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Photocatalyzed ditrifluoromethylthiolation of alkenes with CF_(3)SO_(2)Na

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Science China Chemistry 2024年第2期67卷 587-594页

作者： Fangming chen Lvqi Jiang Chunyang Hu Jie Liu Wenbin yi School of Chemistry and Chemical Engineering Nanjing University of Science and TechnologyNanjing210094China Key Laboratory of Organofluorine Chemistry Shanghai Institute Organic ChemistryChinese Academy of SciencesShanghai200032China

Since the first report of sodium trifluoromethanesulfinate(CF_(3)SO_(2)Na) as an electrophilic trifluoromethylthiolation reagent in 2015,there has been no breakthrough in research in this ***,we disclose an unprecedented usage of CF_(3)SO_(2)Na as a radical trifluoromethylthiolation reagent.A photocatalyzed ditrifluoromethylthiolation of alkenes with CF_(3)SO_(2)Na in the presence of PPh_(3) and catalytic copper has been ***,either Ir[(p-Fppy)_(2)(bpy)]PF_6 or Ir(ppy)_(3) could facilitate this *** studies indicate that initiation of the radical chain proceeded via two different photocatalytic quenching *** protocol provides a practical method for the construction of diverse vicinal ditrifluoromethylthiolated compounds.

关键词： trifluoromethylthiolation photocatalysis radical difunctionalization alkenes

Chain Extender-induced Hydrogen Bonding Organization Determines the Morphology and Properties of Thermoplastic Polycarbonate Polyurethane

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Chinese Journal of Polymer Science 2024年第1期42卷 87-96,I0009页

作者： yi-Lang Qin Ping Zhu chen-Xi Ouyang Xia Dong Fuwai Hospital Chinese Academyof Medical Sciences&Peking Union Medical College/National Center for Cardiovascular DiseasesBejing 100037China CASKey Laboratoryof Engineering Plastics CAS Research/Education Centerfor Excellence in Molecular SciencesInstitute ofChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

Thermoplastic polycarbonate polyurethanes(PCUs) are multiblock copolymers that have been applied for medical devices for long time. Aliphatic diols are common chain extenders(CE) involved in the composition of the hard segments of PCU. However, limited knowledge was discovered about how the chemical structure of CE affects the hydrogen bonding organization within PCUs and their mechanical *** investigate this problem, a group of PCUs were synthesized respectively by extending the polymer chain with 1,4-butanediol(BDO),aminoethanol(MEA), ethanediol(EO) as three kinds of chain extenders. Tiny differences in the CE chemical structure results in remarkable variations in phase separation, condensed morphologies, thermal and mechanical properties, which are characterized by Fourier transform infrared spectrometer, atomic force microscopy, small-angle X-ray scattering, differential scanning calorimetry, and tensile tests. The microstructural evolution during unilateral deformation and the different mechanism induced by the different CEs was probed and unveil by in situ wide-and small-angle X-ray diffraction. Symmetry of CE can improve the organization of the hydrogen bonding. The coherence strength of the urethane/urea group also plays a key role by comparing the two PCUs with ethanediol and aminoethanol.

关键词： Thermoplastic polycarbonate polyurethane Chain extender Hydrogen bonding Mechanical properties

Distributed Economic MPC for Synergetic Regulation of the Voltage of an Island DC Micro-Grid

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IEEE/CAA Journal of Automatica Sinica 2024年第3期11卷 734-745页

作者： yi Zheng Yanye Wang Xun Meng Shaoyuan Li Hao chen IEEE the Department of Automation Shanghai Jiao Tong UniversityShanghai 200240 the Key Laboratory of System Control and Information Processing Ministry of Education of ChinaShanghai 200240China Haixi Institutes Chinese Academy of SciencesJinjiang 362216China

In this paper,distributed model predictive control(DMPC) for island DC micro-grids(MG) with wind/photovoltaic(PV)/battery power is proposed,which coordinates all distributed generations(DG) to stabilize the bus voltage together with the insurance of having computational efficiency under a real-time *** on the feedback of the bus voltage,the deviation of the current is dispatched to each DG according to cost over the prediction ***,to avoid the excessive fluctuation of the battery power,both the discharge-charge switching times and costs are considered in the model predictive control(MPC) optimization problems.A Lyapunov constraint with a time-varying steady-state is designed in each local MPC to guarantee the stabilization of the entire *** voltage stabilization of the MG is achieved by this strategy with the cooperation of *** numeric results of applying the proposed method to a MG of the Shanghai Power Supply Company shows the effectiveness of the distributed economic MPC.

关键词： Distributed model predictive control(DMPC) Lyapunovbased model predictive control micro-grid(MG) voltage control

Unidirectional propagation of water waves near ancient Luoyang Bridge

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Frontiers of physics 2024年第3期19卷 167-174页

作者： Linkang Han Qilin Duan Junliang Duan Shan Zhu Shiming chen Yuhang yin Huanyang chen Shenzhen Research Institute of Xiamen University Shenzhen 518000China Department of Physics Xiamen UniversityXiamen 361005China Key Laboratory of Underwater Acoustic Communication and Marine Information Technology of the Ministry of Education Xiamen UniversityXiamen 361005China

Metasurfaces and metagratings offer new platforms for electromagnetic wave control with significant ***,metasurfaces based on abrupt phase change and resonant structures suffer from the drawback of high loss and face challenges when applied in water ***,the application of metasurfaces in water wave control is not ideal due to the limitations associated with high loss and other *** have discovered that non-resonant metagratings exhibit promising effects in water wave *** the similarity between bridges and metagratings,we have successfully developed a water wave metagrating model inspired by the ancient Luoyang Bridge in *** conduct theoretical calculations and simulations on the metagrating and derive the equivalent anisotropic model of the *** model provides evidence that the metagrating has the capability to control water waves and achieve unidirectional surface water *** accuracy of our theory is strongly supported by the clear observation of the unidirectional propagation phenomenon during simulation and experiments conducted using a reduced version of the *** is the first time that the unidirectional propagation of water waves has been seen in water wave metagrating *** all,we realize the water wave metagrating experiment for the first *** combining complex gratings with real bridges,we explore the physics embedded in the ancient building—Luoyang Bridge,which are of great significance for the water wave metagrating design and provide a new method for analyzing the effects of water waves on *** the same time,this discovery also provides a new idea for ocean cargo transportation,ocean garbage cleaning,and the development and protection of ancient bridges.

关键词： Luoyang Bridge unidirectional propagation water wave metagratings equivalent anisotropic model

Excellent alkali resistance of Fe,Ce and sulfates co-modified V_(2)O_(5)-WO_(3)/TiO_(2) catalyst for selective catalytic reduction of NO_(x) with NH_(3)

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Journal of Rare Earths 2024年第9期42卷 1682-1692,I0002页

作者： Biyi Huang Xianfang yi Jianyi Zhang Yuqiu Liu Yanting chen Jinsheng chen Jinxiu Wang Center for Excellence in Regional Atmospheric Environment and Key Lab of Urban Environment and HealthInstitute of Urban EnvironmentChinese Academy of SciencesXiamen361021China College of Resources and Environment Fujian Agriculture and Forestry UniversityFuzhou350002China Fujian Key Laboratory of Atmospheric Ozone Pollution Prevention Institute of Urban EnvironmentChinese Academy of SciencesXiamen361021China University of Chinese Academy of Sciences Beijing100049China

Improving the alkali resistance of catalysts for selective catalytic reduction of NO_(x) with NH_(3) is still a *** this work,the co-modification with Fe,Ce and sulfates on V_(2)O_(5)-WO_(3)/TiO_(2) catalysts(denoted as xSFeCeVWTi) significantly enhances its alkali resistance with K element as a representative.A series of xSFeCeVWTi catalysts was synthesized by wet impregnation with designed 0.05Fe/V, 1.5Ce/V and different S/V molar ratios *** NO_(x) conversion and K resistance of xSFeCeVWTi catalysts increase with the increase of loading amounts of sulfates but no longer further increase as the sulfates load is excessive to block the pores of catalysts and hinder the adsorption of *** optimal modified catalyst in about 2.2S/V actual loading ratio,corresponding to 10.5SFeCeVWTi sample,shows over 99.0%NO_(x) conversion and N_(2) selectivity at 300-400℃ after *** interaction between Fe,Ce and V improves its redox ability but slightly weakens surface acidity,while the proper amount of sulfate species enriches surface Br?nsted acid sites but attenuates its redox ***,a balance of redox capacity and surface acidity,caused by Fe,Ce and sulfate co-modification,contributes to the excellent K resistance of 10.5SFeCeVWTi ***,the change of physicochemical properties influences the reaction mechanism which follows the Eley-Rideal mechanism on *** *** results show that the co-modification with Fe,Ce and sulfates is a good way to improve the alkali tolerance of V_(2)O_(5)-WO_(3)/TiO_(2) catalyst in industrial applications.

关键词： SCR CeO_(2) Fe_(2)O_(3) SO_(4)^(2-) K resistance K poisoning

A blockchain-empowered authentication scheme for worm detection in wireless sensor network

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Digital Communications and Networks 2024年第2期10卷 265-272页

作者： Yuling chen Xiong Yang Tao Li yi Ren Yangyang Long State Key Laboratory of Public Big Data College of Computer Science and TechnologyGuizhou UniversityGuiyang550025China School of Computing Science University of East AngliaNorwichNR57TJUK

Wireless Sensor Network(WSN)is a distributed sensor network composed a large number of nodes with low cost,low performance and *** special structure of WSN brings both convenience and *** example,a malicious participant can launch attacks by capturing a physical ***,node authentication that can resist malicious attacks is very important to network ***,blockchain technology has shown the potential to enhance the security of the Internet of Things(IoT).In this paper,we propose a Blockchain-empowered Authentication Scheme(BAS)for *** our scheme,all nodes are managed by utilizing the identity information stored on the ***,the simulation experiment about worm detection is executed on BAS,and the security is evaluated from detection and infection *** experiment results indicate that the proposed scheme can effectively inhibit the spread and infection of worms in the network.

关键词： Wireless Sensor Network(WSN) Node authentication Blockchain Tangle Worm detection

Rapid Unconscious Acquisition of Conditioned Fear with Low-Spatial-Frequency but Emotionally Neutral Stimuli

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Research 2024年第1期2023卷 753-762页

作者： Yujie chen Si chen Zhongju Sun Xilei Zhang Xiangyong Yuan Liang Wang yi Jiang State Key Laboratory of Brain and Cognitive Sciences CAS Center for Excellence in Brain Science and Intelligence TechnologyInstitute of PsychologyChinese Academy of SciencesBeijing 100101China Department of Psychology University of Chinese Academy of SciencesBeijing 100049China Chinese Institute for Brain Research Beijing 102206China CAS Key Laboratory of Mental Health Institute of PsychologyChinese Academy of SciencesBeijing 100101China

It has long been proposed that emotionally“prepared”(i.e.,fear-related)stimuli are privileged in the unconscious acquisition of conditioned ***,as fear processing is suggested to highly depend on the coarse,low-spatial-frequency(LSF)components of the fear-related stimuli,it is plausible that LSF may play a unique role in the unconscious fear conditioning even with emotionally neutral ***,we provided empirical evidence that,following classical fear conditioning,an invisible,emotionally neutral conditioned stimulus(CS+)with LSF,but not with high spatial frequency(HSF),can rapidly elicit stronger skin conductance responses(SCRs)and larger pupil diameters than its CS−*** comparison,consciously perceived emotionally neutral CS+with LSF and HSF elicited comparable *** together,these results support that the unconscious fear conditioning does not necessarily entail emotionally prepared stimuli but prioritizes LSF information processing and highlight the crucial distinctions between the unconscious and the conscious fear *** findings not only coincide with the postulation that a rapid,spatial-frequency-dependent subcortical route is engaged in unconscious fear processing but also suggest the existence of multiple routes for conscious fear processing.

关键词： neutral necessarily diameters

Outlier-resistant distributed fusion filtering for nonlinear discrete-time singular systems under a dynamic event-triggered scheme

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Frontiers of Information Technology & Electronic Engineering 2024年第2期25卷 237-249页

作者： Zhibin HU Jun HU Cai chen Hongjian LIU Xiaojian yi Department of Applied Mathematics Harbin University of Science and TechnologyHarbin150080China Heilongjiang Provincial Key Laboratory of Optimization Control and Intelligent Analysis for Complex Systems Harbin University of Science and TechnologyHarbin150080China School of Automation Harbin University of Science and TechnologyHarbin150080China School of Mathematics and Physics Anhui Polytechnic UniversityWuhu241000China School of Mechatronical Engineering Beijing Institute of TechnologyBeijing100081China Yangtze Delta Region Academy of Beijing Institute of Technology Jiaxing314003China Tangshan Research Institute Beijing Institute of TechnologyTangshan063099China

This paper investigates the problem of outlier-resistant distributed fusion filtering(DFF)for a class of multi-sensor nonlinear singular systems(MSNSSs)under a dynamic event-triggered scheme(DETS).To relieve the effect of measurement outliers in data transmission,a self-adaptive saturation function is ***,to further reduce the energy consumption of each sensor node and improve the efficiency of resource utilization,a DETS is adopted to regulate the frequency of data *** the addressed MSNSSs,our purpose is to construct the local outlier-resistant filter under the effects of the measurement outliers and the DETS;the local upper bound(UB)on the filtering error covariance(FEC)is derived by solving the difference equations and minimized by designing proper filter ***,according to the local filters and their UBs,a DFF algorithm is presented in terms of the inverse covariance intersection fusion *** such,the proposed DFF algorithm has the advantages of reducing the frequency of data transmission and the impact of measurement outliers,thereby improving the estimation ***,the uniform boundedness of the filtering error is discussed and a corresponding sufficient condition is ***,the validity of the developed algorithm is checked using a simulation example.

关键词： Distributed fusion filtering Multi-sensor nonlinear singular systems Dynamic event-triggered scheme Outlier-resistant filter Uniform boundedness

Churning loss characteristics of a wet three-phase high-speed reluctance motor

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第3期25卷 251-267页

作者： Zhenzhou ZHANG Mingzhu DAI chenchen ZHANG yi chen Bin MENG College of Mechanical Engineering Zhejiang University of TechnologyHangzhou 310023China

With the increasing requirements of electro-hydrostatic actuators(EHAs)for power,volume,and pressure,there is a growing tendency in the industry to combine the motor and pump to form a so-called'motor pump'to improve the *** this paper,a novel structure for a wet three-phase high-speed reluctance motor pump is proposed,which can further improve integration by removing the dynamic seal on the pump shaft,thereby avoiding the problems of dynamic seal wear and oil leakage and improving heat dissipation under high-speed working ***,after the motor is wetted,the churning loss caused by immersion of the rotor in the oil causes additional fluid resistance *** on fundamental fluid mechanics,an analytical model of the churning torque of a wet motor was *** verify the accuracy of the analytical model,a simulation model of churning loss was established based on computational fluid dynamics(CFD),and the churning torque and flow field state were ***,an experimental prototype was designed and manufactured,and a test bench for churning loss was *** oil churning torque was measured at different speeds and *** results from the analytical,simulation,and experimental models agreed *** experimental results validated the analytical model and CFD *** research provides a practical method for calculating the churning loss and serves as guidance for future optimization of churning loss reduction.

关键词： Motor pump Wet motor Churning loss Analytical model Computational fluid dynamics(CFD)