首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   18篇
  免费   1篇
  国内免费   1篇
化学   19篇
物理学   1篇
  2021年   1篇
  2017年   1篇
  2008年   1篇
  2006年   1篇
  2005年   1篇
  2003年   1篇
  2002年   1篇
  2000年   1篇
  1999年   4篇
  1998年   1篇
  1994年   2篇
  1993年   3篇
  1992年   2篇
排序方式: 共有20条查询结果,搜索用时 15 毫秒
1.
本文基于抗坏血酸还原铁(Ⅲ)-邻菲啰啉为红色铁(Ⅱ)-邻菲啰啉,建立了流动注射分光光度法测定药品中抗坏血酸的方法。本法体系简单,操作方便、快速,标准加入试验的回收率为92~103%。  相似文献   
2.
合成了双亲性的铕、铽-邻苯二甲酸正十四醇单酯-邻菲咯啉三元混配配合物,用红外光谱及差热-热重谱进行了表征。考察了发光性能。研究了它们在空气-水界面上的单分子膜行为,结果表明均具有良好的成膜行为。  相似文献   
3.
A novel sol–gel derived hybrid material (classed as Eu-DBM-Si) covalently grafted with Eu(DBM-OH)3·2H2O (where DBM-OH = o-hydroxydibenzoylmethane) was prepared through the primary β-diketone ligand DBM-OH. All the synthesized ligands were characterized by 1H NMR, elemental analyses and Fourier transform infrared spectra (FTIR). The resultant Eu-DBM-Si material exhibited good transparent and homogenous property. Compared to the Eu-DBM hybrid prepared by physically doped silicon dioxide with Eu(DBM-OH)3·2H2O, the Eu-DBM-Si hybrid presented more efficient ligand-to-Eu3+ energy transfer and a significant improvement in the measured emission quantum yield. Furthermore, the photophysical properties of these hybrid materials, such as the photoluminescence (PL) spectra, PL intensities, symmetry properties, lifetime decays, and Judd-Ofelt parameters were also investigated in detail.  相似文献   
4.
IntroductionThelow-temperatureprocessingofthesol-gelmaterialmakesitpossibletoentraporganicspecieseasilywithinarigidglassmatri...  相似文献   
5.
A novel mesoporous SBA-15 type of hybrid material (phen-SBA-15) covalently bonded with 1,10-phenanthroline (phen) ligand was synthesized by co-condensation of tetraethoxysilane (TEOS) and the chelate ligand 5-[N,N-bis-3-(triethoxysilyl)propyl]ureyl-1,10-phenanthroline (phen-Si) in the presence of Pluronic P123 surfactant as a template. The preservation of the chelate ligand structure during the hydrothermal synthesis and the surfactant extraction process was confirmed by Fourier transform infrared (FTIR) and (29)Si MAS NMR spectroscopies. SBA-15 consisting of the highly luminescent ternary complex Eu(TTA)(3)phen (TTA = 2-thenoyltrifluoroacetone) covalently bonded to a silica-based network, which was designated as Eu(TTA)(3)phen-SBA-15, was obtained by introducing the Eu(TTA)(3).2H(2)O complex into the hybrid materials via a ligand exchange reaction. XRD, TEM, and N(2) adsorption measurements were employed to characterize the mesostructure of Eu(TTA)(3)phen-SBA-15. For comparison, SBA-15 doped with Eu(TTA)(3).2H(2)O and Eu(TTA)(3)phen complexes and SBA-15 covalently bonded with a binary europium complex with phen ligand were also synthesized, and were named SBA-15/Eu(TTA)(3), SBA-15/Eu(TTA)(3)phen, and Eu-phen-SBA-15, respectively. The detailed luminescence studies on all the materials showed that, compared with the doping sample SBA-15/Eu(TTA)(3)phen and binary europium complex functionalized sample Eu-phen-SBA-15, the Eu(TTA)(3)phen-SBA-15 mesoporous hybrid material exhibited higher luminescence intensity and emission quantum efficiency. Thermogravimetric analysis on Eu(TTA)(3)phen-SBA-15 demonstrated that the thermal stability of the lanthanide complex was evidently improved as it was covalently bonded to the mesoporous SBA-15 matrix.  相似文献   
6.
采用两步溶胶-凝胶过程制备了含铕的三元配合物的凝胶。荧光激发光谱证实于SiO2基质中原位合成了铕的配合物。含铕配合物的杂化材料发出铕的特征荧光,与相应的纯配合物溶于乙醇相比,铕离子具有较长的荧光寿命。  相似文献   
7.
卡尔曼滤波法解析严重重叠的荧光峰   总被引:2,自引:2,他引:2  
张晶玉  杨金夫 《分析化学》1993,21(10):1152-1155
锌、铝同7-碘-8羟基喹啉-5-磺酸-溴化十六烷基三甲铵形成的络合物荧光光谱严重重叠,分离度仅为0.26。本文以该体系为例,着重考察了卡尔曼滤波法解析谱峰严重重叠体系的潜力。结果表明,在锌、铝络合物峰值处,当铝络合物的荧光强度小于锌络合物的荧光强度时,二者均可得到满意的分析结果,当铝络合物的荧光强度大于锌络合物的荧光强度时,锌的分析结果显著变差。在此情况下,用卡尔曼滤波法处理同步荧光光谱数据,分析  相似文献   
8.
Ternary europium complexes with thenoyltrifluoroacetone (TTA) and phenanthroline (phen) were incorporated into SiO2/polymer matrix by a sol-gel method. The gels exhibit the characteristic emission bands of europium ion. In addition, Eu3+ presents a longer fluorescence lifetime in gel than in the corresponding pure complex powder. Concentration effects on the luminescence intensity were investigated. The reasons that are responsible for above results are also discussed in the context.  相似文献   
9.
Reactions of pyrazine‐2,3‐dicarboxylic acid (H2pzdc), cobalt nitrate and lanthanide (Ln) oxide under hydrothermal conditions result in four new 3d‐4f heterometal coordination polymers, namely, [Ln2Co(pzdc)4(H2O)6] · 2H2O [Ln = La ( 1 ), Pr ( 2 ), Eu ( 3 ) and Gd ( 4 )]. All compounds were characterized by elemental analysis, infrared spectroscopy, thermal gravimetric analysis, and X‐ray diffraction. The compounds exhibit a three‐dimensional (3D) brick‐like structure with rectangular‐shaped nano‐scale channels along a axis direction, made up of wave‐like layers containing [Ln(pzdc)]+ units, which are connected by one‐dimensional (1D) chain of [Co(pzdc)2]2–. The catalytic properties of compounds 1 and 3 were investigated in the synthesis of cyanohydrins at room temperature under solventless conditions. They showed similar catalytic activities with very high conversions of benzaldehyde and high selectivity towards cyanohydrin. The control experiment without addition of the coordination polymers only reached 16 % conversion. Other aldehydes could also be converted totally under shorter reaction times also with very high selectivities for the corresponding cyanohydrins. Compound 1 could also be recycled in another catalytic cycle.  相似文献   
10.
本文以荧光光谱重叠的罗丹明B和罗丹明6G二组分混合体系为例考察了卡尔曼滤波法处理荧光光谱数据与荧光光谱法中的同步荧光技术和数值导数方法对该体系荧光光谱的解析能力。由于该体系中二组分谱峰重叠程度较轻,采用同步荧光技术可以将二者完全分开。用卡尔曼滤波法处理常规荧光光谱数据也获得了令人满意的结果。但该体系的一阶导数光谱不仅不能将二者分开,而且灵敏度降低,不及前二种方法。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号