N-type GaSb single crystals with high below-band gap transmission

Te-doped GaSb single crystals are studied by measuring Hall effect, infrared(IR) transmission and photoluminescence(PL) spectra. It is found that the n-type GaSb with IR transmittance can be obtained as high as 60% by the critical control of the Te-doping concentration and electrical compensation. The concentration of the native acceptor-associated defects is apparently low in the Te-doped GaSb compared with those in undoped and heavily Te-doped GaSb. The mechanism for the high IR transmittance is analyzed by considering the defect-involved optical absorption process.     

长链烷基(2-羟乙基)二甲基氯化铵用作分析增敏试剂

合成了3种含季氮原子及羟基的同系列分析增敏试剂十六烷基(2-羟乙基)二甲基氯化铵(HEMAC)、十四烷基(2-羟乙基)二甲基氯化铵(TEMAC)和十二烷基(2-羟乙基)二甲基氯化铵(DEMAC),测试其基本物性,并用作测定微量钪、铁(Ⅲ)、锗的增敏试剂,获得了与阳离子表面活性剂及醇类有机溶剂联用时相仿的增敏效果。     

用氢化物—原子荧光法测定水处理剂中微量铅

对氢化物－原子荧光法测定水处理剂聚合氯化铝和硫酸铝中铅的测定介质、测定条件及干扰元素进行了探讨,拟定了简便,快速,准确测定两种水处理剂中微量铅的方法。在测定条件下,方法的线性范围为０￣５０ｎｇ·ｍｌ＾－１,检出限为０．４ｎｇ·ｍｌ＾－１,回收率在９０％￣１１０％之间。     

贝塞尔光束在生物医学显微成像技术中的应用（特邀）

作为一种典型的无衍射光束,贝塞尔光束具有无衍射和自重构特性,能够提供更长的聚焦长度和一定程度的抗散射能力,在生物医学光学显微成像技术领域获得了越来越多的应用。本文重点关注了贝塞尔光束在生物医学光学显微成像技术中的应用,包括利用其扩展景深能力实现体积样本快速三维成像、利用其抗散射粒子干扰能力实现散射样本的大深度成像以及利用更细聚焦光束能力实现更高分辨率的光学显微成像。首先,概述了贝塞尔光束及其实验室常用的产生方法;然后,总结了近些年贝塞尔光束在生物医学光学显微成像技术中的应用,包括但不限于多光子荧光显微成像、光片荧光显微成像、拉曼显微成像等,既总结了贝塞尔光束在其中发挥的优势,也分析了贝塞尔光束旁瓣带来的干扰问题的消除方案。最后分析和探讨了贝塞尔光束在生物医学光学显微成像技术应用中遇到的问题以及发展前景。     

INVESTIGATION OF THE EFFECT OF SLOW NEUTRON IRRADIATION ON HALOGEN-DOPED HIGH-Tc SUPERCONDUCTORS AND ITS MECHANISM

Irradiation effect of low-fluence (-10⁸ n/cm² ) slow neutrons on halogen-doped superconductors is presented in this paper. And the mechanism of the effect is also described from the viewpoint of nuclear physics for both fast and slow neutrons on high-temperature superconductors (HTSC). It is shown ex-perimentally and theoretically that slow neutrons of low fluence has a similar irradiation effect to that of fast neutron beams with an energy E_n>0.1 MeV and fluence 10¹⁶-10¹⁸ n/cm²-However,quite differ-ent mechanisms are involved in them: Fast neutrons transfer their energies through elastic scattering in HTSC, whereas slow neutrons give off their energies during the slow neutron capture (n,γ) reaction.     

石墨炉原子吸收光谱法测定水处理剂中微量铅和镉

本文研究了石墨炉原子吸收光谱法测定水处理剂聚合氯化铝中铅、镉含量的适宜条件。用氘灯校正背景 ,磷酸二氢铵做基体改进剂 ,省去了冗长的前处理过程。在测定条件下 ,铅的检测限为 0 .6 5μg· L- 1 ,线性范围 0～ 5 0 μg·L- 1 ;镉的检测限为 0 .12 μg· L- 1 ,线性范围 0～ 2 0 μg·L- 1 ;回收率在 90 %～ 110 %之间。本方法具有准确、快速、简便之优点 ,用于实验样品的测定 ,结果令人满意。     

低通量慢中子辐照对高Tc超导体正常态电阻的影响及其机理探讨

研究了低通量(～10⁸n/cm²)慢中子对Y系、Bi系及其掺杂高T_c超导体(HTSC)正常态电阻的影响及其机理。实验结果表明,HTSC在低通量慢中子辐照后,正常态电阻R不仅不遵从随辐照通量φ_n按指数增加的规律,而且还会较大幅度地减小。 关键词：