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91.
《Analytical letters》2012,45(6):589-602
Abstract A method is described for assessing radiochemical purity of compounds measured by radioimmunoassay. This method is applicable in cases when chromatography is used prior to the radioimmunoassay proper. In individual fractions of the chromatographic zone containing the compound assayed, both radioactivity (e. g. in DPM) and mass (e. g. in pg) are measured. The measurement of mass is performed using radioimmunoassay. Radiochemical purity is assumed, if the radioactivity/mass ratio (specific activity) in individual fractions of the zone is constant. The constancy of specific activity is tested statistically using a regression analysis. A radioimmunoassay of progesterone in a blood plasma pool collected during the follicular phase of the menstrual cycle was used to demonstrate the practical features of the assessment of radiochemical purity. Radiochemical pure progesterone could be obtained only after repeated chromatography. Purification to radiochemical purity resulted in a significantly decreased estimate of progesterone contents in the plasma pool investigated. A value of 344 pg/ml was obtained, in contrast to the value of 422 pg/ml found prior to the repeated chromatography. The former value can be considered an accurate and valid estimate. 相似文献
92.
Mikheil Doroshenko Maria Gonzales Andreas Best Hans‐Jürgen Butt Kaloian Koynov George Floudas 《Macromolecular rapid communications》2012,33(18):1568-1573
The phase separation of the polymer blend polystyrene/poly(methyl phenyl siloxane) (PS/PMPS) is studied in situ by laser scanning confocal microscopy (LSCM) and by fluorescence correlation spectroscopy (FCS) at macroscopic and microscopic length scales, respectively. It is shown for the first time that FCS when combined with LSCM can provide independent information on the local concentration within the phase‐separated domains as well as the interfacial width. 相似文献
93.
《Analytical letters》2012,45(20):1725-1733
Abstract A new simple and fast micro method has been established to determine the optical purity of a small amount of amino acids (0.1–1 μg/ml). The amino acids react readily with fluorescamine to form pyrrolinone-type chromophores, which show strong CD bands at 400–300 nm and much larger optical rotation than the free amino acids in the visible spectral range. 相似文献
94.
JI Ying-Hua 《理论物理通讯》2008,50(4):897-902
Taking into account the interaction between electrons and phonons, in the case without-rotating-wave approximation, we study the entangling
property between the mesoscopic circuit and environment at coherent state or
equilibrium state. The result indicates that, in long time limit t→∞, the averages of charge and current in the circuit only depend on the average of the system at the initial state when the environment is initially at thermal equilibrium. However, when the environment is initially
at coherent state, the average of charge and current in the circuit is
determined by the specific coherent state ensemble. Generally speaking, the
entanglement between the circuit and environment will lead to the quantum
state purity declining of the circuit, then the circuit emerges decoherent
phenomenon, and so a mixed state appears. Purity changes are related to the initial quantum state of environment and circuit. With the further evolution of time, coherence will be gradually restored, but cannot return to 1. 相似文献
95.
96.
In this paper, we consider the entanglement dynamics of a four-qubit model [2006 Phys. Rev. A 74 042328] where two entangled qubits a and b locally interact with separate qubits A and B via the spin-exchange-like Hamiltonian. We study the effect of purity of initial entangled state of qubits a, b on the entanglement evolution and its relation with energy transfer. Also, we find that the total bipartite entanglement of qubits a, b plus A, B is not a constant any longer when the initial entangled state of a, b is not pure, which is a complement to the result in the paper [2007 J. Phys. B 40 S45] for the pure case. 相似文献
97.
98.
首先测量了高纯n型硅样品在接近液氦温度区域内随温度变化的光热电离光谱,确定了硅样品的最佳光热电离温度范围. 在该温度范围内,在有本征带隙光照射条件下,测量了样品的高分辨率光热电离光谱,同时观察到了来自主要浅杂质施主磷以及补偿性杂质硼的正信号. 随后,应用外加磁场,对硼的光热电离光谱进行了研究,发现来自硼的光热电离信号,在外加磁场作用下,发生了由正向负信号的转变. 通过对该现象进行分析讨论,排除了该现象是温度效应的可能,指出普遍用来解释补偿性杂质光热电离响应的Darken模型存在不足,而少数载流子快速复合模 相似文献
99.
100.