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市售试剂锌原卟啉具有可提供配位结合位点的中心金属原子、可提供氢键和电荷结合位点的两个羧酸基,卟吩环独特的吸光及发光特性使其成为一种有潜力的分子识别功能试剂.本文以紫外光谱研究了锌原卟啉在水溶液中对组胺的分子识别;通过1↑H核磁共振及其NOE测定方式对锌原卟啉分子中各质子的核磁共振位移进行了归属,研究了氘代DMSO中主客体的结合模式.通过分子轨道理论计算验证了卟吩环外两个羧酸基与组胺氨基形成的两对氢键、组胺咪唑环上的N与锌原卟啉的Zn的配位作用是主客体结合驱动力这一观点. 相似文献
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采用磁控溅射技术制备了铒掺杂的氢化非晶硅(a-Si∶H(Er))样品.进一步通过200—500℃温度递增的后退火处理,获得了不同的Si悬挂键(Si-DBs)密度,并在此基础上研究了Si-DBs密度改变对其Er光荧光(Er-PL)的影响.退火温度低于350℃时,Er-PL强度持续增加,但Si-DBs密度的变化显得较复杂;350℃以上时,Er-PL强度随Si-DBs密度的增加而减小.在200—250℃的退火温度范围内,Si-DBs是由于结构弛豫而减少;在250—500℃的退火温度范围内,可能由于Si—H键的断
关键词:
氢化非晶硅
铒掺杂
Si悬挂键
光荧光 相似文献
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Small change in chemical structure of discotic liquid crystals can cause big difference in their mesomorphism. Replacing of the alkoxy peripheral chains of triphenylene by oxygen-atom containing ester chains would result in novel mesomorphism. A series of mixed tail triphenylenes containing propoxyacetyloxy and alkoxy, abbreviated as C18H6(OCnH2n+1)3(OCOCH2OC3H7)3, n=4-8, and hexa(propyloxyacetyloxy)triphenylene, C18H6(OCOCH2OC3H7)6 were synthesized. Thermal gravimetry analysis (TGA) of three discogens showed that they had good thermal stability till 350 ℃. The mesomorphism was investigated through differential scanning calorimetry (DSC) and polarized optical microscopy (POM). The preliminary X-ray diffraction (XRD) results of one compound showed that it exhibited ordered hexagonal columnar (Colho) mesophase. These mixed tail triphenylene derivatives possessed much stable Colho mesophase and wider mesophase ranges than their hexaalkoxytriphenylene C18H6(OR)6 and hexaalkanoyloxytriphenylene C18H6(OCOR')6 analogues. The asymmetrical compounds 2,6,11-trialkoxy-3,7,10-tri(2-propyloxyacetyloxy)triphenylenes with n=5-8 displayed higher clearing points and wider temperature ranges than their symmetrical isomers 2,6,10-trialkoxy-3,7,11-tri(2-propyloxyacetyloxy)- triphenylenes, while C18H6(OCOCH2OC3H7)6 had the highest clearing point due to the β-oxygen-atom effect. 相似文献
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对Eu1-xSrxMnO3 (x=0.4, 0.5, 0.6, 0.7) 体系的磁结构进行了系统的研究. 通过核磁共振实验, 磁化测量, 并结合电输运测量结果表明, Sr的掺入使得 EuMnO3反铁磁母相中出现铁磁相. 铁磁相和反铁磁相的竞争导致样品在低温下的自旋玻璃行为.分析认为, Eu0.4Sr0.6MnO3和Eu0.3Sr0.7MnO3的磁结构在低温下呈现更加复杂的特征, 主要源于铁磁团簇的形成以及无序相的存在. 相似文献
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