俄罗斯第三代电磁探伤仪的应用与推广

在油水井生产过程中,由于周围环境的影响,套管发生变形、损坏和腐蚀,直接影响油田的正常生产。多层管柱电磁探伤测井技术利用电磁感应原理实现对井下多层管柱的腐蚀、变形、裂缝及壁厚进行检测。介绍俄罗斯最新产的电磁探伤测井仪MID-K的原理方法、仪器结构及特点,并用测井资料展示其在单套管和多层管内进行套管检查中良好的应用效果。     

快中子探测器的效率刻度

本文叙述了用n-p散射方法刻度快中子探测器效率的基本原理、实验方法和测量结果。400 keV氘束轰击T-Ti靶,由T(d,n)~He反应得到15.2 MeV的中子,散射体是一个圆柱塑料闪烁体(φ2.2×3cm),飞行距离2m,时间分辨率约1.5ns,效率测量的能区范围为1—14MeV,对多次散射和几何条件作了修正,总的误差约2%。     

PVInSb红外探测器的阻抗——频率特性分析

通过理论计算和实际测试，给出了ＰＶＩｎＳｂ红外探测器的低频阻抗－频率特性曲线，结合检测阻抗／动态电阻的方法和阻抗－频率特性曲线的变化规律，分析讨论了ＰＶＩｎＳｂ红外探测器的阻抗与动态电阻的异同，从而说明在涉及ＰＶＩｎＳｂ红外探测器的阻抗／动态电阻时，即使在低频范围也要具体考虑频率因素的影响。     

CTS-26型超声探伤仪典型故障的分析与排除

在简要介绍CTS-26型超声探伤仪工作原理及组成的基础上。对其几种典型故障作了具体的分析和处理。     

Radiation tolerance of type IIa synthetic diamond detector for 14 MeV neutrons

Radiation tolerance of a type IIa synthetic diamond detector was examined from irradiation of mono-energetic 14 MeV neutrons. Measurements of I–V (current–voltage) characteristics and energy spectrum for 5.486 MeV alpha particles were performed after neutron irradiation. In the I–V characteristics measurement, enhancement of rectification was observed after neutron irradiation of up to 2.0 × 10¹² n/cm². Concurrently with the enhancement of rectification, significant decrease in signal amplitude was observed in energy spectrum measurement for alpha particles. It is considered that these changes were due to increase in the concentration of defects acting as shallow energy levels in the forbidden band. For neutron irradiation of higher than 1.6 × 10¹³ n/cm², weakening of the rectification characteristics and recovery of the signal amplitude were observed. These changes imply that deep energy levels, which were also considered to be introduced by defects, were dominant and weakened the effects of the shallow energy levels. Increase in the concentration of the deep trapping levels resulted in gradual decrease of the signal amplitude and degradation in the energy resolution. The peak for the alpha particles was obtained up to 5.5 × 10¹³ n/cm².     

20μm高灵敏浸没型碲镉汞红外探测器

报道了一种新型高灵敏浸没型ＨｇＣｄＴｅ红外探测器的研制，获得了Ｄ＾＊＝１．４６×１０＾１１ｃｍＨｚ＾１／２Ｗ＾－１，Ｒ＝６０８Ｖ／Ｗ，λｃ（２０％）－２０μ，灵敏元面积Ａ＝０．１２×０．１２ｍｍ＾２，和有效通光孔径ψ＝６ｍｍ的浸没型器件。     

用PSD检测长直导轨准直度

介绍了用光电位置传感器（ＰＳＤ）检测长直导轨的原理和方法。利用ＰＳＤ作为位置传感的检测系统能实时、连续地对被测件三维空间准直度进行检测，更好地解决了以往移动桥板分段测量、人工读数（数格）局部检测的方法存在的问题。     

金刚石光电导探测器研制及在软X光测量中的初步应用

介绍了我们自己设计制造的天然Ⅱａ型金刚石光导探测器的结构，原理，制造工艺，实验标定及其在ＩＣＦ实验中软Ｘ光测量中的应用等。     

A two-stage MMSE multiuser decision feedback detector using successive/parallel interference cancellation

In this paper, we present a novel two-stage minimum-mean-squared-error (MMSE) multiuser decision feedback detector (DFD) for code division multiple access systems working in the frequency-selective multipath fading environment. The first stage of the proposed cascaded structure is the noise-predictive successive DFD (NP-S-DFD), in which the active users are detected successively using the conventional bell labs layered space-time (BLAST) ordering criterion. The second stage includes an adaptive successive/parallel DFD (SP-DFD), which uses the tentative decisions obtained at the first stage for multiuser interference cancellation and data detection. Therefore, the proposed two-stage DFD may be called noise-predictive successive SP-DFD (NP-S-SP-DFD). Simulation results are presented to demonstrate the substantial improvement in the bit error rate performance of NP-S-SP-DFD over the conventional single-stage and cascaded DFDs. It may be inferred that the proposed DFD provides additional performance gain, when the order in which the users are detected is optimized according to the BLAST ordering based on MMSE criterion.     

交通检测器在高速公路中的应用及评价

交通检测器是高速公路管理系统必不可少的组成部分，通过对各种交通检测器的检测原理，特点的分析，对其在高速公路上的应用效果进行了评价。