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The maximal Lyapunov exponent of a co-dimension two-bifurcation system excited by a bounded noise

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Acta Mechanica Sinica 2012年第2期28卷 511-519页

作者： sheng-hong li Xian-Bin liu State Key Lab of Mechanics and Control for Mechanical Structures College of Aerospace EngineeringNanjing University of Aeronautics and Astronautics210014 NanjingChina School of Mathematics and Physics Jiangsu University of Science and Technology212003 ZhenjiangChina

In the present paper, the maximal Lyapunov ex- ponent is investigated for a co-dimension two bifurcation system that is on a three-dimensional central manifold and subjected to parametric excitation by a bounded noise. By using a perturbation method, the expressions of the invari- ant measure of a one-dimensional phase diffusion process are obtained for three cases, in which different forms of the matrix B, that is included in the noise excitation term, are assumed and then, as a result, all the three kinds of singular boundaries for one-dimensional phase diffusion process are analyzed. Via Monte-Carlo simulation, we find that the an- alytical expressions of the invariant measures meet well the numerical ones. And furthermore, the P-bifurcation behav- iors are investigated for the one-dimensional phase diffusion process. Finally, for the three cases of singular botmdaries for one-dimensional phase diffusion process, analytical ex- pressions of the maximal Lyapunov exponent are presented for the stochastic bifurcation system.

关键词： Maximal Lyapunov exponent Perturbationmethod. Bounded noise. Diffusion process

Potassium iodide catalyzed reductive dehalogenation ofα-halo-ketones using Hantzsch ester diethyl 1,4-dihydro-2,6-dimethylpyridine-3,5-dicarboxylate as reductant

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Chinese Chemical Letters 2010年第8期21卷 931-934页

作者： hong sheng li Yi Qun li Department of Chemistry Jinan UniversityGuangzhou 510632China

In the presence of diethyl 1,4-dihydro-2,6-dimethylpyridine-3,5-dicarboxylate（DHP） and a catalytic amount of potassium iodide,severalα-halo ketones were easily reduced to the corresponding ketones in acetone *** procedure presented here showed several merits such as short reaction time,practical experimental and isolated procedure,and excellent yields of products.

关键词： Dehalogenation α-Halo ketones Hantzsch ester 1 4-Dihydro-2 6-dimethylpyridine-3 5-dicarboxylate Potassium iodide

Peltate glandular trichomes of Colquhounia seguinii harbor new defensive clerodane diterpenoids

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Journal of Integrative Plant Biology 2014年第9期56卷 928-940页

作者： Chun-Huan li Yan liu Juan Hua Shi-hong Luo sheng-hong li State Key Laboratory of Phytochemistry and Plant Resources in West China Kunming Institute of Botanythe Chinese Academy of Sciences University of Chinese Academy of Sciences

Glandular trichomes produce a wide variety of secondary metabolites that are considered as major defensive chemicals against herbivore *** morphology and secondary metabolites of the peltate glandular trichomes of a lianoid Labiatae,Colquhounia seguinii Vaniot,were *** new clerodane diterpenoids,seguiniilactones A-C（1-3）,were identified through precise trichome collection with laser microdissection,metabolic analysis with ultra performance liquid chromatography-tandem mass spectrometer,target compound isolation with classical phytochemical techniques,structure elucidation with spectroscopic *** compounds showed significant antifeedant activity against a generalist plant-feeding insect Spodoptera *** A（1） was approximately 17-fold more potent than the commercial neem oil.a-Substituted α,β-unsaturated γ-lactone functionality was found to be crucial for strong antifeedant activity of this class of *** results indicated that the levels of these compounds in the peltate glandular trichomes and leaves were sufficiently high to deter the feeding by generalist *** antifungal activity was observed for seguiniilactone C（3） against six predominant fungal species isolated from the diseased leaves of C seguinii,while seguiniilactones A and B were generally *** findings suggested that seguiniilactones A-C might be specialized secondary metabolites in peltate glandular trichomes for the plant defense against insect herbivores and pathogens.

关键词： Colquhounia seguinii Vaniot peltate glandular trichomes laser microdissection clerodane diterpenoids antifeedant and antifungal activities

Four New Taxoids from the Barks of Taxus yunnanensis

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Chinese Chemical Letters 2001年第1期12卷 63-66页

作者： sheng hong li hong Jie ZHANG Ping YAO Han Dong SUN Phytochemistry Laboratory Kunming Institute of BotanyAcademia SinicaKunming 650204 Guizhou Institute of Traditional Chinese Medicine Guiyang 550002

From the barks of Taxus yunnanensis, a new paclitaxel-related compound, 7-xylosyl-taxol D (1), and three new 11(15-->1)-abeotaxoids, taxuyunnanines P-R (2-4) have been isolated. Their structures were determined on the basis of spectral methods. Taxuyunnanines P-R are a rare type of naturally occurring abeotaxoids with an opened D-ring system.

关键词： 11(15→1)-abeotaxoids 7-xylosyl-taxol D Barks Taxus yunnanensis Taxuyunnanines P-R

A New Abietane Diterpenoid from the Barks of Taxus yunnanensis

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Chinese Chemical Letters 2001年第5期12卷 429-430页

The structure of a new abietane diterpenoid, taxayunnin (1), from the barks of Taxus yunnanensis, was determined by spectroscopic analysis. A known abietane diterpenoid, taxamairin C (2), was also isolated.

关键词： Taxus yunnanensis Taxaceae abietane diterpenoid Taxayunnin.

Global Periodic Attractor for Strongly Damped and Driven Wave Equations

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Acta Mathematicae Applicatae Sinica 2006年第1期22卷 75-80页

作者： hong-yan li sheng-fan Zhou Department of Mathematics Shanghai University Shanghai 200444 China

In this paper we consider the strongly damped and driven nonlinear wave equations under homogeneous Dirichlet boundary conditions. By introducing a new norm which is equivalent to the usual norm, we obtain the existence of a global periodic attractor attracting any bounded set exponentially in the phase space, which implies that the system behaves exactly as a one dimensional system.

关键词： Wave equation global periodic attractor equivalent norm

Novel triphenylamine-based two-photon absorption dyes including benzophenone parts

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Chinese Chemical Letters 2009年第11期20卷 1279-1282页

作者： Fang Gao Nv Dan Hu hong Ru li sheng Tao Zhang College of Chemistry and Chemical Engineering Chongqing University Chongqing 400044 China

New two-photon absorption dyes including benzophenone parts, p-N,N-diphenylamino-p＇-phenacylstilbene （C1）, 4,4-di-（4- benzoylstyrene）yltriphenylamine （C2） and 4,4＇,4＇-tri（4-benzoylstyrene）yltriphenylamine （C3）, were synthesized and characterized by ^1H NMR and elemental analysis. The ratio of the molar extinction coefficients of compounds was approximately equal to the ratio of the branch amount of the compounds, namely, C1：C2：C3 was 1：2：3. Extremely high fluorescence quantum yields were detected for these compounds. These molecules exhibited obvious two-photon upconcerted fluorescence as excited by 800 nm Ti：sapphire femtosecond laser.

关键词： Synthesis Spectroscopy Two-photon absorption Benzophenone

Time delay and cross-correlated Gaussian noises-induced stochastic stability and regime shift between steady states for an insect outbreak system

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International Journal of Biomathematics 2019年第4期12卷 301-323页

作者： Kang-Kang Wang Ya-Jun Wang Hui Ye sheng-hong li School of Science Jiangsu University of Science and Technology Zhenjiang 212003 P. R. China Center of Complex Systems and Network Science Research Southeast University Nanjing 210096 P. R. China School of Mathematical Sciences Nanjing Normal University Nanjing 210097 P. R. China

In this paper, we focus on investigating the stochastic stability and the regime transition between the endangered state and the boom state for a time-delayed insect growth system driven by correlated external and internal noises. By use of the Fokker Planck equation, the method of small time delay approximation and the fast descent method, we explore in detail the joint action of noise terms and time delay on the mean reproduction and depression time for the insect population. Our investigations indicate that the pseudo-resonance phenomenon of the mean first-passage time (MFPT) occurs because of the impact of different noises and time delay. Through the numerical calculation, it is discovered that multiplicative noise can speed up the shift of the insect population from the boom state to the endangered one, while the noise correlation and time delay can propel the insect system to evolve from the endangered state to the boom state and improve the biological stability. In addition, the impact of the additive noise on the stability of the biological system depends on the positive and negative situation of the noise correlation. On the other hand, during the process of suppressing the insect explosion, it is beneficial to the pest control to amplify the association noise strength and weaken the intensities of the multiplicative, additive noises and time delay. However, during the process of eliminating the pests, it can produce nice effect on the disinsection to increase time delay, the intensities of multiplicative and additive noises and weaken the strength of noise correlation.

关键词： Insect outbreak model correlated noises time delay mean reproduction time mean depression time

A New Indole Alkaloid from limonia Crenulata

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Chinese Chemical Letters 2001年第3期12卷 243-244页

作者： Xue Mei NIU sheng hong li li Yan PENG Gao Xiong RAO Han Dong SUN Laboratory of Phytochmistry Kunming Institute of BotanyAcademia SinicaKunming 650204 Yunnan College of Traditional Chinese Medicine Kunming 650011

A new indole alkaloid, crenulatine 1, was isolated from the stems of limonia Crenulata. The structure was identified by spectral means.

关键词： limonia Crenulata Rutaceae alkaloids indole alkaloid crenulatine