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Rational design of AgGaS/z.S/z.S quantum dots with a near-unity photoluminescence quantum yield via double shelling scheme

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Journal of Materials Science & Technology 2024年第2期169卷 235-242页

作者： H.X.Lu H.Liu z.z.fu Y.Y.Chen H.Q.Dai z.Hu W.L.z.ang R.Q.Guo Institute for Electric Light Sources School of Information Science and TechnologyFudan UniversityShanghai 200433China Institute of future Lighting Academy for Engineering and TechnologyFudan UniversityShanghai 200433China Yiwu Research Institute of fudan University YiwuZhejiang 322000China z.ongshan-fudan Joint Innovation Center Zhongshan 528437China

In this study,a two-step method was used to synthesiz. highly luminescent AgGaS/z.S/z.S quantum dots(QDs).In the first step,an inner z.S shell was formed via a one-pot method,which resulted in a smaller lattice mismatch between the AgGaS core and the outer z.S shell,thereby facilitating the formation of a thick outer *** the two-step shelling process,the synthesiz.d AgGaS/z.S/z.S QDs showed an excellent photoluminescence quantum yield(PLQY)of 96.4%with a peak wavelength of 508 nm,repre-senting the highest PLQY reported thus far for AgGaS ***,the effect of halogen ions in z. precursors on the shelling process was *** was proposed that the capacity of halogen ions to coordinate with the QDs influenced the balance between z. cation diffusion and z.S shelling ***,the z.S shelling reaction was dominant when z.Cl_(2)was employed,while z. cation diffusion was the dominant process under the I^(−)-rich *** work provides insights into the interfacial restructuring during the z.S shelling and offers a clear map for the tailored synthesis of core/shell QDs.

关键词： AgGaS Quantum dots Photoluminescence Core/shell Alloyed core/shell interface

A Tutorial on Quantiz.d Feedback Control

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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 quantiz.d 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 quantiz.rs, strategies for quantiz.d control design and estimation,achieving consensus control with quantiz.d data, and the pursuit of high-precision tracking using quantiz.d measurements.

关键词： Consensus control high-precision control networked control quantiz.d estimation quantiz.d feedback control robust control

Numerical Study of Flow Features Around Submerged Circular and Square Piles at Flat and Scoured Beds Using OpenFOAM

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Journal of Ocean University of China 2024年第4期23卷 897-914页

作者： WANG Chaolin WU Guoxiang WANG Dianhe DU Shengtao z.ANG z.iyong JIN Heng z.U David z. LIANG Bingchen Donghai Academy School of Civil&Environmental Engineering and Geography ScienceNingbo UniversityNingbo 315211China Key Laboratory of Estuary and Coast of z.ejiang Province and Zhejiang Institute of Hydraulics and EstuaryHangzhou 310020China Shandong Provincial Key Laboratory of Ocean Engineering and College of EngineeringOcean University of ChinaQingdao 266100China Shandong Water Conservancy Vocational College Rizhao 276826China School of Mechanical and Energy Engineering Ningbotech UniversityNingbo 315211China

Elucidating the flow features around piles in local scouring processes is crucial for studies of local scouring mechanisms and scour depth *** study details the flow turbulence characteristics of two submerged piles that are determined by solving the Navier-Stokes equations with the improved delayed detached eddy simulation *** model is verified by comparing experimental and numerical results for hydrodynamic parameters with the literature for both square-crossing piles(SCPs)and circular-crossing piles(CCPs).Original topographies of flat and scoured beds(i.e.,the initial and equilibrium scouring stages)are based on experimental results obtained by the authors in the present *** and CCP flow features in the scouring process are *** results indicate that during the scouring process,the time-averaged drag coefficient and root mean square(rms)of the lift coefficient increase linearly in the CCP test,while the rms of the lift coefficient in the SCP test decreases ***,the minimum pressure coefficient is always located in the upstream corners in the SCP case but moves from 72.5°to 79.5°when the scour hole is completely developed in the CCP *** flow behind the pile,which is generated by separated boundary layers above the top face of the pile,can reach the sand bed and turn the separated shear layers into patches of small vortices in the near-wake ***,the high shear stress z.nes are mainly at the scour edges under scoured-bed conditions.

关键词： flat bed scoured bed local scour OpenFOAM bed shear stress

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

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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

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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 analyz. 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 optimiz.d 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

Climate Changes and Sustainability

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Open Journal of Ecology 2024年第1期14卷 17-53页

作者： Kholoud z. Ghanem Department of Biological Science College of Science & Humanities Shaqra University Riyadh Saudi Arabia

Climate change is the phrase used to describe long-term changes in temperatures and weather patterns. Changes in the atmosphere and their interactions with diverse geologic, chemical, biological, and geographic variables are the main contributors to this cyclical adjustment of the Earth’s climate. Such changes may be induced purposefully, because of burning fossil fuels, clearing forests, and raising animals, or they may be natural, brought on by significant volcanic eruptions or variations in the sun’s activity. By significantly increasing the amount of greenhouse gases already in the atmosphere, this heightens the greenhouse effect and contributes to global warming. This work includes several additional theoretical and practical explanations of sustainable development. The theoretical work encompasses hundreds of researches that identify requirements for how development routes might satisfy sustainable development (SD) criteria using economic theory, complex systems approach, ecological science, and other techniques. The agreements made by the Parties in various nations across the world will consider a wide range of perspectives about what would be considered undesirable effects on the environment, the climate system, sustainability, economic growth, or food production.

关键词： Earth System Ancient Climatic Changes Causes of Climatic Changes Ecological Risk Assessment Ecosystem Abrupt Climate Change of Earth Sustainability

Floating Waste Discovery by Request via Object-Centric Learning

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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 localiz.ng 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 utiliz.s 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

On building automation system security

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High-Confidence Computing 2024年第3期4卷 103-122页

作者： Christopher Morales-Gonz.lez.Matthew Harper Michael Cash Lan Luo z.en Ling Qun z.Sun Xinwen fu Department of Computer Science University of Massachusetts LowellLowell 01854USA Department of Electrical and Computer Engineering University of Central FloridaOrlando 32816USA School of Computer Science and Technology Southeast UniversityMa’anshan 243032China School of Computer Science and Engineering Anhui University of TechnologyNanjing 211189China

Building Automation Systems(BASs)are seeing increased usage in modern society due to the plethora of benefits they provide such as automation for climate control,HVAC systems,entry systems,and lighting *** BASs in use are outdated and suffer from numerous vulnerabilities that stem from the design of the underlying BAS *** this paper,we provide a comprehensive,up-to-date survey on BASs and attacks against seven BAS protocols including BACnet,EnOcean,KNX,LonWorks,Modbus,z.gBee,and *** studies of secure BAS protocols are also presented,covering BACnet Secure Connect,KNX Data Secure,KNX/IP Secure,ModBus/TCP Security,EnOcean High Security and z.Wave *** and z.gBee do not have security *** point out how these security protocols improve the security of the BAS and what issues remain.A case study is provided which describes a real-world BAS and showcases its vulnerabilities as well as recommendations for improving the security of *** seek to raise awareness to those in academia and industry as well as highlight open problems within BAS security.

关键词： Building automation system BAS protocols Security Attack

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

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

作者： z.wang 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