Islamic glasses from Al-Andalus. Characterisation of materials from a Murcian workshop (12th century AD, Spain)

Rescue archaeological excavations at an urban glass workshop of the 12th century AD in the city of Murcia (Spain) have provided one of the few evidences of glass production in the ancient Islamic territory of Al-Andalus. This paper reports the results derived from a chemical–physical characterisation study carried out on a representative sample set of glass fragments and industrial debris from that workshop. The main objectives of the research were to contribute to the knowledge of the type of glasses produced and provide some insights into the technology developed to obtain different colours in glasses. The resulting data indicated that both high-magnesia plant ash (HMG) soda-lime-silicate and soda-lime lead-silicate glasses were produced. They also indicated a deep knowledge of glass colouring techniques, which suggests that a careful control over the glass melting processes was achieved. Among others, the occurrence of bulk-coloured silver yellow and copper ruby red transparent glasses prove the skills reached by Murcian glassmakers. These results shed new light on the Islamic glass technology of a geographical area in which, up to now, little compositional and technological data from glass workshops were available.     

基于DDS芯片AD9833的低频信号发生器

文章介绍一种基于直接数字频率合成技术（DDS）的低频信号发生器,该系统采用AD9833与ATmega128单片机相结合的方法,以单片机ATmega128为进程控制和任务调度的核心,以DDS芯片AD9833为直接数字频率合成器,实现了输出频率在10Hz～2MHz范围可调,输出信号稳定度优于10。的正弦波、方波和三角波信号。实验证明,此设计硬件电路结构简单,软件控制灵活,输出信号频率稳定,分辨率高。     

我国媒介广告市场集中度分析

市场集中度是通过市场参与者的数量和参与程度来反映市场的竞争或垄断程度的基本概念,通过对报业和电视媒介广告市场绝对集中度指数的计算,分析报业和电视媒介广告市场的市场结构和竞争状况。     

基于FPGA的高速数据采集系统设计

FPGA具有资源丰富、时序快、组成方式灵活、易于修改、并行计算等特点,能够和外部ADC相结合,实现高速数据采集的功能。详细论述了一种基于FPGA和快速模/数转换器AD7862的高速数据采集系统的设计方法,给出AD7862的工作时序及状态机设计的方法,通过QuartusII软件对数据采样模块进行设计及仿真,实验证明能够满足高速数据采集的要求。     

rLent／NT4-NAP及运动对AD模型大鼠的影响

阿尔茨海默病（Mzheimer disease,AD）是一种常见的老年性痴呆症,由于神经元丧失以及神经递质的缺少导致各种认识和认知功能障碍。神经保护肽慢病毒（rLent／NT4-NAP）感染AD大鼠鼻黏膜后能够分泌表达神经保护肽（NAP）,NAP能抑制细胞凋亡,对AD产生保护作用。运动可以对AD大鼠产生有利影响,从而延缓AD大鼠病情。本文采用综述的办法,详细介绍了rLent／NT4-NAP和运动对AD模型大鼠的影响。通过以上论述。为预防、减缓和治疗AD提供相关理论依据。     

Examination‐related anxiety in students diagnosed with AD/HD and the case for an allocation of extra time: perspectives of teachers,mothers and students

This study details the perspectives of Western Australian teachers, students and mothers on the case for an allocation of extra exam time to students diagnosed with Attention‐Deficit/Hyperactivity Disorder (AD/HD). Eighteen teachers of students with AD/HD (14 high and four primary), 15 students with AD/HD (10 high and 5 primary), and their mothers participated in a series of semi‐structured interviews (n = 48). Data analysis revealed that while 56% of teachers and 53% of parents support an allocation of extra exam time for students diagnosed with AD/HD, 67% of students are opposed. This paper details the reasons teachers, parents and students give for their support, ambivalence or opposition to the allocation of extra time for exams.     

AD/HD is a bio‐psychosocial condition requiring support from integrated services

This article reports on how integrated services can provide coordinated support for children with AD/HD and their families. The author reports on the effectiveness of a problem‐based approach to interagency working by exploring the use of two models of good practice from education, health and social care to provide a framework for working across disciplines. It identifies how children with AD/HD could usefully inform professionals and parents about their experience of living with the condition and so influence the services they receive. Suggestions are made as to how the framework can be applied in practice with children and how the framework can be used to identify the effectiveness of support which in turn can inform further research and practice.     

差动变压器的温度补偿方法研究

差动变压器调理电路输出值和输入位移量之间存在着非线性误差和温度漂移。利用传统方法设计和制作高精度差动变压器比较困难。在调理电路中嵌入单片机．利用传感器标定数据建立25℃为基准的温度补偿算法和分段线性插值的温度补偿算法,以提高传感器设计精度。实验结果表明：分段线性插值补偿效果更明显,可以将线性度从室温下的0．5％提高到整个工作温度范围内的0．12％．热灵敏度由原来的1600×10—6／℃提高到70×10-6／℃．具有良好的应用价值。     

游泳动态阻力测试方法探蹊

以自行研制的动态阻力测试仪器探索了一种测量动态阻力的实验方法。通过蛙泳收腿动作划分2阶段的测试和计算后指出:动态阻力受速度的变化影响较小;在较高运动速度下静态阻力占总阻力的比例稍高;动态阻力占总阻力的比例随运动速度的下降而提高。     

湖南本土广告公司竞争优势的培育路径——波特钻石理论在广告业中的应用

从波特钻石理论来看,形成湖南本土广告公司竞争优势的关键有四个要素,正是由于这些因素的合力作用没有得以充分发挥,湖南本土广告公司的现状才不容乐观,因而在此基础上有针对性地探索湖南本土广告公司竞争优势的培育路径和策略势在必行。