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   19905篇
  免费   1048篇
  国内免费   384篇
财政金融   2012篇
工业经济   971篇
计划管理   4423篇
经济学   4073篇
综合类   2147篇
运输经济   302篇
旅游经济   463篇
贸易经济   2610篇
农业经济   1936篇
经济概况   2400篇
  2024年   57篇
  2023年   455篇
  2022年   457篇
  2021年   677篇
  2020年   857篇
  2019年   633篇
  2018年   562篇
  2017年   775篇
  2016年   741篇
  2015年   692篇
  2014年   1435篇
  2013年   1778篇
  2012年   1614篇
  2011年   1824篇
  2010年   1341篇
  2009年   1251篇
  2008年   1328篇
  2007年   1200篇
  2006年   999篇
  2005年   785篇
  2004年   517篇
  2003年   341篇
  2002年   217篇
  2001年   180篇
  2000年   145篇
  1999年   92篇
  1998年   79篇
  1997年   54篇
  1996年   51篇
  1995年   36篇
  1994年   37篇
  1993年   20篇
  1992年   32篇
  1991年   15篇
  1990年   5篇
  1989年   6篇
  1988年   6篇
  1987年   3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 19 毫秒
91.
Although research into the business model has received increasing attention, few studies have so far been conducted on business model innovation in an international context. The purpose of the study is to identify different patterns of business model innovation which enables international retailers to rebuild their core business logic in new host countries. On the basis of comparing and contrasting the business model changes of 15 international retailers from various home countries to one single host country (China), our study provides an in-depth understanding of business model innovation in the context of international business. By looking at the firms’ capabilities in rebuilding their core logic in the setting of a host country, we reveal six routes of retail business model innovation. Utilizing the lens of organizational learning theory and internationalization, we identify three patterns of resource deployment by international companies in the process of developing business model innovations. Our study, therefore, provides insights and guidance for multinational companies in general, international retailers in particular, as for how to successfully adapt their business model from home country to host country.  相似文献   
92.
In the cointegrated vector autoregression (CVAR) literature, deterministic terms have until now been analyzed on a case-by-case, or as-needed basis. We give a comprehensive unified treatment of deterministic terms in the additive model Xt=γZt+Yt, where Zt belongs to a large class of deterministic regressors and Yt is a zero-mean CVAR. We suggest an extended model that can be estimated by reduced rank regression, and give a condition for when the additive and extended models are asymptotically equivalent, as well as an algorithm for deriving the additive model parameters from the extended model parameters. We derive asymptotic properties of the maximum likelihood estimators and discuss tests for rank and tests on the deterministic terms. In particular, we give conditions under which the estimators are asymptotically (mixed) Gaussian, such that associated tests are χ2-distributed.  相似文献   
93.
Donald Trump’s presidential campaign contains several trade protectionism plans. This paper aims to analyze possible global impact of United States’ plan to impose import tariff increase against China. The GTAP model is implemented. The simulations present possible short-run effects of full-protection and manufacturing-only protection with appropriate retaliation response from China. The policy might lead to GDP, terms-of-trade, and welfare decline in United States and China; and an increase in trade balance for United States. Trade diversion pattern is observed in the simulation results, predicting shrinking bilateral trade between the two countries and increasing export toward their third trading partners.  相似文献   
94.
Mobile communication failure can occur when mobile traffic exceeds the manageable level. This depends on frequency bandwidth. Mobile communication failure causes inconveniences in a user's daily life that lead to social and economic damage. To address this issue, mobile telecommunications companies deploy additional bandwidths and develop new technologies, but these are costly strategies. This study applies a spike model based on a contingent valuation method (CVM) to measure the inconvenience cost resulting from mobile communication failure. The mean monthly willingness-to-pay (WTP) to avoid communication failure per user is estimated to be KRW 898.14 (USD 0.80) over a period of five years in our study. The inconvenience cost borne by the population is estimated to be KRW 2.97 trillion (USD 2.61 billion). Users experiencing greater frequency of communication failure are found to be willing to pay more to avoid the inconvenience. When excluding respondents citing zero-WTP, the mean WTP per user was calculated to be KRW 3426.41 (USD 3.01). Data traffic usage and frequency at which communication failure is experienced are variables that exhibit statistically significant effects on WTP to avoid mobile communication failure. Overall, estimation results show that a price discrimination based on data traffic usage or quality can be considered by mobile telecommunications companies and regulators to address the issue of data traffic inducing mobile communication failure.  相似文献   
95.
Background: Inhibitor development to factor VIII (FVIII) hemophilia therapy results in increased complications and substantial economic costs. The SIPPET study, the first randomized controlled trial to compare the immunogenicity of plasma-derived FVIII (pdFVIII)/von Willebrand factor (VWF) and recombinant-DNA-derived FVIII (rFVIII), demonstrated higher inhibitor rates in previously untreated patients (PUPs) treated with rFVIII than in PUPs treated with pdFVIII/VWF.

Objective: To quantify the economic impact of treating PUPs with pdFVIII/VWF vs rFVIII.

Methods: An Excel-based clinical and economic model was developed from a US healthcare payer perspective and run over a 5-year period. The analysis utilized a cohort approach to model patient treatment and outcomes over a monthly cycle to quantify differences in costs of FVIII, bypassing agents, and hospitalizations for serious bleeds. Rates of high-titer inhibitor development were obtained from the SIPPET study. Patients developing high-titer inhibitors were treated with immune tolerance induction (ITI). Patients who developed low-titer inhibitors and those who did not develop inhibitors continued their usual FVIII treatment. Patients who were successfully treated with ITI returned to FVIII treatment, while unsuccessfully treated patients received bypassing agents. Total costs per treated patient were estimated and a one-way sensitivity analysis was conducted to quantify the impact of parameter uncertainty on the model outcomes.

Results: Total cumulative costs per patient over 5 years were $834,621 for pdFVIII/VWF patients and $1,237,163 for rFVIII patients, representing a total saving of $402,542 per patient over the 5-year period, for an average annual saving of $80,508 per patient.

Conclusions: Based on data from the SIPPET study, this analysis found that initiating FVIII treatment in severe hemophilia A PUPs with pdFVIII/VWF has the potential to offer substantial cost savings to healthcare payers, amounting to a one-third reduction in costs.  相似文献   
96.
提出了一种由单形规范线性分段(SCPWL)函数与记忆多项式级联的数字预失真器,并给出了复数域两步最小二乘参数辨识算法。不同于以往一种预失真器适用一种功放模型的情况,所提的预失真算法利用SCPWL函数的分段特性以及记忆多项式的非线性记忆特性,在完成参数辨识的同时自动地调整结构,可适用于传统以及强非线性新型功放模型的线性化补偿。将所提预失真器分别应用于传统记忆多项式、两箱模型以及新型包络跟踪功放。经过计算机仿真,功放输出的幅频特性和频谱曲线表明所提预失真器能够有效地补偿多种功放的非线性特性。算法仿真比较结果也表明,针对包络跟踪功放,所提复数两步最小二乘算法的邻道泄漏比(ACLR)可改善约35 dB,性能优于最小均方(LMS)类算法约30 dB。  相似文献   
97.
This paper presents a theoretical model based on the Technology Acceptance Model combined with a perceived trust model. SPSS 23 and Amos 22 were used to analyze Chinese tourists’ responses regarding use of biometric technology in hotels and to assess whether their perception of trust – measured through five potential factors – affected their intention to use it. Chinese tourists traveling in Macau were recruited, and three types of biological identification technology were discussed. A total of 600 questionnaires were sent out, and 583 effective questionnaires were recovered. The results that in addition to perceived ease of use, other factors affected visitors’ perceptions of trust. The degrees of effectiveness, however, differed between the three biological identification technologies. Fingerprint technology was revealed to be the most trusted and accepted biometric technology.  相似文献   
98.
Extant scholarship treats national policies concerning labour rights as a function of economic factors and yet neglects influences of policies among economically competing states. Relying on the policy interdependence theory, this study argues that labour rights policy in a state is dependent on its economic competitors’ labour policy decisions. It specifically maintains that the intensifying competition for foreign direct investment and exports as well as against imports channels negative externalities of deteriorating labour protection in competing states which drives expansive downward policy mimicking and leads to a global decline in labour rights – a race to the bottom. Utilising spatial econometric technique to analyse a new data on labour rights for the period 1994–2009, it finds that labour rights practices are interdependent among economic competitors and experience global deteriorations; whereas labour rights laws remain largely independent due to high policy and reputational costs of lowering them and show more fluctuations.  相似文献   
99.
多径效应导致基于信号接收强度(RSSI)的室内定位方法精度不高,采用更细粒度的物理层信道状态信息(CSI)可以区分不同路径,提高定位精度。在已有基于CSI室内定位方法的基础上,通过改进对数距离路径损耗模型,得到CSI与传输距离的关系,并结合目标位置所测得的CSI值回归出目标与发射端的距离,最后通过三边定位法预测出目标的位置坐标。实验表明,相比基于RSSI的定位方法以及已有的基于CSI的定位方法,所提方法2 m以内的误差概率提高了将近40%和20%,有效提高了定位精度。  相似文献   
100.
Understanding how spatial attributes of cities and neighborhoods induce cycling is relevant for urban planning and policy making. In this work, ordered logit and latent class models are specified and estimated to analyze how the built environment affects bicycle-commuting frequency. Data come from a survey to 1,487 people in the city of Santiago, Chile, including sociodemographic information, travel behavior patterns and place of residence and work. Using geographic information systems tools, the built environment was characterized with variables calculated for a 500-m-radius buffer around the residential and work locations of each individual. Two models are estimated, first an ordered logit model confirms that built environment variables effect on cycling is similar to what has been reported in the literature, with some new findings such as an increase in cycling when public transport accessibility is low and the role of built environment attributes at the destination. Second, a latent class ordered logit is used to identify two classes of neighborhood in term of their cycling patterns, as a function of their density, presence of cycling infrastructure and distance to the main activity center of the city. This result allows to map the class membership probabilities, potentially helping to identify neighborhoods that encourage cycling and providing relevant information for policy making and infrastructure decisions.  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