双弧焊对10Ni3CrMoV钢性能影响的研究

对921A钢进行了热模拟试验,同时对该模拟试样作了50℃冲击功测试,结果表明,试验钢经过双丝焊接热循环后,热影响区各区的低温冲击功普遍低于母材。将冲击功最低试样做光学显微组织分析,结果表明试样的组织由母材的回火索氏体组织转变为贝氏体+粒状贝氏体+少量铁素体;将其冲击断口做电子扫描电镜分析,结果表明整个断口主要为放射区,只有少量纤维区和剪切唇区主要呈解理特征;验证了调整双丝间距和焊速得到合理的热循环是取得优良焊接接头的保证。     

智慧街道 从服务开始

未来的＂智慧街道＂是一个微型的智慧城市,是城市信息化的更高级版本。     

Financial openness and profitability premium: Causal evidence from the Shanghai-Hong Kong Stock Connect

This study explores the impact of capital market openness on the profitability premium by using the Shanghai-Hong Kong Stock Connect (SHKSC) programme as an exogenous shock. The empirical results show that (1) we can basically rule out the mispricing mechanism driving the significant profitability premium in China; (2) following SHKSC, the expected stock returns increase more across less profitable firms, and the less profitable firms have more increases in illiquidity, capital structure and information disclosure quality; and (3) the results are still robust after using propensity score matching analysis, deleting the highly volatile periods and conducting a firm-level test with the triple-differencing design.     

The greening effects of regional innovation symbiosis – Evidence from Chinese listed firms

This paper investigates the regional innovation symbiosis effect on firm green innovation. Chinese A-share listed firms from 2012 to 2018 were the sample and the entropy method was used to construct a regional innovation symbiosis index. We found that innovation symbiosis significantly promoted firm-level green innovation, with regional government environment investment playing an intermediary role. Further tests indicated that the effect was more pronounced when firms were in cities that had green industrial parks and in firms that publicly disclosed more environmental information. State-owned firms were found to be more likely to focus on green innovation in higher innovation symbiosis systems.     

典型场景下换电重卡的技术经济性分析

换电重卡能够解决新能源重卡购置成本高、充电时间长等痛点,对于加快我国货车电动化进程具有重要意义。但是,受制于车辆换电成本高、续驶里程短等因素,换电重卡的推广应用需具备合适的应用场景和一定的政策支持。为研究换电重卡的适用场景与应用范围,本文构建了多个典型场景下换电重卡的技术经济性模型,分析了影响换电重卡使用阶段经济性的主要因素。结果表明,对换电重卡经济性影响最大的因素是电池综合服务费;在中长途运输场景下,载货量对换电重卡经济性的影响同样明显;碳交易制度对换电重卡的经济性影响则较为有限。为推动换电重卡的发展,政策层面应给予换电重卡更多支持,降低换电重卡购置成本与运营成本,同时给予换电重卡更多政策便利条件,促进换电重卡的推广应用。     

舒血宁注射液联合丹参滴丸治疗急性冠脉综合征临床研究

目的探讨舒血宁注射液联合丹参滴丸治疗急性冠脉综合征的临床疗效。方法将我院2011年6月至2013年6月收治住院的60例急性冠脉综合征患者分为两组,对照组采用常规治疗,治疗组在对照组基础上采用舒血宁注射液联合丹参滴丸治疗,比较两组患者的临床疗效。结果治疗组总有效率为93.3%,显著高于对照组(73.3%),P<0.05。结论舒血宁注射液联合丹参滴丸治疗急性冠脉综合征疗效显著,值得在临床推广。     

集群企业成功创新的网络模式及其动态匹配：浙江省的实证考察

本研究应用社会网络分析理论，以浙江省集群企业为考察对象，对成功创新型集群企业的创新网络模式进行了系统分析，发现创新网络对集群企业成功创新的支持作用是情境性的，其中，环境不确定性、企业战略导向、企业吸收能力、企业创新类型是四个重要的情境因素。本文实证归纳了与上述情境因素相匹配的四类创新网络模式，为我国不同集群企业构建高效的创新网络提供了策略选择依据。     

E-commerce and Consumption Inequality in China

Consumption inequality may impede economic development and hinder the achievement of common prosperity. Using three waves of the China Family Panel Studies from 2014 to 2018, this paper investigated the impact of e-commerce on consumption inequality, as measured by the Kakwani index. The results indicate that e-commerce can reduce household consumption inequality. A mechanism analysis shows that e-commerce can narrow household income inequality, increase the purchasing power of low-income households, and promote the consumption of households with limited access to offline markets, thereby reducing the consumption gap. A heterogeneity analysis suggests that the positive role of e-commerce in reducing consumption inequality can be more significant among vulnerable households, such as households with elderly members and less-educated households. E-commerce can have varying impacts on consumption inequality across different subcategories of household expenditure, with the greatest impact seen in entertainment and education expenditure. These findings provide new evidence for the role of e-commerce in reducing consumption inequality in the digital economy, and the implications of this are discussed.     

Analyst Herding and Stock Price Crash Risk: Evidence from China

We examine the proposition that firms with disproportionately more analysts herding in their coverage, as measured by a larger herding index value, have higher crash risk. Our findings are consistent with the main proposition. The results suggest that information production, rather than monitoring, is the primary mechanism behind the positive relation between herding and crash risk. Our conclusion is robust to different measures of crash risk, crash risk windows, herding measures, subsamples, and instrumental estimation. In addition, using post‐earnings announcement drift, we report that analyst herding slows down bad news transmission in the market. Our findings extend the literature by documenting that analyst herding plays a role in enhancing crash risk. Analyst herding has economic consequences on the covered firms. We offer support for the concern in the literature regarding analyst herding and market fluctuations.