稀土正硼酸盐Ln1-xBO3:Eux(Ln=Y,Gd)的结构与发光特性

用溶胶－凝胶法和高温固相反应分别制备了纳米量级和常规尺度的稀土正硼酸盐荧光粉ＬnBO3:3n(Ln=Y,Gd),测量了它们的激发光谱并首次观察到了ＹＢＯ３：Ｅu中Ｅu^3 的^7F0→^5D0跃迁的Nephelauxetic效应。根据低温下的激发光谱,发射光谱以及变温条件对发光光谱的影响,ＹＢＯ３中Ｌn^3＋所占据的两种格位的对称性被修正为Ｃ３和Ｄ３。在不同方法制备的样品中观察到了不同的发光强度和猝灭浓度。缺陷的影响是产生这种不同的原因,退火样品的发光和拉曼散射谱的变化反映出掺杂的杂质Eu^3 的团聚化是可能的缺陷来源。     

PDP荧光粉GdBO_3:Eu格位选择激发下的光致发光及其相变研究

用溶胶－凝胶法制备了ＰＤＰ用荧光粉ＬＴ－ＧｄＢＯ３：Ｅｕ,并用常规的手段,包括ＸＲＤ、拉曼散射谱、发光光谱等研究了它的晶体结构和光谱性质．利用染料激光系统,选择激发荧光粉中不同格位上 Ｅｕ３＋的５Ｄ０能级,得到了对应于不同格位的两套发射谱,并根据发射谱分析了Ｅｕ３＋的格位对称性,以及对这两种格位之间的能量传递过程产生影响的一些因素．在１０００～１１００℃之间,发生了ＬＴ－ＧｄＢＯ３向另一种Ｖａｔｅｒｉｔｅ结构的ＧｄＢＯ３的相转变．相变的过程伴随着因ＧｄＢＯ３晶体结构发生重排而引起的热吸收．荧光粉ＬＴ－ＧｄＢＯ３：Ｅ３有很高的亮度,同时其猝灭浓度高达 ２０ｍｏｌ％．     

Y2O3：Eu超微粉末的合成及发光性质研究

本文用络合－沉淀法制备了Ｙ２Ｏ３：Ｅｕ超微粉末，平均粒径０．０４μｍ－０．１μｍ，ＸＲＤ分析为立方晶系，试验结果表明，Ｙ２Ｏ３：Ｅｕ的平均粒径和相对亮率随焙烧温度的增加而明显增加；超微状态下的Ｙ２Ｏ３：Ｅｕ相对亮度低；Ｙ２Ｏ３：Ｅｕ的平均粒径对相对亮度有很大的影响。     

（Y，Zn，Sr）_3（P，VO_4）_2：Eu~（3＋），Bi~（3＋）发光性

合成了组成为（Ｙ，Ｚｎ，Ｓｒ）３（Ｐ，ＶＯ４）２：Ｅｕ３＋，Ｂｉ３＋的荧光材料，经射线结构分析确定为Ｚｎ３（ＰＯ４）２结构，属于单斜晶系，空间群为Ｐ２１／ｎ讨论了基质组成对Ｅｕ３＋离子发光性质的影响，用Ｙ３＋取代了一部分Ｚｎ２＋，用ＶＯ取代了一部分ＰＯ．由于基质的４３６ｎｍ发射与Ｅｕ３＋的激发态能级的能量重叠，Ｅｕ３＋产生较强的５９８ｎｍ和６１８ｎｍ发射．另外，掺入少量Ｂｉ３＋能增强Ｅｕ３＋发射．     

高温高压合成的硅酸锶铕铋的发光特性

用高温高压方法合成了Ｓｒ２ＳｉＯ４：Ｅ３＋ｕ，Ｂｉ３＋和ＳｒＳｉＯ３：Ｅｕ３＋，Ｂｉ３＋研究了合成压力对其发光性能的影响，与用溶胶－凝胶共沉淀法和常压高温法合成的产品作比较．常压制备的ＳｒＳｉＯ３：Ｅｕ３＋，Ｂｉ３＋为六角结构，而在２．３４—４．１０ＧＰＳ的合成压力范围内，它转变为反正交结构；常压下Ｓｒ２ＳｉＯ４：Ｅｕ３＋，Ｂｉ３＋为单斜结构，在４．２ＧＰａ的合成压力下，未发现其结构相变．高压合成产物的发光强度和相对量子发光效率降低，半宽度明显增加，且伴有红移发生．发光强度的改变是压致晶场的变化引起的     

BaFCl：Eu^2＋,Eu^3＋的光激励发光过程

本文首次报道了ＢａＦＣｌ：Ｅｕ＾２＋,Ｅｕ＾３＋的光激励发光。实验结果发现,在ＢａＦＣｌ：Ｅｕ中Ｅｕ＾３＋对Ｅｕ＾２＋的光激励发光有增强作用。在ＢａＦＣｌ：Ｅｕ的光致发射光谱中同时观察到对Ｅｕ＾２＋、Ｅｕ＾３＋及基质的本征发射,而光激励发射光谱中只观察到Ｅｕ＾２＋的发射,表明光致发光与光激励发光存在着很大的差异。这些结果表明,发光中心Ｅｕ＾２＋、Ｅｕ＾３＋及基质之间存在着相互作用和能量传递。本文提     

纳米YSZ∶Eu~(3+)粉末的制备及光谱研究

本文用化学共沉淀法制备出掺Ｅｕ３＋离子的Ｙ２Ｏ３稳定的纳米立方相ＺｒＯ２粉末，并在不同温度下烧结获得不同晶粒度的粉末，分别用Ｘ射线及ＴＥＭ对粉末的晶粒度进行了分析。通过对不同晶粒度的样品进行激发谱和荧光谱的研究表明，随晶粒度减小，ＹＳＺ∶Ｅｕ３＋的激发谱峰位有红移现象，其荧光谱的５Ｄ０→７Ｆ２跃迁有明显变化，而且各跃迁的强度比也有改变。文章从晶格变化及纳米材料的特殊表面结构等方面对光谱的变化进行了解释。     

用溶胶—凝胶法制备的Y2SiO5：Gd,Eu荧光粉的发光性能

用溶胶－凝胶法合成了Ｙ２ＳｉＯ５：Ｇｄ,Ｅｕ红色荧光粉。探讨了烧结工艺对粉体的结构及发光性能的影响。首次报道了搀杂Ｇｄ的Ｙ２ＳｉＯ５：Ｅｕ红色荧光粉的发光性能。研究结果表明,搀杂适当浓度的Ｇｄ,可以显著提高ＹｓＳｉＯ５：Ｅｕ红色荧光粉的发光强度,在Ｙ２ＳｉＯ５基质中,Ｇｄ＾３＋是Ｅｕ＾３＋的优良敏化剂。     

（Y,Zn,Sr）3（P,VO4）：Eu^3＋,Bi^3＋发光性质的研究

合成了组成为（Ｙ，Ｚｎ，Ｓｒ）３（Ｐ，ＶＯ４）：Ｅｕ＾３＋，Ｂｉ＾３＋的荧光材料，经Ｘ射线结构分析确定为Ｚｎ３（ＰＯ４）２结构，属于单斜晶系，空间群为Ｐ２１／ｎ。讨论了基质组成对Ｅｕ＾３＋离子发光性质的影响，用Ｙ＾３＋取代了一部分Ｚｎ＾２＋；用ＶＯ４取代了一部分ＰＯ４由于基质的４３６ｎｍ发射与Ｅｕ＾３＋的激发态能级的能量重叠，Ｅｕ＾３＋产生较强的５９８ｎｍ和６１８ｎｍ发射。另外，掺入少量Ｂｉ＾３＋     

纳米YSZ：Eu^3＋粉末的制备及光谱研究

本文用化学共沉淀法制备出掺Ｅｕ＾３＋离子的Ｙ２Ｏ３稳定的纳米立方相ＺｒＯ２ 末，并在不同温度下烧结获得不同晶粒度的粉末，分别用Ｘ射线及ＴＥＭ对粉末的晶粒度进行了分析。通过对不同晶粒度的样品进行激发谱和荧光谱的研究表明，随晶粒度减小，ＹＳＺ：Ｅｕ＾３的激发谱峰位有红移现象，其荧光谱的＾５Ｄ０→＾７Ｆ２跃迁有变化，而且各跃迁的强度比也有改变。     

La0.5Y0.5Ni4.8Mn0.1Al0.1和La0.5Y0.5Ni4.8Al0.2合金的储氢性能研究

针对两种新型稀土型储氢合金La0.5Y0.5Ni4.8Mn0.1Al0.1和La0.5Y0.5Ni4.8Al0.2的储氢特性进行研究分析。实验表明,相同温度下,La0.5Y0.5Ni4.8Mn0.1Al0.1和La0.5Y0.5Ni4.8Al0.2合金的PCT曲线基本重合,且都具有优良的吸氢动力学性能;相比之下,后者的滞后系数要小于前者,吸氢量较大,吸氢速率也较快,故其储氢性能较优。300次吸放氢循环实验结果表明,La0.5Y0.5Ni4.8Al0.2合金的吸氢动力学性能虽然略有下降,但抗粉化性能较好。     

Dy0.6Tb0.3Pr0.1(Fe0.95Mn0.05)x取向晶体的结构与磁致伸缩

采用Ｃｚｏｃｈｒａｌｓｋｉ方法生长了Ｄｙ０．６Ｔｂ０．３Ｐｒ０．１（Ｆｅ０．９５Ｍｎ０．０５）ｘ（１．８５≤ｘ≤１．９５）取向合金。所有合金主相为立方Ｌａｖｅｓ相结构,择优取向不完整择优取向的方向与Ｘ的大小有关。研究了沿着这些样品的生长方向的磁致伸缩性能以及磁致伸缩性能与压力之间的关系。     

Thermal Stability of Amorphous Hydride Mg_(50)Ni_(50)H_(54) and Mg_(30)Ni_(70)H_(45)

The thermal stability of amorphous ternary hydrides Mg_(50)Ni_(50)H_(54) and Mg_(30)Ni_(70)H_(45) and their corre-sponding amorphous binary alloys Mg_(50)Ni_(50) and Mg_(30)Ni_(70) were studied with X-ray diffraction(XRD) and differential scanning calorimetry(DSC). Samples of the amorphous alloys were preparedby mechanical alloying and the amorphous hydrides were obtained by charging the alloys with gas-eous hydrogen at 3.0 MPa and 423 K. It was found that the amorphous hydrides released most oftheir hydrogen before the crystallization of the essentially hydrogen depleted amorphous alloy. Thecrystallization temperature of amorphous Mg_(50)Ni_(50)H_(54) elevated and that of amorphousMg_(30)Ni_(70)H_(45) did not change in relation to the original binary amorphous alloy. This is very excep-tional for amorphous hydrides. The reason for the effects of hydrogen absorption/desorption on thecrystallization of amorphous alloys was discussed.     

Zr65Al7.5Ni10Cu15Co2.5合金的玻璃转变温度

根据Ｚｒ６５Ａｌ７。５Ｎｉ１０Ｃｕ１５Ｃｏ２。５合金的纳米晶，晶体，液体和玻璃比热的测量结果，研究了合金的玻璃转变温度与全金的热力学函数，动力学参数以及加热速度的关系。结果表明，非晶态合金玻璃转变所需转变激活能很小，玻璃转变温度实际上是由于加热速度引起的不同状态的玻璃与液体的热力学平衡温度。     

Acousto-optic interaction in alpha-BaB(2)O(4)and Li(2)B(4)O(7) crystals

Experimental studies and analysis of acousto-optic diffraction in alpha-BaB(2)O(4) and Li(2)B(4)O(7) crystals are given. Ultrasonic wave velocity, elastic compliance and stiffness coefficients, and piezo-optic and photoelastic coefficients of alpha-BaB(2)O(4) and Li(2)B(4)O(7) crystals are determined. The acousto-optic figure of merit has been estimated for different possible geometries of acousto-optic interaction. It is shown that the acousto-optic figures of merit for alpha-BaB(2)O(4) crystals reach the value M(2)=(270 +/- 70) x 10(-15) s(3)/kg for the case of interaction with the slowest ultrasonic wave. The directions of propagation and polarization of those acoustic waves are obtained on the basis of construction of acoustic slowness surfaces. The acousto-optic diffraction is experimentally studied for alpha-BaB(2)O(4) and Li(2)B(4)O(7) crystals.     

Natural Passivity of Amorphous Fe_(40)Ni_(40)P_(14)B_6 and Fe_(54.6)Ni_(38)Si_(4.1)B_(2.3)V_1 Alloys

The natural passive films forrned on Fe_(40)Ni_(40)P_(14)B_6 and Fe_(54.6)Ni_(38)Si_(4.1)B_(2.3)V_1 amorphous alloys long-term exposed in air have been studied by X-ray photoelectron spectroscopy (XPS) and Auger electron (including Ar+ ion depth profiling) spectroscopy (AES). The following aspects have been investigated: (1) chemical states of the elements in the films. binding energies and the chemical shifts measured by XPSf (2) structure and composition of the films fand (3) thickness of the passive films determined by AES depth profiling and XPS analysis.     

Nanomechanical characterization of one-step combustion-synthesized Al(4)B(2)O(9) and Al(18)B(4)O(33) nanowires

Two kinds of aluminum borate nanowires, Al(4)B(2)O(9) and Al(18)B(4)O(33), were successfully synthesized by a one-step combustion method through control of the Al:B atomic ratio and synthesis temperature. Both nanowires are single crystalline but have distinguishing growth habits. Nanoindentation tests were performed directly on individual nanowires to reveal their mechanical properties. A 70% reduction in elastic modulus was found in Al(18)B(4)O(33) nanowires compared with their bulk counterpart. Al(18)B(4)O(33) nanowires exhibited higher hardness and elastic modulus than Al(4)B(2)O(9) nanowires.     

Plasma surface treatments of poly(l-lactic acid) (PLLA) and poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV)

The surfaces of poly(l-lactic acid) (PLLA) and poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) were modified by oxygen and nitrogen plasma treatments. The physical and chemical surface characteristics were evaluated by contact angle tests, scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). The plasma treatments caused an increase in both contact angle and roughening, altered the surface morphology, inserted polar groups, and, consequently, enhanced the hydrophilicity for both PLLA and PHBV polymers.     

Work Functions of Pd_(83.5)Si_(16.5)and Cu_(70)Ti_(30)Glassy Alloys

The work functions before and aftercrystallization of two glassy alloys,Pd_(83.5)Si_(16.5) andCu_(70)Ti_(30) have been measured by means of the con-tact potential difference method in the secondaryelectron field at room temperature under 10~(-5) Pavacuum.The results show that the work functionsof both glassy alloys are higher than those of thecorresponding crystalline alloys.