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21.
22.
研究分数扩散模型的参数估计及其应用问题.分数扩散模型是一类由分数Brownian运动驱动的随机微分方程.主要结果有:(1)利用二次变差方法给出模型中扩散系数的估计量,通过最小二乘法给出模型中漂移系数的估计量;(2)证明这些估计量的一致收敛性和渐近正态性;(3)利用MCMC方法对此估计量进行验证,并通过R软件将上述模型以及参数估计量应用到SHIBOR利率中进行实证研究. 相似文献
23.
Lluvia Itzel López-López Sendar Daniel Nery-Flores Aidé Sáenz-Galindo Denisse de Loera 《合成通讯》2017,47(23):2247-2253
Mannich bases are formed in a noncatalytic multicomponent reaction, which is promoted by ultrasound irradiation. The procedure avoids the use of toxic solvents, catalyst, and purification, generating the desired compounds in excellent yields and short reaction times. 相似文献
24.
Emira Kahrović Adnan Zahirović Sandra Kraljević Pavelić Emir Turkušić Anja Harej 《Journal of Coordination Chemistry》2017,70(10):1683-1697
The binuclear Ru(II) complexes with Schiff bases derived from 5-chlorosalicyladehyde and 2-aminopyridine and its 5-substituted salicylideneimine homologues were tested in vitro against cervical carcinoma (HeLa), metastatic colorectal adenocarcinoma (SW620), lung adenocarcinoma (A549), breast adenocarcinoma (MCF-7), and human lung fibroblast (WI-38) cell lines. All compounds showed strong antiproliferative activity with extremely low IC50 values. The compounds expressed strong activity against gram-positive bacteria, Staphylococcus aureus and Enterococcus faecalis. 相似文献
25.
Muhammad Shabbir Paul R. Raithby Lynne H. Thomas Hammad Ismail Faiza Arshad 《Journal of Coordination Chemistry》2017,70(14):2463-2478
Four novel ON donor Schiff bases (E)-3-((4-phenoxyphenylimino)methyl)benzene-1,2-diol (HL1),(E)-3-((4-(4-biphenyloxy)phenyliminomethyl)benzene-1,2-diol (HL2), (E)-3-((4-naphthoxyphenylimino)methyl)benzene-1,2-diol (HL3), (E)-3-((4-(2-naphthoxy)phenylimino)methyl)benzene-1,2-diol (HL4) and their copper(II) complexes bis((E)-3-((4-phenoxyphenylimino)methyl)benzene-1,2-diol) copper(II) (Cu(L1)2) bis((E)-3-((4-(4-biphenyloxy)phenylimino)methyl)benzene-1,2-diol) copper(II) (Cu(L2)2), bis((E)-3-((4-naphthoxyphenylimino)methyl)benzene-1,2-diol) copper(II) (Cu(L3)2), bis((E)-3-((4-(2-naphthoxy)phenylimino)methyl)benzene-1,2-diol) copper(II) (Cu(L4)2) have been synthesized and characterized by spectroscopic (FTIR, NMR, UV–visible) and elemental analysis. The crystal structures of HL1, HL2, HL3, and HL4 have been determined, which reveal intramolecular N-H?O (HL1, HL2, HL3, and HL4) hydrogen bonds in the solid state. Keto-amine and enol-imine tautomerism is exhibited by the Schiff bases in solid and solution states. The Schiff bases and their copper(II) complexes have been screened for their biological activities. In antimicrobial assays (antibacterial and antifungal), HL4 showed promising results against all strains through dual inhibition property while the rest of the compounds showed activity against selective strains. On the other hand, in cytotoxic, DPPH, and inhibition of hydroxyl (OH) free radical-induced DNA damage assays, the results were found significantly correlated with each other, i.e. the ligands HL1 and HL2 showed moderate activity while their complexes Cu(L1)2 and Cu(L2)2 exhibited prominent increase in activity. As the results of these assays are supporting each other, it represents the strong positive correlation and antioxidant nature of investigated compounds. 相似文献
26.
In this paper, the normal form analysis of quadratic-cubic Swift-Hohenberg equation with a dissipative term is investigated by using the multiple-scale method. In addition, we obtain Hamiltonian-Hopf bifurcations of two equilibria and homoclinic snaking bifurcations of one-peak and two-peak homoclinic solutions by numerical simulations. 相似文献
27.
Yang Qi 《数学研究通讯:英文版》2017,33(1)
In this article, we use Zalcman Lemma to investigate the normal family of meromorphic functions concerning shared values, which improves some earlier related results. 相似文献
28.
In this paper, we discuss an inverse problem, i.e., the reconstruction of a linear differential dynamic system from the given discrete data of the solution. We propose a model and a corresponding algorithm to recover the coefficient matrix of the differential system based on the normal vectors from the given discrete points, in order to avoid the problem of parameterization in curve fitting and approximation. We also give some theoretical analysis on our algorithm. When the data points are taken from the solution curve and the set composed of these data points is not degenerate, the coefficient matrix $A$ reconstructed by our algorithm is unique from the given discrete and noisefree data. We discuss the error bounds for the approximate coefficient matrix and the solution which are reconstructed by our algorithm. Numerical examples demonstrate the effectiveness of the algorithm. 相似文献
29.
Jairo Z. Goncalves 《代数通讯》2017,45(12):5193-5201
Let k(t) be the field of rational functions over the field k, let σ be a k-automorphism of K = k(t), let D = K(X;σ) be the ring of fractions of the skew polynomial ring K[X;σ], and let D? be the multiplicative group of D. We show that if N is a noncentral normal subgroup of D?, then N contains a free subgroup. We also prove that when k is algebraically closed and σ has infinite order, there exists a specialization from D to a quaternion algebra. This allows us to explicitly present free subgroups in D?. 相似文献
30.
Stability,periodicity, and symmetries of certain second‐order fractional difference equation with quadratic terms via KAM theory 下载免费PDF全文
Mirela Garić‐Demirović M. Nurkanović Z. Nurkanović 《Mathematical Methods in the Applied Sciences》2017,40(1):306-318
By using the Kolmogorov–Arnold–Moser theory, we investigate the stability of the equilibrium solution of the difference equation where A ,B ,D > 0,u ?1,u 0>0. We also use the symmetries to find effectively the periodic solutions with feasible periods. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献