LaBO3中Ce^3＋,Dy^3＋的发光和能量传递

研究了在紫外线、阴极射线和X射线激发下,Ce~(3 ),Dy~(3 )单掺杂或共掺杂的LaBO_3的发射光谱、激发光谱和其发光强度随组成变化的规律。在紫外线激发下,Ce~(3 )可很好地敏化Dy~(3 )的发光,而在后两种激发下,Ce~(3 )则明显地猝灭Dy~(3 )的发光。研究了在352nm激发下,Dy~(3 )发光强度与浓度的关系,证明Dy~(3 )自身浓度猝灭的机理是电偶极-偶极相互作用。Ce~(3 )→Dy~(3 )能最传递的机理是电多极相互作用为主的共振传递。     

Growth and Spectral Properties of Yb^3＋-doped Ba3Gd（BO3）3 Crystal

Crystal of Yb3+-doped Ba3Gd(BO3)3 has been grown by the Czochralski method. The spectroscopic characterizations have been investigated at room temperature. The Yb3+:Ba3Gd(BO3)3 crystal exhibits broad absorption at 976nm with FWHM of 7nm and large overall spitting of 2F7/2 manifold (823cm-1). The absorption and emission cross sections are 5.09×10-21cm2 at 976nm and 0.97×10-21cm2 at 1040nm,respectively. The fluorescence lifetime is 2.84 ms.     

掺杂B^3＋在SrA12O4：Eu，Dy中的作用及其机制研究

研究了H38O3在碱土铝酸盐长余辉发光材料中的作用，发现H38O3不但影响固相反应速度，还对粉体晶相组成、粒径以及长余辉发光性能产生很大的影响。TG—DTA，XRD和SEM分析表明，H3803参与了固相反应，降低了成核温度与界面反应能垒，使晶粒生长反应速度加快，粉体粒径增大。激发与发射光谱、发射峰强度衰减以及热释光谱分析表明，H3BO3的掺人使发光中心离子浓度增加、陷阱深度和密度加大，从而使发光亮度增加，余辉寿命延长。     

Growth and Characteristics of Nd^3＋：GdAl3（BO3）4 Crystal

Nd^3 :GdAl3(BO3)4(NGAB) crystal with the size of 30 mm was grown from the solvent system of K2O-Gd2O3-MoO3-B2O3 by combining accelerated seed rotation technology with medium seeded solution growth (MSSG) method,and its crystal structure has been determined by X-ray powder diffraction.It crystallizes in the trigonal system,space group R32 with a=9.2743(2),c=7.2438(1)A,V=538A^3,Z=3and Dc=4.379g/cm^3,The absorption and emission spectra of NGAB in the function of σ and π polarizations at room temperature have been measured.UV generation tuneable in 378-382nm,green(531nm) generation and blue generation tuneable in 436-443 nm as well as red(669)nm generation by self-frequency changing were obtained with the oupput of 105, 119.5,445and 19μJ/pulse,respectively,when the crystal was pumped by a dye laser.     

THE STRUCTURE OF A NEW LASER CRYSTAL—Nd^3＋：Li6Y（BO3）3（NLYB）

<正> The crystal structure of Nd3+: Li6Y(BO3)3 is monoclinic, belonging to space group P21/c with the following cell constants:a =7. 157(5),b=16. 378(8),c = 6. 623(4)A.B=105. 32(5) ,Z=4,F =748. 8A3,Dc=2.747g/cm3. Mr (Li6Nd0.027 Y0.973(BO3)3) = 308. 47. The structure unit Li6Y(BO3)3 contains three B-O triangle planes,a distorted Y-O tetragonal prism,and five distorted Li-O trigonal bipyramids and one Li-O tetrahedron.     

Growth and Characterization of γ—Nd^3＋：LaSc3（BO3）4Crystal

INTRODUCTIONLaser-diode(LD) pumped solid-state lasers have a variety of applications in the fields of military, industry, medical treatment and scientific researches due to the advantages of high stability, compactness, high efficiency and long lifetime, and this area has become one of the hot points in the laser field. As a result, research on new materials with improved spectral properties for diode pumping is of increasing interest again. A new high efficient diode-laser-pumped solid-s…     

石墨负极在Et4NBF4＋LiPF6/EC＋PC＋DMC电解液中的电化学行为

在PC+EC+DMC复合溶剂体系中,研究了Et4NBF4(四氟硼酸四乙基铵)与LiPF6组成的复合盐电解质对石墨负极材料界面性质的影响.用循环伏安和恒电流充放电测试方法研究了电解液与石墨负极的相容性,通过傅里叶变换红外光谱(FTIR)对固体电解质中间相膜(SEI)的成分变化进行了研究.结果表明,电解液中的Et4NBF4参与了SEI膜的形成;当Et4NBF4浓度为0.2和0.5mol·L-1时,电池首次充放电不可逆容量损失明显减少,循环效率分别七升到76.O%和81.6%.Et4NBF4/LiPF6复合盐电解质改善了PC基电解质与石墨负极的相容性.     

CO(NH2)2-H3BO3-H2O体系相平衡研究

农作物不仅需要吸收C、H、O、N、P、K、Ca、Mg等营养元素,而且还需要吸收B、Mn、Zn等营养元素,以维持它们正常生长的需要.尿素是一种含氮量很高(46.60%)、性能很好的氮肥,而硼化合物又是一种很重要的微量元素肥料.因此,研究尿素与硼化合物间的相互作用,以得到既含氮又含硼的一种化合物,是一种很有意义的工作。目前,国外已开展了尿素与硼酸间相互作用的研究工作.研究结果表明,在一定条     

硼酸盐水溶液热力学研究II: H3BO3-LB(OH)4-LiCl-MgCl2体系

在278.15～318.15K下, 测定了无液电池(A), Pt, H2│B(OH)3(m1),LiB(OH)4(m)2, LiCl(m3), MgCl2(m4)│AgCl, Ag和电池(B), Pt, H2│B(OH)3(m1), LiB(OH)4(m2), MgCl2(m4)│AgCl, Ag的电动势。利用Debye-Huckel外推法和多项式拟合法确定了硼酸镁离子对[MgB(OH)4^+缔合常数pKt, 并得到了经验方程pKt=A1+A2/T+A3T以及缔合过程的其他各标准热力学量, 同时指出缔合熵是形成[MgB(OH)4^+]离子对的推动力。     

硼酸盐水溶液热力学研究II: H3BO3-LB(OH)4-LiCl-MgCl2体系

在278.15～318.15K下, 测定了无液电池(A), Pt, H2│B(OH)3(m1),LiB(OH)4(m)2, LiCl(m3), MgCl2(m4)│AgCl, Ag和电池(B), Pt, H2│B(OH)3(m1), LiB(OH)4(m2), MgCl2(m4)│AgCl, Ag的电动势。利用Debye-Huckel外推法和多项式拟合法确定了硼酸镁离子对[MgB(OH)4^+缔合常数pKt, 并得到了经验方程pKt=A1+A2/T+A3T以及缔合过程的其他各标准热力学量, 同时指出缔合熵是形成[MgB(OH)4^+]离子对的推动力。     

Na~＋，K~＋‖Cl~－，B_4O_7~（－2）－H_2O四元体系25℃时相平衡研究

Ｎａ~＋，Ｋ~＋‖Ｃｌ~－，Ｂ_４Ｏ_７~（－２）－Ｈ_２Ｏ四元体系２５℃时相平衡研究阎树旺，唐明林，邓天龙（成都理工学院液态矿产综合利用研究室成都，６１００５９）关键词四硼酸钠，四硼酸钾，相平衡，卤水近年来，在四川盆地成都凹陷平落坝地区发现了富硼、钾、低?..     

硼酸盐玻璃中Gd^3＋,Dy^3＋,Bi^3＋对Tb^3＋发光性质的影响

本文研究了单掺和双掺(Tb~(3+)、Tb~(3+)+Gd~(3+)、Tb~(3+)+Dy~(3+)、Tb~(3+)+Bi~(3+)约四十余种不同成份的硼酸盐玻璃。探讨了玻璃成份对Tb~(3+)发光性质的影响和Gd~(3+)、Dy~(3+)、Bj~(3+)对Tb~(3+)的胜化作用。在B_2O_2-BaO-M_mO_n(M_mO_n=Li_2O、Na_2O、K_2O、MgO、CaO、SrO、Al_2O_3、La_2O_3和Bi_2O_3)玻璃体系中,当M_mO_n分别为MgO和Al_2O_3时,Tb~(3+)的发光强度最强;M_mO-n为Bi_2O_3时,Tb~(3+)的发光强度最弱。Tb~(3+)的特征发射峰分别随着碱金属、碱土金属和三价金属的离子半径增加而红移。Gd~(3+)、Dy~(3+)、Bi~(3+)对Tb~(3+)均有敏化作用。特别是Gd~(3+),使Tb~(3+)的发光强度增加1～3.8倍,其最佳敏化浓度,因基质玻璃成份而异。     

三元体系H3BO3-MgCl2-H2O在308.15K和323.15K稳定相平衡研究

采用等温溶解法研究了三元体系H3BO3 - MgCl2 - H2O在308.15 K和323.15 K的稳定相平衡;测定了上述体系液相中各组分的平衡溶解度及液相密度,并绘制了相应相图和平衡溶液密度组成图.结果表明,该体系在308.15 K和323.15 K时有一个共饱点、两条饱和溶解度曲线和两个结晶相区,无复盐及固溶体...     

Structure of Low Temperature Phase β—Ba3Y（BO3）3 Crystal

Crystals of the low temperature phase β-Ba3Y(BO3)3 have been synthesized by the flux method. The structure of the title compound crystallizes in the hexagonal system, space group P63cm with the following parameters: a = 9.416(3), c = 17.536(8) A, V= 1346.6(8) A3, Ba3YB3Og,Mr = 677.36, Z = 6, Dc = 5.012 g/cm3, λ(MoKα) = 0.71073 A,μ = 19.409 mm- 1, Flack parameter =0.02(3), F(000) = 1764, R = 0.0714 and wR = 0.1696 for 1076 observed reflections with Ⅰ＞ 2σ(Ⅰ).The compound contains two sets of YO6 octahedra, four sets of BaO9 polyhedra and three sets of BO3 planar triangles.     

MgSO4-H3BO3-H2O体系水热条件下结晶动力学

自然界中硼铁矿属于多元素(Ｆｅ、Ｂ、Ｍｇ)共生矿,使用价值很高,是我国未来硼资源的主要来源.根据我国硼铁矿品位低的特点,东北大学提出了硼铁矿高炉铁硼分离生产含硼生铁及富硼渣、富硼渣硫酸浸出一步法生产硼酸的火法工艺路线[1],矿石中的镁以硫酸镁的形式存在于母液中.母液经浓缩、过滤,主要成分为硫酸镁和硼酸水溶液,母液中硫酸镁和硼酸分离是目前急需解决的问题.当温度高于80℃时,硫酸镁在水中的溶解度随温度的升高而降低,硼酸的溶解度随温度的升高而增加[2].根据硫酸镁和硼酸的溶解度特点,在常温下将两者分离是不可能的,通过高温结晶…     

Optical-transition Probability of Tm^3＋ Ions in Tm^3＋／Er^3＋：YVO4 Crystal

1INTRODUCTIONThelasersoperatedataround2mmwavelengthhavegainedmuchinterestbecauseofvariousappli-cations,e.g.(1)groundorspaceremotesensingforLIDARandmetrology,(2)medicalapplicationssinceliquidwaterhasastrongabsorptionbandnear2mm,and(3)eyesafelaser[1,2].The2…     

KZnF3中Ce^3＋→Eu^2＋的能量传递

研究了ＫＺｎＦ３中Ｃｅ＾２＋和Ｅｕ＾２＋的光谱特性,在共掺Ｃｅ＾３＋和Ｅｕ＾２＋的体系中,观察到了Ｃｅ＾３＋对Ｅｕ＾２＋的能量传递过程,计算了能量传递的量子效率,探讨了能量传递机理,研究发现,Ｃｅ＾３＋的存在有利于Ｅｕ＾２＋的ｆ－ｆ跃迁线状发射。     

MgSO4-H3BO3-H2O体系水热条件下结晶动力学

The solution of MgSO4-H3BO3-H2O system containing 20%(mass fraction)MgSO4 and 2.5% H 3BO 3 was prepared and the experimental study of its crystallization at 180℃ were carried out in a high pressured vessel. Only a solid phase MgSO4•H2O was separated out from the system. The experimetal data were fitted. With the aid of simplex optimum method and Runge-Kutta digital solution of a set of differential equations, Single-nuclear interface reaction model (MB2) was selected to describe the process of crystallization of kieserite. the dynamic equation is as follows:
-dc/dt=0.064(2.24-c) 4/3 (c-0.290)2