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11.
张文芳 《价值工程》2014,(28):312-313
通过对邯郸矿区陶一煤矿多年勘探和生产中获得的大量地质资料分析研究,得出该矿地质构造以正断层发育为主,断层分期形成及中小断层两盘呈反牵引的特点。并在此基础上结合大地及区域地质构造情况,进而探究了陶一井田古构造应力-应变场演化与断层形成间的关系。  相似文献   
12.
王保恒 《价值工程》2012,31(25):68-70
在钻井过程中应用扭矩传感器,通过对扭矩参数的解释,能正确指导工程施工,提高录井技术和资料解释水平,有利于快速发现油气显示,能够提高钻井效率、确保安全钻井。文章详细介绍了扭矩参数曲线的影响因素,扭矩参数曲线的形成过程,对不同的钻头事故形成了一般的判别规律。  相似文献   
13.
    
We investigate Carbon Kuznets Curves (CKC) relationships for advanced countries grouped in policy relevant groups – North America and Oceania, South Europe, North Europe – by means of various homogeneous, heterogeneous and shrinkage/Bayesian panel estimators. We try to provide an answer to the question ‘how sensitive are the CKC estimates to changes in the level of parameters' heterogeneity?’. We do find that in coherence with their ‘policy and economic’ commitment to carbon reductions and environmental market-based instruments implementation, bell shapes are present only for northern EU, which leads the group of advanced countries. The other two lag behind. We show for the first time that CKC shapes are present if we net out Europe of the southern and less developed countries. This is coherent with the Kuznets paradigm. The negative side of the tale is that they characterize a bunch of few countries. Other advanced countries lag behind and are far from reaching a CKC dynamics. Heterogeneous and Bayesian estimators clearly show this, with the EU presenting turning points closely around $13?000 per capita Gross Domestic Product (GDP). Heterogeneous panel estimates also show that for lagging countries presumed bell shapes turn into linear relationships. The stability of outcomes across models is stronger when we compare heterogeneous rather than homogeneous models. If it is compared with other studies, our analysis highlights a relative lower variability across specifications.  相似文献   
14.
    
We consider Bayesian inference about the dimensionality in the multivariate reduced rank regression framework, which encompasses several models such as MANOVA, factor analysis and cointegration models for multiple time series. The fractional Bayes approach is used to derive a closed form approximation to the posterior distribution of the dimensionality and some asymptotic properties of the approximation are proved. Finite sample properties are studied by simulation and the method is applied to growth curve data and cointegrated multivariate time series.  相似文献   
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16.
Both standard and robust methods are used here to estimate models of Engel curves for three household commodities, namely, food, transport, and tobacco and alcohol in Canada. The income elasticities of demand computed from the various methods differ significantly for the transport and tobacco-alcohol consumption where there are obvious outliers and zero expenditures problem. Robust estimators point to lower income elasticities and have better performance than the standard LS and Tobit estimator. These results are analyzed in the light of the information on finite-sample performance obtained in a previous Monte Carlo study. First version received: July 2000/Final version received: July 2001 RID="*" ID="*"  I wish to thank Victoria Zinde-Walsh, John Galbraith, Clint Coakley, two anonymous referees and an associate editor for helpful comments. I would also like to thank Anastassia Khouri for kindly providing the 1992 Family Expenditure Survey of Canada data.  相似文献   
17.
    
We study forward curves formed from commodity futures prices listed on the Standard and Poor’s-Goldman Sachs Commodities Index (S&P GSCI) using recently developed tools in functional time series analysis. Functional tests for stationarity and serial correlation suggest that log-differenced forward curves may be generally considered as stationary and conditionally heteroscedastic sequences of functions. Several functional methods for forecasting forward curves that more accurately reflect the time to expiry of contracts are developed, and we found that these typically outperformed their multivariate counterparts, with the best among them using the method of predictive factors introduced by Kargin and Onatski (2008).  相似文献   
18.
    
This paper considers semiparametric efficient estimation of conditional moment models with possibly nonsmooth residuals in unknown parametric components (θ) and unknown functions (h) of endogenous variables. We show that: (1) the penalized sieve minimum distance (PSMD) estimator can simultaneously achieve root-n asymptotic normality of and nonparametric optimal convergence rate of , allowing for noncompact function parameter spaces; (2) a simple weighted bootstrap procedure consistently estimates the limiting distribution of the PSMD ; (3) the semiparametric efficiency bound formula of [Ai, C., Chen, X., 2003. Efficient estimation of models with conditional moment restrictions containing unknown functions. Econometrica, 71, 1795–1843] remains valid for conditional models with nonsmooth residuals, and the optimally weighted PSMD estimator achieves the bound; (4) the centered, profiled optimally weighted PSMD criterion is asymptotically chi-square distributed. We illustrate our theories using a partially linear quantile instrumental variables (IV) regression, a Monte Carlo study, and an empirical estimation of the shape-invariant quantile IV Engel curves.  相似文献   
19.
Do demand curves for stocks slope down?: Evidence from aggregate data   总被引:1,自引:0,他引:1  
We examine whether the aggregate demand curve for stocks is downward sloping. As a proxy for aggregate demand, we use net outflows (dividends plus repurchases less net issues) from the stock market scaled by the previous year's market capitalization. To disentangle the information and price pressure effects from the demand curve effects, we use an information-free demographic variable as an instrument and look at the relation between annual changes in aggregate demand and excess market return. We find that information-free changes in the annual aggregate demand for stocks do not lead to changes in the annual excess market return. This finding supports long-term horizontal demand curves for stocks.  相似文献   
20.
Transitioning towards a sustainable energy system requires the large-scale introduction of novel energy demand and supply technologies. Such novel technologies are often expensive at the point of their market introduction but eventually become cheaper due to technological learning. In order to quantify potentials for price and cost decline, the experience curve approach has been extensively applied to renewable and non-renewable energy supply technologies. However, its application to energy demand technologies is far less frequent. Here, we provide the first comprehensive review of experience curve analyses for energy demand technologies. We find a widespread trend towards declining prices and costs at an average learning rate of 18 ± 9%. This finding is consistent with the results for energy supply technologies and for manufacturing in general. Learning rates for individual energy demand technologies are symmetrically distributed around the arithmetic mean of the data sample. Absolute variation of learning rates within individual technology clusters of 7 ± 4%-points and between technology clusters of 7 ± 5%-points both contribute to the overall variability of learning rates. Our results show that technological learning is as important for energy demand technologies as it is for energy supply technologies. Applying the experience curve approach to forecast technology costs involves, however, unresolved uncertainties, as we demonstrate in a case study for the micro-cogeneration technology.  相似文献   
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