全文获取类型
收费全文 | 20560篇 |
免费 | 388篇 |
专业分类
管理学 | 2429篇 |
民族学 | 119篇 |
人才学 | 6篇 |
人口学 | 1947篇 |
丛书文集 | 116篇 |
教育普及 | 2篇 |
理论方法论 | 1936篇 |
现状及发展 | 1篇 |
综合类 | 262篇 |
社会学 | 10093篇 |
统计学 | 4037篇 |
出版年
2023年 | 116篇 |
2022年 | 85篇 |
2021年 | 119篇 |
2020年 | 341篇 |
2019年 | 539篇 |
2018年 | 560篇 |
2017年 | 764篇 |
2016年 | 524篇 |
2015年 | 406篇 |
2014年 | 497篇 |
2013年 | 3539篇 |
2012年 | 750篇 |
2011年 | 648篇 |
2010年 | 521篇 |
2009年 | 481篇 |
2008年 | 556篇 |
2007年 | 554篇 |
2006年 | 517篇 |
2005年 | 464篇 |
2004年 | 453篇 |
2003年 | 430篇 |
2002年 | 425篇 |
2001年 | 507篇 |
2000年 | 407篇 |
1999年 | 407篇 |
1998年 | 327篇 |
1997年 | 297篇 |
1996年 | 308篇 |
1995年 | 291篇 |
1994年 | 277篇 |
1993年 | 272篇 |
1992年 | 314篇 |
1991年 | 311篇 |
1990年 | 266篇 |
1989年 | 269篇 |
1988年 | 255篇 |
1987年 | 237篇 |
1986年 | 227篇 |
1985年 | 261篇 |
1984年 | 248篇 |
1983年 | 245篇 |
1982年 | 186篇 |
1981年 | 170篇 |
1980年 | 181篇 |
1979年 | 176篇 |
1978年 | 145篇 |
1977年 | 142篇 |
1976年 | 127篇 |
1975年 | 124篇 |
1974年 | 106篇 |
排序方式: 共有10000条查询结果,搜索用时 13 毫秒
131.
This article discusses the role of migration in relieving population pressures, thus making continuing development possible, using small nations in the Caribbean and the South Pacific as examples. The Caribbean islands and many Pacific islands have used out-migration to ease population pressures in this century. Surplus labor has been emerging in various Caribbean nations, independent of the international marketing problems of plantation agriculture. Rural populations alienated from plantations have had to make do on questionable and/or remote land. Population surpluses appear to originate in rural areas, but little evidence exists to suggest that those surpluses are the basis for the emigration patterns of the Caribbean islands. Emigration does not solve population problems because when ambitious, skilled workers leave their country, their actions have little to do with the existence of domestic surplus labor and their leaving may do little to facilitate domestic labor absorption. Thus, if mini-states wish to sustain their hopes of economic expansion, they must find the means to employ their surplus labor. Since mainly skilled migrants leave, their going may actually slow development and retard opportunities for labor absorption. Population movements internal to the Caribbean region may further complicate surplus labor and/or population problems. If protective entry requirements impede normal inter-island relations, they may interfere with developmental processes. In general, migration is not a feasible strategy for population control for small island nations. While temporary migration has a more positive impact than other forms of migration, problems do exist. For example, temporary migration 1) can impose significant economic costs on the source-country, and 2) may result in the source country being unable to capitalize on its initial investment in training and education of temporary migrants. In conclusion, import substitution through cooperation between small island nations, production for export where feasible, and more attention to more sophisticated international service linkages hold a better prospect for material progress than relying on the export of surplus populations. 相似文献
132.
A face-to-face survey conducted in 1984 with a sample of 1491residents of the Detroit metropolitan area (including an oversampleof older adults) and a reinterview of a random subset of theserespondents by telephone were used to compare the two modesof data collection across two age levels. Except for a tendencytoward a disproportionately large number of DK answers and adisproportionately large amount of interviewer assistance onthe telephone, respondents 60 years of age and older did notexhibit larger mode differences than did respondents under 60.For both age groups, response distributions were rather similar,suggesting little effect of mode. Likewise, response style differedlittle by mode, while a higher proportion of missing data (i.e.,"I don't know" answers) was given on the telephone. The responserate for the telephone reinterview was 90%, somewhat lower forolder than younger persons. The findings support the feasibilityof using the telephone for reinterviewing older adults. 相似文献
133.
Greenspan A 《Asia-Pacific population & policy》1992,(20):1-4
Bangladesh has a population of 115 million people, and the economic growth rate of 3.7% during the 1980s was undermined by rapid population growth. The annual population growth rate was 3% in the 1960s and early 1970s, 2.5% between 1981-91 decreasing to 2.3% in 1991. The average of number of children is 4.6/woman compared with 7 in the 1960s. Infant mortality dropped from 150/1000 births in 1976 to 118/1000 in 1991. Life expectancy rose from 47 to 54 years. The 1991 Contraceptive Prevalence Survey showed that 39.9% of married women under 50 use contraceptives in 1991 vs. 18.6% in 1981. The use of modern methods increased from 10.9% in 1981 to 31.2% in 1991, while traditional methods rose from 7.7% to 8.7%. Sterilization was most prevalent in 1981. 29,000 female family planning (FP) workers were aggressively engaged in dispensing FP services in 1990. The Social Marketing Company sells pills, condoms, and oral rehydration salts through 130,000 retail outlets. The 1989 Contraceptive Prevalence Survey showed that 40% of pill and condom users obtained them from this network, and 95.4% of women knew about 4 methods of contraception. In 1990 there were 120 private organizations providing contraceptive services. Some of the components of the government FP program include field worker distribution door-to-door of injectable contraceptives (50% injectable usage rate in the Matlab project); recordkeeping activities; a satellite clinic network with access to contraceptive services; and decentralization through the Upazila (subdistrict) approach. The logistics system of FP has improved the warehousing, transportation, and management information system. Foreign aid (mainly USAID) financing of contraceptives helped avert 14.4 million births between 1974-90. The increase of contraceptive prevalence to 50% by 1997 would avert another 21.9 million births during 1991-96 (replacement fertility requires 70% prevalence. 相似文献
134.
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
135.
136.
137.
138.
The day-to-day management of medical practice is so heavily influenced by tactical imperatives that few physicians have the time to think strategically. Traditionally, the difference between tactics and strategy is not a major concern of most physician executives. The realm of tactics is the short run, when managers must make do with the fixed resources at hand. Strategy addresses the long run, when all resources and markets are variable. A tactical focus is understandable, maybe even acceptable, in industries where nothing challenges traditional approaches to production of an established product or service. However, medical care in the 1990s is changing so fast that a physician executive must devote an incredible amount of time and effort just to stay confused about what is going on. 相似文献
139.
College newspapers are a powerful but underutilized medium for educating students on health issues, including those related to drug and alcohol use on campus. Editors of these publications are in a position to wield significant influence among their readers. In addition to communicating factual information about the prevalence and impact of substance use among college students, editors can use the press to advocate changes in students' attitudes and behaviors and in college or community policies that affect substance use. A pilot conference was held to help New England college newspaper editors perceive the importance of their role in educating their peers about substance use and other health-related issues, and to offer concrete suggestions as to how they can incorporate these topics into an "activist" campus press. 相似文献
140.