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科技纵览 2018年第5期 40-45页

作者： Olgica Milenkovic Ryan Gabrys han mao kiah S.M.Hossein Tabatabaei Yazdi

5000年前，一名男子在阿尔卑斯山死去。他的死因可能是头部受到重击，也可能是肩部中箭后流血不止。尽管研究者们已经研究了奥茨（以他被发现的地点阿尔卑斯山奥茨塔尔而命名）近30年，但他身上仍隐藏着大量未知等待我们发现。

关键词：字节数阿尔卑斯山试管隐藏

High Fe‑Loading Single‑Atom Catalyst Boosts ROS Production by Density Effect for Efficient Antibacterial Therapy

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Nano-Micro Letters 2025年第2期17卷 187-203页

作者： Si Chen Fang Huang Lijie mao Zhimin Zhang han Lin Qixin Yan Xiangyu Lu Jianlin Shi Department of Cardiology Shanghai Tenth People’s HospitalSchool of MedicineTongji UniversityShanghai 200092People’s Republic of China Shanghai Institute of Ceramics Chinese Academy of SciencesShanghai 200050People’s Republic of China Shanghai Frontiers Science Center of Nanocatalytic Medicine School of MedicineTongji UniversityShanghai 200092People’s Republic of China

The current single-atom catalysts(SACs)for medicine still suffer from the limited active site ***,we develop a synthetic method capable of increasing both the metal loading and mass-specific activity of SACs by exchanging zinc with *** constructed iron SACs(h^(3)-FNC)with a high metal loading of 6.27 wt%and an optimized adjacent Fe distance of~4 A exhibit excellent oxidase-like catalytic performance without significant activity decay after being stored for six months and promising antibacterial ***,a“density effect”has been found at a high-enough metal doping amount,at which individual active sites become close enough to interact with each other and alter the electronic structure,resulting in significantly boosted intrinsic activity of single-atomic iron sites in h^(3)-FNCs by 2.3 times compared to low-and medium-loading ***,the overall catalytic activity of h^(3)-FNC is highly improved,with mass activity and metal mass-specific activity that are,respectively,66 and 315 times higher than those of commercial Pt/*** addition,h^(3)-FNCs demonstrate efficiently enhanced capability in catalyzing oxygen reduction into superoxide anion(O_(2)·^(−))and glutathione(GSH)*** in vitro and in vivo assays demonstrate the superior antibacterial efficacy of h^(3)-FNCs in promoting wound *** work presents an intriguing activity-enhancement effect in catalysts and exhibits impressive therapeutic efficacy in combating bacterial infections.

关键词： Nanocatalytic medicine Single-atom catalysts Reactive oxygen species(ROS) High metal loading Oxidase catalysis

Deciphering fungal metabolon coupling tandem inverse-electrondemand Diels-Alder reaction and semipinacol rearrangement for the biosynthesis of spiro polycyclic alkaloids

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Science China Chemistry 2025年第01期 288-296页

作者： Shuai Liu Wen-Qiang Xu Ying-Tong Di Man-Cheng Tang Ding-Kang Chen Ming-Ming Cao Yao-Wen Chang Hong-Yu Tang Chun-mao Yuan Jun-Bo Yang Zhi-Li Zuo han Guo Zi-Fei Xu Ying Zeng Yun-Dong Wu Xiao-Jiang Hao Key Laboratory of Phytochemistry and Natural Medicines (Chinese Academy of Sciences) Kunming Institute of Botany Chinese Academy of Sciences University of Chinese Academy of Sciences Lab of Computational Chemistry and Drug Design State Key Laboratory of Chemical Oncogenomics Peking University Shenzhen Graduate School Shenzhen Bay Laboratory State Key Laboratory of Microbial Metabolism School of Life Sciences & Biotechnology Shanghai Jiao Tong University State Key Laboratory of Functions and Applications of Medicinal Plants Guizhou Medical University Molecular Biology Experimental Center Germplasm Bank of Wild Species in Southwest China Kunming Institute of Botany Chinese Academy of Sciences Yunnan Key Laboratory for Wild Plant Resources Kunming Institute of Botany Chinese Academy of Sciences Research Unit of Chemical Biology of Natural Anti-Virus Products Chinese Academy of Medical Sciences

In the intricate process of natural product biosynthesis, a metabolon can enhance metabolic flux by associating sequential enzymes. A fungal metabolon, comprising of flavin-dependent monooxygenase Spe F and P450 monooxygenase Spe G, is identified in the biosynthesis of spiro polycyclic alkaloids(+)-notoamide B and its diastereomer(+)-versicolamide B. Using notoamide E as a substance, Spe F/Spe G metabolon can control the stereoselectivity of its 2,3-epoxidation, followed by hydrogen atom ion at C-17 to generate reactive epoxide tau-m A with dienyl iminium unit. Subsequently,(+)-notoamide B and(+)-versicolamide B are produced via tandem nonenzymatic inverse-electron-demand Diels-Alder reaction and semipinacol rearrangement. This provides the first example of metabolon in the biosynthesis of spiro-prenylated indole alkaloids.

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ON SOME PROPERTIES OF LIENARD SYSTEMS

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Applied Mathematics and Mechanics(English Edition) 2002年第4期23卷 454-462页

作者： han mao-an(韩茂安) Department of Mathematics Shanghai Jiaotong University Shanghai 200030 P R China

Some sharp sufficient conditions for generalized Lienard systems to have positive or negative semi-orbits which do not cross the vertical isocline are given. Applications of the main results to some polynomial systems... 详细信息

关键词： Lienard system local property global property

Existence and bifurcation of integral manifolds with applications

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Science China Mathematics 2005年第7期48卷 940-957页

作者： han mao'an CHEN Xianfeng Department of Mathematics Shanghai Normal University Shanghai 200234 China Department of Mathematics Shanghai Jiao Tong University Shanghai 200030 China

In this paper a bifurcation theorem on the existence of integral manifolds is obtained by using contracting principle. As an application, sufficient conditions for a higher dimensional system to have an integral manifold are given. Especially the existence and uniqueness of a 3-dimensional invariant torus appearing in a 4-dimensional autonomous system with singularity of codimension two are proved.

关键词： existence, bifurcation, invariant manifold, invariant torus.

On Stability Discrimination of Limit Cycles for Piecewise Smooth Systems

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Acta Mathematica Sinica,English Series 2024年第7期40卷 1785-1803页

作者： mao An han Xia Yu ZHOU School of Mathematical Sciences Zhejiang Normal UniversityJinhua321004P.R.China

This paper is concerned with the problem of stability discrimination of limit cycles for piecewise smooth *** first establish the Poincaré map near a periodic orbit,and deduce the first order derivative of the map for general piecewise smooth systems on the ***,we obtain a sufficient condition for determining the stability of limit cycles for these systems.

关键词： Piecewise smooth system limit cycle stability

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On the Number of Limit Cycles of a Z_4-equivariant Quintic Near-Hamiltonian System

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Acta Mathematica Sinica,English Series 2015年第11期31卷 1805-1824页

作者： Xian Bo SUN mao An han Department of Applied Mathematics Guangxi University of Finance and Economics The Institute of Mathematics Shanghai Normal University

In this paper, we study the number of limit cycles of a near-Hamiltonian system having Za- equivariant quintic perturbations. Using the methods of Hopf and heteroclinic bifurcation theory, we find that the perturbed system can have 28 limit cycles, and its location is also given. The main result can be used to improve the lower bound of the maximal number of limit cycles for some polynomial systems in a previous work, which is the main motivation of the present paper.

关键词： Limit cycle near-Hamiltonian system heteroclinic loop Za-equivariance Hopf bifurca-tion

On the Bifurcations of a Hamiltonian Having Three Homoclinic Loops under Z_3 Invariant Quintic Perturbations

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Acta Mathematica Sinica,English Series 2007年第5期23卷 869-878页

作者： Yu Hal WU mao An han Department of Mathematics Jiang Su University Zhenjiang 212013 P. R. China Department of Mathematics Shanghai Normal University Shanghai 200234 P. R. China

A cubic system having three homoclinic loops perturbed by Z3 invariant quintic polynomials is considered. By applying the qualitative method of differential equations and the numeric computing method, the Hopf bifurcation, homoclinic loop bifurcation and heteroclinic loop bifurcation of the above perturbed system are studied. It is found that the above system has at least 12 limit cycles and the distributions of limit cycles are also given.

关键词： homoclinic loop bifurcation heteroclinic loop bifurcation Hopf bifurcation stability limit cycles

Complex Symmetric C0-semigroups on A^2(C+)

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Acta Mathematica Sinica,English Series 2020年第10期36卷 1171-1182页

作者： Kai Kai han mao Fa WANG School of Mathematics and Statistics Hebei University of Economics and BusinessShijiazhuang 050061P.R.China School of Mathematics and Statistics Wuhan UniversityWuhan 430072P.R.China

In this paper,we study complex symmetric C0-semigroups on the Bergman space A^2(C+) of the right half-plane C+.In contrast to the classical case,we prove that the only involutive composition operator on A^2(C+) is the identity operator,and the class of J-symmetric composition operators does not coincide with the class of normal composition *** addition,we divide semigroups{φt}of linear fractional self-maps of C+into two *** show that the associated composition operator semigroup{Tt}is strongly continuous and identify its infinitesimal *** an application,we characterize Jσ-symmetric C0-semigroups of composition operators on A^2(C+).

关键词： C0-semigroup Bergman space composition operator complex symmetry

Flower-like Au/Ag/TiO2 nanocomposites with enhanced photocatalytic efficiency under visible light irradiation

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Science China Chemistry 2017年第4期60卷 521-527页

作者： Fei han Xin mao Qing-Hua Xu Department of Chemistry National University of Singapore Singapore 117543 Singapore National University of Singapore Nanoscience & Nanotechnology Initiative (NUSNNl)-Nanocore Singapore 117576 Singapore National University of Singapore (Suzhou) Research Institute Suzhou 215123 China

Uniform flower-like TiO2 coated Au nanostars and core-shell Au@Ag nanostars with different amounts of Ag coating were prepared through a facile method by hydrolysis of TiF4 under an acidic environment. The photocatalytic capability of these flower-like nanocomposites under visible light irradiation was found to be enhanced by up to 4.7-fold compared to commercial P25 TiO2 nanoparticles. The enhanced photocatalytic activity was ascribed to improved light absorption and hot electron inj ection from the photo-excited Au@Ag core to the TiO2 shell.

关键词： metal nanoparticles TiO2 plasmon resonance nano-flower photocatalysis