μA级低功耗流量检测仪的设计

针对目前的流量检测仪在缺乏供电的场所无法对流量进行连续监测的问题,提出一种以零功耗磁敏传感器为信号采集前端,以低功耗MSP430F413单片机为控制器的流量检测仪的设计方法.介绍其工作原理和关键芯片的选型、硬件电路和软件流程.用此方法设计的流量检测仪功耗只有μA级,采用普通锂电池供电,非常适合在没有通电的地方使用.     

Nonlinear rheological behavior of silica filled solution‐polymerized styrene butadiene rubber

The reinforcement and nonlinear viscoelastic behavior have been investigated for silica (SiO₂) filled solution‐polymerized styrene butadiene rubber (SSBR). Experimental results reveal that the nonlinear viscoelastic behavior of the filled rubber is similar to that of unfilled SSBR, which is inconsistent with the general concept that this characteristic comes from the breakdown and reformation of the filler network. It is interesting that the curves of either dynamic storage modulus (G′) or loss tangent (tan δ) versus strain amplitude (γ) for the filled rubber can be superposed, respectively, on those for the unfilled one, suggesting that the primary mechanism for the Payne effect is mainly involved in the nature of the entanglement network in rubbery matrix. It is believed there exists a cooperation between the breakdown and reformation of the filler network and the molecular disentanglement, resulting in enhancing the Payne effect and improving the mechanical hysteresis at high strain amplitudes. Moreover, the vertical and the horizontal shift factors for constructing the master curves could be well understood on the basis of the reinforcement factor f(φ) and the strain amplification factor A(φ), respectively. The surface modification of SiO₂ causes a decrease in f(φ), which is ascribed to weakeness of the filler–filler interaction and improvement of the filler dispersion. However, the surface nature of SiO₂ hardly affects A(φ). © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2594‐2602, 2007     

NiAl基复合材料的研究进展

为了提高NiAl合金强度，改善NiAl合金塑性，在制备NiAl复合材料时，用不同的制备方法在NiAl合金中加入增强剂，如陶瓷或金属颗粒、晶须、短纤维和长纤维等制成复合材料，以不同的增强剂为基础总结了NiAl基复合材料研究在制备、结构、性能及机理等方面的最新进展。     

SiH4激光等离子体内自由基反应动力学研究

本工作采用时间分辨的OES(Optics Emission Spectroscopy)技术,研究横向激励大气压(TEA)CO₂激光诱发的SiH₄等离子体内碎片反应动力学过程。实验结果表明,等离子体内某些碎片的发光特征谱线主峰位置明显不同。据此,讨论了各碎片的产生及反应过程。比较各碎片发光的持续时间及综合其它OES结果,我们认为SIH₄激光等离子体的最终反应通道为产生Si的通道。 关键词：     

Preparation of dye-loaded SiO2 nanoparticles

A room temperature method for the encapsulation of pyrene in SiO₂ nanoparticles is described. The relation between alkoxysilane surfactant chain length, reactant molar ratios and the uptake of dye, sample morphology, photophysical properties, and the ability of the silicate matrix to protect the encapsulated dye was examined. The synthesis can easily be adapted for the encapsulation of other hydrophobic and thermolabile substances, and used in the development of nanostructured optically active coatings, films and monoliths.     

在 VISUAL FOXPRO 6.0 教学中应注意的问题

Microsoft Visual FoxPro6.0是优秀的小型数据库管理系统。从数据库中各表之间的关系、函数的重要性、以制作查询表单为核心以及与其他软件的相关性等方面,阐述了教授该软件时应注意的问题。     

双向HFC网上行传输的技术问题及对策

文章对有线电视双向HFC网上行传输的若干技术问题作了较详细的研究;阐述了双向HFC网传输通道中的特有问题——“汇集干扰”、“汇集均衡”等概念及形成原因,并通过实例分析;提出了解决双向HFC网中信号存在“汇集干扰”、“汇集均衡”等问题的可行性方案及加强有线电视上行通道安全性的措施。     

歌剧《阿依达》——威尔第悲剧艺术之巅

通过对威尔第的歌剧《阿依达》的理解与分析，阐述了对这部历史巨著的评价。从音乐历史上看，《阿伊达》的最大特点是场面豪华绚丽、旋律优美动听、故事精雕细琢、异国情调浓厚感人。这部歌剧具有民族特色，讴歌了人类的文明和进步，是世界悲剧艺术之巅，是近代意大利歌剧创作的先驱。     

提高学生科技能力,培养信息技术创新人才

培养计算机与电子信息技术的创新人才是信息产业发展的需要．本文介绍我们在培养学生的创新精神 和科技能力,提高学生分析问题和实际解决问题能力等方面的一些思考和具体的做法．     

全球气候变化与塔里木盆地古城绿洲演变关系

我国西部地区地形复杂,气候的地域差异性大.特别是青藏高原的突起给塔里木盆地的环境带来了巨大的变化,导致盆地气温降水的突变.从而使塔里木盆地水流分布状态发生改变,导致盆地中原有的古绿洲的蜕变,进而直接影响到整个人类的发展历史.历史研究表明,塔里木盆地气候服从于全球气候变化,并且与某些人文事件,特别是古城绿洲兴盛与消亡有着十分一致的耦合关系.所以,全球环境变化对古城绿洲发展影响重大.