用6805实现宽范围高精度频率测量

采用ＭＣ６８０５系列单片机并充分利用其定时器，选择测频法或测周法，可以实现定范围、高精度频率测量。此种方法只占用１个内部定时器，节省了硬件开销。     

不锈钢及镍基堆焊层厚度测量

叙述了运用磁性法或超声法对核电和化工容器中不锈钢及镍基堆焊层厚度进行测量的原理、方法及主要影响因素 ,比较了这两种方法的测量结果     

Dynamics and biogeochemical significance of the physical environment in Lake Biwa

We have examined two aspects of the dynamics and biogeochemical significance of the physical environment in Lake Biwa. One is the horizontal distribution of cyanobacteria as it relates to the ‘first gyre’ in the north basin of Lake Biwa. We could easily measure the first gyre using a vessel‐mounted acoustic doppler currents profiler. We were able to quantify the dynamics of the horizontal and vertical structure of currents and water temperature of this gyre. The first gyre did not remain at a fixed position; it moved north and south according to the growth of the gyre. This may play a role in the redistribution of cyanobacteria from place to place in the north basin. The second important environmental dynamic we measured was oxygen consumption rates from 1994 to 2000. We found that the minimum oxygen concentration in the hypolimnion has a clear inverse relationship with the apparent oxygen consumption rates in the 80–85 m depth layer. As a reduction in oxygen concentration in the hypolimnion can have a serious impact on benthic organisms, we concluded that the Lake Biwa environment should be monitored carefully and systematically.     

全站仪在直升机悬停测试中的应用

介绍了如何将改造后的全站仪应用于直升机悬停性能测试的方法。经真实飞行试验检验，该方法理论严密，方案合理，改装简单，操作方便，成本低廉。较之原始的摄影测量法有无法替代的优点。     

测定钠中杂质的手动阻塞计的研究

文章介绍了测定钠中杂质浓度的手动阻塞计的原理、装置和实验结果。为了减少测量误差,我们研究了影响准确测定阻塞温度的因素,并且找到了减少测量误差的办法。在同样的杂质饱和温度下,该阻塞计测得的高、低阻塞温度所对应的杂质浓度差是很接近的。对氧其差值为1.03ppm;对氢为0.0763ppm。     

基于充放电原理实现的微电容测量电路

具有抗分布电容以及简单实用等特性的充放电电路是目前微电容测量中广泛采用的一种测量电路。本文对基于充放电原理的微电容测量电路进行了深入研究，并介绍一种基于充放电原理的实用电路。     

Fringe probing of an evaporating microdroplet on a hot surface

The phenomenon of droplets impacting and evaporating on a hot surface is of interest in many areas of engineering. Quantitative measurement of these processes provides great help to reveal the physics behind. A novel technique was developed to quantitatively measure the volume evolution and contact diameter of an evaporating microdroplet on a hot surface utilizing interference fringe scattering method. In this method, fine fringes produced by the interference of two coherent laser beams was scattered by the droplet and projected onto a screen. The profile and volume of the droplet can be derived from the spatial fringe spacing on the screen. The number of total fringes measurable on the screen was used to determine the instantaneous contact diameter of the microdroplet. Validation experiments demonstrated that the measurement errors are less than ±5% and ±1% for microdroplet volume and contact diameter, respectively. By using this method, the dynamic of droplet impingement, evaporation and boiling using ethanol, pure water and water solution of a surfactant (sodium dodecyl sulfate) with impact velocity of 7.5 m/s and diameters ranged from 0.19 to 0.46 mm were investigated.     

Growth Stresses in the Oxide Scales on TiAl Alloys at 800 and 900°C

In the oxidation of TiAl alloys, the role of scale-growth stresses formed during oxidation has, thus far, been unknown. In the present paper the oxide-growth stresses were investigated by the deflection-test method in monofacial oxidation (DTMO) accompanied by acoustic-emission measurements. On unmodified surfaces the growth stresses are compressive and reach levels of around –100 MPa. At the same time, significant acoustic emission occurs indicating that even under isothermal conditions, stresses are relieved by a scale-cracking mechanism. For oxide scales on TiAl surfaces, which had been ion implanted with chlorine before oxidation, a very thin protective alumina layer is formed which, however, develops growth stresses in the range of several GPa, accompanied by intensive acoustic emission. In all stress–time curves, a dynamic situation is observed. This consists of phases of stress relief by scale microcracking and phases of stresses increase due to crack healing and further oxide growth. As a result, the level of stress as a function of oxidation time, is characterized by an oscillating course.     

平面近场测试系统在天线测试和诊断中的应用

介绍了天线近场测量的基本原理和HD-1型平面近场测试系统,并对近场测量在实际天线测试中的应用情况、发展方向和应用前景等作了简单的描述。     

固井声幅-变密度测井的影响因素分析

利用声幅－变密度测井进行固井质量的评价受到诸多因素的影响，各种影响因素对声幅－变密度测井资料的影响作用有较大的差异，根据大量测井资料分析和实验研究，对仪器偏心、测井时间，套管尺寸与重量，地层岩性，气侵、水泥环微间隔等因素的影响作用进行了较为深入的分析，为各种影响因素的识别与校正提出了相应的方法和依据。