全文获取类型
收费全文 | 19447篇 |
免费 | 485篇 |
专业分类
管理学 | 2636篇 |
民族学 | 81篇 |
人才学 | 3篇 |
人口学 | 1740篇 |
丛书文集 | 104篇 |
教育普及 | 2篇 |
理论方法论 | 1795篇 |
综合类 | 415篇 |
社会学 | 9303篇 |
统计学 | 3853篇 |
出版年
2023年 | 94篇 |
2021年 | 114篇 |
2020年 | 273篇 |
2019年 | 340篇 |
2018年 | 401篇 |
2017年 | 592篇 |
2016年 | 469篇 |
2015年 | 363篇 |
2014年 | 423篇 |
2013年 | 3278篇 |
2012年 | 656篇 |
2011年 | 521篇 |
2010年 | 372篇 |
2009年 | 383篇 |
2008年 | 444篇 |
2007年 | 441篇 |
2006年 | 343篇 |
2005年 | 489篇 |
2004年 | 427篇 |
2003年 | 403篇 |
2002年 | 438篇 |
2001年 | 489篇 |
2000年 | 452篇 |
1999年 | 459篇 |
1998年 | 331篇 |
1997年 | 307篇 |
1996年 | 319篇 |
1995年 | 284篇 |
1994年 | 289篇 |
1993年 | 271篇 |
1992年 | 340篇 |
1991年 | 332篇 |
1990年 | 309篇 |
1989年 | 304篇 |
1988年 | 288篇 |
1987年 | 278篇 |
1986年 | 280篇 |
1985年 | 279篇 |
1984年 | 284篇 |
1983年 | 292篇 |
1982年 | 227篇 |
1981年 | 198篇 |
1980年 | 197篇 |
1979年 | 228篇 |
1978年 | 200篇 |
1977年 | 166篇 |
1976年 | 143篇 |
1975年 | 156篇 |
1974年 | 135篇 |
1973年 | 126篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
Stuart Barber Guy P. Nason 《Journal of the Royal Statistical Society. Series B, Statistical methodology》2004,66(4):927-939
Summary. Wavelet shrinkage is an effective nonparametric regression technique, especially when the underlying curve has irregular features such as spikes or discontinuities. The basic idea is simple: take the discrete wavelet transform of data consisting of a signal corrupted by noise; shrink or remove the wavelet coefficients to remove the noise; then invert the discrete wavelet transform to form an estimate of the true underlying curve. Various researchers have proposed increasingly sophisticated methods of doing this by using real-valued wavelets. Complex-valued wavelets exist but are rarely used. We propose two new complex-valued wavelet shrinkage techniques: one based on multiwavelet style shrinkage and the other using Bayesian methods. Extensive simulations show that our methods almost always give significantly more accurate estimates than methods based on real-valued wavelets. Further, our multiwavelet style shrinkage method is both simpler and dramatically faster than its competitors. To understand the excellent performance of this method we present a new risk bound on its hard thresholded coefficients. 相似文献
93.
This article aims to bring gender into an even tighter transnational migration focus by broadening and deepening our original framework of “gendered geographies of power,” linking it more directly to existing and emerging scholarship. We examine and highlight previously neglected areas such as the role of the state and the social imaginary in gendering transnational processes and experiences. We identify topics that remain under‐appreciated, under‐researched, and/or under‐theorized. Finally, we initiate a discussion of how a gendered analysis of transnational migration can help bridge this particular research to other gendered transnational processes under study that do not privilege migration. 相似文献
94.
D. R. Cox Man Yu Wong 《Journal of the Royal Statistical Society. Series B, Statistical methodology》2004,66(2):395-400
Summary. Given a large number of test statistics, a small proportion of which represent departures from the relevant null hypothesis, a simple rule is given for choosing those statistics that are indicative of departure. It is based on fitting by moments a mixture model to the set of test statistics and then deriving an estimated likelihood ratio. Simulation suggests that the procedure has good properties when the departure from an overall null hypothesis is not too small. 相似文献
95.
魏晋南北朝是中国古代动乱最多、人民生活最悲惨的时代。战争、动乱使汉王朝“独尊儒术”的旧思想体制大崩溃 ,导致魏晋南北朝时期的古代中国思想最解放、最自由。美学思想和精神的自由 ,酿就了艺术创造精神的勃发 ,因而新的艺术形式、艺术规律应运而生并相互融会贯通。此时的盆景艺术正是在绘画、园林、盆栽、赏石等艺术形式的影响下孕育了自己最初的表现形式和美学规律 ,因此可以说该时期是盆景发展史上的一个重要阶段 相似文献
96.
William R. Shadish Kevin Ragsdale Renita R. Glaser Linda M. Montgomery 《Journal of marital and family therapy》1995,21(4):345-360
This article reviews the major findings from a multiproject meta-analysis of the effects of marital and family therapy (MFT). Across 163 randomized trials, MFT demonstrates moderate, statistically significant, and often clinically significant effects. No orientation is yet demonstrably superior to any other, nor is MFT superior to individual therapy. Cost effectiveness information is scant in these 163 studies, but supportive. Randomized experiments yield very different answers from nonrandomized experimental studies of the effects of MFT, calling into question whether we should mix the two in reviews. We have also found several new differences in the ways that marital therapy (MT) and family therapy (FT) studies are conducted, making them harder to compare. Finally, important questions still exist about whether any psychotherapy, including MFT, yet has sufficient information about how well research generalizes to everyday clinical practice. 相似文献
97.
TESTAMENTARY BEHAVIOR: 总被引:1,自引:0,他引:1
T.P. Schwartz 《The Sociological quarterly》1993,34(2):337-355
Content analysis and qualitative analysis of all 319 last wills that were filed in Providence Probate Court, 1985, revealed that about ten percent of the testators used testamentary material, disinheritance or altruism to express their individuality. About 42 percent of the wills were personalized directly in other ways. Forty-eight percent displayed indirect influences of family, friends and community. Less that ten percent displayed primary influences of attorneys, banks, nursing homes, governments, religions or other organizations. In the light of these findings, while none of the three major theoretical positions on testamentary behavior prevails, the individualist position is manifested more often than is the family-community position. Both of these positions are manifested much more often than is the legalist position.
These findings are related to the work of Emile Durkheim and to contemporary sociological theories of the family, community and law. 相似文献
These findings are related to the work of Emile Durkheim and to contemporary sociological theories of the family, community and law. 相似文献
98.
D. R. Wingo 《Statistical Papers》1993,34(1):271-276
In a recent paper in this journal, Lee, Kapadia and Brock (1980) developed maximum likelihood (ML) methods for estimating the scale parameter of the Rayleigh distribution from doubly censored samples. They reported convergence difficulties in attempting to solve numerically the nonlinear likelihood equation (LE). To mitigate these difficulties, they employed approximations to simplify the LE, but found that the solution of the resulting simplified equation can give rise to parameter estimates of erratic accuracy. We show that the use of approximations to simplify the LE is unnecessary. In fact, under suitable parametric transformation, the log-likelihood function is strictly concave, the ML estimate always exists, is unique and finite. Furthermore, the LE is easy to solve numerically. A numerical example is given to illustrate the computations involved. 相似文献
99.
The authors investigated the prevalence of recurrent pain in a college student sample. Of the 1,564 students surveyed, 467 (29%) indicated that they had experienced recurrent pain at an intensity that was mostly in the mild-to-moderate range. Students who reported having recurrent pain were significantly older and more depressed than students who did not indicate they suffered from recurrent pain. Pain intensity was positively correlated (r = .14) with depression among the students who reported having recurrent pain. Implications of the findings for future research, treatment, and health promotion efforts are discussed. 相似文献
100.
A table is presented for the construction and selection of tightened-normal-tightened sampling scheme of type TNT-(n1, n2;c). Efficiency of TNT-(n1, n2;c) scheme over conventional single and double sampling plans is discussed. 相似文献