全文获取类型
收费全文 | 15080篇 |
免费 | 351篇 |
专业分类
管理学 | 2003篇 |
民族学 | 75篇 |
人才学 | 2篇 |
人口学 | 1301篇 |
丛书文集 | 97篇 |
教育普及 | 2篇 |
理论方法论 | 1394篇 |
综合类 | 361篇 |
社会学 | 7638篇 |
统计学 | 2558篇 |
出版年
2021年 | 81篇 |
2020年 | 216篇 |
2019年 | 251篇 |
2018年 | 291篇 |
2017年 | 435篇 |
2016年 | 337篇 |
2015年 | 260篇 |
2014年 | 307篇 |
2013年 | 2505篇 |
2012年 | 451篇 |
2011年 | 404篇 |
2010年 | 276篇 |
2009年 | 290篇 |
2008年 | 317篇 |
2007年 | 355篇 |
2006年 | 273篇 |
2005年 | 415篇 |
2004年 | 357篇 |
2003年 | 320篇 |
2002年 | 321篇 |
2001年 | 360篇 |
2000年 | 342篇 |
1999年 | 351篇 |
1998年 | 254篇 |
1997年 | 249篇 |
1996年 | 262篇 |
1995年 | 239篇 |
1994年 | 237篇 |
1993年 | 219篇 |
1992年 | 277篇 |
1991年 | 273篇 |
1990年 | 245篇 |
1989年 | 247篇 |
1988年 | 222篇 |
1987年 | 216篇 |
1986年 | 213篇 |
1985年 | 206篇 |
1984年 | 235篇 |
1983年 | 234篇 |
1982年 | 196篇 |
1981年 | 167篇 |
1980年 | 167篇 |
1979年 | 195篇 |
1978年 | 167篇 |
1977年 | 134篇 |
1976年 | 127篇 |
1975年 | 117篇 |
1974年 | 116篇 |
1973年 | 102篇 |
1971年 | 74篇 |
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
881.
In this note, we consider the problem of the existence of adaptive confidence bands in the fixed design regression model, adapting ideas in Hoffmann and Nickl [(2011), ‘On Adaptive Inference and Confidence Bands’, Annals of Statistics, 39, 2383–2409] to the present case. In the course of the proof, we show that sup-norm adaptive estimators exist as well in the regression setting. 相似文献
882.
Between 1970 and 1990, China experiencoed a rapid and sharp fertility decline—from total fertility rates of approximately six births to two. The degree to which Chinese fertility has continued to fall after 1990 is controversial. We use survey data from the 1997 National Population and Reproductive Health Survey and from the 2001 Reproductive Health and Family Planning Survey to document recent trends in Chinese fertility. Our estimates provide further evidence that China's fertility is well below‐replacement level at the turn of the twenty‐first century—with TFR levels of approximately 1.5 children per woman. Trends in parity‐specific cohort fertility by age also suggest below replacement completed fertility for cohorts still in the childbearing years. In the article's second section, we identify key components of low period fertility in order to frame our discussion of two questions: 1) in what ways is Chinese low fertility different from/similar to that in other low‐fertility countries? And 2) what are the likely future trends in Chinese fertility? 相似文献
883.
R. P. Mohanty 《生产规划与管理》2013,24(1):10-13
In this note, the author puts forth some fundamental but generic issues arising from evolving theories and practices of TQM and suggests an agenda for furtherance of research. 相似文献
884.
Owing to high development and acquisition costs, production systems require very detailed analysis for pre-design specifications, and an adjustment in operating philosophies. Detailed simulation models are one of the most important instruments to achieve this goal; normally the simulator must be custom-built, based on an accurate study of the specific industrial problem. The proposed management and economical analysis uses mathematical meta-models obtained from experimental designs produced by the simulator; today the detail level and precision required is very high, so these kinds of meta-model operate very close to their limit. Here we present a new methodology based on artificial neural networks that produces new types of meta-models which can correctly represent complex industrial systems. In this work we propose an application of this methodology together with a detailed analysis of the model development phase to highlight the potential of this instrument. 相似文献
885.
Norman P. Li Lily Patel Daniel Balliet William Tov Christie N. Scollon 《Social indicators research》2011,101(3):391-404
We examined factors related to attitudes toward marriage and the importance of having children in both the US and Singapore.
Path analysis indicated that life dissatisfaction leads to materialism, and both of these factors lead to favorable attitudes
toward marriage, which leads to greater desire for children. Further analysis indicated this model was effective in explaining
the difference in desire for children between Singaporeans and Americans, whereby Singaporeans have lower life satisfaction,
higher materialism, and lower attitudes toward marriage and children. Materialistic standards of success were also related
to the emphasis women placed on potential marriage partners’ earning capacity. As Singaporean women had higher materialistic
standards, they also placed higher emphasis on potential mates’ earning capacity. Results suggest a consideration of psychological
variables such as life satisfaction, materialism, and mate preferences may lead to a better understanding of larger-scale
socioeconomic issues, including low fertility rates among developed East Asian countries. 相似文献
886.
This paper considers five test statistics for comparing the recovery of a rapid growth‐based enumeration test with respect to the compendial microbiological method using a specific nonserial dilution experiment. The finite sample distributions of these test statistics are unknown, because they are functions of correlated count data. A simulation study is conducted to investigate the type I and type II error rates. For a balanced experimental design, the likelihood ratio test and the main effects analysis of variance (ANOVA) test for microbiological methods demonstrated nominal values for the type I error rate and provided the highest power compared with a test on weighted averages and two other ANOVA tests. The likelihood ratio test is preferred because it can also be used for unbalanced designs. It is demonstrated that an increase in power can only be achieved by an increase in the spiked number of organisms used in the experiment. The power is surprisingly not affected by the number of dilutions or the number of test samples. A real case study is provided to illustrate the theory. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
887.
E. Michel‐Kerjan S. Hochrainer‐Stigler H. Kunreuther J. Linnerooth‐Bayer R. Mechler R. Muir‐Wood N. Ranger P. Vaziri M. Young 《Risk analysis》2013,33(6):984-999
Major natural disasters in recent years have had high human and economic costs, and triggered record high postdisaster relief from governments and international donors. Given the current economic situation worldwide, selecting the most effective disaster risk reduction (DRR) measures is critical. This is especially the case for low‐ and middle‐income countries, which have suffered disproportionally more economic and human losses from disasters. This article discusses a methodology that makes use of advanced probabilistic catastrophe models to estimate benefits of DRR measures. We apply such newly developed models to generate estimates for hurricane risk on residential structures on the island of St. Lucia, and earthquake risk on residential structures in Istanbul, Turkey, as two illustrative case studies. The costs and economic benefits for selected risk reduction measures are estimated taking account of hazard, exposure, and vulnerability. We conclude by emphasizing the advantages and challenges of catastrophe model‐based cost‐benefit analyses for DRR in developing countries. 相似文献
888.
R.R. Hocking 《统计学通讯:理论与方法》2013,42(4):983-1010
The purpose of this paper is to describe a simple procedure for the estima-tion of parameters in the unbalanced mixed linear model. There are implications for hypothesis testing and interval estimation, A feature of these estimators is that they are expressed in terms of simple formulas. This has obvious advantages for computations and small sample analysis. In addition, the formulas suggest useful diagnostic procedures for assessing the quality of the data as well as possible defects in the model assumptions. The concepts are illustrated with several examples. Evidence is presented to indicate that, in cases of modest imbalance, these estimators are highly efficient and dominate AOV estimates over most of the parameter space. In cases of more extreme imbalance, the results are qualitatively the same but the estimators are less efficient than the AOV estimators for small values of the parameters. The extension of this method to factorial models with missing cells is not complete. 相似文献
889.
For past two decades many organisations have tried to implement integrated information management systems for better production management based on co-ordination of information and therefore activities of different departments. Although Enterprise Resource Planning systems have been in the market for the past decade, many industries find it difficult to implement such systems due to the amount of work involved in streamlining the documentation, customisation and of high costs reported in implementation. An attempt is made through this paper to propose an integrated model, which can be easily understood by production personnel, with specific emphasis on the textile sector. 相似文献
890.
On-time delivery is the need for customer satisfaction which is a critical factor in the survival of the semiconductor industry. The on-time-delivery performance of the whole semiconductor turnkey service depends on the performance of the back-end factories. Unfortunately, undesirable and inevitable production variations make it difficult to maintain and improve a factory's performance and more objectives such as cycle time, throughput rate and the due-date accuracy need to be simultaneously considered. This paper presents an exception management model in order to compromise the contradicting needs of delivery accuracy, throughput rate and cycle time. The exception model can be divided into three parts: (1) an integrated performance index is proposed to compromise multiple performance measures; (2) an AWDL (available WIP deviation level) determination model is designed to gather proper AWDLs for triggering exceptions and (3) a WIP correction action is proposed to make abnormal WIP levels back to normal levels as soon as possible. To evaluate the proposed WIP exception management model, a simulation model is constructed and experiments are then conducted. The simulation results show that the proposed model helps back-end factories to set proper exception triggering conditions, reduce uncertainty occurrences and achieve better performances on due dates. 相似文献