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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

A comparative study on mechanical and vibroacoustic performance of sandwich cylindrical shells with positive,negative,and zero Poisson’s ratio cellular cores

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Journal of Ocean Engineering and Science 2024年第4期9卷 379-390页

作者： Qing li Peichang li Yongjin guo Xi’an liu State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghai200240China China Ship Development and Design Center Wuhan430064China MOE Key Laboratory of Marine Intelligent Equipment and System Shanghai Jiao Tong UniversityShanghai200240China

Deep-sea submersibles are significant mobile platforms requiring multi-functional capabilities that are strongly determined by the constituent *** cylindrical protective cover can be advanced by designing their sandwiched cellular materials whose physical properties can be readily parameterized and flexibly *** honeycomb materials are capable of possessing tuned positive,negative,or zero Poisson’s ratios(PPR,NPR,and ZPR),which is expected to produce distinct physical performance when utilized as a cellular core of cylindrical shells for the deep-sea submersibles.A novel cylindrical meta-structure sandwiched with the semi-re-entrant ZPR metamaterial has been designed as well as its similarly-shaped sandwich cylindrical shell structures with PPR and NPR *** mechanical and vibroacoustic performance of sandwich cylindrical shells with cellular materials featuring a full characteristic range of Poisson’s ratios are then compared systematically to explore their potential for engineering applications on submerged pressure-resistant *** respective unit cells are designed to feature an equivalent load-bearing *** properties of pressure resistance,buckling,and sound insulation are simulated,respectively,and the orders of each property are then generalized by systematic *** results indicate that the PPR honeycomb core takes advantage of higher structural strength and stability while the ZPR one yields better energy absorption and sound insulation *** NPR one yields moderate properties and has the potential for lower circumferential *** work explores the application of cellular materials with varied Poisson’s ratios and provides guidance for the multi-functional design of sandwich cylindrical meta-structures.

关键词： Sandwich cylindrical shells Poisson’s ratio Pressure-resistant Buckling Vibroacoustic

The competition between Bidens pilosa and Setaria viridis alters soil microbial composition and soil ecological function

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Journal of Integrative Agriculture 2024年第1期23卷 267-282页

作者： Qiao li Jianying guo Han Zhang Mengxin Zhao State Key Laboratory for Biology of Plant Diseases and Insect Pests Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijing 100193China College of life Science Yangtze UniversityJingzhou 434025China

Bidens pilosa is recognized as one of the major invasive plants in *** invasion has been associated with significant losses in agriculture,forestry,husbandry,and *** ecosystems play an important role in alien plant *** within the soil act as intermediaries between plants and soil ecological functions,playing a role in regulating soil enzyme activities and nutrient *** the interactions between invasive plants,soil microorganisms,and soil ecological processes is vital for managing and mitigating the impacts of invasive species on the *** this study,we conducted a systematic analysis focusing on *** and Setaria viridis,a common native companion plant in the invaded *** simulate the invasion process of ***,we constructed homogeneous plots consisting of *** and *** grown separately as monocultures,as well as in *** rhizosphere and bulk soils were collected from the alien plant *** and the native plant *** order to focus on the soil ecological functional mechanisms that contribute to the successful invasion of ***,we analyzed the effects of *** on the composition of soil microbial communities and soil ecological *** results showed that the biomass of *** increased by 27.51% and that of *** was significantly reduced by 66.56%.The organic matter contents in the bulk and rhizosphere soils of *** were approximately 1.30 times those in the native plant *** TN and NO_(3)^(-)contents in the rhizosphere soil of *** were 1.30 to 2.71 times those in the native plant *** activities of acid phosphatase,alkaline phosphatase,and urease in the rhizosphere soil of *** were 1.98-2.25 times higher than in the native plant *** high-throughput sequencing of the16S rRNA gene,we found that *** altered the composition of the soil microbial ***,many genera in Actinobacteria and Proteobacteri

关键词： plant invasion Bidens pilosa soil microbial composition soil properties soil enzyme activities

Weighted Composition Operators That Preserve Frames On Weighted Hardy Spaces

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Acta Mathematica Sinica,English Series 2024年第7期40卷 1645-1654页

作者： Ya li Dong Rui liu guo Xiang Lu School of Mathematical Sciences and LPMC Nankai UniversityTianjin300071P.R.China School of Statistics and Mathematics Zhongnan University of Economics and LawWuhan430073P.R.China

In this paper, we characterize weighted composition operators that preserve frames on the weighted Hardy spaces in the unit disk. In particular, we obtain the symbol properties of the bounded invertible weighted composition operators. Moreover, we establish the equivalence between bounded invertible operators and frame-preserving operators. Furthermore, we show that weighted composition operator preserves frames if and only if it preserves the Riesz bases property. Additionally,we investigate the weighted composition operators that preserve tight or normalized tight frames on the Dirichlet space.

关键词： Weighted composition operators Weighted Hardy spaces frames invertible

Swelling pressure evolution characterization of strong expansive soil considering the influence of reserved expansion deformation

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Journal of Mountain Science 2024年第1期21卷 252-270页

作者： li Tianguo KONG lingwei guo Aiguo YAN Junbiao State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan 430071China University of Chinese Academy of Sciences Beijing 100049China

Numerous engineering cases have demonstrated that the expansive soil channel slope remains susceptible to damage with the implementation of a rigid or closed protective structure. It is common for the protective structure to experience bulging failure due to excessive swelling pressure. To investigate the swelling pressure properties of expansive soil, the constant volume test was employed to study the influence of water content and reserved expansion deformation on the characteristics of swelling pressure in strong expansive soils, and also to explore the evolution mechanism of the swelling pressure. The findings demonstrate that the swelling pressure-time curve can be classified into swelling pressure-time softening and swelling pressure-time stability type. The swelling pressuretime curve of the specimen with low water content is the swelling pressure-time softening type, and the softening level will be weakened with increasing reserved expansion deformation. Besides, the maximum swelling pressure Psmax decreases with increasing water content and reserved expansion deformation, especially for expansion ratio η from 24% to 37%. The reserved deformation has little effect on reducing Psmax when it is beyond 7% of the expansion rate. The specimen with low water content has a more homogeneous structure due to the significant expansion-filling effect, and the fracture and reorganization of the aggregates in the specimens with low water content cause the swelling pressure-time softening behavior. In addition, the proposed swelling pressure-time curve prediction model has a good prediction on the test results. If necessary, a deformation space of about 7% expansion rate is recommended to be reserved in the engineering to reduce the swelling pressure except for keeping a stable water content.

关键词： Expansive soil Swelling pressure Reserved expansion deformation Water content

Mechanical Behavior Based on Aggregates Microstructure of Ultra-high Performance Concrete

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Journal of Wuhan University of Technology(Materials Science) 2024年第3期39卷 673-681页

作者：丁庆军 ZHOU Changsheng 张高展 guo Hong li Yang ZHANG Yongyuan guo Kaizheng School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China Advanced Building Materials Key Laboratory of Anhui Province School of Material Science and Chemical EngineeringAnhui Jianzhu UniversityHefei 230601China China Railway 17th Bureau Group Co. Ltd.Taiyuan 030006China

We developed ultra-high performance concrete(UHPC)incorporating mullite sand and brown corundum sand(BCS),and the quartz sand UHPC was utilized to prepare for *** properties of compressive strength,elastic modulus,ultrasonic pulse velocity,flexural strength,and toughness were *** electron microscopy and nanoindentation were also conducted to reveal the underlying mechanisms affecting macroscopic *** to the superior interface bonding properties between mullite sand and matrix,the compressive strength and flexural toughness of UHPC have been significantly *** sand and BCS aggregates have higher stiffness than quartz sand,contributing to the excellent elastic modulus exhibited by *** stiffness and volume of aggregates have a more significant impact on the elastic modulus of UHPC than interface performance,and the latter contributes more to the strength of *** study will provide a reference for developing UHPC with superior elastic modulus for structural engineering.

关键词： ultra-high performance concrete mechanical properties fine aggregates microstructure nanoindentation

Ergodicity of 3D Stochastic Burgers Equation

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Acta Mathematica Sinica,English Series 2024年第2期40卷 498-510页

作者： Zhao DONG Jiang Lun WU guo li ZHOU RCSDS Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190P.R.China Department of Mathematics Computational FoundrySwansea UniversitySwansea SA18ENUK College of Mathematics and Statistics Chongqing UniversityChongqing 400044P.R.China

3D Burgers equation is an important model for *** is natural to expect the long-time behaviour for this hydrodynamics ***,there is no result about the long-time behaviour for this deterministic ***,if the system is perturbed by stochastic noise,we establish the existence and uniqueness of invariant measure for 3D stochastic Burgers equation.

关键词： 3D stochastic Burgers equations maximum principle ergodicity

Noise Effect on the 2D Stochastic Burgers Equation

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Acta Mathematica Sinica,English Series 2024年第9期40卷 2065-2090页

作者： Zhao DONG Jiang Lun WU guo li ZHOU RCSDS Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190P.R.China Beijing Normal University-Hong Kong Baptist University United International College Zhuhai 519087P.R.China Guangdong Provincial Key Laboratory of Interdisciplinary Research and Application for Data Science(IRADS) UICZhuhai 519087P.R.China School of Statistics and Mathematics Chongqing University Key Laboratory of Nonlinear Analysis and Its Applications(Chongqing University) Ministry of EducationChongqing 400044P.R.China

By comprehensive utilizing of the geometry structure of 2D Burgers equation and the stochastic noise,we find the decay properties of the solution to the stochastic 2D Burgers equation with Dirichlet boundary ***,the e... 详细信息

关键词： 2D stochastic Burgers equation regularity

A Practical Approach for Missing Wireless Sensor Networks Data Recovery

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China Communications 2024年第5期21卷 202-217页

作者： Song Xiaoxiang guo Yan li Ning Ren Bing The College of Communications Engineering Army Engineering University of PLANanjing 210007China The 63891 Unit of PLA Luoyang 471000China

In wireless sensor networks(WSNs),the performance of related applications is highly dependent on the quality of data ***,missing data is almost inevitable in the process of data acquisition and *** methods often rely on prior information such as low-rank characteristics or spatiotemporal correlation when recovering missing WSNs ***,in realistic application scenarios,it is very difficult to obtain these prior information from incomplete data ***,we aim to recover the missing WSNs data effectively while getting rid of the perplexity of prior *** designing the corresponding measurement matrix that can capture the position of missing data and sparse representation matrix,a compressive sensing(CS)based missing data recovery model is ***,we design a comparison standard to select the best sparse representation basis and introduce average cross-correlation to examine the rationality of the established ***,an improved fast matching pursuit algorithm is proposed to solve the *** results show that the proposed method can effectively recover the missing WSNs data.

关键词： average cross correlation matching pursuit missing data wireless sensor networks

Gestational diabetes mellitus combined with fulminant type 1 diabetes mellitus, four cases of double diabetes: A case report

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World Journal of Clinical Cases 2024年第4期12卷 787-794页

作者： Hui li yun Chai Wei-Hong guo Yu-Meng Huang Xiao-Na Zhang Wen-li Feng Qing He Jin Cui Ming liu Department of Endocrinology and Metabolism Tianjin Medical University General HospitalTianjin 300052China

BACKGROUND Fulminant type 1 diabetes mellitus(FT1DM)that occurs during pregnancy or the perinatal period is known as pregnancy-related FT1DM(PF),always without history of abnormal glucose ***,we present four patients who developed FT1DM during treatment but were first diagnosed with gestational diabetes mellitus(GDM).CASE SUMMARY The clinical data of four patients with GDM combined with FT1DM admitted to our hospital between July 2018 and April 2021 were collected,and the patients and their infants were followed *** patients were diagnosed with GDM during the second trimester and were *** blood glucose level elevated suddenly during the third trimester and then were diagnosed with *** patients had an insulin allergy,and two had symptoms of upper respiratory tract infection before *** patient developed ketoacidosis,and three developed *** patients had cesarean section deliveries,and two had vaginal *** growth and development of the infants were normal.C-peptide levels were lower than those at onset,suggesting progressive impairment of islet *** frequencies of the DRB109:01,DQB103:03,DQA103:02,DPA101:03,DPA102:02,DPB105:01,DRB401:03,G 01:01,and G 01:04 human leukocyte antigen(HLA)-G alleles were high in the present *** In comparison with pregnancy-associated FT1DM(PF),patients with GDM combined with FT1DM had an older age of onset,higher body mass index,slower onset,fewer prodromal symptoms,and less *** pathogenesis may be due to various factors affecting the already fragileβ-cells of GDM patients with genetically susceptible class II HLA *** speculate that GDM combined with FT1DM during pregnancy,referred to as“double diabetes,”is a subtype of PF with its own unique characteristics that should be investigated further.

关键词： Fulminant type 1 diabetes mellitus Gestational diabetes mellitus Pregnancy-related fulminant type 1 diabetes mellitus Double diabetes Case report