全文获取类型
收费全文 | 5059篇 |
免费 | 231篇 |
国内免费 | 25篇 |
专业分类
管理学 | 472篇 |
劳动科学 | 1篇 |
民族学 | 23篇 |
人才学 | 1篇 |
人口学 | 147篇 |
丛书文集 | 116篇 |
理论方法论 | 167篇 |
综合类 | 1132篇 |
社会学 | 367篇 |
统计学 | 2889篇 |
出版年
2024年 | 15篇 |
2023年 | 66篇 |
2022年 | 56篇 |
2021年 | 79篇 |
2020年 | 128篇 |
2019年 | 176篇 |
2018年 | 220篇 |
2017年 | 285篇 |
2016年 | 199篇 |
2015年 | 178篇 |
2014年 | 221篇 |
2013年 | 973篇 |
2012年 | 379篇 |
2011年 | 257篇 |
2010年 | 207篇 |
2009年 | 210篇 |
2008年 | 204篇 |
2007年 | 216篇 |
2006年 | 167篇 |
2005年 | 166篇 |
2004年 | 138篇 |
2003年 | 115篇 |
2002年 | 89篇 |
2001年 | 83篇 |
2000年 | 79篇 |
1999年 | 69篇 |
1998年 | 65篇 |
1997年 | 46篇 |
1996年 | 24篇 |
1995年 | 22篇 |
1994年 | 30篇 |
1993年 | 18篇 |
1992年 | 23篇 |
1991年 | 19篇 |
1990年 | 15篇 |
1989年 | 9篇 |
1988年 | 16篇 |
1987年 | 7篇 |
1986年 | 4篇 |
1985年 | 9篇 |
1984年 | 6篇 |
1983年 | 10篇 |
1982年 | 8篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有5315条查询结果,搜索用时 156 毫秒
11.
成都市民旅游感应空间研究 总被引:1,自引:0,他引:1
旅游感应强度是研究旅游感应空间的一个角度。通过对《成都晚报》“旅游”专刊最近 6年的统计 ,得到全国 34个省级行政区及四川省内分地区作为旅游目的地的出现频次 ,以此频次来表征成都市民对国内及省内旅游目的地的感应强度。利用感应强度从省际和省内不同尺度揭示了成都市民旅游感应空间的特点 ,并发现旅游感应空间的一些新特征 相似文献
12.
焦凤梅 《湖北民族学院学报(哲学社会科学版)》2002,20(5):85-88
20世纪90年代在社会民主主义复兴的过程中,英国和法国由于竞选方式、政策策略等一系列方面存在显著差别,被认为是社会民主主义复兴的两种典型模式,对英国道路与法国道路的相同之处和不同之处进行比较,说明二者存在共同性和差异性的原因。 相似文献
13.
Mark S. Pearce Heather O. Dickinson Murray Aitkin Louise Parker 《Journal of the Royal Statistical Society. Series A, (Statistics in Society)》2002,165(3):523-548
Summary. This study investigates whether there was evidence of increasing risk of still-birth with increasing paternal exposure to ionizing radiation received during employment at the Sellafield nuclear installation before the child was conceived. A significant positive association is found between the total paternal preconceptional exposure to external ionizing radiation and the risk of still-birth (after adjustment for year of birth, social class, birth order and paternal age, odds ratio at 100 mSv 1.24 (95% confidence interval 1.04–1.45)). A summary of the principal scientific findings of this study has been published in the Lancet . This paper describes in detail the statistical methods that were used in the investigation and presents the results in full. 相似文献
14.
《Australian & New Zealand Journal of Statistics》2002,44(4):505-506
Books reviewed:
M Hollander and D Wolfe, Nonparametric Statistical Methods
T Leonard and J.S.J Hsu, Bayesian Methods 相似文献
M Hollander and D Wolfe, Nonparametric Statistical Methods
T Leonard and J.S.J Hsu, Bayesian Methods 相似文献
15.
Diane Hope Weixing Zhu Corinna Gries Jacob Oleson Jason Kaye Nancy B. Grimm Lawrence A. Baker 《Urban Ecosystems》2005,8(3-4):251-273
We explored variations in inorganic soil nitrogen (N) concentrations across metropolitan Phoenix, Arizona, and the surrounding
desert using a probability-based synoptic survey. Data were examined using spatial statistics on the entire region, as well
as for the desert and urban sites separately. Concentrations of both NO3-N and NH4-N were markedly higher and more heterogeneous amongst urban compared to desert soils. Regional variation in soil NO3-N concentration was best explained by latitude, land use history, population density, along with percent cover of impervious
surfaces and lawn, whereas soil NH4-N concentrations were related to only latitude and population density. Within the urban area, patterns in both soil NO3-N and NH4-N were best predicted by elevation, population density and type of irrigation in the surrounding neighborhood. Spatial autocorrelation
of soil NO3-N concentrations explained 49% of variation among desert sites but was absent between urban sites. We suggest that inorganic
soil N concentrations are controlled by a number of ‘local’ or ‘neighborhood’ human-related drivers in the city, rather than
factors related to an urban-rural gradient. 相似文献
16.
Modelling daily multivariate pollutant data at multiple sites 总被引:7,自引:1,他引:6
Gavin Shaddick Jon Wakefield 《Journal of the Royal Statistical Society. Series C, Applied statistics》2002,51(3):351-372
Summary. This paper considers the spatiotemporal modelling of four pollutants measured daily at eight monitoring sites in London over a 4-year period. Such multiple-pollutant data sets measured over time at multiple sites within a region of interest are typical. Here, the modelling was carried out to provide the exposure for a study investigating the health effects of air pollution. Alternative objectives include the design problem of the positioning of a new monitoring site, or for regulatory purposes to determine whether environmental standards are being met. In general, analyses are hampered by missing data due, for example, to a particular pollutant not being measured at a site, a monitor being inactive by design (e.g. a 6-day monitoring schedule) or because of an unreliable or faulty monitor. Data of this type are modelled here within a dynamic linear modelling framework, in which the dependences across time, space and pollutants are exploited. Throughout the approach is Bayesian, with implementation via Markov chain Monte Carlo sampling. 相似文献
17.
Sets of relatively short time series arise in many situations. One aspect of their analysis may be the detection of outlying
series. We examine the performance of standard normal outlier tests applied to the means, or to simple functions of the means,
of AR(1) series, not necessarily of equal lengths. Although unequal lengths of series implies that the means have unequal
variances, that are only known approximately, it is shown that nominal significance levels hold good under most circumstances.
Thus a standard outlier test can usefully be applied, avoiding the complication of estimating the time series' parameters.
The test's power is affected by unequal lengths, being higher when the slippage occurs in one of the longer series 相似文献
18.
Craig H. Mallinckrodt Christopher J. Kaiser John G. Watkin Michael J. Detke Geert Molenberghs Raymond J. Carroll 《Pharmaceutical statistics》2004,3(3):171-186
The last observation carried forward (LOCF) approach is commonly utilized to handle missing values in the primary analysis of clinical trials. However, recent evidence suggests that likelihood‐based analyses developed under the missing at random (MAR) framework are sensible alternatives. The objective of this study was to assess the Type I error rates from a likelihood‐based MAR approach – mixed‐model repeated measures (MMRM) – compared with LOCF when estimating treatment contrasts for mean change from baseline to endpoint (Δ). Data emulating neuropsychiatric clinical trials were simulated in a 4 × 4 factorial arrangement of scenarios, using four patterns of mean changes over time and four strategies for deleting data to generate subject dropout via an MAR mechanism. In data with no dropout, estimates of Δ and SEΔ from MMRM and LOCF were identical. In data with dropout, the Type I error rates (averaged across all scenarios) for MMRM and LOCF were 5.49% and 16.76%, respectively. In 11 of the 16 scenarios, the Type I error rate from MMRM was at least 1.00% closer to the expected rate of 5.00% than the corresponding rate from LOCF. In no scenario did LOCF yield a Type I error rate that was at least 1.00% closer to the expected rate than the corresponding rate from MMRM. The average estimate of SEΔ from MMRM was greater in data with dropout than in complete data, whereas the average estimate of SEΔ from LOCF was smaller in data with dropout than in complete data, suggesting that standard errors from MMRM better reflected the uncertainty in the data. The results from this investigation support those from previous studies, which found that MMRM provided reasonable control of Type I error even in the presence of MNAR missingness. No universally best approach to analysis of longitudinal data exists. However, likelihood‐based MAR approaches have been shown to perform well in a variety of situations and are a sensible alternative to the LOCF approach. MNAR methods can be used within a sensitivity analysis framework to test the potential presence and impact of MNAR data, thereby assessing robustness of results from an MAR method. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
19.
Merging information for semiparametric density estimation 总被引:1,自引:0,他引:1
Konstantinos Fokianos 《Journal of the Royal Statistical Society. Series B, Statistical methodology》2004,66(4):941-958
Summary. The density ratio model specifies that the likelihood ratio of m −1 probability density functions with respect to the m th is of known parametric form without reference to any parametric model. We study the semiparametric inference problem that is related to the density ratio model by appealing to the methodology of empirical likelihood. The combined data from all the samples leads to more efficient kernel density estimators for the unknown distributions. We adopt variants of well-established techniques to choose the smoothing parameter for the density estimators proposed. 相似文献
20.
Maximum likelihood estimation and goodness-of-fit techniques are used within a competing risks framework to obtain maximum likelihood estimates of hazard, density, and survivor functions for randomly right-censored variables. Goodness-of- fit techniques are used to fit distributions to the crude lifetimes, which are used to obtain an estimate of the hazard function, which, in turn, is used to construct the survivor and density functions of the net lifetime of the variable of interest. If only one of the crude lifetimes can be adequately characterized by a parametric model, then semi-parametric estimates may be obtained using a maximum likelihood estimate of one crude lifetime and the empirical distribution function of the other. Simulation studies show that the survivor function estimates from crude lifetimes compare favourably with those given by the product-limit estimator when crude lifetimes are chosen correctly. Other advantages are discussed. 相似文献