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Supported Recyclable Metal-free Frustrated Lewis Pair Catalyst for Catalytic Hydrogenation of Substituted Pyridines to Piperidines

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Chemical Research in Chinese Universities 2024年第4期40卷 682-689页

作者： MA Shaohua tang zhiyong CAS Key Laboratory for Nanosystem and Hierarchical Fabrication CAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing100190P.R.China University of Chinese Academy of Sciences Beijing100049P.R.China

The construction of heterogeneous frustrated Lewis pairs(FLPs)catalysts is crucial for realizing highly efficient and recyclable pyridines catalytic *** this work,we prepared a recyclable heterogenous FLPs catalyst CMP-BF with conjugated microporous polymer CMP-ethynyl as the support via self-catalyzed 1,1-carboboration reaction with commercial Lewis acid B(C_(6)F_(5))_(3).The as-synthesized CMP-BF demonstrates superior heterogenous catalytic hydrogenation performance(conversion>99%),and considerable stability(84%conversion after three cycles)in recyclable hydrogenation of 2,*** work provides insights into the fabrication and catalytic application of recyclable heterogenous FLP catalysts.

关键词： Pyridine hydrogenation Frustrated Lewis pair Conjugated microporous polymer

Structure-Preserving Recurrent Neural Networks for a Class of Birkhoffian Systems

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Journal of Systems Science & Complexity 2024年第2期37卷 441-462页

作者： XIAO Shanshan CHEN Mengyi zHANG Ruili tang Yifa LSEC ICMSECAcademy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049China School of Mathematics and Statistics Beijing Jiaotong UniversityBeijing 100044China

In this paper,the authors propose a neural network architecture designed specifically for a class of Birkhoffian systems—The Newtonian *** proposed model utilizes recurrent neural networks(RNNs)and is based on a mathematical framework that ensures the preservation of the Birkhoffian *** authors demonstrate the effectiveness of the proposed model on a variety of problems for which preserving the Birkhoffian structure is important,including the linear damped oscillator,the Van der Pol equation,and a high-dimensional *** with the unstructured baseline models,the Newtonian neural network(NNN)is more data efficient,and exhibits superior generalization ability.

关键词： Birkhoffian system k(z,t)-symplectic neural networks recurrent neural network

Identifying and localizing of seismogenic electromagnetic anomalies from data observed by permanent MT stations

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Science China Earth Sciences 2024年第5期67卷 1698-1713页

作者： Bing HAN Wenbao HU Guoze zHAO Ji tang State Key Laboratory of Earthquake Dynamics Institute of GeologyBeijing 100029China Key Laboratory of Exploration Technologies for Oil and Gas Resources of Ministry of Education Yangtze UniversityWuhan 430100China

In this research, an arbitrarily oriented electric dipole at subsurface is used to simulate Seismogenic Electromagnetic(SEM) radiation emanating from a seismic zone during its gestation phase. Analytical synthesis of responses at the Lijiang magnetotelluric(MT) station has revealed that SEM radiation could induce identifiable anomalies in the electromagnetic(EM)spectrum, apparent resistivity and phase within specific frequency bands. Background variations were extracted from long-term observation data of Dali and Lijiang MT stations, enabling the identification of SEM anomalies related to the Yunlong and Yangbi earthquakes. Multiple parameters of dipole sources at subsurface were obtained by applying the Differential Ant Colony Optimization(DACO) algorithm to anomalous data of two stations with multi-frequencies and various response functions. The spatial distribution of these predicted dipoles is predominantly clustered in or around the seismogenic area, with their azimuthal orientation aligning towards the seismogenic fault in general. This study has demonstrated the potential of using subsurface electric dipole simulations for SEM radiation analysis, offering a feasible approach for the prediction and understanding of seismogenic zones.

关键词： MT responses Identifying SEM anomaly Vector electric dipole responses Localizing SEM sources by inversion

Recent advances in g-C_(3)N_(4)-based direct z-scheme photocatalysts for environmental and energy applications

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Chinese Journal of Structural Chemistry 2024年第2期43卷 66-84页

作者： Xiaoming Fu Haibo Huang Guogang tang Jingmin zhang Junyue Sheng Hua tang School of Intelligent Engineering and Technology Jiangsu Vocational College of Finance&EconomicsHuai'anJiangsu223003PR China School of Modem Equipment Manufacturing Changzhou Institute of Light Industry Technology ChangzhouJiangsu213164PR China School of Environmental Science and Engineering Qingdao UniversityQingdao266071PR China School of Materials Science and Engineering Hainan UniversityHaikou570228PR China

In the midst of the rapid advancement of photocatalysis,direct z-scheme heterojunction photocatalysts have emerged as a powerful solution to address environmental challenges and the looming energy *** precise engineering of direct z-scheme heterojunction photocatalysts proves highly beneficial in optimizing their elec-tronic structure,ultimately enhancing their photocatalytic ***,graphitic carbon nitride(g-C_(3)N_(4))has recently gained recognition as a leading candidate for the creation of direct z-scheme heterojunctions,owing to its favorable attributes such as a moderate band-gap(2.7 eV),high reduction potential and abundant active *** this review,we offer a concise overview of the fundamental principles and recent advancements in g-C_(3)N_(4)-based direct z-scheme photocatalytic ***,we delve into the various practical applica-tions of g-C_(3)N_(4)-based direct z-scheme photocatalysts,specifically in the realms of energy conversion and envi-ronmental *** applications include the removal of contaminant pollutants through photocatalytic degradation,water splitting(comprising H_(2)-generation,O_(2)-evolution,and overall water splitting),and CO_(2)***,we present comprehensive characterization methods and strategies aimed at further enhancing the photocatalytic activity of g-C_(3)N_(4)-based direct z-scheme photocatalytic *** conclude,this review offers summarizing insights and a brief discussion on future challenges and prospects pertaining to g-C_(3)N_(4)-based direct z-scheme *** believe that this review will inspire continued exploration and foster a deeper understanding of the groundbreaking possibilities within photocatalytic *** also provides valuable guidance for the design and construction of innovative direct z-scheme photocatalysts.

关键词： Carbon nitride Photocatalyst z-scheme systems Environmental remediation Energy conversion

Solvent effects on Diels-Alder reaction in ionic liquids:A reaction density functional study

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Chinese Journal of Chemical Engineering 2024年第2期66卷 180-188页

作者： zijiang Dou Weiqiang tang Peng Xie Shuangliang zhao Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology and School of Chemistry and Chemical Engineering Guangxi UniversityNanning 530004China State Key Laboratory of Chemical Engineering and School of Chemical Engineering East China University of Science and TechnologyShanghai 200237China

Extensive experimental studies have been performed on the Diels-Alder(DA)reactions in ionic liquids(ILs),which demonstrate that the IL environment can significantly influence the reaction rates and ***,the underlying microscopic mechanism remains *** this work,the multiscale reaction density functional theory is applied to explore the effect of 1-butyl-3-methylimidazolium hexafluorophosphate([BMIM][PF_(6)])solvent on the reaction of cyclopentadiene(CP)with acrolein,methyl acrylate,or *** analyzing the free energy landscape during the reaction,it is found that the polarization effect has a relatively small influence,while the solvation effect makes both the activation free energy and reaction free energy *** addition,the rearrangement of local solvent structure shows that the cation spatial distribution responds more evidently to the reaction than the anion,and this indicates that the cation plays a dominant role in the solvation effect and so as to affect the reaction rates and selectivity of the DA reactions.

关键词： Solvent effect Ionic liquids Diels-Alder reaction Reaction density functional theory

Recent Advances in Mechanistic Understanding of Metal-Free Carbon Thermocatalysis and Electrocatalysis with Model Molecules

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Nano-Micro Letters 2024年第7期16卷 74-97页

作者： Wei Guo Linhui Yu Ling tang Yan Wan Yangming Lin CAS Key Laboratory of Design and Assembly of Functional Nanostructures Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002People’s Republic of China Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials Xiamen Institute of Rare Earth MaterialsHaixi InstituteChinese Academy of SciencesXiamen 361021People’s Republic of China State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002People’s Republic of China Institute of Urban Environment Chinese Academy of SciencesXiamen 361021People’s Republic of China

Metal-free carbon,as the most representative heterogeneous metal-free catalysts,have received considerable interests in electro-and thermo-catalytic reac-tions due to their impressive performance and *** the past decade,well-designed carbon catalysts with tunable structures and heteroatom groups coupled with various characterization techniques have proposed numerous reaction ***,active sites,key intermediate species,precise structure-activity relationships and dynamic evolution processes of carbon catalysts are still rife with controversies due to the monotony and limitation of used experimental *** this Review,we sum-marize the extensive efforts on model catalysts since the 2000s,particularly in the past decade,to overcome the influences of material and structure limitations in metal-free carbon *** both nanomolecule model and bulk model,the real contribution of each alien species,defect and edge configuration to a series of fundamentally important reactions,such as thermocatalytic reactions,electrocatalytic reactions,were systematically *** with in situ techniques,isotope labeling and size control,the detailed reaction mechanisms,the precise 2D structure-activity relationships and the rate-determining steps were revealed at a molecular ***,the outlook of model carbon catalysis has also been proposed in this work.

关键词： Metal-free carbon catalysts Model catalyst Electrocatalysis Active site Reaction mechanisms

Bimetal MOF-derived NiFe-P nanocomposites coupled with Cu_(3)P nanoparticles to construct tandem electron transfer channels for photocatalytic hydrogen evolution

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Journal of Environmental Sciences 2024年第3期137卷 333-346页

作者： Haiyan zhang Shitao Yang Peng zhu Senpei tang Ming Li College of Chemistry and Chemical Engineering Jishou UniversityJishou 416000China School of Account Hunan University of Technology and BusinessChangsha 410205China

Finely modulated light-induced charge separation and transfer is a central challenge to achieve efficient *** progress has been made in this field,most of the previous research works focused on the separation or migration of photogenerated carriers but did not build a bridge between the *** to realize the strong driving and precise migration of carriers has become the focus of our *** report an ingeniously designed ternary *** NiFe-MOF as the“parent material”,the FeP_(4)/Ni_(x)P_(y)heterojunction is derived in situ while maintaining the frame structure through gas-solid reaction,and finally the z-type electron transfer is *** Cu_(3)P anchoring spindle matrix,an electron transport tunnel is opened up in Cu_(3)P/FeP_(4)/Ni_(x)P_(y)ternary heterojunction under the action of p-n heterojunction built-in electric field driving and accurate energy band *** strong driving force of the built-in electric field provides an inexhaustible power for the transmission of electrons,and the fine series of electron transmission channels realizes the precise transmission of *** above fine design makes the perfect fit between the built-in electric field and the electron transfer channel,which not only effectively improves the embarrassing situation of insufficient electron driving force of hydrogen evolution reaction in the previous research,but also makes up for the weakening of semi-conductor reduction ability caused by the construction of traditional p-n *** research work provides a new idea for the construction of multiple heterostructures and the design of fine interface engineering in the future.

关键词： Cu_(3)P/FeP_(4)/Ni_(x)P Built-in electric field Electron transfer channels Photocatalysis

Joint position optimization,user association,and resource allocation for load balancing in UAV-assisted wireless networks

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Digital Communications and Networks 2024年第1期10卷 25-37页

作者： Daosen zhai Huan Li Xiao tang Ruonan zhang Haotong Cao School of Electronics and Information Northwestern Polytechnical UniversityXian710072China State Key Laboratory of Integrated Services Networks Xidian UniversityXian710071China Department of Computing Hong Kong Polytechnic UniversityHong Kong SARChina

Unbalanced traffic distribution in cellular networks results in congestion and degrades spectrum *** tackle this problem,we propose an Unmanned Aerial Vehicle(UAV)-assisted wireless network in which the UAV acts as an aerial relay to divert some traffic from the overloaded cell to its adjacent underloaded *** fully exploit its potential,we jointly optimize the UAV position,user association,spectrum allocation,and power allocation to maximize the sum-log-rate of all users in two adjacent *** tackle the complicated joint optimization problem,we first design a genetic-based algorithm to optimize the UAV ***,we simplify the problem by theoretical analysis and devise a low-complexity algorithm according to the branch-and-bound method,so as to obtain the optimal user association and spectrum allocation *** further propose an iterative power allocation algorithm based on the sequential convex approximation *** simulation results indicate that the proposed UAV-assisted wireless network is superior to the terrestrial network in both utility and throughput,and the proposed algorithms can substantially improve the network performance in comparison with the other schemes.

关键词： Load balance Unmanned aerial vehicle Userassociation Resource management

70 Gbps PAM-4850-nm oxide-confined VCSEL without equalization and pre-emphasis

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Journal of Semiconductors 2024年第5期45卷 5-7页

作者： Anjin Liu Bao tang zhiyong Li Wanhua zheng Key Laboratory of Optoelectronic Materials and Devices Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Accelink technologies co. LtdWuhan 430205China Key Laboratory of Solid-State Optoelectronics Information Technology Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China

Directly modulated 850-nm vertical-cavity surface-emitting lasers(VCSELs)with the advantages of low cost,high modulation speed,good reliability,and low power consumption,are the key sources in the optical interconnects with multimode fibers for the supercomputers,data centers,and machine learning applications[1−3].Typically,non-return-tozero(NRz)modulation format is used.

关键词： return confined fibers