全文获取类型
收费全文 | 13279篇 |
免费 | 269篇 |
国内免费 | 15篇 |
专业分类
管理学 | 1607篇 |
民族学 | 80篇 |
人才学 | 1篇 |
人口学 | 1152篇 |
丛书文集 | 144篇 |
理论方法论 | 1225篇 |
综合类 | 695篇 |
社会学 | 6990篇 |
统计学 | 1669篇 |
出版年
2023年 | 73篇 |
2021年 | 108篇 |
2020年 | 212篇 |
2019年 | 259篇 |
2018年 | 331篇 |
2017年 | 480篇 |
2016年 | 331篇 |
2015年 | 267篇 |
2014年 | 315篇 |
2013年 | 2056篇 |
2012年 | 482篇 |
2011年 | 467篇 |
2010年 | 392篇 |
2009年 | 329篇 |
2008年 | 401篇 |
2007年 | 412篇 |
2006年 | 416篇 |
2005年 | 362篇 |
2004年 | 286篇 |
2003年 | 252篇 |
2002年 | 267篇 |
2001年 | 339篇 |
2000年 | 281篇 |
1999年 | 273篇 |
1998年 | 201篇 |
1997年 | 170篇 |
1996年 | 158篇 |
1995年 | 172篇 |
1994年 | 158篇 |
1993年 | 162篇 |
1992年 | 186篇 |
1991年 | 188篇 |
1990年 | 183篇 |
1989年 | 159篇 |
1988年 | 167篇 |
1987年 | 191篇 |
1986年 | 148篇 |
1985年 | 157篇 |
1984年 | 175篇 |
1983年 | 151篇 |
1982年 | 151篇 |
1981年 | 121篇 |
1980年 | 111篇 |
1979年 | 122篇 |
1978年 | 95篇 |
1977年 | 81篇 |
1976年 | 93篇 |
1975年 | 109篇 |
1974年 | 84篇 |
1972年 | 62篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
92.
A training project in a northern Canadian community providedan opportunity to examine participatory planning approachesand the meaning of work in First Nations communities. Focusgroups conducted three years after the unsuccessful interventionof a community economic development (CED) project suggest thatcomplex factors such as lack of support from community leadersand rate of pay for workers determine whether CED is alwaysappropriate in northern, First Nations contexts. 相似文献
93.
94.
研究了亚当.斯密公路经济理论的几个重要观点:公路的选址和规模、资金筹措、运营和征收车辆通行税等,并分析了车辆通行税管理权划归中央或地方的标准,得出建立监督机制、关注乡村公路和偏远公路有利于公路发展的结论,这对中国公路建设理论与实践有重要的借鉴作用。 相似文献
95.
Formulae are provided that define the ‘bend points’, the beginning and end of the essentially linear dose–response region, for the four‐parameter logistic model. The formulae are expressed in both response and dose units. The derivation of the formulae is shown in order to illustrate the general nature of the methodology. Examples are given that describe how the formulae may be used while planning and conducting bioassays. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
96.
Lesa L. Aylward Robert C. Brunet Thomas B. Starr Gaétan Carrier Elizabeth Delzell Hong Cheng Colleen Beall 《Risk analysis》2005,25(4):945-956
Recent studies demonstrating a concentration dependence of elimination of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) suggest that previous estimates of exposure for occupationally exposed cohorts may have underestimated actual exposure, resulting in a potential overestimate of the carcinogenic potency of TCDD in humans based on the mortality data for these cohorts. Using a database on U.S. chemical manufacturing workers potentially exposed to TCDD compiled by the National Institute for Occupational Safety and Health (NIOSH), we evaluated the impact of using a concentration- and age-dependent elimination model (CADM) (Aylward et al., 2005) on estimates of serum lipid area under the curve (AUC) for the NIOSH cohort. These data were used previously by Steenland et al. (2001) in combination with a first-order elimination model with an 8.7-year half-life to estimate cumulative serum lipid concentration (equivalent to AUC) for these workers for use in cancer dose-response assessment. Serum lipid TCDD measurements taken in 1988 for a subset of the cohort were combined with the NIOSH job exposure matrix and work histories to estimate dose rates per unit of exposure score. We evaluated the effect of choices in regression model (regression on untransformed vs. ln-transformed data and inclusion of a nonzero regression intercept) as well as the impact of choices of elimination models and parameters on estimated AUCs for the cohort. Central estimates for dose rate parameters derived from the serum-sampled subcohort were applied with the elimination models to time-specific exposure scores for the entire cohort to generate AUC estimates for all cohort members. Use of the CADM resulted in improved model fits to the serum sampling data compared to the first-order models. Dose rates varied by a factor of 50 among different combinations of elimination model, parameter sets, and regression models. Use of a CADM results in increases of up to five-fold in AUC estimates for the more highly exposed members of the cohort compared to estimates obtained using the first-order model with 8.7-year half-life. This degree of variation in the AUC estimates for this cohort would affect substantially the cancer potency estimates derived from the mortality data from this cohort. Such variability and uncertainty in the reconstructed serum lipid AUC estimates for this cohort, depending on elimination model, parameter set, and regression model, have not been described previously and are critical components in evaluating the dose-response data from the occupationally exposed populations. 相似文献
97.
文章根据专业学习和技能培训的关系,设计了本科教学的机械设计技能培训模块,为培养大学生的设计技能提供了一个实践平台。 相似文献
98.
The government, the market, and the problem of catastrophic loss 总被引:1,自引:0,他引:1
George L. Priest 《Journal of Risk and Uncertainty》1996,12(2-3):219-237
This article addresses the comparative advantage of the government to the private property/casualty insurance industry for the provision of insurance coverage for catastrophic losses. That the government can play an important role as an insurer of societal losses has been a central public policy principle since at least the New Deal. In addition, our government typically automatically provides forms of specific relief following unusually severe or unexpected disasters, which itself can be viewed as a form of ex post insurance. This article argues that, for systemic reasons, the government is much less effective than the private property/casualty insurance market in providing coverage of losses generally, but especially of losses in contexts of catastrophes. 相似文献
99.
100.
Cariola Sanz L 《International migration (Geneva, Switzerland)》1989,27(2):233-248
This paper discusses the employment situation of Chilean migrant workers, their impact on labor markets in Patagonia, Argentina, and the government's past and projected responses to this phenomenon. In 1980, Chilean inhabitants of patagonia comprised 11% of the area's population. Chilean migration to patagonia was closely linked to economic activities that began to flourish in the 20th century, such as livestock raising, fruit and vegetable cultivation, and mining for coal and petroleum. No Chilean migrants work in a wide range of sectors. In Patagonia's southern provinces availability and ability to withstand rigorous climate conditions are the main factors which account for the prevalence of Chilean manpower. Chilean migrants do not in general displace local manpower. Legislation and the permeability of the border ensure that most workers enter the country as tourists. Clandestine migration is not an issue. Illegal migrants have provoked negative reactions for several reasons: 1) they comprise a marginal population without formal citizenship; 2) being employed as clandestine workers, they pay no social security, nor do their employers; 3) being illegal, they are obliged to accept lower wages and inferior working conditions which creates unfair competition within labor markets; and 4) as a result of these conditions, xenophobic and endophobic attitudes in relations with Argentine nationalists are reinforced. The government has attempted to solve these problems through various measures. Beginning in 1934, most foreigners entered Argentina with a tourist visa, becoming illegal when they stayed beyond authorized limits. Several measures over the years provided amnesty to illegal migrants. Currently, the law promotes immigration, monitors the admission of foreigners to the country and stipulates their rights and obligations. The law lists 115 articles on immigration promotion and on regulation of the movements of foreigners. Because of the present economic crisis in Argentina, authorities are investigating the effect of Chilean manpower on Argentine labor markets. 相似文献