西北大学“基于新型掺钕特种光纤的高功率蓝光光纤激光器”获国家专项课题立项

我校物理系白晋涛教授主持的“基于新型掺钕特种光纤的高功率蓝光光纤激光器”课题获得了国家“十一五”863计划新材料技术领域2007年度专项课题立项，经费总额为92万元。这是我校在国家“十一五”863计划新材料技术领域获得的首项专题课题立项。     

含氮多羧酸钴(Ⅱ)-钕(Ⅲ)异核配合物合成和晶体结构

用扩散法合成了配合物[NdCo(NTA)2(H2O)11/3(CH3OH)1/3]·(CH3OH)2/3.10/3H2O(1),晶体属三斜晶系,空间群为P1,晶胞参数为a=0.963 6(2)nm,b=1.044 9(2)nm,c=1.339 3(2)nm,α=107.04°,β=98.25(2)°,γ=103.98°,V=1.217 2(4)nm3,Z=2,配合物具有三维网络结构。配合物[Nd2Co3(EDTA)3(H2O)11·12H2O](2)用水热法获得,属单斜晶系,空间群为C2,晶胞参数为a=1.592 5(3)nm,b=1.465 5(2)nm,c=1.474 1(2)nm,β=116.407(2)°,V=3.081 3(8)nm3,Z=2。每个Nd3+通过羧基桥联3个Co2+,而每个Co2+与两个相邻Nd3+连接构成12员环从而形成二维杂金属层,相邻层之间通过水的氢键作用连接形成三维结构。     

掺钕PLZT电光陶瓷的光辐射特性

研究了掺钕锆钛酸铅(PLZT)电光陶瓷的光学特性,利用Judd-O fe lt(J-O)理论计算该材料的强度参量:Ω2=0.7747×1-0 20cm2,Ω4=0.9856×1-0 20cm2,Ω6=0.9264×1-0 20cm2,并用强度参量计算了4F3/2亚稳态的辐射寿命(394μs)、受激发射截面iσj、荧光分支比,测量了4F3/2亚稳态的荧光寿命(168μs)并计算了该能级的荧光量子效率.同时还研究了该材料在803 nm激发下的上转换荧光特性.分析表明掺钕PLZT电光陶瓷在多功能器件、集成光学等方面有潜在的应用价值.     

H3BO3对SrAl2O4:Eu2+、Dy3+、Nd3+长余辉发光材料性能的影响

为了讨论H1BO3对SrAl2O4：Eu^2＋、Dy^3＋、Nd^3＋长余辉发光材料性能的影响，寻找最佳的H2BO3摩尔分数，采用燃烧法以尿素为还原剂在600℃下制备了掺入Eu^2＋、Dy^3＋、Nd^3＋的SrAl2O4长余辉发光材料．研究了不同摩尔分数的H3BO3对磷光体晶体结构、发光光谱、初始亮度和余辉性能的影响．结果表明：随着H2BO3量的增加激发和发射光谱“蓝移”，硼酸的最佳摩尔分数为0．08．可见H2BO3的含量对SrAl2O3：Eu^2＋、Dy^3＋、Nd^3＋长余辉发光材料的光学性质有很重要的影响．     

双元素掺杂纳米TiO2光催化降解亚甲基蓝的研究

以浸渍法、共沉淀法和溶胶-凝胶法制备得到了双元素钕和铁掺杂的纳米TiO2光催化剂,考察了它们对光降解亚甲基蓝的催化活性.结果表明,亚甲基蓝的光催化降解可用假一级动力学方程表示.以一定比例掺杂钕、铁离子可提高TiO2的光催化活性,尤其是在自然光下TiO2的光催化活性.在一定比例钕、铁掺杂后,共沉淀法制备的掺杂型TiO2的光催化活性接近于用溶胶-凝胶法制备的掺杂型TiO2.     

掺钕聚合物光纤的光辐射特性

制备了掺钕螯合物的聚合物阶跃型光纤.研究三价钕离子在钕螯合物掺杂的聚甲基丙烯酸甲酯(PMMA)中的吸收光谱和发射光谱.根据Judd-Ofelt理论,用吸收光谱计算钕离子在PMMA中的光学跃迁的强度参量:Ω2=33.967×10-20cm2,Ω4=4.465×10-20cm2,Ω6=3.942×10-20cm2.用该参量计算钕离子激发态(4F3/2)的辐射跃迁几率(2167.4s-1)和辐射寿命(461.4μs),同时计算了受激发射截面σij(4F3/2→4I11/2)和荧光分支比β(4F3/2→4IJ′).分析表明,Nd(DBM)3掺杂的PMMA可望用于聚合物光纤放大器和激光器.     

Scheelite Sm-Nd dating and quartz Ar-Ar dating for Woxi Au-Sb-W deposit,western Hunan

SinceFryeretal.[1](1984)firstdatedthehydrother-maldepositusingtheSm-Ndisotopemethod,thisisotopesystematicshasbeenwidelyappliedinthegeochro-nologicalstudyforhydrothermalmineralization.Inrecentyears,manyhydrothermalmineralssuchasfluorite[2—7],tourmaline[8,9],wolframite[5,10,11]andcalcite[12,13]havebeensuccessfullydatedusingtheSm-Ndgeochronometer.ScheeliteisoneofCa-bearingminerals,andrareearthelements(REE)areincorporatedinscheelitebysubstitu-tionatCa2+structuralstiesinminerallattices;moreove…     

Nd isotopic characteristics of post-Archean sediments from the Eastern Nanling Range： Evidence for crustal evolution

A systematic Sm-Nd isotopic study was carried out for sediments and metasediments of different ages from Mesoproterozoic to early Mesozoic era in southwestern Fujian, Eastern Nanling Range. The results show that Nd model age (tDM) and εNd(t) value of most sediments are closely similar to those of Paleoproterozoic Mayuan Group, indicating that they may mainly be the recycling product of Paleoproterozoic crustal materials. However, the Nd model age significantly decreases with a corresponding increase in the εNd(t) value at Neoproterozoic (ca. 0.8-0.7 Ga) and Late Paleozoic (ca. 0.25 Ga), respectively. This is manifested by prominent vales and apexes on the diagrams of tDM VS. tStr. (stratum age) and εNd(t) VS. tstr. The decrease in tDM and the increase in εNd(t) are explained as a result of the significant incorporation of juvenile crustal materials that originated from depleted mantle due to strong lithospheric extension during both periods. It appears that tectonic magmatism in the Neoproterozoic and the Late Paleozoic is of prominent importance in affecting the geochemical nature of sediments in South China.     

三(1-苯基-3-甲基-4-三氟乙酰吡唑啉酮-5)二(三苯基氧化膦)合钕(Ⅲ)——协萃络合物的合成和晶体结构

自从Jensen于1959年合成了一系列1-苯基-3-甲基-4-酰基吡唑啉酮-5以后,作为一类重要的萃取剂和位移试剂,它们已被广泛地研究和应用。我们曾合成了一系列在4-位上为卤代乙酰基的吡唑啉酮,并就它对稀土元素的萃取性能进行了研究。这类萃取剂与中性萃取剂一起具有一定的协萃性能。作为系统研究的一部分,我们合成了稀土系列的1-苯基-3-甲基-4-三氟乙酰基吡唑啉酮-5(HPMTFP)和三苯基氧化膦(Ph_3PO)的协萃络合物RE(PMTFP)_3·(Ph_3PO)_2(RE=La—Lu及Y,除Pm外),并对其中Nd(PMTFP)_3(Ph_3PO)_2的红外光谱及单晶结构进行分析研究。