分类: 物理学 >> 凝聚态:结构、力学和热性能 提交时间: 2017-03-26
摘要: Two cryogenic systems of high purity germanium detector, liquid nitrogen and mechanical coolers, are expound, together with explanations of merits and demerits for each kind of cooling methods. The resolutions of detector to the characteristic lines of 152Eu under different cooling conditions are studied. The laboratory results indicate that the mechanical cooler (X-Cooler II) is an ideal replacement candidate for the liquid nitrogen cooler that is being utilized by BEMS at BEPC-II.
分类: 核科学技术 >> 核材料与工艺技术 提交时间: 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要: Amino-type adsorbents (ATAs) were prepared by radiation-induced graft copolymerization of 4-hydroxybutyl acrylate glycidyl ether (HB) onto a polyethylene-coated polypropylene (PE/PP) duplex fiber of a non-woven fabric, and modified with different amines of ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetetramine (TETA) and diethylamine (DEA). The adsorption behavior of uranyl ions onto the ATAs was studied in batch experiments. The effects of the contact time, initial concentration of the ions, temperature, and pH value. The salinity were investigated along with the adsorption kinetics and the adsorption isotherms. The kinetic experimental data followed the pseudo second-order kinetic model, and the adsorption isotherms correlated well with the Langmuir model. The ATAs showed good efficiency in adsorbing uranyl ions, with the best saturation adsorption capacity being 64.26 mg g-1 for ATA-DETA within 120 min. The temperature dependence of ATA-DETA was quite abnormal and the quickest behavior was obtained at 25 ℃. ATAs showed good adsorption capacity over a wide pH range of 4.08.5, and HCl could be used in the elution process. Salinity of the solution had great effect on the adsorption capacity, 3.5% salinity resulted in a 55% loss of capacity from ATA-DETA. The selectivity of ATA-DETA showed an order of: UO22+ Fe3+ > Zn2+ > VO3- > Co2+ > Ni2+.