微/纳米马达在生物传感中的应用

微/纳米马达是近年来发展的一种可自主运动的新型微/纳米材料,它制备简单、形态多样、可批量化生产,已逐渐应用于生物样品分析及药物运输等领域。由于生物样品成分复杂,传统检测常常需要多步清洗和分离,操作繁琐、耗时较长。微/纳米马达具有自主运动的特性,通过表面生物功能化,可制备成动态的微型生物传感器,实现多种生物分子如核酸、蛋白质、糖蛋白等的实时、快速和灵敏检测。本文总结了近几年微/纳米马达的发展及其在生物传感中的应用,并展望了其在生物分析中的应用前景。     

Control strategy of central pattern generator gait movement under condition of attention selection

As a typical rhythmic movement, human being’s rhythmic gait movement can be generated by a central pattern generator (CPG) located in a spinal cord by self-oscillation. Some kinds of gait movements are caused by gait frequency and amplitude variances. As an important property of human being’s motion vision, the attention selection mechanism plays a vital part in the regulation of gait movement. In this paper, the CPG model is amended under the condition of attention selection on the theoretical basis of Matsuoka neural oscillators. Regulation of attention selection signal for the CPG model parameters and structure is studied, which consequentially causes the frequency and amplitude changes of gait movement output. Further, the control strategy of the CPG model gait movement under the condition of attention selection is discussed, showing that the attention selection model can regulate the output model of CPG gait movement in three different ways. The realization of regulation on the gait movement frequency and amplitude shows a variety of regulation on the CPG gait movement made by attention selection and enriches the controllability of CPG gait movement, which demonstrates potential influence in engineering applications.     

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.     

2021年北京学业水平等级性考试化学卷命题理念的分析*

结合典型试题分析,从基础知识的融会贯通、学科能力的有效发展、学科思想的深入渗透等3个方面,探讨了2021年北京学业水平等级性考试化学卷的命题理念。说明了试题在营造良好教考互动生态、破除机械刷题、衔接高等教育和中学教育过程中发挥的积极作用。     

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。