检索结果-南通市图书馆

Fragility crossover mediated by covalent-like electronic interactions in metallic liquids

在线全文

学校读者我要写书评

暂无评论

Materials Futures

Materials Futures 2024年第2期3卷 117-130页

作者： Hui-Ru zhang Liang Gao Yu-Hao Ye jia-xin zhang Tao zhang Qing-Zhou Bu Qun Yang Zeng-Wei Zhu Shuai Wei Hai-Bin Yu Wuhan National High Magnetic Field Center and School of Physics Huazhong University of Science and TechnologyWuhan 430074People’s Republic of China Department of Chemistry Aarhus University8000 AarhusDenmark iMAT Centre for Integrated Materials Research Aarhus University8000 AarhusDenmark

Fragility is one of the central concepts in glass and liquid sciences,as it characterizes the extent of deviation of viscosity from Arrhenius behavior and is linked to a range of glass ***,the intervention of crystallization often prevents the assessment of fragility in poor glass-formers,such as supercooled metallic *** experimental data on their compositional dependence are scarce,let alone fundamentally *** this work,we use fast scanning calorimetry to overcome this obstacle and systematically study the fragility in a ternary La–Ni–Al system,over previously inaccessible composition *** observe fragility dropped in a small range with the Al alloying,indicating an alloying-induced fragility *** use x-ray photoelectron spectroscopy,resistance measurements,electronic structure calculations,and DFT-based deep-learning atomic simulations to investigate the cause of this fragility *** results show that the fragility crossover can be fundamentally ascribed to the electronic covalency associated with the unique Al–Al *** findings provide insight into the origin of fragility in metallic liquids from an electronic structure perspective and pave a new way for the design of metallic glasses.

关键词： metallic glass fragility fast scanning calorimetry density functional theory deep learning potential

Distributed collaborative complete coverage path planning based on hybrid strategy

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

Journal of Systems Engineering and Electronics 2024年第2期35卷 463-472页

作者： zhang jia DU xin DONG Qichen xin Bin School of Automation Beijing Institute of TechnologyBeijing 100081China National Key Laboratory of Autonomous Intelligent Unmanned Systems Beijing Institute of TechnologyBeijing 100081China

Collaborative coverage path planning(CCPP) refers to obtaining the shortest paths passing over all places except obstacles in a certain area or space. A multi-unmanned aerial vehicle(UAV) collaborative CCPP algorithm is proposed for the urban rescue search or military search in outdoor *** to flexible control of small UAVs, it can be considered that all UAVs fly at the same altitude, that is, they perform search tasks on a two-dimensional plane. Based on the agents’ motion characteristics and environmental information, a mathematical model of CCPP problem is established. The minimum time for UAVs to complete the CCPP is the objective function, and complete coverage constraint, no-fly constraint, collision avoidance constraint, and communication constraint are considered. Four motion strategies and two communication strategies are designed. Then a distributed CCPP algorithm is designed based on hybrid strategies. Simulation results compared with patternbased genetic algorithm(PBGA) and random search method show that the proposed method has stronger real-time performance and better scalability and can complete the complete CCPP task more efficiently and stably.

关键词： multi-agent cooperation unmanned aerial vehicles(UAV) distributed algorithm complete coverage path planning(CCPP)

SDCC: software-defined collective communication for distributed training

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第9期67卷 105-125页

作者： xin JIN Zhen zhang Yunshan jia Yun MA Xuanzhe LIU School of Computer Science Peking University Department of Computer Science and Technology Johns Hopkins University

Communication is crucial to the performance of distributed training. Today's solutions tightly couple the control and data planes and lack flexibility, generality, and performance. In this study, we present SDCC, a software-defined collective communication framework for distributed training. SDCC is based on the principle of modern systems design to effectively decouple the control plane from the data *** abstracts the operations for collective communication in distributed training with dataflow operations and unifies computing and communication with a single dataflow graph. The abstraction, together with the unification, is powerful: it enables users to easily express new and existing collective communication algorithms and optimizations, simplifies the integration with different computing engines(e.g., Py Torch and Tensor Flow) and network transports(e.g., Linux TCP and kernel bypass), and allows the system to improve performance by exploiting parallelism exposed by the dataflow graph. We further demonstrate the benefits of SDCC in four use cases.

关键词： machine learning systems distributed training deep learning collective communication software-defined networking

Optimum design of hierarchical stiffened shells for low imperfection sensitivity

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2014年第3期30卷 391-402页

作者： Bo Wang Peng Hao Gang Li jia-xin zhang Kai-Fan Du Kuo Tian Xiao-Jun Wang Xiao-Han Tang State Key Laboratory of Structural Analysis for Industrial Equipment Department of Engineering MechanicsDalian University of Technology Beijing Institute of Astronautical Systems Engineering

A concept of hierarchical stiffened shell is proposed in this study, aiming at reducing the imperfection sen- sitivity without adding additional weight. Hierarchical stiffened shell is composed of major stiffeners and minor stiff- eners, and the minor stiffeners are generally distributed between adjacent major stiffeners. For various types of geo- metric imperfections, e.g., eigenmode-shape imperfections, hierarchical stiffened shell shows significantly low imper- fection sensitivity compared to traditional stiffened shell. Furthermore, a surrogate-based optimization framework is proposed to search for the hierarchical optimum design. Then, two optimum designs based on two different opti- mization objectives （including the critical buckling load and the weighted sum of collapse loads of geometrically imperfect shells with small- and large-amplitude imperfections） are compared and discussed in detail. The illustrative example demonstrates the inherent superiority of hierarchical stiffened shells in resisting imperfections and the effectiveness of the proposed framework. Moreover, the decrease of imperfection sensitivity can finally be converted into a decrease of structural weight, which is particularly important in the development of large-diameter launch vehicles.

关键词： Hierarchical stiffened shell Imperfection sensi-tivity Collapse Optimization

Study on the Characteristics of the Gas Switch Electrode Erosion

在线全文

学校读者我要写书评

暂无评论

高压电器 2011年第9期47卷 6-11页

作者： WANG Hu CHANG jia-sen TONG xin zhang Qiao-gen QIU Ai-ci School of Electrical Engineering Xi'an Jiaotong University Xi'an 710049 China

Gas spark switch is one of the key parts in pulsed power *** erosion has great influence on the switch performance and *** this paper,a field distortion gas switch is selected for the experiment and a great deal of discharging experiments have been conducted in different test *** forming process of etch pit as well as its influencing factors is discussed briefly and surface roughness coefficient(SRC) of the electrode is put forward to evaluate the state of electrode *** results show that current peak plays an important role in electrode erosion when waveforms of discharge current are the same,and electric charge and oscillation frequency of discharge current also have great effect on the electrode erosion when waveforms of discharge current are *** the increase of discharge times,SRC decreases slowly at first and then decreases quickly after three thousand of discharge times.

关键词： erosion etch pit surface roughness coefficient gas switch

Therapeutic strategies of targeting nonapoptotic regulated cell death (RCD) with smallmolecule compounds in cancer

在线全文

学校读者我要写书评

暂无评论

Acta Pharmaceutica Sinica B 2024年第7期14卷 2815-2853页

作者： xin Jin Wenke Jin Linlin Tong jia Zhao Lan zhang Na Lin Department of Ultrasound Department of Medical Oncology and Department of Hematologythe First Hospital of China Medical UniversityChina Medical UniversityShenyang 110001China Sichuan Engineering Research Center for Biomimetic Synthesis of Natural Drugs School of Life Science and EngineeringSouthwest Jiaotong UniversityChengdu 610031China

Regulated cell death(RCD)is a controlled form of cell death orchestrated by one or more cascading signaling pathways,making it amenable to pharmacological *** subroutines can be categorized as apoptotic or non-apoptotic and play essential roles in maintaining homeostasis,facilitating development,and modulating *** evidence has recently revealed that RCD evasion is frequently the primary cause of tumor *** non-apoptotic RCD subroutines have garnered attention as promising cancer therapies due to their ability to induce tumor regression and prevent relapse,comparable to ***,they offer potential solutions for overcoming the acquired resistance of tumors toward apoptotic *** an increasing understanding of the underlying mechanisms governing these non-apoptotic RCD subroutines,a growing number of small-molecule compounds targeting single or multiple pathways have been discovered,providing novel strategies for current cancer *** this review,we comprehensively summarized the current regulatory mechanisms of the emerging non-apoptotic RCD subroutines,mainly including autophagy-dependent cell death,ferroptosis,cuproptosis,disulfidptosis,necroptosis,pyroptosis,alkaliptosis,oxeiptosis,parthanatos,mitochondrial permeability transition(MPT)-driven necrosis,entotic cell death,NETotic cell death,lysosome-dependent cell death,and immunogenic cell death(ICD).Furthermore,we focused on discussing the pharmacological regulatory mechanisms of related small-molecule *** brief,these insightful findings may provide valuable guidance for investigating individual or collaborative targeting approaches towards different RCD subroutines,ultimately driving the discovery of novel small-molecule compounds that target RCD and significantly enhance future cancer therapeutics.

关键词： Regulated cell death(RCD) Non-apoptotic RCD subroutine Autophagy Ferroptosis Necroptosis Regulatory mechanism Small-molecule compound Cancer therapy

Construction of RuO2-Ru/MoO2@carbon cloth bifunctional electrocatalyst for efficient overall water splitting

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

Rare Metals 2024年第10期43卷 5095-5104页

作者： jia-Lin Cai Jing-Yi Fan Xu-Dong zhang xin Xie Wan-Yu Tian xin-Gang zhang Jie Ding Yu-Shan Liu College of Material Henan Key Laboratory of Aeronautical Materials and Application TechnologyZhengzhou University of Aeronautics The Green Catalysis Center and College of ChemistryZhengzhou University

Efficient bifunction electrocatalyst is extremely interesting for electrochemical overall water splitting （OWS）.Herein,a new RuO2-Ru/MoO2@CC（RRM/CC） bifunctional electrocatalyst was prepared via a solid phase reaction *** obtain a suitable precursor for SPR,MoS2nanosheets and RuO2nanoparticles （NPs）were sequentially loaded onto carbon cloth conductive ***,the prepared RuO2/MoS2/CC precursor was sealed in a furnace and annealed in Ar to trigger the redox *** SPR,active RuO2-Ru/MoO2units containing metal–metal oxide interfaces were formed on CC substrate *** optimized RRM/CC sample annealed at 400℃ exhibited a overpotential of 13 m V for hydrogen evolution reaction （HER） and 231 mV for oxygen evolution reaction （OER） at 10 mA·cm-2under alkaline condition,respectively,which can be deduced to the modulated electronic structure and unique hierarchica *** addition,a low cell voltage of 1.48 V for OWS was required at 10 mA·cm-2under alkaline condition Meanwhile,RRM/CC exhibited excellent pH-independent durability.

关键词： Bifunctional Electrocatalyst Overall water splitting Ru RuO2

Photophysical properties of nitrogen-doped carbon quantum dots synthesized by graphite

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Materiomics 2024年第4期10卷 828-836页

作者： jia Liu Hailong Yu Guan Wang Shuang Yang Meichen Li xin zhang Yang jia Yachen Gao School of Electronic Engineering Heilongjiang UniversityHarbin150080HeilongjiangChina College of Communication and Electronic Engineering Qiqihar UniversityQiqihar161000HeilongjiangChina

Here,nitrogen-doped carbon quantum dots(N-CQDs)were successfully synthesized by the solvothermal method using graphite as the carbon source and N,N-dimethylformamide as the nitrogen *** characterized the structure and chemical constitution of N-CQDs using X-ray diffraction,Fourier transform infrared spectroscopy and X-ray photoelectron *** investigated the pump-and temperature-dependent photoluminescence(PL)properties and the dynamic exciton recombination processes of N-CQDs,using both steady-state and time-resolved PL *** spectral results show that the PL emission peak located at 518 nm at room temperature,mainly originates from the n-π∗transition on the surface of *** pump fluence and PL integral intensity were analyzed to demonstrate the existence of single-photon excitation under the 405 nm laser *** the temperature increases,the non-radiative transition gradually increases,which decreases the PL intensity,the full width at half maxima first narrows and then widens and the PL lifetime gradually ***,we combined the N-CQDs with chip to prepare light-emitting diode(LED).The resulting chromaticity coordinate was obtained to be(0.29,0.40).This study offers a comprehensive understanding of the luminescence mechanism in N-doped CQDs and introduces a novel approach for the quickly fabrication of full-color display LEDs.

关键词： Carbon quantum dots Nitrogen-doped Photoluminescence Temperature-dependent Non-radiative transition

An electron-transfer[Fe_(2)Co_(2)]square complex exhibiting unprecedented wide room-temperature hysteresis

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

Science China Chemistry 2024年第4期67卷 1198-1207页

作者： xin-Hua Zhao Yi-Fei Deng jia-Tao Chen Jiong Yang Yuan-Zhu zhang Department of Chemistry Southern University of Science and Technology(SUSTech)Shenzhen 518055China

Switchable molecules with magnetic bistability that can function at standard conditions are highly desirable from the perspective of practical *** the last decade,significant progress has been made in modulating thermally induced electrontransfer-coupled spin transition(ETCST)events between diamagnetic{Fe_(LS)^(Ⅱ)(μ-CN)Co_(LS)^(Ⅲ)}and paramagnetic{Fe_(LS)^(Ⅲ)(μ-CN)-Co_(HS)^(Ⅱ)}electron configurations(named LS and HS,respectively,for short)within the Fe/Co mixed-valence cyanometallate ***,we prepared a novel[Fe_(2)Co_(2)]square complex[(pzTp)Fe(CN)_(3)Co(bnbpen)]_(2)[NO_(3)]_(2)·4CH_(3)OH·2.5H_(2)O(1·Solv)and its desolvated phase[(pzTp)Fe(CN)_(3)Co(bnbpen)]_(2)[NO_(3)]_(2)(1),obtained via single-crystal-to-single-crystal(SCSC)*** 1·Solv remaining in the diamagnetic state below room temperature exhibits an irreversible ETCST behavior accompanied by desolvation upon ***,complex 1 displays an unprecedented rate-dependent ETCST behaviour involving with two diamagnetic LS states(a dynamically favoured LS1 state and a thermodynamically favoured LS2state),between which a net one-way transition from LS1 to LS2 is accessible likely via a structural phase transition(SPT)above255 ***,two well separated transition channels(HS?LS1 at around 255 K and HS←→LS2 in the temperature range of 317-350 K)are achieved according to either fast(>20 K/min)or slow rate(<1 K/min),*** a moderate rate of 3 K/min,complex 1 shows a wide hysteresis of 66 K centered at 328 K,the largest yet reported for discrete Fe/Co cyanometallate *** 1 represents the first ETCST example coupled with dynamic SPT,providing a new strategy for manipulating bistability within this fascinating cyanometallate family.

关键词： switchable molecules cyanometallate complexes electron transfer hysteresis structural phase transition