Sol-gel fabrication and photoluminescence properties of SiO2@Gd2O3 : Eu3+ core-shell particles

A uniform nanolayer of europium-doped Gd2O3 was coated on the surface of preformed submicron silica spheres by a Pechini sol-gel process. The resulted SiO2@Gd2O3:Eu3+ core-shell structured phosphors were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), photoluminescence (PL) spectra as well as kinetic decays. The XRD results show that the Gd2O3:Eu3+ layers start to crystallize on the SiO2 spheres after annealing at 400 degrees C and the crystallinity increases with raising the annealing temperature. The core-shell phosphors possess perfect spherical shape with narrow size distribution (average size: 640 nm) and non-agglomeration. The thickness of the Gd2O3:Eu3+ shells on the SiO2 cores can be adjusted by changing the deposition cycles (70 nm for three deposition cycles). Under short UV excitation, the obtained SiO2@Gd2O3:Eu3+ particles show a strong red emission with D-5(0)-F-7(2) (610 nm) of Eu3+ as the most prominent group.The PL intensity of Eu3+ increases with increasing the annealing temperature and the number of coating cycles.

High efficiency red organic light-emitting diodes based on microcavity structure

We demonstrate high efficiency red organic light-emitting diodes (OLEDs) based on a planar microcavity comprised of a dielectric mirror and a metal Mirror. The microcavity devices emitted red light at a peak wavelength of 610 nm with a full width at half maximum (FWHM) of 25 nm in the forward direction, and an enhancement of about 1.3 factor in electroluminescent (EL) efficiency has been experimentally achieved with respect to the conventional noncavity devices. For microcavity devices with the structure of distributed Bragg reflectors (DBR)/indium-tin-oxide(ITO)/V2O5/N,N'-di(naphthalene-1-yl)-N,N'-diphenyl-benzidine(NPB)/4-(dicy-anome-thylene)-2-t-butyl-6(1,1,7,7-tetrame-thyljulolidyl-9-enyl)-4H-pyran(DCJTB):tris(8-hydroxyquinoline) aluminium (Alq(3))/Alq(3)/LiF/Al, the maximum brightness arrived at 37000 cd/m(2) at a current density of 460.0 mA/cm(2), and the current efficiency and power efficiency reach 13.7 cd/A at a current density of 0.23 mA/cm(2) and 13.3 lm/W respectively.

Rapid molecular weight determination of recombinant hirudin by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

The molecular weight of recombinant hirudin ( rHV-2) was determined rapidly by matrix-assisted laser desorption/ionization time of fight mass spectrometry (MALDI-TOF-MS). The effects of the three types of matrixes were compared and discussed, alpha-cynao-4-hydroxycinnamic acid was proved to be the best matrix. It showed that MALDI-TOF-MS was superior to the traditional method of molecular weight determination of the biological macromolecules. The mass spectrum data proved that the primary structure of rHV-2 was correct and there was no amino acid deletion, mutation and modification in its expression, refolding and purification.

应用基质辅助激光解吸质谱快速分析重组水蛭素产物的纯度与分子量

利用MALDI TOF MS测定了具有抗凝血活性的水蛭素基因重组产物 (rHV 2 )的纯度和分子量 ,实验测定结果与理论计算值一致。证明此基因重组产物的一级结构是正确的 ,在表达、复性和纯化的过程中没有氨基酸的丢失、变异和修饰。

用Z-扫描技术研究手性介质非线性圆双折射

用Z 扫描技术研究了各向同性手性介质 (聚酯酰亚胺吡啶溶液 )对于左、右圆偏振光的非线性圆双折射 ,得到在低光强下非线性旋光角的变化规律 ,验证了非线性圆双折射与非线性旋光的关系。

BaLaB_9O_(16)∶Eu,Tb的真空紫外光谱特性

采用高温固相反应法合成了 BaLaB9O1 6 ∶RE (RE =Eu ,Tb)等离子荧光体 ,测量了它们的真空紫外激发光谱和 14 7nm激发下的发射光谱。结果表明 ,硼氧阴离子基团基质吸收带位于 15 0nm附近 ,Eu3+ 电荷迁移带位移 2 5 0nm附近 ,Tb3+ 的 4f 5d吸收位于 15 0～ 2 60nm的区域内 ,相关数据表明 ,基质与稀土离子之间存在能量传递。

增强辣根过氧化物酶催化鲁米诺化学发光反应的新型增强剂四苯硼钠

报道了新型增强剂四苯硼钠对过氧化物酶催化鲁米诺－过氧化氢发光反应的增强作用，建立了流动注射化学发光测定或辣过氧化物酶(HRP)的新体系。用该体系测定HRP线性范围为1.0×10－12×1.2×10－13mol/L；检测限为0.6×10－13mol/L。对0.6×10－13mmol/L的HRP进行11次平行测定，相对标准偏差为1.5%。

宽时域宽频域分子荧光寿命测试系统

设计组装了宽时域（１０－３ｓ～１０－９ｓ）和宽频域（激发波长几乎可以复盖３３７～８００ｎｍ波长）的激光光源分子荧光寿命测试系统。系统中配置了Ｎ２分子激光，Ｎｄ：ＹＡＧ激光及其泵浦的染料激光和美国ＥＧ＆Ｇ公司的４４００型信号检测和分析系统。通过对硫酸奎宁，荧蒽和稀土络合物典型样品的检测表明该仪器系统性能稳定，结果可靠。

粉状巯基棉富集——水中痕量CH_3Hg~+及Hg~(2+)的冷原子荧光测定

本文提出了一种新的高巯基粉状巯基棉的合成方法,按此法合成的流基棉含量在2.2%～2.5%之间.在盐酸介质中,用溴水在室温下快速分解甲基汞,冷原子荧光测定的新方法.将粉状巯基棉与稀释剂按一定比例混合装柱,用于富集水体中溶解态痕量Hg~(2+)和CH_3Hg~+,富集流速100ml/min.检出限CH_3Hg~+为4.2×10~(-5)μg/l,Hg~(2+)为6.6×10~(-5)μg/l.

(C_8H_8)Sm(C_8H_8)Na(THF)_3的晶体结构

(C_8H_8)Sm(C_8H_8)Na(THF)_3的晶体属单斜晶系,P2_1空间群.晶胞参数为α=12.140(3),b=13.794(3),c=8.944(3)(?),β=111.68(3)°,V=1391.8(7)(?)~3,Z=2,μ=21.93cm~(-1),D_c=1.43g/cm~3,F(000)=610,Mr=598.0。结构经Patterson函数和Fourier技术解出并经最小二乘修正,最终的偏离因子R为0.046.配合物具有双层夹心结构.其中Sm~(3+)和Na~+通过η~8-环辛四烯基连接。

激光光热干涉光谱分析方法研究

本工作设计了一种新的激光光热干涉光谱装置,类似于Mach-Zehnder干涉仪的光路构型,采用探测束聚焦和泵浦束与探测束相交的光学结构,光路容易调整稳定性较好.文章讨论了方法的原理,详细研究了影响光热干涉信号的实验参数,获得结晶紫的检测下限为8.0×10~(-8)mol/L,相应的最小吸光度为3.6×10~(-6)。

γ辐照新型聚芳醚酮的介电行为

对γ辐照新型聚芳醚酮(PEK-C)的介电行为进行研究。20—200℃范围内的介电温度谱和30Hz—1MHz的频率谱表明。经过2.02 MGy剂量辐照后,PEK-C的介电行为发生了明显变化,不仅谱图形状有了改变,而且因辐照的PEK-C结构中产生了稳定的三苯自由基,介电系数ε′和介电损耗因子ε″大幅度增加,在20℃,1kHz时前者由3上升到5,后者由5.4×10~(-3)上升到4.6×10~(-1)。

MISCIBILITY OF POLY(N-VINYL-2-PYRROLIDONE) WITH A COPOLYAMIDE

Blends of poly(N-vinyl-2-pyrrolidone) (PVP) with a copolyamide (CoPA) randomly composed of 1:1:1 (wt) nylon 6, nylon 66 and nylon 610 structural units were prepared by casting from a common solvent. They were found to be miscible and show a single, composition-dependent glass transition temperature (T(g)). The addition of PVP to CoPA significantly lowers the crystallinity owing to an increasing T(g) of the system. The observed miscibility is proposed to be the result of specific interactions between the proton acceptor groups of PVP and the amide groups of CoPA.

含酚酞侧基聚芳醚砜的辐射交联

研究了含酚酞侧基聚芳醚砜(PES-C)的辐射效应,发现在真空下通过γ射线辐照,PES-C发生交联。而且在高温下PES—C的辐射交联程度比在常温下的高。在25℃下,PES-C的凝胶化剂量为6.6×10~5Gy。而在300℃下,PES-C的凝胶化剂量为6.0×10~4Gy。

改性硅橡胶富氧膜的制备

富氧膜是近年来发展起来的一种能制备富氧空气的新技术。目前国内外使用最广的富氧膜材料是甲基硅氧烷(通常称为硅橡胶)它的透氧系数Po_2=6×10~(-8)cm~3(STP)·cm/cm~2·S·cmHg,C_(O_2/N_2)=2.0,透气速度快,但机械性能较差,须予以改性,改