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   1865篇
  免费   36篇
  国内免费   6篇
财政金融   396篇
工业经济   38篇
计划管理   473篇
经济学   461篇
综合类   95篇
运输经济   28篇
旅游经济   20篇
贸易经济   211篇
农业经济   60篇
经济概况   125篇
  2024年   2篇
  2023年   28篇
  2022年   34篇
  2021年   62篇
  2020年   78篇
  2019年   84篇
  2018年   57篇
  2017年   76篇
  2016年   81篇
  2015年   55篇
  2014年   84篇
  2013年   198篇
  2012年   101篇
  2011年   114篇
  2010年   84篇
  2009年   114篇
  2008年   101篇
  2007年   102篇
  2006年   94篇
  2005年   75篇
  2004年   62篇
  2003年   58篇
  2002年   34篇
  2001年   22篇
  2000年   26篇
  1999年   14篇
  1998年   13篇
  1997年   9篇
  1996年   6篇
  1995年   6篇
  1994年   4篇
  1993年   6篇
  1992年   3篇
  1991年   6篇
  1990年   2篇
  1989年   1篇
  1988年   1篇
  1987年   1篇
  1986年   2篇
  1985年   1篇
  1984年   5篇
  1982年   1篇
排序方式: 共有1907条查询结果,搜索用时 27 毫秒
101.
Objective: To estimate, from the perspective of the German statutory health insurance, the cost utility of allogeneic stem cell transplantation with matched unrelated donor (MUD-SCT) in newly diagnosed, chronic-phase chronic myeloid leukaemia (CML) patients aged 40 years or younger, relative to the treatment with imatinib.

Methods: The incremental cost-effectiveness ratio (ICER) of the additional cost of imatinib versus MUD-SCT per quality-adjusted life year (QALY) gained was chosen as a target assessment. ICER was quantified using a Markov cohort modelling approach. The evaluation encompassed 5 years of treatment with either approach, and only direct medical costs (in €, year 2005) were considered.

Results: There were incremental costs of €77,410 for imatinib therapy per QALY gained versus MUD-SCT. No strategy was clearly dominant; on average, during 5 years, cost savings of €63,433 were obtained and 0.82 QALY lost by SCT compared to treatment with imatinib. QALYs gained in CML patients with either treatment resulted in considerable cost to the third-party payer in Germany. The results were particularly sensitive to the price of imatinib.

Conclusions: The analysis finds that imatinib is more costly but more effective (as measured in QALYs) over a 5-year time horizon. The resulting ICER of €77,410 per QALY is higher than commonly cited thresholds. The cost utility of MUD-SCT to treat CML in patients with a European Group for Blood and Marrow Transplantation score ≤ to 2 compares with that of the imatinib strategy.  相似文献   
102.
Abstract

Objective:

The cost-effectiveness of renal replacement therapy (RRT) is affected by the composition of treatment. This study aimed to estimate the costs and outcomes associated with changing the composition of RRT modality over time.

Methods:

By using clinical and cost data from a systematic review, a Markov model was developed to assess the costs and benefits of the four main treatments available for RRT in Japan. The model included direct health service costs and quality-adjusted life years (QALY). Sensitivity analyses were performed to assess the robustness of the results.

Results:

Over the 15-year period of the model, the current composition of RRT (i.e., the base composition of RRT) was $84,008/QALY. The most cost-effective treatment was when the likelihood of a living donor transplant was increased by 2.4-times ($70,581/QALY). Compared with the base composition of RRT, dominant treatments with respect to cost-effectiveness were when the likelihood of a deceased donor transplant was increased by 22-times and when the likelihood of a pre-emptive living donor transplant was increased by 2.4-times. Little difference was found between these two treatments. One-way sensitivity analysis did not change the cost effectiveness except for costs of chronic hemodialysis and a living donor transplant in subsequent years.

Limitations:

It is difficult to increase the rate of transplant overall in the shorter term nationally and internationally.

Conclusions:

Appropriate distribution of all transplant options and hemodialysis is necessary to achieve the most cost-effective solution.  相似文献   
103.
Abstract

Objective:

The aim of this study was to assess cost-effectiveness of the different Disease Modifying Drugs (DMD) used as first-line treatments (interferons IM IFNβ-1a, SC IFNβ-1a, SC IFNβ-1b, and glatiramer acetate, GA) in Remitting-Relapsing Multiple Sclerosis (RRMS) in Spain.

Methods:

A Markov model was developed to simulate the progression of a cohort of patients with RRMS, during a period of 10 years. Seven health states, defined by the Expanded Disability Status Scale (EDSS), were considered in the model. Patients with an EDSS score less than 6.0 were assumed to be treated with one of the DMD. In addition, all patients were assumed to receive symptomatic treatment. The monthly transition probabilities of the model were obtained from the literature. The analysis was performed from the societal perspective, in which both direct and indirect (losses in productivity) healthcare costs (€, 2010) were included. A discount rate of 3% was applied to both costs and efficacy results.

Results:

GA was the less costly strategy (€322,510), followed by IM IFNβ-1a (€329,595), SC IFNβ-1b (€ 333,925), and SC IFNβ-1a (€348,208). IM IFNβ-1a has shown the best efficacy results, with 4.176 quality-adjusted life years (QALY), followed by SC IFNβ-1a (4.158 QALY), SC IFNβ-1b (4.157 QALY), and GA (4.117 QALY). Incremental costs per QALY gained with IM IFNβ-1a were €?1,005,194/QALY, €?223,397/QALY, and €117,914/QALY in comparison to SC IFNβ-1a, SC IFNβ-1b, and GA, respectively.

Conclusions:

First-line treatment with GA is the less costly strategy for the treatment of patients with RRMS. Treatment with IM IFNβ-1a is a dominant strategy (lower cost and higher QALY) compared with SC IFNβ-1a and SC IFNβ-1b. However, IM IFNβ-1a is not a cost-effective strategy vs GA, because incremental cost per QALY gained with IM IFNβ-1a exceeds the €30,000 per QALY threshold commonly used in Spain.

Limitations:

The highly-restrictive inclusion criteria of clinical trials limits generalization of the results on efficacy to all patients with multiple sclerosis. Availability of data for head-to-head comparisons is associated with the use of information from clinical trials.  相似文献   
104.
根据时间序列宽平稳的定义,本文认为,平滑转换自回归模型的序列不是宽平稳序列,利用ADF统计量检验其平稳性是没有意义的;其次,依据马尔科夫链的遍历性,我们认为,STAR模型的序列是严平稳序列,且通过对模型系数的联合取值的限制保证了模型的平稳性。以一阶对数平滑转换自回归模型为例,其平稳的条件是,β与r符号相反,且|β+r|<1,β可以等于1,也可以绝对值小于1。  相似文献   
105.
从理论上分析了全产业链创新网络结构特点以及核心企业行为模式与创新绩效的关系,提出相关假设;从开放性的2个维度,即开放广度和开放深度量化核心企业开放式创新的行为模式。依据偏最小二乘法,将结构和行为模式的表征变量作为自变量,创新绩效的4个表征变量作为因变量,进行交叉检验;最后选取1个主成分进行回归分析,检验理论假设。  相似文献   
106.
知识是技术的源泉,知识供应链是技术创新中知识供应的有效通道。应用知识供应链开发新产品包括强化知识供应链,加速知识流动转化和反馈知识应用绩效,以及保持知识循环等方面。快速成型技术在产品创新知识供应链中,加快了知识流动,促进了隐性知识显性化,反馈了知识创新的作用绩效,加速了知识螺旋循环,有效地支持了产品创新。  相似文献   
107.
Heuristic algorithms have been widely used to provide computationally feasible means of exploring the cost effective balance between grid versus off grid sources for universal electrification in developing countries. By definition in such algorithms however, global optimality is not guaranteed. We present a computationally intensive but globally optimal mixed integer non-linear programming (MINLP) model for electricity planning and use it in a Monte Carlo simulation procedure to test the relative performance of a widely used heuristic algorithm due to [28]. We show that the overall difference in cost is typically small suggesting that the heuristic algorithm is generally cost effective in many situations. However we find that the relative performance of the heuristic algorithm deteriorates with increasing degree of spatial dispersion of unelectrified settlements, as well as increasing spatial remoteness of the settlements from the grid network, suggesting that the effectiveness of the heuristic algorithm is context specific. Further, we find that allocation of off grid sources in the heuristic algorithm solution is often significantly greater than in the MINLP model suggesting that heuristic methods can overstate the role of off-grid solutions in certain situations.  相似文献   
108.
为进一步了解太赫兹光波与生物介质的相互作用机理,采用蒙特卡罗法(MCM)对太赫兹光波在非均匀生物介质中的传播进行模拟计算,得到了太赫兹光波在非均匀生物介质表面的漫反射光强分布曲线.数据显示了漫反射光强分布与生物介质中异物的大小(R)及位置(D)的关系.  相似文献   
109.
中小企业对经济的贡献率越来越大,然而中小企业融资难的问题也越来越突出。本文设想多个企业联合建立共同基金以便于解决各自企业融资难的问题,并基于此思想而构造一种新融资模式。  相似文献   
110.
This paper aims to investigate the crisis linkage and transmission channels within the housing, stock, interest rate and the currency markets in the U.S. and China in the past decade since the 2008 Subprime Mortgage Crisis. Two hybrid models, namely the SWARCH-EVT-Copula and the Bivariate SWARCH-EVT models, are proposed and applied in order to take into account (A) the high/low volatility regimes, (B) the interdependence structure inherited from the joint tail behaviours, as well as, (C) the risk spillover dynamics among financial sectors during market turmoils. We empirically show that the housing and stock markets share the strongest linkage and play central roles in the spreading of shocks. With a highly integrated system, the American financial sectors are under greater exposure to risk contagion and systemic risk during crises than the Chinese markets. Nevertheless, the exchange rate risk of Renminbi remains at an intensive level since its “crawl-like arrangement” and leads to increasing co-movements in the stock and interest rate markets since 2014.  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