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991.
董丽娟 《科技和产业》2020,20(9):219-224
城市道路下穿铁路框架桥顶进施工的关键是合理控制桥梁主体结构的受力。为了对框架桥顶进施工过程进行受力特性分析,采用Midas有限元软件模拟了框架桥在滑板上开始顶进、框架桥重心即将离开滑板、框架桥顶进即将就位三个施工阶段。结果表明,该框架桥的施工过程是安全可靠的,同时结合工程项目实际给出了顶进施工的注意事项。该方法可用来指导类似工程顶进施工过程的受力分析和施工控制。  相似文献   
992.
Using China as the research setting, this paper investigates the relationship between economic policy uncertainty and corporate precautionary cash holdings. Empirical results show a U-shaped relation between economic policy uncertainty and corporate precautionary cash holdings. Empirical analysis, in terms of ownership structure, firm size, corporate competitiveness and geographical location, further shows that (i) the effects for economic policy uncertainty in both state-owned and non-state-owned enterprises are significant, but the effect is stronger for state-owned enterprises; (ii) such significant effect is also found more strongly in small and medium-sized enterprises and highly competitive enterprises; and (iii) the effects for eastern, central and western China are all statistically significant, but the effect is strongest for eastern China.  相似文献   
993.
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   
994.
Nonhub airports are an essential component in the National Plan of Integrated Airport Systems (NPIAS) of the United States in that they connect regional towns and small communities to the air transportation network. Understanding the interplay of operational and spatial factors in determining average passenger yield of nonhub airports provides airlines with valuable information for network planning and revenue management. This study examines factors contributing to the yield variation among nonhub airports in the U.S. Using ordinary least squares (OLS) based econometric models, this study captures the spatial dependence of passenger yield of nonhub airports, which tends to increase with a corresponding increase in distance to the nearest large hub airport. Nonhub airports surrounding large hub airports with higher passenger enplanements and higher average yields also have higher yields than other nonhub airports. In addition, this study finds the effect of Allegiant Airlines in lowering the average passenger yield of the nonhub airports served directly by the airline, which can be termed as ‘Allegiant Effect’. Findings of this study could provide valuable guidance for airlines to analyze network planning strategies and to identify future markets for growth and for policymakers when allocating resources to communities relying on these nonhub airports.  相似文献   
995.
Most empirical studies examining the impact of foreign direct investment (FDI) on economic development use aggregate monetary-based measures such as GDP or TFP growth as indicators for development. We deviate from this approach and use instead the recently developed economic complexity index; this measure summarises the complexity of the productive structure of an economy, and its values can be interpreted as the number of capabilities present in a country. These capabilities are units of productive knowledge necessary for the production of goods, and goods differ in the number of necessary capabilities. Furthermore, we use sectoral FDI data to take differences between sectors of an economy into account, since the number of necessary capabilities also varies between the sectors. In our empirical analysis, covering 63 developing and developed countries over the period 2005–14, we find that FDI in the tertiary sector has a statistically significant and robust positive effect on the number of capabilities, whereas FDI in the primary and secondary sectors generally does not increase the capability set of an economy.  相似文献   
996.
How and under what circumstances can adjusting the inflation target serve as a stabilization-policy tool and contribute to welfare improvement? We answer these questions quantitatively with a standard New Keynesian model that includes cost-push-type shocks. Our proposed inflation target rule calls for the target to be adjusted in a persistent manner and in the opposite direction to the realization of a cost-push shock, which is essentially a makeup strategy. The inflation target rule, combined with a Taylor-type rule, significantly reduces inflation fluctuations originating from cost-push shocks and mitigates the stabilization trade-off, resulting in a similar level of welfare to that associated with the Ramsey optimal policy.  相似文献   
997.
通过单因素及正交实验,比较高产米曲霉在摇床培养与发酵罐培养中生产曲酸的发酵工艺参数。结果表明,在温度为23℃、发酵天数为9 d、接种量为25%、菌龄为96 h时,摇床发酵的曲酸产量达到最高,最高可达98.6 g·L-1;而发酵罐培养的最佳工艺条件是温度23℃、发酵天数4 d,接种量15%,菌龄96 h时,此条件下曲酸产量可达到99.6 g·L-1。本研究为工业化生产曲酸提了供理论依据。  相似文献   
998.
Online complaints have become increasingly influential on the purchasing behavior of customers in recent years. In an effort analyze large quantities of textual complaints and detail the various aspects of them, Aspect-Based Sentiment Analysis was looked to as an ideal framework to take on the task. This study set out to synthesize specific service failure items and categorize them into the groupings related to the hotel guest cycle and the corresponding operations, then compare the patterns of expression used by Asian and Non-Asian guests as the related their hotel experiences. A total of 390,236 online complaint terms posted about 353 hotels in the UK by hotel guests from 63 nations were manually derived from TripAdvisor for analysis. With consideration given to the homophily theory, we posited that Asian and non-Asian guests would exhibit similarities and differences with respect to the service failures they encountered when presented with various items of service. The results confirmed this as Asian guests were shown to encounter more service failures with respect to the engineering segment of operations (e.g. hotel room equipment issues), while non-Asian guests encountered more service failures on the housekeeping end of operations (e.g. toilets, public areas, cleanliness, and bedding). By organizing the failures according the four stages of the guest cycle, it was observed that approximately 80% of the service failures occurred during the occupancy period. This study contributes to the existing literature on hotel guest satisfaction both with respect to the methodology it uses and the new findings it presents on differences in perceptions of service failures members among different cultures.  相似文献   
999.
在旅游业高质量快速发展的背景下,全面厘清与掌握省域尺度范围各旅游节点在网络中的角色和地位,并解析其网络结构效应具有重大意义。针对现有研究因旅游流数据采集限制而较少对团队游空间结构研究的不足,基于云南省旅游包车客运信息,运用社会网络结合空间分析的方法,提取了云南省团队游网络空间结构特征,并对其聚散效应进行分析。结果表明:云南省团队游整体网络密度较小且淡旺季表现出相似特征,网络对各节点的旅游联系与合作影响尚未显现,暴露出云南省团队游旅游市场发展的不均衡;团队游网络外向中心势显著高于内向中心势,网络空间集聚趋势明显;通常具有较强外向中心性的旅游节点同时也具有较强内向中心性,表现出“集中—发散”的聚散规律;旅游节点的聚散效应表现为单个节点以圈层状向外递减形式发生,其扩散路径主要集中于文山—蒙自、景洪—思茅方向。整体上,云南省区域旅游业发展差异明显,应重点加强滇西南与滇西旅游区、滇中与滇东北旅游区的旅游资源开发与合作。  相似文献   
1000.
We extend the Frankel–Wei approach by using wavelet analysis to evaluate the relative importance of the dollar and the renminbi as anchor currencies at different time scales. We find that Asian currencies’ co-movement with the dollar weakened after the global financial crisis, while that with the renminbi strengthened particularly after China introduced a new exchange rate management system in 2015. The evidence suggests that emerging Asian economies have recently attached more importance to the renminbi as an anchor in exchange rate management.  相似文献   
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