首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   12896篇
  免费   252篇
财政金融   2407篇
工业经济   979篇
计划管理   2097篇
经济学   2659篇
综合类   99篇
运输经济   81篇
旅游经济   252篇
贸易经济   1997篇
农业经济   594篇
经济概况   1949篇
邮电经济   34篇
  2020年   128篇
  2019年   199篇
  2018年   229篇
  2017年   241篇
  2016年   248篇
  2015年   181篇
  2014年   277篇
  2013年   1253篇
  2012年   378篇
  2011年   384篇
  2010年   327篇
  2009年   348篇
  2008年   359篇
  2007年   307篇
  2006年   278篇
  2005年   253篇
  2004年   211篇
  2003年   240篇
  2002年   235篇
  2001年   228篇
  2000年   233篇
  1999年   256篇
  1998年   225篇
  1997年   209篇
  1996年   195篇
  1995年   187篇
  1994年   180篇
  1993年   213篇
  1992年   193篇
  1991年   192篇
  1990年   164篇
  1989年   174篇
  1988年   155篇
  1987年   145篇
  1986年   143篇
  1985年   253篇
  1984年   240篇
  1983年   219篇
  1982年   199篇
  1981年   192篇
  1980年   205篇
  1979年   198篇
  1978年   162篇
  1977年   179篇
  1976年   144篇
  1975年   135篇
  1974年   125篇
  1973年   128篇
  1971年   93篇
  1970年   94篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
191.
This paper uses input-output analysis to measure the impact of oil supply bases and oil construction on the economy of Shetland. The output, income and employment created in each local industry by oil activities is measured. Oil industry multipliers are derived. Possible negative effects of oil on the local economy are considered. Finally, a forecast is made of the impact of oil on the Shetland economy in 1985.  相似文献   
192.
Dr. H. Vogt 《Metrika》1978,25(1):49-58
Summary If 1, 2,..., n and 1, 2,..., –1 are two ordered samples from a population with continuous distribution functionF(x), then the points ( r ,r/n),r=1, 2,..., n–1 provide a better approximation ofF(x) than the points ( r ,r/n),r=1, 2,..., n, in the following sense:A maximal upper deviation and a maximal lower deviation of more theny have — contrary to the points ( r ,r/n) — equal probability for anyy0, if we deal with the points ( r ,r/n). This probability is at least for ally in the interval , 1 less than the probability for a maximal upper deviation of more thany in the case of the points ( r ,r/n). This is shown by a comparison of the Smirnow-Birnbaum-Tingey — formula with an analogous formula for the maximal one-sided deviations of the points( r ,r/n).  相似文献   
193.
Counternarcotics interdiction efforts have traditionally relied on historically determined sorting criteria or “best guess” to find and classify suspected smuggling traffic. We present a more quantitative approach which incorporates customized database applications, graphics software and statistical modeling techniques to develop forecasting and classification models. Preliminary results show that statistical methodology can improve interdiction rates and reduce forecast error. The idea of predictive modeling is thus gaining support in the counterdrug community. The problem is divided into sea, air and land forecasting, only part of which will be addressed here. The maritime problem is solved using multiple regression in lieu of multivariate time series. This model predicts illegal boat counts by behavior and geographic region. We developed support software to present the forecasts and to automate the process of performing periodic model updates. During the period, the model was in use at. Coast Guard Headquarters. Because of deterrence provided by improved intervention, the vessel seizure rate declined from 1 every 36 hours to 1 every 6 months. Due in part to the success of the sea model, the maritime movement of marijuana has ceased to be a major threat. The air problem is more complex, and required us to locally design data collection and display software. Intelligence analysts are using a customized relational database application with a map overlay to perform visual pattern recognition of smuggling routes. We are solving the modeling portion of the air problem using multiple regression for regional forecasts of traffic density, and discriminant analysis to develop tactical models that classify “good guys” and “bad guys”. The air models are still under development, but we discuss some modeling considerations and preliminary results. The land problem is even more difficult, and data collection is still in progress.  相似文献   
194.
Summary Pseudo Bayesian estimators for the variance components based on Jeffrey’s Rule are derived for the mixed balanced incomplete block design and are compared with the usual analysis of variance estimators in terms of mean squared error (MSE) efficiency. Numerical results show that Pseudo-Bayesian estimators are more efficient in numerical results.  相似文献   
195.
Corporate mergers possibly enhance the labor negotiation advantage of employers. This study investigates the association between wage levels and merger activity to test the employer bargaining strength hypothesis. The results indicate significantly lower union wages as a consequence of merging. Merger activity, however, does not influence wage levels of non-union workers. These findings are supportive of the employer bargaining strength hypothesis.  相似文献   
196.
197.
In a course in elementary statistics for psychology students using criterion-referenced achievement tests, the total test score, based on dichotomously scored items, was used for classifying students into those who passed and those who failed. The score on a test is considered as depending on a latent variable; it is assumed that the students can be dichotomized into the categories “mastery” (with scores on the latent variable above a cutting score), and “no mastery” (with scores below the cutting score on the latent variable). Two problems are considered: (a) How many students are classified incorrectly? Using the binomial error model a procedure is described for computing the classification proportions: p(mastery, passed), p(mastery, failed), p(no mastery, passed), and p(no mastery, failed), (b) What is the optimal cutting score on a test? Using a loss function a procedure for computing the optimal curring score is described.  相似文献   
198.
Poly-t densities are defined by the property that their kernel is a product, or ratio of products, of Student-t kernels. These multivariate densities arise as Bayesian posterior densities for regression coefficients, under a surprising variety of specifications for the prior density and the data generating process. Although no analytical expression exists for the integrating constant and moments of these densities, these parameters are obtained through numerical integration in a number of dimensions given by the number of Student-t kernels in the numerator, minus one. The paper reviews how poly-t densities arise in regression analysis, and summarizes the results obtained for a number of models.  相似文献   
199.
Elements of tabellology.
An outline of a system for constructing tables is presented, exemplified by a set of tables for a simple Establishments Census.  相似文献   
200.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号