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   20752篇
  免费   785篇
  国内免费   384篇
财政金融   2069篇
工业经济   1002篇
计划管理   4484篇
经济学   4197篇
综合类   2177篇
运输经济   316篇
旅游经济   484篇
贸易经济   2702篇
农业经济   2003篇
经济概况   2487篇
  2024年   133篇
  2023年   465篇
  2022年   471篇
  2021年   688篇
  2020年   882篇
  2019年   644篇
  2018年   572篇
  2017年   795篇
  2016年   763篇
  2015年   702篇
  2014年   1464篇
  2013年   1809篇
  2012年   1641篇
  2011年   1867篇
  2010年   1365篇
  2009年   1287篇
  2008年   1369篇
  2007年   1238篇
  2006年   1033篇
  2005年   808篇
  2004年   527篇
  2003年   347篇
  2002年   223篇
  2001年   179篇
  2000年   147篇
  1999年   99篇
  1998年   81篇
  1997年   54篇
  1996年   54篇
  1995年   37篇
  1994年   38篇
  1993年   21篇
  1992年   34篇
  1991年   22篇
  1990年   6篇
  1989年   6篇
  1988年   6篇
  1987年   4篇
  1986年   9篇
  1985年   14篇
  1984年   11篇
  1983年   2篇
  1982年   2篇
  1981年   2篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
191.
In this paper empirical evidence is presented on theelasticity of private R & D spending on its price. Acensored panel-data regression model with random effectsis applied to a balanced panel of 726 Italian firms overthe 1992–1997 period. Implied estimates point out thatItalian firms' response to policy measures (including taxcredits), aimed at reducing the user cost of R & D capital,is likely to be substantial (1.50–1.77). Furthermore, wealso find that the elasticity of R & D spending is higherin recession (2.01) than in expansion (0.87).  相似文献   
192.
中英电信"双寡头垄断"模式比较研究   总被引:9,自引:0,他引:9  
中国电信南北分拆以后,将在固定电话和移动电话两个业务领域形成新一轮"双寡头垄断"竞争格局.英国是率先实行"双寡头垄断"作为过度,最终走向电信全面开放竞争的典范.中国电信业在1994~1999年第一阶段改革中,曾试图仿效"英国模式",构建中国电信和中国联通的"双寡头垄断",最终以失败告终.在中国即将形成新一轮"双寡头垄断"竞争格局之时,我们有必要通过对英国电信改革的理论背景、具体实施过程、取得的成就的回顾,探求英国"双寡头垄断"成功的奥秘,并为中国新一轮电信重组所借鉴,提升中国的电信业国际竞争力,更好地应对WTO的挑战.  相似文献   
193.
文章探讨了影响农村劳动力非农就业倾向的主要因素。研究结果表明,区位条件对农村劳动力非农就业倾向的影响,主要表现为近城地区以大量企业及相对发达的各种要素市场为第一优势,吸纳了更多劳动力进入本地企业就业。教育总体上是影响农村劳动力非农就业倾向的最重要因素。但其在近城地区的影响却位居第二。在远城地区教育对增大农村非农就业倾向的作用更为显著,而且受教育程度越高这种倾向就越显著。各种文化水平的影响都普遍促进了劳动者到外地企业就业,但对进入本地企业就业和家庭非农经营的促进却并不普遍,其中初中教育对农民在本地企业就业的作用更显著些;高中教育提高农民从事非农家庭经营的倾向最为明显。耕地数量抑制农户劳动力外出务工,但对其在本地企业就业和家庭非农经营的影响也不显著。乡镇企业的发展增大了农民进入本地企业的就业倾向,劳动者供养的非劳动人口数量对农民非农就业的正向影响不显著,农户拥有的非农业和农业生产性资产对农村非农就业的影响不大。因此,加快推进农村城镇化;加强边远农村地区的中等教育,特别是职业技能教育;大力发展乡企和私企;完善农村社会保障体系;构建农村劳动供求信息系统等,是促进农村劳动力加速向非农产业转移的重要途径。  相似文献   
194.
物流发展IGJAHP评价模型及空间格局分析--以安徽省为例   总被引:8,自引:0,他引:8  
采用模糊区间层次分析法(IGJAHP),构筑物流产业发展综合评价模型,对安徽省物流发展的总体水平进行测算,并将其进程划分为恢复建设、缓慢发展、快速发展以及现代物流发展等四个阶段;在综合分析的基础上,把安徽省物流划分为皖江物流发展轴,合肥、蚌埠、阜阳物流大三角,东部外围和中西部等四大空间格局;而后,对安徽省17个地市历年物流发展水平进行评估,并计算物流发展地域差异系数,结果显示安徽省物流发展在空间上呈现地域差异扩大的趋势,在时间上经历了分散阶段和集中化阶段两个过程;然后,对安徽省物流生成量进行科学测算,分析显示其空间分布比较均匀。最后,从综合物流网络、物流信息通道、物流企业再造以及物流法规等方面提出发展对策。  相似文献   
195.
Objective: To investigate preferences for fertility treatment from the Australian general population with the aims of calculating the willingness to pay in tax contribution for attributes (characteristics) that make up treatment and for an “ideal” fertility treatment program. We also assessed whether willingness-to-pay varies by the relationship status or sexual orientation of the patient.

Methods: A stated preference discrete choice experiment was administered to a panel of 801 individuals representative of the Australian general population. Seven attributes of fertility treatment under three broad categories were included: outcome, process, and cost. Attributes were identified through published literature, focus group discussions, expert knowledge, and a pilot study. A Bayesian fractional experimental design was used, and data analysis was performed using a generalized multinomial logit model. Further analyses included interaction terms and latent class modeling.

Results: Six of the seven attributes influenced the choice of a treatment program. Under process attributes, individuals preferred: continuity of care of clinic staff, where patients are seen by the same doctor but different nurses at each visit; “alternative” treatments being offered to all patients; and onsite clinic counseling and peer-support groups. Personalization and tailoring of the treatment journey were not important. Among outcome attributes, the improved success rate of having a baby per cycle and significant side-effects were considered important. Cost of treatment also influenced the choice of treatment program. Individual preferences for fertility treatment were not associated with patients’ relationship status or sexual orientation. Latent class modeling revealed sub-groups with distinct fertility treatment preferences.

Conclusion: This study provides important insights into the attributes that influence the preferences of fertility treatment in Australia. It also estimates socially-inclusive willingness-to-pay values in tax contributions for an “ideal” package of treatment. The results can inform economic evaluations of fertility treatment programs.  相似文献   

196.
The Bank of England first acquired a macroeconomic model of the UK economy in early 1973, and used it for forecasting in June and July of that year. The initial model was obtained from the London Business School (LBS), but the last 14 years or so have, on the part of both the Bank and the LBS, led to developments which now make the models no closer to each other than to other large scale models of the UK. This article describes the structure and central properties of the current version of the Bank model, which has some 663 variables, 134 of which are modelled by behavioural equations, 153 by technical equations, 212 identities and 164 exogenous variables. In order to provide a transitional step between the kind of models with which most macroeconomists are familiar and the full scale version of the Bank model, one part of the article presents a very simple stylized version of the full model. This is a stepping stone to the full model which is described and analysed on a sectoral basis in Part 3, with a complete listing of equations in Part 4. Some of the simulation properties, and hence full model dynamic responses, are considered in Part 5.  相似文献   
197.
本文从农业可持续发展、资源永续利用的原则出发,探讨了构建生态农业模式的原则,以山东省广饶县为例,系统分析了在该县构建和应用生态农业模式的优势条件和制约因素,具体论述了适合广饶县发展的三种生态农业模式:农—牧—沼型、上粮下渔型和草—畜—乳型生态农业模式。  相似文献   
198.
Use of biofuels diminishes fossil fuelcombustion thereby also reducing net greenhousegas emissions. However, subsidies are neededto make agricultural biofuel productioneconomically feasible. To explore the economicpotential of biofuels in a greenhouse gasmitigation market, we incorporate data onproduction and biofuel processing for thedesignated energy crops switchgrass, hybridpoplar, and willow in an U.S. AgriculturalSector Model along with data on traditionalcrop-livestock production and processing, andafforestation of cropland. Net emissioncoefficients on all included agriculturalpractices are estimated through crop growthsimulation models or taken from the literature. Potential emission mitigation policies ormarkets are simulated via hypothetical carbonprices. At each carbon price level, theAgricultural Sector Model computes the newmarket equilibrium, revealing agriculturalcommodity prices, regionally specificproduction, input use, and welfare levels,environmental impacts, and adoption ofalternative management practices such asbiofuel production. Results indicate no rolefor biofuels below carbon prices of $40 perton of carbon equivalent. At these incentivelevels, emission reductions via reduced soiltillage and afforestation are more costefficient. For carbon prices above $70,biofuels dominate all other agriculturalmitigation strategies.  相似文献   
199.
斯蔼  汤洁  王娟  李海毅 《经济地理》2005,25(6):757-760
针对吉林省大安市发展现状和存在的严重生态环境问题,运用生态足迹模型,采用多源数据,首次对大安市生态环境的可持续发展状况进行了定量研究;在此基础上,运用相对指标法对可持续发展的量化结果进行分级。研究表明,2001年大安市的生态需求大于生态供给,生态呈现“供不应求”的局面,人均生态赤字为0.56hm2,处于弱不可持续发展状态。  相似文献   
200.
研究了不确定语言型多属性决策评价结果与决策者对方案的偏好信息之间存在偏差的问题,提出了基于投影模型的不确定多属性决策方法。该方法通过建立与区间型语言标度对应的术语指标矩阵,及方案综合属性值与决策者主观偏好值之间的投影模型,确定属性的权重,然后运用加权法得到方案的综合属性值,利用已有的可能度矩阵排序公式得到决策方案的排序。最后,通过算例对该方法的实用性和有效性进行了说明。  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