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   2485篇
  免费   73篇
  国内免费   7篇
财政金融   354篇
工业经济   179篇
计划管理   412篇
经济学   491篇
综合类   152篇
运输经济   49篇
旅游经济   63篇
贸易经济   402篇
农业经济   116篇
经济概况   342篇
邮电经济   5篇
  2024年   2篇
  2023年   16篇
  2022年   40篇
  2021年   73篇
  2020年   71篇
  2019年   64篇
  2018年   55篇
  2017年   78篇
  2016年   82篇
  2015年   73篇
  2014年   89篇
  2013年   302篇
  2012年   206篇
  2011年   204篇
  2010年   176篇
  2009年   145篇
  2008年   152篇
  2007年   143篇
  2006年   139篇
  2005年   104篇
  2004年   44篇
  2003年   36篇
  2002年   55篇
  2001年   36篇
  2000年   24篇
  1999年   16篇
  1998年   23篇
  1997年   6篇
  1996年   13篇
  1995年   6篇
  1994年   10篇
  1993年   11篇
  1992年   5篇
  1991年   7篇
  1990年   7篇
  1989年   6篇
  1988年   8篇
  1987年   5篇
  1986年   6篇
  1985年   7篇
  1984年   6篇
  1983年   4篇
  1982年   1篇
  1980年   3篇
  1977年   3篇
  1973年   1篇
  1972年   1篇
  1969年   1篇
排序方式: 共有2565条查询结果,搜索用时 0 毫秒
71.
Aims: Adverse events (AEs) associated with treatments for metastatic colorectal cancer (mCRC) may compromise the course of treatment, impact quality-of-life, and increase healthcare resource utilization. This study assessed the direct healthcare costs of common AEs among mCRC patients in the US.

Methods: Adult mCRC patients treated with chemotherapy or targeted therapies were identified from administrative claims databases (2009–2014). Up to the first three mCRC treatment episodes per patient were considered and categorized as with or without the AE system/organ category during the episode. Total healthcare costs (2014 USD) were measured by treatment episode and reported on a monthly basis. Treatment episodes with the AE category were matched by treatment type and line of treatment to those without the AE category. Adjusted total cost differences were estimated by comparing costs during treatment episodes with vs without the AE category using multivariate regression models; p-values were estimated with bootstrap.

Results: A total of 4158 patients with ≥1 mCRC treatment episode were included (mean age?=?59 years; 58% male; 60% with liver and 14% with lung metastases; 2,261 [54%] with a second and 1,115 [27%] with a third episode). On average, two treatment episodes were observed per patient with an average length of 166 days per episode. Adjusted monthly total cost difference by AE category included hematologic ($1,480), respiratory ($1,253), endocrine/metabolic ($1,213), central nervous system (CNS; $1,136), and cardiovascular ($1,036; all p?Limitations: Claims do not include information on the cause of AEs, and potentially less severe AEs may not have been reported by the physician when billing the medical service. This study aimed to assess the association between costs and AEs and not the causation of AEs by treatment.

Conclusions: The most costly AEs among mCRC patients were hematologic, followed by respiratory, endocrine/metabolic, CNS, and cardiovascular.  相似文献   
72.
This study intended to discuss the interactive influence of the emergence, transformation and decline of the railway in Kaohsiung Port on urban development, the population, the activities and the economy in the region during the period of 1895–2010, from the perspectives of urban planning, railway development, population and industry. This study used the crossover analysis method, and used the factors of railway development and urban planning, within a fixed time period, to explore the chain dependence relationship among the industry, the population, the regional economy and the railway stations in Kaohsiung city. This study found that urban planning, economic development, railway development and industry have an interactive influence on the overall urban development. Urban planning promotes the rapid growth of the population, and economic development propels the growth and shaping of the regional economy, thus increasing employment opportunities. In addition, the railway development process moves forward with urban development.  相似文献   
73.
This article investigates the elasticity of different technology choices to energy efficiency and chemical oxygen demand/ammonia nitrogen emission reducing efficiency among 38 industries in China from 2008 to 2011. With data envelopment analysis, total-factor productivity growth, the common measure of technical progress, is divided into different parts: technical efficiency relative to the frontier, technology change and scale efficiency, which are regarded as three different choices of technological progress. For various industries, technology elasticity is quite different and the importance of different technical choices is diverse in the improvement of efficiency on energy saving and emission reduction. Policymakers could focus on the elasticity of different technical progress choices in various industries to improve energy and emission reduction efficiency.  相似文献   
74.
This paper examines the linkages between population growth and standard-of-living growth in 21 countries over the period of 1870–2013. We apply the bootstrap panel causality test proposed by Kónya (Econ Model 23:978–992, 2006), which accounts for both dependency and heterogeneity across countries. We find one-way Granger causality running from population growth to standard-of-living growth for Finland, France, Portugal, and Sweden, one-way Granger causality running from standard-of-living growth to population growth for Canada, Germany, Japan, Norway and Switzerland, two-way causality for Austria and Italy, and no causal relationship for Belgium, Brazil, Denmark, Netherlands, New Zealand, Spain, Sri Lanka, the UK, the USA, and Uruguay. Dividing the sample into two subsamples due to a structural break yields different results over the two periods of 1871–1951 and 1952–2013. Our empirical results suggest important policy implications for these 21 countries as the directions of causality differ across countries and time period.  相似文献   
75.
This study uses the newly developed Fourier unit root test advanced by Enders and Lee (2004, 2009) to investigate the time-series properties of real GDP (Gross Domestic Product) for five Southeastern European countries for the period from 1969 to 2009. The empirical results from several conventional unit root tests indicate that the per capita real GDP for all of the countries studied are non-stationary; however, when Enders and Lee (2004, 2009) Fourier unit root tests are conducted, one rejects the unit root hypothesis of real GDP per capita in all countries under study. These results have important policy implications for these five Southeastern European countries under study.  相似文献   
76.
This paper studies minimally-supported D-optimal designs for polynomial regression model with logarithmically concave (log-concave) weight functions. Many commonly used weight functions in the design literature are log-concave. For example, and exp(−x 2) in Theorem 2.3.2 of Fedorov (Theory of optimal experiments, 1972) are all log-concave. We show that the determinant of information matrix of minimally-supported design is a log-concave function of ordered support points and the D-optimal design is unique. Therefore, the numerically D-optimal designs can be constructed efficiently by cyclic exchange algorithm.  相似文献   
77.
Using new estimates of ad valorem equivalent of nontariff measures (NTMs) over time, this paper examines NTMs and tariffs’ relationship for a sample of 70 economies for 4,949 products at the 6‐digit harmonized system level over the period 2003–2015. A panel data methodology models the lagged adjustment of NTMs to tariffs, consistent with a causal relationship. Trade policy substitution is found when the models are estimated in both levels and changes; with this holding for both OECD and non‐OECD countries, but not for the agriculture sector in OECD countries. Overall, there is a fairly complete substitution between policy instruments in absolute terms.  相似文献   
78.
ABSTRACT

This study examines the four commonly tested hypotheses in hydroelectricity consumption – economic growth literature for 12 Asian countries. Our results from a recently developed hidden cointegration technique uncover rich and significant relationships between negative and positive components of the variables under consideration. In particular, we find evidence to support the neutrality hypothesis in five countries (Bangladesh, Indonesia, Pakistan, Philippines, and Thailand), the growth hypothesis in four countries (India, Japan, South Korea and Taiwan), and both growth and conservation hypotheses in three countries (China, Malaysia, and New Zealand). These findings suggest that appropriate economic policies should be elaborated on the basis of the country’s specific hydroelectricity consumption–growth nexus. Finally, our new evidence suggests that the lack of stable relationship between hydroelectricity consumption and economic growth documented in previous studies for some of these countries could be due to the failure to properly account for the nonlinearity property in the data.  相似文献   
79.
Conditional probability distributions seem to have a bad reputation when it comes to rigorous treatment of conditioning. Technical arguments are published as manipulations of Radon–Nikodym derivatives, although we all secretly perform heuristic calculations using elementary definitions of conditional probabilities. In print, measurability and averaging properties substitute for intuitive ideas about random variables behaving like constants given particular conditioning information.
One way to engage in rigorous, guilt-free manipulation of conditional distributions is to treat them as disintegrating measures—families of probability measures concentrating on the level sets of a conditioning statistic. In this paper we present a little theory and a range of examples—from EM algorithms and the Neyman factorization, through Bayes theory and marginalization paradoxes—to suggest that disintegrations have both intuitive appeal and the rigor needed for many problems in mathematical statistics.  相似文献   
80.
汪昶  马绝尘 《物流技术》2007,26(12):123-124
系统分析了戴尔公司供应链的运作情况,从信息和实物两个角度详细阐述了戴尔公司供应链的优越和高效。对戴尔公司采购、生产、销售和服务进行了完整的阐述。揭示了戴尔公司供应链系统的敏捷。  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