检索结果-南通市图书馆

Nearly degenerate ground states of a checkerboard antiferromagnet and their bosonic interpretation

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第1期67卷 84-89页

作者： Haiyuan Zou Fan Yang Wei Ku key {1. of Polar Materials and Devices(MOE) School of Physics and Electronic ScienceEast China Normal UniversityShanghai 200241China Department of Physics Beijing Institute of TechnologyBeijing 100081China Tsung-Dao Lee Institute Shanghai 200240China key {1. of Artificial Structures and Quantum Control(Ministry of Education) Shanghai 200240China shanghai Branch Hefei National LaboratoryShanghai 201315China

The spin-1.2 model system with antiferromagnetic(AF) couplings on a J1.J2checkerboard lattice, known as the planar pyrochlore model, is strongly frustrated and associated with a two-to-one dimensional crossover. Using the Projected Entangled Simplex States tensor network ansatz, we identify a large number of nearly degenerate states in the frustrated region(J_(1.1.≤J_(2), while various 1. AF correlated states take over the rest. We verify the stability of the VBS state against nematic perturbation. The corresponding bosonic picture provides an intuitive understanding of the low-energy physics. Particularly, it predicts weaker VBS states in the easy-plane limit, which we confirm numerically. Our results clarify the most essential ground state properties of this interesting system and demonstrate the usefulness of bosonic picture in dealing with frustrated magnetism.

关键词： tensor networks frustrated magnetism dimensional crossover degenerate states

Research progress of quantum artificial intelligence in smart city

在线全文

学校读者我要写书评

暂无评论

Intelligent and Converged Networks 2024年第2期5卷 116-133页

作者： Sumin Wang Ning Wang Tongyu Ji Yiyun Shi Chao Wang the Joint International Research laboratory of Specialty Fiber Optics and Advanced Communication Shanghai UniversityShanghai 200444China School of Information Engineering Ganzhou Key Laboratory of Cloud Computing and Big Data ResearchGannan University of Science and TechnologyGanzhou 341000China

The rapid accumulation of big data in the Internet era has gradually decelerated the progress of Artificial Intelligence(AI).As Moore’s Law approaches its limit,it is imperative to break the constraints that are holding back artificial *** computing and artificial intelligence have been advancing along the highway of human civilization for many years,emerging as new engines driving economic and social *** article delves into the integration of quantum computing and artificial intelligence in both research and *** introduces the capabilities of both universal quantum computers and special-purpose quantum computers that leverage quantum *** discussion further explores how quantum computing enhances classical artificial intelligence from four perspectives:quantum supervised learning,quantum unsupervised learning,quantum reinforcement learning,and quantum deep *** an effort to address the limitations of smart cities,this article explores the formidable potential of quantum artificial intelligence in the realm of smart *** does so by examining aspects such as intelligent transportation,urban operation assurance,urban planning,and information communication,showcasing a plethora of practical achievements in the *** the foreseeable future,Quantum Artificial Intelligence(QAI)is poised to bring about revolutionary development to smart *** urgency lies in developing quantum artificial intelligence algorithms that are compatible with quantum computers,constructing an efficient,stable,and adaptive hybrid computing architecture that integrates quantum and classical computing,preparing quantum data as needed,and advancing controllable qubit hardware equipment to meet actual *** ultimate goal is to shape the next generation of artificial intelligence that possesses common sense cognitive abilities,robustness,excellent generalization capabilities,and interpretability.

关键词： quantum artificial intelligence smart city D-Wave quantum computer

Micelle-directed self-assembly of single-crystal-like mesoporous stoichiometric oxides for high-performance lithium storage

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

National Science Review 2024年第4期11卷 195-205页

作者： Yanhua Wan Changyao Wang Xingmiao Zhang Yang Yin Mengmeng Liu Bing Ma Linlin Duan Yuzhu Ma Wei Zhang Changlin Zheng Dongliang Chao Fei Wang Yongyao Xia Wei Li Department of Chemistry Laboratory of Advanced Materials Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials State Key Laboratory of Molecular Engineering of Polymers College of Chemistry and Materials ScienceFudan University State key {1. of Surface Physics and Department of Physics Fudan University

Due to their uncontrollable assembly and crystallization process,the synthesis of mesoporous metal oxide single crystals remains a formidable ***,we report the synthesis of single-crystal-like mesoporous Li2TiSiO5by using soft micelles as *** key lies in the atomic-scale self-assembly and step-crystallization processes,which ensure the formation of single-crystal-like mesoporous Li2TiSiO5microparticles via an oriented attachment growth mechanism under the confinement of an in-situ formed carbon *** mesoporous Li2TiSiO5anode achieves a superior rate capability(1.8 mAh g-1.t5.0 A g-1. and outstanding long-term cycling stability(1.8 mAh g-1.fter 3000 cycles at 2.0 A g-1. for lithium storage as a result of the ultrafast Li+diffusion caused by penetrating mesochannels and nanosized crystal frameworks（5-1. nm）.In comparison,bulk Li2TiSiO5exhibits poor rate capability and cycle performance due to micron-scale diffusion *** method is very simple and reproducible,heralding a new way of designing and synthesizing mesoporous single crystals with controllable frameworks and chemical functionalities.

关键词： mesoporous materials micelles single-crystal-like Li2TiSiO5 lithium-ion batteries

Physical neural networks with self-learning capabilities

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第8期67卷 23-42页

作者： Weichao Yu Hangwen Guo Jiang Xiao Jian Shen State key {1. of Surface Physics and Institute for Nanoelectronic Devices and Quantum computing Fudan UniversityShanghai 200433China Zhangjiang Fudan International Innovation Center Fudan UniversityShanghai 201210China Department of Physics Fudan UniversityShanghai 200433China shanghai Research Center for Quantum Sciences Shanghai 201315China Collaborative Innovation Center of Advanced Microstructures Nanjing 210093China

Physical neural networks are artificial neural networks that mimic synapses and neurons using physical systems or *** networks harness the distinctive characteristics of physical systems to carry out computations effectively,potentially surpassing the constraints of conventional digital neural networks.A recent advancement known as“physical self-learning”aims to achieve learning through intrinsic physical processes rather than relying on external *** article offers a comprehensive review of the progress made in implementing physical self-learning across various physical *** learning strategies that contribute to the realization of physical self-learning are *** challenges in understanding the fundamental mechanism of learning,this work highlights the progress towards constructing intelligent hardware from the ground up,incorporating embedded self-organizing and self-adaptive dynamics in physical systems.

关键词： self-learning physical neural networks neuromorphic computing physical learning

An oscillation-free Hermite WENO scheme for hyperbolic conservation laws

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2024年第2期67卷 431-454页

作者： Zhuang Zhao Jianxian Qiu School of Mathematical Sciences and Institute of Natural Sciences Shanghai Jiao Tong UniversityShanghai 200240China School of Mathematical Sciences and Fujian Provincial key {1. of Mathematical Modeling and High-Performance Scientific computing Xiamen UniversityXiamen 361005China

In this paper, the sixth-order oscillation-free Hermite weighted essentially non-oscillatory (OFHWENO) scheme is proposed for hyperbolic conservation laws on structured meshes, where the zeroth- andfirst-order moments are the variables for the governing equations. The main difference from other HWENOschemes existing in the literature is that we add high-order numerical damping terms in the first-order momentequations to control spurious oscillations for the OF-HWENO scheme. The OF-HWENO scheme not only canachieve the designed optimal numerical order, but also can be easily implemented as we use only one set ofstencils in the reconstruction procedure and the same reconstructed polynomials are applied for the zeroth- andfirst-order moment equations. In order to obtain the adaptive order resolution when facing discontinuities, atransition polynomial is added in the reconstruction, where the associated linear weights can also be any positivenumbers as long as their summation equals one. In addition, the OF-HWENO scheme still keeps compactnessas only immediate neighbor values are needed in the space discretization. Some benchmark numerical tests areperformed to illustrate the high-order accuracy, high resolution and robustness of the proposed scheme.

关键词： Hermite WENO scheme hyperbolic conservation laws oscillation-free adaptive order discontinuous Galerkin method

Phosphotungstic acid immobilized on amino-functionalized TS-1.zeolite as a solid acid catalyst for the synthesis of tributyl citrate

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2024年第6期70卷 199-210页

作者： Pei Li Bianfang Shi Junyao Shen Ran Cui Wenze Guo Ling Zhao Zhenhao Xi State key {1. of Chemical Engineering East China University of Science and TechnologyShanghai 200237China key {1. of Smart Manufacturing in Energy Chemical Process Ministry of EducationEast China University of Science and TechnologyShanghai 200237China

The amino-functionalization of TS-1.zeolite followed by immobilization of phosphotungstic acid(HPW)was presented to prepare a strong solid acid catalyst for the synthesis of bio-based tributyl citrate from the esterification of citric acid and n-butanol.γ-Aminopropyltriethoxysilane(APTES)was first grafted on the TS-1.zeolite via the condensation reactions with surface hydroxyl groups,and subsequently the HPW was immobilized via the reaction between the amino groups and the protons from HPW-forming strong ionic *** Keggin structure of HPW and MFI topology of TS-1.zeolite were well maintained after the *** amino-functionalization generated abundant uniformly distributed active sites on TS-1.for HPW immobilization,which promoted the dispersity,abundance,as well as the stability of the acid *** tetrahedrally coordinated framework titanium and non-framework titania behaved as weak Lewis acid sites,and the protons from the immobilized HPW acted as the moderate or strong Brønsted acid *** optimized TBC yield of 96.2%(mol)with a conversion of-COOH of 98.1.(mol)was achieved at 1.0℃for 6 h over the HPW immobilized on amino-functionalized *** catalyst exhibited good stability after four consecutive reaction runs,where the activity leveled off at still a relatively high level after somewhat deactivation possibly caused by the leaching of a small portion of weakly anchored APTES or HPW.

关键词： Amino-functionalization Phosphotungstic acid TS-1.zeolite Esterification Tributyl citrate

Multi-party privacy-preserving decision tree training with a privileged party

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第8期67卷 253-268页

作者： Yiwen TONG Qi FENG Min LUO Debiao HE key {1. of Aerospace Information Security and Trusted computing Ministry of Education School of Cyber Science and Engineering Wuhan University shanghai Technology Innovation Centre of Distributed Privacy-Preserving Artificial Intelligence Matrix Elements Technologies key {1. of computing Power Network and Information Security Ministry of EducationShandong Computer Science Center Qilu University of Technology(Shandong Academy of Sciences)

Currently, a decision tree is the most commonly used data mining algorithm for classification tasks. While a significant number of studies have investigated privacy-preserving decision trees, the methods proposed in these studies often have shortcomings in terms of data privacy breach or efficiency. Additionally,these methods typically only apply to symmetric frameworks, which consist of two or more parties with equal privilege, and are not suitable for asymmetric scenarios where parties have unequal privilege. In this paper,we propose SecureCART, a three-party privacy-preserving decision tree training scheme with a privileged party. We adopt the existing pMPL framework and design novel secure interactive protocols for division,comparison, and asymmetric multiplication. Compared to similar schemes, our division protocol is 93.5–560.4× faster, with the communication overhead reduced by over 90%; further, our multiplication protocol is approximately 1.5× faster, with the communication overhead reduced by around 20%. Our comparison protocol based on function secret sharing maintains good performance when adapted to pMPL. Based on the proposed secure protocols, we implement SecureCART in C++ and analyze its performance using three real-world datasets in both LAN and WAN environments. he experimental results indicate that SecureCART is significantly faster than similar schemes proposed in past studies, and that the loss of accuracy while using SecureCART remains within an acceptable range.

关键词： privacy protection decision trees secure multi-party computation secret sharing privileged party

Enhanced service stability and thermoelectric performance in Cu_(2)−δSebased composites

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China Materials 2024年第7期67卷 2369-2370页

作者： Pengfei Qiu Xun Shi State key {1. of High Performance Ceramics and Superfine Microstructure Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050China

Thermoelectric(TE)materials can directly convert the industrial waste heat into useful electricity based on the Seebeck effect,providing a promising way to tackle the environmental pollution and global energy crisis[1..In the past several decades,many new high-performance TE materials have been discovered to enrich the TE *** them,Cu_(2)−δSe-based TE materials,which are in line with the“phonon-liquid electron-crystal”concept,have sparked widespread interest due to the high TE figure-of-merit(ZT)and the combination of elements that are nontoxic and earth-abundant[2].In 201.,Liu et al.[3]reported a ZT of 1.5 at 1.00 K in the stoichiometric Cu_(2)*** alloying S at the Se-site,the ZT was enhanced to around 2.0 at 1.00 K[4].Via incorporating carbon nanotubes,the ZT was further enhanced to 2.4 at 1.00 K[5].Moreover,Yang et al.[6]and Zhou et al.[7]reported that the ZT of Cu_(2)Se/BiCuSeO composites can reach 2.7–2.8 around 1.00 K.

关键词： composites BiCuSeO performance

A Yb optical clock with a lattice power enhancement cavity

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第3期33卷 70-74页

作者：王春云姚远师浩森于洪浮马龙生蒋燕义 State key {1. of Precision Spectroscopy East China Normal UniversityShanghai 200062China

We construct a power enhancement cavity to form an optical lattice in an ytterbium optical *** is demonstrated that the intra-cavity lattice power can be increased by about 45 times,and the trap depth can be as large as 1.00Er when laser light with a power of only 0.6 W incident to the lattice *** high trap depths are the key to accurate evaluation of the lattice-induced light shift with an uncertainty down to~1.*** probing the ytterbium atoms trapped in the power-enhanced optical lattice,we obtain a 4.3 Hz-linewidth Rabi spectrum,which is then used to feedback to the clock laser for the close loop operation of the optical lattice *** evaluate the density shift of the Yb optical lattice clock based on interleaving measurements,which is-0.46(62)*** result is smaller compared to the density shift of our first Yb optical clock without lattice power enhancement cavity mainly due to a larger lattice diameter of 344μm.

关键词： optical atomic clock optical lattice optical cavity Stark shift