Discrete event model-based simulation for train movement on a single-line railway

The aim of this paper is to present a discrete event model-based approach to simulate train movement with the considered energy-saving factor. We conduct extensive case studies to show the dynamic characteristics of the traffic flow and demonstrate the effectiveness of the proposed approach. The simulation results indicate that the proposed discrete event model-based simulation approach is suitable for characterizing the movements of a group of trains on a single railway line with less iterations and CPU time. Additionally, some other qualitative and quantitative characteristics are investigated. In particular, because of the cumulative influence from the previous trains, the following trains should be accelerated or braked frequently to control the headway distance, leading to more energy consumption.     

初中物理运动观念的内涵分析及培养策略研究

阐述了初中物理中由运动概念向运动观念转变的过程,对运动观念的定义和表现进行了分析.基于初中物理课程标准,将运动观念分解为运动的属性观、运动的描述观、运动的形式观和运动的规律观4个子观念,对每个子观念的内涵及教学策略进行了讨论,提出了通过创设本原性综合问题情境构建学生运动观念的设想.     

PVCM, PVCD, EPL, and irritable larynx syndrome: What are we talking about and how do we treat it?

Paroxysmal vocal cord movement/motion (PVCM), paroxysmal vocal cord dysfunction (PVCD), episodic paroxysmal laryngospasm (EPL), and irritable larynx syndrome (ILS) are terms used to describe laryngeal dysfunction masquerading as asthma, upper airway obstruction, or functional and organic voice disorders. The differential diagnosis of PVCM, PVCD, EPL, and ILS is critical to successful medical and behavioral management of the patient. During the past 10 years, 27 subjects, ages 15–79 years, were identified to have paroxysms of inspiratory stridor, acute respiratory distress, associated aphonia and dysphonia, resulting in misdiagnosis and unnecessary emergency treatments, including endotracheal intubation, cardiopulmonary resuscitation, massive pharmacotherapy, or tracheostomy. A multifactorial management program is proposed utilizing principles of motor learning, neurolinguistic programming model, respiratory and phonatory synchronization, relaxation techniques, concurrent monitoring of behavioral adjustments, and formal psychological counseling.     

Team-moving effect in bi-direction pedestrian flow

We propose a cellular automation model to simulate team-moving behavior in bi-directional pedestrian flow. The moving rules for double-pedestrian teaming include the constraint that pedestrians remain on adjacent cells. Phase transition, critical density — team number, velocity–density, and flow–density relationships are key component parts of the analysis. Simulations show that team-moving produces significant corridor capacity effects, and effects highly depend on the type of teaming behavior. In daily life, pedestrians prefer traverse teaming; under this bias, as teaming pedestrians increase in number, critical density reduces; that means traverse teaming will weaken the capacity of the corridor. The effect of traverse team-moving is nonlinear, and capacity will continually reduce as the team numbers increase; however, reduction rate will decay. We call this phenomenon, “the marginal utility of team-moving.”     

小孔等离子体运动实验方法

在间接驱动惯性约束聚变的黑腔中,辐射烧蚀的高Z等离子体的流体力学运动过程对激光注入黑腔的效率、辐射场均匀性和通过诊断口的黑腔辐射温度诊断都有显著影响。为研究诊断口在黑腔辐射场中的等离子体缩口过程,用激光产生X光辐射加热低Z泡沫填充的金黑腔诊断口,以激光辐照钛平面靶产生的2～5 keV高能段窄能区X光作为背光源,用X光分幅相机获得了源靶和小孔靶两种靶型的小孔等离子体运动过程图像,研究了X光烧蚀的小孔等离子体的流体力学运动过程,探索了定量测量小孔等离子体面密度的空间分布与时间演化过程的实验诊断方法,初步给出小孔等离子体的面密度。     

多关节人体上肢运动的优化轨迹预测

研究了手端无约束条件下,多关节人体上肢点到点运动优化轨迹的预测. 首先建立了多关节上肢平面运动的动力学模型,根据最小功准则提出优化目标函数,将上肢点到点运动的优化轨迹求解问题转化为两点边值问题,设计了寻优的迭代算法,求得了上肢运动的优化轨迹与相应的速度变化曲线. 仿真结果表明: 平衡点位置或关节力矩平滑地变化,避免了肢体出现急加速-急减速的运动形式,减少了肢体运动时的能量消耗;手端的运动轨迹为近似直线,速度为单峰的钟形曲线,这与上肢优化运动的特征相吻合,也表明最小功准则可以有效预测多关节上肢运动的优化轨迹.      

岩层与地表移动的广义下沉公式

在考虑岩性差异的条件下,推导出了岩层与地表移动的广义下沉公式,最后列举了其应用意义和实例。     

一种固体转动演示测量仪

本文介绍了一种能直观演示固体转动的仪器 ,并介绍了转动惯量的测量方法     

蛋白质分子与配体结合过程构象变化的研究

蛋白质分子与配体的作用模式主要有直接的环区结合及铰链式结合两种方式。针对这两种不同的作用方式,我们提出采用不同的策略进行结合过程的构象研究。对于直接的环区结合模式,通过建立环区主链构象库,来实现蛋白质环区与配体的准柔性对接,并以链霉抗生物素蛋白体系为例对构象库建立的可行性进行了验证计算。对铰链结合方式,采用分步对接的方法进行计算,并具体应用于HIV蛋白酶与其小分子配体的结合过程。计算结果表明,这两种处理方法分别能较好地模拟不同类型的蛋白质与配体结合的的构象变化。     

晶型转变对尼龙11分子链运动的影响

Two crystal forms (α and δ′ form) of nylon 11 were prepared by melting, ice water bath quenching and annealing. The characteristic of chain movement of two forms was investigated using dielectric relaxation spectroscopy in the frequency range from 42 Hz to 5 MHz. The dielectric temperature spectra at different frequencies show that the primary α relaxation corresponding to the chain segment movement is located at higher temperature in α form, indicating the chain segment movement is restricted after δ′→α crystal transition. The activation energy of secondary β relaxation remained almost unchanged for two forms, but the relaxation time was longer and the relaxation strength was weaker for α form, confirming that the local relaxation was also restricted to some extent after δ′→α crystal transition.