筛管冲蚀磨损研究综述及预防措施

冲蚀磨损是导致油气井防砂完井中筛管失效的重要原因。为了防止或减小筛管冲蚀磨损对油气井生产造成的危害,许多研究者针对筛管冲蚀磨损开展了大量研究工作。结合这方面的研究工作,比较全面地阐述了筛管冲蚀磨损原因、影响因素、实验方法、预测模型,以及防冲蚀筛管方面的内容,并且总结了预防筛管冲蚀磨损的措施。     

改进的沾滴法测量缓蚀剂预膜厚度

分析了传统沾滴法测量预膜厚度存在的问题,对原有的方法进行了改进,使用自制实验装置采用改进后的沾滴评价法测试分析了不同材质、不同管径管件的平均预膜厚度。结果表明,不同材质的管材表面吸附能力不同,导致管件平均预膜厚度相差较大,其中铜管的平均预膜厚度最大(0.05mm左右),碳钢管的平均预膜厚度最小(0.013mm左右);而管径对管件平均预膜厚度的影响很小。实验所得结果与同位素示踪法测定膜厚结果较吻合,从而说明改进后的沾滴评价法是一种室内评价管件平均预膜厚度的有效方法。     

我国天然气产业发展面临的不确定性因素

随着世界石油市场格局发生深刻变化,油价下行,国内GDP增速放缓,我国天然气市场发展的内外部条件正在发生变化。国内天然气生产能力、消费需求以及价格改革等因素存在不确定性,实现《能源发展战略行动计划(2014-2020年)》发展目标面临较大挑战。我国天然气行业已经具备一定的发展基础,但在产业政策导向、税收和价格调控、监管体系建设以及对技术创新的激励和支持等方面仍存在诸多问题。     

垂直院落——当代高层建筑对传统建筑的传承与发展

本人通过对于国内带有"垂直院落"的"实验性"居住、办公的高层建筑对人的行为心理产生影响进行研究,并根据人对不同环境的体验探讨传统院落空间与现代居住、工作空间相联系的本质形态,在当下高层建筑与传统院落这两种模式中找到一个结合点,将"垂直院落空间"与当代高层建筑结合。     

Updating Input–Output Tables with Benchmark Table Series

Numerous methods have been proposed to update input–output (I–O) tables. They rely on the assumption that the economic structure will not change significantly during the interpolation period. However, this assumption may not always hold, particularly for countries experiencing rapid development. This study attempts to combine forecasting with a matrix transformation technique (MTT) to provide a new perspective on updating I–O tables. Under the assumption that changes in the trend of an economic structure are statistically significant, the method extrapolates I–O tables by combining time series models with an MTT and proceeds with only the total value added during the target years. A simulation study and empirical analysis are conducted to compare the forecasting performance of the MTT to the Generalized RAS (GRAS) and Kuroda methods. The results show that the comprehensive performance of the MTT is better than the performance of the GRAS and Kuroda methods, as measured by the Standardized Total Percentage Error, Theil's U and Mean Absolute Percentage Error indices.     

创业失败经验对连续创业意愿的影响——创业失败学习与市场动荡性的作用

基于经验学习理论，探究创业失败经验如何通过创业失败学习影响创业者连续创业意愿，以及市场动荡性的调节作用。对176位有失败经历的创业者进行问卷调查，结果表明：创业失败经验对创业失败学习和连续创业意愿均有显著正向影响；创业失败学习在创业失败经验与连续创业意愿关系间起中介作用；市场动荡性负向调节创业失败学习与连续创业意愿的关系，即市场动荡性越高，创业失败学习与连续创业意愿间的关系越弱。研究结论对于拓展创业失败经验与连续创业意愿研究、帮助创业者从失败中复原，以及激励连续创业具有重要理论价值和实践意义。     

新冠疫情全球蔓延对我国就业的影响及机制分析

新冠疫情全球蔓延对需求端与供给端都造成巨大的冲击,评估此次疫情对我国就业的影响及机制分析变得重要.基于统计比较和使用DID模型,我们研究表明:(1)新冠疫情爆发前,我国总体失业率基本稳定,地区间失业差异趋于缩小;2020年疫情爆发后,我国城镇调查失业率出现明显上升,但其影响在下半年趋于缓解.(2)新冠疫情全球蔓延对我国就业市场产生显著不利的冲击,但对我国31个大城市就业的不利冲击要相对小于总体城镇.新冠疫情导致我国城镇调查失业率总体上升0.31个百分点,导致全国31个大城市调查失业率总体上升0.218个百分点.新冠疫情爆发4个月后我国就业受到的不利影响开始减小.(3)新冠疫情对我国制造业和服务业的经济活动均造成不利冲击,进而对我国就业造成显著不利的影响,且对我国服务业经济活动产生的不利冲击更大.据此,需要严格防控国内疫情反弹,提升一流的营商环境,对受疫情不利影响的企业和劳动者提供优惠政策支持,出台人力资本政策支持建立国家高端人力资本储备池,拓展数字贸易、数字平台等就业创业.     

The State as Both Regulator and Player: The Politics of Transfer of Development Rights in China

The conventional argument that the introduction of transfer of development rights (TDR) shifts the power of land use regulation from the state to the market is increasingly under challenge. In China, the state's grip on land is reinforced through TDR, in which the state is both regulator and player. This state-dominated form of TDR affects China in three ways. First, competing aspirations of different scales of government complicate how TDR is implemented. Although the central state promotes TDR to maintain a national balance of arable land, some local states instrumentalize it to expand their landed basis of accumulation. Secondly, TDR tends to benefit the state but not its people. It may increase the fiscal income of the sending government and lessen the land shortage of the receiving government, but sometimes at the expense of the interests of land users without land ownership. Thirdly, given the state's deep involvement in TDR programs, the key for China's TDR to protect arable land lies not so much in clear property rights or a fully fledged market as in effective checks and balances regarding the state's powers over TDR. These three observations attest to the embeddedness of TDR in the local political economy.     

Long‐term economic consequences of corporate environmental responsibility: Evidence from heavily polluting listed companies in China

In this study, we aim to investigate the long‐term economic consequences of corporate environmental responsibility (CER) by companies from the perspective of earnings persistence and investors' response. Based on firm‐level data of 1,010 heavily polluting listed companies in China, the empirical results are as follows. First, the CER of China's heavily polluting listed companies has significantly improved their earnings persistence, that is, earnings quality. Second, the positive long‐term economic effect of CER has been achieved through two paths: improving companies' operational efficiency and reducing their credit costs. Third, CER increases investors' response to heavily polluting companies' accounting earnings. Moreover, state‐owned listed companies achieve more significant positive long‐term economic effects from CER than others. The results suggest that heavily polluting companies should correctly identify the long‐term value of CER rather than pay excessive attention to the impact of CER on their current costs and benefits.     

A Moral Cleansing Process: How and When Does Unethical Pro-organizational Behavior Increase Prohibitive and Promotive Voice

Journal of Business Ethics - In this study, we draw on moral cleansing theory to investigate the consequence of unethical pro-organizational behavior (UPB) from the perspective of the actors....