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Recent progress in photocatalytic NAD(P)H regeneration for photocatalytic-enzymatic-coupling system

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Frontiers of Chemical Science and Engineering 2024年第4期18卷 1-24页

作者： Wei Lan Maodi Wang Huicong Dai qihua Yang Key Laboratory of the Ministry of Education for Advanced Catalysis Materials Zhejiang Key Laboratory for Reactive Chemistry on Solid SurfacesInstitute of Physical ChemistryZhejiang Normal UniversityJinhua 321004China

The enzymatic redox reactions in natural photosynthesis rely much on the participation of cofactors,with reduced nicotinamide adenine dinucleotide/nicotinamide adenine dinucleotide phosphate(NADH/NADPH)or their oxidized form(NAD+/NADP+)as an important redox power.The photocatalytic regeneration of expensive and unstable NADH/NADPH in vitro is an important process in enzymatic reduction and has attracted much research attention.Though different types of photocatalysts have been developed for photocatalytic NADH/NADPH regeneration,the efficiency is still relatively low.To elucidate the key factors affecting the performance of photocatalytic NADH/NADPH regeneration is helpful to rationally design the photocatalyst and improve the photocatalytic efficiency.In this paper,we overview the recent progress in photocatalytic NADH/NADPH regeneration with the focus on the strategies to improve the visible light adsorption,the charge separation and migration efficiency,as well as the surface reaction,which jointly determine the overall photocatalytic regeneration efficiency.The potential development of photocatalytic NADH/NADPH regeneration and photocatalyticenzymatic-coupling system is prospected finally.

关键词： photocatalytic-enzymatic coupling NAD(P)H regeneration photocatalysis efficiency

Synthesis of covalent organic framework materials and their application in the field of sensing

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Nano Research 2024年第1期17卷 162-195页

作者： Weiyu Zhang Shiwei Liu qihua Sun Ning Tian Zhaofeng Wu Xinjiang Key Laboratory of Solid-State Physics and Devices Urumqi 830046China School of Physics Science and Technology Xinjiang UniversityUrumqi 830046China

Covalent organic frameworks(COFs)are an emerging type of porous crystalline polymers formed by combining strong covalent bonds with organic building blocks.Due to their large surface area,high intrinsic pore space,good crystallization properties,high stability,and designability of the resultant units,COFs are widely studied and used in the fields of gas adsorption,drug transport,energy storage,photoelectric catalysis,electrochemistry,and sensors.In recent years,the rapid development of the Internet of Things and people’s yearning for a better life have put forward higher and more requirements for sensors,which are the core components of the Internet of Things.Therefore,this paper reviews the recent progress of COFs in synthesis methods and sensing applications,especially in the last five years.This paper first introduces structure,properties,and synthesis methods of COFs and discusses advantages and disadvantages of different synthesis methods.Then,the research progress of COFs in different sensing fields,such as metal ion sensors,gas sensors,biomedical sensors,humidity sensors,and pH sensors,is introduced systematically.Conclusions and prospects are also presented in order to provide a reference for researchers concerned with COFs and sensors.

关键词： covalent organic framework materials structural design and synthesis sensing application gas sensors

Theoretical study on magnetocaloric effect and its electric-field regulation in CrI_(3)/metal heterostructure

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Science China(Physics,Mechanics & Astronomy) 2024年第2期67卷 134-141页

作者： Weiwei He Ziming Tang qihua Gong Min Yi Wanlin Guo State Key Laboratory of Mechanics and Control for Aerospace Structures Key Laboratory for Intelligent Nano Materials and Devices of Ministry of EducationInstitute for Frontier ScienceNanjing University of Aeronautics and AstronauticsNanjing 210016China MIIT Key Laboratory of Aerospace Information Materials and Physics College of PhysicsNanjing University of Aeronautics and AstronauticsNanjing 211106China

The extraordinary properties of a heterostructure by stacking atom-thick van der Waals(vdW)magnets have been extensively studied.However,the magnetocaloric effect(MCE)of heterostructures that are based on monolayer magnets remains to be explored.Herein,we deliberate MCE of vd W heterostructure composed of a monolayer CrI_(3)and metal atomic layers(Ag,Hf,Au,and Pb).It is revealed that heterostructure engineering by introducing metal substrate can improve MCE of CrI_(3),particularly boosting relative cooling power to 471.72μJ m^(-2)and adiabatic temperature change to 2.1 K at 5 T for CrI_(3)/Hf.This improved MCE is ascribed to the enhancement of magnetic moment and intralayer exchange coupling in CrI_(3)due to the CrI_(3)/metal heterointerface induced charge transfer.Electric field is further found to tune MCE of CrI_(3)in heterostructures and could shift the peak temperature by around 10 K in CrI_(3)/Hf,thus manipulating the working temperature window of MCE.These theoretical results could enrich the research on low-dimensional magnetocaloric materials.

关键词： magnetocaloric effect heterostructure metal substrate

Molecular design of recyclable thermosetting polyimide and its composite with excellent mechanical and tribological properties

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Friction 2024年第3期12卷 452-461页

作者： Xiaoyue WANG Zenghui YANG Tingmei WANG qihua WANG Xinrui ZHANG Song LI Key Laboratory of Science and Technology on Wear and Protection of Materials Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China

Recyclability of thermosetting polymers and their composites is a challenge for alleviating environmental pollution and resource waste.In this study,solvent-recyclable thermosetting polyimide(PI)and its composite were successfully synthesized.The tensile strength,elongation at break,and young’s modulus of PI are 108.70±7.29 MPa,19.35%±3.89%,and 2336.42±128.00 MPa,respectively.The addition of reduced graphene oxide(RGO)not only enhances the mechanical properties of PI but also endows it with excellent tribological properties.The PI illustrates a high recycling efficiency of 94.15%,but the recycled composite exhibits inferior mechanical properties.The recycling and utilization of PI and its composite are realized through imine bonds(-C=N),which provides new guidance for solving the problem of environmental pollution and resource waste and is potential application in the field of sustainable tribology.

关键词： thermosetting polyimide(PI) recyclability dynamic covalent bonds friction and wear polymer composites

Linear group delay spectral interferometry for full-range precision absolute length metrology

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Photonics Research 2024年第2期12卷 313-320页

作者： JINDONG WANG JINGSHENG HUANG qihua LIU WEI DU FUMIN ZHANG TAO ZHU Key Laboratory of Optoelectronic Technology&Systems(Ministry of Education) Chongqing UniversityChongqing 400044China State Key Laboratory of Precision Measuring Technology&Instruments Tianjin UniversityTianjin 300072China

The optical frequency comb serves as a powerful tool for distance measurement by integrating numerous stable optical modes into interferometric measurements,enabling unprecedented absolute measurement precision.Nonetheless,due to the periodicity of its pulse train,the comb suffers from measurement dead zones and ambiguities,thereby impeding its practical applications.Here,we present a linear group delay spectral interferometer for achieving precise full-range distance measurements.By employing a carefully designed linear group delay(LGD)device for phase modulation of the comb modes,interference can occur and be easily measured at any position.Our approach effectively eliminates the dead zones and ambiguities in comb-based ranging,without the need for cumbersome auxiliary scanning reference devices or reliance on complex high-repetition-rate combs or high-resolution spectrometers.We conducted length metrology experiments using a mode-locked comb referenced to a rubidium clock,achieving a large nonambiguity range up to 0.3 m,covering the entire measurement period.The maximum deviation compared to a laser interferometer was less than 1.5μm,and the minimum Allan deviation during long-term measurements reached 5.47 nm at a 500 s averaging time.The approach ensures high accuracy while maintaining a simple structure,without relying on complex external devices,thereby propelling the practical implementation of comb-based length metrology.

关键词： interferometer metrology delay

Tribological properties of PTFE-based fabric composites at cryogenic temperature

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Friction 2024年第2期12卷 245-257页

作者： Mingkun XU Zidan WANG Lihe GUO Liming TAO Tianbao MA Tingmei WANG qihua WANG Key Laboratory of Science and Technology on Wear and Protection of Materials Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China State Key Laboratory of Tribology Tsinghua UniversityBeijing 100084China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

Fabric composites are widely employed in self-lubricating bearing liners as solid lubrication materials.Although the tribological behaviors of fabric composites have been extensively studied,the cryogenic tribological properties and mechanisms have been scarcely reported and are largely unclear to instruct material design for aerospace and other high-tech applications.Herein,the tribological properties of polytetrafluoroethylene(PTFE)-based hybrid-fabric composites were investigated at cryogenic and ambient temperatures in the form of pin-on-disk friction under heavy loads.The results suggest that the friction coefficients of the hybrid-fabric composites obviously increase with a decrease in wear when the temperature drops from 25 to−150°C.Moreover,thermoplastic polyetherimide(PEI),as an adhesive for fabric composites,has better cryogenic lubrication performance than thermosetting phenol formaldehyde(PF)resin,which can be attributed to the flexible chemical structure of PEI.The excellent lubrication performance of hybrid-fabric composites is attributed to the transfer film formed by PTFE fibers on the surface of fabrics.

关键词： cryogenic temperatures fabric composites friction and wear transfer film

Westerlies Affecting the Seasonal Variation of Water Vapor Transport over the Tibetan Plateau Induced by Tropical Cyclones in the Bay of Bengal

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Advances in Atmospheric Sciences 2024年第5期41卷 881-893页

作者： Xiaoli ZHOU Wen ZHOU Dongxiao WANG Qiang XIE Lei YANG qihua PENG Key Laboratory of Polar Atmosphere-ocean-ice System for Weather and Climate Ministry of Education&Department of Atmospheric and Oceanic Sciences&Institute of Atmospheric SciencesFudan UniversityShanghai 200438China School of Marine Sciences Sun Yat-Sen UniversityZhuhai 519082China Institute of Deep-sea Science and Engineering Chinese Academic SciencesSanya 572000China State Key Laboratory of Tropical Oceanography South China Sea Institute of OceanologyChinese Academic ScienceGuangzhou 510301China Scripps Institution of Oceanography University of CaliforniaSan DiegoLa JollaCalifornia 92093USA

This study investigates the activity of tropical cyclones(TCs)in the Bay of Bengal(BOB)from 1979 to 2018 to discover the mechanism affecting the contribution rate to the meridional moisture budget anomaly(MMBA)over the southern boundary of the Tibetan Plateau(SBTP).May and October–December are the bimodal phases of BOB TC frequency,which decreases month by month from October to December and is relatively low in May.However,the contribution rate to the MMBA is the highest in May.The seasonal variation in the meridional position of the westerlies is the key factor affecting the contribution rate.The relatively southern(northern)position of the westerlies in November and December(May)results in a lower(higher)contribution rate to the MMBA.This mechanism is confirmed by the momentum equation.When water vapor enters the westerlies near the trough line,the resultant meridional acceleration is directed north.It follows that the farther north the trough is,and the farther north the water vapor can be transported.When water vapor enters the westerlies from the area near the ridge line,for Type-T(Type-R)TCs,water vapor enters the westerlies downstream of the trough(ridge).Consequently,the direction of the resultant meridional acceleration is directed south and the resultant zonal acceleration is directed east(west),which is not conducive to the northward transport of water vapor.This is especially the case if the trough or ridge is relatively south,as the water vapor may not cross the SBTP.

关键词： tropical cyclone Tibetan Plateau Bay of Bengal moisture budget weste

class activation maps;laser-induced damage;semantic segmentation;weakly supervised learning

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High Power Laser Science and Engineering 2024年第1期12卷 30-41页

作者： Yueyue Han Yingyan Huang Hangcheng Dong Fengdong Chen Fa Zeng Zhitao Peng qihua Zhu Guodong Liu School of Instrumentation Science and Engineering Harbin Institute of TechnologyHarbinChina Research Center of Laser Fusion China Academy of Engineering PhysicsMianyangChina

Segmenting dark-field images of laser-induced damage on large-aperture optics in high-power laser facilities is challenged by complicated damage morphology, uneven illumination and stray light interference. Fully supervised semantic segmentation algorithms have achieved state-of-the-art performance but rely on a large number of pixel-level labels, which are time-consuming and labor-consuming to produce. LayerCAM, an advanced weakly supervised semantic segmentation algorithm, can generate pixel-accurate results using only image-level labels, but its scattered and partially underactivated class activation regions degrade segmentation performance. In this paper, we propose a weakly supervised semantic segmentation method, continuous gradient class activation mapping(CAM) and its nonlinear multiscale fusion(continuous gradient fusion CAM). The method redesigns backpropagating gradients and nonlinearly activates multiscale fused heatmaps to generate more fine-grained class activation maps with an appropriate activation degree for different damage site sizes. Experiments on our dataset show that the proposed method can achieve segmentation performance comparable to that of fully supervised algorithms.

关键词： class activation maps laser-induced damage semantic segmentation weakly supervised learning

Palladium-catalyzed oxidative homocoupling of 2-arylquinazolinones

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Chinese Chemical Letters 2020年第12期31卷 3263-3266页

作者： Yadong Feng Zhengping Wu Ting Chen Qi Fu qihua you Jinhai Shen Xiuling Cui College of Einviranment and Public Health Xiamen Huaxia UniversityXiamen 361024China Research Center of Molecular Medicime Mdinistry of EducationKey Laboratory of Fujian Molecular MedicineKey laboratory of Precision Medicine and Molecular Dinghosis of Fujian UniversitiesKey Laboratory of Xiamen Marine and Cene DrugsSchool of Bionedical SciencsHuaqiao University Xiamen 361021China

Pd-catalyzed oxidative homocoupling of 2-arylquinazolinones was successfully developed for the direct construction of biaryls via C—H bond activation.New well-defined structure that possessed two quinazolinone units was obtained with high efficiency and atomic economy.The protocols offer an efficient approach to the synthetically useful and functionalized biaryls in good yields using quinazolinone as a directing group.

关键词： 2-Arylquinazolinones Homocoupling Palladium-catalyzed C—H bond activation