no robust quantitative measures of migrant-stayer fertility differentials held across migrant groups, implying that migrants differing in terms of age, education, origin, and destination are likely to behave in significantly variable fashion with regard to stayer standards of fertility behavior; 3) migrant groups with overall lower fertility levels, such as the young and better educated, are less likely to experience significant fertility reduction to bridge the origin/destination fertility gap; 4) rural-to-rural migrants do not appear to experience any lasting fertility reduction even when they move to areas with lower overall fertility rates; 5) urban-to-rural migrants tend to bridge a larger fraction of the uphill fertility gap than rural-to-urban migrants; and 6) there was evidence of partial adaptation for most migrant categories once disruption effects disappear and evidence consistent with the socialization hypothesis (no fertility reduction for at least 1 generation) was apparent for migrants originating in the least developed parts of Brazil, the frontier region, and the traditional-rural region. 相似文献
32.
Ecosystems are formed by organisations that jointly create a value proposition that a single firm could not create in isolation. To deliver this value proposition, the partners need a focal firm, the orchestrator, to be align them towards the joint value proposition. Thus, how orchestrators design the alignment structure of an ecosystem is at the very heart of the ecosystem concept – yet it has not been sufficiently addressed by extant research. This is all the more true for the question of how the design of an ecosystem is shaped depending on surrounding conditions. This paper applies a qualitative study with ten cases and, based on the attention-based view of the firm, contributes to research on ecosystems in several ways. First, it explains which ecosystem designs are beneficial under which conditions. Second, it elucidates the structure and activities within ecosystems and shows that start-ups can be just as good ecosystem orchestrators as incumbents. Third, it explains the circumstances under which single vs. multi orchestrator ecosystems occur. Fourth, it presents the conditions when incumbents or start-ups make better orchestrators. Finally, it is among the first studies to apply the attention-based view to business ecosystems, and shows that doing so yields intriguing insights into this emerging field of research. 相似文献
33.
Information about board-and-care homes reported in the media and in federal committee hearings indicates that they are shoddy and exploitative environments that do not provide adequate care. Research done in board-and-care homes in recent years, however, demonstrates that they can provide adequate care and a satisfying environment for some of the people they serve. Policy at the federal, state, and local levels should be guided by both the need to assure the health and safety of board-and-care residents and the needs of residents and operators identified in scientific studies. 相似文献
34.
"A human capital framework is utilized to examine the economic progress of nine nationality groups of foreign workers [in Kuwait] using data from the 1983 national Labor Survey. The sources of earnings' variations of particular interest to us included different degrees of education and experience transferability, occupational affiliation and ethnic background. In general, the results derived from the analysis suggest that 1) foreign workers achieve a discernible economic progress as their residence lengthens; 2) the rate of economic progress varies depending on worker's education, home and Kuwait-specific experience, occupational status and ethnic background; and 3) about one third of the earnings inequality is due to unexplained factors including discrimination." 相似文献
35.
36.
The health care provider marketplace continues to undergo dramatic changes with the advent of hospital mergers, acquisitions, and physician and hospital alliances. In this era of managed care, cost containment is still vital to a hospital's success, but many stakeholders--patients, employers, and physicians--are determined that quality of care also remain paramount. How can hospitals reduce their expenses and maintain a quality focus? The answer lies in a successful clinical reengineering initiative. One progressive model of clinical reengineering is presented, as well as examples of initiatives at three health care institutions. Initial results of clinical redesign programs have been dramatic and encouraging, with documented evidence of simultaneous cost savings and improved patient care. 相似文献
37.
Experiments involving large social units, such as schools, work sites, or whole cities, are commonly limited in statistical power because the number of randomized units is small, leaving few degrees of freedom for residual (between-unit) error. The authors describe a method for increasing residual degrees of freedom in a community experiment without substantially increasing cost or difficulty. In brief, they propose that the experimental units should be divided into random subsamples (batches). Batch sampling can improve statistical power if the community endpoint means are stable over time or if their temporal variation is comparable in period to the batch-sampling schedule. The authors demonstrate the theoretical advantages of the batch system and illustrate its use with data from the Pawtucket Heart Health Program, in which such a design was implemented. 相似文献
38.
"Section 2 will first extend the method of mixed estimation to maximum likelihood estimation in general. Then, we will review generalized linear models with logistic and Poisson regressions as examples. In Section 3 we discuss different approaches for formulating the auxiliary information in practice. Section 4 first reviews the method of Coale and Kisker, provides empirical estimates for it, and then proceeds with the mixed estimation variant. In Section 5 we apply the methods to the estimation of mortality at ages 80+ in Finland in 1980-1993. We will first consider the evidence for mortality crossover between males and females....Then we will estimate life expectancies at age 100." (EXCERPT) 相似文献
39.
40.