基于系统动态学方法的弱信号生命周期建模与仿真

[目的/意义]为增强弱信号的内涵研究，对其全生命周期过程下的各阶段要素以及要素间的联系进行探寻，以期获得一定程度上的理论贡献，同时也为相关组织在开展弱信号管理实践时提供理论指导。[方法/过程]在对弱信号概念研究现状进行梳理的基础上，结合意义构建理论给出了弱信号概念界定。随后，通过与信息生命周期、新兴议题生命周期进行类比，提出弱信号生命周期理念。进而采用系统动态学方法开展系统思考，使用因果回路图进行系统建模，运用存量流量图进行仿真模拟。[结果/结论]弱信号生命周期包含4个阶段：侦测、关联、传递、抉择，相应的系统动态学模型所具备的现实性得到验证，且通过情景模拟确认了4个关键辅助变量：外界噪声干扰程度、弱信号分析效率、组织内相互信任程度、决策者信任程度。在整体研究的基础上，给出弱信号管理过程中可能会遇到的障碍以及应对策略。     

Exploring Developmental Appropriateness of Multitouch Tables in Prekindergarten: A Video Analysis

This study explored how developmentally appropriate practices influenced the affordances of a multitouch surface in an early childhood classroom. Children, ages 4 to 5 years old, were videotaped while engaged in a storymaking application on a multitouch table. As a result of the study, we found that some challenges with the functionality undermined children's autonomous control. The researchers observed numerous instances of issues with control of the medium, including height of the table, sensitivity to multiple types of touch, and limited instructions and prompts. Implications for future research and practice are discussed.     

SAR雷达信号处理技术研究

阐述了SAR雷达主要特点、应用及其信号处理技术的发展状况，研究了SAR雷达信号处理的几个主要技术——宽带信号产生器、高采样率模数变换、脉冲压缩技术、运动补偿技术、SAR成像算法、实时成像处理器、慢速动目标检测和成像技术．对SAR雷达的进一步发展具有深远的意义．     

A kinematic analysis of the spine during rugby scrummaging on natural and synthetic turfs

Artificial surfaces are now an established alternative to grass (natural) surfaces in rugby union. Little is known, however, about their potential to reduce injury. This study characterises the spinal kinematics of rugby union hookers during scrummaging on third-generation synthetic (3G) and natural pitches. The spine was sectioned into five segments, with inertial sensors providing three-dimensional kinematic data sampled at 40 Hz/sensor. Twenty-two adult, male community club and university-level hookers were recruited. An equal number were analysed whilst scrummaging on natural or synthetic turf. Players scrummaging on synthetic turf demonstrated less angular velocity in the lower thoracic spine for right and left lateral bending and right rotation. The general reduction in the range of motion and velocities, extrapolated over a prolonged playing career, may mean that the synthetic turf could result in fewer degenerative injuries. It should be noted, however, that this conclusion considers only the scrummaging scenario.     

表面活性剂增敏光度法测定水样中的微量铁

在HAc-NaAc缓冲溶液(pH=5)存在下,以邻二氮菲(phen)作显色剂,表面活性剂曲拉通X-100对Fe(II)与邻二氮菲的显色反应具有增敏作用,形成的Fe(II)-phen-Triton三元络合物呈红色,络合物的最大吸收波长为510 nm,表观摩尔吸光系数为1.2×105L.mol-1.cm-1,铁含量在0.5~12μg/mL范围内符合比尔定律,用于水样中微量铁的测定,回收率在97.1%~98.0%之间。     

数字电视信号地面发射机整机控制器的实现

控制器是确保发射机实现不间断播出和安全运转的重要部件.本文针对发射机的整机集成,简述了数字电视信号地面发射机的基本组成,重点介绍了发射机整机控制器的原理及所实现的功能.     

用Mathematica绘制几何图形

介绍了Mathematica在几种几何图形绘制中的应用,提出了获得空间旋转曲面的参数方程的一般方法,并给出了用Mathematica绘制空间旋转曲面的实例的源代码.     

全球环境变化使植物体对增强UV-B辐射信号的感受和传导

据国际上的最新研究成果 ,论述了在全球环境变化引起的UV -B辐射过程中 ,植物对UV -B信号的感受和传导机理 ,其中包括细胞中UV -B信号受体 ,各种信号分子 (诸如活性氧、水杨酸、茉莉酸、乙烯和一氧化氮等 )的级联放大传递以及对于基因表达活性的影响 ,提出了UV -B胁迫信号传递的信号分子级联模型 ,从而为有效防护环境变化引起的UV -B辐射增强对于植物体的伤害提供理论依据     

扁椭球面内铣刀半径的最大解

介绍了实际生产过程中加工内扁椭球面时,求算合适铣刀半径的问题,通过推导,给出了求算最大铣刀半径公式和推荐适当的系数,以便机床操作者和工程技术人员参考选用。     

关于泄洪洞水力设计中空蚀问题的探讨

首先介绍了空蚀破坏的原理以及发生空蚀破坏的条件，并分析了龙抬头式泄洪洞发生空蚀破坏的原因和易发生空蚀破坏的部位。最后，结合工程实例的实验结果，说明了发生空蚀破坏的主要原因是不平整度以及体型的不合理。