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Spin effect on redox acceleration and regioselectivity in Fe-catalyzed alkyne hydrosilylation

National Science Review 2024年第2期11卷 155-167页

作者： Peng He Meng-Yang Hu Jin-Hong Li Tian-Zhang Qiao Yi-Lin Lu shou-Fei Zhu Frontiers Science Center for New Organic Matter State Key Laboratory and Institute of Elemento-Organic Chemistry Nankai University

Iron catalysts are ideal transition metal catalysts because of the Earths abundant, cheap, biocompatible features of iron salts. Iron catalysts often have unique open-shell structures that easily undergo spin crossover in chemical transformations, a feature rarely found in noble metal catalysts. Unfortunately, little is known currently about how the open-shell structure and spin crossover affect the reactivity and selectivity of iron catalysts, which makes the development of iron catalysts a low efficient trial-and-error program. In this paper, a combination of experiments and theoretical calculations revealed that the iron-catalyzed hydrosilylation of alkynes is typical spin-crossover catalysis. Deep insight into the electronic structures of a set of well-defined open-shell active formal Fe(0) catalysts revealed that the spin-delocalization between the iron center and the 1,10-phenanthroline ligand effectively regulates the iron center's spin and oxidation state to meet the opposite electrostatic requirements of oxidative addition and reductive elimination, respectively,and the spin crossover is essential for this electron transfer process. The triplet transition state was essential for achieving high regioselectivity through tuning the nonbonding interactions. These findings provide an important reference for understanding the effect of catalyst spin state on reaction. It is inspiring for the development of iron catalysts and other Earth-abundant metal catalysts, especially from the point of view of ligand development.

关键词： spin effect spin-delocalization spin crossover iron-catalysis alkyne hydrosilylation

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Wave interaction for a generalized higher-dimensional Boussinesq equation describing the nonlinear Rossby waves

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Journal of Oceanology and Limnology 2024年第5期42卷 1415-1424页

作者： Rong SU Penghao JI Xiaojun yin College of Science Inner Mongolia Agricultural UniversityHohhot 010018China

Based on an algebraically Rossby solitary waves evolution model,namely an extended(2+1)-dimensional Boussinesq equation,we firstly introduced a special transformation and utilized the Hirota method,which enable us to obtain multi-complexiton solutions and explore the interaction among the *** wave functions are then employed to infer the influence of background flow on the propagation of Rossby waves,as well as the characteristics of propagation in multi-wave running ***,we generated stereogram drawings and projection figures to visually represent these *** dynamical behavior of these solutions is thoroughly examined through analytical and graphical ***,we investigated the influence of the generalized beta effect and the Coriolis parameter on the evolution of Rossby waves.

关键词： Rossby wave Boussinesq equation Complexiton solution Breather solution

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Stereoselective Synthesis of 2-Deoxy-α-N-Glycosides from Glycals with 1,4,2-Dioxazol-5-ones

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Chinese Journal of Chemistry 2024年第18期42卷 2147-2152页

作者： Zhenpeng Shen Guoyin yin Yangyang Li The Institute for Advanced Studies Wuhan UniversityWuhanHubei 430072China

The synthesis of N-glycosides has received significant attention due to their crucial role in carbohydrate *** considerable advancements developed in the construction of N-glycosides,methods for the stereoselective construction of 2-deoxy-α-N-glycosides are still ***,we disclosed a nickel-catalyzed hydroamination of glycals under mild *** transformation could allow for the stereoselective synthesis of an array of 2-deoxy-α-N-glycosides with excellentα-***-catalyzed glycosylation reactions,particularly those involving anomeric C(sp")-metal bond formation,have proven to be an effective and stereoselective strategy for producing various ***,with highlight of the application of this reaction,y-sugar amino acidderivatives weresynthesized.

关键词： 2-Deoxy-α-N-glycosides Nickel catalysis Stereoselectivity Glycals Hydroamination Amides Glycosylation Alkenes ComprehensiveSummary

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Learning to optimize:A tutorial for continuous and mixed-integer optimization

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Science China Mathematics 2024年第6期67卷 1191-1262页

作者： Xiaohan Chen Jialin Liu Wotao yin Decision Intelligence Lab Alibaba DAMO AcademyBellevueWA98004USA

Learning to optimize(L2O)stands at the intersection of traditional optimization and machine learning,utilizing the capabilities of machine learning to enhance conventional optimization *** real-world optimization problems frequently share common structures,L2O provides a tool to exploit these structures for better or faster *** tutorial dives deep into L2O techniques,introducing how to accelerate optimization algorithms,promptly estimate the solutions,or even reshape the optimization problem itself,making it more adaptive to real-world *** considering the prerequisites for successful applications of L2O and the structure of the optimization problems at hand,this tutorial provides a comprehensive guide for practitioners and researchers alike.

关键词： AI for mathematics(AI4Math) learning to optimize algorithm unrolling plug-and-play methods differentiable programming machine learning for combinatorial optimization(ML4CO)

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Low-Brightness Object Recognition Based on Deep Learning

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Computers, Materials & Continua 2024年第5期79卷 1757-1773页

作者： Shu-yin Chiang Ting-Yu Lin Department of Information and Telecommunications Engineering Ming Chuan UniversityTaoyuan City333Taiwan

This research focuses on addressing the challenges associated with image detection in low-light environments,particularly by applying artificial intelligence techniques to machine vision and object recognition *** primary goal is to tackle issues related to recognizing objects with low brightness *** this study,the Intel RealSense Lidar Camera L515 is used to simultaneously capture color information and 16-bit depth information *** detection scenarios are categorized into normal brightness and low brightness *** the system determines a normal brightness environment,normal brightness images are recognized using deep learning *** low-brightness situations,three methods are proposed for *** first method is the SegmentationwithDepth image(SD)methodwhich involves segmenting the depth image,creating amask from the segmented depth image,mapping the obtained mask onto the true color(RGB)image to obtain a backgroundreduced RGB image,and recognizing the segmented *** second method is theHDVmethod(hue,depth,value)which combines RGB images converted to HSV images(hue,saturation,value)with depth images D to form HDV images for *** third method is the HSD(hue,saturation,depth)method which similarly combines RGB images converted to HSV images with depth images D to form HSD images for *** experimental results,in normal brightness environments,the average recognition rate obtained using image recognition methods is 91%.For low-brightness environments,using the SD method with original images for training and segmented images for recognition achieves an average recognition rate of over 82%.TheHDVmethod achieves an average recognition rate of over 70%,while the HSD method achieves an average recognition rate of over 84%.The HSD method allows for a quick and convenient low-light object recognition *** research outcome can be applied to nighttime surveillance systems or nighttime road safety systems

关键词： Low-brightness depth image image segmentation image recognition HDV HSD

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Alternative Method of Constructing Granular Neural Networks

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Computers, Materials & Continua 2024年第4期79卷 623-650页

作者： Yushan yin Witold Pedrycz Zhiwu Li School of Electro-Mechanical Engineering Xidian UniversityXi’an710071China Department of Electrical and Computer Engineering University of AlbertaEdmontonABT6R 2V4Canada

Utilizing granular computing to enhance artificial neural network architecture, a newtype of network emerges—thegranular neural network (GNN). GNNs offer distinct advantages over their traditional counterparts: The ability toprocess both numerical and granular data, leading to improved interpretability. This paper proposes a novel designmethod for constructing GNNs, drawing inspiration from existing interval-valued neural networks built uponNNNs. However, unlike the proposed algorithm in this work, which employs interval values or triangular fuzzynumbers for connections, existing methods rely on a pre-defined numerical network. This new method utilizesa uniform distribution of information granularity to granulate connections with unknown parameters, resultingin independent GNN structures. To quantify the granularity output of the network, the product of two commonperformance indices is adopted: The coverage of numerical data and the specificity of information *** this combined performance index helps determine the optimal parameters for the network. Finally,the paper presents the complete model construction and validates its feasibility through experiments on datasetsfrom the UCIMachine Learning Repository. The results demonstrate the proposed algorithm’s effectiveness andpromising performance.

关键词： Granular neural network granular connection interval analysis triangular fuzzy numbers particle swarm optimization(PSO)

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VKFQ:A Verifiable Keyword Frequency Query Framework with Local Differential Privacy in Blockchain

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Computers, Materials & Continua 2024年第3期78卷 4205-4223页

作者： Youlin Ji Bo yin Ke Gu School of Computer and Communication Engineering Changsha University of Science and TechnologyChangsha410114China

With its untameable and traceable properties,blockchain technology has been widely used in the field of data *** to preserve individual privacy while enabling efficient data queries is one of the primary issues with secure data *** this paper,we study verifiable keyword frequency(KF)queries with local differential privacy in *** the numerical and the keyword attributes are present in data objects;the latter are sensitive and require privacy ***,prior studies in blockchain have the problem of trilemma in privacy protection and are unable to handle KF *** propose an efficient framework that protects data owners’privacy on keyword attributes while enabling quick and verifiable query processing for KF *** framework computes an estimate of a keyword’s frequency and is efficient in query time and verification object(VO)size.A utility-optimized local differential privacy technique is used for privacy *** data owner adds noise locally into data based on local differential privacy so that the attacker cannot infer the owner of the keywords while keeping the difference in the probability distribution of the KF within the privacy *** propose the VB-cm tree as the authenticated data structure(ADS).The VB-cm tree combines the Verkle tree and the Count-Min sketch(CM-sketch)to lower the VO size and query *** VB-cm tree uses the vector commitment to verify the query *** fixed-size CM-sketch,which summarizes the frequency of multiple keywords,is used to estimate the KF via hashing *** conduct an extensive evaluation of the proposed *** experimental results show that compared to theMerkle B+tree,the query time is reduced by 52.38%,and the VO size is reduced by more than one order of magnitude.

关键词： Security data sharing blockchain data query privacy protection

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Trade-offs between chemical resistance to herbivory and responses to abiotic stresses in invasive plants

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Journal of Plant Ecology 2024年第2期17卷 18-23页

作者： Lifeng Zhou Wandong yin Jianqing Ding State Key Laboratory of Crop Stress Adaptation and Improvement School of Life SciencesHenan UniversityKaifeng 475004China

INTRODUCTION Plants change their traits to respond to shifting environments,enabling them to defend against biotic stresses such as herbivorous insects,and/or tolerate abiotic stresses,such as extreme climate(Callaway et al.2022;Zhang et al.2018,2022).There are often costs when plants produce secondary chemicals to adapt to varying biotic or abiotic environments(Abdala-Roberts et al.2016).

关键词： traits ). environments

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Rigidity of non-renormalizable Newton maps

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Science China Mathematics 2024年第4期67卷 855-872页

作者： Pascale Roesch Yongcheng yin Jinsong Zeng Institut de Mathématiques de Toulouse Universite Paul SabatierToulouse 31062France School of Mathematical Sciences Zhejiang UniversityHangzhou 310027China College of Mathematics and Statistics Shenzhen UniversityShenzhen 518061China

Non-renormalizable Newton maps are *** precisely,we prove that their Julia sets carry no invariant line fields and that a topological conjugacy between them is equivalent to a quasiconformal conjugacy.

关键词： Newton map non-renormalizable rigidity invariant line field

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In situ protonation in a locally flexible porous coordination polymer for enhancing proton-carrier loading and proton conductivity

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Science China Chemistry 2024年第10期67卷 3432-3437页

作者： Xianzhe Wei Jincheng Liu Yan Su Weitao Wang Guixiang Wang gen Zhang Ping Wang Cheng Gu State Key Laboratory of Luminescent Materials and Devices Institute of Polymer Optoelectronic Materials and DevicesSouth China University of TechnologyGuangzhou 510640China College of Polymer Science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu 610065China Key Laboratory for Soft Chemistry and Functional Materials of Ministry of Education School of Chemistry and Chemical EngineeringNanjing University of Science and TechnologyNanjing 210094China

Designing efficient proton-conductive materials is crucial in fuel ***,it remains a substantial challenge because of the issues in proton mobility,proton-carrier amount,and orientation of proton host ***,we report an in-situ protonation strategy to produce a locally flexible porous coordination polymer(PCP)to enhance the proton-carrier loading and proton *** local dipole flipping of the ligand allows effective proton exchange with low activation energy,promoting interpore proton transport through the pore apertures and pore *** protonation induces substantial charges to the frameworks and enhances the interaction with proton carriers,thereby increasing the loading of the proton *** this design strategy,the resulting PCP exhibits enhanced phosphoric acid loading and extraordinary proton conductivities under both aqueous and anhydrous conditions compared to its isoreticular analog that features rigidity without proton-exchange *** work provides a new avenue for designing proton-conductive materials that combine structural dynamics with performance merits.

关键词： porous coordination polymers in-situ protonation local flexibility proton-exchange mechanism proton conduction

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