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Flat Band and η-Pairing States in a One-Dimensional MoiréHubbard Model

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Chinese Physics Letters 2024年第4期41卷 69-76页

作者：王冉宋智 College of Physics and Materials Science Tianjin Normal UniversityTianjin 300387China School of Physics Nankai UniversityTianjin 300071China

A Moirésystem is formed when two periodic structures have a slightly mismatched period,resulting in unusual strongly correlated states in the presence of particle-particle *** periodic structures can arise from the intrinsic crystalline order and periodic external *** investigate a one-dimensional Hubbard model with periodic on-site potential of period n_(0),which is commensurate to the lattice *** large n_(0),the exact solution demonstrates that there is a midgap flat band with zero energy in the absence of Hubbard *** Moiréunit cell contributes two zero energy levels to the flat *** the presence of Hubbard interaction,the midgap physics is demonstrated to be well described by a uniform Hubbard chain in which the effective hopping and on-site interaction strength can be controlled by the amplitude and period of the external *** simulations are performed to demonstrate the correlated behaviors in the finite-sized Moiré Hubbard system,including the existence of an η-pairing state and bound pair *** finding provides a method to enhance the correlated effect by a spatially periodic external field.

关键词： oscillation interaction field

A concise review on surface and structural modification of porous zeolite scaffold for enhanced hydrogen storage

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Chinese Journal of Chemical Engineering 2024年第6期70卷 33-53页

作者： B.A.Abdulkadir r.S.r.Mohd Zaki A.T.Abd Wahab S.N.Miskan Anh-Tam Nguyen Dai-Viet N.Vo H.D.Setiabudi Centre for research in Advanced Fluid&Processes Universiti Malaysia Pahang Al-Sultan AbdullahLebuh Persiaran Tun Khalil YaakobGambangPahang 26300Malaysia Faculty of Chemical&Process Engineering Technology Universiti Malaysia Pahang Al-Sultan AbdullahLebuh Persiaran Tun Khalil YaakobGambangPahang 26300Malaysia Center of Excellence for Green Energy and Environmental Nanomaterials(CE@GrEEN) Nguyen Tat Thanh University300A Nguyen Tat ThanhDistrict 4Ho Chi Minh City 755414Viet Nam

Investigating zeolites as hydrogen storage scaffolds is imperative due to their porous nature and favorable physicochemical ***,the storage capacity of the unmodified zeolites has been rather unsatisfactory(0.224%-1.082%(mass))compared to its modified ***,the contemporary focus on enhancing hydrogen storage capacities has led to significant attention towards the utilization of modified zeolites,with studies exploring surface modifications through physical and chemical treatments,as well as the integration of various active *** enhanced hydrogen storage properties of zeolites are attributed to the presence of aluminosilicates from alkaline and alkaline-earth metals,resulting in increased storage capacity through interactions with the charge density of these ***,there is a great demand to critically review their role such as well-defined topology,pore structure,good thermal stability,and tunable hydrophilicity in enhanced hydrogen *** article aimed to critically review the recent research findings based on modified zeolite performance for enhanced hydrogen *** of the factors affecting the hydrogen storage capacities of zeolites that can affect the rate of reaction and the stability of the adsorbent,like pressure,structure,and morphology were studied,and ***,future perspectives,recommendations,and directions for modified zeolites were discussed.

关键词： Zeolites Hydrogen storage Surface modification Adsorption Active metal

Efficient contraflow algorithms for quickest evacuation planning

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Science China Mathematics 2018年第11期61卷 2079-2100页

作者： Urmila Pyakurel Hari Nandan nath Tanka nath Dhamala Central Department of Mathematics Tribhuvan University Department of Mathematics Bhaktapur Multiple Campus Tribhuvan University

The optimization models and algorithms with their implementations on flow over time problems have been an emerging field of research because of largely increasing human-created and natural disasters *** an optimal use of transportation network to shift affected people and normalize the disastrous situation as quickly and efficiently as possible,contraflow configuration is one of the highly applicable operations research(Or)*** increases the outbound road capacities by reversing the direction of arcs towards the safe destinations that not only minimize the congestion and increase the flow but also decrease the evacuation time *** this paper,we sketch the state of quickest flow solutions and solve the quickest contraflow problem with constant transit times on arcs proving that the problem can be solved in strongly polynomial time O(nm^2(long n)~2)where n and m are number of nodes and number of arcs,respectively in the *** contraflow solution has the same computational time bound as that of the best min-cost flow ***,we also introduce the contraflow approach with load dependent transit times on arcs and present an efficient algorithm to solve the quickest contraflow problem *** the claim,our computational experiments on Kathmandu road network and on randomly generated instances perform very well matching the theoretical *** a sufficiently large number of evacuees,about double flow can be shifted with the same evacuation time and about half time is sufficient to push the given flow value with contraflow reconfiguration.

关键词： evacuation planning contraflow flow over time quickest flow load dependent transit time

Development and experimental investigation of duplex turning process

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Advances in Manufacturing 2017年第2期5卷 149-157页

作者： ravindra nath Yadav Department of Mechanical Engineering BBD National Institute of Technology and Management Lucknow 226028India

The aim of the present study was to develop a novel turning process with the simultaneous application of two cutting tools in place of a single cutting tool during machining of rotating surfaces. This process is referred to as duplex turning, and is used to eliminate the need for a secondary final cut operation following the turning process. To achieve this, a secondary （auxiliary） tool post is mounted on the cross slide of the centre lathe machine after fabrication. The secondary tool post is used to hold a secondary cutting tool that penetrates the workpiece from opposite side of the primary cutting tool to perform the finish cut operation during turn machining of the cylin- drical workpiece. The performance of the developed process was tested on AISI 1040 alloy steel, using two single point cutting tools made of high speed steel. The effects of cutting velocity, feed rate, primary depth of cut and secondary depth of cut were analyzed and discussed with regard to average surface roughness, and were also compared with normal turning process. From the results, it was concluded that duplex turning process was capable of providing better surface finishes compared to those generated by normal turning. It was also found that higher cutting velocity yielded better surface finishes within the determined ranges of the selected parameters.

关键词： Cutting Design of experiment Machining Surface roughness Turning

Psychosocial interventions for infertile couples:A scoping review

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Asian pacific Journal of reproduction 2024年第3期13卷 97-106页

作者： Sreemol Sunil Anish K.r. rajagiri College of Social Sciences KalamasseryKeralaIndia

Objective:To bring out current evidence regarding psycho-social interventions for infertility care,and identify the best practices in clinical ***:An in-depth literature review on infertility care intervention was conducted using data from multiple databases:PubMed,EMBASE,Google Scholar,and *** relevant articles selected were between 2008 and ***:A literature search turned up 1798 citations,of which 25 studies were included after rigorous *** intervention categories have been constantly utilised to provide support and promote mental health,of which acceptance and commitment therapy(ACT)and cognitive behaviour therapy(CBT)were used most *** interventions exhibited diversity in both content and composition,and addressed a wide range of ***:The review emphasizes that psycho-social interventions have a positive effect on psychological issues,relationships,and pregnancies among couples and can be incorporated into fertility-care practices.

关键词： Infertile couples Psychosocial interventions Mental health Quality of life

A Facial Expression recognition Method Integrating Uncertainty Estimation and Active Learning

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Computers, Materials and Continua 2024年第1期81卷 533-548页

作者： Wang Y. Zhang J. Sun r. School of Computer Science and Engineering Chongqing University of Technology Chongqing 400054 China Data Space research Institute of Hefei Comprehensive National Science Center Hefei 230088 China

The effectiveness of facial expression recognition (FEr) algorithms hinges on the model’s quality and the availability of a substantial amount of labeled expression data. However, labeling large datasets demands significant human, time, and financial resources. Although active learning methods have mitigated the dependency on extensive labeled data, a cold-start problem persists in small to medium-sized expression recognition datasets. This issue arises because the initial labeled data often fails to represent the full spectrum of facial expression characteristics. This paper introduces an active learning approach that integrates uncertainty estimation, aiming to improve the precision of facial expression recognition regardless of dataset scale variations. The method is divided into two primary phases. First, the model undergoes self-supervised pre-training using contrastive learning and uncertainty estimation to bolster its feature extraction capabilities. Second, the model is fine-tuned using the prior knowledge obtained from the pre-training phase to significantly improve recognition accuracy. In the pre-training phase, the model employs contrastive learning to extract fundamental feature representations from the complete unlabeled dataset. These features are then weighted through a self-attention mechanism with rank regularization. Subsequently, data from the low-weighted set is relabeled to further refine the model’s feature extraction ability. The pre-trained model is then utilized in active learning to select and label information-rich samples more efficiently. Experimental results demonstrate that the proposed method significantly outperforms existing approaches, achieving an improvement in recognition accuracy of 5.09% and 3.82% over the best existing active learning methods, Margin, and Least Confidence methods, respectively, and a 1.61% improvement compared to the conventional segmented active learning method. © 2024 The Authors.

关键词： active learning Expression recognition self-supervised learning uncertainty estimation

Single-atom Pt on carbon nanotubes for selective electrocatalysis

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Carbon Energy 2024年第1期6卷 63-71页

作者： Samuel S.Hardisty Xiaoqian Lin Anthony r.J.Kucernak David Zitoun Department of Chemistry Bar Ilan Institute of Nanotechnology and Advanced Materials(BINA)Bar Ilan UniversityRamat GanIsrael Department of Chemistry Molecular Science Research HubImperial College LondonLondonUK

Utilizing supported single atoms as catalysts presents an opportunity to reduce the usage of critical raw materials such as platinum,which are essential for electrochemical reactions such as hydrogen oxidation reaction(HOr).Herein,we describe the synthesis of a Pt single electrocatalyst inside single-walled carbon nanotubes(SWCNTs)via a redox *** via electron microscopy,X-ray photoelectron microscopy,and X-ray absorption spectroscopy show the single-atom nature of the *** electrochemical behavior of the sample to hydrogen and oxygen was investigated using the advanced floating electrode technique,which minimizes mass transport limitations and gives a thorough insight into the activity of the *** single-atom samples showed higher HOr activity than state-of-the-art 30%Pt/C while almost no oxygen reduction reaction activity in the proton exchange membrane fuel cell operating *** selective activity toward HOr arose as the main fingerprint of the catalyst confinement in the SWCNTs.

关键词： confinement electrocatalysis hydrogen platinum single atom catalysts

Strengthening Active Aging through Older People’s Association and Economic Activity of the Older People in Nepal

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Getting the Most Out of Every Training Day: The Influence of Instructors on Self-regulated Learning During Firefighter Leadership Courses

Advances in Aging research（老年问题研究） 2024年第2期 15页

作者： Hom nath Chalise James Brightman

来源：博看期刊评论

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International Journal of Disaster risk Science 2024年第3期15卷 332-345页

作者： Stefan r?seler Micha Hilbert Guido Hertel Meinald T.Thielsch Department of Psychology University of Münster

Leadership courses in the fire services are highly challenging, and they can seriously exhaust trainees and hamper their selfregulated learning efforts(for example, setting goals, focusing attention, seeking feedback). We theorize that experiences of failure or overload can curtail trainees' available energy resources on subsequent training days, which, in turn, should affect trainees' learning efforts. Given instructors' central role in leadership courses, we hypothesize that supportive and humble instructor behaviors decrease experiences of failure and overload and, thus, increase self-regulated learning. Moreover, we argue that supportive instructor behavior may amplify the positive effects of high energy resources, while humble behavior may alleviate the negative impact of low resource levels. We tested preregistered hypotheses with 118 firefighters participating in two-week leadership courses at a German fire academy. The participants completed short web-based questionnaires before and after classes each day. Multilevel analyses confirmed that perceived daily supportive and humble instructor behavior predicted trainees' reports of daily self-regulated learning activity. Notably, this effect was independent from positive effects of trainees' reported energy resources in the morning. Supportive and humble behavior did not moderate the eff ect of energy resources. Our findings suggest that instructors play a crucial role in facilitating effective learning under challenging training conditions. Furthermore, we offer implications for leaders in fire services, who often conduct trainings with their subordinates.

关键词： Diary study Fire services Instructor behavior Leadership training resource investment