Watt-level Pr^3+:YLF deep red laser pumped by a fiber-coupled blue LD module or a single-emitter blue LD

A power-scaled laser operation of Pr:YLi F4(YLF)crystal at 720.9 nm pumped by a 443.6 nm laser diode(LD)module was demonstrated.The 20 W module was used to pump the Pr:YLF crystal,and a maximum output power of 3.03 W with slope efficiency of 30.04%was obtained.In addition,a 5 W blue LD was also used to pump the Pr:YLF laser,and a maximum output power of 0.72 W was obtained at room temperature.The output power was limited by the wavelength mismatch between the single-emitter LD and the absorption peak of the crystal.     

中微双孔分子筛Beta-MCM-41的微波合成及加氢脱硫性能研究

以四乙基氢氧化铵(TEAOH)为微孔模板剂,十六烷基三甲基溴化铵(CTAB)为介孔模板剂,SiO2、Fumed Silica或TEOS为硅源,通过微波两步自组装合成Beta-MCM-41型中微双孔分子筛。然后以合成的Beta-MCM-41(BM-S-M)、实验室自制的Beta、MCM-41、SBA-15以及γ-Al2O3为载体,通过等体积浸渍15%MoO3,3%NiO和3%CoO,制备得到Co-Mo-Ni-BM-S-M等氧化物催化剂;并在间歇式高温高压反应釜中,在350℃、5.0MPa H2压力下,以二苯并噻吩(DBT)为模拟油品研究所制备催化剂的加氢脱硫性能及反应动力学。结果表明,SiO2为硅源,微波辐射合成的BM-S-M分子筛结构有序性更好,比表面积(1033.923m2/g)和孔容(0.729cm3/g)更大,孔径集中分布在3.08nm(中孔)和1.22nm(微孔),且具有较强的酸性中心。4种不同载体催化剂的DBT加氢脱硫活性顺序为Co-Mo-Ni-BM-S-M>Co-Mo-Ni-MCM-41>商业Co-Mo-Al2O3>Co-Mo-Ni-Beta。此外,4种不同载体催化剂的加氢脱硫过程符合拟一级动力学规律。