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。     

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。     

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。     

Microwave-assisted Solvothermal Synthesis of YF3 ： Yb^3＋, Tm^3＋ Nanobundles

Recently, considerable attention has been paid to the synthesis and research of various rare-earth （RE） doped fluoride nanomaterials because of their high refractive index and appropriate phonon energy, which have potential applications in optics, optoelectronics, microelectronics, and tribology. Many methods have been utilized to synthesize the nanomaterials of RE doped fluorides with controllable sizes, shapes, and nanostructures. Comparatively, the microwave irradiation （MWI） method is simple, fast, and unique in its potential for large-scale synthesis without suffering thermal gradient effects.     

Yb^3＋对Tm^3＋间接敏化与基质晶格关系

Yb^3 敏化Tm^3 有两种方式,一种是直接敏化上转换,另一种是间接敏化上转换。前种直接采用980nm激光激发,而后者可用807nm激光激发,无疑后者有利于提高上转换发光的量子效率。由于基质晶格的晶体场强度不同,对称性有高有低,造成的稀土离子的能级分裂不同,通过分析双掺BaY2F8,Cs3Yb2C19等材料的光谱资料并结合生长的双掺Yb^3 ,Tm^3 :ZnWO4单晶光谱的实际测试与分析,提出了Yb^3 和Tm^3 间的间接敏化共振能量传输的新观点,并具体分析了能形成这一上转换机制的条件。与间接敏化非共振能量传输不同,一是Yb^3 的^2F5/2→^2F7/2的跃迁应与Tm^3 3H4→^1G4能级间隔尽可能接近;二是Yb^3 激发态能级^2F5/2与Tm^3 的^3H4能级尽可能接近。这要求基质材料的晶体场场强要弱,对称性要低。间接敏化共振能量传输极有可能引起光子雪崩上转换,这将为探索实用上转换激光晶体提供有益经验。     

Preparation and Luminescence Behavior of CaSiO3：Eu^3＋（Bi^3＋）

CaSiO3：Eu0.08^3＋Bi0.002^3＋ with a monoclinic perovskite structure was synthesized by using sol-gel method, and its luminescence characteristics were investigated. From the excitation spectrum, it can be seen that the main peaks located at 238,396,415,437 and 359 nm correspond to the charge-transfer band of Eu^3＋-O^2- , the absorption transitions of ^7F0.1→^3L6, ^7F0→^5D3, ^7F1→^5D3 of Eu^3＋ ions, and ^3P1→^1S0 of Bi^3＋ ions, respectively. When the samples were excited with a light of wavelength 359 or 395 nm, it can be seen from the emission spectrum that the electronic dipole transition located at 609 nm corresponding to ^5D0→^7F2 of Eu^3＋ ions was stronger than the magnetic dipole transition located at 587 nm corresponding to ^5D0→^7F1 of Eu^3＋ ions, which shows that more Eu^3＋ ions were located in nonreversion center lattices. The energy transfer from Bi^3＋ ions to Eu^3＋ ions in the phosphor was also discussed. The results show that Eu^3＋ ions could be well sensitized by ^3＋ions, and the energy-transfer pattern between Bi^3＋ ions and Eu^3＋ ions was resonance energy transfer.     

Ca3La3（BO3）5中Ce^3＋,Pb^2＋,Mn^2＋的光致发光和能量传递

本文研究了Ca_3La_3(BO_3)_5体系中Ce~(3+)、Pb~(2+)、Mn~(2+)光致发光与组成的关系及Ce~(3+)、Pb~(2+)对Mn~(2+)发光的敏化作用。实验表明在254nm激发下,Ce~(3+)、Pb~(2+)均在紫外光区发光,而单激活的Mn~(2+)几乎不发光。Ce~(3+)、Pb~(2+)能敏化Mn~(2+)发光,且Ce~(3+)的敏化作用比Pb~(2+)强。Ce~(3+)-Mn~(2+)共激活的Ca_3La_3(BO_3)_5在紫外光激发下发出明亮的红光。Ce~(3+)-Mn~(2+)能量传递的机理为电多极相互作用的共振传递。     

Ca1—xZnxTiO3：Pr^3＋,R^＋（R^＋=Li^＋,Na^＋,K^＋,Rb^＋,Cs^＋,Ag^＋）的合成和发光性质

采用X射线衍射、荧光光谱和热释发光研究了Ca1-xZnxTiO 3∶Pr3+, R+的物相组成和发光性质. Pr3+取代Ca2+形成PrCa ·正电性缺陷发光中心. 激发光谱是峰值位于330 nm附近的宽带谱, 发射光谱是峰值在613 nm半宽度为20 nm的带谱, 对应Pr3+的1D2-3H4跃迁发射. 发光强度和余辉随基质组分Zn/Ca摩尔比和合成温度而变化. Zn2+的最佳含量在10%～20%. X射线衍射研究表明掺入适量的Zn2+物相组成为CaTiO3, Ca2 Zn4Ti15O36和Zn2TiO4. 热释发光曲线表明掺入Zn2+离子后体系中形成了新的缺陷ZnTi″, 且ZnTi″的缺陷陷阱深度大于RCa′.     

二—（2,4,4—三甲基戊基）膦酸浸渍树脂分离Tb^3＋,Dy^3＋,Ho^3＋,Er^3＋的研究

研究了大孔风状树脂ＸＡＤ－Ｒ,ＸＡＤ－７,ＸＡＤ－１１８０对二－（２,４,４－三甲基戊基）膦酸浸渍树脂的吸附及制备方法,并对Ｃｙａｎｅｘ５７１浸渍树脂分离稀土的性能进行了研究,发现在盐酸介质中Ｃｙａｎｅｘ５７１／ＸＡＤ－７具有最强的萃取能力,树脂中的萃取剂含量在０．３５－０．４５ｇ．ｇ＾－１时,其萃取性能最好,将上述浸渍树装入色层柱对稀土元素进行了分离,且降低负载量和流速分离效果量好。     

Pr3＋或La3＋与克拉红霉素对大肠杆菌的协同作用

用LKB-2277生物活性检测系统采用停流法于37 ℃测定了克拉红霉素及克拉红霉素分别与Pr(NO3)3和La(NO3)3混合后,对大肠杆菌生长抑制作用的热效应变化.根据热动力学模型进行了定量解析,得到了各体系的克拉红霉素浓度c与大肠杆菌生长速率常数k之间关系式及其半抑制浓度Ic50. 克拉红霉素:　　 k=0.03106－1.273×10－3c　Ic50=8.81 μg•mL－1　　(0.5～20 μg•mL－1) 克拉红霉素＋Pr3＋: k=0.02967－1.332×10－3c Ic50=7.38 μg•mL－1　　 (1～15 μg•mL－1) 克拉红霉素＋La3＋: k=0.02741－1.194×10－3c　Ic50=6.34 μg•mL－1　 (1～15 μg•mL－1) 微量热结果不仅表征了克拉红霉素的抗菌活性强于红霉素,Pr3＋或La3＋与克拉红霉素协同作用也使抗菌活性增强,而且反映了不同药物作用下细菌的生理、生化和代谢过程热动力学特征的变化.     

Defects in Tm^3＋／Yb3＋—doped YVO4 Crystals

<正>The microscopic defects have been investigated for crystal Tm3+/Yb3+:YVO4. These defects mainly include the inclusions (solid inclusions, bubbles and inclusions of the liquid phase), dendrites and growth stripes. They are caused by in-pure raw materials, unstable growth conditions, super-cooling component and so on. Tm3+/Yb3+:YVO4 crystals of large size and excellent optical quality are grown by improving the growth conditions to eliminate these defects.     

Tb^3＋和Dy^3＋共激活的LaOBr阴极射线发光特性

固体发光材料中,稀土离子间的光学性质和能量传递已作了大量工作。但是,在阴极射线(CR)激发下,稀土离子间相互作用和发光性质的变化,特别是有关能量传递还很少报道。LaOBr:Tb~(3 )和LaOBr:Tm~(3 )是一类高效的阴极射线发光和X射线增感屏用荧光粉,人们曾对LaOBr:Ce~(3 ),Tb~(3 )的发光性质进行了研究,本文则获得了     

Ce^3＋—Gd^3＋在某些稀土硼酸盐体系中的能量传递

Ce~(3 )离子有一个宽而强的4f-5d吸收带,它能有效地吸收能量。Ce~(3 )离子的荧光寿命非常短,能将能量有效地传递给其它离子起敏化作用。对于Ce~(3 )→Tb~3 ),Ce~(3 )→EU~(3 )和Ce~(2 )→Mn~(3 )的敏化作用已有许多报导,并在灯用发光材料上获得应用。Blasse等提出在Ce~(3 )敏化Tb~(3 )时。用Gd~(3 )作中间体能获得高效发光材料。由于Ce~(3 )的5d能级强烈地依赖于基质,其发射波长可以从紫外到红区,而Gd~(3 )的4f-4f跃迁的激发和发射峰值随基质的变化改变不大,因此将有可能呈现不同的Ce~(3 )-Gd~(3 )的能量转移过程。     

GdF3∶Er^3＋,Yb^3＋的合成和上转换发光特性

采用水热法制备了Er^3＋离子浓度为3%,Yb^3＋离子浓度分别为10%,20%的GdF3∶Er^3＋,Yb^3＋。XRD结果表明：合成的样品均为正交结构的GdF3,Gd0.87Yb0.10Er0.03F3和Gd0.77Yb0.20Er0.03F3样品的晶粒尺寸分别为28和26nm。研究了980nm红外光激发的上转换发射光谱。结果表明：红光和绿光发射分别来自于Er^3＋离子的2H11/2,4S3/2→4I15/2和4F9/2→4I15/2跃迁。样品的绿光发射强度较红光发射强。但绿光和红光发射的相对强度比例与Yb^3＋离子浓度有关。对Gd0.87Yb0.10Er0.03F3和Gd0.77Yb0.20Er0.03F3样品中可能的上转换发光机制进行了讨论。     

^3A＇ and ^3A＂ Energy Surfaces for the VS^＋ ＋ CO2→VO^＋ ＋ COS Reaction

The title reaction proceeds via a one- and two-step mechanism along the ^3A＂ and ^3A＇ surfaces, respectively. The ^3A＇ excited state surface has a lower barrier than the ^3A＂ ground state surface （11.6 and 16.0 kca1/mol, respectively）, We suggest that, at low energies, the reaction proceeds along the A＇ surface and then makes an intersystem crossing to the A＂ surface and yields the ground state product VO^＋（^3∑^-）, which may explain the small VO^＋ cross-section at low energies observed in the experiment     

Tb^3＋和La^3＋与牛血清白蛋白作用的光谱研究

Ｔｂ～（３＋）和Ｌａ～（３＋）与牛血清白蛋白作用的光谱研究冯志祥，张树功，刘启民，倪嘉缵（中国科学院长春应用化学研究所稀土化学与物理开放实验室长春１３００２２）苗健，油书恒（河南医科大学生化教研室郑州）关键词镧离子，铽离子，牛血清白蛋白，光谱法血清白...