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Cu（I）-Catalyzed Asymmetric Cross-Coupling of N-Tosylhydrazones and Trialkyl- silylethynes： Enantioselective Construction of C（sp）--C（sp^3） Bonds

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Chinese Journal of Chemistry 2018年第3期36卷 217-222页

作者： Wen-Dao Chu Fangfang Guo Lefei Yu junting hong qianyi Liu Fanyang Mo Yan Zhang Jianbo Wang Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province College of Chemistry & Chemical Engineering China West Normal University Nanchon8 Sichuan 637002 China Beijing National Laboratory of Molecular Sciences (BNLMS) and Key Laboratory of Bioorganic Chemistry arid Molecular Engineering of Ministry of Education College of Chemistry Peking University Beijing 100871 China

The first catalytic enantioselective C（sp）-C（sp^3） cross-coupling reaction between N-tosylhydrazones and trialkylsilylethynes in the presence of Cu（I） salts and chiral phosphoramidite ligands was developed. A series of svnthetically interesting, functionalized alkynes were obtained with moderate to good enanttiselectivities （up to 83% ee）. Cu（ll） carbene migratory insertion is proposed to be the enantio-determining step. KEYWORDS C（sp）--C（sp^3） cross-coupling, metal carbene, asymmetric catalysis, Cu（I） catalysts, N-tosylhydrazones

关键词： C(sp)--C(sp^3) cross-coupling metal carbene asymmetric catalysis Cu(I) catalysts N-tosylhydrazones

Electrochemical Radical Borylation of Aryl Iodides

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Chinese Journal of Chemistry 2019年第4期37卷 347-351,I0002页

作者： junting hong Qianyi Liu Feng Li Guangcan Bai Guoquan Liu Man Li Onkar S.Nayal Xuefeng Fu Fanyang Mo Department of Energy and Resources Engineering College of EngineeringPeking UniversityBeijing 100871China State Key Laboratory of Natural and Biomimetic Drugs School of Pharmaceutical SciencesPeking UniversityBeijing 100871China Department of Biomedical Engineering College of EngineeringPeking UniversityBeijing 100871China Jiangsu Donghai Silicon Industry S&T Innovation Center Jiangsu Weiming Environmental Protection S&T Co.Ltd.No.38Guangming RdDonghai CountyJiangsu 222300China

Herein,we report the first electrochemical strategy for the borylation of aryl iodides via a radical pathway using current as a driving force.A mild reaction condition allows an assorted range of readily available aryl iodides to be proficiently converted into synthetically valuable arylboronic esters under transition metal catalyst-free ***,this method also shows good functional group *** control mechanistic experiments reveal the formation of aryl radical as a key intermediate and the current plays an important role in the generation of radical intermediate.

关键词： Electrochemical Radical Borylation Aryl Iodides proficiently converted

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MMU月面起飞燃耗最省轨迹和推力设计研究

动力学与控制学报 2021年第6期19卷 8-15页

作者：韩艳铧洪军停张勇南京航空航天大学航天学院南京211106 南京航空航天大学无人机研究院南京211106 南京航空航天大学无人机先进技术工业和信息化部重点实验室南京210016

载人机动装置(MMU)携载航天员在月面机动飞行包括上升转弯段、巡飞段、转弯下降段,本文研究上升转弯段燃耗最省轨迹和主发动机推力优化问题.首先采用Pontryagin极小值原理,推导出MMU发动机推力大小和方向的最优函数形式.结果表明,推力... 详细信息

载人机动装置(MMU)携载航天员在月面机动飞行包括上升转弯段、巡飞段、转弯下降段,本文研究上升转弯段燃耗最省轨迹和主发动机推力优化问题.首先采用Pontryagin极小值原理,推导出MMU发动机推力大小和方向的最优函数形式.结果表明,推力大小是开关形式,且最多切换一次,故只需用"开"和"关"持续时间两个参数描述;推力方向角的余切是时间的仿射函数,只需用该函数的斜率和截距两个参数描述.上升转弯段和巡飞段交接,故上升转弯段的末状态受飞行高度、速度大小和方向三个条件约束,这样就将燃耗最省最优控制问题转化为三等式约束下的四参数非线性规划问题,设计自由度仅为一,只需用单自由度搜索即可快速求解.数值仿真验证了本文所提方法的有效性.

关键词：月面低空机动飞行载人机动装置(MMU) 燃耗最省最优控制最优轨迹

Synthesis of Donor-Acceptorπ-Conjugated Macrocycles by Post-Functionalization

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Chinese Journal of Chemistry 2021年第10期39卷 2705-2710页

作者： junting Wang Qingyun Wan Junzhi Liu Department of Chemistry and State Key Laboratory of Synthetic Chemistry The University of Hong KongPokfulam RoadHong KongChina

Main observation and conclusion In this paper,two novel donor-acceptor(D-A)macrocyclic compounds 5 and 7 were successfully synthesized by post-functionalization of a planar dimer macrocycle(1)and a highly twisted trimer macrocycle(2),respectively,via controllable oxidation of methoxy groups and condensation between diketones and phenylenediamine in *** with unembellished 9,10-dimethoxyphenanthrene,the resultant dibenzo[a,c]phenazine motif is electron-deficient rather than electron-rich,yielding two D-Aπ-conjugated macrocycles with more contractive energy *** functional theory(DFT)calculations further support the unequivocal evidence of the D-A properties of macrocycles 5 and *** difference of their photophysical properties was investigated by the aid of ultraviolet-visible absorption and fluorescence ***,the stacking patterns of 7 and its contrastπ-conjugated macrocycle trimer(2)were compared via the analysis of X-ray single crystal,in which the electron-deficient dibenzo[a,c]phenazine unit provides extra interaction sites,resulting in orderly arrangement of 7 in the solid state.

关键词： Macrocycles Post-functionalization Donor-acceptor systems Oxidation Stacking interactions

Sulfur-substitution-enhanced crystallization and crystal structure of poly(trimethylene monothiocarbonate)

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Chinese Chemical Letters 2022年第2期33卷 1021-1024页

作者： Xiaohan Cao hongliang Wang Jialiang Yang Ruiyang Wang Xin hong Xinghong Zhang junting Xu Hai Wang MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and EngineeringZhejiang UniversityHangzhou 310027China Center of Chemistry for Frontier Technologies Zhejiang UniversityHangzhou 310027China Department of Chemistry Zhejiang UniversityHangzhou 310027China Department of Polymer Science and Engineering College of Chemical EngineeringDalian University of TechnologyDalian 116024China

In this paper,the crystallization behavior of a novel poly(monothiocarbonate),poly(trimethylene monothiocarbonate)(PTMMTC),was investigated and compared with its polycarbonate analogue,poly(trimethylene carbonate)(PTMC).It is found that PTMMTC exhibits strong crystallizability,while un-stretched PTMC is *** and DMA results reveal that PTMMTC possesses higher glass transition temperature(T_(g))andβ-transition temperature(T_(β))than *** based on density functional theory(DFT)shows that,the bond angle of C-S-C is evidently smaller than that of C-O-C,and thus a larger dipole *** leads to the stronger intermolecular interaction and more rigid chain confor-mation in PTMMTC,which is the origin of sulfur-substitution enhanced *** crystal struc-ture of PTMMTC was preliminarily determined for the first *** has an orthorhombic crystal structure with a planar zig-zag chain *** parameters of unit cell are a=10.74 A,b=4.79 A,and c(fiber axis)=7.74 A.

关键词： Poly(monothiocarbonate) Polycarbonate Crystallization behavior Crystal structure Sulfur substitution enhanced crystallization

Spectrum Usage Anomaly Detection from Sub-Sampled Data Stream via Deep Neural Network

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Journal of Communications and Information Networks 2023年第1期8卷 13-23页

作者： Han Zhang Jian Yang junting Chen Yue Gao Institute for Communication Systems the University of SurreyGuildford GU27XHUK Mobile Communications Innovation Center China Academy of Information and Communications TechnologyBeijing 100191China Future Network Intelligence Institute(FNii)and School of Science and Engineering the Chinese University of Hong KongShenzhen 518172China School of Computer Science Fudan UniversityShanghai 200433China.Institute for Communication Systemsthe University of SurreyGuildford GU27XHUK

Anomaly detection is an essential part of any practical system in order to remedy any malfunction and accident early to create a secure and robust *** users and malfunctioning cognitive radio(CR)devices may cause severe interference to legitimate ***,there are no effective methods to detect spontaneous and irregular anomaly behaviors in sub-sampling data stream from wideband compressive spectrum sensing as an important function of a CR *** this article,to detect anomaly utilization of spectrum from sub-sampled data stream,a multiple layer perceptron/feed-forward neural network(FFNN)based solution is *** proposed solution would learn the pattern of legitimate and anomalous usages autonomously without expert's *** proposed neural network(NN)framework has also shown benefits such as more than 80%faster detection speed and lower detection error rate.

关键词： compressive sensing(CS) machine learning(ML) multicoset sampling anomaly detection

Online search for UAV relay placement for free-space optical communication under shadowing

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Intelligent and Converged Networks 2023年第1期4卷 28-40页

作者： Yuanshuai Zheng Yinjun Wang junting Chen School of Science and Engineering and the Future Network of Intelligence Institute(FNii) The Chinese University of Hong KongShenzhen 518172China

Unmanned aerial vehicle(UAV)relaying is promising to overcome the challenge of signal blockage in free-space optical(FSO)communications for users in dense urban *** works on UAV relay placement are mostly based on simplified line-of-sight(LOS)channel models or probabilistic channel models,and thus fail to capture the actual LOS status of the optical communication *** contrast,this paper studies three-dimensional(3D)online placement for a UAV to construct relay links to two ground users in deep shadow with LOS *** analyzing the properties of the UAV relay placement problem,it is found that searching on a plane that approximates the equipotential surface can achieve a good performance and complexity trade-off for a good placement of the UAV relay in *** on these insights,a two-stage online search algorithm on an equipotential plane(TOSEP)is developed for a special case where the equipotential surface turns out to be an equipotential *** the general case,a strategy called gradient projected online search algorithm on an approximated equipotential plane(GOSAEP)is developed,which approximates the equipotential surface with a perpendicular plane using the gradient projection *** experiments are conducted over a real-world city topology,and it is shown that the GOSAEP achieves over 95%of the performance of the exhaustive 3D search scheme within a 300-m search length.

关键词： free-space optical communication relay communication unmanned aerial vehicle(UAV) trajectory design capacity maximization

Channel Knowledge Map(CKM)-Assisted Multi-UAV Wireless Network:CKM Construction and UAV Placement

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Journal of Communications and Information Networks 2023年第3期8卷 256-270页

作者： Haoyun Li Peiming Li Gaoyuan Cheng Jie Xu junting Chen Yong Zeng School of Science and Engineering and the Future Network of Intelligence Institute(FNii)the Chinese University of Hong KongShenzhenShenzhen 518172China National Mobile Communications Research Laboratory and Frontiers Science Center for Mobile Information Communication and Security the Southeast UniversityNanjing 210096the Purple Mountain LaboratoriesNanjing 211111China

Channel knowledge map(CKM)has recently emerged as a viable new solution to facilitate the placement and trajectory optimization for unmanned aerial vehicle(UAV)communications,by exploiting the siteand location-specific radio propagation *** paper investigates a CKM-assisted multi-UAV wireless network,by focusing on the construction and utilization of CKMs for multi-UAV placement ***,we consider the CKM construction problem when data measurements for only a limited number of points are *** this end,we exploit a data-driven interpolation technique,namely the Kriging method,to construct CKMs to characterize the signal propagation ***,we study the multi-UAV placement optimization problem by utilizing the constructed CKMs,in which the multiple UAVs aim to optimize their placement locations to maximize the weighted sum rate with their respectively associated ground base stations(GBSs).However,the weighted sum rate function based on the CKMs is generally non-differentiable,which renders the conventional optimization techniques relying on function derivatives *** tackle this issue,we propose a novel iterative algorithm based on derivative-free optimization,in which a series of quadratic functions are iteratively constructed to approximate the objective function under a set of interpolation conditions,and accordingly,the UAVs’placement locations are updated by maximizing the approximate function subject to a trust region ***,numerical results are presented to validate the performance of the proposed *** is shown that the Kriging method can construct accurate CKMs for ***,the proposed derivative-free placement optimization design based on the Kriging-constructed CKMs achieves a weighted sum rate that is close to the optimal exhaustive search design based on ground-truth CKMs,but with much lower implementation *** addition,the proposed design is shown to significant

关键词： UAV communications CKM CKM construction UAV placement derivative-free optimization

Modeling study on the roles of the deposition and transport of PM_(2.5) in air quality changes over central-eastern China

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Journal of Environmental Sciences 2023年第1期123卷 535-544页

作者： Lei Zhang Jianjun He Sunling Gong Xiaomei Guo Tianliang Zhao Huizheng Che hong Wang Chunhong Zhou Jingyue Mo Ke Gui Yu Zheng Lei Li junting Zhong Xiaoye Zhang State Key Laboratory of Severe Weather&Key Laboratory of Atmospheric Chemistry of CMA Chinese Academy of Meteorological SciencesBeijing 100081China Heavy Rain and Drought-Flood Disasters in Plateau and Basin Key Laboratory of Sichuan Province Chengdu 610072China Weather Modification Office of Sichuan Province Chengdu 610072China Climate and Weather Disasters Collaborative Innovation Center Nanjing University of Information Science&TechnologyNanjing 210044China

The role of PM_(2.5)(particles with aerodynamic diameters≤_(2.5)μm)deposition in air quality changes over China remains *** using the three-year(2013,2015,and 2017)simulation results of the WRF/CUACE v1.0 model from a previous work(Zhang et al.,2021),a non-linear relationship between the deposition of PM_(2.5)and anthropogenic emissions over central-eastern China in cold seasons as well as in different life stages of haze events was ***_(2.5)deposition is spatially distributed differently from PM_(2.5)concentrations and anthropogenic emissions over *** North China Plain(NCP)is typically characterized by higher anthropogenic emissions compared to southern China,such as the middlelow reaches of Yangtze River(MLYR),which includes parts of the Yangtze River Delta and the ***,PM_(2.5)deposition in the NCP is significantly lower than that in the MLYR region,suggesting that in addition to meteorology and emissions,lower deposition is another important factor in the increase in haze *** transport of pollution in central-eastern China acts as a moderator of pollution levels in different regions,for example by bringing pollution from the NCP to the MLYR region in cold *** was found that in typical haze events the deposition flux of PM_(2.5)during the removal stages is substantially higher than that in accumulation stages,with most of the PM_(2.5)being transported southward and deposited to the MLYR and Sichuan Basin region,corresponding to a latitude range of about 24°N-31°N.

关键词： PM_(2.5) Deposition Regional transport China WRF/CUACE v1.0 model