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Simulation of roof snow loads based on a multi-layer snowmelt model:Impact of building heat transfer

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Building Simulation 2024年第6期17卷 907-932页

作者： Xuanyi Zhou Heng Chen yue Wu Tiange zhang State Key Laboratory of Disaster Reduction in Civil Engineering Tongji UniversityShanghai200092China

To investigate the impact of building heat transfer on roof snow loads,roof snow loads and snow load thermal coefficients from 61 Chinese sites over a period of 50 years are simulated based on basic meteorological data such as temperature,humidity,wind speed,and precipitation,and a multi-layer snowmelt model considering the building heat ***,the accuracy of the multi-layer snowmelt model is validated using the data of observed ground snow load and roof snow melting *** relationship between meteorological conditions,snow cover characteristics,and thermal coefficients of snow loads in three representative sites is then ***,the characteristics of thermal coefficients in each zone are analyzed by combining them with the statistical results of meteorological data from 1960 to 2010,and the equations of thermal coefficients in different zones on indoor temperatures and roof heat transfer coefficients are fitted ***,the equations in this paper are compared with the thermal coefficients in the main snow load *** results indicate that the snowmelt model using basic meteorological data can effectively provide samples of roof snow *** the cold zone where the snow cover lasts for a long time and does not melt easily,the thermal coefficients of the snow loads on the heating buildings are lower than those in the warm zone due to the long-term influence of the heat from inside the *** coefficients are negatively correlated with indoor temperatures and roof heat transfer *** the indoor temperature is too low or the roof insulation is good,the roof snow load may exceed the ground snow *** thermal coefficients for heated buildings in the main snow load codes are more conservative than those calculated in this paper,and the thermal coefficients for buildings with lower indoor temperatures tend to be smaller.

关键词： snowmelt model roof snow load building heat transfer thermal coefficient load code

Structural color of metallic glass through picosecond laser

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Chinese Physics B 2024年第10期33卷 120-128页

作者： yue’e zhang Xing Tong Yuqiang Yan Shuo Cao Hai-Bo Ke Wei-hua Wang College of Physics Liaoning UniversityShenyang 110036China Songshan Lake Materials Laboratory Dongguan 523808China Institute of Physics Chinese Academy of SciencesBeijing 100190China

The alteration in surface color of metallic glasses(MGs)holds great significance in the context of microstructuredesign and commercial *** is essential to accurately describe the structures that are formed during the laser and colorseparation processes in order to develop practical laser coloring *** to the high oxidation sensitivity of Labasedmetallic glass,it can broaden the color range but make it more *** coloring by laser processing on thesurface of La-based metallic glass can be conducted after thermoplastic *** is particularly important to clarify therole of structure and composition in the surface coloring *** aim is to study the relationship between amorphoussurface structural color,surface geometry,and oxide formation by laser processing in metallic *** findings revealedthat the periodic structure primarily determines the surface color at laser energy densities below 1.0 J/mm^(2).In contrast,thesurface color predominantly depends on the proportion of oxides that are formed when energy densities exceed 1.0 J/mm^(2).Consequently,this study provides a novel concept for the fundamental investigation of laser coloring and establishes a newavenue for practical application.

关键词： metallic glass picosecond laser periodic structure oxides

Mechanical Performance of Bio-inspired Bidirectional Corrugated Sandwich Pressure Shell Under External Hydrostatic Pressure

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China Ocean Engineering 2024年第2期38卷 297-312页

作者： zhang Yi CHEN yue YUN Lai LIANG Xu Ocean College Zhejiang UniversityZhoushan 316000China Hainan Institute Zhejiang UniversitySanya 572000China

This paper aims to enhance the compression capacity of underwater cylindrical shells by adopting the corrugated sandwich structure of *** cuttlebone suffers uniaxial external compression,while underwater cylindrical shells are in a biaxial compressive stress *** suit the biaxial compressive stress state,a novel bidirectional corrugated sandwich structure is proposed to improve the bearing capacity of cylindrical *** static and buckling analysis for the sandwich shell and the unstiffened cylindrical shell with the same volume-weight ratio are studied by numerical *** is indicated that the proposed sandwich shell can effectively reduce the ratio between circumferential and axial stress from 2 to 1.25 and improve the critical buckling load by about 1.63 *** simulation shows that optimizing and adjusting the structural parameters could significantly improve the advantage of the sandwich ***,the hydrostatic pressure tests for shell models fabricated by 3D printing are carried *** to the experimental results,the overall failure position of the sandwich shell is at the center part of the sandwich *** has been found the average critical load of the proposed sandwich shell models exceeds two times that of the unstiffened shell ***,the proposed bio-inspired bidirectional corrugated sandwich structure can significantly enhance the pressure resistance capability of cylindrical shells.

关键词： bio-inspiration bidirectional corrugation sandwich shell external pressure buckling

U-Net Models for Representing Wind Stress Anomalies over the Tropical Pacific and Their Integrations with an Intermediate Coupled Model for ENSO Studies

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Advances in Atmospheric Sciences 2024年第7期41卷 1403-1416页

作者： Shuangying Du Rong-hua zhang Key Laboratory of Ocean Circulation and Waves Institute of OceanologyChinese Academy of SciencesQingdao266071China School of Marine Sciences Nanjing University of Information Science and TechnologyNanjing210044China Laosan Laboratory Qingdao266237China University of Chinese Academy of Sciences Beijing100049China

El Niño-Southern Oscillation(ENSO)is the strongest interannual climate mode influencing the coupled ocean-atmosphere system in the tropical Pacific,and numerous dynamical and statistical models have been developed to simulate and predict *** some simplified coupled ocean-atmosphere models,the relationship between sea surface temperature(SST)anomalies and wind stress(τ)anomalies can be constructed by statistical methods,such as singular value decomposition(SVD).In recent years,the applications of artificial intelligence(AI)to climate modeling have shown promising prospects,and the integrations of AI-based models with dynamical models are active areas of *** study constructs U-Net models for representing the relationship between SSTAs andτanomalies in the tropical Pacific;the UNet-derivedτmodel,denoted asτUNet,is then used to replace the original SVD-basedτmodel of an intermediate coupled model(ICM),forming a newly AI-integrated ICM,referred to as *** simulation results obtained from ICM-UNet demonstrate their ability to represent the spatiotemporal variability of oceanic and atmospheric anomaly fields in the equatorial *** the ocean-only case study,theτUNet-derived wind stress anomaly fields are used to force the ocean component of the ICM,the results of which also indicate reasonable simulations of typical ENSO *** results demonstrate the feasibility of integrating an AI-derived model with a physics-based dynamical model for ENSO modeling ***,the successful integration of the dynamical ocean models with the AI-based atmospheric wind model provides a novel approach to ocean-atmosphere interaction modeling studies.

关键词： U-Net models wind stress anomalies ICM integration of AI and physical components

Ultra-efficient and parameter-free computation of submicron thermal transport with phonon Boltzmann transport equation

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Fundamental Research 2024年第4期4卷 907-915页

作者： yue Hu Yongxing Shen hua Bao University of Michigan-Shanghai Jiao Tong University Joint Institute Shanghai Jiao Tong UniversityShanghai 200240China

Understanding thermal transport at the submicron scale is crucial for engineering applications,especially in the thermal management of electronics and tailoring the thermal conductivity of thermoelectric *** the submicron scale,the macroscopic heat diffusion equation is no longer valid and the phonon Boltzmann transport equation(BTE)becomes the governing equation for thermal ***,previous thermal simulations based on the phonon BTE have two main limitations:relying on empirical parameters and prohibitive computational ***,the phonon BTE is commonly used for qualitatively studying the non-Fourier thermal transport phenomena of toy *** this work,we demonstrate an ultra-efficient and parameter-free computational method of the phonon BTE to achieve quantitatively accurate thermal simulation for realistic materials and *** properly integrating the phonon properties from first-principles calculations,our method does not rely on empirical material properties *** can be generally applicable for different materials and the predicted results can match well with experimental ***,by developing a suitable ensemble of advanced numerical algorithms,our method exhibits superior numerical *** full-scale(from ballistic to diffusive)thermal simulation of a 3-dimensional fin field-effect transistor with 13 million degrees of freedom,which is prohibitive for existing phonon BTE solvers even on supercomputers,can now be completed within two hours on a single personal *** method makes it possible to achieve the predictive design of realistic nanostructures for the desired thermal *** also enables accurately resolving the temperature profiles at the transistor level,which helps in better understanding the self-heating effect of electronics.

关键词： Submicron thermal transport Boltzmann transport equation Deterministic numerical method Phonon transport Transistors Nanostructured materials

Ti_(3)C_(2)T_(x)/SnO_(2)P–N heterostructure construction boosts room-temperature detecting formaldehyde

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Rare Metals 2024年第1期43卷 267-279页

作者： yue zhang Ming-yue Wang Xiao-Guang San Yan-Bai Shen Guo-Sheng Wang Lei zhang Dan Meng College of Chemical Engineering Shenyang University of Chemical TechnologyShenyang 110142China Institute for Superconducting and Electronic Materials(ISEM) Australian Institute for Innovative Materials(AIIM)University ofWollongongWollongongNSW2500Australia College of Resources and Civil Engineering Northeastern UniversityShenyang 110819China

Formaldehyde is a common atmospheric pollutant produced in industrial production and daily ***,the traditional semiconductor formaldehyde gas sensor cannot work at room temperature,which limits its practical ***,developing high-performance gas sensors for rapidly and accurately detecting formaldehyde at room temperature is an important *** this study,Ti_(3)C_(2)Tx/SnO_(2)heterostructures were constructed,which could selectively detect formaldehyde at room temperature with a response value of 29.16%(10×10^(-6)).In addition,the sensor shows a remarkable theoretical detection limit of 5.09×10^(-9)and good longterm *** functional theory(DFT)simulations reveal that SnO_(2)nano spheres provide the majority of adsorption sites that strongly interact with ***,Ti_(3)C_(2)T_(x)acting as a conductive layer facilitates the transfer of charge carriers so that they show a sensing response to formaldehyde at room ***,the formation of p-n heterostructures between SnO_(2)and Ti_(3)C_(2)T_(x)boosts the Schottky barrier at the interface,which is the critical factor in enhancing the sensing properties by turning the Schottky barrier upon introducing formaldehyde *** perspective is expected to provide instructive guidance for utilizing MXene/metal oxide nanocomposites to improve the gas sensing performance at room temperature.

关键词： Ti_(3)C_(2)T_(x)/SnO_(2)nanocomposites p-n heterostructures Formaldehyde sensing Room temperature DFT calculations

Comparison of corrosion mechanisms of 510L low alloy steel treated by ACS and EPS techniques under various service environments

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Journal of Iron and Steel Research International 2024年第2期31卷 501-518页

作者： Bao-sheng Liu Peng-fei Xu Shao-hua zhang Yan-rui Li Li-ming Mou Jia-li Li yue-zhong zhang Pei-mao Fu Fa-cai Shi College of Materials Science and Engineering Taiyuan University of Science and TechnologyTaiyuan030024ShanxiChina College of Chemical and Biological Engineering Taiyuan University of Science and TechnologyTaiyuan030024ShanxiChina Technical Center Taiyuan Iron and Steel(Group)Co.Ltd.Taiyuan030003ShanxiChina

The corrosion mechanism of 510L low alloy steel treated by acid-cleaned surface(ACS)and eco-pickled surface(EPS)techniques in three simulated solutions(S0:atmospheric environment;S1:soil environment;S2:industrial environment)and the influence of interaction between different corrosive anions on corrosion were *** results show that the total corrosion rates of samples in three simulated solutions were in order of S2>S0>S1,which is simultaneously correlated with initial corrosion dissolution processes as well as after the formation of corrosion ***3−will inhibit the initial corrosion owing to the formation of films,whereas HSO3−will accelerate the dissolutions of the matrix based on the synergistic action of HSO3−and Cl−.On the other hand,there is no significant difference in corrosion rates between the samples treated by ACS and EPS *** EPS technique that is safe,reusable and environmentally friendly can be further widely used in future work.

关键词： Corrosion mechanism Low alloy steel Simulated solution Surface technique Immersion time

Multidimensional coupled structure-activity relationship models for replacement of SF_(6)

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High Voltage 2024年第2期9卷 484-494页

作者： Mi zhang hua Hou Baoshan Wang College of Chemistry and Molecular Sciences Wuhan UniversityWuhanChina

Computational screening of single gases to replace SF_(6)for electrical insulation has been challenged by the difficulty in combining various mutually exclusive properties especially for dielectric performance with liquefaction and environmental *** reveal the inherent correlations between dielectric strength(Er),boiling point(Tb),and global warming potential(GWP)of dielectric materials,a coupled structure-activity relationship(CSAR)model has been proposed for the first *** means of the generic descriptors,as deduced from the electrostatic potentials,and the specific descriptors,as introduced from the respective microscopic mechanisms,the complex interdependence between Er,Tb,and GWP of the insulation gases is quantitatively characterised by the 3-D coupling *** coupling mechanism for the right balance of properties is uncovered in terms of the first-principle *** CSAR model outperforms the previous SAR models in predicting Er,Tb,and GWP simultaneously in a self-consistent *** importantly,the concept of CSAR could be extended readily to any multidimensional macroscopic *** replacement compounds have been identified tentatively to be the promising candidates to replace SF_(6)using the CSAR model.

关键词： properties. dielectric insulation

Correlative factors of poor prognosis and abnormal cellular immune function in patients with Alzheimer’s disease

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World Journal of Clinical Cases 2024年第6期12卷 1063-1075页

作者： hua Bai Hong-Mei Zeng Qi-Fang zhang yue-Zhi Hu Fei-Fei Deng Department of Neurology The Third Affiliated Hospital of Guizhou Medical University in ChinaDuyun 558099Guizhou ProvinceChina Department of Neurology Guizhou Medical UniversityDuyun 558099Guizhou ProvinceChina Key Laboratory of Medical Molecular Biology Guizhou Medical UniversityGuiyang 550004Guizhou ProvinceChina

BACKGROUND Alzheimer’s disease(AD)is a serious disease causing human dementia and social *** quality of life and prognosis of AD patients have attracted much *** role of chronic immune inflammation in the pathogenesis of AD is becoming more and more *** To study the relationship among cognitive dysfunction,abnormal cellular immune function,neuroimaging results and poor prognostic factors in *** A retrospective analysis of 62 hospitalized patients clinical diagnosed with AD who were admitted to our hospital from November 2015 to November *** cognitive dysfunction performance characteristics,laboratory test data and neuroimaging data from medical records within 24 h of admission,including Mini Mental State Examination Scale score,drawing clock test,blood T lymphocyte subsets,and neutrophils and lymphocyte ratio(NLR),disturbance of consciousness,extrapyramidal symptoms,electroencephalogram(EEG)and head nucleus magnetic spectroscopy(MRS)and other *** logistic regression analysis was used to determine independent prog-nostic *** modified Rankin scale(mRS)was used to determine whether the prognosis was *** correlation between drug treatment and prognostic mRS score was tested by the rank sum *** Univariate analysis showed that abnormal cellular immune function,extrapyramidal symptoms,obvious disturbance of consciousness,abnormal EEG,increased NLR,abnormal MRS,and complicated pneumonia were related to the poor prognosis of AD *** logistic regression analysis showed that the decrease in the proportion of T lym-phocytes in the blood after abnormal cellular immune function(odd ratio:2.078,95%confidence interval:1.156-3.986,P<0.05)was an independent risk factor for predicting the poor prognosis of *** number of days of donepezil treatment to improve cognitive function was negatively correlated with mRS score(r=0.578,P<0.05).CONCLUSION The decrease in the proportion of T

关键词： Alzheimer’s disease Cellular immunity Prognosis T lymphocytes Magnetic resonance spectroscopy