检索结果-南通市图书馆

Sparse Modal Decomposition Method Addressing Underdetermined Vortex-Induced Vibration Reconstruction Problem for Marine Risers

在线全文

学校读者我要写书评

暂无评论

China Ocean Engineering 2024年第2期38卷 285-296页

作者： DU Zun-feng ZHU Hai-ming yu Jian-xing State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation School of Civil EngineeringTianjin UniversityTianjin 300350China

When investigating the vortex-induced vibration(VIV)of marine risers,extrapolating the dynamic response on the entire length based on limited sensor measurements is a crucial step in both laboratory experiments and fatigue monitoring of real *** problem is conventionally solved using the modal decomposition method,based on the principle that the response can be approximated by a weighted sum of limited vibration ***,the method is not valid when the problem is underdetermined,i.e.,the number of unknown mode weights is more than the number of known *** study proposed a sparse modal decomposition method based on the compressed sensing theory and the Compressive Sampling Matching Pursuit(Co Sa MP)algorithm,exploiting the sparsity of VIV in the modal *** the validation study based on high-order VIV experiment data,the proposed method successfully reconstructed the response using only seven acceleration measurements when the conventional methods failed.A primary advantage of the proposed method is that it offers a completely data-driven approach for the underdetermined VIV reconstruction problem,which is more favorable than existing model-dependent solutions for many practical applications such as riser structural health monitoring.

关键词： motion reconstruction vortex-induced vibration(VIV) marine riser modal decomposition method compressed sensing

The impacts of gradually terminating nonpharmaceutical interventions for SARS-CoV-2:A mathematical modelling analysis

在线全文

学校读者我要写书评

暂无评论

Fundamental Research 2024年第2期4卷 401-411页

作者： Bin Wu yuetian yu xing Lin feng Medical Decision and Economic Group Department of PharmacyRen Ji HospitalSouth CampusSchool of MedicineShanghai Jiaotong UniversityShanghai 200000China Department of Critical Care Medicine Ren Ji HospitalSchool of MedicineShanghai Jiaotong UniversityShanghai 200001China Department of Health Policy and Management School of Public HealthPeking UniversityBeijing 100191China

With the expansion of vaccination programs,the policy of terminating nonpharmaceutical interventions for preventing the SARS-CoV-2 pandemic should become more *** current study investigated the clinical and economic outcomes of intervention policies combining nonpharmaceutical interventions and vaccination programs for dealing with the SARS-CoV-2 *** agent-based transmission model was adopted that describes how a SARS-CoV-2 virus spreads in the populations of *** model inputs were derived from the literature and expert *** following intervention policies were simulated:no intervention,strict nonpharmaceutical interventions,and nonpharmaceutical interventions for workplace,community,school and home gradually terminated by combining vaccination programs for specified age groups(vaccination age in years:20-60,20-70,20-80,≥20,≥10 and whole population).Cumulative infections and deaths in one calendar year,costs and quality-adjusted life years(QALYs)were *** the vaccination program was taken up in at least the≥20 years age group in all populations,nonpharmaceutical interventions for workplace and community settings could be gradually terminated because the cumulative number of infections was<100 per 100,000 *** ending nonpharmaceutical interventions in school and home settings could not meet the target even when the vaccination program had been taken up in all *** cumulative deaths were used as the endpoint,nonpharmaceutical interventions in workplace,community and school settings could be gradually *** efficacy and coverage have substantial *** nonpharmaceutical interventions in workplace settings could produce the lowest cost when vaccination programs are taken up at least in the≥10 years age group;this method dominates most intervention strategies due to its lower costs and higher *** to our findings,nonpharmaceutical interventions might be gradually terminated

关键词： SARS-CoV-2 Nonpharmaceutical interventions Vaccination program Cumulative infections and deaths Economic outcomes

The Complete Classification of Graphs whose Second Largest Eigenvalue of the Eccentricity Matrix is Less Than 1

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

Acta Mathematica Sinica,English Series 2024年第7期40卷 1741-1766页

作者： Jian feng WANG xing yu LEI Shu Chao LI Zoran STANIC School of Mathematics and Statistics Shandong University of TechnologyZibo255049P.R.China Faculty of Mathematics and Statistics Central China Normal UniversityWuhan430079P.R.China Faculty of Mathematics University of BelgradeStudentski trg 1611000BelgradeSerbia

The eccentricity matrix of a graph is obtained from the distance matrix by keeping the entries that are largest in their row or column,and replacing the remaining entries by *** matrix can be interpreted as an opposite to the adjacency matrix,which is on the contrary obtained from the distance matrix by keeping only the entries equal to *** the paper,we determine graphs having the second largest eigenvalue of eccentricity matrix less than 1.

关键词： Eccentricity matrix eigenvalue diameter principal submatrix forbidden subgraph

Nitrogen-doped titanium dioxide/schwertmannite nanocomposites as heterogeneous photo-Fenton catalysts with enhanced efficiency for the degradation of bisphenol A

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第9期143卷 1-11页

作者： xing-xing Qiao yu-Hang Xu Xiang-Ji Liu Sai-Le Chen Zhou Zhong Ya-feng Li Jian Lü Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation College of Resources and EnvironmentFujian Agriculture and Forestry UniversityFuzhou 350002China State Key Laboratory of Photocatalysis on Energy and Environment Fuzhou UniversityFuzhou 350116China

Potential health risks related to environmental endocrine disruptors(EEDs)have aroused research hotspots at the forefront of water treatment ***,nitrogen-doped titanium dioxide/schwertmannite nanocomposites(N-TiO_(2)/SCH)have been successfully developed as heterogeneous catalysts for the degradation of typical EEDs via photo-Fenton *** to the sustainable Fe(Ⅲ)/Fe(Ⅱ)conversion induced by photoelectrons,as-prepared N-TiO_(2)/SCH nanocomposites exhibit much enhanced efficiency for the degradation of bisphenol A(BPA;ca.100% within 60 min under visible irradiation)in a wide pH range of 3.0-7.8,which is significantly higher than that of the pristine schwertmannite(ca.74.5%)or N-TiO_(2)(ca.10.8%).In this photo-Fenton system,the efficient degradation of BPA is mainly attributed to the oxidation by hydroxyl radical(·OH)and singlet oxygen(^(1)O_(2)).Moreover,the possible catalytic mechanisms and reaction pathway of BPA degradation are systematically investigated based on analytical and photoelectrochemical *** work not only provides a feasible means for the development of novel heterogeneous photo-Fenton catalysts,but also lays a theoretical foundation for the potential application of mineral-based materials in wastewater treatment.

关键词： Titanium dioxide Schwertmannite Fenton reaction Environmental endocrine disruptors Photocatalysis

Concerted Steric and Electronic Strategy in Thermostable Salicylaldiminato Nickel Catalysts for Ethylene(Co)polymerization

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第8期42卷 1085-1092页

作者： Hong-yu Ji Hong-Liang Mu Chun-feng Tang yu-xing Zhang yue Chi Zhong-Bao Jian Key Laboratory of Advanced Structural Materials Ministry of EducationSchool of Materials Science and EngineeringChangchun University of TechnologyChangchun 130012China State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China

Olefin polymerization is one of the most im portant chemical reactions in *** work presents a strategy that emphasizes the synergistic meta/poro-steric hindrance of N-aryl groups and electronic effects in newly synthesized neutral salicylaldiminato nickel *** nickel(Ⅱ)catalysts exhibit exceptional thermostability,ranging from 30℃to 130℃,demonstrating enhanced catalytic activities and broadly regulated polyethylene molecular weights(3-341 kg·mol^(-1))and controlled polymer branch density(2-102 brs/1000C).The preferred catalyst Ni3 with concerted steric and electronic effects enables the production of solid-state semi-crystalline polyethylene materials at temperatures below 90℃.Notably,Ni3 exhibits an impressive tolerance of 110℃and can withstand even the challenging polymerization temperature of 130℃,leading to the production of polyethylene wax and ***,functionalized polyethylene is produced.

关键词： Polyolefin Salicylaldiminato ligand Nickel catalyst Oil Wax

Strain-enhanced polarization sensitivity inβ-Ga_(2)O_(3)photodetector

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4期67卷 126-137页

作者： Yonghui Zhang Huili Liang Fei xing Qiqian Gao yu feng yuping Sun Zengxia Mei School of Physics and Optoelectronic Engineering Shandong University of TechnologyZibo 255000China Songshan Lake Materials Laboratory Dongguan 523808China Institute of Physics Chinese Academy of SciencesBeijing 100190China

Polarization-sensitive photodetection and imaging have great application value in fields such as polarization division multiplexing optical communication,remote sensing,near-field imaging and military *** a high polarization ratio has always been the research hotspot in polarization-sensitive *** this paper,we report a compression strain enhanced polarization ratio inβ-gallium oxide(β-Ga_(2)O_(3))single crystal flake.A rigorous crystallographic analysis confirmed its high crystalline quality and ***-resolved polarization Raman spectroscopy(ARPRS)was adopted to study the anisotropy of its optical *** ARPRS measurements and theoretical calculation consistently demonstrate the strong optical anisotropy in the high-qualityβ-Ga_(2)O_(3)flake.A polarization ratio of 0.96 was obtained in the flatβ-Ga_(2)O_(3)***,mechanical strain of±0.7%was introduced intoβ-Ga_(2)O_(3).An increased polarization ratio of 0.98 was achieved in the case of 0.7%compression strain,which is,to the best of our knowledge,the highest value for UVC polarization-sensitive *** corresponds to an improved polarization rejection ratio of *** work proposed a new path towards improving polarization sensitivity by applying strain engineering in the active material.

关键词： gallium oxide polarization photodetector anisotropy strain

Numerical simulation study on the hygrothermal performance of building exterior walls under dynamic wind-driven rain condition

在线全文

学校读者我要写书评

暂无评论

Building Simulation 2024年第2期17卷 207-221页

作者： xing Hu Huibo Zhang Hui yu School of Design Shanghai Jiao Tong UniversityShanghai200240China

Wind-driven rain(WDR)has a significant influence on the hygrothermal performance,durability,and energy consumption of building *** calculation of WDR loads using semi-empirical models has been incorporated into the boundary conditions of coupled heat and moisture transfer ***,prior research often relied on fixed WDR absorption ratio,which fail to accurately capture the water absorption characteristics of porous building materials under rainfall ***,this study aims to investigate the coupled heat and moisture transfer of exterior walls under dynamic WDR boundary conditions,utilizing an empirically obtained WDR absorption ratio model based on field *** developed coupled heat and moisture transfer model is validated against the HAMSTAD *** findings reveal that the total WDR flux calculated with the dynamic WDR boundary is lower than that obtained with the fixed WDR boundary,with greater disparities observed in orientations experiencing higher WDR *** variations in moisture flow significantly impact the surface temperature and relative humidity of the walls,influencing the calculation of cooling and heating loads by different *** to the transient heat transfer model,the coupled heat and moisture transfer model incorporating dynamic WDR boundary exhibits maximum increases of 17.6%and 16.2%in cooling and heating loads,*** dynamic WDR boundary conditions provide more precise numerical values for surface moisture flux,offering valuable insights for the thermal design of building enclosures and load calculations for HVAC systems.

关键词： wind-driven rain building component hygrothermal model transient simulation cooling and heating loads

Elaborating strengthen mechanism of Pt-Ir solid solution superalloy at finite temperature

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3期43卷 1243-1256页

作者： Wei yu Xiao-yu Chong yun-Xuan Zhou Meng-Di Gan Ying-Xue Liang Yan Wei Ai-Min Zhang Chang-Yi Hu xing-yu Gao Li Chen Hai-feng Song Jing feng Faculty of Materials Science and Engineering Kunming University of Science and TechnologyKunming650093China yunnan Precious Metals Laboratory Co.LTD Kunming650106China Laboratory of Computational Physics Institute of Applied Physics and Computational MathematicsBeijing100088China

Pt-Ir alloy is potential superalloys used above 1300℃because of their high strength and creep ***,the ductility of Pt-Ir alloy has rapidly deteriorated with the increase of Ir,resulting in poor *** work quantitatively evaluated the solid solution strengthening(SSS)and grain refinement strengthening(GRS)of Pt-Ir alloy using first-principles calculations combined with experimental ***,the stretching force constants in the second nearest neighbor region(SFC^(2nd))of pure Ir(193.7 eV·nm^(-2))are 3.40 times that of pure Pt(57.0 eV·nm^(-2)),i.e.,the interatomic interaction is greatly enhanced with the increase of Ir content,which leads to the decrease of ductility,and modulus misfit plays a dominant role in ***,the physical mechanisms responsible for the hardness(H_(V))of Pt-Ir alloy,using the power-law-scaled function of electron work function coupled SSS and GRS,are attributed to the electron redistribution caused by different Ir ***,a thorough assessment of the thermodynamic characteristics of Pt-Ir binary alloy was conducted,culminating in development of a mapping model that effectively relates enmposition,temperature and *** results revealed that the compressive strength incrcases with the Ir content,and the highest strength was observed in Pt_(0.25)Ir_(0.75).This study provides valuable insights into the Pt-Ir alloy system.

关键词： Elastic properties Phonon Solid solution strengthen Force constants CALPHAD

Research progress of permanent ferrite magnet materials

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2024年第6期31卷 1723-1762页

作者： XU Bin CHEN yu-feng ZHOU yu-juan LUO Bi-yun ZHONG Shou-guo LIU xing-ao School of Minerals Processing and Bioengineering Central South UniversityChangsha 410083China

Permanent ferrite magnet materials are extensively employed due to their exceptional magnetic properties and *** fast development in electromobile and household appliance industries contributes to a new progress in permanent ferrite *** paper reviews the deveolpement and progress of permanent ferrite magnet industry in recent *** emergence of new raw material,the advancement of perparation methods and manufacturing techniques,and the potential applications of permanent ferrite materials are introduced and ***,nanocrystallization plays a crucial role in achieving high performance at a low cost and reducing reliance on rare earth resources,and therefore it could be a promising development trendency.

关键词： permanent ferrite magnetic materials high-performance nanosizing