Studies of structural reorganization in Nylon 1010 during heating scanning

The process of structural reorganization and thermal history recurrence in Nylon 1010 were studied by using DSC through different heat treatments. The characteristics of both endothermic and exothermic peaks on DSC curve is explained reasonably. The viewpoint is advanced that crystallites assembly is characterized by premelting crystallisation peak. The temperature range sensitive to the crystal perfection is determined. The results provide theoretical basis for the processing and application of Nylon 1010.

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Zusammenfassung Mittels DSC bei verschiedenen Wärmebehandlungen wurde der Vorgang der strukturellen Rückordnung und das thermische Vorleben von Nylon 1010 untersucht. Sowohl exotherme als auch endotherme Peaks an der DSC-Kurve konnten plausibel erklärt werden. Das Kristallitgefüge wird durch einen Premelting Kristallisationspeak bestimmt. Der für die Kristallvollkommenheit ausschlaggebende Temperaturbereich wurde bestimmt. Die Ergebnisse liefern eine theoretische Grundlage für den Umgang und die Anwendungen von Nylon 1010.

     

红外热像仪用于遮蔽烟幕材料性能的测试研究

红外遮蔽烟幕作为一种的高效价廉的光电对抗手段,.被广泛用于搜索跟踪以及制导的激光和红外成像系统的干扰,而遮蔽烟幕的干扰效能由烟幕材料的性能所决定,因此对烟幕材料性能的测试甚为重要.本文讨论了利用红外热像仪对红外遮蔽烟幕材料的性能进行测试的相关技术.首先阐释了红外热像仪测试物体红外辐射的基本原理,其次讨论了在实验室中利用红外热像仪对烟幕性能进行测试的原理,最后分析得到了利用红外热像仪测试烟幕材料性能的计算表达式并得到了相关的结论.     

PS 类Bent函数的一种构造方法

PS 类bent函数类是所有2^(n/2)-1或2^(n/2)-1+1个Fⁿ₂的"不交的" n 2 维子空间的指示函数的模2和所组成的函数的集合.这些函数具有很好的代数结构并在密码学中有很多应用.如何来刻画 PS bent函数的代数范式一直是公开的难题.构造 PS 类bent函数关键在于如何将Fⁿ₂划分为2^n/2+1个 n 2 维子空间.本文给出一种划分的方法,从而构造出 PS 类bent函数,并给出了对应的代数范式.     

分子印迹聚合物膜修饰电极的制备及在香草醛测量中的应用

以香草醛为模板分子,采用光引发聚合法和电化学聚合法分别在电极表面合成了香草醛印迹聚合物,探讨了两种方法的印迹、洗脱及电极再生机理。研究了香草醛在两种电极上的吸附行为,结果表明两种电极均可对香草醛进行吸附富集并进行线性扫描伏安法测定。两种电极均有很好的选择性、稳定性,且各有特点。     

Two-dimensional coupled vibration and equivalent circuit of longitudinal-longitudinal orthogonal composite vibration direction converter

With the advantages of transmitting energy from multiple directions to one direction and transforming vibration from one source to multiple directions, the two-dimensional vibra?tion direction converter has important applications in power ultrasonic technology. However, for the complexity of using the wave equation to design and analysis the two-dimensional vibration direction converter, a concise equivalent circuit for the converter is investigated. By introducing the two-dimensional mechanical coupling coefficient and the longitudinal force transform coef?ficient, and using the electromechanical analogy principle, the equivalent circuit and resonance frequency equation of the two-dimensional vibration direction converter vibrating in anti-phase and in-phase two-dimensional coupled vibration are deduced. The resonance frequencies of the vibration direction converters of two different materials are calculated by using the proposed frequency equation, which are in agreement with the results from the finite element method and the experimental test. It provides a concise method for the design and applications of such ultrasonic vibration system.     

Stable blow-up dynamics in the -critical and -supercritical generalized Hartree equation

We study stable blow-up dynamics in the generalized Hartree equation with radial symmetry, which is a Schrödinger-type equation with a nonlocal, convolution-type nonlinearity: First, we consider the -critical case in dimensions and obtain that a generic blow-up has a self-similar structure and exhibits not only the square root blowup rate , but also the log-log correction (via asymptotic analysis and functional fitting), thus, behaving similarly to the stable blow-up regime in the -critical nonlinear Schrödinger equation. In this setting, we also study blow-up profiles and show that generic blow-up solutions converge to the rescaled , a ground state solution of the elliptic equation . We also consider the -supercritical case in dimensions . We derive the profile equation for the self-similar blow-up and establish the existence and local uniqueness of its solutions. As in the NLS -supercritical regime, the profile equation exhibits branches of nonoscillating, polynomially decaying (multi-bump) solutions. A numerical scheme of putting constraints into solving the corresponding ordinary differential equation is applied during the process of finding the multi-bump solutions. Direct numerical simulation of solutions to the generalized Hartree equation by the dynamic rescaling method indicates that the is the profile for the stable blow-up. In this supercritical case, we obtain the blow-up rate without any correction. This blow-up happens at the focusing level , and thus, numerically observable (unlike the -critical case). In summary, we find that the results are similar to the behavior of stable self-similar blowup solutions in the corresponding settings for the nonlinear Schrödinger equation. Consequently, one may expect that the form of the nonlinearity in the Schrödinger-type equations is not essential in the stable formation of singularities.     

3种现场快速水质检测仪的性价对比

选择了市场上口碑好、占有率高的3款便携式水质现场应急检测设备,通过准确度、精密度、检测时长及价格等指标,以权重积分法对3款仪器进行了比选,结果表明德国MN公司的PF-12型便携式多参数分光光度计的综合性能最优.     

武汉地区科普志愿者发展情况与对策研究

武汉市为贯彻《中华人民共和国科普技术普及法》,按照中国科协第六次代表大会提出的关于"广泛组织志愿者参与科普工作"的要求,于2003年开始组建中国科普志愿者武汉工作团。自此武汉地区科普志愿者队伍在各级科协组织领导下,开展了形式多样、内容丰富的科普志愿服务活动。同时,武汉地区科普志愿者在队伍构成、运行机制、社会影响等方面也存在一定的问题。本文通过问卷等方式,对武汉地区科普志愿者队伍的构成、运行机制、社会影响的现状、问题及其原因进行了分析,在定量调查的基础上,提出发展壮大武汉地区科普志愿者队伍的对策,并对国内其他地区科普志愿者队伍建设提供了一定的借鉴意义。     

基于FFT的二维并行长码捕获算法

导航伪随机长码周期一般为7天,在时间不确定度为±1 s,码速率为10.23 MHz的情况下,需要搜索码片数最多达20 460 000个,普通方法难以实现短时间内捕获。通过增加硬件资源消耗及减少相干积分时间能加快捕获速度,但由于硬件资源有限,而减少相干积分时间会导致捕获灵敏度降低。为了在有限的硬件资源下,不影响捕获灵敏度而又能快速实现捕获,研究了一种基于快速傅里叶变换(FFT)的二维并行搜索算法。通过与传统基于FFT的码相位并行多普勒串行搜索及匹配滤波+FFT方法在捕获时间、灵敏度及硬件资源3方面对比,验证了基于FFT的二维并行捕获方法在长码捕获中具有捕获速度快、捕获灵敏度较高、硬件资源的利用更加合理等优势。     

GBAS功能需求的地面测试研究

星基导航技术在民航界得到了越来越多的应用和推广,GNSS地基增强系统GBAS作为星基导航提供精密进近必不可少的手段之一受到了广泛关注。和陆基导航设备一样,GBAS在正式使用和对外开放之前都需要进行测试和验证,本文阐述了GBAS的基本组成及工作原理,根据国际民航组织的要求,对GBAS在投入使用前需要进行的功能测试进行了概述,并对测量的参数进行了详细的分析说明。给出了GBAS地面功能测试的方法,详细介绍了GBAS精度的测量,为国内运行GBAS提供了技术参考。