全文获取类型
收费全文 | 25903篇 |
免费 | 675篇 |
国内免费 | 1篇 |
专业分类
管理学 | 3801篇 |
民族学 | 96篇 |
人才学 | 1篇 |
人口学 | 2505篇 |
丛书文集 | 97篇 |
教育普及 | 2篇 |
理论方法论 | 2263篇 |
现状及发展 | 1篇 |
综合类 | 344篇 |
社会学 | 12215篇 |
统计学 | 5254篇 |
出版年
2021年 | 150篇 |
2020年 | 374篇 |
2019年 | 515篇 |
2018年 | 637篇 |
2017年 | 852篇 |
2016年 | 639篇 |
2015年 | 474篇 |
2014年 | 635篇 |
2013年 | 4177篇 |
2012年 | 853篇 |
2011年 | 816篇 |
2010年 | 597篇 |
2009年 | 523篇 |
2008年 | 566篇 |
2007年 | 626篇 |
2006年 | 587篇 |
2005年 | 578篇 |
2004年 | 525篇 |
2003年 | 491篇 |
2002年 | 549篇 |
2001年 | 685篇 |
2000年 | 688篇 |
1999年 | 600篇 |
1998年 | 448篇 |
1997年 | 412篇 |
1996年 | 426篇 |
1995年 | 394篇 |
1994年 | 372篇 |
1993年 | 369篇 |
1992年 | 457篇 |
1991年 | 409篇 |
1990年 | 384篇 |
1989年 | 382篇 |
1988年 | 365篇 |
1987年 | 321篇 |
1986年 | 321篇 |
1985年 | 362篇 |
1984年 | 362篇 |
1983年 | 355篇 |
1982年 | 303篇 |
1981年 | 255篇 |
1980年 | 236篇 |
1979年 | 278篇 |
1978年 | 247篇 |
1977年 | 226篇 |
1976年 | 194篇 |
1975年 | 212篇 |
1974年 | 166篇 |
1973年 | 163篇 |
1971年 | 133篇 |
排序方式: 共有10000条查询结果,搜索用时 578 毫秒
61.
We define a class of count distributions which includes the Poisson as well as many alternative count models. Then the empirical probability generating function is utilized to construct a test for the Poisson distribution, which is consistent against this class of alternatives. The limit distribution of the test statistic is derived in case of a general underlying distribution, and efficiency considerations are addressed. A simulation study indicates that the new test is comparable in performance to more complicated omnibus tests. 相似文献
62.
63.
The theory of incapacitation involves reducing an offender's ability or capacity to commit further crimes. Capital punishment accomplishes this goal. An executed murderer never murders again. However, we do not execute all murderers, only capital murderers. This policy produces several research questions. Do capital murderers present a special risk to society? Are capital murderers more likely to murder or commit other violent crimes again than other murderers or the average citizen? To answer these questions, many states require a prediction of future dangerousness of a newly convicted murderer. To what extent has the judgment of future dangerousness matched actuarial data of subsequent murders and serious crimes? Using a secondary analysis, this investigation attempted to assemble available data of postconviction dangerousness of death sentenced capital murderers to create a more comprehensive actuarial account of subsequent dangerousness and to present the data in a common format used by the Federal Bureau of Investigation and the Bureau of Justice Statistics. Across 14 studies identified with relevant data, there were 13 instances of subsequent murder and 462 serious crime or prison rule violations. 相似文献
64.
Two habituation experiments were conducted to investigate how 4‐month‐old infants perceive partly occluded shapes. In the first experiment, we presented a simple, partly occluded shape to the infants until habituation was reached. Then we showed either a probable completion (one that would be predicted on the basis of both local and global cues) or an improbable completion. Longer looking times were found for the improbably completed shape (compared to probable and control conditions), suggesting that the probable shape was perceived during partial occlusion. In the second experiment, infants were habituated to more ambiguous partly occluded shapes, where local and global cues would result in different completions. For adults, the percept of these shapes is usually dominated by global influences. However, after habituation the infants looked longer at the globally completed shapes. These results suggest that by the age of 4 months, infants are able to infer the perceptual completion of partly occluded shapes, but for more ambiguous shapes, this completion seems to be dominated by local influences. 相似文献
65.
Stephanie M. Pickle Timothy J. Robinson Jeffrey B. Birch Christine M. Anderson-Cook 《Journal of statistical planning and inference》2008
Parameter design or robust parameter design (RPD) is an engineering methodology intended as a cost-effective approach for improving the quality of products and processes. The goal of parameter design is to choose the levels of the control variables that optimize a defined quality characteristic. An essential component of RPD involves the assumption of well estimated models for the process mean and variance. Traditionally, the modeling of the mean and variance has been done parametrically. It is often the case, particularly when modeling the variance, that nonparametric techniques are more appropriate due to the nature of the curvature in the underlying function. Most response surface experiments involve sparse data. In sparse data situations with unusual curvature in the underlying function, nonparametric techniques often result in estimates with problematic variation whereas their parametric counterparts may result in estimates with problematic bias. We propose the use of semi-parametric modeling within the robust design setting, combining parametric and nonparametric functions to improve the quality of both mean and variance model estimation. The proposed method will be illustrated with an example and simulations. 相似文献
66.
67.
Objective. The risk compensation hypothesis suggests that drivers enjoying greater safety will drive more recklessly and thereby impose greater risks on nonoccupants. We provide a test of the risk compensation hypothesis in the context of state seatbelt laws and belt use rates. Methods. Fixed‐effects models with policy and demographic variables are estimated using annual state data from 1985 to 2002 to test the effect of seatbelt laws and seatbelt use rates on logged fatality rates for occupants, pedestrians, motorcyclists, and all nonoccupants in separate models. Results. Contrary to the risk compensation hypothesis, the results indicate that both occupants and nonoccupants enjoy greater safety due to state mandatory use laws and increased safety belt use rates. Conclusion. Overall, seatbelt laws and the higher belt use these laws induce do not increase nonoccupant risk exposure. If anything, these laws and the accompanying increase in belt use result in safer driving behavior. 相似文献
68.
The 1998 Korean Survey of Family Income and Expenditures was used to examine the overall consumption and saving behavior of Korean baby boomers and compared the differences in consumption and saving behavior between older and younger boomers. The t -test results indicated that the younger boomers allocated a significantly higher percentage of their expenditures on food away from home, household appliances, transportation and communication than did the older boomers, whereas the older boomers spent higher amounts and allocated larger budget shares on their children's education than did the younger boomers. The results of Ordinary Least-Squares (OLS) regression analysis showed that, holding other factors constant, older boomers not only spent significantly more in the total consumption expenditures and education expenditures, but older boomers also saved significantly less than did younger boomers. 相似文献
69.
Craig J. Thompson 《The Sociological quarterly》2003,44(1):81-107
Social critics of the natural health movement charge that it indoctrinates consumers in a therapeutic consumerist ideology. This "dominated consumer" thesis ignores that socially situated individuals must negotiate a plethora of institutionally specific power structures aiming to classify and govern their identities. Accordingly, resistance toward specific institutional constructions of identity can be produced through marketplace ideologies. I explore this understudied ideological effect by analyzing the narratives of women who are using natural health alternatives to resist their ascribed medico-administrative identities. Natural health's therapeutic ideology enables these women to contest the degenerative implications of their medical diagnoses and, conversely, to reconstruct their chronic illnesses as an opportunity for discovering their inner regenerative potential and expanding their spiritual horizons. This analysis has implications for prior studies suggesting that resistance toward the technocratic and bureaucratic aspects of conventional medicine exemplifies a Foucauldian "care of the self." I argue that a postmodern adaptation of Foucauldian theory is needed to address the complex interrelationships among the care of the self, medical consumerism, and the therapeutic ideology of the natural health marketplace. 相似文献
70.
Zhu Carolyn W. Moore Michael J. Clipp Elizabeth C. 《Review of Economics of the Household》2003,1(1-2):59-76
Informal caregivers of individuals with Alzheimer's disease spend a considerable amount of time providing care. In this paper, we use Grossman's health production and Becker's time allocation models to develop a model of informal care provision to elderly dementia patients. In our model, time inputs produce caregiving services, which provides utility to the caregiver, but reduces leisure. We assume that time is less productive of services on the margin as the disease progresses. In this framework, an increase in patients' disease severity does not necessarily increase informal caregiver time input. The cost of formal care establishes a reservation price for informal caregiving. When the costs of informal caregiving rise above this reservation level, the patient is institutionalized. We test empirically the effect of deterioration in the patients' condition, proxied by both disease severity and dementia problem behavior, on informal caregiving time. We find that dementia-related problem behaviors and functional limitations significantly increase inputs of informal caregiving time. Patients' problem behavior exerts a modifying effect on functional limitations, and patients' comorbidities have no effect on informal caregiving time. 相似文献