Mica-stabilized polyethylene glycol composite phase change materials for thermal energy storage

Mica was used as a supporting matrix for composite phase change materials(PCMs) in this work because of its distinctive morphology and structure.Composite PCMs were prepared using the vacuum impregnation method,in which mica served as the supporting material and polyethylene glycol(PEG) served as the PCM.Fourier transform infrared and X-ray diffraction analysis confirmed that the addition of PEG had no effect on the crystal structure of mica.Moreover,no chemical reaction occurred between PEG and...     

Comparative analysis by simulating and testing pole impact for hot stamping front crossbeam of automobile

Hot stamping 22MnB5 steel plate with ultra-high strength has been widely used for body structural members in consideration of automobile safety and lightweight.This paper presents a verification program of simulating and testing pole impact in order to verify if the front crossbeam reinforcement assembly can meet the design requirements,reduce the overall vehicle simulation and test cost and shorten the operation period.In the same condition,the simulation proved conforming to the design requirements;however,the bumper cracked at the impacting point in the course of pole impact test.The analysis of the crack by optical microscope,Vickers and scanning electron microscope indicates that mixture of ferrite,bainite and martensite was produced in the weld heat-affected zone of the 340/590DP tow hook holder and the 22MnB5 front crossbeam;therefore,their hardness and mechanical property were reduced obviously,so that they fractured when impacted.No welding process with continuous weld but spot welding or other bonding method may be employed for the reason that the capacity of the 22MnB5 steel plate in the weld heat-affected zone was reduced obviously.     

Transformer-Based Deep Learning Network for Tooth Segmentation on Panoramic Radiographs

Panoramic radiographs can assist dentist to quickly evaluate patients’ overall oral health status. The accurate detection and localization of tooth tissue on panoramic radiographs is the first step to identify pathology, and also plays a key role in an automatic diagnosis system. However,the evaluation of panoramic radiographs depends on the clinical experience and knowledge of dentist,while the interpretation of panoramic radiographs might lead misdiagnosis. Therefore, it is of great significan...     

方差方量模型中保G—M估计的线性变换

考虑方差分量模型（Ｙ，Ｘβ，Σ↑ｔ↓ｉ＝１σｉ＾２Ｖｉ），假设Ｘβ的Ｇ－Ｍ估计存在。本文给出了可观测的随机向量Ｙ的线性变换Ｆ为保Ｇ－Ｍ估计的变换（即存在ＦＹ的线性函数为Ｘβ的Ｇ－Ｍ估计）的充要条件，并指出在变换前后的模型中，Ｘβ的Ｇ－Ｍ估计相同。     

STUDY OF CARBOXYL METHYL STARCH ON PAPER STRENGTH

INTRODUCTIONIn China, there is not abundant of wood resourceNon-wood fiber materials, especially like wheastraw and reed, would still be considerably used araw materials of papermaking in a long period ofuture. However, wheat straw pulp and reed pulwith the problem of short fiber and many mixed celllead to the paper in low strength. So in thmanufacture of papermaking, more and moradditives are added to make up the deficiency. Ipapermaking industry, different types of starch anstarch deri…     

Optimal design of basic pulse waveforms for THSS UWB radio systems

1.INTRODUCTION Recently,therehasbeenagreatinterestinUWBra dioforfuturehighrateshort rangewirelesscommu nications[1～4].Forhighlyresolvingmultipathand generatingUWBsignalswithrelativelylowcomplexi ty,UWBradiosystemsusuallyuseTHSSimpulse trainwithPPMtocarrydatainformation[5,6].That iswhyitissometimescalledimpulseradio(IR).The essenceofUWBradioisthatitdoesnotuseasinu soidalcarrierbutinsteadcommunicateswithaTHSS basebandsignalcomposedofsubnanosecondpulses withPPM.Thatis,UWBra…     

Research on Atomic-Scale Investigation of Li Storage Mechanism in Spinel Li4Ti5O12

Nowadays,there is an increasing need for large-scale energy storage with the developments of renewable energy sources including solar and wind power.Among the candidates,Li-ion batteries have been regarded as one of the most important alternatives to power the electric vehicles (EVs) and/or to store electric energy in largescale. Nonetheless,the performance of present Li ion batteries can still not meet the requirements for     

“第二语言水平”概念多解

“第二语言水平”概念的发展推动了第二语言教学的发展。本文分析了“第二语言水平”概念的发展及其在现实生活中的运用,旨在加深学习者对“第二语言水平”概念的不同理解以及让学习者认识到如何提高语言水平。     

Urban structure and the risk of influenza A （H1N1） outbreaks in municipal districts

Changsha was one of the most affected areas during the 2009 A （H 1N 1） influenza pandemic in China. Here, we analyze the spatial-temporal dynamics of the 2009 pan- demic across Changsha municipal districts, evaluate the relationship between case incidence and the local urban spatial structure and predict high-risk areas of influenza A （H1NI）. We obtained epidemiological data on all cases of influenza A （H1NI） reported across municipal districts in Changsha dur- ing period May 2009-December 2010 and data on population density and basic geographic characteristics for 239 primary schools, 97 middle schools, 347 universities, 96 mails and markets, 674 business districts and 121 hospitals. Spatial- temporal K functions, proximity models and logistic regres- sion were used to analyze the spatial distribution pattern of influenza A （H1N1） incidence and the association between influenza A （HINI） cases and spatial risk factors and predict the infection risks. We found that the 2009 influenza A （H 1N 1 ） was driven by a transmission wave from the center of the study area to surrounding areas and reported cases increased significantly after September 2009. We also found that the distribution of influenza A （H 1N1） cases was associ- ated with population density and the presence of nearest public places, especially universities （OR = 10.166）. The final pre- dictive risk map based on the multivariate logistic analysis showed high-risk areas concentrated in the center areas of the study area associated with high population density. Our find- ings support the identification of spatial risk factors and high- risk areas to guide the prioritization of preventive and miti- gation efforts against future influenza pandemics.