Sr3Gd(PO4)3:Tm3+的真空紫外光谱特性

研究了Sr3Gd(PO4)3 : Tm3 和GdPO4 : Tm3 样品的结构特性、光谱特性.GdPO4 : Tm3 为单斜晶系,基质掺入铥离子后结构没有明显变化.GdPO4:Tm3 在164和210 nm附近有强烈的吸收峰.位于164 nm附近的强烈的吸收峰是归因于基质的吸收引起,210 nm附近的吸收峰则归因于Gd 的8S7/2-6GJ的能级跃迁.在164 nm真空紫外光激发下,样品于453及363 nm处有较强的发射峰,发射主峰位于453nm,属于Tm3 的1D2→3H4(22,123 cm-1)跃迁的典型发射.由于阳离子质量的不同,Sr3Gd(PO4)3:Tm3 在166 nm附近的激发峰高于GdPO4: Tm3 的同位置的激发峰,其在363 nm处的发射有明显减弱,而在453 nm处的蓝色发射有显著的增强.     

稀土氧化钕对铝酸盐长余辉发光材料性能的影响

制备了SrAl2O4:Eu2 ,Nd^3 和SrAl2O4:Eu^2 ,Dy^3 ,Nd^3 长余辉材料,研究了所合成的材料在不同波段紫外光激发条件下的发光光谱和激发光谱的差异和Eu^2 ,Dy^3 ,Nd^3 的摩尔掺杂浓度对材料的余辉性能的影响等。     

一种新结构ZnS∶Tm~(3 )薄膜电致发光器件的研究

采用电子束蒸发法制备了一种新结构 (ITO/SiO2 /ZnS∶TmF3/SiO2 /ZnS∶TmF3/SiO2 /Al)的薄膜电致发光器件 ,并与传统双绝缘层结构的器件相比较。结果表明 ,新结构器件的发光蓝红外比和发光亮度要明显高于双绝缘层结构的器件。分析认为这是由于SiO2 夹层起到了加速电子和提供界面的作用     

Facile and controllable synthesis of molybdenum disulfide quantum dots for highly sensitive and selective sensing of copper ions

Molybdenum disulfide quantum dots(MoS_2QDs) were synthesized via a hydrothermal method using sodium molybdate and cysteine as molybdenum and sulfur sources, respectively. The optimal hydrothermal time was studied. Furthermore, the as synthesized water-soluble MoS_2QDs were used as a fluorescence probe for the sensitive and selective detection of copper ions. The fluorescence of the MoS_2QDs was quenched after the addition of copper ions; the reason may be that the transfer of the excited electron from QDs to copper ions leads to the reduction of the radiative recombination.The fluorescence quenching of MoS_2QDs is linearly dependent on the copper ions concentration ranging from 0.1 μM to600 μM, the limit of detection is 0.098 μM, which is much lower than that of existing methods. Moreover, the MoS_2QDs show highly selectivity towards the detection of copper ions.     

还原石墨烯与片状氧化镍复合材料的隐身性能

采用一锅法制备还原石墨烯与片状氧化镍复合材料。复合材料的结构形貌、晶型和电磁参数分别通过扫描电镜、透射电镜、X射线衍射仪以及HP8722ES型矢量网络分析仪进行表征、测试与分析。结果表明,还原石墨烯与片状氧化镍复合材料同纯还原石墨烯相比在低频段(2.0~6.6 GHz)有更佳的吸收宽度和微波吸收能力,还原石墨烯与氧化镍片复合材料的介电损耗显著增加。大尺寸氧化镍片与还原石墨烯紧密复合提高了材料的载流子迁移率,从而提高了材料的吸波特性。     

In situ growth of different numbers of gold nanoparticles on MoS_2 with enhanced electrocatalytic activity for hydrogen evolution reaction

Producing hydrogen through a hydrogen evolution reaction(HER) by splitting water at the suitable overpotential is a great alternative to solving the problems of environmental pollution and the energy crisis. Molybdenum sulfide(MoS_2)has attracted extensive attention as one of the most promising catalytic materials for HER. In this work, we design a facile method to in situ grow gold nanoparticles(Au NPs) on MoS_2. Different numbers of Au NPs with MoS_2 are used to find the best catalytic activity. Due to the larger active surface area and higher conductivity of the Au–MoS_2 composites, all the Au–MoS_2 composites exhibit more enhanced HER electroactivity than pure MoS_2. In brief, the new material architecture exhibits optimized HER activity with a low onset overpotential of 0.12 V, low Tafel slope of 0.163 V·dec~(-1), and an excellent stability in acidic solution.     

Ba_2MgSi_2O_7∶RE荧光粉发光性能的研究

采用高温固相法合成了Ba2MgSi2O7∶RE(RE=Eu2 ,Ce3 ,Tb3 )系列荧光粉,研究了其结构和光谱特性。样品的XRD衍射图表明稀土离子的掺入没有引起基质晶格结构的变化。样品Ba2MgSi2O7∶Ce3 在紫外光激发下呈蓝紫色发射,而样品Ba2MgSi2O7∶Eu2 在紫外光激发下呈绿色发射。对样品Ba2MgSi2O7∶Eu2 的光谱分析表明Eu2 在焦硅酸钡体系中可能占据两个不同格位。此外还分析了Ce3 ,Eu2 和Ce3 ,Tb3 共激活焦硅酸钡盐在紫外光激发下的光谱特性,并对其中存在的能量传递机理进行了讨论。     

激光电视动态校靶靶标研制

１　引　　言目前，国外在航空火控系统中，以英、美两国最为先进，美国研制了各种红外吊舱，尤以蓝天吊舱为代表，它集合雷达，前视红外，激光测距与指示，编码制导跟踪为一体．美国蓝天吊舱中，只设计激光和前视红外的组合系统和动态校靶系统，没有牵涉到激光与电视的组合问题，吊舱系统中靶标采用紫外激发磷光体，当激光照射磷光体时，使得靶标照射处亮度骤然下降，再被电视接收后进行校靶．首次研制并采用上转换材料为动态校靶系统提出一种新的校靶方案．２　原　　理校靶系统的基本原理是制作一块靶标、靶标被激光照射处瞬间发生出绿光…     

2(Ba_(1-x)Sr_xO)(1-y)P_2O_5·yB_2O_3∶Eu~(2+)的发光性能(英文)

合成了系列2(Ba1 -xSrxO) (1 -y)P2O5·yB2O3∶Eu2 样品,研究了样品在长波紫外区域的激发光谱和发射光谱。从激发谱可以看出:2(BaO)(1 -y)P2O5·yB2O3∶Eu2 在300 ~380 nm附近区域有很强的吸收带,在380 nm紫外光激发下,2(BaO)·(1 -y)P2O5·yB2O3∶Eu2 的发射带位于400 ~430 nm;在2(Ba1 -xSrxO)-(1 -y)P2O5·yB2O3∶Eu2 的系列样品中,当x>0.2时,随着x的增大,基质晶格在330 ~380 nm吸收带整体向低能方向移动了40 nm;在147 nm激发下的发射谱是主峰值位于478 nm的蓝绿光发射。     

An optimized,sensitive and stable reduced graphene oxide–gold nanoparticle-luminol-H2O2 chemiluminescence system and its potential analytical application

The chemiluminescence （CL） performance of luminol is improved using reduced graphene oxide/gold nanoparticle （rGO-AuNP） nano-composites as catalyst. To prepare this catalyst, we propose a linker free, one-step method to in- situ synthesize rGO-AuNP nano-composites. Various measurements are utilized to characterize the resulting rGO-AuNP samples, and it is revealed that rGO could improve the stability and conductivity. Furthermore, we investigate the CL signals of luminal catalyzed by rGO-AuNP. Afterwards, the size effect of particle and the assisted enhancement effect of rGO are studied and discussed in detail. Based on the discussion, an optimal, sensitive and stable rGO-AuNP-luminon- H202 CL system is proposed. Finally, we utilize the system as a sensor to detect hydrogen peroxide and organic compounds containing amino, hydroxyl, or thiol groups. The CL system might provide a more attractive platform for various analytical devices with CL detection in the field of biosensors, bioassays, and immunosensors.