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Simulation of magnetization process and Faraday effect of magnetic bilayer films

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Chinese Physics B 2024年第9期33卷 590-597页

作者： Sheng Gao An Du Lei Zhang Tian-Guang Li da-Cheng Ma Department of Basic and General Studies Shenyang Institute of Science and TechnologyShenyang 110167China College of Science Northeastern UniversityShenyang 110819China National Frontiers Science Center for Industrial Intelligence and Systems Optimization Northeastern UniversityShenyang 110819China Office of Academic Research Shenyang Institute of Science and TechnologyShenyang 110167China State Key Laboratory of Robotics Shenyang Institute of AutomationChinese Academy ofSciencesShenyang 110016China Institutes for Robotics and Intelligent Manufacturing Chinese Academy of SciencesShenyang110016China

We described ferromagnetic film and bilayer films composed of two ferromagnetic layers coupled through antiferromagnetic interfacial interaction by classical Heisenberg model and simulated their magnetization state,magnetic permeability,and Faraday effect at zero and finite temperature by using the Landau–Lifshitz–Gilbert(LLG)*** results indicate that in a microwave field with positive circular polarization,the ferromagnetic film has one resonance peak while the bilayer film has two resonance ***,the resonance peak disappears in ferromagnetic film,and only one resonance peak emerges in bilayer film in the negative circularly polarized microwave *** the microwave field’s frequency exceeds the film’s resonance frequency,the Faraday rotation angle of the ferromagnetic film is the greatest,and it decreases when the thickness of the two halves of the bilayer is *** the microwave field’s frequency remains constant,the Faraday rotation angle fluctuates with temperature in the same manner as spontaneous magnetization *** a DC magnetic field is applied in the direction of the anisotropic axis of the film,the Faraday rotation angle varies with the DC magnetic field and shows a similar shape of the hysteresis loop.

关键词： magnetic bilayer films magnetic permeability hysteresis loop Faraday effect Landau–Lifshitz– Gilbert (LLG) equation

Assembly structures of coastal woody species of eastern South America:Patterns and drivers

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Plant Diversity 2024年第5期46卷 611-620页

作者： Eduardo Vinícius da Silva Oliveira Myrna Friederichs Landim Sidney F.Gouveia Graduate Program in Ecology and Conservation Federal University of SergipeSão CristovãoSergipeBrazil National Institute of Science and Technology Ecology Evolution and Conservation of Biodiversity(INCT-EECBio)GoiâniaGoiasBrazil Department of Biology Federal University of SergipeSão CristóvãoSergipeBrazil Department of Ecology Federal University of SergipeSão CristóvãoSergipeBrazil

Tropical regions have provided new insights into how ecological communities are *** dry coastal communities,water stress has been hypothesized to determine plant assembly structure by favoring preadapted lineages from neighboring ecosystems,consistent with functional ***,it is unclear whether this hypothesis is sufficient to explain how coastal communities in tropical ecosystems are ***,we test whether water stress or other factors drive community assembly in woody plant communities across the coastal zone of Brazil,a tropical *** characterized functional and phylogenetic structures of these communities and determined the underlying environmental factors(e.g.,water stress,historical climate stability,edaphic constraints,and habitat heterogeneity)that drive their community *** of coastal woody species show geographically varied patterns,including stochastic arrangements,clustering,and overdispersion of species relative to their traits and phylogenetic *** complexity,water vapor pressure,and soil nutrient availability best explained the gradient in the functional *** deficit,water vapor pressure,and soil organic carbon were the best predictors of variation in phylogenetic *** results support the water-stress conservatism hypothesis on functional and phylogenetic structure,as well as the effect of habitat heterogeneity on functional structure and edaphic constraints on functional and phylogenetic *** effects are associated with increased phenotypic and phylogenetic divergence of woody plant assemblages,which is likely mediated by abiotic filtering and niche opportunities,suggesting a complex pattern of ecological assembly.

关键词： Brazil Completeness Clustering Restinga vegetation Water constraints

Hybrid perovskite shows temperature-dependent photoluminescence and dielectric response triggered by halogen substitution

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Chinese Journal of Structural Chemistry 2024年第6期43卷 28-33页

作者： Xiao-Tong Sun Hao-Fei Ni Yi Zhang da-Wei Fu Ordered Matter Science Research Center Jiangsu Key Laboratory for Science and Applications of Molecular FerroelectricsSoutheast UniversityNanjing211189People's Republic of China Institute for Science and Applications of Molecular Ferroelectrics Key Laboratory of the Ministry of Education for Advanced Catalysis MaterialsZhejiang Normal UniversityJinhua321004People's Republic of China

Materials exhibiting dielectric switching response and photoluminescence(PL)are promising for sensors and information *** previous research,we synthesized a series of materials with red or green PL and dielectric switching capabilities by incorporating luminescent metal halides into organic ammonium ***,effective modification to synthesize organic-inorganic hybrid materials with dielectric switching response and orange PL continues to be a challenge in the respective *** PL materials are valuable for switching and sensors,and most orange light sources are derived from rare earth elements,making them harder to *** have successfully synthesized two organic-inorganic hybrid materials([CMPD]PbBr_(3)(1)and[BMPD]PbBr_(3)(2),CMPD=N-ClCH_(2)-N-methylpiperidine,BMPD=N-BrCH_(2)-N-methylpiperidine)that exhibit both orange PL and dielectric switching *** Cl in compound 1 is substituted by Br in compound 2,the phase transition temperature of the compound is elevated by 45 *** compounds exhibit captivating orange light emission when exposed to ultraviolet *** research provides insights into exploring multifunctional materials with orange PL and dielectric switching response and provides proof for halogen substitution strategies to design materials with higher phase transition temperatures.

关键词： Dielectric switching Photoluminescence Orange

Application of ^(18)F-fluorodeoxyglucose positron emission tomography/computed tomography imaging in recurrent anastomotic tumors after surgery in digestive tract tumors

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World Journal of Gastrointestinal Surgery 2024年第8期16卷 2474-2483页

作者： Deng-Feng Ge Hao Ren Zi-Chen Yang Shou-Xiang Zhao Zhen-Ting Cheng da-da Wu Bin Zhang Department of Cardiothoracic Surgery Nanjing University of Chinese MedicineNanjing 210023Jiangsu ProvinceChina Department of Gastrointestinal Surgery Shanghai Sixth People’s HospitalShanghai 250063China

BACKGROUND This study was to investigate the application value of whole-body dynamic ^(18)F-fluorodeoxyglucose(FDG)positron emission tomography/computed tomogra-phy(PET/CT)imaging in recurrent anastomotic tumors of digestive tract after gastric and esophageal cancer *** patients with gastric and esophageal cancer have a high risk of tumor recurrence,and traditional imaging methods have certain limitations in early detection of recurrent ***-body dynamic ^(18)F-FDG PET/CT imaging,due to its high sensitivity and specifi-city,can provide comprehensive information on tumor metabolic activity,which is expected to improve the early diagnosis rate of postoperative recurrent tumors,and provide an important reference for clinical treatment *** A retrospective analysis was performed on 53 patients with upper digestive tract tumors after operation and systemic dynamic ^(18)F-FDG PET/CT imaging indi-cating abnormal FDG uptake by anastomosis,including 29 cases of gastric cancer and 24 cases of esophageal *** to the follow-up results of gas-troscopy and other imaging examinations before and after PET/CT examination,the patients were divided into an anastomotic recurrence group and anastomotic inflammation *** multi-parameter analysis software was used to obtain the metabolic rate(MRFDG),volume of distribution maximum(DVmax)of anastomotic lesions,and MRmean and DVmean of normal liver *** lesion/background ratio(LBR)was calculated by dividing the MRFDG and DVmax of the anastomotic lesion by the MRmean and DVmean of the normal liver tissue,respectively,to obtain LBR-MRFDG and *** independent sample t test was used for statistical analysis,and a receiver operating characteristic curve was used to analyze the differential diagnostic efficacy of each parameter for anastomotic recurrence and *** The dynamic ^(18)F-FDG PET/CT imaging parameters MRFDG,DVmax,LBR-MRFDG,and LBR-DVmax of post

关键词： Gastric cancer Esophageal cancer Anastomosis Dynamic positron emission tomography Differential diagnosis Metabolic rate

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超大城市空间重构中的“村政城治”

甘肃社会科学 2024年第3期 107-115页

作者：姚尚建华东政法大学政府管理学院上海201620

超大城市的规模扩张意味着广域范围的城市乡村的联动发展。在这一空间重构过程中,城乡关系的分野被忽视了,超大城市借助于交通、项目甚至新城建设“侵入”乡村,从而模糊了城乡边界。随着新城直接面向乡村治理,超大城市实现了“乡政村治... 详细信息

超大城市的规模扩张意味着广域范围的城市乡村的联动发展。在这一空间重构过程中,城乡关系的分野被忽视了,超大城市借助于交通、项目甚至新城建设“侵入”乡村,从而模糊了城乡边界。随着新城直接面向乡村治理,超大城市实现了“乡政村治”向“村政城治”的逻辑转换。在这一过程中,超大城市通过织密权力网络、集中居住等政策强化城市在地性公共服务对于乡村治理的引领,但是这一思路又强化了村庄对于超大城市的依附。超大城市的乡村振兴需要承认城乡关系的历时性特征,系统反思新城建设、乡村发展中的空间、产业与人口关系联动,通过政策均衡实现超大城市生态、生产、生活功能的内在契合。

关键词：城市治理超大城市城乡关系三生空间村政城治

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论中国古籍钤印的分类

文献 2024年第5期 80-109页

作者：莫俊暨南大学图书馆

目前古籍钤印分类研究中存在对钤印概念的内涵和外延理解不准确,对钤印类型的多样化和复杂性认识不充分,对钤印分类依据、方法的规范性和科学性把握不恰当等不足。解决上述不足,可以“古籍钤印”作为顶层概念,在借鉴既有分类成果并占有... 详细信息

目前古籍钤印分类研究中存在对钤印概念的内涵和外延理解不准确,对钤印类型的多样化和复杂性认识不充分,对钤印分类依据、方法的规范性和科学性把握不恰当等不足。解决上述不足,可以“古籍钤印”作为顶层概念,在借鉴既有分类成果并占有更多材料的基础上,以功能为分类依据,将古籍钤印分为出版印、流传印两大类目,分别包含若干下位分类,从语义、语法、语用等角度就类目的概念、印文内容及印文组织形式进行综合剖析,重新构建种类涵盖广泛、类目设计合理、层级关系分明的古籍钤印分类体系,推动新时期古籍钤印整理研究工作的深入。

关键词：古籍钤印分类出版藏书

Hyperbolic hierarchical graph attention network for knowledge graph completion

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High Technology Letters 2024年第3期30卷 271-279页

作者： XU Hao CHEN Shudong QI Donglin TONG da YU Yong CHEN Shuai Institute of Microelectronics of Chinese Academy of Sciences Beijing 100029P.R.China University of Chinese Academy of Sciences Beijing 100049P.R.China

Utilizing graph neural networks for knowledge embedding to accomplish the task of knowledge graph completion(KGC)has become an important research area in knowledge graph ***,the number of nodes in the knowledge graph increases exponentially with the depth of the tree,whereas the distances of nodes in Euclidean space are second-order polynomial distances,whereby knowledge embedding using graph neural networks in Euclidean space will not represent the distances between nodes *** paper introduces a novel approach called hyperbolic hierarchical graph attention network(H2GAT)to rectify this ***,the paper conducts knowledge representation in the hyperbolic space,effectively mitigating the issue of exponential growth of nodes with tree depth and consequent information ***,it introduces a hierarchical graph atten-tion mechanism specifically designed for the hyperbolic space,allowing for enhanced capture of the network structure inherent in the knowledge ***,the efficacy of the proposed H2GAT model is evaluated on benchmark datasets,namely WN18RR and FB15K-237,thereby validating its *** H2GAT model achieved 0.445,0.515,and 0.586 in the Hits@1,Hits@3 and Hits@10 metrics respectively on the WN18RR dataset and 0.243,0.367 and 0.518 on the FB15K-237 *** incorporating hyperbolic space embedding and hierarchical graph attention,the H2GAT model successfully addresses the limitations of existing hyperbolic knowledge embedding models,exhibiting its competence in knowledge graph completion tasks.

关键词： hyperbolic space link prediction knowledge graph embedding knowledge graph completion(KGC)

Understanding the Thermal Impedance of Silicone Rubber/Hexagonal Boron Nitride Composites as Thermal Interface Materials

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Chinese Journal of Polymer Science 2024年第3期42卷 352-363,I0008页

作者： Yuan Ji Shi-da Han Hong Wu Shao-Yun Guo Feng-Shun Zhang Jian-Hui Qiu The State Key Laboratory of Polymer Materials Engineering Sichuan Provincial Engineering Laboratory of Plastic/Rubber Complex Processing TechnologyPolymer Research InstituteSichuan UniversityChengdu 610065China Institute of Chemical Materials China Academy of Engineering PhysicsMianyang 621900China Department of Mechanical Engineering Faculty of Systems Science and TechnologyAkita Prefectural UniversityAkita 015-0055Japan

Silicone rubber(SR) composites are most widely used as thermal interface materials(TIMs) for electronics heat dissipation. Thermal impedance as the main bottleneck limiting the performance of TIMs is usually neglected. Herein, the thermal impedance of SR composites loaded with different levels of hexagonal boron nitride(h-BN) as TIMs was elaborated for the first time by the ASTM D 5470 standard test and finite element analysis. It was found that elastic modulus and surface roughness of SR composites increased with the increase of h-BN content, indicating that the conformity was reduced. When the assembly pressure was 0.69 MPa, there existed an optimal h-BN content at which the contact resistance was minimum(0.39 K·cm^(2)·W^(-1)). Although the decreased bond line thickness(BLT) by increasing the assembly pressure was beneficial to reduce the thermal impedance, the proper assembly pressure should be selected to prevent the warpage of the contact surfaces and the increase in contact resistance, according to the compression properties of the SR composites. This study provides valuable insights into fabrication of high-performance TIMs for modern electronic device applications.

关键词： Thermal interface materials Hexagonal boron nitride Thermal impedance Surfaces

data-driven casting defect prediction model for sand casting based on random forest classification algorithm

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China Foundry 2024年第2期21卷 137-146页

作者： Bang Guan Dong-hong Wang da Shu Shou-qin Zhu Xiao-yuan Ji Bao-de Sun Shanghai Key Lab of Advanced High-Temperature Materials and Precision Forming School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China State Key Lab of Metal Matrix Composites Shanghai Jiao Tong UniversityShanghai 200240China Hefei Casting and Forging Factory of Anhui Heli Co. LtdHefei 230000China State Key Laboratory of Materials Processing and Die&Mould Technology Huazhong University of Science and TechnologyWuhan 430074China

The complex sand-casting process combined with the interactions between process parameters makes it difficult to control the casting quality,resulting in a high scrap rate.A strategy based on a data-driven model was proposed to reduce casting defects and improve production efficiency,which includes the random forest(RF)classification model,the feature importance analysis,and the process parameters optimization with Monte Carlo *** collected data includes four types of defects and corresponding process parameters were used to construct the RF *** results show a recall rate above 90% for all *** Gini Index was used to assess the importance of the process parameters in the formation of various defects in the RF ***,the classification model was applied to different production conditions for quality *** the case of process parameters optimization for gas porosity defects,this model serves as an experimental process in the Monte Carlo method to estimate a better temperature *** prediction model,when applied to the factory,greatly improved the efficiency of defect *** show that the scrap rate decreased from 10.16% to 6.68%.

关键词： sand casting process data-driven method classification model quality prediction feature importance