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951.
In this technical note, the Hopf bifurcation in a new Lorenz-type system is studied. By analyzing the characteristic equations, the existence of a Hopf bifurcation is established. Some corresponding dynamics are also discussed briefly. Numerical simulations are carried out to illustrate the main theoretical results. 相似文献
952.
Xinming Zhou Yantao He Miao Wang Yixiang Ding 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3):651-659
o- and p-Trifluoromethylphenyl phosphates designed as mechanism-based phosphotyrosine phosphatase inactivators have been prepared. Some of them show herbicidal activities. 相似文献
953.
Markov Chain Monte Carlo (MCMC) Method for Studying Magnetic Behaviors in Trinuclear Cobalt(II) Compound 下载免费PDF全文
Dr. Quan Wang Hang‐Xing Li Dr. Kun‐Miao Wang Dr. Xiao Wang Zhe Xue Lei Jia Dr. Lin Du Prof. Qi‐Hua Zhao 《化学:亚洲杂志》2018,13(11):1415-1418
A CoII coordination polymer built from a mixed azide and zwitterionic pyridinium ions and its temperature‐dependent magnetic properties are described. We used the Markov chain Monte Carlo (MCMC) method to fit the data, and found the following results: (1) there are strong correlations between the model parameters; (2) the data at above 28 K are well fitted by the magnetism model. 相似文献
954.
955.
Li‐Ping Lu Si‐Si Feng Hong‐Mei Zhang Miao‐Li Zhu 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(6):m283-m284
The crystal structure of the title compound, [Cu2(C12H7N2O)2]·H2O, shows that this dinuclear complex has shorter Cu—N, Cu—O and Cu—Cu distances within the coordination sphere than similar reported complexes. The complex molecule is located on a centre of symmetry and the water molecule is on a twofold axis of the space group C2/c. The discrete complex molecules are extended into a two‐dimensional supramolecular array viaπ–π stacking interactions, intermolecular Cu⋯Cu interactions and C—H⋯O hydrogen bonds. 相似文献
956.
Na Li Junbiao Chang Lingheng Kong Shuangjing Wang Dandan Wang Miao Cheng Xingwei Li 《催化学报》2018,39(12):1881-1889
A straightforward and efficient protocol for dearomatizing indoles is described. The reaction, catalyzed by an inexpensive Co(III)/Zn(II) catalyst, starts from easily accessible N-pyrimidinyl indoles and ene-yne ketones. Mild reaction conditions, high diastereoselectivity, a broad substrate scope, effective functional group tolerance, and reasonable to remarkable yields were observed. 相似文献
957.
958.
Hui Qin Yuanyuan Miao Ke Zhang Jian Xu Haopeng Sun Wenyuan Liu Feng Feng Wei Qu 《Tetrahedron》2018,74(47):6809-6814
A practical convenient conversion of oxindoles into the corresponding spirocyclopropyl oxindoles is achieved efficiently using bromoethylsulfonium salt, which is easily prepared on a large scale and is stable crystalline. This reaction of bromoethylsulfonium salt with different substituted unprotected oxindoles proceeded under mild condition and provided moderate yields. 相似文献
959.
Twelve 5, 10, 15, 20‐tetra[(4‐alkoxy‐3‐ethyloxy)phenyl]porphyrin hydroxylanthanide complexes Ln[(C n OEOP)4P](OH) (n?=?12, 14, 16;Ln?=?Tb, Dy, Er, Yb) and three ligands have been synthesized and their composition, structure and spectral properties studied. Their liquid crystalline behaviour is also presented. Differential scanning calorimetry and polarizing optical microscopy reveal that all exhibit a discotic liquid crystalline phase. X‐ray diffraction shows that the mesophase is a hexagonal columnar, Colh. The lanthanide ion, which is coordinated to the four nitrogen atoms of the porphyrin and to the oxygen atom of the hydroxyl group, is out of the porphyrin molecular plane. All the complexes are stable below 200°C and undergo complete decomposition at 800°C. The fluorescence quantum yields of the lanthanide complexes are much lower than those of the corresponding ligands. The electrochemical studies show that the redox potentials do not change on varying the chain length. 相似文献