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1.
Four Cu2+ complexes of salicylidene-amino acid Schiff base with 1,10-phenanthroline(Phen) or 2,2’- bipyridine(Bipy) were successfully intercalated in interlayer galleries of Mg/Al-NO3-layered double hydroxide(LDH) by the swelling-restored method.The hybrids were characterized by elemental analysis,X-ray diffraction,FT-IR spectra,UV-vis DRS,TG-DTA and SEM observation.Good protection of the complexes by LDH in neutral and weak acidic solutions was revealed by UV spectra,cyclic voltammograms and luminescence spectra.  相似文献   
2.
The measurement of the two-mode squeezed vacuum generated in an optical parametric amplifier (OPA) was performed with photon number resolving multipixel photon counters (MPPCs). Implementation of the MPPCs allows for the observation of noise reduction in a broad dynamic range of the OPA gain, which is inaccessible with standard single photon avalanche photodetectors.  相似文献   
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Based on the quantum confinement-luminesecence center model,to ensembles of spherical silicon nanocrystals (nc-Si)containg two kinds of luminescence centers(LCs) in the SiOx layers surrounding the nc-Si,the relationship between the photolumincescence(PL) and the thickness of the SiOx layer is studied with the excitation energy flux density as a parameter.When there is no SiOx layer surrounding the nc-Si,the electron-heavy hole pair can only recombine inside the nc-Si,then the PL bluehift with reducing particle sizes roughly accords with the rule predicted by the quantum confinement model of Canham.When there presences a SiOx layer,some of the carriers may tunnel into it and recombine outside the nc-Si at the LCs to emit visible light.The thicker the SiOx layer is,the higher the radiative recombination rate occurred outside the nc-Si will be.When the central Scale of the nc-Si is much smaller than the critical scale,the radiative recombination rate outside the nc-Si dominates,and visible PL will be possible for some nc-Si samples with big average radius,greater than 4nm,for example.When there is only one kind of LC in the SIOx layer,the PL peak position does not shift with reducing particle sizes.All these conclusions are in accord with the experimental results.When there are two or more kinds of LCs in the SiOx layer,the PL peak position energy and intensity swing with reducing particle sizes.  相似文献   
4.
Jian  Ning-Ge  Liang  Si-Hui  Cao  Jian-Kun  Di  Qian-Nan  Kang  Kai  Xu  Qian 《Mikrochimica acta》2019,186(12):1-13
Microchimica Acta - A core-shell structured magnetic covalent organic frameworks of the type Fe3O4@COFs was prepared by using the Fe3O4 nanoparticles as magnetic core, and...  相似文献   
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A series of novel indole derivatives were designed and synthesized and their inhibitory activity against B-Raf and HepG2 cell were also described. Among them, compounds 7a and 7b exhibited excellent potency, which showed the potential for further research as lead compounds.  相似文献   
7.
Zhou  Yong-Hong  Xu  Yun  Xue  Zu-Qian  Shi  Jun-Qing  Su  Yue  Sun  Mei-Ling  Wang  Si-Hui  Wang  Long-Long  Wang  Qing-Qing  Wei  Yuan-Jie 《Transition Metal Chemistry》2020,45(5):353-362
Transition Metal Chemistry - Four metal–organic coordination complexes, namely {[Zn(SIP)(mbi)2]·(Hmbi)·(H2O)2}n (1), {[Cd3(SIP)2(bbhb)3(H2O)4]·(H2O)2}n (2),...  相似文献   
8.
黄凯  王思慧  施毅  秦国毅  张荣  郑有炓 《物理学报》2004,53(4):1236-1242
从量子限制发光中心模型出发,计算了纳米硅的光致发光(PL)特征与发光中心间的关系. 研究发现,纳米硅与发光中心间的内电场对载流子复合率及峰位振荡有着十分重要的影响. 在2—5 nm的尺寸范围内,纳米硅发光中心上的载流子复合概率远大于内部复合概率,仅需考虑发光中心上的载流子复合发光. 还发现发光中心与纳米硅粒子间的内电场对于纳米硅的发光峰位振荡有着显著的影响.发光中心与纳米硅粒子间的内电场的存在会显著减小纳米硅粒子的内部发光效率以及外部相应发光中心上的发光强度,使得纳米硅PL谱的峰位随纳米晶粒尺寸变化而发生 关键词: 内电场 纳米硅 光致发光 量子限制发光中心  相似文献   
9.
以新课标高中化学中醇的化学性质和酯的水解反应知识为切入点,介绍一种符合绿色化学理念的丙二醇制备法——甘油催化氢解的基本原理和3种主要机理,供一线教师用于高中化学教学实践。  相似文献   
10.
针对研究生大型仪器实验教学存在的参与度低、教学效果不佳等问题,以液质联用仪实验教学为例,引入问题导向学习模式,围绕劣构的科研案例问题来设计教学过程,以学生为中心,以问题为学习的起点,使学生主动去寻求问题解决的方法,提高了学生的自主学习能力、知识掌握水平以及知识迁移能力;同时,为系统评价大型仪器实验教学的效果,给进一步教学改革提供数据参考,从观察学生的课堂表现、调查学生的课堂感受、考察学生的课程任务完成情况等3个方面入手,探索了量化评价实验教学效果的指标。  相似文献   
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