Luminescence Property of Phosphor Gd 3Ga 5O 12 :Ag

采取在不同的温度下烧结不同的时间方法制备了一种新型的兰色发学材料,用Ｘ光衍射对材料的结构进行了分析．并利用电子束蒸发的方法制备该材料的薄膜电臻发光器件．对该器件进行了光致发光,电致发光,亮度电压等发光性质进行了测试．得出器件亮度大约为２尼特     

血管内皮生长因子反义核酸增强HL60和K562细胞对As_2O_3的敏感性

目的:探讨血管内皮生长因子(VEGF)反义核酸能否提高HL60和K562细胞对三氧化二砷(As2O3)的敏感性。方法:采用经筛选所得的最优反义核酸(A7),20个碱基经过全硫代修饰;以脂质体介导转染细胞,反义核酸和As2O3联合作用72h以后,用MTT法检测细胞生长情况,求IC50值;用ELISA法检测培养液中VEGF蛋白的浓度,用流式细胞仪检测细胞凋亡百分数。结果:VEGF反义核酸可显著降低HL60、K562细胞对As2O3的IC50值,下调VEGF蛋白的表达,增加As2O3诱导的HL60、K562细胞凋亡作用。结论:VEGF反义核酸具有增强HL60和K562细胞对As2O3的敏感性,增强As2O3诱导的HL60和K562细胞凋亡作用;提示内源性VEGF蛋白具有使细胞产生耐药性的作用。     

一种新型有机发光材料的光致发光和电致发光

一种新型有机发光材料的光致发光和电致发光刘星元１）印寿根２）李文连１）黄文强２）虞家琪３）（１）中国科学院长春物理研究所，长春１３００２１；２）南开大学吸附分离功能高分子材料国家重点实验室；３）中国科学院激发态物理开放研究实验室）关键词有机材料，光...     

B离子注入n(Si)-GaAs层的特性研究

B~+注入n(Si)-GaAs层,可以在带间引入与损伤相关的深能级,补偿自由电子,使n型导电层变为高阻层。若注B后退火,在一定的退火条件下,在GRAs晶格的恢复过程中,B占据Ga的位置,形成B_(Ga),并与As空位V_(As)络合形成络合物B_(Ga)V_(As)。由于B_(Ga)V_(As)和Si的相互作用,促使Si占据As的位置,形成受主,从而降低了n(Si)-GaAs层中的载流子浓度。我们认为B注入n(Si)-GaAs层光发光测量中观察到的1.33 eV峰与B,Si相关。     

As2S3纳米粒的制备及其对肝癌SMMC-7721细胞的治疗作用

研究了雌黄纳米粒的制备方法及其抗肿瘤作用.采用化学方法制备A s2S3纳米粒,通过透射电镜、X射线能谱(EDS)对A s2S3纳米粒进行分析表征,以形态学、MTT法和流式细胞术体外研究不同浓度的A s2S3纳米粒对肝癌SMMC-7721细胞生长的影响,并同时与传统剂型的A s2S3进行比较.分析结果显示:实验制备的A s2S3纳米粒平均直径约为80nm,电镜下呈圆形,大小较一致,分散性较好,EDS证实其为A s2S3,无其他成分;A s2S3纳米粒对SMMC-7721细胞有明显的生长抑制和凋亡诱导作用,且呈浓度和时间依耐性,其细胞生长抑制率和凋亡诱导率明显高于相同浓度传统剂型的A s2S3处理组(p<0.001).表明化学法可以制备A s2S3纳米粒;与传统剂型的A s2S3相比,A s2S3纳米粒有更强的抗肿瘤作用.     

InGaN太阳能电池材料的辐射性质

对采用分子束外延生长的In1-xGaxN薄膜与金属有机化学气相沉积生长的GaAs和Ga0.51In0.49P薄膜太阳能电池材料进行了对比研究,探讨了全太阳光谱材料系In1-xGaxN合金薄膜受到高能粒子辐射后的电学特性变化规律。实验结果显示:GaAs和Ga0.51In0.49P的光致发光信号强度受到照射的强烈压制,而受到类似剂量照射后InN的光致发光信号强度没有下降;In1-xGaxN合金薄膜材料的电学特性表现出用高能质子(2MeV)照射比当前常用的GaAs和GaInP光伏材料有更高的电阻。这表明,In1-xGaxN对高能粒子损伤没有GaAs和GaInP那么敏感,从而给空间受到强辐射的高效太阳能电池提供了巨大的应用潜力。     

Investigation of microenvironment-depended photoluminescence in Eu3+-implantation of GaN

GaN thin films grown on sapphire were implanted by Eu~3+ with three different fluences (5.0×10~14 , 2.5×10~15 and 5.0×10~15cm~-2 ). The photoluminescence (PL) spectra show that, after annealing, the samples exhibit strong emission at around 622.0 nm under 325 nm laser excitation. The intensity of this emission increases by one order of magnitude after annealing at from 600 ℃ to 900 ℃. Moreover, it increases less than 2 times when the fluence increases from 5×10~14 cm~-2 to 5×10~15 cm~-2 for the sample annealing at 900 ℃. The PL emission peaks around 622 nm of samples annealing at 900 ℃ can be well clarified by Gaussian fitting into 620.2, 622.0 and 625.0 nm, which are due to the Eu~3+ related with defects, Eu~3+ occupied at substitutional positions of Ga, and that located at interstitial sites, respectively. It shows that the different microenvironments and positions of Eu~3+ are responsible for these peaks, and especially the defects introduced by implantation play an important role in the behavior of the PL because they set up an energy transmission bridge from exotic photons to Eu~3+ .     

Photoluminescence and Electroluminescence on Nanosilicon Deposited by Yb

Dynamics of photoluminescence（ PL） and electroluminescence（ EL） on nanosilicon deposited by Yb is investigated. The sharper PL peaks near 700 nm are observed on silicon quantum dots（ Si QDs） coated by Yb. The enhanced EL peaks in the wavelength region from 1 200 nm to 1 600 nm are measured on silicon film deposited by Yb. It is discovered that the EL intensity enhances and the peaks number increases with increasing number of Si-Yb layers. The emission wavelength could be manipulated into the window of optical communication by SiYb bonding on nanosilicon. Si-Yb quantum cascade and PIN hybrid light-emitting diode is designed to apply in optical communicating,which is suitable to be integrated on silicon chip.     

NiAl晶体中点缺陷的模拟

利用嵌入原子法（ＥＡＭ）势函数,通过分子静态弛豫方法ＮｉＡｌ合金中各种点缺陷的形成能进行了模拟计算。结果表明,从点缺陷的形成能来看,在ＮｉＡｌ晶格中很难形成Ｎｉ反位置缺陷,而Ａｌ原子亚点阵位置总是被占据。当合金富Ｎｉ时,Ｎｉ占据Ａｌ位置形成Ａｌ的反位置缺陷;当合金富Ａｌ时,形成Ｎｉ空位。点缺陷周围原子的位移情况及双空位形成能与空位之间间距的关系的研究表明,随着两个空位之间距离的增大,其交互作用逐渐     

High-efficiency conjugated-polymer-hosted blue phosphorescent light-emitting diodes

Highly-efficient blue phosphorescent light-emitting diodes were fabricated based on a conjugated-polymer host by doping bis(2-(4,6-difluorophenyl)-pyridinato-N,C2’) picolinate(FIrpic) into poly(9,9-dioctylfluorene)(PFO).Previously,conjugated polymers were not considered as potential hosts for blue phosphorescent dyes because of their low-lying triplet energy levels.Energy back transfer would occur and lead to poor luminescent efficiency in both photoluminescence(PL) and electroluminescence(EL) processes.However,by inserting a hole-transporting layer of poly(N-vinylcarbazole)(PVK),the energy back transfer was suppressed.At low FIrpic-doping concentrations,PFO emissions were completely quenched;with 8 wt% FIrpic,a maximum luminous efficiency of 11.5 cd/A was achieved.