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五强溪水电站主体工程混凝土浇筑垂直运输在大坝两岸分高、低层布置4台平移式20t缆索起重机。其中2台高缆从德国引进,属世界上首次采用全遥控的缆机,同时也是国内塔架最高的缆机;2台低缆属我国目前自行设计制造安装的规格最大、速度最高的缆机。 相似文献
13.
Jonas Agell 《The Scandinavian journal of economics》2004,106(3):437-452
Do incentives differ between large and small organizations? Results from a representative survey of compensation managers are used to shed light on the issues. I find that (i) small establishments rely less on pecuniary incentives, and have a significantly more hostile attitude towards incentive schemes based on competition and relative rewards; (ii) large units are more vulnerable to mechanisms of efficiency wages, effects that remain even after controlling for differences in monitoring ability; (iii) large units are more prone to indicate that negative reciprocity is important, and that their employees care about relative pay. I argue that these findings fit with behavioral stories of incentives and motivation, in particular those stressing group interaction effects, inequity aversion and gift exchange. 相似文献
14.
在竹坑水库大坝安全鉴定中,认真分析了该工程存在的主要问题,并针对大坝的结构稳定和渗流稳定作了详细的分析论证. 相似文献
15.
Chen Bao-ming Zhang Li-qiangDepartment of Air-conditioning Refrigeration Engineering Shandong Institute of Architecture andEngineering Jinan China e-mail:chenbm @ sdai.edu.cnWang Bu-xuanDepartment of Thermal Engineering Tsinghua University Beijing China 《水动力学研究与进展(B辑)》2003,15(6)
The influences of Soret effect and Dufour effect on the natural convection and heat and mass transfer for a porous enclosure were investigated by means of the penalty finite element method. Numerical results indicate that the Soret and Dufour effects have significant influences on heat and mass transfer in the presence of large temperature gradient and concentration gradient. 相似文献
16.
Jianxin Wang Minxian Yang 《Journal of International Financial Markets, Institutions & Money》2009,19(4):597-615
We examine the presence or absence of asymmetric volatility in the exchange rates of Australian dollar (AUD), Euro (EUR), British pound (GBP) and Japanese yen (JPY), all against US dollar. Our investigation is based on a variant of the heterogeneous autoregressive realized volatility model, using daily realized variance and return series from 1996 to 2004. We find that a depreciation against USD leads to significantly greater volatility than an appreciation for AUD and GBP, whereas the opposite is true for JPY. Relative to volatility on days following a positive one-standard-deviation return, volatility on days following a negative one-standard-deviation return is higher by 6.6% for AUD, 6.1% for GBP, and 21.2% for JPY. The realized volatility of EUR appears to be symmetric. These results are robust to the removal of jump component from realized volatility and the sub-samplings defined by structural-changes. The asymmetry in AUD, GBP and JPY appears to be embedded in the continuous component of realized volatility rather than the jump component. 相似文献
17.
基于引力模型的中美农产品贸易边境效应研究 总被引:1,自引:0,他引:1
针对中美两国在农产品贸易上的新变化,应用引力模型的派生模型——边境效应引力模型对中美两国农产品贸易的流量和流向进行理论和实证研究。首先介绍了边境效应引力模型基本模型的推导过程,并引入了调整模型。然后采用1987至2005年其中5年的截面数据进行计算,结果发现:中美农产品贸易的边境效应显著存在,且呈逐年下降趋势;两国之间的农产品贸易边境效应存在流向和区域上的差异;距离的平方并不影响模型的可靠性。 相似文献
18.
黄长征 《山西财经大学学报》2003,25(5):6-8
本文对行为经济学的一个重要微观模型———钱包赌戏悖论建立了认知分析框架 ,不仅彻底消解了该悖论 ,还发现了与效用和概率均无关的一种新的非理性效应。这一效应既可能导致无帕累托效率的交易陷阱 ,也可能与效用歧化和概率误判等已知的行为经济学效应协同作用 ,产生更复杂的非理性决策。 相似文献
19.
This paper employed eleven data series which consist of stocks, bonds, bills, equity premiums, term premiums, and various default premiums to investigate whether January seasonality reported in existing literature is robust across different states of the economy as this has important trading implications. For the periods 1926–1990, small stocks, small stock premiums, low grade bonds, and default premiums (spread between high grade, low grade and government bonds) reveal January seasonality and that the seasonality is robust across different states of the economy except for low grade bond returns and default premiums. January seasonality for low grade bond returns and low grade bond default premiums are primarily driven by results found during periods of economic expansion. Overall, January seasonality is more evident during the economic expansion periods although the magnitude of default premiums is larger during periods of economic contraction. Furthermore, prior findings of strong summer equity returns are primarily driven by the results found during the periods of economic contraction. It is also found that equity returns are generally higher during periods of economic expansion. 相似文献
20.
Alexander Gatch Dimitry Gorsky Zy Biesinger Eric Bruestle Kelley Lee Curt Karboski Meredith L. Bartron Tyler Wagner 《Journal of Great Lakes research》2021,47(2):486-493
Restoration of a wild-produced lake trout Salvelinus namaycush population in Lake Ontario has not been successful despite the adult population often meeting or exceeding restoration targets. Lack of high-quality spawning habitat in Lake Ontario is suggested as one impediment to recruitment of wild lake trout, although the quantity and location of spawning habitat is poorly understood. If high-quality spawning habitat is limited in Lake Ontario, lake trout may be using uncommon spawning locations such as rivers. Anecdotal angler accounts point to the Niagara River as a lake trout spawning location. To better understand the potential of the Niagara River as a spawning location, egg and juvenile fish collections were conducted 12–14 river kilometers from the mouth of the Niagara River from 2010 to 2012; and mature female lake trout with surgically implanted acoustic tags were monitored from 2015 to 2019. Genetic analyses confirmed 60% of collected eggs and 93% of collected post-hatch juvenile fish in the Niagara River were lake trout. Tagged female lake trout returned to the Niagara River over consecutive years during the spawning season. The short duration of lake trout presence in the river (mean = 56 days/year) suggests female lake trout use the Niagara River primarily for spawning. Diversity in spawning locations may provide lake trout population’s resilience against environmental variability through a portfolio effect. Improved identification of riverine spawning locations, including their overall contribution to wild recruitment, may be a useful tool for managers to restore a wild-produced population of lake trout in Lake Ontario. 相似文献