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901.
在pH 2.2 BR缓冲介质中, 磷钨杂多酸(PTA)与格拉司琼(GSN)相互作用形成离子缔合物, 不仅引起吸收光谱的变化, 还导致共振散射光谱(RLS)的显著增强并产生新的RLS光谱, 最大RLS峰位于333 nm附近, 其RLS增强程度与格拉司琼浓度成线性关系, 检出限和线性范围分别为12 ng/mL和0.04~3.0 μg/mL。文中研究了反应产物的吸收和RLS光谱特征, 优化反应条件的影响, 据此发展了以磷钨杂多酸为光谱探针的灵敏、简便、快速测定格拉司琼的新方法。将方法用于血清中格拉司琼含量的快速定, 结果满意。讨论了离子缔合反应和RLS增强机理。 相似文献
902.
ZnS微粒子的光学截面及红外发射率光谱的计算 总被引:13,自引:1,他引:12
应用微粒子Mie散射理论,计算了ZnS粒子的散射、吸收和消化截面,并计算了相应粒子的红外发射率光谱,讨论了ZnS粒子在4.0-10.0μm红外波段上的振荡吸收现象。 相似文献
903.
We report dynamic light scattering and small angle neutron scattering studies of the pressure-induced structural transition
of nonionic micelles of surfactant polyoxyethylene 10 lauryl ether (C12E10) in the pressure range 0 to 2000 bar. Measurements
have been performed on 1 wt% C12E10 in aqueous solution with and without the addition of KF. Micelles undergo sphere to lamellar
structural transitions as the pressure is increased. On addition of KF, rod-like micelles exist at ambient pressure, which
results in rod-like to lamellar structural transition at a much lower pressure in the presence of KF. Micellar structural
transitions have been observed to be reversible.
相似文献
904.
905.
拉曼光谱在癌症诊断中的应用 总被引:4,自引:0,他引:4
在各种疾病中癌症的死亡率居第二位。另一方面只要能早期发现和诊断,几乎所有癌症都能治疗。本文介绍拉曼光谱在癌症诊断和抗癌药物筛选中的应用,结果表明拉曼光谱可能识别恶性变化的标记物,在癌症的早期诊断中是一项有用的技术。 相似文献
906.
I. Bartoš 《Surface science》2009,603(2):369-1009
Photoemission multiple scattering theory is used to describe the electron transport in the surface region of a crystal. Intensities of photoemission from core levels of atoms situated in subsurface atomic layers are calculated as a function of the emitter distance from the surface. The electron angle resolved attenuation length (ARAL) is extracted from the exponential fitting of the intensity decays of photoemission into different directions. Substantial anisotropy of the electron ARAL is found for the Cu(1 1 1) surface in Mg Kα photoexcitation of Cu 2p3/2 levels and correlated with the orientation of highly packed atomic rows. Enhanced photoemission contributions from specific subsurface layers, caused by electron forward focusing effects, are reported. 相似文献
907.
We have simulated the scattering in a pulsed atomic beam evaporated from a superfluid 4He film. Assuming that the atoms leaving the surface of the film have an equilibrium Maxwellian distribution, we find that the experimentally observed deviations from Lambert's law are explained by scattering of the atoms after evaporation. 相似文献
908.
909.
C. Vanneste 《The European Physical Journal B - Condensed Matter and Complex Systems》2001,23(3):391-404
This paper presents an extension to electromagnetic fields of the wave automaton, which was introduced in recent years for
describing wave propagation in inhomogeneous media. Using elementary processes obeying a discrete Huygens' principle and satisfying
fundamental symmetries such as time reversal and reciprocity, this new wave automaton is capable of modeling Maxwell's equations
in 3+1 dimensions. It supplements the methods that were developed early for scalar and spinor fields.
Received 19 July 2001 相似文献
910.
K. Araki T. Yoshikawa I. Ishii T. Goto H. Tanida B. Lüthi 《Physica B: Condensed Matter》2009,404(19):3187-3190
We performed ultrasonic measurements on a single crystal of PrMg3. The characteristic Curie-type softening was observed in temperature dependence of transverse mode (C11-C12)/2 below 8 K down to 0.8 K. This softening in PrMg3 is caused by a non-Kramers Γ3 doublet ground state having electric quadrupoles Ou and Ov and magnetic octupole Txyz. The elastic constant (C11-C12)/2 shows a minimum at 25 K, which cannot be explained by the quadrupole susceptibility based on the crystal electric field (CEF) levels. However, considering higher order (l=4) multipole, namely electric hexadecapole, the minimum around 25 K was well reproduced. At lower temperatures, a shoulder anomaly in elastic constant being deviated from the Curie-type softening was observed around 100-800 mK in (C11-C12)/2. This anomaly is unaffected by magnetic fields up to 14 T. 相似文献