基于Lyft脉冲涡流检测系统的带隔热层在用球罐金属损失检测技术

介绍脉冲涡流检测技术的优势和存在的局限,以及Lyft脉冲涡流检测系统Log-Lin比例曲线的优势。将脉冲涡流检测技术应用于带隔热层球罐金属损失率检测中,为降低探头的振动效应,创造性地提出了衬垫减振法,并通过多次现场试验总结出球罐扫查衬垫选择经验表。介绍在用球罐脉冲涡流检测过程,得出了检测结果并对球罐金属损失情况进行评价。将脉冲涡流检测数据与超声波检测数据进行比对,检测结果基本一致,证实脉冲涡流检测技术在球罐金属损失检测上具有一定的可靠性。

Lyft拒绝被通用收购

Uber在美国最大的竞争对手Lyft上周拒绝了来自通用汽车的收购要约,并计划新一轮融资。去年年末完成最新一轮融资后,Lyft估值已经上升至55亿美元。Lyft今年6月传出开放交易信息。知情人士此前称,Lyft聘请了投资银行Qatalyst帮助其探索潜在交易。据了解,这家投资银行以帮助科技公司寻找买家而出名。

Quantifying the Impact of Transportation Network Companies on Urban Congestion in a Medium Sized City

In the recent years,TNCs(transportation network companies)and on-demand ridesharing services have grown rapidly.Given conflicting reports on TNC impacts,a need exists to study mode choice shifts in the presence of TNC services and their effects on urban congestion.Using Birmingham,AL(Alabama)as a case study,this paper showcases the feasibility of modeling TNC services using the MATSim(Multi-Agent Transport Simulation)platform,and evaluating the impact of such services on traffic operations.Data used for the study were gathered from Uber drivers and riders through surveys,as well as the US Census.The results indicate that when 200,400,and 800 TNC vehicles are added to the network,the VKT(vehicle kilometers traveled)increase by 22%,23.6%,and 23.2%,respectively,compared to the baseline scenario(no TNC service).Analysis of hourly average speeds,hourly average travel times,and hourly volumes along study corridors further indicate that TNC services increase traffic congestion,in particular,during the AM/PM peak periods.Moreover,the study shows that the optimal TNC fleet size for the Birmingham region is 400 to 500 active TNC vehicles per day.Such fleet size minimizes idle time and the number of TNC vehicles hovering,which have adverse impacts on TNC drivers,and the environment while ensuring TNC service availability and reasonable waiting times for TNC customers.

Analysis of Transportation Users’ Preferences and Attitudes for Identifying Micro-Level Determinants of Transportation Network Companies’ (TNCs) Growth

Over the last decade, the popularity of Transportation Network Companies (TNCs) as a mode of travel has been increasing at a steady pace. This trend highlights the importance of identifying the determinants that influence transportation users to adopt TNCs as a preferred mode choice and the impacts of such preferences on their travel patterns and transportation network operation. This paper reports on a recent study undertaken in Birmingham, AL aiming at understanding and documenting the factors that influence transportation users to select TNCs (such as Uber/Lyft) for completing typical day trips. In doing so, a travel diary questionnaire survey was developed in accordance with the Institute of Transportation Engineers (ITE) Manual on Transportation Engineering Studies using the Qualtrics Research Core platform. The questionnaire was used to survey over 450 transportation users in the Birmingham Metro area. The survey participants provided detailed trip information for a typical 24-hr day along with demographic data and travel preference information. The survey responses provide high-resolution micro-level indicators of travel preferences and behaviors in a TNC-served area, which is a much-needed type of information for researchers and transportation planning agencies.

Efficacy evaluation of True Lift■,a nonsurgical facial ligament retightening injection technique:Two case reports

BACKGROUND With aging,four major facial retaining ligaments become elongated,leading to facial sagging and wrinkling.Even though synthetic fillers are popular,however,it cannot address the problems of soft tissue descent alone,and injection of these fillers requires knowledge of the injection technique including the selection of injection sites,the amount of filler,and the dosage used per injection site.CASE SUMMARY This report aimed to assess the safety and efficacy of a nonsurgical retightening technique to lift and tighten the true ligaments of the face,to improve age-related skin sagging and wrinkling.We objectively quantified the aesthetic lifting effect of a nonsurgical facial retightening procedure that strategically injected high G’ fillers into the base of the true retaining ligaments of the face in two female patients.Facial images were recorded with a three-dimensional facial imaging system for comparison of the clinical outcome.The primary efficacy outcome was the change in facial anthropometric measurements obtained prior to and after injection.The patients were followed for 6 mo after the procedure.Skin retightening was observed,with an evident lift in the orbital,zygomatic,and mandibular regions,and the lifting effect was still observable at the 6-mo followup.Few mild adverse events,such as mild-to-moderate pain,tenderness,and itching,occurred during the 1 st week after the procedure.No adverse events were reported 1 mo post-procedure.CONCLUSION The results of this study demonstrated that our nonsurgical retightening procedure with strategically placed high G’ fillers achieved quantifiable aesthetic improvements in the orbital,zygomatic,and mandibular regions of two patients.Future research with a larger sample could provide a more in-depth evaluation and validation of the aesthetic improvements observed in this study.

网约车改革实践如何形成渐进学习型政策变迁?——基于政策学习与社会学习的双维度分析

在治理和政策成为理论与现实相连接的两大议题之时,中央和地方治理主体是如何通过与市场、社会保持某种互动性学习而不断推动政策变迁的?根据网约车改革实践提出基于政策学习与社会学习双维度分析的渐进学习型政策变迁。在政策学习维度,网约车改革作为一种调适性合作机制,中央政策制定通过给予地方自主性上的“留白”空间,尊重地方意愿,撬动市场力量,凝聚民众共识,提升了政府决策能力,使得政策学习常态化,但也产生了一定的路径锁定。在社会学习维度,网约车改革作为一种策略性反馈机制,中央政策制定对平台公司既有运营模式进行重塑,地位合法化使得其行为更加规范,民众对市场更有信心,对政策更加认同,社会学习与政策学习并存成为必需。在两个学习效果测量上,基于效率水平和人本价值二维特性,政策学习在央地、央市、央社、地市、地社,社会学习在市央、社央、市地、社地、社市五大学习主体上均表现出不同的学习水平。最后指出,治理依托政策,政策反映治理,未来需要从政府与市场、社会双向互动的学习视角出发,迈向更多的渐进学习型政策变迁解释。