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Vanadium(V) Complexes Containing Unsymmetrical N-Heterocyclic Carbene Ligands: Highly Efficient Synthesis and Catalytic Behavior towards Ethylene/Propylene Copolymerization

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Chinese Journal of Polymer Science 2024年第1期42卷 32-41,I0006页

作者： yi-Cong Wang Hui Zhat Pei-yi Cheng Shu Zhang Xiang-Wei Liu yi-Xian wu State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBejing 100029China

The highly efficient method has been developed for the synthesis of NHC·VOCl_(3) containing symmetrical or unsymmetrical Nheterocyclic carbene(NHC) ligands by the transmetallation reaction of NHC·AgCl with VOCl_(3).The total isolated yield of VOCl_(3)[1,3-(2,4,6-Me_(3)C_(6)H_(2))_(2)(NCH=)_(2)C:](V4') reached 86% by transmetallation reaction,which is much higher than that(48%) by direct coordination *** methodology has also been used to synthesize the novel vanadium complexes containing unsymmetrical NHC ligands of VOCl_(3)[PhCH_(2)NCH=CHNR)C:](V5',R=2,4,6-Me_(3)C_(6)H_(2);V6',R=2,4-Me_(2)-6-Ph-C_(6)H_(2);V7',R=2,6-^(i)Pr_(2)-C_(6)H_(3)) with high yield,which could not be obtained by direct coordination *** catalytic activity and copolymerization ability would be improved by introducing unsymmetrical NHC ligands due to their less steric bulky *** vanadium complex V5' containing unsymmetrical NHC ligand exhibits higher catalytic activity(3.7×10^(5)g_(copolymer)·mol^(-1) of V·h^(-1)) than that of V4' containing symmetrical NHC ***,the higher propylene incorporation ratio(45.6 mol%) in the copolymers of ethylene with propylene could be obtained by using V5' than that(39.9%) by using V4'.The results would provide a highly efficient strategy for the synthesis of early transition metal complexes containing versitile NHC ligands,affording the catalyst with both high catalytic activity and copolymerization ability for the synthesis of high performance polyolefin elastomers.

关键词： Vanadium complex N-heterocyclic carbene ligand Transmetallation reaction Copolymerization of ethylene with propylene

Weighted Probability Density Estimator with Updated Bandwidths

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Journal of Systems Science & Complexity 2024年第2期37卷 886-906页

作者： wu yi YU Wei WANG Xuejun PRAKASA RAO B L S School of Big Data and Artificial Intelligence Chizhou UniversityChizhou 247000China School of Big Data and Statistics Anhui UniversityHefei 230601China CR Rao Advanced Institute of Mathematics Statistics and Computer ScienceHyderabad 500046India

In this paper,the authors study a class of weighted version of probability density *** is shown that the weighted estimator contains some existing estimators of probability density,no matter they are recursive or *** statistical results including weak consistency,strong consistency,rate of strong consistency,and asymptotic normality are established under some mild ***,the random weighted estimator is also *** numerical simulations and a real data analysis are presented to study the numerical performances of the estimators.

关键词： Asymptotic normality consistency numerical simulation probability density real data analysis updated bandwidths weighted estimator

An Adaptive Local Grid Nesting-based Genetic Algorithm for Multi-earth Observation Satellites' Area Target Observation

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Journal of Systems Science and Systems Engineering 2024年第2期33卷 232-258页

作者： Ligang Xing Wei Xia Xiaoxuan Hu Waiming Zhu yi wu School of Management Hefei University of TechnologyHefei 230009China Key Laboratory of Process Optimization and Inteligent Decision-making Ministry of EducationHefei 230009China Intelligent Interconnected Systems Laboratory of Anhui Province Hefei 230009China

The Scheduling of the Multi-EOSs Area Target Observation(SMEATO)is an EOS resource schedul-ing problem highly coupled with computational *** advances in EOS technology and the ex-pansion of wide-area remote sensing applications have increased the practical significance of *** this paper,an adaptive local grid nesting-based genetic algorithm(ALGN-GA)is proposed for developing SMEATO ***,a local grid nesting(LGN)strategy is designed to discretize the target area into parts,so as to avoid the explosive growth of calculations.A genetic algorithm(GA)framework is then used to share reserve information for the population during iterative evolution,which can generate high-quality solutions with low computational *** this basis,an adaptive technique is introduced to determine whether a local region requires nesting and whether the grid scale is *** effectiveness of the proposed model is assessed experimentally with nine randomly generated tests at different *** results show that the ALGN-GA offers advantages over several conventional algorithms in 88.9%of instances,especially in large-scale *** fully demonstrate the high efficiency and stability of the ALGN-GA.

关键词： Multi-EOSs scheduling area target observation adaptive genetic algorithm local grid nesting

Investigations of the mechanical response of dummy HTPB propellant grain under ultrahigh acceleration overload conditions using onboard flight-test measurements

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Defence Technology（防务技术） 2024年第2期32卷 473-484页

作者： yiming Zhang Ningfei Wang Weihua Ma Ran Wang Long Bai yi wu School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China Beijing System Design Institute of Electro-mechanic Engineering Beijing 100854China Xi'an Changfeng Research Institute of Mechanism and Electricity Xi'an 710065China

In this paper,to study the mechanical responses of a solid propellant subjected to ultrahigh acceleration overload during the gun-launch process,specifically designed projectile flight tests with an onboard measurement system were *** projectiles containing dummy HTPB propellant grains were successfully recovered after the flight tests with an ultrahigh acceleration overload value of 8100 *** onboard-measured time-resolved axial displacement,contact stress and overload values were successfully obtained and *** compression tests of the dummy HTPB propellant used in the gunlaunched tests were carried out at low and intermediate strain rates to characterize the propellant's dynamic properties.A linear viscoelastic constitutive model was employed and applied in finite-element simulations of the projectile-launching *** the launch process,the dummy propellant grain exhibited large deformation due to the high acceleration overload,possibly leading to friction between the motor case and propellant *** calculated contact stress showed good agreement with the experimental results,though discrepancies in the overall displacement of the dummy propellant grain were *** dynamic mechanical response process of the dummy propellant grain was analysed in *** results can be used to estimate the structural integrity of the analysed dummy propellant grain during the gun-launch process.

关键词： Gun-launched flight test Dummy HTPB propellant Onboard measurements Utrahigh overload Mechanical response

To improve robustness of mechanical properties of semi-solid cast A356 alloy using taguchi design method

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China Foundry 2024年第2期21卷 175-184页

作者： yi-wu Xu Hong-yi Zhan Wei Tong Jin-ping Li Le-peng Zhang De-jiang Li Xiao-qin Zeng School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China China Science Lab General Motors Global Research&DevelopmentShanghai 201206China General Motors(China)Investment Co. Ltd.Shanghai 201206China China International Intellectech Corporation(CIIC) Beijing 100004China

Mechanical properties of semi-solid casting are dependent on multiple processing parameters,and improper processing parameters will not only reduce mean data but also increase *** present study investigated the impact of parameters in slurry preparation and heat treatment on the yield strength and ductility of T6 heat-treated A356 Al-Si alloy using rapid slurry forming(RSF)semi-solid *** focus was primarily on the robustness of mechanical properties based on Taguchi design *** analyzing signal-to-noise ratio and minimum value calculated from-3S,the optimum slurry preparation parameters and heat treatment parameters were determined to be no quench,enthalpy exchange material(EEM)temperature of 140℃,EEM-to-melt ratio of 6mass%,stirring time of 18 s,solution heat treated at 520℃ for 2 h,and ageing heat treated at 190℃ for 6 *** a small batch validation,the-3S yield strength and-3S elongation reach 256.1 MPa and 5.03% respectively,showing a satisfactory *** hardness and microstructure of heat-treated samples with the best and worst properties were characterized to gain insight into the underlying mechanisms affecting the mean value and variations of mechanical properties.

关键词： semi-solid casting taguchi design method signal-to-noise ratio mechanical property microstructure

Numerical Simulation Study of Oil-Water Emulsion Separation in an Ultrasonic Field:Effect of Coupling between Acoustic and Flow Field Parameters

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China Petroleum Processing & Petrochemical Technology 2024年第1期26卷 116-125页

作者： Wang Heping Lin yinchao Li Yanggui Zhang Xiaohang wu yi Key Laboratory of Engineering Mathematics and Advanced Computing of Nanchang Institute of Technology School of SciencesNanchang Institute of TechnologyNanchang 330099People’s Republic of China Dongguan Key Laboratory of Kunpeng Computing School of Computer ScienceGuangdong University of Science&TechnologyDongguan 523083China State Key Laboratory of Plateau Ecology and Agriculture Qinghai UniversityXining 810016China

In this study,the separation and coalescence of oil-in-water emulsions are explored in an ultrasonic field using the lattice Boltzmann *** simulating the propagation of ultrasonic waves,this study focuses on examining the effects of acoustic wave frequency,the ratio of oil to water components,and the aspect ratio of the boundary on the emulsification and separation processes of oil-water *** following conclusions are drawn.①Frequency affects the speed of oil droplet separation,leading to an increase in droplet size over *** droplets are found near the source,while smaller droplets are distributed throughout the wave web.②As the boundary aspect ratio increases,the emulsification efficiency of the droplets weakens,and the system takes longer to stabilize.③Emulsions with a higher component of oil can better resist acoustic waves.④At the same acoustic frequency,longer wavelength ultrasonic fields promote the formation of uniformly distributed,smaller oil droplets,which is beneficial to the storage of *** numerical simulation results offer insights for optimizing conditions for oil-in-water separation and serve as a numerical reference for the study of oil-in-water emulsion separation in ultrasonic environments.

关键词： lattice Boltzmann method phase separation ultrasound field

Hybridization-mediated quasiparticle and phonon dynamics in single crystal cerium films

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Science China(Physics,Mechanics & Astronomy) 2024年第4期67卷 146-153页

作者： Yunhe Pei yi wu Kai Hu Zhengxing Wei yiFeng Yang Yang Liu Jingbo Qi State Key Laboratory of Electronic Thin Films and Integrated Devices University of Electronic Science and Technology of ChinaChengdu 611731China Center for Correlated Matter and Department of Physics Zhejiang UniversityHangzhou 310058China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Songshan Lake Materials Laboratory Dongguan 523808China Collaborative Innovation Center of Advanced Microstructures Nanjing UniversityNanjing 210093China

We report the ultrafast optical pump-probe spectroscopy measurements on the single-crystal cerium *** experimental results of temperature-dependent quasiparticle dynamics reveal development of the hybridization between localized f moments and conduction electrons,i.e.,evolving from fluctuating hybridization to collective *** phonon renormalization is discovered to appear at the emerging temperature(T^(+))of fluctuating hybridization apart from its known presence at the coherent temperature(T^(*)),and can hardly be explained by the mean-field *** quasiparticle relaxation at high temperatures indicates coexistence of nonthermal electron-electron scattering and inelastic Kondo scattering,while its behavior at low temperatures suggests onset ofαphase in theγ-phase dominated *** also extract the indirect gap below T^(*),representing the appearance of collective *** findings provide novel information about the hybridization and phase evolution in the heavy fermion systems.

关键词： cerium quasiparticle dynamics hybridization phonon renormalization

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A transcriptional cascade mediated by two APETALA2 family members orchestrates carotenoid biosynthesis in tomato

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Journal of Integrative Plant Biology 2024年第6期66卷 1227-1241页

作者： Xiaoqing He Kaidong Liu yi wu Weijie Xu Ruochen Wang Julien Pirrello Mondher Bouzayen Mengbo wu Mingchun Liu Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education College of Life SciencesSichuan UniversityChengdu 610065China Life Science and Technology School Lingnan Normal UniversityZhanjiang 524048China Laboratoire de Recherche en Sciences Vegetales—Genomique et Biotechnologie des Fruits—UMR5546 Universite de ToulouseCNRSUPSToulouse-INPToulouse 31013France

Carotenoids are important nutrients for human health that must be obtained from plants since they cannot be biosynthesized by the human *** the regulatory mechanism of carotenoid metabolism in plants represents the first step toward manipulating carotenoid contents in plants by molecular design *** this study,we determined that SlAP2c,an APETALA2(AP2)family member,acts as a transcriptional repressor to regulate carotenoid biosynthesis in tomato(Solanum lycopersicum).Knockout of SlAP2c in both the“Micro Tom”and“Ailsa Craig”backgrounds resulted in greater lycopene accumulation,whereas overexpression of this gene led to orange-ripe fruit with significantly lower lycopene contents than the wild *** established that SlAP2c represses the expression of genes involved in lycopene biosynthesis by directly binding to the cis-elements in their ***,SlAP2c relies on its EAR motif to recruit the co-repressors TOPLESS(TPL)2/4 and forms a complex with histone deacetylase(had)1/3,thereby reducing the histone acetylation levels of lycopene biosynthesis ***,SlAP2a,a homolog of SlAP2c,acts upstream of SlAP2c and alleviates the SlAP2c-induced repression of lycopene biosynthesis genes by inhibiting SlAP2c transcription during fruit ***,we identified a transcriptional cascade mediated by AP2 family members that regulates lycopene biosynthesis during fruit ripening in tomato,laying the foundation for the manipulation of carotenoid metabolism in plants.

关键词： APETALA2 family members carotenoid biosynthesis tomato transcriptional cascade

Nanotechnology’s frontier in combatting infectious and inflammatory diseases:prevention and treatment

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Signal Transduction and Targeted Therapy 2024年第3期9卷 998-1047页

作者： Yujing Huang Xiaohan Guo yi wu Xingyu Chen Lixiang Feng Na Xie Guobo Shen Department of Biotherapy Cancer Center and State Key Laboratory of BiotherapyWest China Hospitaland West China School of Basic Medical Sciences and Forensic MedicineSichuan Universityand Collaborative Innovation Center for BiotherapyChengdu 610041China

Inflammation-associated diseases encompass a range of infectious diseases and non-infectious inflammatory diseases,which continuously pose one of the most serious threats to human health,attributed to factors such as the emergence of new pathogens,increasing drug resistance,changes in living environments and lifestyles,and the aging *** rapid advancements in mechanistic research and drug development for these diseases,current treatments often have limited efficacy and notable side effects,necessitating the development of more effective and targeted anti-inflammatory *** recent years,the rapid development of nanotechnology has provided crucial technological support for the prevention,treatment,and detection of inflammation-associated *** types of nanoparticles(NPs)play significant roles,serving as vaccine vehicles to enhance immunogenicity and as drug carriers to improve targeting and *** can also directly combat pathogens and *** addition,nanotechnology has facilitated the development of biosensors for pathogen detection and imaging techniques for inflammatory *** review categorizes and characterizes different types of NPs,summarizes their applications in the prevention,treatment,and detection of infectious and inflammatory *** also discusses the challenges associated with clinical translation in this field and explores the latest developments and *** conclusion,nanotechnology opens up new possibilities for the comprehensive management of infectious and inflammatory diseases.

关键词： prevention inflammatory treatment