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Science China Chemistry 2024年第11期67卷 3833-3843页

作者： Zhaodong zhu Jingjing Wu Frontiers Science Center for Transformative Molecules Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs School of Chemistry and Chemical Engineering Zhangjiang Institute for Advanced Study Shanghai Jiao Tong University

Based on rational design, benzoyl cyanide, a well-known ionic acylating reagent, has been developed as a general radical acylating reagent for benzylic site-selective acylation reactions for the first time. Using visible-light photoredox-catalyzed single electron transfer(SET) and hydrogen atom transfer(HAT) strategies, two different direct benzylic C–H acylation reactions with high atom economy have been developed. This newly developed radical acylating reagent could also be used to achieve three component acyltrifluoromethylation of styrenes, which is usually challenging to achieve by other means. All of these reactions proceed under mild nickel-free and NHC-free conditions with high functional group tolerance. In addition, based on our detailed mechanistic experiments, the process of radical-radical cross-coupling mechanism was suggested for these transformations.

关键词： photoredox catalysis benzylic C–H acylation radical acylating reagent HAT catalysis acyltrifluoromethylation

UAV-assisted cooperative offloading energy efficiency system for mobile edge computing

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Digital Communications and Networks 2024年第1期10卷 16-24页

作者： Xue-yong yu Wen-Jin Niu ye zhu Hong-Bo zhu Jiangsu Key Laboratory of Wireless Communications Nanjing University of Posts and Telecommunications Nanjing210003China Engineering Research Centerof Health Service System Based on Ubiquitous Wireless Networks Ministry of EducationNanjng Universityof Posts and Telecommunications Nanjing210003China

Reliable communication and intensive computing power cannot be provided effectively by temporary hot spots in disaster areas and complex terrain ground *** this has greatly developed the application and integration of UAV and Mobile Edge Computing(MEC)to the Internet of Things(loT).However,problems such as multi-user and huge data flow in large areas,which contradict the reality that a single UAV is constrained by limited computing power,still *** to allowing UAV collaboration to accomplish complex tasks,cooperative task offloading between multiple UAVs must meet the interdependence of tasks and realize parallel processing,which reduces the computing power consumption and endurance pressure of *** the computing requirements of the user terminal,delay constraint of a computing task,energy constraint,and safe distance of UAV,we constructed a UAV-Assisted cooperative offloading energy efficiency system for mobile edge computing to minimize user terminal energy ***,the resulting optimization problem is originally nonconvex and thus,difficult to solve *** tackle this problem,we developed an energy efficiency optimization algorithm using Block Coordinate Descent(BCD)that decomposes the problem into three convex ***,we jointly optimized the number of local computing tasks,number of computing offloaded tasks,trajectories of UAV,and offloading matching relationship between multi-UAVs and multiuser *** results show that the proposed approach is suitable for different channel conditions and significantly saves the user terminal energy consumption compared with other benchmark schemes.

关键词： Computation offloading Internet of things(IoT) Mobile edge computing(MEC) Block coordinate descent(BCD)

A two-field-scan harmonic Hall voltage analysis for fast,accurate quantification of spin-orbit torques in magnetic heterostructures

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Science China(Physics,Mechanics & Astronomy) 2024年第10期67卷 105-112页

作者： Xin Lin Lijun zhu State Key Laboratory of Superlattices and Microstructures Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China College of Materials Science and Opto-Electronic Technology University of Chinese Academy of SciencesBeijing 100049China

We report on the development of a“two-field-scan”harmonic Hall voltage(HHV)analysis,which collects the second HHVas a function of a swept in-plane magnetic field at 45°and 0°relative to the excitation current,for the determination of the spin-orbit torques of transverse spins in magnetic heterostructures without significant perpendicular spins,longitudinal spins,and longitudinal/perpendicular Oersted *** demonstrate that this two-field-scan analysis is as accurate as the well-established but time-consuming angle-scan HHV analysis even in the presence of considerable thermoelectric effects but takes more than a factor of 7 less measurement *** also show that the fit of the HHV data from a single field scan at 0°,which is commonly employed in the literature,is not reliable because the employment of too many free parameters in the fitting of the very slowly varying HHV signal allows erroneous conclusion about the spin-orbit torque efficiencies.

关键词： spin-orbit torque spin current spin-orbit coupling spintronics

The recombinant jasmonate ZIM-domain(JAZ)protein functions as a novel insecticidal protein against Lepidopteran pests

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Science China(Life Sciences) 2024年第8期67卷 1777-1778页

作者： yuxian zhu Institute for Advanced Studies Wuhan UniversityWuhan 430072China

Lepidopterans,including butterflies and moths,make up one-tenth of all described agricultural pests on Earth,and many of them,such as fall armyworm,cotton bollworm,corn borer and rice leaf folder,are major agricultura... 详细信息

关键词： pests agricultural cotton

Structure and ion transport properties of organic ionic compounds revealed by NMR

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Magnetic Resonance Letters 2024年第2期4卷 2-12页

作者： Haijin zhu Guangdong Provincial Key Laboratory of Materials and Technologies for Energy Conversion Guangdong Technion-Israel Institute of TechnologyShantou515063China

Organic ionic plastic crystals(OIPCs)are emerging as an important material family for solid-state electrolytes and many other *** have significant advantages over conventional electrolyte materials,such as high ionic conductivity,non-flammability.and *** nuclear magnetic resonance(NMR)spectroscopy techniques including solid-state NMR,pulsed-field gradient(PFG)NMR,and magnetic resonance imaging(MRI)etc.,provide us a versatile toolkit to understand the fundamental level structures,molecular dynamics,and ionic interactions in these *** article reviews the commonly used NMR methods including solid-and solution-state NMR,PFG-NMR,dynamic nuclear polarization(DNP)and the application of these methods in revealing the microscopic level structures and ion-transport mechanisms in OIPC materials.

关键词： NMR Electrolyte Organic ionic plastic crystals Defects Diffusion Microstructure

A Second-Order Image Denoising Model for Contrast Preservation

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Communications on Applied Mathematics and Computation 2024年第2期6卷 1406-1427页

作者： Wei zhu Department of Mathematics University of AlabamaBox 870350TuscaloosaAL35487USA

In this work,we propose a second-order model for image denoising by employing a novel potential function recently developed in zhu(J Sci Comput 88:46,2021)for the design of a regularization *** to this new second-order derivative based regularizer,the model is able to alleviate the staircase effect and preserve image *** augmented Lagrangian method(ALM)is utilized to minimize the associated functional and convergence analysis is established for the proposed *** experiments are presented to demonstrate the features of the proposed model.

关键词： Image denoising Variational model Image contrast Augmented Lagrangian method(ALM)

Modulating the degree of O vacancy defects to achieve selective control of electrochemical CO_(2) reduction products

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Chinese Chemical Letters 2024年第5期35卷 482-486页

作者： Tianbo Jia Lili Wang Zhouhao zhu Baikang zhu yingtang Zhou Guoxing zhu Mingshan zhu Hengcong Tao School of Petrochemical Engineering&Environment Zhejiang Ocean UniversityZhoushan 316022China Department of General Practice First Medical CenterChinese PLA General HospitalBeijing 100853China National&Local Joint Engineering Research Center of Harbor Oil&Gas Storage and Transportation Technology Zhoushan 316022China School of Chemistry.and Chemical Engineering Jiangsu UniversityZhenjiang 212013China Guangdong Key Laboratory of Environmental Pollution and Health School of EnvironmentJinan UniversityGuangzhou 511443China

Conversion of CO_(2) into high-value products using electrochemical CO_(2) reduction(ECR)technology is an effective way to alleviate global warming and reach carbon *** oxygen vacancies in heterogenous catalysis are generally considered as a powerful method to enhance the performance of ECR by promoting CO_(2) adsorption and ***,the extent of defects in oxygen vacancies-activity relation has rarely been ***,we prepared Cu-Cd bimetallic catalysts with adjustable oxygen defect degree by controlling the amount of cadmium *** transform infrared spectroscopy characterization results reveal that the formation of oxygen vacancies is attributed to the asymmetric stretching of Cu-O by the addition of *** results show that the oxygen defect degree can modulate the selectivity of ECR products.A low degree of oxygen defects(CuO)is generally associated with lower product Faraday efficiency(FE_(C2)/FE_(C1)≈114%),but overabundant oxygen vacancies(CuO_(2.625)-CdO_(0.375))are not entirely favorable to improving ECR activity(FE_(C2)/FE_(C1)≈125%)and single selectivity,while an appropriate degree of oxygen vacancies(CuO_(2.75)-CdO_(0.25))can facilitate the ECR process toward single product selective production(FE_(C2)/FE_(C1)≈296%).The theoretical calculation showed that the O vacancy formed on CuO and the interface between CdO and CuO were conducive to enhancing the formation of ^(*)COOH intermediate and promoting the generation of ethylene *** study provides a new approach and insight into the selective production of single products for future industrial applications of ECR.

关键词： CO_(2) O-vacancies Bimetallic catalysts Copper oxide Cadmium oxide Selective

Efficacy.and safety of over-the-scope-clips in the therapy of acute nonvariceal upper gastrointestinal bleeding:Meta-analysis

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World Journal of Clinical Cases 2024年第21期12卷 4680-4690页

作者： Xue-zhu yang Dan-Li yu zhi Wang zhi-Long Gao Department of Gastroendoscopy Renmin HospitalHubei University of MedicineShiyan 442000Hubei ProvinceChina Department of Gastrointestinal Medicine III Renmin HospitalHubei University of MedicineShiyan 442000Hubei ProvinceChina

BACKGROUND Acute nonvariceal upper gastrointestinal bleeding(ANVUGIB)is a frequent lifethreatening acute condition in gastroenterology associated with high morbidity.and ***-the-scope-clip(OTSC)is a new endoscopic hemostasis technique,which is being used in ANVUGIB and is more *** To summarize and analyze the effects of the OTSC in prevention of recurrent bleeding,clinical success rate,procedure time,hospital stay.and adverse events in the treatment of ANVUGIB,to evaluate whether OTSC can replace standard endoscopic therapy as a new generation of treatment for *** The literature related to OTSC and standard therapy for ANVUGIB published before January 2023 was searched in PubMed,Web of Science,EMBASE,Cochrane,Google,and CNKI *** in recurrent bleeding(7 or 30 days),clinical results(clinical success rate,conversion rate to surgery,mortality),therapy time(procedure time,hospital stay),and adverse events in the OTSC intervention group were summarized and analyzed,and the MD or OR of 95%CI is calculated by Review Manager *** This meta-analysis involved 11 studies with 1266 *** risk of bias was *** patients in the OTSC group,7-and 30-days recurrent bleeding rates,as well as procedure time,hospital stay.and intensive care unit stay,were greatly *** could significantly improve the clinical success rate of *** therapy did not cause serious adverse and was effective in reducing patient *** OTSC may provide more rapid and sustained hemostasis,and thus,promote recovery.and reduce mortality in patients with *** addition,the safety of OTSC is assured.

关键词： Acute nonvariceal upper gastrointestinal bleeding Over-the-scope-clips Recurrent bleeding Adverse events Meta-analysis

Synthesis of highly stable Ni nanoparticles via electrostatic self-assembly for enhanced hydrogen storage of MgH_(2)

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Rare Metals 2024年第9期43卷 4356-4366页

作者： Qin-Ke Tang Jiang-Chuan Liu Rui Shi yun-Feng zhu Ji-Guang Zhang ya-Na Liu Jun Wang yao Zhang Xiao-Hui Hu zhi-Bin Liu Li-Quan Li College of Materials Science and Engineering Jiangsu Collaborative Innovation Centre for Advanced Inorganic Function CompositesNanjing Tech UniversityNanjing 211816China School of Materials Science and Engineering Southeast UniversityNanjing 211189China

Magnesium-based hydrides have been widely recognized as an appropriate choice for solid-state hydrogen ***,its undesirable thermodynamics and sluggish hydrogenation/dehydrogenation kinetics are major bottlenecks for its ***,a highly stable and highly dispersed Ni-based catalyst(Ni/Al_(2)O_(3)/GN)was fabricated to promote the hydrogen storage performance of MgH_(2)via the electrostatic effect of NiAl-LDH/GN precursor with a co-calcination reduction ***_(2)-5wt%Ni/Al_(2)O_(3)/GN exhibits excellent hydrogen storage performance,releasing about 5.7 wt%hydrogen in 3500 s at 250℃,and can reach a saturation hydrogen absorption of about 6.15 wt%in 3000 s at 100℃.Furthermore,it also shows low dehydrogenation apparent activation energy of 89.1 and 118.2 kJ·mol^(-1).Impressively,the catalyst ensures the stability of both the physical phase and structure during ball milling and cycling *** role of each phase in Ni/Al_(2)O_(3)/GN on the hydrogen storage performance of MgH_(2)was also discussed through experiments and theoretical calculation,and the synergistic catalytic mechanism of Ni/Al_(2)O_(3)/GN was clearly *** work provides a unique perspective for the preparation of highly stable and highly dispersible catalysts.

关键词： Magnesium hydride Ni/Al_(2)O_(3)/GN Hydrogen storage performance Catalytic mechanism

Confined Mn^(2+) enables effective aerobic oxidation catalysis

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Science China Chemistry 2024年第5期67卷 1545-1553页

作者： Desheng y.an Sicong Ma Xiao Kong Chi Zhang Lin Chen Chengsheng yang Lihua Wang Zhen Liu Lin ye yongmei Liu Rui Ma zhi-Pan Liu yifeng zhu yong Cao Xinhe Bao Department of Chemical Physics University of Science and Technology of ChinaHefei 230026China Department of Chemistry Shanghai Key Laboratory of Molecular Catalysis and Innovative MaterialsCollaborative Innovation Center of Chemistry for Energy MaterialsFudan UniversityShanghai 200438China Key Laboratory of Synthetic and Self-Assembly Chemistry for Organic Functional Molecules Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China School of Materials and Chemistry University of Shanghai for Science and TechnologyShanghai 200093China Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204China Institute of Advanced Fluorine-Containing Materials Zhejiang Normal UniversityJinhua 321004China State Key Laboratory of Catalysis National Laboratory for Clean EnergyCollaborative Innovation Center of Chemistry for Energy MaterialsDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China

Effective and mild activation of O_(2) is essential but challenging for aerobic oxidation. In heterogeneous catalysis, high-valence manganese oxide(e.g., +4) is known to be active for the oxidation, whereas divalent MnO is ineffective due to its limited capacity to supply surface oxygen and its thermodynamically unstable structure when binding O_(2) in reaction conditions. Inspired by natural enzymes that rely on divalent Mn^(2+), we discovered that confining Mn^(2+) onto the Mn_(2)O_(3) surface through a dedicated calcination process creates highly active catalysts for the aerobic oxidation of 5-hydroxymethylfurfural, benzyl alcohol, and *** Mn_(2)O_(3)-confined Mn^(2+) is undercoordinated and efficiently mediates O_(2) activation, resulting in 2–3 orders of magnitude higher activity than Mn_(2)O_(3) alone. Through low-temperature infrared spectroscopy, we distinguished low-content Mn^(2+) sites at Mn_(2)O_(3) surface, which are difficult to be differentiated by X-ray photoelectron spectroscopy. The combination of in-situ energydispersive X-ray absorption spectroscopy.and X-ray diffraction further provides insights into the formation of the newly identified active Mn^(2+) sites. By optimizing the calcination step, we were able to increase the catalytic activity threefold *** finding offers promising frontiers for exploring active oxidation catalysts by utilizing the confinement of Mn^(2+)and oftenignored calcination skills.

关键词： confinement catalysis manganese oxide aerobic oxidation divalent Mn^(2+) operando spectroscopies