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   15880篇
  免费   1561篇
  国内免费   87篇
财政金融   2229篇
工业经济   971篇
计划管理   3306篇
经济学   3021篇
综合类   1482篇
运输经济   253篇
旅游经济   203篇
贸易经济   2624篇
农业经济   874篇
经济概况   2552篇
信息产业经济   2篇
邮电经济   11篇
  2024年   10篇
  2023年   84篇
  2022年   189篇
  2021年   423篇
  2020年   464篇
  2019年   670篇
  2018年   413篇
  2017年   671篇
  2016年   562篇
  2015年   705篇
  2014年   838篇
  2013年   1348篇
  2012年   1285篇
  2011年   1511篇
  2010年   1391篇
  2009年   1014篇
  2008年   1098篇
  2007年   1006篇
  2006年   1077篇
  2005年   965篇
  2004年   363篇
  2003年   367篇
  2002年   337篇
  2001年   316篇
  2000年   177篇
  1999年   66篇
  1998年   29篇
  1997年   21篇
  1996年   14篇
  1995年   17篇
  1994年   15篇
  1993年   22篇
  1992年   7篇
  1991年   7篇
  1989年   2篇
  1988年   8篇
  1987年   5篇
  1986年   1篇
  1985年   5篇
  1984年   7篇
  1983年   3篇
  1981年   3篇
  1979年   2篇
  1978年   1篇
  1976年   1篇
  1974年   1篇
  1973年   1篇
  1971年   2篇
  1970年   1篇
  1969年   2篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
企业员工配置是企业内部管理的重要一环,经济政策不确定性是否会影响企业员工配置?本文以员工数量衡量企业员工配置,利用2010-2018年沪深A股上市企业数据和经济政策不确定性指数建立面板数据模型,考察经济政策不确定性对企业员工配置的影响,实证研究发现:经济政策不确定性会显著增加企业员工配置,且该影响经更换变量、调整样本容量以及内生性处理后依旧显著,该反应在还债能力较弱、盈利能力较差、股权制衡度较高、地区经济发展水平较低的企业中更为明显。文章的研究结论对于企业管理和宏观经济管控有一定的参考价值。  相似文献   
22.
Drawing on 45 semi‐structured interviews with union negotiators active in the Quebec private sector, this article shows that local bargaining practices, despite their plurality, have tended to change following major trends. It also reveals, more fundamentally, a redefinition of the ‘rules of the game’. The transformation and stability of these social rules, which are much more focused on the needs of employers, have tended to weaken collective bargaining as a tool for industrial democracy.  相似文献   
23.
This study examines why most derivatives markets that settle on the day following expiration choose the opening rather than the closing price as the final settlement price (FSP), whereas most markets that settle on the expiration day select an average rather than a single price as the FSP. Four exogenous changes in the Taiwan Futures Exchange settlement procedures provide an experimental basis for studying the settlement procedures’ impact on underlying assets. Greatest market efficiency is observed when the FSP is determined by a single rather than an average price and hypothesize that manipulation is prevented at the expense of market quality.  相似文献   
24.
In this study, an epsilon-based network data envelopment analysis is employed to construct assessment mechanisms for government performance. Moreover, performance indicators of two dimensions of tax collection efficiency and financial effectiveness are measured. We propose a vector autoregression model in which all economic variables are regarded as dependent variables to address the disadvantages of traditional regression model. The conclusions are as follows: (a) measures of tax collection efficiency deteriorated, whereas those of financial effectiveness improved. (b) In an impulse response analysis of the model, an increase in government-published land values produced significantly increased tax collection efficiency.  相似文献   
25.
This paper examines the role of media coverage and investor attention on the outcomes of seasoned equity offerings (SEOs). I use an archive of Thomson Reuters news articles to proxy for firm visibility and investor attention. I find that the volumes of news articles prior to the offerings are positively associated with the offer price discounts of SEOs. Furthermore, the volumes of news articles are negatively associated with the cumulative abnormal returns three days around the SEOs. I conclude that the costs of equity increase with media coverage prior to SEOs. Overall, the evidence is consistent with the hypothesis that media coverage affects investors' information processing in SEOs. Copyright © 2018 ASAC. Published by John Wiley & Sons, Ltd.  相似文献   
26.
This study analyzes the macroeconomic impacts of subsidies to attract multinational corporations when firms are determining whether to enter or how to serve foreign markets. We show that a small FDI subsidy scheme induces consumption gains and delivers short‐term welfare improvement for the FDI host country if firms differ in productivity. However, the subsidy generates a new problem and results in the wealth reallocation effect, leading to welfare deterioration for the host country in the long run. Moreover, we find that a subsidy program induces a welfare improvement for the host country if it is offered to all domestic producers instead of foreign producers only in the host country.  相似文献   
27.
We study the optimal execution problem with multiplicative price impact in algorithmic trading, when an agent holds an initial position of shares of a financial asset. The interselling decision times are modeled by the arrival times of a Poisson process. The criterion to be optimized consists in maximizing the expected net present value of the gains of the agent, and it is proved that an optimal strategy has a barrier form, depending only on the number of shares left and the level of the asset price.  相似文献   
28.
基于冠层光谱和BP神经网络的水稻叶片氮素浓度估算模型   总被引:4,自引:0,他引:4  
[目的]快速、准确地诊断水稻叶片氮素营养状况,为水稻氮肥精准管理提供依据。[方法]以江西省农科院8种不同施肥处理的晚稻为研究对象,于主要生育期同步测定了水稻冠层光谱反射率及叶片全氮浓度(Leaf Nitrogen Concentration,LNC),系统分析了原始光谱反射率、一阶微分光谱、"三边"参数以及由350~1 350nm两两波段组合的差值(SD (Rλ1,Rλ2))、比值(SR (Rλ1,Rλ2))及归一化(ND(Rλ1,Rλ2))光谱指数与水稻LNC的相关关系,筛选出敏感参数,并以之为自变量构建了水稻LNC的传统预测模型,另外构建不同指标个数的多元线性与BP神经网络模型,并对模型进行验证。[结果](1)水稻LNC与一阶微分光谱在751nm处的相关性最高(r=0. 822);(2)"三边"参数中的红边面积SDr与LNC的相关性较高(r=0. 687);(3) 750nm附近的红边波段与近红外波段差值组合、550nm附近的绿光波段与近红外波段的比值及归一化差值组合与水稻LNC的相关性较高,以SD (R752,R751)、SR (R534,R1 350)和ND (R534,R1 349)表现最好,相关系数分别为0. 827、-0. 790和0. 788;(4)传统回归模型中以SD(R752,R751)构建的一元线性模型最佳(RC2=0. 665、RV2=0. 750、RMSEV=0. 4%、RPD=2. 034);(5)利用5个指标((R'751、SDr、SD (R752,R751)、SR (R534,R1 350)、ND (R534,R1 349))经逐步回归筛选出的2个指标SD ((R752,R751)和SR (R534,R1 350))构建预测水稻氮素的BP神经网络模型,预测效果最佳,其验证参数值分别为R2=0. 859、RMSEV=0. 302%和RPD=2. 669。[结论]基于单指标构建的传统线性模型计算过程简单但精度略低,而基于2个指标(SD (R752,R751)、SR (R534,R1 350))构建的BP神经网络模型预测精度高于该2指标构建的多元线性模型,表明在指标适合的情况下,BP神经网络对氮素具有较好的预测能力,是一种快速准确估算水稻叶片全氮浓度的方法。  相似文献   
29.
Disclosure standards mandate the quantitative disclosure of hedging‐instrument‐related risks but not the disclosure of hedged‐item‐related risks. We examine how a match (mismatch) in formats, caused by making quantitative (qualitative) hedged item disclosures alongside quantitative hedging instrument disclosures, affects investors' integration of information from these two related disclosures. Our first experiment varies the hedged item disclosure format (quantitative or qualitative) and the portion of risk hedged (small or large). We find that when disclosure formats are mismatched, the less comparable nature of the two disclosures caused investors to neglect the offsetting relationship when assessing net risks. As a result, risk and investment judgments were influenced by the more prominent quantitative hedging instrument disclosures. Our second experiment finds that the use of a qualitative debiaser that clarifies the relationship between the two disclosures led to the integration of information and mitigated this effect.  相似文献   
30.
张震  郑檩  张雷  靳晔 《科技和产业》2021,21(2):243-248
为研究自动涂胶系统的胶枪最优材质、最佳热源位置和最佳测温位置,利用ANSYS Workbench软件对自粘胶胶枪进行数值模拟.通过分析不同材质胶枪的温度场分布情况,结合经济性和加热性能,选定最优胶枪基材.同时分析得出加热自粘胶至工作温度的时间和保持工作温度的加热功率,确定了热源和测温点位置,拟定了升温策略.进行自粘胶胶枪加热试验,验证了仿真分析结果的准确性.  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