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排序方式: 共有1412条查询结果,搜索用时 15 毫秒
1.
We introduce a new type of heavy‐tailed distribution, the normal reciprocal inverse Gaussian distribution (NRIG), to the GARCH and Glosten‐Jagannathan‐Runkle (1993) GARCH models, and compare its empirical performance with two other popular types of heavy‐tailed distribution, the Student's t distribution and the normal inverse Gaussian distribution (NIG), using a variety of asset return series. Our results illustrate that there is no overwhelmingly dominant distribution in fitting the data under the GARCH framework, although the NRIG distribution performs slightly better than the other two types of distribution. For market indexes series, it is important to introduce both GJR‐terms and the NRIG distribution to improve the models’ performance, but it is ambiguous for individual stock prices series. Our results also show the GJR‐GARCH NRIG model has practical advantages in quantitative risk management. Finally, the convergence of numerical solutions in maximum‐likelihood estimation of GARCH and GJR‐GARCH models with the three types of heavy‐tailed distribution is investigated.  相似文献   
2.
Aims: The EINSTEIN-Extension trial (EINSTEIN-EXT) found that continued treatment with rivaroxaban for an additional 6 or 12 months (vs placebo) after 6–12 months of initial anticoagulation significantly reduced the risk of recurrent venous thromboembolism (VTE) with a small non-significant increased risk of major bleeding (none fatal or in critical site). This study aimed to compare total healthcare cost between rivaroxaban and placebo, based on the EINSTEIN-EXT event rates.

Methods: Total healthcare cost was calculated as the sum of treatment and clinical event costs from a US managed care perspective. Treatment duration and event rates were obtained from the EINSTEIN-EXT study. Adjustment on treatment duration was made by assuming a 10% non-adherence rate. Drug costs were based on wholesale acquisition costs. Cost estimates for clinical events (i.e. recurrent deep vein thrombosis [DVT], recurrent pulmonary embolism, major bleeding, clinically relevant non-major bleeding) were determined from the literature. Results were examined over a ±20% range of each cost component and over 95% confidence intervals (CIs) of event rate differences in deterministic (one-way) and probabilistic sensitivity analyses (PSA).

Results: Total healthcare cost was $1,454 lower for rivaroxaban-treated (vs placebo-treated) patients in the base-case, with a lower clinical event cost fully offsetting drug cost. The cost savings of recurrent DVT alone (–$3,102) was greater than drug cost ($2,723). Total healthcare cost remained lower for rivaroxaban in the majority (73%) of PSA (cost difference [95% CI]?=?–$1,454 [–$2,396, $1,231]).

Limitations: This study was conducted over the 1-year observation period of the EINSTEIN-EXT trial, which limited “real-world” applicability and examination of long-term economic impact. Assumptions on drug and clinical event costs were US-based and, thus, not applicable to other healthcare systems.

Conclusions: Total healthcare costs were estimated to be lower for patients continuing rivaroxaban therapy compared to those receiving placebo in VTE patients who had completed 6–12 months of VTE treatment.  相似文献   
3.
Objective: To review, summarize, and analyze both similarities and differences of pharmacoeconomic (PE) guidelines, to enable researchers to access their characteristics and the current state of PE guidelines; furthermore, to learn which methodological issues still remain contested and to promote the methodological development of PE guidelines.

Materials and methods: The authors performed a search for PE guidelines using PubMed, the Cochrane library database, and the websites of the International Society for Pharmacoeconomics and Outcomes Research. Information of each guideline was extracted using a pre-designed extraction template, which included 22 aspects; the guidelines were summarized in the forms of charts, and their characteristics have been described.

Results: A total of 40 PE guidelines were studied. The most common methodological issues include the types of analysis, sources for effectiveness, use of quality-adjusted life-years (QALYs) to measure outcomes, and use of incremental cost effectiveness ratios to present results. The majority of the guidelines preferred a cost utility analysis with outcomes expressed in terms of QALYs. Most of the guidelines preferred meta-analysis or meta-analysis of the randomized controlled trials, and required a systematic review of all evidence. Issues that varied most in the guidelines were the choice of the comparator, recommended costs to be included, methods related to indirect cost calculations, methods of sensitivity analysis, and discounting rate.

Conclusion: A comparison of these guidelines revealed that a number of differences exist among them in several key aspects, and some critical methodological issues still exist, for which no best solution is available. Furthermore, efforts need to be made to develop harmonious methods for the PE, and to improve the transferability of the outcomes of PE evaluations.  相似文献   
4.
We compare real-time density forecasts for the euro area using three DSGE models. The benchmark is the Smets and Wouters model, and its forecasts of real GDP growth and inflation are compared with those from two extensions. The first adds financial frictions and expands the observables to include a measure of the external finance premium. The second allows for the extensive labor-market margin and adds the unemployment rate to the observables. The main question that we address is whether these extensions improve the density forecasts of real GDP and inflation and their joint forecasts up to an eight-quarter horizon. We find that adding financial frictions leads to a deterioration in the forecasts, with the exception of longer-term inflation forecasts and the period around the Great Recession. The labor market extension improves the medium- to longer-term real GDP growth and shorter- to medium-term inflation forecasts weakly compared with the benchmark model.  相似文献   
5.
This paper examines the out-of-sample forecasting properties of six different economic uncertainty variables for the growth of the real M2 and real M4 Divisia money series for the U.S. using monthly data. The core contention is that information on economic uncertainty improves the forecasting accuracy. We estimate vector autoregressive models using the iterated rolling-window forecasting scheme, in combination with modern regularisation techniques from the field of machine learning. Applying the Hansen-Lunde-Nason model confidence set approach under two different loss functions reveals strong evidence that uncertainty variables that are related to financial markets, the state of the macroeconomy or economic policy provide additional informational content when forecasting monetary dynamics. The use of regularisation techniques improves the forecast accuracy substantially.  相似文献   
6.
为探索更优的数字化交付技术架构及实施路线,提高数字化交付在煤化工项目中的应用水准,以某公司数字化交付项目为研究对象,详细梳理了三维建模、管道仪表流程图绘制、结构化文档及非结构化数据收集等方面在航天炉气化岛数字化交付项目中的实施情况,对实施方案及重点内容进行讨论,对比分析了各平台之间的优劣。结合数字化交付领域的现状,对当前煤化工产业数字化交付项目中存在的问题进行了探讨,从政策、业主、工程公司及软件平台商等方面给出了解决方法和优化建议。结果表明:1)采用PDMS,SP P&ID及其他专业技术软件支持下的AVEVA NET数字化交付平台体系架构合理,并且能够顺利完成交付实施;2)合理的实施步骤、更高的重视程度、明确的政策规范以及有效的信息传递方式可以明显改善数字化交付项目的优化效果,目前应着重提升工程公司的三维建模能力及软件商的技术水平。探讨结果不仅可以为其他企业的数字化交付工作提供借鉴,还可为实现智能工厂提供了建设思路和数据支持。  相似文献   
7.
We believe that what most authors have in mind when referring to the “most redistributive country” is a tax and transfer schedule that is most redistributive across all pre-tax and transfer income distributions. In order to measure each country's tax and transfer redistribution according to the same baseline, we suggest using the transplant-and-compare method of Dardanoni and Lambert (2002, Journal of Public Economics 86, 99–122) to establish a common base. The redistributive effects of countries’ tax and transfer schedules are illustrated by employing microdata on eight countries from the Luxembourg Income Study (LIS). Of these eight countries, Finland is found to be the most redistributive country, according to the common base method.  相似文献   
8.
目的:比较传统玻璃蒸馏瓶蒸馏装置、二氧化硫测定仪、自动凯氏定氮仪3种仪器测定食品中二氧化硫的效果及适用性,为设备选型提供参考.方法:选取番薯干、咸菜、香菇干,分别用上述3种蒸馏装置测定样品中的二氧化硫含量,分析测定结果和过程控制.结果:使用3种不同蒸馏仪器测定结果无显著性差异,两次独立测定结果的绝对差值小于算术平均值的10%,回收率均在85%~95%.结论:二氧化硫测定仪自动化程度高,安全性高,基本可以替代传统玻璃蒸馏瓶蒸馏,实现大部分食品的批量检测,对于香菇干等蒸馏过程易倒吸食品,可采用自动凯氏定氮仪检测,提高实验的准确性和可靠性.  相似文献   
9.
Large-scale land deals have attracted considerable attention for various reasons, including their implications for local livelihoods. While some view the phenomena as a development opportunity, encompassing improvement in the livelihoods of local people, others argue that it is an impoverishing scheme. Ethiopia ranks among the top in terms of the size of land leased out over the last decade. Land is a major resource of state control and investment in Ethiopia. As the foundation of their livelihoods and identity, it is simultaneously a vital resource for the local people. Highlighting the importance of land for local livelihoods and state-society relations and employing a political-ecological approach, this paper analyzes the outcomes of two land lease cases for the local people in Bakko Tibbe district of Oromia, Ethiopia. The findings show that the land leases induced a significant decline in local people’s access to land, resulting in a significant reduction in crop production and livestock husbandry. The land leases also dismantled longstanding land-based social relations in both production systems. Based on empirical evidence from specific localities and contextualizing the local livelihood dynamics within broader political-economic conditions, this study contributes to the ongoing debate on livelihood impacts of global land deals.  相似文献   
10.
This study investigated whether variations in personality traits are related to board game usage patterns and attitudes, and whether such associations are expressed differently across countries that reflect different cultural orientations and values. A cross-sectional online survey was distributed among 486 Danes, Germans, and Americans, whose personalities were assessed through the NEO-FFI questionnaire. Participants also indicated their liking levels, attitudes, and playing frequency of board games. Results showed significant associations between personality traits and board game-related attitudes and habits. However, these associations were moderated by culture and primarily predicted responses among Danish participants, but not their American or German counterparts. These findings have important implications for the board-game industry, a multi-billion-dollar market worldwide. Furthermore, findings can shed light on how to better personalize and design board games according to personality traits and culture-specific preferences, which should have a significant impact on the user experience and ultimately increase sales.  相似文献   
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