EFFECTS OF INCOMING FLOW ASYMMETRY ON SHOCK TRAIN STRUCTURES IN CONSTANT-AREA ISOLATORS

To simulate the actual flowfield at the exit of the supersonic/hypersonic inlet, a wind tunnel is designed to study the flow in the scramjet isolator under the asymmetric incoming flow. And compression fields in the isolator are investigated using wall static and pitot pressure measurements. Three incoming Mach numbers are considered as 1.5, 1.8 and 2. Results show that the increase of the asymmetry of the flow at the isolator entrance leads to the increase of the shock train length in the isolator for a given pressure ratio. Based on the analysis of the flow asymmetry effect at the isolator entrance on the shock train length, a modified correlation is proposed to calculate the length of the shock train. Predicted results of the proposed correlation are in good agreement with the experimental data.

Flow structure around high-speed train in open air

According to the analysis of the turbulent intensity level around the high-speed train, the maximum turbulent intensity ranges from 0.2 to 0.5 which belongs to high turbulent flow. The flow field distribution law was studied and eight types of flow regions were proposed. They are high pressure with air stagnant region, pressure decreasing with air accelerating region, low pressure with high air flow velocity region I, turbulent region, steady flow region, low pressure with high air flow velocity region II,pressure increasing with air decelerating region and wake region. The analysis of the vortex structure around the train shows that the vortex is mainly induced by structures with complex mutation and large curvature change. The head and rear of train, the underbody structure, the carriage connection section and the wake region are the main vortex generating sources while the train body with even cross-section has rare vortexes. The wake structure development law studied lays foundation for the train drag reduction.

Properties of train traffic flow in a moving block system

The development direction of railways is toward the improvement of capacity and service quality, where the service quality includes safety, schedule, high speed, and comfort. In light of the existing cellular automaton models, in this paper, we develop a model to analyze the mixed running processes of trains with maximal speeds of 500 km/h and 350 km/h respectively in the moving block system. In the proposed model, we establish some sound rules to control the running processes of a train, where the rules include the departure rules in the intermediate stations, the overtaking rules, and the conditions of speed limitation for a train stopping at a station or passing through a station. With the consideration of the mixed ratio and the distance between two adjacent stations, the properties of the train traffic flow （including capacity and average speed） are simulated. The numerical results show that the interactions among different trains will affect the capacity, and a proper increase of the spatial distance between two adjacent stations can enhance the capacity and the average speed under the moving block.

Detached-eddy simulation of flow around high-speed train on a bridge under cross winds

In order to describe an investigation of the flow around high-speed train on a bridge under cross winds using detached-eddy simulation(DES), a 1/8th scale model of a three-car high-speed train and a typical bridge model are employed, Numerical wind tunnel technology based on computational fluid dynamics(CFD) is used, and the CFD models are set as stationary models. The Reynolds number of the flow, based on the inflow velocity and the height of the vehicle, is 1.9×10~6. The computations are conducted under three cases, train on the windward track on the bridge(WWC), train on the leeward track on the bridge(LWC) and train on the flat ground(FGC). Commercial software FLUENT is used and the mesh sensitivity research is carried out by three different grids: coarse, medium and fine. Results show that compared with FGC case, the side force coefficients of the head cars for the WWC and LWC cases increases by 14% and 29%, respectively; the coefficients of middle cars for the WWC and LWC increase by 32% and 10%, respectively; and that of the tail car increases by 45% for the WWC whereas decreases by 2% for the LWC case. The most notable thing is that the side force and the rolling moment of the head car are greater for the LWC, while the side force and the rolling moment of the middle car and the tail car are greater for the WWC. Comparing the velocity profiles at different locations, the flow is significantly influenced by the bridge-train system when the air is close to it. For the three cases(WWC, LWC and FGC), the pressure on the windward side of train is mostly positive while that of the leeward side is negative. The discrepancy of train's aerodynamic force is due to the different surface area of positive pressure and negative pressure zone. Many vortices are born on the leeward edge of the roofs. Theses vortices develop downstream, detach and dissipate into the wake region. The eddies develop irregularly, leading to a noticeably turbulent flow at leeward side of train.

Pressure Distribution Characters of Flow Field around High-Speed Train

Based on incompressible viscous fluid Navier-stokes equation and k-ε 2-equations turbulent model, an investigation on 3D turbulent flow field around four kinds of train models has been made by finite element method. From the calculation, the pressure distribution characters of now field around high-speed trains have been obtained. It is significant for strength design of the high-speed train body, for resisting wind design of the facilities beside the high-speed railways and for determining the aerodynamic force of induced air to the human body near the railways.

Effect of swimming training on neural microcirculation in rats with sciatic nerve compression A study based on laser Doppler flowmetry

Microcirculation of the peripheral nerve is necessary for neural growth and regeneration. However, technical limitations have limited studies in this area. The few studies conducted have concerned active exercise effects on microcirculation of the peripheral nerve. Using an animal experiment, this study evaluated the effect of swimming training on microcirculation of injured peripheral nerve by laser Doppler flowmetry. The results showed that the blood vessel at the distal end of the peripheral nerve was the main blood supply for the nerve, and the internal blood supply for the nerve had strong compensatory ability. Swimming training promoted the functional recovery of rats with sciatic nerve injury and the regeneration of myelin sheath and blood vessels, but had no impact on neural blood flow.

基于GO-FLOW法的某高速列车齿轮箱可靠性分析方法研究

针对传统FTA无法对有反馈、多状态、有时序系统进行可靠性计算的问题,提出了一种基于GO-FLOW法的某型高速列车变速箱的可靠性分析方法。首先,根据齿轮箱的工作原理和结构逻辑,确定了操作符的类型并建立了齿轮箱系统的GO-FLOW图模型。其次,修正共因故障后计算齿轮箱成功概率并绘制齿轮箱的健康变化规律曲线。最后,对比GO-FLOW与FTA的分析结果可知,GO-FLOW法在齿轮箱健康评估应用中高效可行,且具有时序性。同时,该方法减少了计算量,为维修维护高速列车齿轮箱系统和提升其健康管理水平提供了一定的理论指导作用。

超重/肥胖人群的最佳运动方式:来自能量消耗和底物代谢的证据

目的:通过比较超重/肥胖男性青年在高强度间歇训练(high-intensity interval training,HIIT)、单独抗阻训练(resistance training,RT)及血流限制(blood flow restriction,BFR)结合抗阻训练(BFR-RT)运动过程中和恢复期的能量消耗和底物代谢特征,探讨超重/肥胖人群的最佳运动方式。方法:将30名超重/肥胖男性青年随机分配到RT组(n=10)、BFR-RT组(n=10)及HIIT组(n=10)。采用CORTEX心肺功能测试系统(MetaLyzer Ⅱ-R2,德国)测量受试者在运动前、运动中、运动后即刻、运动后1 h及运动后24 h的VO_(2)、VCO_(2)、呼吸气体交换率、能耗速率、糖脂氧化速率、供能速率及百分比,并对各阶段的各指标进行统计分析。结果:能耗速率方面,在运动中,HIIT组显著高于RT组(P<0.05)和BFR-RT组(P<0.01);在运动后即刻,HIIT组显著高于BFR-RT组(P<0.05)。糖氧化及供能速率方面,在运动中,HIIT组显著高于RT组(P<0.05)和BFR-RT组(P<0.01);在运动后即刻,RT组(P<0.05)和HIIT组(P<0.01)均显著高于BFR-RT组;运动后1 h时,BFR-RT组显著高于RT组(P<0.001);在运动后24 h,BFR-RT组(P<0.01)和HIIT组(P<0.05)均显著高于RT组。脂肪氧化及供能速率方面,在运动中,BFR-RT组显著高于RT组(P<0.01);在运动后24 h,RT组显著高于HIIT组(P<0.01)。糖脂氧化供能比方面,在运动中,HIIT组显著高于BFR-RT组(P<0.01);在运动后即刻,HIIT组显著高于RT组(P<0.05)和BFR-RT组(P<0.01);在运动后1 h,BFR-RT组显著高于RT组(P<0.05);在运动后24 h,HIIT组显著高于RT组(P<0.01)。结论:BFR结合低强度RT在运动中的脂代谢效率最高,RT在恢复期的脂代谢提升效益持续时间最长,而HIIT在运动中的脂代谢效率优于RT,且两者在恢复期的能耗速率相似。尽管3种运动方式各有优势,均可作为超重/肥胖人群的减重运动方式,但HIIT时间短,能耗及脂代谢效率相对较高,加之其组合训练形式多样化,优先推荐其作为超重/肥胖人群的减脂运动方式。

血流限制训练法联合抗阻训练对运动者肌肉相关指标影响的Meta分析

目的:通过收集血流限制训练法联合抗阻训练的相关文献,依照系统评价和Meta分析的范式,分析血流限制训练法联合抗阻训练与抗阻训练对运动者肌肉相关指标和专项能力的不同影响,旨在为运动者在训练实践中运用血流限制训练提供数据支持。方法:检索中外数据库(中国知网、万方、PubMed、Web of Science和SPORTDiscus),应用血流限制训练法联合抗阻训练对对象为运动者中大学生运动者肢体围度、肌肉质量、肌肉力量和专项运动能力影响的随机对照试验,检索起止时间为2000-01-01/2023-10-12。至少2名研究者采用Cochrane协作网偏倚风险评估工具和标准对纳入文献进行质量评价。使用RevMan 5.4软件进行异质性检验、数据合并、亚组分析、绘制森林图和敏感性分析,绘制漏斗图并进行发表偏倚评价和敏感性分析。评价指标为肢体围度、肌肉厚度、肌肉力量和专项能力等,对不同专项运动能力进行亚组分析。结果:①共纳入18项随机对照试验,共403例受试者,根据Cochrane协作网偏倚风险评估工具,纳入文献中文献质量为A级的有16篇,B级有2篇。②将血流限制训练法联合抗阻训练与抗阻训练之间的效果进行对比,在肢体围度方面,两组间无显著性差异(SMD=0.03,95%CI:-0.16-0.21,P=0.78);在肌肉厚度方面(SMD=0.14,95%CI:0.01-0.27,P=0.03)及肌肉力量方面(SMD=0.37,95%CI:0.14-0.60,P=0.001)两组间有显著性差异。③对专项能力指标进行亚组分析结果显示,距离指标的分析结果存在高异质性(I2=73%),时间指标的分析结果存在高异质性(I2=55%),分析可能原因是各研究的测试方法及评估指标意义的不同导致;功率指标的分析结果显示无异质性(I2=0%);血流限制训练法联合抗阻训练对距离指标具有显著影响(P<0.01)。④合并效应结果显示,血流限制训练法联合抗阻训练比较抗阻训练对于专项能力的影响(P=0.41),提示不同训练方法对于专项能力不存在显著性影响。结论:①两种训练方法均能够促进大学生运动者的肌肉厚度、肌肉力量和专项能力,血流限制训练法联合抗阻训练相较于抗阻训练在促进运动员肌肉厚度、肌肉力量和部分专项能力方面具有显著性效果。因此,可以在专项训练之中科学合理地融合血流限制训练法,以差异性的生理刺激综合作用于肌肉,以取得更好的训练效果。②然而,由于纳入的研究数量较少,以及其他可能存在的局限性,今后需要纳入更多的高质量、多项目类型和性别的随机对照试验来证实。

低强度抗阻结合血流限制训练12周青年人体成分、肌肉力量及动脉弹性功能

背景:高强度抗阻训练能有效提高肌肉力量,但动脉硬化风险较高;高强度抗阻训练结合有氧运动可有效降低动脉硬化水平;低强度抗阻结合血流限制训练不需要高负荷力量刺激肌肉,或许是提高肌肉力量、保持动脉弹性的科学训练方法。目的:探讨12周的低强度抗阻训练结合血流限制训练对青年人体成分、肌肉力量及动脉弹性功能的影响,为制定个性化训练方案提供理论支撑。方法:随机招募55名大学生并通过抽签的方式随机分为高强度抗阻训练组、高强度抗阻结合有氧运动组及低强度抗阻结合血流限制训练组,分别进行为期12周的高强度抗阻训练、高强度抗阻训练结合有氧运动、低强度抗阻训练结合血流限制训练,训练结束后进行身体成分、肌肉力量及动脉弹性功能测试。结果与结论:12周的训练干预后,高强度抗阻训练组、低强度抗阻结合血流限制训练组的瘦体质量显著增加(P<0.05),3组的最大重复次数(1RM)和膝关节等速肌力均显著增加(P<0.05),高强度抗阻结合有氧运动组、低强度抗阻结合血流限制训练组的动脉弹性功能显著改善(P<0.05)。结果表明:12周的高强度抗阻训练、低强度抗阻训练结合血流限制训练能显著改善身体成分;3种训练方式均能增加肌肉力量;12周的高强度抗阻训练结合有氧运动、低强度抗阻训练结合血流限制训练均能改善动脉弹性功能,且低强度抗阻训练结合血流限制训练的效果优于高强度抗阻训练结合有氧运动。因此,建议将低强度抗阻训练结合血流限制训练作为首选训练方式,以改善动脉弹性,降低动脉硬化的风险。

血流限制训练预防与治疗足踝部损伤

背景:近年来,血流限制训练在踝关节损伤康复治疗中的应用逐渐增多,该技术可提高肌肉力量,尤其是结合低强度抗阻训练时可达到高负荷抗阻训练类似的效果。目的:阐述血流限制训练在预防与康复足踝部损伤中的应用现状。方法:在中国知网、PubMed和Web of Science数据库中进行文献检索,以“血流限制训练,加压训练,足踝,踝关节”为中文检索词,以“blood flow restriction,BFR,KAATSU,ankle,foot”为英文检索词,检索各数据库建库时间至2023年7月的相关文献,根据纳入及排除标准最终纳入50篇文献进行综述。结果与结论:在足踝部的应用中,血流限制训练主要用于对健康人群跟腱厚度和踝部肌力的研究,以及慢性踝关节不稳、跟腱断裂后及外踝骨折后。单次血流限制训练能使健康人群跟腱厚度减小,而长期血流限制训练能使健康人群跟腱厚度增加。血流限制训练能预防健康人群肌力下降,同时低强度血流训练能促进损伤患者踝部肌力的恢复。在目前的研究中很少发现与血流限制相关的不良事件,未来研究应比较不同训练方案在不同人群中的作用疗效,优化研究内容。

低负荷血流限制训练在肌少症中的研究进展

目的旨在探讨低负荷血流限制训练(LL-BFR)在肌少症干预中的研究进展,以期为该疾病的预防和治疗提供理论指导和实践参考。方法通过文献资料法阐述LL-BFR训练的作用机制以及在肌少症中的应用效果,结合现有研究讨论其目前所面临的问题,并对具体实施策略提出建议。结果LL-BFR训练通过激素分泌、蛋白质合成等机制可达到与高强度训练相似的效果,能显著提高老年人的肌肉力量和质量,并在一定程度上改善血管功能。但该方法仍存在安全问题,如血管疾病和肌肉损伤等不良反应,在方案设计中需注意压力和训练参数的优化设置。结论作为一种耐受性良好的新型手段,LL-BFR训练在防治肌少症方面具有很大的潜力,有望成为传统运动的替代方案。但目前其临床应用面临一定的局限性和潜在风险,因此需要在科学指导下进行个性化方案的制定和实施。

Numerical study on wake characteristics of high-speed trains

Intensive turbulence exists in the wakes of high speed trains, and the aerodynamic performance of the trailing car could deteriorate rapidly due to complicated features of the vortices in the wake zone. As a result, the safety and amenity of high speed trains would face a great challenge. This paper considers mainly the mechanism of vortex formation and evolution in the train flow field. A real CRH2 model is studied, with a leading car, a middle car and a trailing car included. Different running speeds and cross wind conditions are considered, and the approaches of un- steady Reynold-averaged Navier-Stokes （URANS） and de- tached eddy simulation （DES） are utilized, respectively. Re- suits reveal that DES has better capability of capturing small eddies compared to URANS. However, for large eddies, the effects of two approaches are almost the same. In conditions without cross winds, two large vortex streets stretch from the train nose and interact strongly with each other in the wake zone. With the reinforcement of the ground, a complicated wake vortex system generates and becomes strengthened as the running speed increases. However, the locations of flow separations on the train surface and the separation mechanism keep unchanged. In conditions with cross winds, three large vortices develop along the leeward side of the train, among which the weakest one has no obvious influence on the wake flow while the other two stretch to the tail of the train and combine with the helical vortices in the train wake. Thus, optimization of the aerodynamic performance of the trailing car should be aiming at reducing the intensity of the wake vortex system.

针刺联合吞咽康复训练治疗脑卒中后吞咽障碍临床研究

目的:研究针刺联合吞咽康复训练治疗脑卒中后吞咽障碍的临床疗效。方法:选择脑卒中后吞咽障碍患者150例,按随机数字表法分为观察组与对照组各75例。两组均接受吞咽康复训练,观察组在此基础上联合针刺治疗,比较两组治疗前后洼田饮水试验评分、视频透视吞咽检查量表(VFSS)评分、功能性经口摄食量表(FOIS)评分、神经功能缺损症状积分,以及左椎动脉、右椎动脉、基底动脉血流速度,比较两组临床疗效及观察组不同时期吞咽障碍患者临床疗效。结果:治疗后两组洼田饮水试验评分较治疗前降低,VFSS评分、FOIS评分较治疗前升高(P<0.05);治疗后观察组洼田饮水试验评分低于对照组,VFSS、FOIS评分高于对照组(P<0.01)。治疗后两组左椎动脉、右椎动脉、基底动脉血流速度均较治疗前升高(P<0.05),且观察组左椎动脉、右椎动脉、基底动脉血流速度均高于对照组(P<0.01)。治疗后两组神经功能缺损症状积分均较治疗前降低(P<0.05),且观察组各神经功能缺损症状积分均低于对照组(P<0.01)。观察组治疗总有效率90.67%,高于对照组的78.67%,两组临床疗效比较,差异有统计学意义(P<0.05),且观察组口腔前期患者的临床疗效优于口腔准备期、口腔期(P<0.05)。结论:针刺联合吞咽康复训练治疗脑卒中后吞咽障碍效果显著,能够改善患者吞咽能力,快速减轻症状,并促进血液循环,尤其是口腔前期患者的疗效更为理想。

自由跤运动员专项训练时的血流限制对其肌肉力量和形态的影响

目的:探讨4周自由跤专项训练时,血流限制对女子自由跤运动员肌肉力量以及身体成分、肢体围度、肌肉厚度的影响。方法:将20名专项训练经历在5年以上的北京队一线女子自由跤运动员随机分为加压组和对照组。两组受试者使用相同的专项训练内容,加压组训练时在上肢或下肢佩戴加压带进行血流限制。比较两组受试者4周训练前后肌肉力量以及身体成分、肢体围度和肌肉厚度的变化。结果:4周训练后,1)与训练前相比,加压组和对照组的身体成分均无显著性变化(P>0.05),但加压组出现骨骼肌量增加、脂肪量减少的趋势,加压组体重增加了0.57%,骨骼肌量增加了4.10%,脂肪量下降了1.48%;2)与训练前相比,加压组右上臂紧张围增加(P<0.05),其余围度指标均无显著性变化(P>0.05),加压组上臂围度增加幅度大于对照组;3)与训练前相比,加压组放松状态下的肱二头肌厚度、放松和紧张状态下的大腿前侧肌肉厚度增加(P<0.05),且放松状态下的肱二头肌和大腿前侧肌肉厚度增加幅度较大(26.59%和22.36%);训练后,加压组放松状态下的肱二头肌厚度、放松和紧张状态下的大腿前侧肌肉厚度高于对照组(P<0.05);4)与训练前相比,加压组左膝屈和右膝伸峰值力矩增加(P<0.05),且加压组增加幅度(6.00%和8.87%)大于对照组(5.42%和0.00%);5)与训练前相比,加压组深蹲、卧推、卧拉的最大静力增加(P<0.05);训练后,加压组的卧推最大静力(70.63 kg)显著高于对照组(51.07 kg)(P<0.05),且加压组提升幅度(9.45%)高于对照组(0.46%)。结论:4周自由跤专项训练结合血流限制干预,在保持运动员体重的同时,提高了上下肢主要肌肉的体积,提高了深蹲、卧推和卧拉等的最大力量和局部关节力量,效果优于传统专项训练。

送风方式对高速列车通风和呼吸污染物扩散特性的影响

高速列车交通网络发达且载客量大,但车厢环境封闭易造成污染物的堆积,为提高乘车舒适性和安全性,基于计算流体动力学理论(CFD),建立满载工况的全尺寸车厢通风计算模型.针对排风口位于两侧车窗上端的排风方式,采用速度不均匀系数、温度不均匀系数、能量利用系数和通风效率作为列车通风系统的评价指标,对比研究6种送风方式对车厢内流场特性和呼吸污染物扩散特性的影响,包括多孔顶板送风、下部送风、多孔顶板送风+下部送风、局部多孔顶板送风、侧顶送风、局部多孔顶板送风+侧顶送风.研究结果表明:通过调整风口之间的流量分配比例可以使送风气流均匀地流向客室两侧,改善车内温度均匀性;采用下部送风时,有助于提高通风系统的能量利用系数和通风效率,分别高达1.38和1.21,但会恶化车内乘坐舒适性;通过研究乘客之间呼吸污染物的相互影响情况发现,第C列乘客的呼吸污染物容易向第B列乘客的呼吸区域进行扩散,加剧乘客之间的交叉感染;通过减小多孔顶板的送风口尺寸,采用局部多孔顶板送风可以有效缓解该现象,使污染物的体积浓度下降至0.0019.

高速列车尾车垂向偏置对列车气动性能影响

在长期的高速列车运营过程中,极易形成前后车辆的不同形式偏置,造成列车气动性能改变,甚至可能引发行车平稳性问题,极大影响乘坐舒适性和安全性。以高速列车尾车作为研究对象,探究尾车上下偏置时,高速列车尾部流场变化以及气动特性。基于SST k-ω双方程湍流模型,采用数值仿真方法研究了350 km/h高速列车尾车无偏置、尾车下降20 mm、尾车下降40 mm、尾车下降60 mm、尾车上升20 mm、尾车上升40 mm以及尾车上升60 mm 7种工况下列车的气动性能,分析高速列车气动阻力的变化规律,揭示了不同垂向位移下高速列车尾部流场特性以及列车表面压力分布情况。研究结果表明:高速列车尾部垂向位移对列车整体气动阻力影响较小,但对高速列车气动阻力分布以及流场特性造成一定影响。当尾车偏置位移达到60 mm时,列车车体气动阻力相对于无偏置工况分别降低了-1.11%和2.64%,转向架气动阻力相对无偏置情况下分别降低了11.35%和-17.43%。此外,尾车偏置对列车近尾流区域流场结构有一定影响,尾车鼻锥下方排障器周围漩涡结构由双漩涡结构向单漩涡结构转变;鼻尖处漩涡结构随着尾车高度下降而增大,随着尾车高度上升而逐渐变小。本研究结果丰富了列车尾部偏置情况下的相关研究,对列车检修以及CR450高速列车设计等具有重要指导意义。

Optimization and Algorithm for Through Train Connections at District Stations

In the optimization of train diagrams, selecting the arrival and departure paths of the through gains has a great impact on the dwell time at district stations. In this paper, on the basis of train paths and the through train connection time standard at district stations, we built a mathematical model aiming at minimizing dwell time of through trains at two adjacent district stations, and then converted this into a network flow model to which is added a source and a sink node. Then, we propose a new algorithm for solving the network flow model based on the minimum-cost flow algorithm. A case study for through trains from the Guiyang South Railway Station to the Chongqing West Railway Station shows that the algorithm is reliable and efficient for solving the problem of through train connections, and there is a reduction in the total dwell time that the through trains spend at two adjacent district stations.

The effect of aerobic training on endothelium-dependent vasodilatation in patients with coronary artery disease who were revascularized and young men

Aim: The aim of this study was to determine the effect of training on endothelium-dependent vasodilatation in patients with coronary artery disease (CAD) after revascularization and healthy young men. Background: Impaired endothelial function has been observed in patients with CAD and those with CAD risk factors. Studies have shown that exercise can enhance endothelial function. Methods: This experimental cross-sectional study was conducted on patients with CAD (3 months after CABG and PCI) and students of medical school in 2011. Endothelium dependent dilation of the brachial artery was determined by using high-resolution vascular ultrasonography through flow-mediated vasodilatation (FMD) after induction of ischemia, and the data were analyzed using SPSS, dependent t-test and ANCOVA. Findings: The findings showed that at baseline, FMD was reduced in revascularized patients, when compared with healthy young men, after 8 weeks, and exercise training significantly improved FMD in patients underwent training group [from 4.31 ± 1.45 (SD)% to 6.15 ± 0.773 (SD)%, p p ed unchanged, and even after aerobic training, it did not significantly modify the brachial artery diameter in these groups. Conclusion: Our study demonstrates that endothelial dysfunction persisting in CAD patients after revascularization and aerobic training can improve endothelial function in different vascular beds in CAD patients and healthy young men. This may contribute to the benefit of regular exercise in preventing and restricting cardiovascular disease.

Study on the Organization Model of Wagon Flows in Railway Terminal

Railway terminal is an important part of railway network. Transport organization of railway terminal is the key of the railway transport organization. Moreover, the organization of transport work is based on the organization of wagon flows in the railway terminal. Because of the great amounts of equipment and a large number of train operations, the study on railway terminal transport organization is mostly focused on a marshalling station in railway terminal or a part of it. Systematic study taking railway terminal as a whole is very few. In this paper, the organization of wagon flows in a railway terminal is analyzed and a wagon flow model in a railway terminal is established. The main principles of organization of local trains are also presented.