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   20900篇
  免费   504篇
  国内免费   344篇
财政金融   1269篇
工业经济   1178篇
计划管理   5518篇
经济学   3421篇
综合类   2138篇
运输经济   353篇
旅游经济   715篇
贸易经济   2742篇
农业经济   2008篇
经济概况   2406篇
  2024年   93篇
  2023年   345篇
  2022年   368篇
  2021年   542篇
  2020年   727篇
  2019年   510篇
  2018年   490篇
  2017年   678篇
  2016年   607篇
  2015年   674篇
  2014年   1593篇
  2013年   1981篇
  2012年   1732篇
  2011年   2142篇
  2010年   1540篇
  2009年   1328篇
  2008年   1405篇
  2007年   1244篇
  2006年   1023篇
  2005年   805篇
  2004年   555篇
  2003年   322篇
  2002年   208篇
  2001年   189篇
  2000年   141篇
  1999年   82篇
  1998年   91篇
  1997年   55篇
  1996年   53篇
  1995年   44篇
  1994年   39篇
  1993年   21篇
  1992年   21篇
  1991年   19篇
  1990年   10篇
  1989年   8篇
  1988年   5篇
  1987年   4篇
  1986年   9篇
  1985年   11篇
  1984年   12篇
  1983年   10篇
  1982年   7篇
  1981年   1篇
  1980年   2篇
  1979年   2篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
851.
In this paper, the validity of vignette analyses of various forms of deviant behavior in the presence of opportunities is analyzed on the basis of ideas derived from cognitive psychology. Abelson’s Script Theory together with insights into human memory of visual and verbal information, allow the assumption that vignette analyses using visual stimuli are valid measures of deviant behavior in particular. The study includes an empirical examination of these ideas (n = 450). Nonparticipant observations and vignette analyses with visual and verbal material were carried out with regard to three forms of deviant behavior occurring in the presence of opportunities presenting themselves in everyday life. Observed and self-reported frequencies of deviant behavior or deviant intentions were counted and cross-tabulated. Log-linear analyses with dummy coding using observation data as reference category were run. Data analyses yielded the result that frequencies of deviant behavior were related to the techniques of data collection under consideration. Especially vignette analyses of the return of ‘lost letters’ that use both visual and verbal stimuli overestimate ‘actual’ (i.e. observed) return rates. This result is discussed with regard to the underlying methodological assumptions as well as its implications.  相似文献   
852.
薄壁箱梁结构由于其结构轻,刚度大,在结构工程中得到了广泛的应用.钢筋锈蚀是影响混凝土结构耐久性的重要因素,为了正确评估钢筋锈蚀后构件的裂缝发展情况,本文利用大型有限元软件ANSYS通过对锈蚀钢筋混凝土薄壁箱梁的非线性分析,得到了锈蚀构件的裂缝的变化规律.  相似文献   
853.
吕国兵 《基建优化》2007,28(5):188-190
概率预测是评估建筑工程事故风险的基本手段,基于对建筑工程风险因素的综合分析,确定了建筑工程风险源因素FTA(Fault Tree Analysis)分析方法,目的在于为建筑工程概率预测方法的研究提供一种新的尝试,故为采取合理的防治技术措施在理论上、方法上提供有益的指导,并最终减少和控制建筑工程事故的发生.  相似文献   
854.
机场净空区超高障碍物风险性分析   总被引:1,自引:0,他引:1  
针对机场净空区超高障碍物较多的现象,对飞机飞行航迹进行了测试,提出了净空安全系数的概念,结合实际测试数据,应用统计分析原理,得出了净空安全系数的概率分布规律.以安全系数的分布规律为基础,对不同超高障碍物的风险性进行了分析,并提出了按照不同安全系数划分障碍物限制高度的思路,最后给出了不同类型机场净空安全系数的建议值,对各类机场净空管理和障碍物限制面的确定具有重要参考价值.  相似文献   
855.
王栋栋  徐继英 《基建优化》2007,28(1):98-100
房地产市场的和谐是社会主义和谐社会的重要组成部分。我国已经进入老龄化社会,老龄社区不仅可以给老龄人群提供居所,还可以给开发商提供商机,对整个社会和房地产行业都很有利。本文提出了老龄社区开发应注意的几个问题。在多个开发方案的评价中,利用灰色关联分析的决策模型对其进行综合评价,最终得到了满意的结果。  相似文献   
856.
Abstract

Background and aims: A wide range of treatment options are available for hepatocellular carcinoma (HCC), including systemic treatment with tyrosine kinase inhibitors (TKIs) such as sorafenib and lenvatinib, immunotherapies, locoregional therapies such as selective internal radiation therapy (SIRT) and treatments with curative intent such as resection, radiofrequency ablation and liver transplantation. Given the substantial economic burden associated with HCC treatment, the aim of the present analysis was to establish the cost of using SIRT with SIR-Spheres yttrium-90 (Y-90) resin microspheres versus TKIs from healthcare payer perspectives in France, Italy, Spain and the United Kingdom (UK).

Methods: A cost model was developed to capture the costs of initial systemic treatment with sorafenib (95%) or lenvatinib (5%) versus SIRT in patients with HCC in Barcelona Clinic Liver Cancer (BCLC) stages B and C. A nested Markov model was utilized to model transitions between progression-free survival (PFS), progression and death, in addition to transitions between subsequent treatment lines. Cost and resource use data were identified from published sources in each of the four countries.

Results: Relative to TKIs, SIRT with SIR-Spheres Y-90 resin microspheres were found to be cost saving in all four country settings, with the additional costs of the microspheres and the SIRT procedure being more than offset by reductions in drug and drug administration costs, and treatment of adverse events. Across the four country settings, total cost savings with SIR-Spheres Y-90 resin microspheres fell within the range 5.4–24.9% and SIRT resulted in more patients ultimately receiving treatments with curative intent (4.6 vs. 1.4% of eligible patients).

Conclusion: SIR-Spheres Y-90 resin microspheres resulted in cost savings relative to TKIs in the treatment of unresectable HCC in all four country settings, while increasing the proportion of patients who become eligible for treatments with curative intent.  相似文献   
857.
Microfinance targets women and uses loan provision as a tool for empowerment, which translates into better household nutrition, improved education, and a scale down of domestic violence. However, ethnic discrimination in microfinance may exist in countries with a segregated indigenous population. We assessed this possibility with a field experiment in Bolivia. The controlled laboratory experiment evaluated whether credit officers rejected microloan applications based on the interaction effect of ethnicity and gender of potential borrowers. Point estimates of a Bayesian mixed‐effects logistic regression, estimated with the experimental data, indicate that nonindigenous women have double the chance of loan approval, but indigenous women have only 1.5 times the chance of loan approval when compared with men. While the findings about gender are limited, the evidence for the interaction of gender and ethnicity is more robust and suggests the existence of positive taste‐based discrimination favorable for nonethnic women in Bolivia. We conclude that the affirmative actions towards women promoted by development agencies and microfinance institutions must not overlook ethnicity as an important factor for financial policies of sustainable development. In practice, these policies should be aimed at identifying and reducing both social desirability bias and the structural barriers to financial inclusion that indigenous women may face when trying to obtain access to a loan.  相似文献   
858.
郑季良 《技术经济》2020,39(10):38-44
制造企业的内部资源有效配置是关系到转型升级成效的内在问题,但资源配置的组态如何影响转型升级成效尚没有得到充分研究。文章将企业的资源要素分为研发投入、人才水平、发展潜力以及客户集中度四个方面,将企业规模设为调节变量,运用模糊集定性比较分析方法,对31家制造企业进行实证研究,得到资源配置的四种有效组态形式为:高抗风险型、高创新投入型、高市场地位型以及紧密客户关系型。研究结论证实了转型升级资源配置组态效应的客观存在,既丰富了企业转型升级理论及方法,也为企业转型升级的路径选择及有效性分析提供了的启示和参考。  相似文献   
859.
ABSTRACT

A comparative analysis of population dynamics worldwide contributes to profile distinctive demographic and economic trajectories of urban growth, discriminating processes of settlement concentration or dispersion under sequential cycles of urbanization. However, a wide-ranging characterization of urban cycles based on demographic dynamics worldwide is still missing. The present work is aimed at filling such a gap analysing long-term changes (1950–2030) in annual population growth rate of 1691 urban agglomerations with more than 300,000 inhabitants in 74 world countries. Results of this study indicate that metropolitan growth worldwide was associated with largely variable rates of population growth, highly positive before 2000 and progressively reducing over recent decades. Despite important differences at continental (and country) scale, demographic expansion of urban agglomerations showed two contrasting phases with a break point in the 1980s denoting a progressive reduction in spatial heterogeneity of population growth rates and a moderate slowdown in demographic dynamics. Intensity of urban expansion and spatial heterogeneity in population growth rates across metropolitan agglomerations evidences a trade-off between fast and slow demographic dynamics. These findings can be better understood to support theories of sequential city growth, making a suitable contribution to policy making, especially in countries where urban population is expanding more rapidly.  相似文献   
860.
ABSTRACT

The argument over the effects of financial structures on economic growth remains unsettled. This study, therefore, compares the dynamic correlation and lead–lag relationship between the different financial approaches within the banking sector (that is, traditional bank loans versus innovative financial leasing) and economic growth. We employ a continuous wavelet analysis using time-series data from 1982–2017 from the US (the world’s largest developed country) and China (the world’s largest developing country). The empirical results show that (1) episodes of significant correlation usually emerge during periods of reform, crisis or policy implementation; and (2) in China, traditional banking promotes economic growth in the long term, while the real economy only imputes the evolution of banks during critical economic reforms in the short term. Meanwhile, financial leasing could only promote the development of the real economy under suitable regulation; and (3) in the US, before the crises, the irrational growth of the real economy could increase bank assets, while during the crises, the traditional banking approach harms economic growth, and after the crises, financial leases play an important role in recovery. Therefore, we suggest that policymakers should establish adequate policies and regulations to solve the situation.  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