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991.
This paper establishes the generalized Poynting theorem for the electrodynamics of deformable media with a view to shedding some light on the detailed mechanism of energy transfer between the electromagnetic field and the deformable media. Global field equations are chosen as the starting point and specialized forms of the theorem are derived based on the special postulates for the electromagnetic body force.  相似文献   
992.
New porphyrin–Schiff base conjugates bearing one (6) and two (7) basic amino groups were synthesized by condensation between tetrapyrrolic macrocycle-containing amine functions and 4-(3-(N,N-dimethylamino)propoxy)benzaldehyde. This approach allowed us to easily obtain porphyrins substituted by positive charge precursor groups in aqueous media. These compounds showed the typical Soret and four Q absorption bands with red fluorescence emission (ΦF ~ 0.12) in N,N-dimethylformamide. Porphyrins 6 and 7 photosensitized the generation of O2(1Δg) (ΦΔ ~ 0.44) and the photo-oxidation of L-tryptophan. The decomposition of this amino acid was mainly mediated by a type II photoprocess. Moreover, the addition of KI strongly quenched the photodynamic action through a reaction with O2(1Δg) to produce iodine. The photodynamic inactivation capacity induced by porphyrins 6 and 7 was evaluated in Staphylococcus aureus, Escherichia coli, and Candida albicans. Furthermore, the photoinactivation of these microorganisms was improved using potentiation with iodide anions. These porphyrins containing basic aliphatic amino groups can be protonated in biological systems, which provides an amphiphilic character to the tetrapyrrolic macrocycle. This effect allows one to increase the interaction with the cell wall, thus improving photocytotoxic activity against microorganisms.  相似文献   
993.
1IntroductionFibergratingpairsystemhasbenwidelyusedinthetechniqueofpulsecompresion.Thepropagationandtransformationofpulsesth...  相似文献   
994.
Cu、Zn-SOD酶模型化合物催化O-2歧化作用的研究   总被引:1,自引:0,他引:1  
本文采用NBT法,利用721分光光度计,在pH=7.8的条件下,测定了前文所合成的含N、O的S的Schiff碱及其铜(Ⅱ)、锌(Ⅱ)配合物催化O2^-歧化的活性,并探讨了平均抑制率与浓度的关系。  相似文献   
995.
Two new types of tripodal Cu(Ⅱ) and Zn(Ⅱ) complexes with 8-methyquinoline as an arm were synthesized. Their compositions and structures were characterized by elemental analyses, conductitivies, IR, MS and NMR spectra. Moreover the electronic spectra, room temperature magnetic susceptibility and electrical chemistry of the complexes have been discussed.  相似文献   
996.
水杨醛缩L-天冬氨酸过渡金属配合物的合成及表征   总被引:18,自引:0,他引:18  
合成了新的水杨醛天冬氨酸席夫碱配体及其铜、锌、钴、镍配合物,并利用元素分析、摩尔电导、热分析、红外光谱、电子光谱及顺磁共振等手段进行表征,确定配合物的化学组成为K[ML]·nH2O,式中L=C11H7NO, M=Cu2+、Zn2+、Co2+、Ni2+,相应地n=2、2、3、7/2。  相似文献   
997.
A thermodynamic study is reported for the coordination reaction of ZnT ( m-X)PP derivatives (X = NO2, Cl, OCH3, H or CH3) with various ligands L (L= imidazole (Im), 2-methylimidazole (MeIm), clotrimidazole (CIM), imidazole-4-carboxaldehyde (4-CHOIm), unsymmetrical tetradentate copper Schiff base, CuIm(p-Cl), CuIm(p-Br), and nickel Schiff base, NiIm(p-Cl)), in dichloromethane solvent. Conversion of the four-coordinated ZnT( m-X)PP to the five-coordinated species is followed and isosbestic behavior is exhibited in the region among 450 and 700 run. The reaction of a copper(Ⅱ) or nickel(Ⅱ) imidazolate Schiff base with ZnT(m-X)PP results in the formation of an imidazolate bridged heterobinuclear complex. The stoichiometric number is unity for all axial ligands. The equilibrium constants were determined using the β band of ZnT( m-X)-PP in the 293-308 K range by the method of Rose and Drago. It increases with decrease in temperature, and △H0 < 0, △S0 < 0. The stronger the nucleophilic ability of the axial  相似文献   
998.
Five hydrotalcites with Mg/Al molar ratio range of 3-15 were prepared. The structure and basicity of Mg-Al mixed oxides (Mg(Al)O) transformed from hydrotalcites were investigated by TPD, XPS, XRD, FT-IR and NMR techniques. The results of elemental analysis and XPS indicate that Al is enriched in the surface regions of Mg(Al)0, and its amount increases with the Mg/Al molar ratio and the calcination temperature. 27Al-MAS-NMR results show that Al exists in two chemical environments: tetrahedral aluminium (Al(t)) and octahedral aluminium (Al(o)) in Mg(Al)O. The amount of Al(t) increases with the Mg/Al molar ratio and the calcination temperature. It is assumed that Al(t) may be mainly from the surface Al. Temperature-programmed desorption (TPD) of CO2 shows that the number of basic sites of Mg(Al)O samples increases with the Mg/Al molar ratio, and the maximum number of basic sites is obtained for hydrotalcite calcined at 773 K. Infrared spectra of adsorbed CO2 and B(OCH3)3 reveal that there are two kinds of  相似文献   
999.
In this paper, the translation of the Lax pairs of the Levi equations is presented. Then a symmetry constraint for the Levi equations is given by means of binary nonlinearization method. The spatial part and the temporal parts of the translated Lax pairs and its adjoint Lax pairs of the Levi equations are all constrainted as finite dimensional Liouville integrable Hamiltonian systems. Finally, the involutive solutions of the Levi equations are presented.  相似文献   
1000.
61.IntroductionSincethepoineeringworkofZariskil1o]therehavebeenmanypaperspublishedonthemodulinumberofplanecurvesingUlaritiesl5-9].TheproblemhowtocomputethemodulinumberattractsmWattentions[3'6-1o1.Asfarastheauthors'knowledgethemostgener-aJizedalgorithmistheworkof[3]whichdependsonthedivisiontheoremin[1,2].HerewegivealinearalgebraicproofoftheBriancon-Granger-Maisonobe,stheoremlwhichavoidstheDivisiontheorem.Sincethedivisiontheoremonlyholdsindimension2,itseemsquitehopefUlthattheproofherewil1beg…  相似文献   
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