The Rician inverse Gaussian distribution: a new model for non-Rayleigh signal amplitude statistics.

In this paper, we introduce a new statistical distribution for modeling non-Rayleigh amplitude statistics, which we have called the Rician inverse Gaussian (RiIG) distribution. It is a mixture of the Rice distribution and the inverse Gaussian distribution. The probability density function (pdf) is given in closed form as a function of three parameters. This makes the pdf very flexible in the sense that it may be fitted to a variety of shapes, ranging from the Rayleigh-shaped pdf to a noncentral chi2-shaped pdf. The theoretical basis of the new model is quite thoroughly discussed, and we also give two iterative algorithms for estimating its parameters from data. Finally, we include some modeling examples, where we have tested the ability of the distribution to represent locale amplitude histograms of linear medical ultrasound data and single-look synthetic aperture radar data. We compare the goodness of fit of the RiIG model with that of the K model, and, in most cases, the new model turns out as a better statistical model for the data. We also include a series of log-likelihood tests to evaluate the predictive performance of the proposed model.     

基于80C51F005单片机数据采集系统设计

文章阐述了一种利用新型集成数据采集芯片C8051F005来设计数据采集系统的思路。相对于一般的设计方法，由于其集成度高，且采用了高性能的闪速／电擦除存储器技术，能灵活地对芯片进行编程，方便地解决了数据采集问题，大大降低了数据采集系统的开发时间和系统成本。     

表冷器设计计算的一种新方法

本文从分析盘管内、外侧换热系数着手，提出了表冷器一种新的热工计算方法。     

单壁碳纳米管的制备及生长特性研究

采用Fe/MgO作为催化剂 ,催化裂解CH4制备了较纯的单壁碳纳米管 ,用TEM和Raman对碳纳米管进行了表征 ,对不同生长温度下制备的碳纳米管Raman径向呼吸振动峰 (RBM)进行了分析 ,研究了生长温度对单壁碳纳米管生长特性和结构特性的影响     

Deposition and Properties of Superconducting MgB2 Thin Films

The recently discovered superconductor MgB₂ with T _c at 39 K has great potential in superconducting electronics. In this paper, we review the deposition techniques used for MgB₂ thin films in the light of a thermodynamic study of the Mg-B system with the calculation of phase diagrams (CALPHAD) modeling technique. This thermodynamic study identifies a growth window in the pressure–temperature phase diagram, in which the magnesium pressure is very high for likely in situ growth temperatures. A Hybrid Physical–Chemical Vapor Deposition (HPCVD) technique that successfully achieves such a high Mg pressure is shown to produce in situ epitaxial MgB₂ thin films with bulk superconducting properties.     

Physiology of spinal anaesthesia and practical suggestions for successful spinal anaesthesia

There are numerous physiological effects of spinal anaesthesia. This chapter focuses on the physiological effects that are of clinical relevance to the anaesthesiologist, and provides suggestions for successful management of this simple and popular technique. The mechanisms and clinical significance of spinal-anaesthesia-induced hypotension, bradycardia and cardiac arrest are reviewed. The increasing popularity of ambulatory spinal anaesthesia requires knowledge that long-acting local anaesthetics, such as bupivacaine, impair the ability to void far longer than short-acting local anaesthetics, such as lidocaine. The importance of thermoregulation during spinal anaesthesia, and the clinical consequences of spinal-anaesthesia-induced hypothermia are reviewed. Effects of spinal anaesthesia on ventilatory mechanics are also highlighted. Lastly, the sedative and minimum-alveolar-concentration-sparing effects of spinal anaesthesia are discussed to reinforce the need for the judicious use of sedation in the perioperative setting.     

油库防爆电气设备运行安全管理注意事项

分析了油库防爆电气设备运行中安全管理应注意的几个事项。     

计算机辅助维修性设计与分析中的版本管理

为了支持渐进的和探索武的维修性设计与分析过程，必须进行有效的版本管理。本文研究了维修性CAD框架中版本管理的设计方案以及实现过程。     

田5-斜19五段制剖面定向井钻井技术

五段制剖面定向井施工难度较大，主要介绍了田5—斜19井的井眼轨迹控制、相关安全钻井及钻井液技术，并对施工中发生的复杂情况进行了分析，总结了一些经验，对五段制剖面类型定向井施工具有一定的参考价值。     

动力配煤高温复合固硫剂研究

分析了高温复合固硫剂各成分的作用，实验研究了在不同配比的燃烧试验下，各成分对燃煤着火和燃烧以及对炉渣固硫的影响，得出了该煤种高温复合固硫剂的最佳配方。