检索结果-南通市图书馆

Benzoyl cyanide, a general radical acylating reagent for photoredox-catalyzed benzylic site-selective acylation reactions

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

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

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

在线全文

学校读者我要写书评

暂无评论

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

在线全文

学校读者我要写书评

暂无评论

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

在线全文

学校读者我要写书评

暂无评论

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

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

Mastering air combat game with deep reinforcement learning

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第4期34卷 295-312页

作者： Jingyu zhu Minchi Kuang Wenqing Zhou Heng Shi Jihong zhu Xu Han Department of Precision Instruments Tsinghua UniversityBeijing 100084China Department of Computer Science and Technology Tsinghua UniversityBeijing 100084China Chengdu Aircraft Design&Research Institute Aviation Industry Corporation of ChinaChengdu 610000China

Reinforcement learning has been applied to air combat problems in recent years,and the idea of curriculum learning is often used for reinforcement learning,but traditional curriculum learning suffers from the problem of plasticity loss in neural *** loss is the difficulty of learning new knowledge after the network has *** this end,we propose a motivational curriculum learning distributed proximal policy optimization(MCLDPPO)algorithm,through which trained agents can significantly outperform the predictive game tree and mainstream reinforcement learning *** motivational curriculum learning is designed to help the agent gradually improve its combat ability by observing the agent's unsatisfactory performance and providing appropriate rewards as a ***,a complete tactical maneuver is encapsulated based on the existing air combat knowledge,and through the flexible use of these maneuvers,some tactics beyond human knowledge can be *** addition,we designed an interruption mechanism for the agent to increase the frequency of decisionmaking when the agent faces an *** the number of threats received by the agent changes,the current action is interrupted in order to reacquire observations and make decisions *** the interruption mechanism can significantly improve the performance of the *** simulate actual air combat better,we use digital twin technology to simulate real air battles and propose a parallel battlefield mechanism that can run multiple simulation environments simultaneously,effectively improving data *** experimental results demonstrate that the agent can fully utilize the situational information to make reasonable decisions and provide tactical adaptation in the air combat,verifying the effectiveness of the algorithmic framework proposed in this paper.

关键词： Air combat MCLDPPO Interruption mechanism Digital twin Distributed system

EGFR-targeted and gemcitabine-incorporated chemogene for combinatorial pancreatic cancer treatment

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第2期17卷 848-857页

作者： Miao Xie Qiushuang Zhang Yuanyuan Guo Lijuan zhu Xinyuan zhu Chuan Zhang School of Chemistry and Chemical Engineering Frontiers Science Center for Transformative MoleculesInstitute of Molecular MedicineSixth people’s HospitalSchool of MedicineShanghai Key Laboratory for Molecular Engineering of Chiral DrugsShanghai Jiao Tong UniversityShanghai 200240China Department of Radiology Shanghai Jiao Tong University Affiliated Sixth People’s HospitalSchool of MedicineShanghai Jiao Tong UniversityShanghai 200233China Institute of Molecular Medicine Shanghai Jiao Tong University Affiliated Renji HospitalSchool of MedicineShanghai Jiao Tong UniversityShanghai 200127China

Pancreatic cancer stands out as a recognized intractable tumor due to its high malignancy and mortality rates,which are largely attributed to the insensitivity of current clinical chemotherapies or *** chemo and gene therapy that integrates different therapeutic targets,may increase the chemosensitivity of pancreatic cancer and synergistically enhance the antitumor ***,conventional co-delivery of gene and chemo drugs is intensively dependent on complex nanoparticle delivery systems,thus would be limited by unstable drug packaging,nonspecific biodistribution,and biosafety ***,we rationally designed an epidermal growth factor-receptor(EGFR)-targeted and gemcitabine-incorporated oligonucleotide(termed as chemogene)with anti-Bcl-2 sequence,which achieves simple and precise integration of gemcitabine into a gene regulative agent,as well as the EGFR-targeted delivery for pancreatic cancer *** solid-phase synthesis,gemcitabine,as the first-line chemodrug for pancreatic cancer,is introduced to the antisense oligonucleotide to replace all cytosine nucleosides to obtain the gemcitabine-integrated chemogene(Ge-ASO^(Bcl-2)).Thereafter,Ge-ASO^(Bcl-2)is covalently coupled with EGFR nanobody to construct the final targeted chemogene without any exogenous ***,this nanobody-conjugated chemogene exhibits remarkable tumor targeting capability and antitumor effects both in vitro and in vivo,which initiates a first step toward the application of combinatorial chemo and gene therapy for future pancreatic cancer treatment.

关键词： antisense oligonucleotide chemogene nanobody drug delivery system pancreatic cancer