纯碘化铯(CsI)晶体的发光与光衰减特性研究

纯碘化铯晶体是一种具有快衰减闪烁特性的新型辐射探测材料, 在伽马射线、中子和其它辐射探测技术中有重要的应用前景。本研究以Bridgman法所生长的纯碘化铯为对象, 分别研究了该晶体的透射光谱以及在紫外光、连续X射线、脉冲X射线和宇宙射线激发下的发射光谱、时间响应特性和沿晶体生长方向不同部位的光输出分布特点。实验测得晶体的吸收边为240 nm, 激发和发射波长分别位于241 nm和318 nm, 发光衰减时间分别为2~3 ns和18~25 ns。以尺寸为30 mm×30 mm×200 mm的晶体籽晶端和尾端与PMT耦合所测得的光输出分别是143 p.e/MeV和127 p.e./MeV, 尽管晶体两端的光输出存在12.6%的差异, 但没有观察到衰减时间长于100 ns的慢分量。这些性能进一步证明纯碘化铯晶体具有作为快闪烁体的优势。     

钨酸铅晶体的发光光谱及辐照诱导色心的研究

概要介绍了纯钨酸铅晶体和不同掺杂钨酸铅晶体发光光谱及辐照性能的研究结果．测量了晶体的光致发光和辐射激发发光光谱,比较了辐照诱导色心的密度和辐射发光光谱之间的关系．详细分析了钨酸铅晶体辐照诱导色心密度的分布,根据辐照诱导色心模型,计算了色心的能量及分布．     

反应蒸发制备nmSi-SiOx发光薄膜

报道了用真空反应蒸发制备nmSi/SiOx 薄膜 ,制备出含有不同纳米尺寸硅颗粒的薄膜 ,研究了不同条件下得到的nmSi SiOx 薄膜的结构和组分。实验发现以SiO为蒸发源制备的薄膜能够实现光致发光。初步分析nmSi SiOx 薄膜发光机制可能是由纳米硅量子效应引起的 ,界面效应和缺陷对薄膜PL可能没有贡献 ,解释了有纳米硅颗粒存在但观察不到PL的原因     

等离子体平板显示用发光材料

本文介绍了ＰＤＰ用荧光粉的基本情况及其应用特性。归纳出基团敏化带位置的一般规律及阳离子对基团敏化带波长位移的影响，并指出，提高发光效率，改善荧光粉的热稳定性和辐照稳定性，开发新型稀灾粉等具有重要意义。     

Ce3+掺杂氧化物玻璃的发光特征

制备了掺铈硼酸盐、硅酸盐、磷酸盐和锗酸盐等玻璃样品，测试了激发光谱和发射光谱，结果表明，随着玻璃光碱度的增大，即从磷酸盐到锗酸盐，Ce^3 的激发峰值波长从290nm到380nm，发射峰值波长从349nm到480nm，表现出强烈的Nephelauxetic效应，Stokes位移从50nm到100nm。较长的激发波长和发射波长有利于闪烁光在玻璃中的透过。较大的Stokes位移可以减少发射光的自吸收。作为玻璃闪烁体的基质，建议硼硅酸盐、硅酸盐和锗酸盐玻璃是比较合适的，本文为研制高密度玻璃闪烁体打下基础。     

GaP纳米复合发光材料的制备和性质

用微波水热方法制备了GaP纳米晶／桑色素复合发充材料，研究了粒度对复合材料发光波长及发光效率的影响。结果表明：在微波水热条件下，GaP纳米晶的晶体结构不发生变化，只是在复合反应后粒度有所长大；与纯CaP纳米晶的发光光谱相比，复合后材料的发光峰变窄，发光强度显著增加，而且发光峰峰位向短波方向移动；另外，复合材料的发光波长和效率与GaP纳米晶的粒度有密切关系，粒度减小时相应的复合材料发光波段蓝移且发光效率提高。     

煤块冲击破碎速度研究

冲击破碎速度是影响煤块冲击破碎效果的主要参数。基于分段塑变碰撞模型得到煤块与冲击板碰撞时的接触应力,并结合裂缝假说和能量守恒原理推导出煤块被破碎到指定粒度需要的理论冲击速度。进行煤块冲击破碎试验,通过试验数据分析得到了冲击破碎速度的试验拟合公式和理论修正公式。88%的拟合计算值与试验值的误差小于10%,但拟合公式结构复杂,不适合工程应用;85%的理论修正值与试验值的误差小于20%,满足初级破碎所需的精度,可以作为初级破碎时冲击破碎速度的理论选择依据。     

反应蒸发制备nmSi—SiOx发光薄膜

报道了用真空反应蒸发制备ｎｍＳｉ／ＳｉＯｘ薄膜,制备出含有不同纳米尺寸硅颗粒的薄膜,研究了不同条件下得到的ｎｍＳｉ－ＳｉＯｘ薄膜的结构和组分,实验发现以ＳｉＯ为蒸发源制备的薄膜能够实现光致发光。初步分析ｎｍＳｉ－ＳｉＯｘ薄膜发光机制可能是由纳米硅最子效应引起的,界面效应和缺陷对薄膜ＰＬ可能没有贡献,解释了有纳米硅颗粒的存但观察了ＰＬ的原因。     

多孔硅发光

根据最近几年大量的文献报道,综述了关于多孔硅制备、发光等方面的研究结果,并简要介绍了国内一些单位的工作。     

YAG:Yb~(3+),Tm~(3+)纳米晶粉体的制备及其蓝色上转换发光

以稀土氧化物、硝酸铝为原料,采用溶胶-凝胶法合成了Yb3+、Tm3+共掺的钇铝石榴石(Y3Al5O12,YAG)纳米晶粉体。采用X射线衍射(XRD)确定了1200℃煅烧后的晶体粉为纯YAG结构,无杂质相,晶体尺寸约为90nm;该粉体在波长为980nm的半导体激光器激发下发射出中心波长为487nm的蓝色上转换荧光,对应于Tm3+离子的1G4→3H6的跃迁。发光强度和激发功率关系的研究揭示了其为双光子过程,Tm3+的激发态吸收及Tm3+、Yb3+间的交叉驰豫型能量传递和是该上转换发光的主要机制。     

Afterglow emission from xenon, krypton, and argon dimers in nanosecond volume discharge at elevated pressures

The emission characteristics of plasma of a volume discharge initiated by electron avalanche beams in heavy inert gases at pressures up to 1.5 bar have been studied. It is established that more than 90% of the energy radiated in the wavelength range from 120 to 850 nm is emitted from xenon, krypton, and argon dimers. In the case of excited xenon plasma, an output radiation power of ～300 kW and an energy of 45 mJ per cubic centimeter were obtained.     

建立一种氪氙原料气中氪气和氙气含量的分析方法

介绍一种全新的氪氙原料气中氪气和氙气含量的分析方法。该方法能够准确测定生产过程中氪氙原料气中氪气和氙气的组分含量,有效降低生产能耗和提高产品产量。     

Self Diffusion and Binary Maxwell–Stefan Diffusion in Simple Fluids with the Green–Kubo Method

Self-diffusion coefficients and binary Maxwell–Stefan diffusion coefficients were determined by equilibrium molecular dynamics simulations with the Green–Kubo method. The study covers five pure fluids: neon, argon, krypton, xenon, and methane and three binary mixtures: argon+krypton, argon+xenon, and krypton+xenon. The fluids are modeled by spherical Lennard-Jones pair-potentials, with parameters which were determined solely on the basis of vapor-liquid equilibrium data. The predictions of the self-diffusion coefficients agree within 5% for gas state points and about 10% for liquid state points. The Maxwell–Stefan diffusion coefficients are predicted within 10%. A test of Darken's model shows good agreement.     

氪气产品氧含量超标的分析及处理

在氪氙精提取装置运行过程中,由于分子筛吸附器前的换热器换热效果不理想和分子筛吸附器入口泄漏等原因,导致氪气产品中的氧含量超标。采取相应措施排除故障后,保证了氪氙精提取装置的稳定运行,使氪气产品质量达到了国家标准的要求。简介氪氙精提取装置的流程,详细介绍原因分析过程和处理方案的实施及其效果,最后总结由此获得的体会。     

AGC氦放电离子化检测器(DID)气相色谱仪在特种气体分析中的应用

随着气体行业的发展,尤其是特气行业的发展对气体分析仪器的要求更高,在这样的条件下,AGC公司氦放电离子化检测器(DID)气相色谱仪及时解决了分析行业的难题.着重概述在高纯氦气、高纯氪气、高纯氙气、高纯氯化氢气体、砷烷等特气分析中的应用.     

Assessment of multiphoton absorption in inert gases for the measurement of gas temperatures

A spatially resolved optical technique to measure gas temperature was assessed. The technique relies on multiphoton absorption in inert gases. In contrast to laser-induced fluorescence, absorption is insensitive to collisional deactivation, and, in contrast to one-photon absorption, multiphoton absorption only occurs around the focus point of a typical laser beam. Multiphoton absorption features both the merits of being insensitive to quenching and of being a spatially resolved technique. In a case study we assessed two-photon absorption in xenon upon exciting the 5p6 1S0-->5p56p[5/2]2 transition in xenon at a wavelength of 256 nm. The amount of light absorbed by xenon is related to the number density of the gas, and if the gas pressure is known then the gas temperature can be inferred from the number density. Two-photon absorbance was measured as a function of xenon number density and was used to validate a theoretical model of the absorption process. We discuss the circumnavigation of experimental challenges in applying this technique and analyze its precision in terms of the inferred gas temperature.     

空分设备中氪氙稀有气体提取精制技术

介绍了从大型空分设备中提取及精制氪、氙稀有气体的工艺原理和技术特点,综述了在制取氪、氙过程中如何提高过程安全性和氪、氙提取率等方面的技术进展,并对我国氪、氙稀有气体的生产现状与前景进行了概述。     

The effect of MHD interactions on the input shock waves in a supersonic diffuser

The interaction with an external magnetic field modifies the variation of the shock wave configuration in a pure inert gas plasma at the entrance of a supersonic diffuser. The phenomenon was studied using an experimental setup based on a shock tube with a flat nozzle and the model supersonic diffuser. The experiments were conducted in krypton, for the shock wave Mach number in the shock tube M=7.8 and the Mach number at the nozzle exit M=4.2. The gasodynamic discontinuities and their structural variations induced by the magnetic induction changes were by visualized by the schlieren method and by photography of the intrinsic emission accompanying the process. Three regions of the MHD interaction affecting the shock wave configuration in the gas flow were revealed.     

空分装置提高氪氙提取率的改进操作

通过对空分装置Kr/Xe提取流程的分析,结合实际操作经验提出了两项提高Kr/Xe提取率的二氪塔改进操作。     

New Data on the Solubility of Inert Gases in Liquid Alkali Metals at High Temperature

The solubility of helium, neon, argon, krypton, and xenon in molten lithium, sodium, potassium, rubidium, and cesium is calculated in the ranges of temperature from 600 to 1500 K and pressure from 0.1 to 10 MPa. The calculated data are compared, in comparable ranges of the parameters of state, with the results of the experimental investigations available in the literature of the solubility of inert gases in liquid alkali metals.