检索结果-南通市图书馆

Science China Chemistry 2024年第9期67卷 2975-2981页

作者： Xiaohong Li Shenfan Wang Xiangxiang fu Donghui Xing zeyuan fu Yuanfu Deng Huanfeng Jiang Liangbin Huang State Key Laboratory of Pulp and Paper Engineering School of Chemistry and Chemical EngineeringSouth China University of TechnologyGuangzhou 510640China

Herein,a nickel-catalyzed arylcyanation of unactivated alkenes via cyano group translocation with aryl boronic acids has been *** transformations provided a robust approach to constructing structurally diverse 1,n-dinitriles or 4-amino nitriles from easily prepared and commercially available starting *** cyano group translocation was achieved,involving the addition into the intramolecular C–N triple bond followed by the retro-Thorpe *** studies revealed that high temperature and CsHCO_(3) as the base were crucial for the cyano group translocation.

关键词： arylcyanation nickel catalysis cyano group translocation 1 n-dinitriles 4-amino nitriles

A Tutorial on Quantized Feedback Control

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2024年第1期11卷 5-17页

作者： Minyue fu IEEE the School of System Design and Intelligent Manufacturing Shenzhen Key Laboratory of Control Theory and Intelligent Systems and Centre for Control Science and TechnologySouthern University of Science and TechnologyShenzhen 518055China

In this tutorial paper, we explore the field of quantized feedback control, which has gained significant attention due to the growing prevalence of networked control systems. These systems require the transmission of feedback information, such as measurements and control signals, over digital networks, presenting novel challenges in estimation and control design. Our examination encompasses various topics, including the minimal information needed for effective feedback control, the design of quantizers, strategies for quantized control design and estimation,achieving consensus control with quantized data, and the pursuit of high-precision tracking using quantized measurements.

关键词： Consensus control high-precision control networked control quantized estimation quantized feedback control robust control

Dynamics of 2×2 matrix non-Hermitian quantum systems on Bloch sphere

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第4期76卷 66-71页

作者： Libin fu Graduate School of China Academy of Engineering Physics Beijing 100193China

By casting evolution to the Bloch sphere, the dynamics of 2 × 2 matrix non-Hermitian systems are investigated in detail. This investigation reveals that there are four kinds of dynamical modes for such systems. The different modes are classified by different kinds of fixed points, namely,the elliptic point, spiral point, critical node, and degenerate point. The Hermitian systems and the unbroken PT non-Hermitian cases belong to the category with elliptic points. The degenerate point just corresponds to the systems with exceptional point(EP). The topological properties of the fixed point are also discussed. It is interesting that the topological charge for the degenerate point is two, while the others are one.

关键词： non-Hermitian quantum system two-level system dynamics on the Bloch sphere PT-symmetry fixed points

Coupling Coordination Analysis of Cropland Intensification and Agroecosystem Services:Evidence from Loess Plateau in Shaanxi Province,China

在线全文

学校读者我要写书评

暂无评论

Chinese Geographical Science 2024年第3期34卷 401-419页

作者： fu Shaowu fu Mengyu QIU Menglong Center for Land Resource Research in Northwest China Shaanxi Normal UniversityXi’an 710119China

One of the greatest challenges in the agroecosystem is to improve cropland intensification while preserving agroecosystem *** many studies have investigated the effect of cropland intensification on agroecosystem service,the interactive coupling and coordination among these factors remain largely *** view of this,this study performed a case study of the Loess Plateau in Shaanxi Province,China and constructed comprehensive evaluation models to quantify the cropland intensification and agroecosystem service in this *** analysis and the coupling coordination degree model were used to evaluate the interactive relationship between cropland intensification and agroecosystem service,and statistical analysis and spatial autocorrelation were used to analyze the spatial characteristics and potential mechanism of the coupling *** show that both the cropland intensification and agroecosystem service in the study area were relatively low yet gradually increased from 2000 to *** service lag was identified as the dominant unbalanced development *** the supply capacity of agroecosystem services plays a key role in the balanced development of cropland in the Loess *** coupling coordination degree between cropland intensification and agroecosystem service ranges from basic coordination to serious ***,cropland intensification practices in the area should be optimized to enhance this coordination *** upward trend was also observed in the coupling coordination degree from2000 to *** withdrawal of marginal cropland in the Grain for Green program is one of the most important reasons for this trend,especially for the northern *** 83.6%of the high-high clusters are concentrated in the southern region of the Loess Plateau,whereas 70.5%of the low-low clusters are distributed in the northern *** clustering characteristics are mainly attributed to the environmental

关键词： cropland intensification agroecosystem services balance analysis coupling coordination degree Loess Plateau,China

Floating Waste Discovery by Request via Object-Centric Learning

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第7期80卷 1407-1424页

作者： Bingfei fu School of Computer Science Fudan UniversityShanghai200438China

Discovering floating wastes,especially bottles on water,is a crucial research problem in environmental ***,real-world applications often face challenges such as interference from irrelevant objects and the high cost associated with data ***,devising algorithms capable of accurately localizing specific objects within a scene in scenarios where annotated data is limited remains a formidable *** solve this problem,this paper proposes an object discovery by request problem setting and a corresponding algorithmic *** proposed problem setting aims to identify specified objects in scenes,and the associated algorithmic framework comprises pseudo data generation and object discovery by request ***-data generation generates images resembling natural scenes through various data augmentation rules,using a small number of object samples and scene *** network structure of object discovery by request utilizes the pre-trained Vision Transformer(ViT)model as the backbone,employs object-centric methods to learn the latent representations of foreground objects,and applies patch-level reconstruction constraints to the *** the validation phase,we use the generated pseudo datasets as training sets and evaluate the performance of our model on the original test *** have proved that our method achieves state-of-the-art performance on Unmanned Aerial Vehicles-Bottle Detection(UAV-BD)dataset and self-constructed dataset Bottle,especially in multi-object scenarios.

关键词： Unsupervised object discovery object-centric learning pseudo data generation real-world object discovery by request

LMR-CBT: learning modality-fused representations with CB-Transformer for multimodal emotion recognition from unaligned multimodal sequences

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Computer Science 2024年第4期18卷 39-47页

作者： Ziwang fu Feng LIU Qing XU Xiangling fu Jiayin QI School of Computer Science(National Pilot Software Engineering School) Beijing University of Posts and TelecommunicationsBeijing 100876China Key Laboratory of Trustworthy Distributed Computing and Service(BUPT) Beijing 100876China Shanghai International School of Chief Technology Officer East China Normal UniversityShanghai 200062China School of Computer Science and Technology East China Normal UniversityShanghai 200062China School of Cyberspace Security Guangzhou UniversityGuangdong 510006China

Learning modality-fused representations and processing unaligned multimodal sequences are meaningful and challenging in multimodal emotion *** approaches use directional pairwise attention or a message hub to fuse language,visual,and audio ***,these fusion methods are often quadratic in complexity with respect to the modal sequence length,bring redundant information and are not *** this paper,we propose an efficient neural network to learn modality-fused representations with CB-Transformer(LMR-CBT)for multimodal emotion recognition from unaligned multi-modal ***,we first perform feature extraction for the three modalities respectively to obtain the local structure of the ***,we design an innovative asymmetric transformer with cross-modal blocks(CB-Transformer)that enables complementary learning of different modalities,mainly divided into local temporal learning,cross-modal feature fusion and global self-attention *** addition,we splice the fused features with the original features to classify the emotions of the ***,we conduct word-aligned and unaligned experiments on three challenging datasets,IEMOCAP,CMU-MOSI,and *** experimental results show the superiority and efficiency of our proposed method in both *** with the mainstream methods,our approach reaches the state-of-the-art with a minimum number of parameters.

关键词： modality-fused representations cross-model blocks multimodal emotion recognition unaligned multimodal sequences computational affection

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

园艺植物性别决定的表观遗传机制研究进展

园艺学报 2022年第7期49卷 1602-1610页

作者：杨琳琳黄云彤付泽元徐启江东北林业大学生命科学学院东北盐碱植被恢复与重建教育部重点实验室哈尔滨150040 右江民族医学院医学检验学院广西百色533000

在被子植物中,花分为两性花和单性花两种类型,而单性花又有雌雄异花同株和雌雄异株之分。在单性花性别分化过程中,性别决定涉及多种调节机制,其中表观遗传机制发挥重要的作用。本文中综述了DNA甲基化、组蛋白修饰以及microRNA等表观遗... 详细信息

在被子植物中,花分为两性花和单性花两种类型,而单性花又有雌雄异花同株和雌雄异株之分。在单性花性别分化过程中,性别决定涉及多种调节机制,其中表观遗传机制发挥重要的作用。本文中综述了DNA甲基化、组蛋白修饰以及microRNA等表观遗传机制在园艺植物性别决定方面的作用以及表观调控通过调节植物激素影响植物性别和花器官发育的研究进展,并对今后相关研究进行展望。

关键词：园艺植物单性花性别决定表观遗传

New speckle pattern interferometry for precise in situ deformation measurements

在线全文

学校读者我要写书评

暂无评论

Chinese Optics Letters 2024年第1期22卷 34-40页

作者：章如月 Yu fu 缪泓 CAS Key Laboratory of Mechanical Behavior and Design of Materials Department of Modern MechanicsUniversity of Science and Technology of ChinaHefei 230027China Shenzhen Key Laboratory of Intelligent Optical Measurement and Detection College of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen 518060China

A new electronic speckle pattern interferometry method is proposed to realize in situ deformation *** feature of the method is the combination of a high-speed camera and multiple laser Doppler vibrometers(LDVs)for synchronous *** high-speed camera is used to record and select effective interferograms,while the LDVs are used to measure the rigid body displacement caused by vibrations.A series of effective interferograms with known shifted phase values are obtained to calculate the deformation *** experimental results show that the method performs well in measuring static and dynamic deformations with high accuracy in vibrating environments.

关键词： speckle pattern interferometry laser Doppler vibrometers in situ deformation measurements

Small Cycles Property of Some Cremer Rational Maps and Polynomials

在线全文

学校读者我要写书评

暂无评论

Chinese Annals of Mathematics,Series B 2024年第1期45卷 123-136页

作者： Rong fu Ji ZHOU Faculty of Science Yibin UniversityYibin 644000SichuanChina Department of Mathematical Sciences Sichuan Normal UniversityChengdu 610066China

This paper concerns the linearization problem on rational maps of degree d≥2 and polynomials of degree d>2 from the perspective of *** authors introduce a set l_(∞) of irrational numbers and show that if α∈l_(∞),then any rational map is not linearizable and has infinitely many cycles in every neighborhood of the fixed point with multiplier λ=e^(2πiα),Adding more constraints to cubic polynomials,they discuss the above problems by polynomial-like *** the family of polynomials,with the help of Yoccoz's method,they obtain its maximum dimension of the set in which the polynomials are non-linearizable.

关键词： Irrationally indifferent fixed point Linearization problem Small cycles property

A stochastic gradient-based two-step sparse identification algorithm for multivariate ARX systems

在线全文

学校读者我要写书评

暂无评论

Control Theory and Technology 2024年第2期22卷 213-221页

作者： Yanxin fu Wenxiao Zhao Key Laboratory of Systems and Control Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing100190China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing100049China

We consider the sparse identification of multivariate ARX systems, i.e., to recover the zero elements of the unknown parameter matrix. We propose a two-step algorithm, where in the first step the stochastic gradient (SG) algorithm is applied to obtain initial estimates of the unknown parameter matrix and in the second step an optimization criterion is introduced for the sparse identification of multivariate ARX systems. Under mild conditions, we prove that by minimizing the criterion function, the zero elements of the unknown parameter matrix can be recovered with a finite number of observations. The performance of the algorithm is testified through a simulation example.

关键词： ARX system Stochastic gradient algorithm Sparse identification Support recovery Parameter estimation Strong consistency