全文获取类型
收费全文 | 19661篇 |
免费 | 367篇 |
国内免费 | 2篇 |
专业分类
管理学 | 2736篇 |
民族学 | 103篇 |
人才学 | 4篇 |
人口学 | 1757篇 |
丛书文集 | 111篇 |
理论方法论 | 1907篇 |
综合类 | 505篇 |
社会学 | 9456篇 |
统计学 | 3451篇 |
出版年
2021年 | 110篇 |
2020年 | 256篇 |
2019年 | 414篇 |
2018年 | 461篇 |
2017年 | 659篇 |
2016年 | 501篇 |
2015年 | 365篇 |
2014年 | 461篇 |
2013年 | 3279篇 |
2012年 | 668篇 |
2011年 | 601篇 |
2010年 | 475篇 |
2009年 | 456篇 |
2008年 | 479篇 |
2007年 | 502篇 |
2006年 | 429篇 |
2005年 | 486篇 |
2004年 | 451篇 |
2003年 | 415篇 |
2002年 | 476篇 |
2001年 | 509篇 |
2000年 | 434篇 |
1999年 | 414篇 |
1998年 | 330篇 |
1997年 | 294篇 |
1996年 | 300篇 |
1995年 | 260篇 |
1994年 | 267篇 |
1993年 | 268篇 |
1992年 | 292篇 |
1991年 | 277篇 |
1990年 | 276篇 |
1989年 | 254篇 |
1988年 | 240篇 |
1987年 | 255篇 |
1986年 | 223篇 |
1985年 | 283篇 |
1984年 | 259篇 |
1983年 | 254篇 |
1982年 | 210篇 |
1981年 | 169篇 |
1980年 | 185篇 |
1979年 | 191篇 |
1978年 | 180篇 |
1977年 | 147篇 |
1976年 | 142篇 |
1975年 | 157篇 |
1974年 | 142篇 |
1973年 | 112篇 |
1972年 | 100篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
221.
222.
Spencer G. Niles Walter P. Anderson Gary Goodnough 《The Career development quarterly》1998,46(3):262-275
Responses to the Adult Career Concerns Inventory (ACCI: Super, Thompson, Lindeman, Myers, & Jordaan, 1988) were organized through cluster analysis to identify different ways in which adults use exploratory behavior to cope with career development tasks. Significant differences in life-role salience among the types of adult career explorers identified were also investigated. Findings indicated a variety of ways in which adults use exploratory behavior. However, no significant differences were found in life-role salience among the types of career explorers. The discussion explains how career counselors can interpret their clients' ACCI profiles to select appropriate career interventions. 相似文献
223.
This study explored the relationship between US immigration laws and their impact on the immigration of Asian professionals. The article relied on a 1996 Population Association presentation. Data were obtained from the US Immigration and Naturalization Service on legally admitted immigrants to the US. The authors describe the paths to admission, trends in immigration of professionals during 1972-94, and the Immigration Act of 1965 and its 4 amendments. Standardization-decomposition techniques are used to explain the relative differences in professional immigration across 1972-77, 1978-91, and 1992-94. The crude professional rate for all Asians declined by 19% during 1972-91. 62% of the decline was due to changes in the class of admission composition, and 25% was due to a decline in the class-specific professional rates. During 1992-94, the Asian crude professional rate increased 7%, most of which was due to changes in class composition, with the exception of Korean rates. Only the Vietnamese experienced a decline in rates. The 1965 law allowed for equity between countries in admission. The paths of immigration were family ties, job skills, or refugee status. During 1972-77, Chinese took advantage of family reunification, and Indians entered on employment preferences. The legal changes affected the size and share of each class of admission. The revisions indirectly affected the occupational selectivity of immigrant groups. 27% of the flow of Asians during 1972-77 was accounted for by employment preferences. Professionals were 44% of Asian immigrants during 1972-77, 26% during 1978-91, and 33% during 1992-94. 相似文献
224.
A non-linear model for examining genotypic responses across an array of environments is contrasted with the 'joint regression' formulation, and a rigorous approach to hypothesis testing using the conditional error principle is demonstrated. The model is extended to cater for situations where single straight-line response patterns fail to characterize genotypic behaviors over an environmental array: a combination of two straight lines, with slope in below-average and in above-average environments, is offered as the 1 2 simplest representation of convex and concave patterns. A protocol for classifying genotypes according to the results of hypothesis tests, i.e. H( = ) and H( = = = 1), is 1 2 1 2 presented . A doubly desirable response pattern is convex ( < 1< ), while a doubly 1 2 undesirable pattern is concave ( > 1> ). 1 2 相似文献
225.
Sample selection in radiocarbon dating 总被引:1,自引:0,他引:1
J. A. Christen & C. E. Buck 《Journal of the Royal Statistical Society. Series C, Applied statistics》1998,47(4):543-557
Archaeologists working on the island of O'ahu, Hawai'i, use radiocarbon dating of samples of organic matter found trapped in fish-pond sediments to help them to learn about the chronology of the construction and use of the aquicultural systems created by the Polynesians. At one particular site, Loko Kuwili, 25 organic samples were obtained and funds were available to date an initial nine. However, on calibration to the calendar scale, the radiocarbon determinations provided date estimates that had very large variances. As a result, major issues of chronology remained unresolved and the archaeologists were faced with the prospect of another expensive programme of radiocarbon dating. This paper presents results of research that tackles the problems associated with selecting samples from those which are still available. Building on considerable recent research that utilizes Markov chain Monte Carlo methods to aid archaeologists in their radiocarbon calibration and interpretation, we adopt the standard Bayesian framework of risk functions, which allows us to assess the optimal samples to be sent for dating. Although rather computer intensive, our algorithms are simple to implement within the Bayesian radiocarbon framework that is already in place and produce results that are capable of direct interpretation by the archaeologists. By dating just three more samples from Loko Kuwili the expected variance on the date of greatest interest could be substantially reduced. 相似文献
226.
J. E. Kelsall & P. J. Diggle 《Journal of the Royal Statistical Society. Series C, Applied statistics》1998,47(4):559-573
A common problem in environmental epidemiology is the estimation and mapping of spatial variation in disease risk. In this paper we analyse data from the Walsall District Health Authority, UK, concerning the spatial distributions of cancer cases compared with controls sampled from the population register. We formulate the risk estimation problem as a nonparametric binary regression problem and consider two different methods of estimation. The first uses a standard kernel method with a cross-validation criterion for choosing the associated bandwidth parameter. The second uses the framework of the generalized additive model (GAM) which has the advantage that it can allow for additional explanatory variables, but is computationally more demanding. For the Walsall data, we obtain similar results using either the kernel method with controls stratified by age and sex to match the age–sex distribution of the cases or the GAM method with random controls but incorporating age and sex as additional explanatory variables. For cancers of the lung or stomach, the analysis shows highly statistically significant spatial variation in risk. For the less common cancers of the pancreas, the spatial variation in risk is not statistically significant. 相似文献
227.
I. Bray & D. E. Wright 《Journal of the Royal Statistical Society. Series C, Applied statistics》1998,47(4):589-602
Data collected before the routine application of prenatal screening are of unique value in estimating the natural live-birth prevalence of Down syndrome. However, much of these data are from births from over 20 years ago and they are of uncertain quality. In particular, they are subject to varying degrees of underascertainment. Published approaches have used ad hoc corrections to deal with this problem or have been restricted to data sets in which ascertainment is assumed to be complete. In this paper we adopt a Bayesian approach to modelling ascertainment and live-birth prevalence. We consider three prior specifications concerning ascertainment and compare predicted maternal-age-specific prevalence under these three different prior specifications. The computations are carried out by using Markov chain Monte Carlo methods in which model parameters and missing data are sampled. 相似文献
228.
Finite mixture models with concomitant information: assessing diagnostic criteria for diabetes 总被引:1,自引:0,他引:1
T. J. Thompson P. J. Smith & J. P. Boyle 《Journal of the Royal Statistical Society. Series C, Applied statistics》1998,46(3):393-404
The World Health Organization (WHO) diagnostic criteria for diabetes mellitus were determined in part by evidence that in some populations the plasma glucose level 2 h after an oral glucose load is a mixture of two distinct distributions. We present a finite mixture model that allows the two component densities to be generalized linear models and the mixture probability to be a logistic regression model. The model allows us to estimate the prevalence of diabetes and sensitivity and specificity of the diagnostic criteria as a function of covariates and to estimate them in the absence of an external standard. Sensitivity is the probability that a test indicates disease conditionally on disease being present. Specificity is the probability that a test indicates no disease conditionally on no disease being present. We obtained maximum likelihood estimates via the EM algorithm and derived the standard errors from the information matrix and by the bootstrap. In the application to data from the diabetes in Egypt project a two-component mixture model fits well and the two components are interpreted as normal and diabetes. The means and variances are similar to results found in other populations. The minimum misclassification cutpoints decrease with age, are lower in urban areas and are higher in rural areas than the 200 mg dl-1 cutpoint recommended by the WHO. These differences are modest and our results generally support the WHO criterion. Our methods allow the direct inclusion of concomitant data whereas past analyses were based on partitioning the data. 相似文献
229.
We draw upon evidence from a qualitative study of headhunters to provide insights into the character and importance of candidate fit and skill for the selection of a broad range of white-collar employees. Headhunters suggest that the fit of a job candidate is assessed at two levels, one corresponding with a general compatibility with organization-level norms, culture, and strategy, the other corresponding more closely with traits and characteristics of the person or persons with whom the job candidate actually interviews. Skill—a factor which is largely neglected by those who tout the importance of fit—also plays an important and independent role in employee selection. Stalls that influence the selection of employees from a pool of candidates tend to be highly specific if not idiosyncratic, and take the form of what headhunters call hot buttons. We conclude by discussing the conceptualization, causes, and implications of fit; we also consider how the importance of fit and hot buttons challenges the explanatory logic of standard accounts of labor-market success. 相似文献
230.
Linney GE 《Physician executive》1996,22(7):24-25
Are you prepared to ride the waves of change? Will you be ready when the pink slip arrives? Health care executives who can jump a little higher and run a little faster will go further in the draft. Those of you who are prepared for change will always be appealing to recruiters and prospective employers. How can you ride these turbulent waves and not capsize? This article explores some suggestions for positioning yourself: Proper positioning with the inevitable changes in mind will help you move your career in a forward direction. 相似文献