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   2023篇
  免费   126篇
  国内免费   24篇
财政金融   325篇
工业经济   101篇
计划管理   695篇
经济学   330篇
综合类   211篇
运输经济   7篇
旅游经济   14篇
贸易经济   245篇
农业经济   73篇
经济概况   172篇
  2024年   2篇
  2023年   25篇
  2022年   42篇
  2021年   41篇
  2020年   68篇
  2019年   43篇
  2018年   52篇
  2017年   59篇
  2016年   59篇
  2015年   73篇
  2014年   155篇
  2013年   187篇
  2012年   182篇
  2011年   209篇
  2010年   203篇
  2009年   107篇
  2008年   142篇
  2007年   121篇
  2006年   118篇
  2005年   83篇
  2004年   51篇
  2003年   37篇
  2002年   23篇
  2001年   22篇
  2000年   21篇
  1999年   12篇
  1998年   13篇
  1997年   3篇
  1996年   7篇
  1995年   1篇
  1994年   3篇
  1993年   2篇
  1991年   1篇
  1990年   1篇
  1989年   3篇
  1984年   1篇
  1982年   1篇
排序方式: 共有2173条查询结果,搜索用时 15 毫秒
31.
We demonstrate how it is possible to generate value for an investor with a hedge attached to the buy-and-hold strategy of an S&P 500 index fund. We study the S&P 500 index portfolio (not including dividends) and the value-weighted S&P 500 index portfolio (including dividends) of the Center for Research in Securities Prices for 1967:01–2011:12, using the capacity utilization and the unemployment rates in real time to determine if a hedge position should be initiated or closed. A hedge is initiated if the capacity utilization, the unemployment rate or a combination of the two signals a contraction in the real economy. The hedge position is closed if it signals otherwise an expansion. We use utility gains (Campbell and Thompson 2008), the manipulation-proof performance measure (MPPM) statistics (Ingersoll et al. 2007) and the P-Sharpe ratio (Bailey and López de Prado 2012) to evaluate the performance of a particular hedge strategy. The empirical results show that there are infinitely many hedges that can generate positive utility gains, higher MPPM statistics and higher P-Sharpe ratios.  相似文献   
32.
Most small-scale social economies are characterised by their deficiency, lack, and/or difficulty in matching natural data. Against this backdrop, this paper builds a relatively uniform theoretical framework and designs a more economical and objective method for demarcating ecological conservation redlines (ECR) based on sensitivity assessment of ecosystem services. The results show that the sensitivity assessment model designed in this study can identify sensitive zones effectively, and that the ECR in Hubei Province are well within the sensitive zones so identified. The delimited areas based on the sensitive assessment of ecosystem services have great similarities (95%) with the actual ECR areas in Hubei Province. The most ecologically important functional zones (EIFZ) can also be identified using the regional ecological sensitivity coefficient. When the threshold of EIFZ is set higher, the probability that it falls within the ecologically sensitive areas is greater and the ECR delimited by the method proposed in this study will be more reliable. Theoretically, the delimitation of ECR can be inserted at any evaluation level with a grid resolution higher than that of the land use data, which can be used as a supplement to the ECR delimitation method in ecology or geography.  相似文献   
33.
Among Asian economies, Hong Kong has experienced the highest real growth in house prices since the 2010s. Two macroprudential measures, namely credit tightening (loan-to-value ratio cap) and transaction taxes (stamp duty), were introduced to cool down the overheated housing market. This study examines and compares their effectiveness based on a set of constant-quality house price indices. Through an error correction model, we find that credit tightening was able to curb house price growth in the high-price segment, while transaction taxes could not. An explanation is that the exemptions from transaction taxes for those with genuine housing needs could be abused by other market participants. It is easier for buyers to exploit the exemptions to get around the stamp duty than to manipulate the property valuation for mortgage lending. The implication is that the effectiveness of macroprudential measures hinges on whether compliance or exemption can be easily monitored and enforced.  相似文献   
34.
Using daily data from August 9, 2015, to July 7, 2020, this study examines the effects of economic policy uncertainty (EPU) on the returns of four cryptocurrencies: Bitcoin, Ethereum, Litecoin, and Ripple. To this end, two new measures of EPU (Twitter-based economic uncertainty and Twitter-based market uncertainty) are considered. A Granger causality test using the recursive evolving window approach shows a significant causality between the Twitter-based EPU measures and the BTC/USD exchange rate from October 2016 to July 2017. Moreover, a significant causality was noted from the EPU measures to the ETH/USD exchange rate from June 2019 to February 2020 and from the EPU measures to the XRP/USD exchange rate from January 2020 to February 2020. The Twitter-based EPU measures primarily positively affect the returns of the related cryptocurrencies during these periods. These results are robust to different measures of Twitter-based EPU and different econometric techniques. Potential implications, including the COVID-19 era, are also discussed.  相似文献   
35.
李勇 《价值工程》2015,(17):107-109
本文以某电厂1000MW机组塔式锅炉水冷壁垂直段组合、安装为例,介绍塔式锅炉水冷壁垂直段组合、安装方案的确定过程,以其成功安装经验,对于同类型锅炉水冷壁安装具有一定借鉴意义。  相似文献   
36.
陈震 《价值工程》2014,(27):107-108
通过对大湖下行联络线岩溶地质钻孔桩施工出现问题的论述,结合岩溶地质钻孔桩常用的处理方法,提出了适应本区域岩溶地质环境的二次成孔护壁法在钻孔桩施工中的应用,并得到了成功的验证。  相似文献   
37.
王联平 《价值工程》2014,(28):138-140
本文通过双轮铣在深圳地铁福邻站地下连续墙施工中的应用,阐述了其设备的施工原理、施工工艺、施工工效以及其主要的技术要点,并在此基础上初步探讨了液压双轮铣在深圳地铁施工的可行性和延续性。  相似文献   
38.
马伟 《价值工程》2014,(15):129-130
文章分析了加气块填充墙裂缝的开裂成因,并提出了相应的预防措施。  相似文献   
39.
This paper examines whether corporate payout choices (dividends or share repurchases) are associated with intercorporate ownership in a firm. Using the System for Electronic Document Analysis and Retrieval (SEDAR) and the Inter‐Corporate Ownership (ICO) database from Statistics Canada, I find that intercorporate ownership is positively associated with a firm’s propensity to pay dividends and negatively associated with a firm’s propensity to repurchase shares. The findings are robust to the endogeneity of intercorporate ownership and the inclusion of various control variables such as firm size, risk, liquidity, growth, and profitability.  相似文献   
40.
In this paper, we examine the stock market integration process amongst 17 Economic and Monetary Union (EMU) countries from January 2002 to June 2013 over a normal period as well as for the Global Financial Crisis (GFC) and Eurozone Debt Crisis (EDC) periods. We classify the economies in three groups (A, B and C) based on their GDP to examine whether the economic size influences financial integration. Seven indicators are used for the purpose, namely, beta convergence, sigma convergence, variance ratio, asymmetric DCC, dynamic cointegration, market synchronisation measure and common components approach. The results suggest that large-sized EMU economies (termed as Group A) exhibit strong stock market integration. Moderate integration is observed for middle-sized EMU economies with old membership (termed as Group B). Small-sized economies (termed as Group C) economies seemed to be least integrated within the EMU stock market system. The findings further suggest presence of contagion effects as one moves from normal to crisis periods, which are specifically stronger for more integrated economies of Group A. We recommend institutional, regulatory and other policy reforms for Group B and especially Group C to achieve higher level of integration.  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