在氨水潮湿面固化的胶粘剂——在处理小化肥厂“跑冒滴漏”的应用

小化肥生产中的设备、管辺等,或因本身存在的沙眼气孔等缺陷、或在各种温度下经水(火)气、氨水长期腐蚀、或在压力下遭受气液、物料和(火)尘的冲击等原因,均会产生腐蚀穿孔、泄漏损坏,从而导致生产过程中出现严重的“跑、冒、滴、漏”现象,大大地影响生产效率。目前,国内已有采用氟(木向)胶和硅楠胶的垫片制品代替石棉垫或盘根,对解决化工生产上的阀门和管辺连接卩位的泄漏问题,取得了良好的效果。但对设备和管辺的腐     

基于法布里-珀罗干涉仪的高灵敏度光纤传声器

论文系统完整地描述了基于法布里-珀罗干涉仪的高灵敏度光纤传声器的研究,内容包括法布里-珀罗干涉仪、光强度解调和电压输出. 根据基本原理分析和计算,通过对结构紧凑传感头、放大的自发辐射(ASE)宽带光源与密波分复用器(DWDM)选配组合的相干光源以及跨阻和前置放大电路的设计,制作完成了光纤传声器. 该光纤传声器具有高灵敏度值为247 mV/Pa,在频率范围30 Hz～4 kHz内的平坦度小于2 dB,以及高信噪比和低总谐波失真.      

纳米材料与物理学

简述了纳米材料的发展过程,讨论了纳米材料的电子结构,提出了纳米材料研究中的物理问题。     

SELF-ORGANIZED FORMATION OF HEXAGONAL NANOPORE ARRAYS IN ANODIC ALUMINA

Conditions for a self-organized formation of ordered hexagonal structure in anodic alumina were investigated, using oxalic or sulphuric acid as an electrolyte. Highly-ordered nanopore arrays with pore densities of 9×10⁹-6.5×10¹⁰cm^-2 and high aspect ratios over 3000 were fabricated by a two-step anodization process. The array exhibits characteristics analogous to a two-dimensional polycrystalline structure of a few micrometres in size. The interpore distance can be controlled by changing the electrolyte and/or the applied voltage. The formation mechanism of ordered arrays is consistent with a previously proposed mechanical stress model, i.e., the repulsive forces between neighbouring pores at the metal/oxide interface promote the formation of hexagonally ordered pores during the oxidation process.     

AuPd CATALYTIC NANOPARTICLE SIZE EFFECT ON THE FORMATION OF AMORPHOUS SILICON NANOWIRES

Amorphous silicon (a-Si) nanowires have been prepared on SiO₂/Si substrates by AuPd nanoparticles / silane reaction method. Field-emission scanning electron microscopy and transmission electron microscopy were used to characterize the samples. The typical a-Si nanowires we obtained are of a uniform diameter about 20 nm and length up to several micrometers. The growth mechanism of the nanowires seems to be the vapor-liquid-solid mechanism. The catalytic particle size effect on the formation of the nanowires and the cause of forming amorphous state Si nanowires are discussed.     

基于互补型光栅编码的相位展开

为了解决在运用相移技术和二元光栅编码结构光进行相位展丌时存在的误码问题,提出了一种新的互补型二元光栅编码.通过多投一幅格雷码图案,并利用格雷码相邻码字之间Hamming距离为1的特点,没计出互补的两种编解码方式.利用两种编码出现误码位置的不同,并结合相移技术解决了去包裹过程中的误码问题.论述了互补型二元光栅编码的设计方法及特点,并详细分析了基于互补型二元光栅编码的相位展开过程.计算机模拟和三维重建实验清楚地表明,提出的互补型光栅编码能很好地解决了误码问题且具有很高的可靠性.     

Shape-Controlled Synthesis and Related Growth Mechanism of Pb（OH）2 Nanorods by Solution-Phase Reaction

We present a simple method to synthesize Pb（OH）2 nanorods by solution-phase reaction. Rod-like lead hydroxide precipitates are obtained by mixing lead nitrate with a concentration of about 0.01 M and potassium hydroxide with concentration of about O.03 M in an aqueous solution. Sodium chloride as an additive is premixed with the lead nitrate aqueous solution. The presence of chloride ions in the precursor solution results in the rod-like morphology of lead hydroxide precipitates. The growth mechanism of the lead hydroxide nanorods is discussed.     

热释电复合材料PZT－PVDF的介电性与热释电性

制备了ＰＺＴ－ＰＶＤＦ热释电复合材料，并利用Ｘ射线衍射仪、扫描电镜和差热分析仪，分别对热释电复合材料的晶体结构、表面形貌和相变进行了分析．采用电桥法和Ｂｙｅｒ－Ｒｏｕｎｄｙ法分别测量了热释电复合材料的介电常数和热释电系数，讨论了热刺激电流对热释电系数测量的影响，得到了１００℃时热释电系数ｐ为１４ｎＣ／ｃｍ２℃、品质因数ｐ／εｒ为０．２５ｎＣ／ｃｍ２℃的热释电复合材料     

直杆横截面上应力公式推导的教法

本文对材料力学中直杆横截面上应力计算公式的推导进行改进,引入单元体,通过对一点处的应力状态和各应变的分析,首先明确横截面上有何种应力及与何应变有关后,再分析相应的应变规律直至推出公式,如此教法可加强对应力状态的理解,为后续内容打好基础。