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91.
A. Manjon J. A. Ferragut J. C. Garcia-Borron J. L. Iborra 《Applied biochemistry and biotechnology》1984,9(2):173-185
Fluorescence spectra and soluble quenching of intrinsic protein fluorescence were used as indexes of conformational changes
suffered by frog epidermis tyrosinase. The activation process and the immobilization of the enzyme involving either free amino
groups or its carbohydrate moiety were studied. The conformational changes resulting from denaturation of each one of the
protein derivatives, as well as the effect of active center copper extraction, were followed by fluorescence studies.
The results showed that: (a) both activation and immobilization were accompanied by conformational changes of the protein
leading to more unfolded states; (b) neither enzyme nor immobilized enzyme were fully unfolded upon denaturation although
enzymic activity was lost; (c) the enzyme immobilized through its carbohydrate moiety was more unfolded upon denaturation
than the enzyme immobilized through amino groups, thus pointing to a higher conformational stabilization in the last situation;
and (d), that tryptophyl residues moved to a localization near the active site upon activation. 相似文献
92.
通用模拟退火用于稳健多元分析校正 总被引:4,自引:0,他引:4
模拟退火是一种全局优化算法,具有跨越局部最优点的机制,最小一乘是一种较常用的最小二乘更为稳健的优化准则,更适用于可能偏离正态分布的实际数据集,本文探讨了用最小一乘为准则并利用模拟退火方法同时测定多组分体系的可能性。应用于2-3组分药物体系分析,获得了满意的结果,本文还探讨了改变步长提高模拟退火算法优化精度的方法。 相似文献
93.
94.
The calculation of Net Asset Values and Solvency Capital Requirements in a Solvency 2 context–and the derivation of sensitivity analyses with respect to the main financial and actuarial risk drivers–is a complex procedure at the level of a real company, where it is illusory to be able to rely on closed-form formulas. The most general approach to performing these computations is that of nested simulations. However, this method is also hardly realistic because of its huge computation resources demand. The least-squares Monte Carlo method has recently been suggested as a way to overcome these difficulties. The present paper confirms that using this method is indeed relevant for Solvency 2 computations at the level of a company. 相似文献
95.
《印度化学会志》2021,98(9):100122
Salophen is a weakly fluorescent Schiff base which forms emissive co-ordination complexes with Zn2+ and Al3+. The complex with Al3+ is significantly more fluorescent than that with Zn2+, presumably because the dimeric complex with Zn2+ is associated with additional nonradiative channels. This contention has been put to test, through a careful investigation of excited state dynamics of the anionic form of salophen (Sal2−), which is the form in which the ligand exists in the complexes. The emissive excited state of the anion (Sal2−) has been found to be solvated and conformationally relaxed, over tens of picosecond. It is significantly more fluorescent than the neutral compound, with fluorescence lifetime that is longer by almost two orders of magnitude. Fluorescence lifetime of the anion is in fact longer than that of the complex with Zn2+ and slightly less than that of the complex with Al3+. So, the earlier hypothesis about additional nonradiative deactivation pathways in the Zn2+ complex gains credence from the present study. 相似文献
96.
Defect turbulence described by the one-dimensional complex Ginzburg–Landau equation is investigated and analyzed via a birth–death process of the local structures composed of defects, holes, and modulated amplitude waves (MAWs). All the number statistics of each local structure, in its stationary state, are subjected to Poisson statistics. In addition, the probability density functions of interarrival times of defects, lifetimes of holes, and MAWs show the existence of long-memory and some characteristic time scales caused by zigzag motions of oscillating traveling holes. The corresponding stochastic process for these observations is fully described by a non-Markovian master equation. 相似文献
97.
98.
Umair Ahmed Charles Turquand d’Auzay Masaya Muto Nilanjan Chakraborty Ryoichi Kurose 《Proceedings of the Combustion Institute》2019,37(3):2821-2830
The statistical behaviour of the variances, covariance and gradients of the reaction progress variable (c), and the mixture fraction (ξ) have been analysed in a pulverised coal jet flame using a three-dimensional carrier phase direct numerical simulation (DNS) dataset. It has been observed that the Favre-probability density functions (PDFs) of c and ξ can be parametrised by the standard β function. Furthermore, the log-normal distribution has been found to accurately represent |?c| and |?ξ|. It is also found that ?c and ?ξ remain aligned throughout the flame brush. Finally the joint PDF of |?c| and |?ξ| has been compared with the product of the PDF of |?c| and PDF of |?ξ| extracted from carrier phase DNS, and it has been found that |?c| and |?ξ| are not statistically independent in the case investigated.The bivariate log-normal distributions with and without correlation have also been considered, and the former is found to be in better agreement with the carrier phase DNS data. 相似文献
99.
《Physics letters. A》2014,378(5-6):494-496
In this paper we study the time series of sunspots by using two different approaches, analyzing its self-affine behavior and studying its distribution. The long-range correlation exponent α has been calculated via Detrended Fluctuation Analysis and the power law vanishes to values greater than 11 years. On the other hand, the distribution of the sunspots obeys a q-exponential decay that suggests a non-extensive behavior. This observed characteristic seems to take an alternative interpretation of the sunspots dynamics. The present findings suggest us to propose a dynamic model of sunspots formation based on a nonlinear Fokker–Planck equation. Therefore its dynamic process follows the generalized thermostatistical formalism. 相似文献
100.
Víctor Leiva 《商业与工业应用随机模型》2019,35(1):133-137
Sam C. Saunders, the son of Elizabeth Cundiff and Winston E. Saunders, was born in Richland, OR, on February 24, 1931. The family moved to La Grande, OR, in 1944, where Sam completed high school and two years at Eastern Oregon College. He then received the BSc degree in Mathematics from the University of Oregon, Eugene, OR, in 1952, and he attended the University of Washington, Seattle, WA, receiving a PhD degree under Z. W. Birnbaum. After graduating, he accepted employment at the Boeing Company in its Mathematical Services Unit and, in 1972, a position as a Full Professor at Washington State University, Pullman, WA, from which he retired in 1996. 相似文献