案例教学法在《火灾证据学》课程中的运用研究

为了培养学员的综合素质和创新能力,《火灾证据学》课程引入了案例教学法。分析《火灾证据学》课程运用案例教学法的教学效果,提出运用案例教学法的基本形式及其相关要求。     

案例教学法在学前教育学课程教学中的运用

学前教育学课程是学前教育专业学生系统学习本专业知识的认知起点,在教学中运用案例教学法能弥补学生对本专业的感性认知和实践经验的缺乏,对于教师的"教"、学生的"学"和师生之间、生生之间的互动都有十分重要而有益的价值。本文诠释了案例教学法的基本内涵,在此基础上论述了案例教学法在学前教育学课程教学中的重要价值,最后探讨了在学前教育学课程教学中案例教学法的实施过程和应当注意的问题。     

Improved bounds for batch scheduling with nonidentical job sizes

Here, we revisit the bounded batch scheduling problem with nonidentical job sizes on single and parallel identical machines, with the objective of minimizing the makespan. For the single machine case, we present an algorithm which calls an online algorithm (chosen arbitrarily) for the one‐dimensional bin‐packing problem as a sub‐procedure, and prove that its worst‐case ratio is the same as the absolute performance ratio of . Hence, there exists an algorithm with worst‐case ratio , which is better than any known upper bound on this problem. For the parallel machines case, we prove that there does not exist any polynomial‐time algorithm with worst‐case ratio smaller than 2 unless P = NP, even if all jobs have unit processing time. Then we present an algorithm with worst‐case ratio arbitrarily close to 2. © 2014 Wiley Periodicals, Inc. Naval Research Logistics 61: 351–358, 2014     

某型自行加榴炮抽筒过程动力学分析

分析了某型自行加榴炮钢质药筒不抽筒产生的原因,简述了火炮抽筒机构改进的措施,建立了抽筒过程的动力学方程,分别对四种方案进行了计算。     

一种基于UML/OCL的软件测试方法

根据UML/OCL和建模环境提供的软件模型信息,以一个武器装备管理信息系统的装备入库顺序图为例,在分析UML/OCL顺序图的语法和对象间的交互信息的基础上产生测试场景,提供了一种基于UML/OCL的面向对象的软件测试方法,并提出测试自动化的设想,对软件测试有一定的借鉴作用。     

Two‐machine flow shop no‐wait scheduling with a nonavailability interval

We study a two‐machine flow shop scheduling problem with no‐wait in process, in which one of the machines is not available during a specified time interval. We consider three scenarios of handing the operation affected by the nonavailability interval. Its processing may (i) start from scratch after the interval, or (ii) be resumed from the point of interruption, or (iii) be partially restarted after the interval. The objective is to minimize the makespan. We present an approximation algorithm that for all these scenarios delivers a worst‐case ratio of 3/2. For the second scenario, we offer a 4/3‐approximation algorithm. © 2004 Wiley Periodicals, Inc. Naval Research Logistics, 2004     

Parallel machine scheduling with batch deliveries to minimize total flow time and delivery cost

Motivated by the flow of products in the iron and steel industry, we study an identical and parallel machine scheduling problem with batch deliveries, where jobs finished on the parallel machines are delivered to customers in batches. Each delivery batch has a capacity and incurs a cost. The objective is to find a coordinated production and delivery schedule that minimizes the total flow time of jobs plus the total delivery cost. This problem is an extension of the problem considered by Hall and Potts, Ann Oper Res 135 (2005) 41–64, who studied a two‐machine problem with an unbounded number of transporters and unbounded delivery capacity. We first provide a dynamic programming algorithm to solve a special case with a given job assignment to the machines. A heuristic algorithm is then presented for the general problem, and its worst‐case performance ratio is analyzed. The computational results show that the heuristic algorithm can generate near‐optimal solutions. Finally, we offer a fully polynomial‐time approximation scheme for a fixed number of machines. © 2016 Wiley Periodicals, Inc. Naval Research Logistics 63: 492–502, 2016     

基于虚拟现实技术的案例式反恐指挥训练

本文探讨将虚拟现实技术引入案例式反恐指挥训练,首先分析基于虚拟现实技术案例式指挥训练的理论依据;对案例式VR反恐指挥训练的流程进行设计,并确定案例式VR反恐指挥训练内容;对训练中应把握的原则进行了明确,研究创新部队指挥训练形式具有参考价值。     

Strain concentration caused by the closed end contributes to cartridge case failure at the bottom

Ruptures at the bottom of cartridges are a common cause of failure of ammunitions, which directly threatens the safety of weapons and shooters. Based on plastic tube theory, this study analyses the radial and axial deformation of a cartridge, considering the radial constraint of the closed end at the bottom of the cartridge. Owing to the influence of the closed end, the bottom of a cartridge does not establish complete contact with the chamber. Owing to strain concentration in the non-contact area, this area is more amenable to the occurrence of cartridge rupture. This theory predicts the location of the fracture more accurately than the traditional theory. The maximum axial deformation of a cartridge comprises bending and friction deformation. The maximum strain at the bottom of the cartridge increased by 135% owing to the introduction of bending strain caused by the closed end. The strain distribution of a cartridge was measured using digital image correlation technology, and the measured result was consistent with the predicted results of the bending deformation theory and rupture case. The effects of wall thickness, radial clearance, friction coefficient, and axial clearance on the axial deformation of the cylinder were studied. Increasing the wall thickness and reducing radial clearance were found to reduce bending deformation; furthermore, lubrication and reduction in axial clearance reduce frictional deformation, which in turn reduce cartridge rupture.     

国内外基础化学教学对比及应用

我国目前基础化学的教学内容和课程体系,应参考美、英、德等国的基础化学教育理念和教学手段,从拓宽教学知识体系、引入学科前沿成果、加强案例素材应用、完善多媒体教学、充分发挥学生的主体作用等方面入手,同时通过多种教学手段尝试和改进,达到激发学生兴趣、提升学生科学素养的目的,以增强教学效果。