新型噻吩查尔酮衍生物的合成及其初步抗炎活性研究

查尔酮及其衍生物是一类广泛存在于多种药物植物中的1,3-二苯基丙烯酮化合物,大多具有良好的生物活性。本文以2-噻吩甲醛和4-氟苯乙酮为原料,经3步反应,以较高收率合成了6个未见文献报道的哌嗪取代噻吩查尔酮衍生物(3a~3f),其结构经¹H NMR, ¹³C NMR和HR-MS(ESI)表征。以地塞米松作阳性对照,采用细菌脂多糖诱导小鼠巨噬细胞Raw 264.7炎症模型对3a~3f的体外抗炎活性进行了初步测试。结果表明：化合物3d和3e能有效抑制炎症因子NO的生成（IC₅₀分别为15.24 μM和19.05 μM）。     

分数因子和分数哈密顿图

本文介绍了图的分数方面,将图中基于整数的定义和变量转化为分数形式．介绍了分数图论的一些新结果,特别是关于分数因子和分数哈密顿图的新结果,其中包括了作者最近得到的一些关于分数(g,f)-因子的若干结果．进而,提出了还没有解决的几个新问题．     

荧光体CaSO_4∶Eu的近紫外发光性质

CaSO4∶Eu是一种人们早已较为熟知的发光材料,由于其优异的热释发光特性而被广泛应用于辐射剂量学方面。近年来由于崭新的光致发光液晶显示模式的出现,人们又对其近紫外发射特性产生了极大兴趣。考察了CaSO4∶Eu的发光特性和材料的各种制备方法,以及制备条件对发光性能的影响,特别是对其近紫外发射性能的影响。实验表明,对于还原彻底、结晶良好的样品,激活剂Eu几乎全部以二价铕离子的形式存在,是一种很好的近紫外发射材料。该材料能被低压汞蒸气放电辐射有效激发,其发射带的峰值在386 nm附近,随Eu的掺杂浓度不同而略有差异,半峰全宽约为16 nm,基本满足了近紫外发射的要求,可应用于光致发光液晶显示器件的背照明光源中。     

尼美舒利联合5-Fu对胃癌细胞BGC-823的抗癌作用研究

目的 :研究尼美舒利 (Nimesulide)合用 5 -Fluorouracil(5 -FU)对人胃癌细胞株BGC -82 3的生长抑制作用 ,判断联合用药的效果。方法 :采用MTT法、中效原理等测定药物的体外杀伤作用 ,进行联合用药分析。结果 :尼美舒利合用 5 -FU能显著抑制BGC -82 3的生长 ,当抑制率为 10 -95 %时 ,两药合用时合用指数 (CI) <1,为协同作用 ,使用药浓度减少 1-10倍。结论 :尼美舒利联合 5 -FU能显著增加单用其中一种药物对人胃癌细胞株BGC -82 3的抑制作用 ,两药联合应用时具有较好的协同作用。     

NaGdF4:Yb3+,H03+与GdF3:Yb3+,H03+纳米材料的合成、形貌控制与发光性质

采用水热法通过调控n(F-):n(Ln3+),pH值以及n(Citrate):n(Ln)等一系列反应条件,合成了六方相的NaGdF4:Yb3,ho3+与GdF3:yb3+,Ho3+纳米上转换材料,实现了形貌的可控合成.利用X射线粉末衍射(XRD),场扫描电子显微镜(SEM)以及发光光谱等手段对产物的物相结构、形貌和荧光...     

高效液相色谱法测定卷烟醋酸纤维滤棒中甲醛、乙醛和丙酮的含量

建立了高效液相色谱法同时测定卷烟醋酸纤维滤棒中甲醛、乙醛和丙酮含量的方法,采用Acclaim(R)Explosive E2 C18色谱柱,流动相为乙腈/水梯度洗脱,流速为0.5 mL/min,检测波长为352 nm,对甲醛、乙醛和丙酮的分析取得满意的效果.甲醛、乙醛、丙酮的回收率分别为95.3％～105.6％、86.1...     

Novel in-band OSNR monitoring method based on polarization interference

We propose a novel in-band optical signal-to-noise ratio （OSNR） monitoring method based on polarization interference. The method realizes a monitoring accuracy of ±0.5 dB within the range of 9 34 dB. Our results indicate that the proposed method is transparent to bitrate and modulation format, as well as independent of polarization mode dispersion and chromatic dispersion.     

Growth and characterization of straight InAs/GaAs nanowire heterostructures on Si substrate

Vertical InAs/GaAs nanowire (NW) heterostructures with a straight InAs segment have been successfully fabricated on Si (111) substrate by using AlGaAs/GaAs buffer layers coupled with a composition grading InGaAs segment. Both the GaAs and InAs segments are not limited by the misfit strain induced critical diameter. The low growth rate of InAs NWs is attributed to the AlGaAs/GaAs buffer layers which dramatically decrease the adatom diffusion contribution to the InAs NW growth. The crystal structure of InAs NW can be tuned from zincblende to wurtzite by controlling its diameter as well as the length of GaAs NWs. This work helps to open up a road for the integration of high-quality III-V NW heterostructures with Si.     

Growth and characterization of GaAs/In_χGa_(1-χ)As/GaAs axialnanowire heterostructures with symmetrical heterointerfaces

We report on the Au-assisted vapour-liquid-solid(VLS) growth of GaAs/InxGa1-xAs/GaAs(0.2 ≤ x ≤ 1) axial double-heterostructure nanowires on GaAs(111) B substrates via the metal-organic chemical vapor deposition(MOCVD) technique.The influence of the indium(In) content in an Au particle on the morphology of nanowires is investigated systematically.A short period of pre-introduced In precursor before the growth of InxGa1-xAs segment,coupled with a group III precursor interruption,is conducive to obtaining symmetrical heterointerfaces as well as the desired In/Ga ratio in the InxGa1-xAs section.The nanowire morphology,such as kinking and tapering,are thought to be related to the In composition in the catalyst alloy as well as the VLS growth mechanism.