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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1期68卷 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.

关键词： metabolon Diels-Alder reaction semipinacol rearrangement biosynthesis notoamides spiro polycyclic alkaloids

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Nanofiltration Membranes via Layer-by-layer Assembly and Cross-linking of Polyethyleneimine/Sodium Lignosulfonate for Heavy Metal Removal

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Chinese Journal of Polymer Science 2020年第9期38卷 965-972,I0006页

作者： Meng-yun Xie Jiang Wang Qing-yun wu Faculty of Materials Science and Chemical Engineering Ningbo UniversityNingbo 315211China School of Chemical Engineering and Technology Sun Yat-sen UniversityZhuhai 519082China

Layer-by-layer(LbL)assembly technology is a facile method for constructing thin film composite ***,a novel nanofiltration(NF)membrane was prepared by LbL assembly of polyethyleneimine(PEI)and sodium lignosulfonate(LS)followed by *** surface composition,morphology,and property of PEI/LS bilayer were detailedly investigated by FTIR/ATR,XPS,SEM,AFM,and water contact angle *** PEI/LS bilayer full of amino and hydroxyl groups presents increased roughness and improved ***,the NF performance of PEI/LS LbL assembly membranes can be modulated by bilayer number,polyelectrolyte concentration,and salt *** water flux reduced while the salt rejection greatly improved as increasing the bilayer numbers,PEI concentration,or NaCl *** than 95%MgSO4 and MgCl2,as well as 80%NaCl can be rejected by a NF membrane prepared by 6 PEI/LS bilayers,1 wt%PEI,0.5 wt%LS,and 1 mol/L ***,this NF membrane can be used to remove more than 95%heavy metal ions(Cd2+,Zn2+,Mn2+,Cr2+,Cu2+,and Ni2+).This work proposed a promising NF membrane by using PEI/LS as low cost polyelectrolytes and facile LbL assembly method,which should receive much attention in water purification.

关键词： Desalination Nanofiltration Sodium lignosulfonate Layer-by-layer Heavy metal

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Asymptotic analysis of outwardly propagating spherical flames

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Acta Mechanica Sinica 2012年第2期28卷 359-366页

作者： yun-Chao wu Zheng Chen State Key Laboratory for Turbulence and Complex SystemsDepartment of Mechanics and Aerospace Engineering Department of Aeronautics and AstronauticsCollege of EngineeringPeking University100871 BeijingChina

Asymptotic analysis is conducted for outwardly propagating spherical flames with large activation energy. The spherical flame structure consists of the preheat zone, reaction zone, and equilibrium zone. Analytical solutions are separately obtained in these three zones and then asymp- totically matched. In the asymptotic analysis, we derive a correlation describing the spherical flame temperature and propagation speed changing with the flame radius. This cor- relation is compared with previous results derived in the limit of infinite value of activation energy. Based on this correla- tion, the properties of spherical flame propagation are inves- tigated and the effects of Lewis number on spherical flame propagation speed and extinction stretch rate are assessed. Moreover, the accuracy and performance of different mod- els used in the spherical flame method are examined. It is found that in order to get accurate laminar flame speed and Markstein length, non-linear models should be used.

关键词： Propagating spherical flames Asymptotic anal- ysis Lewis number Stretch rate

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Enhancing oxygen reduction reaction of Pt-Co/C nanocatalysts via synergetic effect between Pt and Co prepared by one-pot synthesis

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Rare Metals 2023年第1期42卷 146-154页

作者： yun-Feng wu Ji-Wei Ma yun-Hui Huang School of Materials Science and Engineering Tongji UniversityShanghai201804China School of Materials Science and Engineering Huazhong University of Science and TechnologyWuhan430074China

Designing highly active and durable electrocatalysts towards oxygen reduction reaction(ORR)plays a paramount importance for proton exchange membrane fuel ***-based binary alloys Pt-M(M=3d-transition metals)possessing excellent electronic and geometric properties have received increasing interests as highly active ***,we report a series of Pt_(x)Co/C(x=1,2,3)catalysts by a facile one-pot soft-chemistry *** the acidic conditions,the mass activities of PtCo/C,Pt_(2)Co/C and Pt_(3)Co/C are 0.526,0.462 and 0.441 A·mgPt^(-1),which are 2.60,2.31 and 2.22 times higher than that of Pt/C(0.200 A·mgPt^(-1)),*** specific activities of PtCo/C,Pt_(2)Co/C and Pt_(3)Co/C are 706.59,679.41 and 801.83μA·cm^(-2),which are accordingly 2.89,2.76 and 3.28 times higher than that of Pt/C(244.75μA·cm^(-2)).Notably,Pt_(3)Co/C shows a remarkable *** 5000 cycles of the accelerated durability testing,the mass activity and specific activity of Pt_(3)Co/C catalyst are 2.47 and 3.80 times higher than that of the commercial Pt/C,*** improved ORR activity and durability can be ascribed to the synergistic interaction between Pt and Co.

关键词： Proton exchange membrane fuel cells(PEMFCs) Pt_(x)Co/C catalysts Synergetic effect Oxygen reduction reaction(ORR) One-pot synthesis

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Strong interactions of incident shock wave with boundary layer along compression corner

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Chinese Journal of Aeronautics 2020年第12期33卷 3149-3157页

作者： Shanguang GUO yun wu Hua LIANG Science and Technology on Plasma Dynamics Laboratory Air Force Engineering UniversityXi'an 710038China

The coherent structure and instability of the interaction of incident shock wave with boundary layer developing on a compression corner are experimentally *** experiments are carried out in a supersonic wind tunnel of Mach number *** attention is paid to shock patterns and unsteady shock motions induced by the separation *** high-speed schlieren is used to visualize the flowfield evolution and to characterize the *** snapshot proper orthogonal decomposition of schlieren sequences is applied to investigate the primary coherent structure in the *** Fourier transform and continuous wavelet transformation are applied to characterize the *** results show that there are large-scale low-frequency oscillations of the shock waves and small-scale high-frequency pulsations in the separation *** peak frequency of shock oscillation is mainly concentrated in the range of 100–1000 *** pulsation of the small flow structure in the separation bubble is mainly concentrated above 12.5 k *** on the results of experimental analysis,the preliminary mechanism of the largescale instability of such interaction is obtained.

关键词： Shock wave Boundary layer Interaction Flow mechanism Instability

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Modulating sparks in a pulse train for repetitive and energy efficient plasma generation

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High Voltage 2023年第6期8卷 1168-1179页

作者： Bo Yin Yifei Zhu yun wu Institute of Aero‐Engine School of Mechanical EngineeringXi'an Jiaotong UniversityXi'anChina School of Electrical Engineering Xi'an Jiaotong UniversityXi'anChina Science and Technology of Plasma Dynamics Laboratory Airforce Engineering UniversityXi'anChina

Spark is a widely studied plasma source for active species production;however,it ex-periences unstable transitions(*** a thermal arc)at high frequencies or long pulse *** this study,the sparks generated in a pulse train were studied and modulated based on a physics‐corrected deep learning *** results show that a highly repeatable and stable spark plasma source can be achieved by automatically adjusting the voltage amplitude according to the discharge frequency in a high‐frequency pulse train within the time scale of the fluid *** influences of the electron number density increasing mode and modulated driven voltage profiles on the energy efficiencies were also studied.

关键词： Spark pulse energy

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Effect of dihedral angle of bridge unit on the performance of dye-sensitized solar cell

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Chinese Chemical Letters 2016年第6期27卷 927-932页

作者： yun wu Xin Li School of Chemical and Environmental Engineering Shanghai Institute of Technology Shanghai 201418 China Division of Theoretical Chemistry and Biology School of Biotechnology KTH Royal Institute of Technology SE-10691 Stockholm Sweden Key Laboratory of Synthetic Chemistry of Natural Substances Shanghai Institute of Organic Chemistry Chinese Academy of Sciences Shanghai 200032 China

In this work, we investigated the impact of bridge unit on their photo-physical and photovoltaic performance. Increased planarity of the dyes effectively extended the absorption, but reduces the efficiency. Interestingly we found that dyes with a thiophene conjugate unit showed inferior performance when compared with benzene. Theoretical computation indicates a large dihedral angle in the latter system. EIS analysis evidenced the severe recombination in the thiophene-based dye,showing that good planarity may lead to dye aggregation and decrease the efficiency.

关键词： Planarity Recombination Dihedral angle Dye-loading Solar cell

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A Tensor Neural Network with Layerwise Pretraining： Towards Effective Answer Retrieval

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Journal of Computer Science & Technology 2016年第6期31卷 1151-1160页

作者： Xin-Qi Bao yun-Fang wu Key Laboratory of Computational Linguistics Peking University Beijing 100871 China

In this paper we address the answer retrieval problem in community-based question answering. To fully capture the interactions between question-answer pairs, we propose an original tensor neural network to model the relevance between them. The question and candidate answers are separately embedded into different latent semantic spaces, and a 3-way tensor is then utilized to model the interactions between latent semantics. To initialize the network layers properly, we propose a novel algorithm called denoising tensor autoencoder （DTAE）, and then implement a layerwise pretraining strategy using denoising autoencoders （DAE） on word embedding layers and DTAE on the tensor layer. The experimental results show that our tensor neural network outperforms various baselines with other competitive neural network methods, and our pretraining DTAE strategy improves the system＇s performance and robustness.

关键词： artificial intelligence language parsing and understanding machine learning

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AN ASYMPTOTIC SOLUTION OF VELOCITY FIELD IN SHIP WAVES

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Journal of Hydrodynamics 2006年第4期18卷 387-392页

作者： wu yun-gang TAO Ming-de Department of Mechanics and Engineering Science and The Key Laboratory of Wave Scattering and RemoteSensing Information Fudan University Shanghai 200433 China

The stationary phase method in conventional Lighthill＇s two-stage scheme to get the expressions of the velocity field was given up in this paper. The method that Ursell had used in deducing the elevation expression of ship wave was adopted, and an asymptotic solution of velocity field of ship waves on an inviscid fluid that is perfectly fit for the region inside and outside the critical lines was obtained. It is very convenient to be used in SAR technique.

关键词： ship waves velocity field remote sensing,asymptotic solution

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Operations Research in the Blockchain Technology

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Journal of the Operations Research Society of China 2022年第2期10卷 401-422页

作者： Xu Wang Ling-yun wu IAM MADISNCMISAcademy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049China Department of Industrial Engineering Tsinghua UniversityBeijing 100084China

In the past decade,as a decentralized distributed database technology blockchain has developed rapidly at an unprecedented speed and been applied to a wide range of scenarios far beyond cryptocurrencies,for example,insurance,energy,risk management,and Internet of things(IoT).The blockchain technology combines the achievements from cryptography,computer science,economics,and operations research and has increasingly attracted attention from both academia and *** the operations research has been widely adopted in the blockchain technology,there is a lack of comprehensive survey on the operations research in blockchain-related *** order to fill the gap,we analyze the blockchain technology through the perspective of operations research and present a comprehensive review of the operations research problems from the aspects of security and stability,efficiency and performance,and resource *** paper aimed to help the relevant readers in the field of operations research find their own points of interest and conduct in-depth research on the blockchain technology,hoping to promote the rapid development and wider application of the blockchain technology in the near future.

关键词： Blockchain Operations research Security Efficiency Resource allocation

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