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   657篇
  免费   27篇
  国内免费   7篇
财政金融   37篇
工业经济   38篇
计划管理   152篇
经济学   123篇
综合类   86篇
运输经济   4篇
旅游经济   21篇
贸易经济   94篇
农业经济   83篇
经济概况   53篇
  2024年   3篇
  2023年   12篇
  2022年   11篇
  2021年   12篇
  2020年   20篇
  2019年   21篇
  2018年   24篇
  2017年   21篇
  2016年   25篇
  2015年   23篇
  2014年   42篇
  2013年   53篇
  2012年   59篇
  2011年   51篇
  2010年   51篇
  2009年   48篇
  2008年   53篇
  2007年   41篇
  2006年   32篇
  2005年   16篇
  2004年   16篇
  2003年   10篇
  2002年   8篇
  2001年   10篇
  2000年   6篇
  1999年   5篇
  1998年   5篇
  1997年   2篇
  1996年   4篇
  1995年   1篇
  1994年   2篇
  1993年   1篇
  1992年   2篇
  1990年   1篇
排序方式: 共有691条查询结果,搜索用时 1 毫秒
71.
随着信息技术在各行各业的普遍应用和其自身的迅速发展,信息技术在各行各业的影响也日益显著,文章就如何有效地把信息技术应用到自来水行业生产调度中,力求达到供水科学调度,生产节能降耗,提出针对调度部门的工作需要进行了调度软件功能的设计开发。  相似文献   
72.
体育教育在学校素质教育中的特殊作用   总被引:2,自引:0,他引:2  
素质教育是整体和长远的教育思想,它的提出标志着我国教育的一大进步,社会各界对实施素质教育已达成共识,学校体育教育是素质教育的重要内容之一。  相似文献   
73.
This paper compares the approximation capabilities of the minflex-Laurents translog and minflex generalized Leontief cost functions with their translog and generalized Leontief counterparts in Monte Carlo experiments. The minflex Laurent specifications generally provided closer approximations to underlying technical and economic parameters. Imposition of nonlinear restrictions on some of the parameters of the minflex Laurent models yielded measurable improvement in estimated elasticities of substitutions, returns to scale, and rates of technical change.The refereeing process of this paper was handled through E. Appelbaum.  相似文献   
74.
The paper is concerned with testing normality in samples of curves and error curves estimated from functional regression models. We propose a general paradigm based on the application of multivariate normality tests to vectors of functional principal components scores. We examine finite sample performance of a number of such tests and select the best performing tests. We apply them to several extensively used functional data sets and determine which can be treated as normal, possibly after a suitable transformation. We also offer practical guidance on software implementations of all tests we study and develop large sample justification for tests based on sample skewness and kurtosis of functional principal component scores.  相似文献   
75.
This paper investigates the reasons why some technologies, defying general expectations and the established models of technological change, may not disappear from the market after having been displaced from their once-dominant status. Our point of departure is that the established models of technological change are not suitable to explain this as they predominantly focus on technological dominance, giving attention to the technologies that display highest performance levels and gain greatest market share. And yet, technological landscapes are rife with technological designs that do not fulfil these conditions. Using the LP record as an empirical case, we propose that the central mechanism at play in the continuing market presence of once-dominant technologies is the recasting of their technological features from the functional-utilitarian to the aesthetic realm, with an additional element concerning communal interaction among users. The findings that emerge from our quantitative textual analysis of over 200,000 posts on a prominent online LP-related discussion forum (between 2002 and 2010) also suggest that the post-dominance technology adopters and users appear to share many key characteristics with the earliest adopters of new technologies, rather than with late-stage adopters which precede them.  相似文献   
76.
Recent years have seen an explosion of activity in the field of functional data analysis (FDA), in which curves, spectra, images and so on are considered as basic functional data units. A central problem in FDA is how to fit regression models with scalar responses and functional data points as predictors. We review some of the main approaches to this problem, categorising the basic model types as linear, non‐linear and non‐parametric. We discuss publicly available software packages and illustrate some of the procedures by application to a functional magnetic resonance imaging data set.  相似文献   
77.
Google Earth在成都市功能分区研究中的应用   总被引:2,自引:0,他引:2  
在历经了20余年的改革发展后,成都市在基础设施建设、产业结构调整和生态环境保护等方面都取得了长足的进步,在政治经济文化发展的同时,城市的用地规模日益扩大,城市功能分区日趋复杂,人地矛盾、功能与形态分区矛盾日渐凸现,城市功能分区已经成为制约城市发展的重要因素之一.为此开展成都市功能分区的研究也愈加重要,利用Google Earth软件提供的在线浏览的高分辨率遥感图像,结合其特有的空间分析和查询功能,探讨成都市的功能区的分区及成因,并对城市功能分区的发展趋势做出预测.  相似文献   
78.
旅游业已经成为中国城乡发展的新动力,在城乡地域功能演化中起到的作用越来越显著。山地丘陵地区在旅游业驱动下,多种地域功能交互重叠,构成了多类型复杂耦合空间,面临着区域可持续发展的模式抉择。本研究以河南鲁山县为例,探讨山地丘陵地区在旅游引导下的城乡一体化发展策略。研究发现:(1)山地丘陵地区的地域功能正在从传统单一的“居住-农业非农业生产”向综合功能的“生态保障-居住-农业非农业生产-休闲文化服务”转变,多类型空间交互特征明显。(2)鲁山县由农业经济主导向旅游经济主导转变,可划分为旅游服务承接平台区、山地生态旅游发展区、特色林业旅游融合区、平原高效农旅融合区,进行中心城区-中心镇-一般镇-中心村的层级划分和产业方向优化。(3)发展策略应强调分层实施、分类引导,优化城乡利用空间,做好城乡地域分类引导,实现资源要素合理配置。研究成果为认识山地丘陵地区地域功能演化规律、制定城乡一体化发展策略提供了科学案例。  相似文献   
79.
This article explains how to obtain straightforward extensions of the most popular univariate non‐nested statistics, and of the RESET‐test, to a multivariate context and examines how to use these tests to compare alternative factor demand systems. The empirical application involves the classical Berndt–Khaled KLEM data set. A statistically adequate specification is determined for each competing factor demand system. The empirical results are interpreted for each system, the models are compared on the basis of multivariate paired and joint non‐nested procedures and practical indications about what to expect if these tests are applied to alternative factor demand specifications are provided.  相似文献   
80.
More diverse, perennial cropping systems often have better natural mechanisms for keeping pests at bay. But while scientists emphasise the broad benefits of conservation in terms of effective ecosystem functioning, farmers are more interested in biodiversity for the provision of food or of services such as shade or windbreaks. Because of their limited knowledge of the role of biodiversity in plant protection, farmers sometimes unconsciously disturb natural regulatory mechanisms. Some citrus farmers in Vietnam introduced sapodilla as an intercrop to diversify their source of income, and because this fruit tree requires little care. However, this apparently worthwhile attempt to combine two valuable crops has misfired. The ecological conditions that traditionally sustained natural pest control in citrus have been disturbed, thus trapping farmers in the pesticide treadmill. The weaver ant Oecophylla smaragdina stopped protecting citrus from stinkbugs and leaf-feeding caterpillars after facing competition from the black ant Dolichoderus thoracicus, which favours sapodilla trees as a nesting habitat. To avoid similar scenarios in the future, methods for linking scientific research on ecosystem functions with farmers' own knowledge, experience and priorities are presented. Examples are given of ways in which farmers in perennial cropping systems learn, and how scientists can facilitate this learning process.  相似文献   
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