TENORM Regulation in the United States of America post-West Virginia vs.EPA Spenser Lynn,Charles Wilson,Emily Caffrey1(1.University of Alabama at Birmingham,School of Health Professions,Clinical and Diagnostic Science...TENORM Regulation in the United States of America post-West Virginia vs.EPA Spenser Lynn,Charles Wilson,Emily Caffrey1(1.University of Alabama at Birmingham,School of Health Professions,Clinical and Diagnostic Sciences,Health Physics Program,1720 University Blvd,Birmingham,AL 35294)Abstract:The regulation of technologically enhanced naturally occurring radioactive materials(TENORM)in the United States of America consists of fragmentary rules split between the federal and state governments.展开更多
In this paper,large deviations principle(LDP)and moderate deviations principle(MDP)of record numbers in random walks are studied under certain conditions.The results show that the rate functions of LDP and MDP are dif...In this paper,large deviations principle(LDP)and moderate deviations principle(MDP)of record numbers in random walks are studied under certain conditions.The results show that the rate functions of LDP and MDP are different from those of weak record numbers,which are interesting complements of the conclusions by Li and Yao[1].展开更多
To investigate the problem of ethylene jet mixing and combustion in the scramjet at high Mach number(Ma = 8), numerical simulations were carried out for different equivalent ratios at cold and combustion conditions, i...To investigate the problem of ethylene jet mixing and combustion in the scramjet at high Mach number(Ma = 8), numerical simulations were carried out for different equivalent ratios at cold and combustion conditions, in which three-dimensional steady compressible RANS and k-ω SST turbulence model were adopted. It demonstrates that as the equivalence ratio increases from 0.42 to 1.08, the combustion becomes more intensified, and the higher backpressure pushes flame to propagate upstream. The supersonic combustion region in the combustor decreases from 92% to 85% with the increase of equivalence ratio from 0.42 to 1.08, resulting in the transition of the combustor from scram-mode to dual-mode. Both mixing and combustion efficiencies decrease by 35% and 16% respectively when the equivalence ratio increases from 0.42 to 1.08, indicating that the high equivalence ratio is unfavorable to the mixing and combustion processes. Combustion mode analysis reveals that the flame in the cavity under the high Mach number is dominated by non-premixed flames, i.e., more than 95% behaves as non-premixed mode, and the heat release is also mainly contributed by non-premixed flame. Increasing the equivalence ratio is beneficial to the thrust performance. Although the viscous force hardly changes with equivalence ratio, the percentage of pressure force used to balance the viscous force increases gradually,which limits the engine performance.展开更多
A new dimensionless number is proposed for dynamic plastic deformation analysis of clamped circular plates under underwater explosion loads by introducing dimensional analysis method to the basic dynamical governing e...A new dimensionless number is proposed for dynamic plastic deformation analysis of clamped circular plates under underwater explosion loads by introducing dimensional analysis method to the basic dynamical governing equations of circular plates.The relation between dimensionless final plastic deformation of circular plates and the new dimensionless number is established based on massive underwater explosion test data.Meanwhile,comparative analysis was discussed with two other published dimensionless parameters which indicated the new dimensionless number proposed in this paper is more effective and extensive to predict the dynamic plastic response of circular plates under underwater explosion condition.展开更多
目的:探究多学科诊疗模式(multidisciplinary team,MDT)在慢性难愈合创面诊疗中的应用成效,为优化此类疾病的临床诊疗提供新思路。方法:回顾性分析2015年1月至2023年10月在北京大学第三医院接受手术治疗的慢性难愈合创面患者的临床资料...目的:探究多学科诊疗模式(multidisciplinary team,MDT)在慢性难愈合创面诊疗中的应用成效,为优化此类疾病的临床诊疗提供新思路。方法:回顾性分析2015年1月至2023年10月在北京大学第三医院接受手术治疗的慢性难愈合创面患者的临床资料,共纳入患者456例,包括男性290例,女性166例,平均年龄(49.4±16.9)岁。根据是否进行术前MDT讨论,将患者分为MDT讨论组和非MDT讨论组。MDT总体执行流程包括:启动与医务处备案、收集资料与初次MDT讨论、告知患者诊疗方案并严格执行、病情变化需再次MDT讨论。比较两组患者的一般临床资料、麻醉风险分级、合并症(高血压、糖尿病、冠心病)、慢性难愈合创面的发生病因与部位等资料的差异。治疗效果的主要观察与结局指标包括入院后达到创面愈合所需的手术次数、创面愈合后的复发率、围手术期并发症(肺部感染、严重心血管事件、静脉血栓栓塞症、脑卒中及谵妄等)的发生率、患者满意度评分等。结果:MDT讨论组患者189例,非MDT讨论组患者267例,两组患者的年龄、性别、体重指数、美国麻醉医师协会(American Society of Anesthesiologists,ASA)分级、合并症、慢性难愈合创面的病因与部位等临床资料差异无统计学意义(P>0.05)。MDT讨论组与非MDT讨论组患者获得创面愈合所需的平均手术次数分别为(2.1±1.1)次与(2.8±1.6)次,差异有统计学意义(P<0.001),这种差异在糖尿病溃疡、外伤或手术后感染、放疗后不愈合等3个病因造成的慢性难愈合创面中也有统计学意义(P<0.05)。非MDT讨论组患者在创面痊愈后的复发率是18.0%,稍高于MDT讨论组的14.3%,但差异无统计学意义(P>0.05)。在围手术期并发症方面,非MDT讨论组的发生率也较MDT讨论组高(3.7%vs.2.6%),但差异无统计学意义(P>0.05)。患者满意度方面,MDT讨论组的评分显著高于非MDT讨论组,差异有统计学意义(96.5 vs.91.1,P=0.028)。结论:多学科诊疗模式能够显著减少慢性难愈合创面患者的住院手术次数,提升治愈效率,提高患者满意度,是优化慢性难愈合创面临床诊疗成效的推荐模式。展开更多
消费者体验需求的提升促使零售商不断探索新渠道模式,以提高原有实体店效益的同时优化线上经营策略。本文分别考虑传统BORO(buy online and return online)和开通BOPS(buy online and pickup in store)两种渠道情形,构建零售商针对消费...消费者体验需求的提升促使零售商不断探索新渠道模式,以提高原有实体店效益的同时优化线上经营策略。本文分别考虑传统BORO(buy online and return online)和开通BOPS(buy online and pickup in store)两种渠道情形,构建零售商针对消费者线上购买并在线上或线下退款的差异化退货策略利润模型,分析两种渠道情形下的最优定价和最优退货策略,进而考虑BOPS渠道的溢出效应,分析零售商在相同退货策略下是否应该开通BOPS渠道。结果表明:(1)在两种情形下,随着线下商店数量的增多,零售商均会倾向于在低开店成本下选择全额退款策略,倾向于在高开店成本下选择部分退款策略;(2)在同渠道情形下,全额退款策略的定价始终低于部分退款策略。在同退货策略下,BOPS情形下的定价始终低于BORO情形;(3)高溢出效应和多商店数量都促使零售商选择开通BOPS渠道,但商店数量决定了BOPS线下麻烦成本规模因子对零售商开通BOPS渠道起推动还是抑制作用。本文为既定商店数量下多渠道零售商退货策略与渠道选择提供了决策支持。展开更多
文摘TENORM Regulation in the United States of America post-West Virginia vs.EPA Spenser Lynn,Charles Wilson,Emily Caffrey1(1.University of Alabama at Birmingham,School of Health Professions,Clinical and Diagnostic Sciences,Health Physics Program,1720 University Blvd,Birmingham,AL 35294)Abstract:The regulation of technologically enhanced naturally occurring radioactive materials(TENORM)in the United States of America consists of fragmentary rules split between the federal and state governments.
基金supported by the National Natural Science Foundation of China(Grant No.11671145)the Science and Technology Commission of Shanghai Municipality(Grant No.18dz2271000).
文摘In this paper,large deviations principle(LDP)and moderate deviations principle(MDP)of record numbers in random walks are studied under certain conditions.The results show that the rate functions of LDP and MDP are different from those of weak record numbers,which are interesting complements of the conclusions by Li and Yao[1].
文摘To investigate the problem of ethylene jet mixing and combustion in the scramjet at high Mach number(Ma = 8), numerical simulations were carried out for different equivalent ratios at cold and combustion conditions, in which three-dimensional steady compressible RANS and k-ω SST turbulence model were adopted. It demonstrates that as the equivalence ratio increases from 0.42 to 1.08, the combustion becomes more intensified, and the higher backpressure pushes flame to propagate upstream. The supersonic combustion region in the combustor decreases from 92% to 85% with the increase of equivalence ratio from 0.42 to 1.08, resulting in the transition of the combustor from scram-mode to dual-mode. Both mixing and combustion efficiencies decrease by 35% and 16% respectively when the equivalence ratio increases from 0.42 to 1.08, indicating that the high equivalence ratio is unfavorable to the mixing and combustion processes. Combustion mode analysis reveals that the flame in the cavity under the high Mach number is dominated by non-premixed flames, i.e., more than 95% behaves as non-premixed mode, and the heat release is also mainly contributed by non-premixed flame. Increasing the equivalence ratio is beneficial to the thrust performance. Although the viscous force hardly changes with equivalence ratio, the percentage of pressure force used to balance the viscous force increases gradually,which limits the engine performance.
基金supported by the National Natural Science Foundation of China(12402444)。
文摘A new dimensionless number is proposed for dynamic plastic deformation analysis of clamped circular plates under underwater explosion loads by introducing dimensional analysis method to the basic dynamical governing equations of circular plates.The relation between dimensionless final plastic deformation of circular plates and the new dimensionless number is established based on massive underwater explosion test data.Meanwhile,comparative analysis was discussed with two other published dimensionless parameters which indicated the new dimensionless number proposed in this paper is more effective and extensive to predict the dynamic plastic response of circular plates under underwater explosion condition.
文摘目的:探究多学科诊疗模式(multidisciplinary team,MDT)在慢性难愈合创面诊疗中的应用成效,为优化此类疾病的临床诊疗提供新思路。方法:回顾性分析2015年1月至2023年10月在北京大学第三医院接受手术治疗的慢性难愈合创面患者的临床资料,共纳入患者456例,包括男性290例,女性166例,平均年龄(49.4±16.9)岁。根据是否进行术前MDT讨论,将患者分为MDT讨论组和非MDT讨论组。MDT总体执行流程包括:启动与医务处备案、收集资料与初次MDT讨论、告知患者诊疗方案并严格执行、病情变化需再次MDT讨论。比较两组患者的一般临床资料、麻醉风险分级、合并症(高血压、糖尿病、冠心病)、慢性难愈合创面的发生病因与部位等资料的差异。治疗效果的主要观察与结局指标包括入院后达到创面愈合所需的手术次数、创面愈合后的复发率、围手术期并发症(肺部感染、严重心血管事件、静脉血栓栓塞症、脑卒中及谵妄等)的发生率、患者满意度评分等。结果:MDT讨论组患者189例,非MDT讨论组患者267例,两组患者的年龄、性别、体重指数、美国麻醉医师协会(American Society of Anesthesiologists,ASA)分级、合并症、慢性难愈合创面的病因与部位等临床资料差异无统计学意义(P>0.05)。MDT讨论组与非MDT讨论组患者获得创面愈合所需的平均手术次数分别为(2.1±1.1)次与(2.8±1.6)次,差异有统计学意义(P<0.001),这种差异在糖尿病溃疡、外伤或手术后感染、放疗后不愈合等3个病因造成的慢性难愈合创面中也有统计学意义(P<0.05)。非MDT讨论组患者在创面痊愈后的复发率是18.0%,稍高于MDT讨论组的14.3%,但差异无统计学意义(P>0.05)。在围手术期并发症方面,非MDT讨论组的发生率也较MDT讨论组高(3.7%vs.2.6%),但差异无统计学意义(P>0.05)。患者满意度方面,MDT讨论组的评分显著高于非MDT讨论组,差异有统计学意义(96.5 vs.91.1,P=0.028)。结论:多学科诊疗模式能够显著减少慢性难愈合创面患者的住院手术次数,提升治愈效率,提高患者满意度,是优化慢性难愈合创面临床诊疗成效的推荐模式。
文摘消费者体验需求的提升促使零售商不断探索新渠道模式,以提高原有实体店效益的同时优化线上经营策略。本文分别考虑传统BORO(buy online and return online)和开通BOPS(buy online and pickup in store)两种渠道情形,构建零售商针对消费者线上购买并在线上或线下退款的差异化退货策略利润模型,分析两种渠道情形下的最优定价和最优退货策略,进而考虑BOPS渠道的溢出效应,分析零售商在相同退货策略下是否应该开通BOPS渠道。结果表明:(1)在两种情形下,随着线下商店数量的增多,零售商均会倾向于在低开店成本下选择全额退款策略,倾向于在高开店成本下选择部分退款策略;(2)在同渠道情形下,全额退款策略的定价始终低于部分退款策略。在同退货策略下,BOPS情形下的定价始终低于BORO情形;(3)高溢出效应和多商店数量都促使零售商选择开通BOPS渠道,但商店数量决定了BOPS线下麻烦成本规模因子对零售商开通BOPS渠道起推动还是抑制作用。本文为既定商店数量下多渠道零售商退货策略与渠道选择提供了决策支持。
