Eu^3＋掺杂的ZnF2-ZnO纳米结构材料及其发光、光催化性能

采用水热法,结合后续的热处理,制备了Eu^3＋掺杂的ZnF2-ZnO纳米结构材料,利用X-射线衍射仪（XRD）、扫描电子显微镜（SEM）和荧光光谱仪对样品结构、形貌及发光性能进行表征．结果表明,以NaF为原料得到的样品为正方体状,长为220-400nm;以NH4F为原料得到的样品呈棒状,长约为1．2μm,直径为110nm左右．紫外光激发下,棒状样品发光性能强于立方体状的样品,表现为掺杂Eu^3＋的特征发射．光催化脱色实验表明,两种形貌样品的光催化活性差别不大,150min对甲基橙的脱色率达70％左右．     

一种新型联苯乙烯衍生物--蓝色有机电致发光材料

A new blue electroluminescent material,distyrylarylene(DSA)derivative,4,4‘-bis[2,2-(1-naphthyl,phenyl)vinyl]-1,1-biphenyl(NPVBi)is designed and synthesized.The DSA derivative shows better thermal stability because of its high glass transition temperature.A blue organic light emitting diode(OLED0with the structure ITO/TPD/NPVBi/Alq/LiF/Al is studied.The electroluminescent(EL0spectrum of the OLED exhibits that light emission originates from NPVBi with a peak at 460nm,its Commission Internationale de l‘Eclairage(CIE)color coordinates are x=0.16,y=0.15,and showing independence of CIE color coordinates on current density.The new DSA derivative is expectable as a new candidate for blue light emitter in OLEDs.     

电感耦合等离子体光源的研究及应用前景

电感耦合等离子体光源(ICP光源)是一种很好的原子化源、离子化源和激发源,常被用作原子发射光谱分析的激发光源,在环境科学、材料科学、生命科学、地质分析、冶金分析等领域有着广泛的应用。文章对ICP光源的发明历史、结构组成、各项性能、工作原理以及日常维护的注意事项进行了分别阐述,并对ICP光源在质谱技术(ICP-MS)、原子荧光光谱技术(ICP-AFS)、原子吸收光谱技术(ICP-AAS)、气相色谱技术(ICP-AES-GC)、液相色谱技术(ICP-AES-HPLC)等领域的应用前景作了简要概述。     

高校写作教材建设初探

一些写作教材的建设似乎已经步入误区 ,出现了新的流弊 ,其表现为无的放矢的空洞说教 ,食而不化的盲目引进 ,随意性大 ;写作教材应该向写作自身的深层次发展 ,总结和概括出写作最一般的规律和方法 ,真正体现写作的特点     

Ultrastructural characters of a Physarum melleum on living leaves of Dendrobium candidum in China

A known species, Physarum melleum, was found fruiting on living leaves of Dendrobium candidum, which was collected in China in 2004. Its morphological characters were revealed by light microscopy (LM), environmental scanning electron microscopy (ESEM) and scanning electron microscopy (SEM). Character variations were distinguished by its olive-yellow peridium and its always thinner capillitium containing globulose granular material between the large calcareous nodes. The calcium carbonate granules, deposited on stalks, peridium and hypothallus as well as within stalks, were globose and smooth. Project (No. 2001BA744C) supported by the 10th Five-year National Key Technologies R & D Program, China     

mpg-C3N4/BiVO4异质结光催化剂的制备及其降解复方磺胺甲恶唑的效果研究

采用水热合成法制备了典型的手里剑型钒酸铋晶体（BiVO₄）,利用硬模板法制备了介孔氮化碳材料（mpg-C₃N₄）,运用超声分散的方法将二者复合,制得mpg-C₃N₄/BiVO₄异质结光催化剂。文章考察了其在可见光条件下降解复方磺胺甲恶唑的效果,并探讨了影响降解效果的因素。     

一种新型的白光LED用红色荧光粉SrMoO4:Eu3+

采用固相法合成了红色荧光粉SrMoO4:Eu3 并对它的发光性质进行了研究。它的激发谱为双峰结构,两主峰分别位于394nm的近紫外区和464nm的蓝色可见光区。发射谱为线谱,主峰峰值为624nm,这是能与紫外和蓝色芯片符合的很好的红光。所以它是一种很好的制备白光LED用的荧光粉材料。     

Sol-Gel Synthesis and Luminescence of Green Light Emitting Phosphors Zn2SiO4/Mn^2＋

MN2 DOPED ZN2SIO4 PHOSPHORS WERE SYNTHESIZED BY SOL-GEL METHOD, AND THE INFLUENCE OF ZINC SOURCE. MN2 DOPANT CONCENTRATION AND ANNEALING TEMPERATURE WERE INVESTIGATED. RESULTS SHOW THAT ZINC NITRATE BASED PRECURSOR WITH STRONG GREEN EMISSION INTENSITIES IS BETTER THAN ZINC ACETATE BASED PRECURSOR. THE INTENSITY OF GREEN LIGHT EMISSION REACHES A PEAK AT 254 NM WHEN THE MN2 DOPANT CONCENTRATION IS ABOUT 5%( MOLAR PERCENTAGE). STRUCTURAL DETAILS OF THE PHOSPHORS WERE EXAMINED THROUGH X-RAY DIFFRACTOMETRY. THERMOGRAVIMETRIC AND DIFFERENTIAL THERMAL ANALYSIS. THE RESULT INDICATES THAT THEY ARE BOTH RHOMBOHEDRAL STRUCTURES, WHICH REMAIN AMORPHOUS BELOW 700 ℃ AND CRYSTALLIZE COMPLETELY AROUND 1 000 ℃. THE LUMINESCENT PROPERTIES OF ZN:SIO4/MN2 PHOSPHORS WERE CHARACTERIZED BY EXCITATION AND EMISSION SPECTRA.     

“激光原理”研究性学习的实践探索

研究性学习可以加深对专业知识中基本概念和原理的理解和掌握,培养学生综合应用所学专业知识分析问题和解决问题的能力。以“激光原理”中光纤激光器为主题的实验研究性学习专题设计为例,通过对专题的研究性学习,学生能深刻理解激光器的基本组成、激光产生和形成的基本原理、光和物质相互作用的基本物理过程中自发辐射和受激辐射的本质区别和关系。此研究性学习方法很容易推广到其他专题,对光电信息专业课中开展研究性学习具有指导价值。     

Er^3＋：Y0.5Gd0．5，VO4晶体光谱性质研究

测量了1．62at％-Er^3＋ Y0.5Gd0．5，VO4晶体的吸收光谱和荧光发射谱，光谱显示该晶体在382、525、1536nm有很强的偏振光吸收峰，且偏振光（E∥C）吸收远强于σ偏振光（E⊥C）吸收；通过计算可得，吸收截面分别为2．95013×10^-20cm^2、2．57757×10^20cm^2和1．15504×10^-20cm^2；其荧光发射（^4I15／2→^4I11／2跃迁）峰值波长在1524nm，半高宽度为72nm；415/2^I→^4I11/2跃迁的荧光寿命为3．1ms,光谱特性表明Er3^＋：Y0．5，Gd0．5，VO4晶体是潜在的高效率激光晶体材料．     

单泡声致发光研究

综述了单气泡声致发光(SBSL)这种新奇的现象.由于SBSL现象在时间和空间的高度重复性,为实验研究气泡的运动特性和影响发光参数(含气量,水温,声压等)提供了可能.介绍了解释声致发光发原因的四种发光机理,并对各自的优缺点进行了分析.展望了单气泡声致发光现象在化学分析,医学检测等多个领域的应用前景.     

Molecule matters Metal organic frameworks (MOFs)

Storage space is a perennial problem not only in macroscopic world but at the molecular level as well. Efficient storage of certain gases such as hydrogen, methane etc has futuristic technological applications. Therefore, race is on for the discovery of new materials with largest storage capacity per gram of the material. Metal organic framework (MOF) materials are a class of light weight hybrid materials with surface areas per gram that could cover an entire foot ball field. This article gives a glimpse of the recent advances in MOFs.     

土工布在水利工程中的应用

土工布是土工合成材料的一种,被广泛运用于水利,公路,铁路等土木工程中,起到加固,排水,隔离和过滤等作用,本根据土工布的品种和性能特点,阐述了土工布在水利工程中的应用及与工程的合理匹配。     

An easily constructed monochromator

A functional monochromator model in a cardboard box, made from rotatable grating using a digital versatile disk is described to highlight the working principles of a UV-Vis monochromator. The light source is a bright white LED and the colored bands from the exit are displayed on the screen. The concept of absorption, complementary color, excitation and fluorescence, flame emission spectrum, and wavelength dependence of light scattering can be visually shown in this model. With a minor modification, one can use the same box to monitor flame emission spectrum of sodium and different light sources. As an optional activity, the same properties are observed on a scanning spectrophotometer.     

独山玉致色矿物及颜色成因研究

独山玉因产于河南南阳北郊的“独山”而得名,具有“色俏质润”的特点,是与和田玉、岫岩玉、绿松石齐名的“中国四大名玉”之一。独山玉是迄今为止世界上发现的唯一达到玉石工艺要求的“斜长石质”玉石。相较于翡翠、和田玉等名玉,独山玉的研究程度较低。不同颜色独山玉的矿物组合、形成原因也更为复杂。本文利用偏光显微镜、电感耦合等离子体发射光谱仪（IC P－A ES ）对各色独山玉进行了测试分析,并进行了系统的讨论,认为“致色矿物”的不同导致独山玉绚丽多彩,各色独山玉的致色元素赋存在相应的致色矿物内。     

用于白光LED的CaBa_2(BO_3)_2∶Eu~(2+)绿色荧光粉发光性质的研究

采用高温固相法制备了CaBa2(BO3)2∶Eu2+绿色荧光粉,并对其发光性质进行了研究。该荧光粉在近紫外线激发下的发射光谱为峰值位于537 nm的带状谱,对应了Eu2+的4f65d1→4f7的特征跃迁发射;监测537 nm的发射峰,得到CaBa2(BO3)2∶Eu2+激发光谱为250~500 nm的宽带谱,能与产生350~410 nm辐射的UVLED管芯很好地匹配。Eu2+掺入量和H3BO3的用量对样品发光强度都有影响,当Eu2+的掺入量达到2%,H3BO3用量为理论用量的1.03倍时,样品可达到最佳发光亮度。     

稀土掺杂NaGd(WO4)2反蛋白石光子晶体的制备及其发光性能

使用水热法合成了NaGd(WO4)2:Yb3+,Er3+,Tm3+荧光粉,借助PMMA胶体模板自组装法制备了三维反蛋白石光子晶体,并表征了样品的表面形貌和结构特征。样品具有四方晶系NaGd(WO4)2的晶格结构,电子显微镜观察到规则排布的微球蛋白石模板和退火之后形成的正六边形空腔结构。光谱测试发现,在反蛋白石光子晶体微孔直径185 nm左右时,得到了相对最强的发光增强效果;实验样品中光子带隙的存在显著增强了蓝光发光而抑制了红光发光,导致光子晶体样品整体发光从荧光粉的暖白光转变为偏绿色。对比荧光粉样品,反蛋白石光子晶体样品中Er3+离子4S3/2→4 I15/2的发光寿命显著增加,但光子带隙的变化对寿命影响不大。与参考样品相比,反蛋白石光子晶体样品对温度淬灭现象具有显著的抑制作用。     

LD泵浦Nd:GdVO4三能级激光跃迁研究

目的研究实现LD泵浦Nd：GdVO4三能级激光跃迁的相关条件.方法实验探测分析.结果得到在不同腔损耗情况下的能级跃迁光谱.结论由于发射截面大的四能级跃迁对激光上能级粒子数损耗严重,很难形成高效的三能级激光振荡,抑制四能级跃迁是获得这些三能级激光振荡的前提条件.随着腔镜对这些三能级跃迁损耗的增加,激光发射和泵浦吸收的平衡过程将导致激光发射波长蓝移.     

林农复合生态系统中的生态效应分析

本文对林农复合生态系统中的生态效应,如净生产力与经济产量,物质、能量转化,光能利用率,温、湿效应,时、空效应,土壤水分、理化性状的改变,刘病虫害的抑制效应以及刘间种作物产品的有效成分和质量的影响等等,进行了分析。结果表明,林农复合生态系统的生态效应是十分显著的,是一类行之有效的、值得推广的经营方式。     

British Colonial Higher Education Policy-making in the 1930s: The case of a plan to establish a university in Cyprus

This article examines Britain's colonial education policy in Cyprus in the late 1930s, and more specifically, its efforts to establish a university on the island. The British unpublished plan for a university in Cyprus is considered in the light of the particular social and political context of Cyprus and also in relation to Britain's broader colonial education policy. Primary source material is used as the basis for investigation and analysis.