全文获取类型
收费全文 | 28204篇 |
免费 | 677篇 |
国内免费 | 3篇 |
专业分类
管理学 | 3808篇 |
民族学 | 120篇 |
人才学 | 3篇 |
人口学 | 2494篇 |
丛书文集 | 134篇 |
教育普及 | 3篇 |
理论方法论 | 2485篇 |
综合类 | 289篇 |
社会学 | 14033篇 |
统计学 | 5515篇 |
出版年
2023年 | 137篇 |
2021年 | 137篇 |
2020年 | 374篇 |
2019年 | 508篇 |
2018年 | 649篇 |
2017年 | 869篇 |
2016年 | 625篇 |
2015年 | 488篇 |
2014年 | 648篇 |
2013年 | 5253篇 |
2012年 | 827篇 |
2011年 | 764篇 |
2010年 | 611篇 |
2009年 | 536篇 |
2008年 | 619篇 |
2007年 | 616篇 |
2006年 | 623篇 |
2005年 | 600篇 |
2004年 | 502篇 |
2003年 | 472篇 |
2002年 | 516篇 |
2001年 | 677篇 |
2000年 | 656篇 |
1999年 | 618篇 |
1998年 | 467篇 |
1997年 | 407篇 |
1996年 | 465篇 |
1995年 | 465篇 |
1994年 | 480篇 |
1993年 | 455篇 |
1992年 | 490篇 |
1991年 | 504篇 |
1990年 | 514篇 |
1989年 | 446篇 |
1988年 | 486篇 |
1987年 | 416篇 |
1986年 | 392篇 |
1985年 | 429篇 |
1984年 | 451篇 |
1983年 | 390篇 |
1982年 | 319篇 |
1981年 | 263篇 |
1980年 | 267篇 |
1979年 | 318篇 |
1978年 | 270篇 |
1977年 | 225篇 |
1976年 | 200篇 |
1975年 | 184篇 |
1974年 | 181篇 |
1973年 | 160篇 |
排序方式: 共有10000条查询结果,搜索用时 640 毫秒
841.
Christopher S. Withers 《Statistics》2013,47(1):159-166
H. Kres Statistisehe Tafeln zur multlvariaten Analysis. Springer-Verlag, Berlin- Heidel-berg-New York 1975, XVIII, 431 S., 26 Tab., DM 48. D. Rasch: Einführung in die mathematische Statistik - WahrscheinUcllkeitsrechnung und Grundlagen der mathematlsehan Statistlk. VEB Deutscher Verlag delr Wissenschaften, Berlin 1976, 371 S., 37 Abb., 46 'I'ab., 40,– M. D. Rasch: Einführung in die muthematisehe Statlstik - II .Anweuduugen, VEB Deutscher Verlag der Wissenschaften, Berlin 1976. Donald L. Snyder: Random Point Processes. -JohnWiley &; Sons, New York 1975,485 S. 相似文献
842.
The performance of the balanced half-sample, jackknife and linearization methods for estimating the variance of the combined ratio estimate is studied by means of a computer simulation using artificially generated non-normally distributed populations. The results of this investigation demonstrate that the variance estimates for the combined ratio estimate may be highly biased and unstable when the underlying distributions are non-normal. This is particularly true when the number of observations available from each stratum is small. The jack- 相似文献
843.
A two-phase approach is used to examine the impact of job scheduling rules and tool selection policies for a dynamic job shop system in a tool-shared, flexible manufacturing environment. The first phase develops a generalized simulation model and analyses 'simple' job scheduling rules and tool selection policies under various operating scenarios. The results from this investigation are then used to develop and analyse various bi-criteria rules in the second phase of this study. The results show that the scheduling rules have the most significant impact on system performance, particularly at high shop load levels. Tool selection policies affect some of the performance measures, most notably, proportion of tardy jobs, to a lesser degree. Higher machine utilizations can be obtained at higher tool duplication levels but at the expense of increased tooling costs and lower tool utilization. The results also show that using different processing time distributions may have a significant impact on shop performance. 相似文献
844.
845.
Research shows that those with greater social capital enjoy better physical and mental health. The current study illuminates a paradox of social capital which may afflict those involved in traumatic events. Several years of survey data reveal a dynamic picture of the link between social capital and stress following Hurricane Katrina. Results reveal that initially after Katrina, those who were more socially embedded carried the greatest load with respect to helping the displaced population, thus experiencing more stress. But over time, the most socially-involved then snapped back from their stressful experiences more rapidly than isolates. This confirms that over the course of stressful events, social involvement first exposes people to more stress, but as time passes, provides them a significant buffer against negative psychosocial experiences. 相似文献
846.
AbstractWe propose a cure rate survival model by assuming that the number of competing causes of the event of interest follows the negative binomial distribution and the time to the event of interest has the Birnbaum-Saunders distribution. Further, the new model includes as special cases some well-known cure rate models published recently. We consider a frequentist analysis for parameter estimation of the negative binomial Birnbaum-Saunders model with cure rate. Then, we derive the appropriate matrices for assessing local influence on the parameter estimates under different perturbation schemes. We illustrate the usefulness of the proposed model in the analysis of a real data set from the medical area. 相似文献
847.
This article develops the locally uniformly most powerful unbiased Lagrange multiplier test of normality of regression disturbances within the family of power exponential distributions. The small sample power properties of the test are compared in a Monte Carlo study with 6 well-known tests across 12 alternative nonnormal distributions. In addition, the finite sample power properties for nonnormal alternatives within the power exponential family are summarized by estimating response surfaces. The results suggest that the proposed text is computationally convenient and possesses relatively attractive power properties even against alternatives outside the power exponential family. 相似文献
848.
Mbilinyi LF Neighbors C Walker DD Roffman RA Zegree J Edleson J O'Rourke A 《Research on social work practice》2011,21(1):43-56
OBJECTIVE: To preliminarily evaluate telephone-delivered motivational enhancement therapy (MET) in motivating unadjudicated and nontreatment seeking intimate partner violence (IPV) perpetrators, who also use substances, to self-refer into treatment. METHOD: 124 adult men were recruited via a multimedia marketing campaign and were randomly assigned to the intervention (MET) or comparison group following a baseline assessment. Participants in the MET condition received a personalized feedback report on their IPV and substance-use behaviors, consequences, and social norms beliefs. RESULTS: Results supported the likely effectiveness of MET in short-term reduction of IPV behavior, increasing motivation for treatment seeking, and changing perceived norms for IPV and substance abuse (SA). CONCLUSIONS: Applications for brief MET interventions to facilitate voluntary treatment entry among substance-using IPV perpetrators are discussed. 相似文献
849.
Robert?Joseph?TaylorEmail authorView authors OrcID profile Dawne?M.?Mouzon Ann?W.?Nguyen Linda?M.?Chatters 《Race and social problems》2016,8(4):326-339
This study examined reciprocal support networks involving extended family, friends and church members among African Americans. Our analysis examined specific patterns of reciprocal support (i.e., received only, gave only, both gave and received, neither gave or received), as well as network characteristics (i.e., contact and subjective closeness) as correlates of reciprocal support. The analysis is based on the African American subsample of the National Survey of American Life. Overall, our findings indicate that African Americans are very involved in reciprocal support networks with their extended family, friends and church members. Respondents were most extensively involved in reciprocal supports with extended family members, followed closely by friends and church networks. Network characteristics (i.e., contact and subjective closeness) were significantly and consistently associated with involvement with reciprocal support exchanges for all three networks. These and other findings are discussed in detail. This study complements previous work on the complementary roles of family, friend and congregational support networks, as well as studies of racial differences in informal support networks. 相似文献
850.
Ralph S. J. Koijen Motohiro Yogo 《Econometrica : journal of the Econometric Society》2016,84(3):1265-1287
Life insurers use reinsurance to move liabilities from regulated and rated companies that sell policies to shadow reinsurers, which are less regulated and unrated off‐balance‐sheet entities within the same insurance group. U.S. life insurance and annuity liabilities ceded to shadow reinsurers grew from $11 billion in 2002 to $364 billion in 2012. Life insurers using shadow insurance, which capture half of the market share, ceded 25 cents of every dollar insured to shadow reinsurers in 2012, up from 2 cents in 2002. By relaxing capital requirements, shadow insurance could reduce the marginal cost of issuing policies and thereby improve retail market efficiency. However, shadow insurance could also reduce risk‐based capital and increase expected loss for the industry. We model and quantify these effects based on publicly available data and plausible assumptions. 相似文献