A theoretical and experimental study on no-guide light pen type 3D-coordinate measurement system

A novel no-guide light pen type 3D-coordinate measurement system with three sets of position sensitive devices (PSDs) to realize intersection converge imaging is introduced. It is called as the light pen type measurement system, because the measuring head is shaped as a pen with several light sources on it. The structure design, measurement principle and experimental results are presented. The theoretical analysis and experimental results prove that this system has advanced features of simple structure, high automation, and high accuracy, and can be used in the measurement fields of mechanical manufacture, robot, auto, aviation and medicine effectively.     

Optical Properties of ZnFe2O4—SiO2 Granular Films Prepared by Radio—Frequency Magnetron Sputtering

We report on the optical properties of ZnFe2O4-SiO2 granular films prepared on quartz substrates by the radio-frequency magnetron sputtering method.Post-annealing was performed at different temperatures under flow oxygen atmosphere.The morphology and Structures of ZnFe2O4 nanoparticles were characterized by x-ray different line types in the optical absorption curves of ZnFe2O4-SiO2 granular films.The critical transition of line types occurs when ZnFe2O4 changes from amorphous to crystalline,and the transition temperature increases with the increasing content of ZnFe2O4.There is an obvious blueshift of the optical absorption edge of the granular films with the decreasing annealing temperature.     

Sound Field Calculations of Elliptical Pistons by the Superposition of Two—Dimensional Gaussian Beams

We present an alternative approach to calculate the sound field of ultrasonic transducers.The distribution function of sources is expanded into the superposition of a series of two-dimensional Gaussian functions.The corresponding radiated sound field is expressed as the superposition of these two-dimensional Gaussian beams and is then reduced to the computation of these simple functions.This treatment does not require the condition that the shape of the source is of circular axial symmetry.A numerical example is presented for the uniform elliptical piston transducer and this is in good agreement with the results given by complicated computation.     

Fluorescence Microscopy of Nanoscale Silver Oxide Thin Films

The experimental conditions for photoactivated intermittent fluorescence from nanoscale silver oxide were studied with fluorescence microscopy.Strong fluorescence was observed from the Ag2O particles with size of 10-20nm excited with both blue and green light .We observed the saturation of Photoexcitation with blue light and explained the experimental results using the model of agglomeration of silver atoms to form small clusters and the fluorescence of Ag2 and Ag3 clusters.     

在白噪声分析中的广义维里拉普拉斯

一类广义维里拉普拉斯，把在白噪声分析构架中通常定义的维里拉普拉斯作为特殊情形而包含。     

稀土元素ICP—AES法摄谱数据的简便处理

本文用PC－1500微机以三次多项式拟合的方法处理稀土元素ICP－AES法摄谱数据，讨论了实验方面的有关问题，提出了一套较为简便的实验方法。通过人工合成样分析及磷矿基体中的加料回收实验，证明本法符合实用要求。     

JY70P等离子体光量计通讯功能的开发

最近我们从法国引进了一台等离子体光量计。本文介绍了在该仪器上开发通讯功能的一种方法，在仪器内部手稿接口板，接上数据传输线，编制通讯软件并使其纳入到原系统软件模块中去，从而完成了异型机之间的PASCAL操作系统下的通讯功能的开发任务。     

等离子体发射光谱法同时测定铬铁矿中铬、铁、镁和铝

铬铁矿属难熔矿种之一，经典分析方法在铂金坩埚内过氧化钠半熔，容量法测定铬、铁离子交换分离富集后，再用容量法或比色法测定其它元素，分离手续繁杂，耗费试剂多，周期长。等离子光谱（ICP）技术具有稳定性好、灵敏度高、线性范围宽、化学干扰少、多元素同时测定等优点，但由于仪器进样量和雾化效率受测定溶液含盐量的限制，试样前处理通常用酸分解，或碱熔后经沉淀分离除去大量可溶性盐类，用酸溶液沉淀，定容，待测。本文利用ICP上述优点对碱熔试样不经分离直接酸化，对高倍稀释试液测定铬铁矿中的主量元素进行了探讨。试验表明，此设想是可行的。本文还就试样的分解条件、酸度、元素间的光谱干扰作了研究，拟出了同时测定铬铁矿中铬、铁、镁、铝的分析方法。本法 质矿产部标准试样的结果与推荐值对照，符合要求。本法称取试样量少，试剂用量少，用银坩埚代替昂贵的铂坩埚，不经分离直接酸化后同时测定4种主量元素，大大简化了操作手续，为分析铬铁矿中主量元素的含量寻找了一条准、快、省的途径。     

浅谈油田开发钕铁硼永磁体温度和环境对其性能的影响

本文简述了工作温度和环境对油田开发用钕铁硼永磁体磁性能的影响，并探讨了改善钕铁硼永磁体耐热、耐蚀性的方法。     

Brick Walls for Nonstationary Black Holes

The validity condition of the brick-wall model is analysed in nonstationary space-time.It is shown that the model holds only in thin regions,only by using tortoise coordinates near the event horizon of a slowly varying(quasistationary)black hole.The reason for the use of tortoise cooridnates is that the stationary state solutions of quantum field equations in other coordinates do not exist for any region in nonstationary space-time.Meanwhile,the quantum corrections to the entropy of the Vaidya-Bonner black hole due to the spin fields are calculated in terms of the brick-wall model.