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Nanophononic metamaterials induced proximity effect in heat flux regulation

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Frontiers of physics 2024年第2期19卷 149-156页

作者： Jian zhang Haochun zhang gang zhang School of Energy Science and Engineering Harbin Institute of TechnologyHarbin 150001China Institute of High Performance Computing Agency for ScienceTechnology and Research(A*STAR)Singapore 138632Singapore

Recent studies have shown that the construction of nanophononic metamaterials can reduce thermal conductivity without affecting electrical properties,making them promising in many fields of application,such as energy conversion and thermal ***,although extensive studies have been carried out on thermal conductivity reduction in nanophononic metamaterials,the local heat flux characteristic is still *** this work,we construct a heat flux regulator which includes a silicon nanofilm with silicon *** regulator has remarkable heat flux regulation ability,and various impacts on the regulation ability are ***,even in the region without nanopillars,the local heat current is still lower than that in pristine silicon nanofilms,reduced by the neighboring nanopillars through the thermal proximity *** combine the analysis of the phonon participation ratio with the intensity of localized phonon modes to provide a clear *** findings not only provide insights into the mechanisms of heat flux regulation by nanophononic metamaterials,but also will open up new research directions to control local heat flux for a broad range of applications,including heat management,thermoelectric energy conversion,thermal cloak,and thermal concentrator.

关键词： nanophononic metamaterials proximity effect

2-Independent Domination in Trees

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Journal of the Operations Research Society of China 2024年第2期12卷 485-494页

作者： gang zhang Baoyindureng Wu College of Mathematics and System Sciences Xinjiang UniversityUrumqi830046XinjiangChina

A subset D■V(G)in a graph G is a dominating set if every vertex in V(G)I D is adjacent to at least one vertex of S.A subset S■V(G)in a graph G is a 2-independent set if△(G[S])<*** 2-independence numberα2(G)is the order of a largest 2-independent set in ***,a subset D■V(G)in a graph G is a 2-independent dominating set if D is both dominating and *** 2-independent domination number i^(2)(G)is the order of a smallest 2-independent dominating set in *** this paper,we characterize all trees T of order n with i^(2)(T)=n/***,we prove that for any tree T of order n≥2,i^(2)(T)≤2/3α2(T),and this bound is sharp.

关键词： Domination-Independent domination 2-Independent domination:2-Independence.Trees

Color-kinematics duality and dual conformal symmetry for a four-loop form factor in N=4 SYM

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Science China(Physics,Mechanics & Astronomy) 2024年第4期67卷 64-71页

作者： Guanda Lin gang Yang Siyuan zhang CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUCASHangzhou 310024China International Centre for Theoretical Physics Asia-Pacific Beijing/Hangzhou 310024China

We obtain the integrand of full-color four-loop three-point form factor of the stress-tensor supermultiplet in N=4 SYM,based on the color-kinematics(CK)duality and generalized unitarity *** result not only manifests all dual Jacobi relations via CK duality but also contains 133 free *** suggests the constructibility of the form factor at even higher loops via CK *** also find that the planar form factor has a hidden dual conformal symmetry in the lightlike limit of the operator momentum,which is checked up to four loops.

关键词： S-matrix supersymmetric model perturbative calculations

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How to implement a knowledge graph completeness assessment with the guidance of user requirements

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Journal of Systems Engineering and Electronics 2024年第3期35卷 679-688页

作者： zhang Ying XIAO gang Institute of Systems Engineering Academy of Military SciencesBeijing 100107China

In the context of big data, many large-scale knowledge graphs have emerged to effectively organize the explosive growth of web data on the Internet. To select suitable knowledge graphs for use from many knowledge graphs, quality assessment is particularly important. As an important thing of quality assessment, completeness assessment generally refers to the ratio of the current data volume to the total data *** evaluating the completeness of a knowledge graph, it is often necessary to refine the completeness dimension by setting different completeness metrics to produce more complete and understandable evaluation results for the knowledge ***, lack of awareness of requirements is the most problematic quality issue. In the actual evaluation process, the existing completeness metrics need to consider the actual application. Therefore, to accurately recommend suitable knowledge graphs to many users, it is particularly important to develop relevant measurement metrics and formulate measurement schemes for completeness. In this paper, we will first clarify the concept of completeness, establish each metric of completeness, and finally design a measurement proposal for the completeness of knowledge graphs.

关键词： knowledge graph completeness assessment relative completeness user requirement quality management

Phylotranscriptomic discordance is best explained by incomplete lineage sorting within Allium subgenus Cyathophora and thus hemiplasy accounts for interspecific trait transition

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Plant Diversity 2024年第1期46卷 28-38页

作者： Zengzhu zhang gang Liu Minjie Li State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems College of EcologyLanzhou UniversityLanzhou 730000GansuPR China

The transition of traits between genetically related lineages is a fascinating topic that provides clues to understanding the drivers of speciation and *** can be learned about this process from phylogeny-based trait ***,such inference is often plagued by genome-wide gene-tree discordance(GTD),mostly due to incomplete lineage sorting(ILS)and/or introgressive hybridization,especially when the genes underlying the traits appear ***,by collecting transcriptomes,whole chloroplast genomes(cpDNA),and population genetic datasets,we used the coalescent model to turn GTD into a source of information for ILS and employed hemiplasy to explain specific cases of apparent“phylogenetic discordance”between different morphological traits and probable species phylogeny in the Allium *** concatenation and coalescence methods consistently showed the same phylogenetic topology for species tree inference based on single-copy genes(SCGs),as supported by the KS ***,GTD was high across the genomes of ***:~27%e38.9%of the SCG trees were in conflict with the species *** and nuclear incongruence was also *** coalescent simulations indicated that such GTD was mainly a product of *** hemiplasy risk factor calculations supported that random fixation of ancient polymorphisms in different populations during successive speciation events along the *** phylogeny may have caused the character transition,as well as the anomalous cpDNA *** study exemplifies how phylogenetic noise can be transformed into evolutionary information for understanding character state transitions along species phylogenies.

关键词： Hemiplasy Multispecies coalescence Lineage sorting Gene tree discordance Phylotranscriptomics Allium subg.Cyathophora

Metal–Organic Framework‑Based Photodetectors

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Nano-Micro Letters 2024年第11期16卷 675-703页

作者： Jin‑Biao zhang Yi‑Bo Tian Zhi‑gang Gu Jian zhang State Key Laboratory of Structural Chemistry Structure of MatterFujian Institute of ResearchChinese Academy of SciencesFuzhouFujian 350002People’s Republic of China College of Chemistry and Materials Science Fujian Nornal UniversityFuzhou 350007FujianPeople’s Republic of China Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou 350108FujianPeople’s Republic of China University of Chinese Academy of Science Beijing 100049People’s Republic of China

The unique and interesting physical and chemical properties of metal–organic framework(MOF)materials have recently attracted extensive attention in a new generation of photoelectric *** this review,we summarized and discussed the research progress on MOF-based *** methods of preparing MOF-based photodetectors and various types of MOF single crystals and thin film as well as MOF composites are introduced in ***,the photodetectors applications for X-ray,ultraviolet and infrared light,biological detectors,and circularly polarized light photodetectors are ***,summaries and challenges are provided for this important research field.

关键词： Metal-organic frameworks Semiconductor Photodetectors

Diffraction limit of light in curved space

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Photonics Research 2024年第2期12卷 235-243页

作者： JINGXUAN zhang CHENNI XU PATRICK SEBBAH LI-gang WANG School of Physics Zhejiang UniversityHangzhou 310058China Department of Physics The Jack and Pearl Resnick Institute for Advanced TechnologyBar-Ilan UniversityRamat-Gan 5290002Israel

Overcoming the diffraction limit is crucial for obtaining high-resolution images and observing fine *** this conventional difficulty still puzzling us and the prosperous development of wave dynamics of light interacting with gravitational fields in recent years,how spatial curvature affects the diffraction limit is an attractive and important *** we investigate the issue of the diffraction limit and optical resolution on two-dimensional curved space—surfaces of revolution(SORs)with constant or variable spatial *** show that the diffraction limit decreases and the resolution is improved on SORs with positive Gaussian curvature,opening a new avenue to *** diffraction limit is also influenced by the propagation direction,as well as the propagation distance in curved space with variable spatial *** results provide a possible method to control the optical resolution in curved space or equivalent waveguides with varying refractive index distribution and may allow one to detect the presence of the nonuniform strong gravitational effect by probing locally the optical resolution.

关键词： limit curved curvature

General properties of the spectral form factor in open quantum systems

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Frontiers of physics 2024年第3期19卷 229-237页

作者： Yi-Neng Zhou Tian-gang Zhou Pengfei zhang Institute for Advanced Study Tsinghua UniversityBeijing 100084China Department of Physics Fudan UniversityShanghai 200438China

The spectral form factor(SFF)can probe the eigenvalue statistic at different energy scales as its time variable *** closed quantum chaotic systems,the SFF exhibits a universal dip-ramp-plateau behavior,which reflects the spectrum rigidity of the *** this work,we explore the general properties of SFF in open quantum *** find that in open systems the SFF first decays exponentially,followed by a linear increase at some intermediate time scale,and finally decreases to a saturated plateau *** derive general relations between(i)the early-time decay exponent and Lindblad operators;(ii)the long-time plateau value and the number of steady *** also explain the effective field theory perspective of general *** verify our theoretical predictions by numerically simulating the Sachdev−Ye−Kitaev(SYK)model,random matrix theory(RMT),and the Bose−Hubbard model.

关键词： spectral form factor open quantum system quantum chaos

Monitoring of Sweat pH and Dual-Mode Anti-Counterfeiting from Metal-Organic Framework-Based Multifunctional Gel

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Chinese Journal of Chemistry 2024年第5期42卷 491-498页

作者： Xiangnan Wang Hongli zhang Jiahe Li gang Zou Key Laboratory of Precision and Intelligent Chemistry School of Chemistry and Materials ScienceUniversity of Science and Technology of ChinaHefeiAnhui230026 China

Monitoring of sweat pH plays important roles in physiological health,nutritional balance,psychological stress,and sports ***,the combination of functional MOFs with phosphorescent material to acquire the real-time physiological information,as well as the application of dual mode anti-counterfeiting,has seldom been ***,we developed multifunctional gel films based on MOFs and phosphorescent dyes which responded to H+ions and the related mechanism was studied in *** exposure to H+,the composite gel film exhibited decreased fluorescent signal but enhanced room temperature phosphorescence(RTP),which could be utilized for sweat pH sensing through a ***,multifunctional gel films exhibited a potential application in information encryption and anti-counterfeiting by designing of stimulus responsive multiple *** research provided a new avenue for portable and non-invasive sweat pH monitoring methods while also offering insights into stimulus-responsive multifunctional materials.

关键词： Metal–Organic Frameworks Room-temperature phosphorescence Fluorescence Sweat pH monitor Anti-counterfeiting Yttrium Polymer composites Luminescence