Experimental research on performances of the imaging plates applied in gamma-ray imaging

Experimental studies on the basic characteristics of IPs applied inγ-ray imaging are carried out by utilizing isotopic y-ray sources.The 1.25 MeV y-ray sensitivity of the BAS-MS and BAS-TR imaging plates and their enhanced sensitivity by covering appropriate Compton conversion foils are measured based on the studies of the image intensity linear calibration,time attenuation laws and the influence of scanning parameter settings.The energy-dependent y-ray sensitivity of the IPs is also obtained by the studies of the measured sensitivity and the Monte Carlo simulated energy deposition in the IPs'sensitive layer.Furthermore,a method of a sandwich detection structure as well as its primary experimental validations are presented in order to increase the gamma-to-neutron ratio in a y/n mixed radiation field.     

A novel CZT detector using strengthened electric field line anode

In this paper, we report on the design, simulation and testing of a novel CZT detector with an electrode named the Strengthened Electric Field Line Anode (SEFLA). The Strengthened Electric Field (SEF) technique and Single Polarity Charge Sensing (SPCS) technique are implemented. It could achieve the same performance as Coplanar Grid, Pixel Array CZT detectors but requires only a simple readout system. Geant4, Ansoft Maxwell and a self-developed Induced Current Calculator (ICC) package are used to develop an understanding of how the energy spectrum is formed, and the parameters of the detector are optimized. A prototype is fabricated. Experimental results demonstrate the effectiveness of this design. The test shows that the SEFLA detector achieves a FWHM of 6.0% @59.5 keV and 1.6% @662 keV, which matches well with the simulations.     

Laser-Induced Damage Threshold of TiO2 Films with Different Preparation Methods and Annealing Temperatures

Sol-gel TiO2 films are prepared by the dip-coating method and the spin-coating method, and then annealing is performed at different temperatures. The structures, optical properties, surface morphologies, absorption and laser-induced damage threshold （LIDT） at 1064 nm and 12 ns of the films are investigated. The results show that the dip-coating method can be used to obtain a higher LIDT than the spin-coating method. When the annealing temperature increases from 80℃ to 120℃, the dip-coated film obtains a higher LIDT, whereas the spin-coated film obtains a lower LIDT. In addition, the damage morphology is a spalling pit for the dip-coated film annealed at 80℃. When the annealing temperature increases to 120℃, it shows a melting area. For both the spin-coated films annealed at different temperatures, the damage morphologies are the combination of spelling and melting. The differences in LIDT and damage morphologies of the films are discussed.     

一种基于成像板的能量卡阈式快中子图像测量方法

为减小散射中子等较低能量的中子对快中子图像的贡献,提出了在成像板前依次紧贴金属卡阈片和富氢元素薄片的能量卡阈式快中子成像方法.该方法通过改变卡阈片材料、厚度等参数,可有效降低成像结构对某一能段中子的相对灵敏度.以14 MeV中子照相为例设计的能量卡阈式成像结构为TR成像板依次覆盖约150μm Pb膜和500μm聚乙烯膜,计算表明该结构对8 MeV以下快中子灵敏度小于其对14 MeV中子灵敏度的30%.利用K400加速器DT中子源开展了验证实验,结果表明能量卡阈式快中子成像结构能够有效消除样品散射中子引起的边界增强效应.     

基于ROOT的核孔膜生产可视化分析平台

利用核反应堆产生的裂变重离子碎片辐照固体薄膜,是生产核孔膜的主要方式之一。为优化反应堆核孔膜生产工艺参数,应用Geant4模拟计算了热中子辐照铀靶的出射裂变碎片数据,并基于ROOT搭建了核孔膜生产可视化分析平台。平台基于裂变碎片数据开展核孔膜生产过程模拟及分析,并将分析结果可视化展示。平台可分析计算膜厚度、孔隙率、连孔率等关键产品参数,从理论上指导准直角度、入射粒子密度等生产工艺参数。该平台可作为反应堆核孔膜生产中优化工艺参数的辅助工具。     

芋螺毒素lt1c的重组表达及镇痛功能

lt1c是从信号芋螺毒管中发现的一种A超家族毒素多肽,为深入研究其功能,采用pTRX表达系统将lt1c与硫氧还蛋白基因进行融合,转入大肠杆菌进行表达后,通过超声破碎、亲和层析、酶切和凝胶过滤层析等方法,最终得到目的蛋白。组织水平的青蛙坐骨神经-腓肠肌活性研究表明,重组表达的lt1c在6μmol/L浓度下,30 min内完全抑制肌肉的收缩,且其作用可逆。进一步的功能研究发现,lt1c能够抑制热板疼痛模型小鼠的舔足反应,提示A超家族芋螺毒素lt1c可能具有一定的镇痛活性。该研究为筛选新的多肽镇痛药物奠定了基础。     

活性炭电化学气化的工艺条件研究

煤电化学气化相对于传统的煤气化具有反应条件温和、工艺简单以及环境友好等诸多优点,但由于煤结构与成分的复杂性,导致煤电化学气化的研究多年来一直未有较大进展。以活性炭代替煤,在不同工艺条件下研究了活性炭电化学气化的过程中电流随时间的变化以及阳极气体成分与含量。研究结果表明:活性炭电化学气化过程中,阳极的气体产物主要为CO_2,其中含有少量的CO,两者的比例相差1～2个数量级;随着温度、电解电位以及活性炭浓度的提高,活性炭电化学气化反应的电流和气体产量均增加,最佳硫酸浓度为1 mol/L.     

落石冲击作用下X80架空管道力学响应分析

长输管道穿越崩塌多发区域时，时常遭受落石等危岩体的冲击威胁，易造成管道冲击失效，影响管道生产安全运行。如何科学进行落石冲击下管道安全评价，是业界关注的问题之一。文章通过有限元仿真软件建立落石冲击架空管道的力学模型，研究落石形状、管道壁厚、管道内压等工程因素对管道应力应变的影响规律。结果表明，相同质量下，落石形状不同，对管道造成局部凹陷程度也不同，其中，楔形石块对管道伤害最大；落石冲击后的能量减少；落石的最大坑深随着落石冲击速度的增加而增加，随着管道内压和壁厚的增大而减小；此冲击过程中耗散能一直存在。分析结果将为长输管道的铺设和防护提供一定理论依据。     

中国共产党国际战略思想研究

中国共产党国际战略是中国共产党人关于制定国家战略的指导思想和理论形态,它直接影响到执政党和国家治国安邦决策的总路线与工作重心。从中国共产党国际战略的现实依据、思想基础、历史根基和文化底蕴以及实践平台等构成要素及源流入手,有助于我们了解研究中国共产党国际战略思想的重要意义。