排序方式: 共有172条查询结果,搜索用时 15 毫秒
101.
设计并合成了新型尾式氨基酸卟啉5-(Trt-组氨酸酰胺基苯基)-10,15,20-三苯基卟啉(Trt-His-NH2-TPP,1)及其金属卟啉配合物(Zn,Co,Fe,Mn,分别标记为2~5).通过元素分析、核磁共振氨谱、质谱、紫外-可见光谱和红外光谱等对化合物进行了表征,研究了它们的荧光性质,并通过理论模拟研究了其最... 相似文献
102.
以聚乙烯吡咯烷酮/硝酸镧-乙酸钴-乙酸镍(PVP/LCN)为前驱体, 采用静电纺丝法, 经预氧化、碳化, 制得双钙钛矿La2CoNiO6无机纳米纤维超级电容器电极材料. 利用X射线衍射(XRD)、扫描电镜(SEM)和透射电镜(TEM)对其形貌和结构进行表征. 结果表明, 纤维由菱形结构的La2CoNiO6纳米颗粒相互连接而成, 呈链状空间网状结构. 循环伏安(CV)、恒流充放电(CP)和循环寿命测试表明, La2CoNiO6纳米纤维电极材料在三电极体系中, 电流密度为0.25 A·g-1时, 比电容值达335.0 F·g-1; 在对称型双电极体系中, 电流密度为0.25 A·g-1时, 比电容值可达到129.1 F·g-1,表现出良好的电容性能. 相似文献
103.
激发态双质子转移反应长期困扰着理论和实验科学家并成为了一个悬而未决的热点问题. 本文利用完全活化空间自洽场方法及其二阶微扰理论(MS-CASPT2//CASSCF)系统地研究了典型体系1,8-二羟基-2-萘甲醛(DHNA)的激发态双质子转移反应以及相关的激发态弛豫过程. 在MS-CASPT2//CASSCF水平下,本文优化了三个能量相近但结构不同的S1态互变异构体,即S1-ENOL、S1-KETO-1和S1-KETO-2,以及两个关键的S1/S0锥形交叉点结构,即S1S0-KETO-1和S1S0-KETO-2. 其中,两个极小点S1-KETO-1和S1-KETO-2与实验上观测到的双荧光发射现象密切相关. 本文还利用MS-CASPT2//CASSCF方法计算了双质子转移反应的二维势能面以及从极小点到交叉点结构的线性内插路径;相应计算结果证实了DHNA体系具有分步的激发态双质子转移机制. 具体来说,从S1-ENOL到S1-KETO-1的第一个质子转移过程是无能垒的,而从S1-KETO-1到S1-KETO-2的第二个质子转移过程则需要克服一个大约6.0 kcal/mol的能垒. 此外,由于从S1-KETO-1 (S1-KETO-2)到S1S0-KETO-1 (S1S0-KETO-2)的线性内插路径显示DHNA体系需要翻越一个约为12.0 kcal/mol的能垒,因此DHNA体系将在S1态上停留一段时间并发生双荧光发射现象. 当然,S1/S0锥形交叉点也会促使DHNA体系从S1态内转换到S0态,而这会一定程度上降低DHNA体系发射荧光的效率. 可以通过限制C5-C8-C9-O10二面角旋转来降低体系的内转换效率,进而提高DHNA体系的发光效率. 本工作不仅有助于理解激发态双质子转移机制,还有助于设计具有优异发光性能的新型分子材料. 相似文献
104.
105.
Capillary electrophoresis with sodium dodecyl sulfate (CE-SDS) is a common analytical technique for investigating the purity and molecular size heterogeneity of monoclonal antibody (mAb) drugs. In reducing CE-SDS analysis of mAb-A, the light chain (LC) peak exhibited severe tailing, seriously affecting the purity analysis. The purposes of this investigation are to clarify the source of tailing and develop a more appropriate CE-SDS method to eliminate LC tailing. The degree of LC tailing was closely related to the mAb concentration, SDS concentration, and injection amount, and more hydrophobic detergents, such as sodium hexadecyl sulfate (SHS) and sodium tetradecyl sulfate (STS), could be used instead of SDS to obtain better peak shapes. The results also indicated that the tailing was caused by the binding problem associated with SDS, and SHS/STS could provide a more stable and uniform complexation for the LC. In summary, the method we developed successfully eliminated the LC tailing and provided a robust characterization of mAb-A in reducing CE-SDS analysis. 相似文献
106.
107.
The effect of cubic potentials on discrete breathers in a mixed Klein-Gordon/Fermi-Pasta-Ulam chain
下载免费PDF全文
![点击此处可从《中国物理 B》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Nonlinearity has a crucial impact on the symmetry properties of dynamical systems.This paper studies a onedimensional mixed Klein-Gordon/Fermi-Pasta-Ulam diatomic chain using the expanded rotating plane-wave approximation and numerical calculations to determine the effect of cubic potentials on the symmetry properties of discrete breathers in this system.The results will be very useful to researchers in the field of numerical calculations on discrete breathers. 相似文献
108.
Xu BB Zhang R Liu XQ Wang H Zhang YL Jiang HB Wang L Ma ZC Ku JF Xiao FS Sun HB 《Chemical communications (Cambridge, England)》2012,48(11):1680-1682
Silver microflower arrays constructed by upright nanoplates and attached nanoparticles were fabricated inside a microfluidic channel, thus a robust catalytic microreactor for allowing in situ SERS monitoring was proposed. On-chip catalytic reduction shows that the silver microflowers have high catalytic activity and SERS enhancement. 相似文献
109.
A one-pot procedure for the synthesis of 5-benzoyl-8H-phthalazino[1,2-b]quinazolin-8-ones is achieved by an iodine-catalyzed reaction of 2-aminobenzohydrazides and 2-alkynylbenzaldehydes in good yields. The salient feature of this strategy is a domino type process including a condensation, addition, hydroamination, and a noteworthy benzyl automatic oxidation by oxygen under metal-catalyst-free conditions. 相似文献
110.