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61.
Abstract

Given that ostracism is a common occurrence in the workplace, scholars and practitioners alike have identified its range of negative effects. This study aims to examine the association between workplace ostracism and burnout level as well as the moderating effects of job self-determination and employees’ future time orientation, using a survey questionnaire. This was completed by a total of 248 employees from a hotel group. We hypothesized that: (a) workplace ostracism was positively associated with burnout; (b) this positive relationship was contingent upon job self-determination such that the relationship was weaker for higher, rather than lower, job self-determination; and (c) the positive relationship was also contingent upon employees’ future time orientation such that the relationship was weaker for employees who have higher, rather than lower future time orientation. Results confirm all three hypotheses.  相似文献   
62.
考虑了牵引车空驶、带空挂车行驶和带重挂车行驶所引起的成本差异,定义了牵引车运行成本的概念,将总运行成本最小作为调度方案优劣的判别指标,并同时考虑牵引车数量最少。将牵引任务分为四种类型,定义了任务链、虚拟任务、链内交叉和链间交叉的概念,提出了一种求解该类单车场甩挂运输车辆调度无时间窗约束的启发式算法,包括初始调运方案、链内优化、空车调运交叉、牵引车数量优化和链间交叉。最后给出了仿真算例,算法优化后的最终方案与初始方案相比,牵引车数量减少,总运行成本降低,验证了算法的有效性和可行性。  相似文献   
63.
周扬 《价值工程》2014,(32):37-39
风电功率的随机波动被认为是对电网带来不利影响的主要因素。研究风电功率的波动特性,对改善风电预测精度与克服风电接入对电网的不利影响都有重要意义。本文通过对30天的风电数据加总,求得15min级的风电功率数据,提出了基于ARIMA模型的风电功率的预测模型。通过对数据进行单步预测取得较好的预测结果,说明ARIMA(1,1,1)模型能够较好的拟合原始数据。给风电功率的预测提供了新的思路。  相似文献   
64.
路文娟 《价值工程》2014,(13):19-20
带式输送机是煤矿生产必不可少的生产设备,然而随着工作面的结束,胶带的回收则是一项费力、费时的工作,此种简易的收放带装置则能通过盘车载着绞车,再用四根单体液压支柱支着顶板固定实现胶带的快速回收,不仅省时省力,避免胶带用人力回收造成的破损,而且移动方便,造价低,回收胶带成卷整齐。  相似文献   
65.
This paper uses three classes of univariate time series techniques (ARIMA type models, switching regression models, and state-space/structural time series models) to forecast, on an ex post basis, the downturn in U.S. housing prices starting around 2006. The performance of the techniques is compared within each class and across classes by out-of-sample forecasts for a number of different forecast points prior to and during the downturn. Most forecasting models are able to predict a downturn in future home prices by mid 2006. Some state-space models can predict an impending downturn as early as June 2005. State-space/structural time series models tend to produce the most accurate forecasts, although they are not necessarily the models with the best in-sample fit.  相似文献   
66.
信息共享条件下的牛鞭效应降低方法   总被引:4,自引:0,他引:4  
尤建  朱峰 《物流科技》2004,27(8):40-43
牛鞭效应是供应链管理中一个常见的现象,在寻求解决降低和消除供应链中这一现象中,普遍提出了信息共享来降低和消除牛鞭效应。即使在信息共享的条件下,我们依然不能完全消除牛鞭效应,以及供应链中各个主体的危害。本文从lee,etc.在解释供应链存在的需求预测所带来的牛鞭效应原因出发,寻找信息共享条件下降低牛鞭效应的可行途径。  相似文献   
67.
余晓钟 《价值工程》2004,23(3):115-117
工期(T)、质量(Q)和成本(C)是项目建设中,决策者最为关注的三个目标,它们在不同的工程项目中表现出不同的决策要求。本文研究了T、Q、C三者发生不同变化时的决策情形,并给出了相应的决策优化思路和方法,为项目决策人提供了一定的决策参考依据。  相似文献   
68.
Although the Cointegration Theory was founded by the C.W.J Granger and other economists in the 1980s, it was not widely used in China until C.W.J Granger was awarded with Nobel Prize in 2003. Since then, a lot of economic papers introducing or applying Cointegration Theory have emerged, but the phenomenon of misuse of this theory possibly arose at the same time. Based on some of these papers obtained from web site (www.cnki.net), this paper explores the applications of Cointegration Theory in China and draws some initial conclusions. Most of these applications are reasonable, but some of them are a bit blindfold or even contradictory in conclusions, which indicates that the overall application quality has a large room to get improved and should be paid more attention by academe.  相似文献   
69.
Forecasting economic time series with unconditional time-varying variance   总被引:1,自引:0,他引:1  
The classical forecasting theory of stationary time series exploits the second-order structure (variance, autocovariance, and spectral density) of an observed process in order to construct some prediction intervals. However, some economic time series show a time-varying unconditional second-order structure. This article focuses on a simple and meaningful model allowing this nonstationary behaviour. We show that this model satisfactorily explains the nonstationary behaviour of several economic data sets, among which are the U.S. stock returns and exchange rates. The question of how to forecast these processes is addressed and evaluated on the data sets.  相似文献   
70.
The aim of this study was to model and characterize the psychologicalprocesses that underlie the dynamics of global self-esteem and physicalself over time. Twice a day for 228 consecutive days, seven participantscompleted a short inventory (PSI-6, Ninot et al., 2001) measuring sixsubjective dimensions: global self-esteem, physical self-worth, physicalcondition, sport competence, physical strength, and attractive body.Each series was modeled by means of ARIMA procedures. The resultsshowed that a simple moving average model provided a satisfactoryaccount for the dynamics of all series. This model suggests that acombination of two opposite processes underlies the dynamics ofself-concept: preservation, which tends to restore the previousvalue after a disturbance, and adaptation, which tends to inflectthe series in the direction of the perturbation.  相似文献   
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