Local Cooling Effect of Rotation and Formation of Thermal Transport Barrier in Tokamaks

A simple model,rotation-inducing local cooling,for the mechanism on the formation of thermal transport barrier and the increase in rotation velocity is presented.It is shown that the sheared rotation can make electron temperature profile T_(e)(r)steepen near the rotation layer and▽T_(e)>0 on some location inside it,in agreement with the experimental observations in tokamaks,such as JT-60U with(poloidal or toroidal)sheared rotation and HL-1M with a biased electrode.Such temperature profile can remarkably improve the energy confinement in tokamaks.

Study of limits to the rotation function in the SA-RC turbulence model

The Rotation and Curvature(RC)correction is an important turbulence model modifi-cation approach,and the Spalart-Allmaras model with the RC correction(SA-RC)has been exten-sively studied and used.As a multiplier of the modelling equation’s production term,the rotation function f_(r1)should have a cautiously designed value range,but its limit varies in different models and flow solvers.Therefore,the need of restriction is discussed theoretically,and the common range of f_(r1)is explored in Burgers vortexes.Afterwards,the SA-RC model with different limits is tested numerically.Negative f_(r1)always appears in the SA-RC model,and the difference between simula-tion results brought by the limits is not negligible.A lower limit of 0 enhances turbulence produc-tion,and therefore the vortex structures are dissipated faster and shrink in size,while an upper limit plays an opposite role.Considering that the lower limit of 0 usually promotes the simulation accu-racy and fixes the numerical defect,whereas the upper limit worsens the predictive performance in most cases,it is recommended to limit f_(r1)non-negative while utilizing the SA-RC model.In addi-tion,the RC-corrected model has a better prediction of the attached flow near curved walls,while the SA-Helicity model largely improves the simulation accuracy of three-dimensional large-scale vortices.The model combining both corrections has the potential to become more adaptive and more accurate.

Effects of shore-normal coastal structure on medium-to long-term embayed shoreline evolution

Based on high-tide shoreline data extracted from 87 Landsat satellite images from 1986 to 2019 as well as using the linear regression rate and performing a Mann-Kendall(M–K)trend test,this study analyzes the linear characteristics and nonlinear behavior of the medium-to long-term shoreline evolution of Jinghai Bay,eastern Guangdong Province.In particular,shoreline rotation caused by a shore-normal coastal structure is emphasized.The results show that the overall shoreline evolution over the past 30 years is characterized by erosion on the southwest beach,with an average erosion rate of 3.1 m/a,and significant accretion on the northeast beach,with an average accretion rate of 5.6 m/a.Results of the M–K trend test indicate that significant shoreline changes occurred in early 2006,which can be attributed to shore-normal engineering.Prior to that engineering construction,the shorelines are slightly eroded,where the average erosion rate is 0.7 m/a.However,after shore-normal engineering is performed,the shoreline is characterized by significant erosion(3.2 m/a)on the southwest beach and significant accretion(8.5 m/a)on the northeast beach,thus indicating that the shore-normal engineering at the updrift headland contributes to clockwise shoreline rotation.Further analysis shows that the clockwise shoreline rotation is promoted not only by longshore sediment transport processes from southwest to northeast,but also by cross-shore sediment transport processes.These findings are crucial for beach erosion risk management,coastal disaster zoning,regional sediment budget assessments,and further observations and predictions of beach morphodynamics.

Diagnosis of the Kinetic Energy of the“21·7”Extreme Torrential Rainfall Event in Henan Province,China

An extreme torrential rain(ETR)event occurred in Henan Province,China,during 18-21 July 2021.Based on hourly rain-gauge observations and ERA5 reanalysis data,the ETR was studied from the perspective of kinetic energy(K),which can be divided into rotational wind(V_(R))kinetic energy(K_(R)),divergent wind kinetic energy(K_(D)),and the kinetic energy of the interaction between the divergent and rotational winds(K_(RD)).According to the hourly precipitation intensity variability,the ETR process was divided into an initial stage,a rapid increase stage,and maintenance stage.Results showed that the intensification and maintenance of ETR were closely related to the upper-level K,and most closely related to the upperlevel K_(R),with a correlation coefficient of up to 0.9.In particular,the peak value of hourly rainfall intensity lagged behind the K_(R) by 8 h.Furthermore,diagnosis showed that K transformation from unresolvable to resolvable scales made the ETR increase slowly.The meridional rotational wind(u_(R))and meridional gradient of the geopotential(φ)jointly determined the conversion of available potential energy(APE)to K_(R) through the barotropic process,which dominated the rapid enhancement of K_(R) and then caused the rapid increase in ETR.The transportation of K by rotational wind consumed K_(R),and basically offset the K_(R) produced by the barotropic process,which basically kept K_(R) stable at a high value,thus maintaining the ETR.

Safety at Work of Participants in the Railway Transport of Dangerous Goods

The transport of dangerous goods always represents a potential risk to life,human health,property,and environmental protection.For this reason and in order to preserve the lives and health of the participants in the transport process,adequate protection measures must be taken before,during,and after the transport of dangerous goods.Since the railway itself is a recipient of dangerous goods that are essential for its own operation,and is also a carrier of large quantities of various dangerous goods,these measures are of paramount importance.This paper examines,from a point of view of the protection of lives and health of the participants in the transport process and the safe transport of dangerous goods,the conditions of shipment and transport of dangerous goods,the obligations of the participants,and the essential ways for their proper handling.Proper application of safety at work prevents impromptu and indolent attitude in transporting dangerous goods,thus contributing to protection of people lives and health.Finally,this paper includes preventive measures and basic principles for implementation of safety at work in the transport of dangerous goods.

Risk Evaluation and Risk Control in Road Overbuilding of Transport Routes for Dangerous Goods

Overbuilding, i.e. capping or decking, of roads assigned for the transportation of dangerous goods in major cities is being considered more often in many countries including Sweden. This type of facility introduces a number of risks and challenges related to rare events, such as dangerous goods accidents in tunnels, with a potential to cause substantial damage, e.g. collapse of buildings on the over site development. Many argue that the major problem associated with risk evaluation of such risks is the lack of commonly agreed acceptance criteria and regulations. Approaching the problem from a scientific perspective suggests that the root cause of this problem has not been adequately identified. However, there are strong indications that it is because the nature of the risk is not adequately addressed in risk analysis. In this study, we have structured the problem and propose ways of making progress in the evaluation of risk exposure and risk control. It is concluded that several challenges are inherent in the risk management of decking over routes for the transport of dangerous goods, and that these must be addressed in order to be able to control the risk. One of the complicating factors is that it is practically and economically impossible to construct the overbuilding so that it can withstand the maximum permissible explosion load. The main conclusions of this study are that overbuilding of dangerous goods routes has the potential to lead to catastrophic events, that the transport of dangerous goods in the future is associated with considerable intrinsic uncertainties, and that the possibility of supervising and controlling the transport of goods is limited once the route is in use.

Vehicle Tracking in the Process of Transport of Dangerous Goods GPS/GSM Technology

In the paper it has reviewed the monitoring of vehicles in the transport of hazardous substances based on the using of GPS/GSM technology. The basic principles of the GPS concept and hardware have been exhibited which are implemented in locating the vehicle. They have also identified the locating techniques underlying the monitoring process. It has presented an active system for monitoring parameters of the means of transport.

A new European standard for the electronic equipment used in the transport of dangerous goods published

The transport of dangerous goods(TDG)is a field where the precision of control,measurement and event data of electronic equipment is crucial.To ensure the necessary level of precision,high-level standards are fundamental.Therefore,new EN 15969-1:2022,Tanks for transport of dangerous goods-Digital interface for the data transfer between tank vehicle and with stationary facilities-Part 1:Protocol specification-Control,measurement and event data,which addresses this need,is a welcome addition to CEN’s portfolio.

Research on the evolutionary game of the supervision of civil aviation dangerous goods transportation training

This study is carried out to promote the precise supervision of dangerous goods transportation training,improve the efficiency of civil aviation supervision and further ensure the safety of air transportation.First,from the perspective of behaviour interaction and interest demands,evolutionary game theory is used to construct a tripartite evolutionary game model of dangerous goods transportation training institutions,the Civil Aviation Administration of China(CAAC)and the public.Then,the evolutionary game equilibrium of the system is further analysed under the joint action of the three parties.Finally,the influences of important parameters of the model on the behavioural strategy selection of the three parties are investigated via MATLAB numerical simulation.The conclusions reveal that the system has three evolutionarily stable strategies under different parameters,namely(non-compliant training,supervision,non-participation in supervision),(non-compliant training,supervision,participation in supervision)and(compliant training,supervision,non-participation in supervision).Moreover,the CAAC supervision cost,the fine amount,the supervision cost of public participation,the supervision success rate and the reporting reward amount are the main parameters that affect the behavioural strategy selection of the tripartite game players.The conclusions and suggestions of this study provide a decision-making basis and guidance for the supervision and management of civil aviation dangerous goods transportation training.

Factors Analysis of Affecting Loading and Reinforcing Scheme of Large Goods in Railway

Large goods transported in railway are kinds of special goods and they are very important in national construction. In order to transport safely, loading and reinforcing schemes must be made first. How to design a reasonable scheme will be affected by many factors. This paper presents the characteristic of the large goods, summarizes the process of designing a loading and reinforcing scheme of large good, then probes the factors of affecting the loading and reinforcing scheme and gives a detail analysis. It’s considered that those out-of-gauge and overweight degree of goods, center-of- gravity height of a loaded wagon, position of center-of-gravity of goods, type of wagon for using, reinforcement material and reinforcement method, transport expense and transport organization could affect a scheme in the aspects of safety, economy, rapidity and convenience. This conclusion will instruct and help to make a good scheme.

Applying Network Flow Optimization Techniques to Improve Relief Goods Transport Strategies under Emergency Situation

Given the seriously damaged emergency situation occurring after a large-scale natural disaster, a critical and important problem that needs to be solved urgently is how to distribute the necessary relief goods, such as drinking water, food, and medicine, to the damaged area and how to transport them corresponding to the actual supply and demand situation as quickly as possible. The existing infrastructure, such as traffic roads, bridges, buildings, and other facilities, may suffer from severe damage. Assuming uncertainty related with each road segment’s availability, we formulate a transshipment network flow optimization problem under various types of uncertain situations. In order to express the uncertainty regarding the availability of each road segment, we apply the Monte Carlo simulation technique to generate random networks following certain probability distribution conditions. Then, we solve the model to obtain an optimal transport strategy for the relief goods. Thus, we try to implement a necessary and desirable response strategy for managing emergency cases caused by, for example, various natural disasters. Our modeling approach was then applied to the actual road network in Sumatra Island in Indonesia in 2009, when a disastrous earthquake occurred to develop effective and efficient public policies for emergency situations.

Correlation between impedance spectroscopy and bubble-induced mass transport in the electrochemical reduction of carbon dioxide

In the electrochemical conversion of carbon dioxide, high currents need to be employed to obtain large production rates, thus implying that mass transport of reactants and products is of crucial importance.This aspect can be investigated by employing a model that depicts the local environment for the reduction reactions. Simultaneously, electrochemical impedance spectroscopy, despite being a versatile technique, has rarely been adopted for studying the mass transport features during the carbon dioxide(CO_(2))electroreduction. In this work, this aspect is deeply analyzed by correlating the results of impedance spectroscopy characterization with those obtained by a bubble-induced mass transport modeling under controlled diffusion conditions on a gold rotating disk electrode. The effects of potential and rotation rate on the local environment are also clarified. In particular, it has been found that CO_(2) depletion occurs at high kinetics when the rotation is absent, giving rise to an increment of the competing hydrogen evolution reaction. This feature reflects in an enlargement of the diffusion resistance, which overcomes the charge transport one.

A tentative study on security management based on dangerous goods road transportation

The paper conducts analysis on the causes of dangerous goods road transportation accidents by applying analytic technique of security system science - Event Tree Analysis （ETA）. By computing minimum cut and minimal path set of event tree and the important level of elementary event, the paper elicits the results that the factors of causing road transportation accident are multiple and its hazard is great while the paper also elicits the sorting of structural important level of elementary event. The paper offers the security countermeasures for dangerous goods road transportation which plays a vital role in safeguarding dangerous goods road transportation security.

国内外危险货物道路运输标准对比分析及启示

危险货物种类繁多,用途广泛。道路与运输过程中一旦发生危险货物运输事故,后果往往非常严重。因此,危险货物道路运输作为安全生产重点领域之一,其高质量发展一直受到高度关注。本文通过深入研究《危险货物国际道路运输公约》、相关国内外标准,对危险货物豁免要求、安保防范要求、包装测试和使用要求,以及常压危险货物可移动罐柜测试和使用要求等进行了对比分析,探讨了相关国际规则和国际标准在我国的适用性。本研究为我国制定强制性国家标准《危险货物道路运输规则》提供了一定的参考依据,有助于促进我国危险货物道路运输安全管理水平的提升。

区块链赋能视角下危险货物道路运输安全监管演化博弈研究

为分析区块链技术在危险货物道路运输安全监管中的应用价值,利用演化博弈法建立由监管方、承运方和托运方构成的三方演化博弈模型,确定收益矩阵和复制动态方程,分析演化博弈系统中各均衡点的稳定条件。利用MATLAB对各利益主体的策略选择进行了动态演化分析,探究三方演化博弈中相关变量对三方演化策略选择的影响。结果表明:区块链的应用成本与各参与方的策略选择呈负相关;应用区块链技术对监管方合规监管、承运方和托运方遵守规定倾向的提升程度及应用区块链时监管方的补贴程度与各方的策略选择呈正相关;监管方责任规避系数与策略选择呈负相关,承运方和托运方的责任附加系数与策略选择呈正相关。

基于演化博弈的民航危险品运输培训监管

为促进民航危险品运输培训精准监管,提升民航监管效能,实现合规培训与监管的最佳局面,进一步保障航空运输安全。首先从行为交互和微观经济学的角度,运用演化博弈方法,构建危险品运输培训机构和民航局双方演化博弈模型,定量分析博弈双方行为策略选择的情境条件及形成原因;然后运用MATLAB软件对重要参数的敏感性进行数值仿真分析,探讨受训者能力不足造成不安全事件概率、查处成功率、处罚力度和监管成本4个重要参数对系统演化路径及结果的影响效应;最后从管理层面对民航危险品运输培训监管提出有针对性的建议及措施。结果表明:受训者能力不足造成不安全事件概率、查处成功率和处罚力度3个参数对博弈双方行为选择具有正效应,而监管成本对博弈双方行为选择具有负效应。

新型尾绳旋转器的检测系统设计

针对传统技术手工目测和手工检测尾绳旋转器的方式,设计了一种新型尾绳旋转器的检测系统,该装置能有效提高检测效率,同时具有预警、报警等功能,降低了人力、物力成本,预防了提升运输事故的发生。

危险货物运输驾驶人风险倾向分类及识别模型研究

为合理评估危险货物运输驾驶人驾驶过程中的风险倾向,建立危险货物运输驾驶人风险倾向聚类及辨识体系,以动态监控系统中记录的驾驶人实时违规预警数据为基础,选取可能引发交通冲突的安全关键事件为特征参数,利用探索性因子分析方法实现指标降维,提取驾驶人风险倾向主因子,并通过K means算法聚类不同风险倾向的驾驶人,最后基于聚类结果监督训练随机森林模型,辨识未知驾驶人的风险倾向。结果表明,利用选取的8类安全关键事件特征参数,可以将驾驶人风险倾向划分为攻击驾驶倾向、鲁莽驾驶倾向、驾驶分神倾向和驾驶疲劳倾向,且可以识别风险较低的驾驶人,基于随机森林模型的驾驶人风险倾向识别准确率为88.68%,可以较好地实现危险货物运输驾驶人风险倾向辨识。研究结果为危险货物运输驾驶人风险倾向分类及识别提供了方法依据。

废旧车用锂电池运输包装箱温度场仿真分析与优化设计

目的研究废旧车用锂电池运输包装箱的热安全性和优化措施。方法以15组1.6kW·h方形锂电池模组为研究对象,按照P911、LP906规范设计运输包装箱,并建立废旧车用锂电池运输包装箱模型,实验验证模型后进行温度场仿真分析,对包装箱集液槽、箱壁壁厚、隔热材料进行优化设计。结果集液槽底部添加阻燃棉可解决温度超过100℃问题,且箱体阻燃棉厚度为15 mm和集液槽底部阻燃棉厚度为40 mm优化效果最佳,改用纳米二氧化硅纤维棉后隔热效果能提高了16.0%。最终实现箱体阻燃棉用料节约了68.75%,集液槽隔热效果提升了41.5%,包装箱整体皆满足P911及LP906要求。结论研究结果可为废旧车用锂电池危险品包装研究提供重要参考。

旋转磁岛对捕获快离子输运影响的研究

采用漂移动理学理论,研究了旋转磁岛与捕获快离子的反弹运动和进动频率(包括极向进动和螺旋进动)之间共振引起的快离子输运。求解捕获离子香蕉轨道回旋心动理学方程,获得了共振和非共振情况下的快离子分布函数。计算了磁漂移、电漂移和磁岛旋转产生的快离子输运通量。与极向角周期性相关的磁漂移和电漂移产生的输运在磁岛分界线附近存在强烈的流剪切,在磁岛靠近等离子体边界一侧输运向内;磁岛旋转诱发的输运则与磁漂移和电漂移产生的输运相反,在磁岛靠近等离子体边界一侧输运沿径向向外,并起主要作用。当磁岛宽度大于某一阈值岛宽时,捕获快离子输运增长缓慢,趋于饱和。