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961.
A series of Ru(N–N)2(dcbp or mcmabp) complexes were synthesized where N-N represents a diimine ligand, dcbp is 4,4-dicaboxylic 2,2-bipyridine, and mcmabp is 4,4-2,2-bipyridine monocarboxy amide. The N-N ligand was either 2,2-bipyridine (bpy), 4,4-dimethyl-2,2-bipyridine (dmbp), or 4,4,5,5-tetramethyl-2,2-bipyridine (tmbp). We observed a red shift in both the absorption and emission with the presence of dcbp in the mixed ligand complex when compared to Ru(bpy)3. Conversion of one of the carboxylic groups in dcbp to amide resulted in further red shifts. A red shift in the absorption and the emission was also observed with increasing numbers of electrons donating methyl substitutions on bpy. The lifetimes of the complexes decreased as expected with the red shift emission. The tris heteroleptic Ru (tmphen)(tmbp)(dcbp or mcmabp) were the most red-shifted among the complexes. Because of the red shift in the absorption, the maxima in the fundamental anisotropies of the mixed ligand Ru complexes are now coincident with the maxima in the absorption. Overall we have been able to make an Ru complex which emits at about 700 nm in all aqueous environment and has a lifetime of about 220 ns. 相似文献
962.
Howard E. Brandt 《Foundations of Physics Letters》1991,4(6):523-536
The universal upper limit on attainable proper acceleration relative to the vacuum imposes restrictions on possible structures in the spacetime tangent bundle. Various features of the differential geometry of the spacetime tangent bundle are presented here. Also, a modified Schwarzschild solution is obtained, and the associated gravitational red shift is calculated. 相似文献
963.
964.
目的:研究卡瓦内酯对小鼠抗缺氧能力的影响。方法:耐急性缺氧能力、镇静作用和肌内松驰作用选用小鼠进行观察,红细胞和血红蛋白的分析按常规方法进行。结果:卡瓦内酯级明显提高小鼠耐急性缺氧能力,同时具有镇静和肌肉松驰作用,但未见到红细胞数和血红蛋白含量的增加。结论:卡瓦内酯能提高小鼠耐急性缺氧能力,与红细胞数量和血红蛋白的含量无关。可能的机制是降低了小鼠的耗氧量,从而提高了小鼠的耐急性缺氧的能力。 相似文献
965.
966.
967.
Yu?DuanEmail author Jiang?Li Yi?Zhao Gang?Cheng Jingying?Hou Shiyong?liu 《Optical and Quantum Electronics》2005,37(12):1121-1127
Efficiencies of up to 7.81 cd/A and brightness of 8843 cd/m2 are obtained based on green–yellow phosphorescent material, fac 4, 4′-bi (tert-butyl)-2, 2′-bipyridine Re(CO)3Cl[(Bu t bpy)Re(CO)3Cl] doped into 4,4′-N,N′-dicarbazole-biphenyl (CBP) host. We also fabricate high-efficiency red devices by introduction of (Butbpy)Re(CO)3Cl as a sensitizer, and the undoped ultrathin layer 4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) as fluorescent acceptor. Förster energy of triplet and singlet are efficient due to appropriate overlap between emission spectrum of (Bu t bpy)Re(CO)3Cl and absorption spectrum of DCJTB. 相似文献
968.
利用Na2CO3作为助熔剂,采用高温固相反应方法制备了三价铕离子激活的Gd2Mo3O9红色荧光粉。利用XRD和荧光光谱,研究了助熔剂的量、制备时的温度以及激活剂Eu3+的浓度对荧光粉的晶体结构和发光性能的影响。测试结果表明,这种新型的荧光粉可以被紫外光280nm,近紫外光395nm和蓝光465nm有效激发,发射主峰位于613nm,并且证明Eu3+离子在晶体结构中占据了非反演对称中心的位置。395,465nm的吸收与目前广泛应用的紫外和蓝光LED芯片的输出波长相匹配。因此,这种荧光粉是一种可能应用在白光LED上的红色荧光粉材料。 相似文献
969.
970.
Yu. V. Kruchenok N. A. Nemkovich V. G. Pivovarenko A. N. Rubinov 《Journal of Applied Spectroscopy》2002,69(3):371-379
The intramolecular transfer of a proton in 4amine derivatives of 3hydroxyflavone was investigated in binary solvents, which are a mixture of polar and nonpolar liquids. The dependence of the efficiency of the intramolecular transfer of a proton in an excited state on the frequency of the exciting light has been revealed, which is due to the spectral inhomogeneity of the molecules of fluorophors in binary solvents. A scheme of the processes of intramolecular transfer of a proton and an electron in 4amine derivatives of 3hydroxyflavone is suggested. 相似文献