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151.
研究了新显色剂3,5-二(1-羧基-4,5-二甲氧基-2-苯氨基偶氮基)苯甲酸(CDMOBAABA)与铜(Ⅱ)的显色反应。在TritonX-100存在下,于pH9.5的NH3-NH4Cl缓冲介质中,CDMOBAABA与铜(Ⅱ)形成棕红色配合物。试剂与络合物的最大吸收波长分别为450nm和540nm。表观摩尔吸光系数为2.43×105L·mol-1.cm-1。铜(Ⅱ)含量在0—20μg/25mL范围内符合比耳定律。该方法用于铝合金样品中铜的测定,结果与原子吸收光谱法相吻合,相对标准偏差1.89%。 相似文献
152.
We present a potential of which the short-distance part is given by one gluon exchange plus perturbative one- and two-loop corrections and of which the large-distance part exhibits a temperature-dependent constant value. The Schrödinger equation with this temperature-dependent potential yields a temperature dependence of the mesonic quark–antiquark relative-motion wave function and of meson masses. The temperature dependence of the potential, the wave function and the meson masses brings about temperature dependence of cross sections for the nonresonant reactions for , for , for , for , for , for and for . As the temperature increases, the rise or fall of peak cross sections is determined by the increased radii of initial mesons, the loosened bound states of final mesons, and the total-mass difference of the initial and final mesons. The temperature-dependent cross sections and meson masses are parametrized. 相似文献
153.
Based on a hydro-inspired azimuthally symmetric emission function, we analyze the HBT radius Rs and the single-particle transverse momentum spectra in Au+Au collisions measured by the STAR Collaboration at SNN = 200 GeV. The results show that consistent assumptions about transverse density (and/or flow profile) in the calculation of the HBT radius Rs and single-particle spectral analyses play an important role for understanding the size of the freeze-out source. 相似文献
154.
155.
In this paper the equilibrium structure of HCO has been optimized by using density functional theory (DFT)/ B3P86 method and CC-PVTZ basis. It has a bent (Cs, X^2A') ground state structure with an angle of 124.4095 °. The vibronic frequencies and force constants have also been calculated. Based on the principles of atomic and molecular reaction statics, the possible electronic states and reasonable dissociation limits for the ground state of HCO molecule have been determined. The analytic potential energy function of HCO (X^2A') molecule has been derived by using the many-body expansion theory. The contour lines are constructed, which show the static properties of HCO (X^2A'), such as the equilibrium structure, the lowest energies, etc. The potential energy surface of HCO (X^2A') is reasonable and very satisfactory. 相似文献
156.
用水热法合成了基于刚性不对称三氮唑衍生物配体H2ptp (H2ptp=4-(5-(1H-pyrazol-4-yl)-4H-1,2,4-triazol-3-yl)pyridine)的2个Cd(Ⅱ)配合物 {[Cd2(Hptp)2(OAc)2]·7H2O}n (1)和{[Cd(Hptp)Cl(H2O)]·H2O}n (2),并通过元素分析、差热分析、粉末X射线衍射和单晶X射线衍射进行表征。配合物1具有一个梯状的一维结构,在π…π堆积作用下这些一维梯链形成了超分子二维平面。在氢键的连接作用下,客体水分子形成了独特的以双五元水簇为结构单元的水链,这些水链填充在相邻的二维平面之间并通过氢键把二维平面连接成了三维超分子网络。配合物2具有一个新型的二维双层结构,分子间氢键把这些二维平面连成了三维结构。另外,测试了2个配合物的荧光性质。 相似文献
157.
酞菁与TiO2微粒间的光诱导电子转移相互作用 总被引:2,自引:0,他引:2
带有负电荷取代基的四磺化酞菁化合物与TiO2超微粒在溶液中通过静电相互吸引,能够形成基态复合物。通过吸收光谱和荧光光谱,计算了磺化酞菁与TiO2在溶液中的表现缔合平衡常数K.与相应的烷氧基取代酞菁化合物作比较,并通过单光子技术测定染料荧光寿命。结合荧光光谱,证明了磺化酞菁与TiO2在溶液中的缔合作用,有利于激发态酞菁染料向半导体TiO2的导带注入电子,从而发生分子间的电子转移反应,将磺化酞菁吸附在TiO2纳晶薄膜电极上,进行光电性能测试。结果表明,染料敏化TiO2纳晶薄膜电极光电响应的大小与染料在电极表面吸附的强弱有关。 相似文献
158.
SENSITIVITY OF ACTIVATED MURINE PERITONEAL MACROPHAGES TO PHOTODYNAMIC KILLING WITH BENZOPORPHYRIN DERIVATIVE 总被引:2,自引:0,他引:2
David W. C. Hunt Hui-Jun Jiang Julia G. Levy Agnes H. Chan 《Photochemistry and photobiology》1995,61(4):417-421
Abstract— This study compared the ability of highly purified resting and activated DBA/2 mouse peritoneal macrophages to survive treatment with the photosensitizer benzoporphyrin derivative (BPD, verteporfin) and light. Culture of macrophages with recombinant murine interferon-γ (rIFN-γ, 100 U/mL) for 72 h imparted a phenotypic and functional activation by dramatically increasing cell surface expression of major histocompatibility complex Class II (Ia) molecules and the formation of nitric oxide. The rIFN-γ-activated macrophages were significantly (P < 0.05) more sensitive (lethal dose to cause a 50% reduction in cell survival, LD50= 14.4 ± 1.1 ng/mL) to photodynamic killing with BPD and light (10 J/cm2) than cells (LD50= 18.2 ± 2.0 ng/mL) cultured in medium alone. In contrast, macrophages treated with different concentrations of bacterial lipopolysaccharide (LPS) were as resistant or more resistant to photodynamic killing than cells cultured in medium alone. No cytotoxic effect of BPD was detected in cultures containing the drug but protected from light. Comparable amounts of BPD were taken up in vitro by unactivated and rIFN-γ-activated macrophages, as detected by flow cytometric analysis. However, cells cultured with LPS (10 μg/mL) took up more BPD than macrophages cultured in medium alone or with rIFN-γ. The DBA/2 P815 mastocytoma cells took up greater amounts of the drug and were subsequently more vulnerable to treatment with BPD and light (LD50= 6.9 ng/mL) than macrophages cultured under any condition. The explanation for the increased vulnerability of rIFN-γ-activated macrophages and the greater resistance of LPS-activated macrophages, relative to medium-cultured macrophages, to photodynamic killing with BPD is uncertain. However, the increased susceptibility of macrophages, activated with the immunomodulatory cytokine IFN-γ, to treatment with BPD and light might indicate how photodynamic therapy could interfere with the development of experimental autoimmune disease, conditions in which activated macrophages are known to be involved. 相似文献
159.
160.
Li-Wei Wang Hui-Jun Li Ping Li Ying-Jie Wei Dan Tang Ling Yi Zheng-Ming Qian 《Chromatographia》2007,66(5-6):395-399
The objective of this research was to establish a simple, practical and efficient method for routine quantitative analysis of Erigeron breviscapus and its extract injection to control their qualities. The reversed phase high performance liquid chromatographic method was adopted to determine simultaneously the contents of two major classes of constituents namely phenolic acids and flavonoids, which were usually ignored in previous studies of E. breviscapus. Under the optimum conditions, three flavonoids including scutellarin, scutellarein and apigenin and four phenolic acids including caffeic acid, chlorogenic acid, 3,4-O-dicaffeoylquinic acid and 3,5-O-dicaffeoylquinic acid were successfully separated on a Zorbax SB-C18 column (250 × 4.6 mm I.D., 5.0 μm particle size) at 25 °C. Of the three flavonoids, scutellatin is a flavone glucuronide. The mobile phase was a mixture of acetonitrile and 1.0% (v/v) aqueous acetic acid employing gradient elution at a flow rate of 1.0 mL min?1 and the detection wavelength was set at 330 nm. Regression equations revealed good linear relationship between the peak areas of the analytes and their concentrations (r 2 > 0.9990). The relative standard deviations of retention time and peak area were less than 0.33 and 1.45%. The intra- and inter-day precisions as determined from sample solutions were below 1.66 and 2.35%. And the recoveries ranged from 96.5 to 101.8%. The proposed method has been successfully applied to the simultaneous quantification of two major classes of constituents in E. breviscapus and its extract injection for the first time. 相似文献