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   47249篇
  免费   1900篇
  国内免费   1009篇
财政金融   3549篇
工业经济   1808篇
计划管理   10506篇
经济学   8513篇
综合类   8185篇
运输经济   423篇
旅游经济   733篇
贸易经济   5614篇
农业经济   3677篇
经济概况   7150篇
  2024年   76篇
  2023年   656篇
  2022年   713篇
  2021年   1088篇
  2020年   1355篇
  2019年   930篇
  2018年   866篇
  2017年   1134篇
  2016年   1147篇
  2015年   1384篇
  2014年   3348篇
  2013年   3473篇
  2012年   4016篇
  2011年   4959篇
  2010年   3785篇
  2009年   3480篇
  2008年   3660篇
  2007年   3305篇
  2006年   3008篇
  2005年   2215篇
  2004年   1593篇
  2003年   1230篇
  2002年   734篇
  2001年   660篇
  2000年   445篇
  1999年   226篇
  1998年   140篇
  1997年   113篇
  1996年   91篇
  1995年   55篇
  1994年   53篇
  1993年   39篇
  1992年   40篇
  1991年   18篇
  1990年   10篇
  1989年   9篇
  1988年   12篇
  1987年   4篇
  1986年   10篇
  1985年   23篇
  1984年   21篇
  1983年   10篇
  1982年   9篇
  1981年   4篇
  1979年   3篇
  1978年   6篇
  1977年   1篇
  1973年   1篇
排序方式: 共有10000条查询结果,搜索用时 390 毫秒
81.
Previous empowerment research has focused on subordinate perceptions of empowering leadership and its outcomes. Met‐expectations theory suggests that subordinate expectations of leader behaviours are essential in forming their a posteriori evaluations. To address the lack of investigation of individual expectations in the empowerment literature, in this study, we explore how subordinates' empowerment expectations and perceptions combine to influence their job satisfaction and psychological empowerment based on three alternative, theoretically derived met‐expectation models, namely, the disconfirmation model, the ideal‐point model, and the experiences‐only model. The results of a 2‐stage study of 114 respondents indicate that employees are more satisfied with their work when perceived empowerment exceeds expectations. However, both empowerment perceptions and expectations positively contribute to higher psychological empowerment. We then discuss implications and directions for future research.  相似文献   
82.
我国秸秆综合利用面临形势与对策研究   总被引:1,自引:0,他引:1  
[目的]为加快推动秸秆资源化利用,促进农业绿色发展。[方法]文章在系统梳理我国秸秆综合利用政策文件、相关文献的基础上,全面分析了我国农作物秸秆禁烧和综合利用的发展阶段,提出了秸秆利用面临的形势和存在的主要问题。[结果]我国秸秆综合利用从时间序列上,可以划分为起步阶段、强力推进阶段和攻坚阶段。城镇化的快速推进、农村能源结构的调整、农业供给侧结构性改革的实施、农作物季节矛盾突出等,成为秸秆综合利用面临的新形势、新挑战。当前推进秸秆综合利用存在四大方面问题:秸秆还田成本较高,区域技术规范和技术适宜性缺乏;受"成本地板"和"价格天花板"双重挤压,秸秆产业化利用发展困难;秸秆收储运成本高,技术装备水平低,用地、运输问题尚未解决,收储运体系建设不健全;关键性政策工具尚未破题,缺乏普惠性、针对性的资金扶持。[结论]针对形势与问题,提出了推进秸秆资源化利用的4条对策建议:开展县域秸秆全量化利用、分区施策确定秸秆利用方向、加强政策工具集成创设、扩大试点示范引导。  相似文献   
83.
程欣 《水利经济》2018,36(6):48-52
以城市自来水水质事故致因为研究视角,首先识别供水水质风险因素,并从单、双及多因素角度分析供水水质风险因素间的耦合关系,再借助N-K模型对2008—2017年全国所发生的362起城市重大供水水质风险耦合度进行度量。结果表明:城市自来水供应动态系统中,水质风险率随着参与耦合的风险因素的增多而增加;管理因素风险是水质风险的内因,风险管控是规避水质风险的关键;环境因素风险对水质事故的发生起推动作用。  相似文献   
84.
Coping with asymmetric information plays a major role in successful small business lending. Our purpose is to determine if small business applicants report their income information correctly when requesting a loan. We use a randomised controlled trial bogus pipeline experiment, established during a typical cash‐flow analysis of a bank for small businesses in the Philippines. The bogus pipeline approach is commonly applied in social science and aims to increase the rate of truth telling by informing participants that answers will be verified by a lie detector. The experimental data, which include 243 observations of credit clients that are mainly from the agricultural and food value chain, served to identify asymmetric information. Additionally, debtors’ repayment behaviour for approved loans was observed by the bank. Our results indicate that loan applicants of the treatment group report lower incomes, an effect which is most pronounced in lower income quantile. Our analyses also reveal higher loan delinquencies in the control group.  相似文献   
85.
The aim of this paper is to examine valuer judgement behaviour, by exploring the manifestation of task complexity in Dutch commercial valuation practice. For this purpose, we adopted a grounded theory approach and undertook 18 in-depth interviews with senior valuation professionals across the Netherlands. Our findings indicate a strong presence of situational task complexity in commercial valuation practice, as professionals operating in large valuation teams perceive different elements of task complexity throughout commercial valuation practice in comparison to peers working in small valuation teams or self-employed valuers. Further, coping strategies used to deal with task complexity vary substantially by type of valuer as well. From our data, we deducted three types of task environment constructs in which valuers operate, which basically represent the various levels of professional standards required by clients as well as organisational settings composed to meet client standards. As such, we found that task environment settings strongly coincide with perceptions of task complexity. The presence of situational task complexity in commercial real estate valuation practice points to the need for customisation of professional valuer’s development programs to facilitate valuers to deal with task complexity in different stages of valuation practice and hence contribute to advancing valuer judgement skills.  相似文献   
86.
党的十九大报告提出了“实施乡村振兴战略”。乡村振兴是“中国梦”不可或缺的组成部分,城市化进程中的乡村衰落现象不容忽视,乡村问题的解决关系到乡村振兴战略能否实现和现代乡村能否建成。为此,剖析了我国乡村衰落的成因,探索了乡村振兴战略落实的办法,提出了现代乡村建设的可能路径。  相似文献   
87.
Two-part models based on generalized linear models are widely used in insurance rate-making for predicting the expected loss. This paper explores an alternative method based on quantile regression which provides more information about the loss distribution and can be also used for insurance underwriting. Quantile regression allows estimating the aggregate claim cost quantiles of a policy given a number of covariates. To do so, a first stage is required, which involves fitting a logistic regression to estimate, for every policy, the probability of submitting at least one claim. The proposed methodology is illustrated using a portfolio of car insurance policies. This application shows that the results of the quantile regression are highly dependent on the claim probability estimates. The paper also examines an application of quantile regression to premium safety loading calculation, the so-called Quantile Premium Principle (QPP). We propose a premium calculation based on quantile regression which inherits the good properties of the quantiles. Using the same insurance portfolio data-set, we find that the QPP captures the riskiness of the policies better than the expected value premium principle.  相似文献   
88.
将水权交易和面源污染控制有机结合,以种植面积、农业用水定额、污染物浓度为约束条件,运用边际分析方法建立农户灌溉施肥行为模型,分析水权交易和排污控制对农户行为的影响。结果表明:灌溉用水量与农作物价格成正相关,与交易水价和边际灌溉成本成负相关;一定范围内肥料施用量与农作物价格成正相关,与边际施肥成本或边际环境成本成负相关。模型证明,当农业用水定额内水权可交易时,水市场的存在和水价政策将激励农户减少灌水量,节约用水。  相似文献   
89.
This study analyses the economics of conservation tillage (CT) with respect to its effect on maize yield and chemical fertiliser, herbicide, and female and male labour demand. We estimate production and input demand functions using seemingly unrelated regressions on plot‐level cross‐sectional farm household data collected in the north‐west of Ethiopia. A two‐step control function is applied to address potential endogeneity bias due to the inclusion of the CT adoption decision as an explanatory variable. Our results show that CT increases maize yield and chemical fertiliser demand. Additionally, the results show that the adoption of CT reduces female and male labour required for crop production. However, this is achieved through the increased use of herbicides, which might have an undesirable health and environmental effects.  相似文献   
90.
空气质量指数(AQI)在波动中既具有整体的时间序列线性特征和明显的季节性波动周期,又具有多种因素影响的不确定性,为了提高AQI的预测精度,基于Ri386 3.3.3和Matlab R2014a两种编程软件,提出了一种同时具有线性和非线性的复合特征的时间序列预测模型——SARIMA-SVR组合模型。以太原市2014年1月—2019年7月的AQI月均值数据为基础,利用SARIMA时间序列模型进行线性预测,利用SVR模型对残差进行非线性预测,加和得到组合预测模型的预测结果,分析比较SARIMA,SVR和SARIMA-SVR这3种模型的预测结果和平均绝对百分比误差。结果表明,组合预测模型发挥了2种模型各自的优势,相较于单一预测模型的预测结果而言,其预测精度更高,稳定性更好。通过此模型得到的空气质量预测结果不仅可为人们的日常生活提供指导,而且可为大气污染的防治工作提供科学依据和借鉴意义。  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