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71.
胶束增溶分光光度法测定矿石中微量铌和钽   总被引:2,自引:0,他引:2  
郭光熙 《分析化学》1990,18(6):541-544
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72.
共振散射光谱技术是利用荧光分光光度计的同步扫描技术建立起来的一项光谱分析新技术,具有简便、快速、灵敏度高等优点,在蛋白质、核酸、无机离子等痕量分析中得到应用.结合本课题组近年来的研究工作,本文综述了共振散射光谱技术在免疫纳米催化、核酸适配体纳米催化分析中的应用.  相似文献   
73.
<正>A new homoflavonoid was isolated from the seed of Caesalpinia minax Hance.On the basis of spectral evidences,its structure was established and named as minaxin.  相似文献   
74.
李变霞  曾光晰 《光子学报》1992,21(2):152-155
本文介绍了一种新型光纤高温传感器。它具有响应速度快、精度高、稳定性好等特点。  相似文献   
75.
In this progress report, seven kinds of novel carefully designed and fabricated up-conversion luminescence agents, Er3+:Y3Al5O12, Er3+:YbnY3?nAl5O12, Er3+:Y3BaAl5?aO12, Er3+:Y3GabAl5?bO12, Er3+:Y3Al5NxO12?x, Er3+:Y3Al5FyO12?y and Er3+:YbnY3?nBaGabAl5?a?bNxFyO12?x?y, are successfully synthesized using sol–gel methods. After that, their corresponding photocatalysts, Er3+:Y3Al5O12/TiO2, Er3+:YbnY3?nAl5O12/TiO2, Er3+:Y3BaAl5?aO12/TiO2, Er3+:Y3GabAl5?bO12/TiO2, Er3+:Y3Al5NxO12?x/TiO2, Er3+:Y3Al5FyO12?y/TiO2 and Er3+:YbnY3?nBaGabAl5?a?bNxFyO12?x?y/TiO2, are also prepared by sol–gel coating process. The obtained up-conversion luminescence agents and photocatalysts were characterized by using XRD, XPS, SEM, UV–vis and fluorescence spectrophotometer. Synchronously, several kinds of organic dyes are used to test their photocatalytic degradation using prepared photocatalysts. It indicates that the up-conversion luminescence ability of Er3+:Y3Al5O12 can be improved obviously through doping of some elements. And then, the photocatalytic activity of TiO2 is markedly enhanced by modified up-conversion luminescence agents which can transform much visible light into ultraviolet light.  相似文献   
76.
Recently,research of crystalline-state transformation involving the removal/inclusion of guest molecules in porous coordination polymers(PCPs) was underway.Crystalline-state transformation,especially,single-crystal to single-crystal(SC-SC) transformation as new method for the direct observation of host-guest chemistry,can reveal the intrinsic relevance and interaction between the framework and guest molecules.This review describes our work concerning PCPs and recent investigations of others,within the last ...  相似文献   
77.
Curcumin, a widely used coloring agent and spice in food, has a potential in blocking brain tumor formation and curing Alzheimer’s disease. Due to the specific properties of blood–brain barrier (BBB), only traces of curcumin were transported across BBB. The aim of the present study was to design and characterize curcumin loaded polybutylcyanoacrylate nanoparticles (PBCN) coated with polysorbate 80, and to evaluate the effect of PBCN as a delivery system on carrying curcumin across BBB. Curcumin loaded nanoparticles were prepared by an anionic polymerization method, and they presented in a core–shell spherical shape under transmission electron microscopy, with an average diameter of 152.0 nm. The average drug loading was 21.1%. Physicochemical status of curcumin in the nanoparticles was confirmed with differential scanning colorimetry and Fourier transform infrared spectroscopy. The in vitro release behavior of drug from the nanoparticles was fitted to a double phase kinetics model. The studies of pharmacokinetic and bio-distribution to brain were conducted in mice after intravenous administration of the nanoparticle formulation at the dose of 5 mg/kg and curcumin solution at the dose of 10 mg/kg via the tail vein. The results showed that in plasma, the area under concentration–time curve (AUC0–∞) for curcumin loaded nanoparticles was greater than that for the control solution, moreover, the mean residence time of curcumin loaded nanoparticles was 14-fold that of the control solution. In brain, AUC0–∞ for curcumin loaded nanoparticles was 2.53-fold that for the control solution. In conclusion, the present study demonstrated that PBCN could enhance the transport of curcumin to brain and have a potential as a delivery system to cross the BBB.  相似文献   
78.
The CeO2/TiO2, SnO2/TiO2 and ZrO2/TiO2 composites were prepared by dispersing various nano-sized oxides (CeO2, SnO2, ZrO2 and TiO2) with ultrasound and mixing TiO2 with CeO2, SnO2 and ZrO2, respectively, in boiling water in a molar ratio of 4:1, followed by calcining temperature 500 °C for 60 min. Then a series of sonocatalytic degradation experiments were carried out under ultrasonic irradiation in the presence of CeO2/TiO2, SnO2/TiO2 and ZrO2/TiO2 composites and nano-sized TiO2 powder. Also, the influences of heat-treatment temperature and heat-treatment time on the sonocatalytic activities of CeO2/TiO2, SnO2/TiO2 and ZrO2/TiO2 composites, and of irradiation time and solution acidity on the sonocatalytic degradation of Acid Red B were investigated by UV–vis spectra. It was found that the sonocatalytic degradation of Acid Red B shows significant variation in rate and ratio that decreases in order: CeO2/TiO2 > SnO2/TiO2 > TiO2 > ZrO2/TiO2 > SnO2 > CeO2 > ZrO2, and the corresponding ratios of Acid Red B in aqueous solution are 91.32%, 67.41%, 65.26%, 41.67%, 28.34%, 26.75% and 23.33%, respectively. And that the degradation ratio is only 16.67% under onefold ultrasonic irradiation. Because of the good degradation efficiency, this method may be an advisable choice for the treatment of non- or low-transparent wastewaters in the future.  相似文献   
79.
25MeV/u 40Ar+197Au反应中相对态布居与发射温度的提取   总被引:1,自引:0,他引:1  
在25MeV/u 40Ar+197Au反应中,对两粒子小相对动量的关联进行了测量,由P-t、α-α关联函数提取出4He、8Be的相对态布居.在对影响8Be态布居的跟随衰变作了仔细修正后得到的温度为3.5±0.81.3MeV;对4Heg.s.引入30%跟随衰变产额修正后温度为3.6±0.4MeV.  相似文献   
80.
30MeV/u 40Ar+159Tb反应中前角区复杂碎片的来源   总被引:1,自引:1,他引:1  
在前角测量了30MeV/u 40Ar+159Tb反应中两裂片符合下的轻粒子和复杂碎片,利用线性动量转移和总横向动量方法对三体符合事件进行了碰撞参数分类. 实验结果表明,在中心碰撞中复杂碎片主要来自于平衡类靶核的统计发射,并伴随有非平衡中途成份;而周边碰撞中前角区复杂碎片主要来自于弹核碎裂成份. 在半中心碰撞中则存在类弹、类靶和中途三种成份.  相似文献   
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