基于两个GFSRG的组合随机数发生器

随机数是蒙特卡罗(Monte Carlo)方法的关键因素.首先给出一种广义反馈位移寄存器发生器及其缺点,然后在此基础上提出一种基于两个广义反馈位移寄存器方法的组合随机数发生器,最后给出一些严密的统计检验,结果证明这种组合随机数发生器不失为一种较好的随机数发生器.     

转化思想在解数学题中的应用

通过精选一些实例进行分析和探讨，从七个方面说明转化思想在解数学题中的应用，为搞好解题教学提供帮助。     

组合式因素神经网络系统的数学描述

本文对组合式因素神经网络系统的组成结构进行了分析和论述,作出了数学描述.     

当代社区开展民族传统体育项目的研究

民族传统体育是休闲性的民俗游戏,很少有与古希腊大规模竞技相同和类似的成分,即使是竞技性较强的项目,也与“更高、更快、更强”的奥林匹克竞技导向格格不入。它极具生活情趣,以人为本,运动休闲,突出了丰富的娱乐内容,是社区体育取之不尽的素材。为推动社区体育的发展,以《全民健身计划纲要》为指导思想,结合工作实践经验,对民族传统体育与社区体育的发展进行研究探讨,提出发展对策和自己的看法。     

书信、日记魅力管窥

本文从八个方面探讨书信、日记魅力之所在 :一、缘事而发 ,言之有物 ,有一定的目的、追求和意义。二、晓之以理 ,动之以情 ,有较强的感染力和说服力。三、巧用事实 ,铺陈有序 ,论证有力。四、结构严谨、跌宕多姿、形散而神不散。五、叙述、描写、议论与抒情的完美结合。六、富于哲理和思想意义 ,给人以启迪和教育。七、富于知识性、趣味性 ,给人以美的艺术享受。八、语言生动形象、声调谐和、参差错落、铿锵有声     

脊髓亚急性联合变性24例临床分析

目的探讨脊髓亚急性联合变性（SCD）患者的临床特点、诊断及预后。方法回顾性分析24例SCD患者的临床特点、辅助检查结果、治疗及预后。结果 21例血清维生素B12水平降低。17例行脊柱MRI检查,10例有异常信号,呈条带状等T1长T2异常信号。24例患者均给予维生素B12肌肉注射,14例治愈（58.3%）,6例明显好转（25.0%）,4例效果不明显（16.7%）。结论 SCD患者主要表现为脊髓后索、侧索受累,周围神经受累亦较常见。及时应用维生素B12治疗,症状可明显好转。本病为可治性疾病,预后与病程密切相关,应重视早期诊断、治疗。     

Subdivision surface modeling system based on arbitrary topological curves network and combined subdivision

Arbitrary topological curve network has no restriction in topology structure,so it has more powerful representing ability in defining complex surfaces.A complex surface modeling system is presented based on arbitrary topological curve network and the improved combined subdivision method,its functions including creating and editing curve network,and generating and modifying curve network's interpolated surface.This modeling system can be used to the process of products'concept design,and its applications is ...     

基于反向旅游理论的营销策略研究

反向旅游是一种追求＂景观差异极大化＂的旅游形式,反向旅游市场是一个极具潜力的市场。按照＂极大化差异景观＂的产生原因,可以将反向旅游分为自然型反向旅游、人文型反向旅游和综合型反向旅游。旅游者的反向旅游意向是既已存在且比较强烈的,通过对相应的营销策略的研究,可以起到既能满足旅游者需求,又能实现营销目标的作用。在对反向旅游进行类型划分的基础上,以对北京市民调查结果为依据,结合反向旅游理论和旅游者心理特征,运用经典的4P营销组合理论,从产品策略、价格策略、销售渠道策略和促销策略四个方面提出反向旅游营销策略。     

热电冷联产系统建模与优化研究

针对热电冷联产系统的工作原理进行研究,并对该系统的常用优化方法、策略进行了对比介绍,提出了实现热电冷联产系统技术最优运行模型。对热电冷联产系统中的脱机过程和联机过程的分别进行了优化研究,给出了优化的基本思路。最后对热电冷联产系统的优化过程进行了详细描述,通过对系统模型的主要参数、工作过程进行建模,并通过相互之间的约束关系分析,得到了模型的优化结果。     

University physics students’ ideas of thermal radiation expressed in open laboratory activities using infrared cameras

Background: University physics students were engaged in open-ended thermodynamics laboratory activities with a focus on understanding a chosen phenomenon or the principle of laboratory apparatus, such as thermal radiation and a heat pump. Students had access to handheld infrared (IR) cameras for their investigations.

Purpose: The purpose of the research was to explore students’ interactions with reformed thermodynamics laboratory activities. It was guided by the research question: How do university physics students make use of IR cameras in open-ended investigation of thermal radiation as a phenomenon?

Sample: The study was conducted with a class of first-year university physics students in Sweden. The interaction with the activities of four of the students was selected for analysis. The four students are males.

Design and methods: We used a qualitative, interpretive approach to the study of students’ interaction. The primary means of data collection was video recording of students’ work with the laboratory activities and their subsequent presentations. The analysis focused on how IR cameras helped students notice phenomena relating to thermal radiation, with comparison to previous research on students’ conceptions of thermal radiation.

Results: When using the IR camera, students attended to the reflection of thermal radiation on shiny surfaces, such as polished metals, windows or a whiteboard and emissive properties of surfaces of different types. In this way, they went beyond using the technology as a temperature probe. Students were able to discuss merits and shortcomings of IR cameras in comparison with digital thermometers.

Conclusions: With the help of IR cameras, university physics students attend to thermal phenomena that would otherwise easily go unnoticed.