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Free-radical evolution and decay in cross-linked polytetrafluoroethylene irradiated by gamma-rays

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Nuclear Science and Techniques 2022年第5期33卷 113-125页

作者： fei-Xiang sha Guo-Jun Cheng Zi-Yue Xuan Yang Liu Wei-Hua Liu Xiao-Dong Zhang Zhong-Feng Tang School of Materials Science and Engineering Anhui University of Science and TechnologyHuainan 232000China shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China National Key Laboratory of Materials Behavior and Evaluation Technology in Space Environment Harbin Institute of TechnologyHarbin 150001China University of Chinese Academy of Sciences Beijing 100049China

Electron spin resonance techniques were employed to investigate the effects of the absorbed dose and post-irradiation conditions on the evolution and decay of free-radicals in cross-linked polytetrafluoroethylene(XPTFE),induced byγ-ray ***-end free-radicals,chain alkyl free-radicals,and tertiary alkyl free-radicals were detected when XPTFE was irradiated under Ar *** corresponding peroxy free-radicals were formed upon exposure of irradiated XPTFE to air;the freeradicals concentration first increased linearly with increasing absorbed dose and then gradually *** free-radicals yield under air atmosphere was greater than that under Ar,and the peroxy free-radicals were preserved for a relatively long time when irradiated XPTFE was stored under air *** chain alkyl free-radicals may be converted to chain end free-radicals byβ-scission,while chain end free-radicals are more sensitive to oxygen than chain alkyl *** the annealing temperature was raised above the a-transition temperature of XPTFE,the decay of the free-radicals was greatly affected and accelerated by the motion of the molecules over the long range.

关键词： Polytetrafluoroethylene Cross-linked polytetrafluoroethylene Electron spinresonance Decay Radiation c-ray

Design and fabrication of smart functional hydrogel wound dressing for diabetic foot ulcer

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Frontiers of Materials Science 2024年第3期18卷 1-18页

作者： Yufei Wang Dandan Hou Hui Zhao Xue Geng Xin Wu Gaobiao Li fei sha Zengguo Feng Zongjian Liu Lin Ye School of Materials Science and Engineering Bejing Institute of TechnologyBeijing 100081China SINOPEC Beijing Research Institute of Chemical Industry Beijing 100013China Department of Vascular Surgery Beijing Luhe HospitalCapital Medical UniversityBeijing 101100China Department of Vascular Surgery Wangjing HospitalChina Academy of Chinese Medical SciencesBejing 100102China Beijing Rehabilitation Hospital Capital Medical UniversityBeijing 100044China

Diabetic foot ulcer(DFU)often evolves into chronic wounds that resist healing over an extended period,sometimes necessitating amputation in severe *** wound management approaches generally fail to control these chronic sores ***,it arouses a huge demand in clinic for a novel wound dressing to treat DFU *** as an ideal delivery system exhibits excellent loading capacity and sustainable release *** also boasts tunable physical and chemical properties adaptable to diverse biomedical scenarios,making it a suitable material for fabricating functional wound dressings to treat *** hydrogel dressings are classified into hemostatic,antibacterial and anti-inflammatory,and healing-promoting hydrogel dressings by associating the pathogenesis of DFU in this *** design and fabrication strategies for the dressings,as well as their therapeutic effects in treating DFU,are extensively ***,this paper highlights future perspectives of multifunctional hydrogel dressings in DFU *** review aims to provide valuable references for material scientists to design and develop hydrogel wound dressings with enhanced capabilities for DFU treatment,and to further translate them intothe clinic inthefuture.

关键词： hydrogel dressing multifunction design fabrication diabetic foot ulcer

Comparison of the Coronal Green-line Intensities with the EUV Measurements from SDO/AIA

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Research in Astronomy and Astrophysics 2022年第7期22卷 191-205页

作者： Xue-fei Zhang Yu Liu Ming-Yu Zhao Ji-Hong Liu Abouazza Elmhamdi Teng-fei Song Zi-Han Li Hong-Bo Li fei-Yang sha Jing-Xing Wang Xiao-Bo Li Yuan-Deng Shen Shun-Qing Liu Hong-fei Liang R.M.Al-shammari Yunnan Observatories Chinese Academy of SciencesKunming 650011China University of Chinese Academy of Sciences Beijing 100049China Shijiazhuang University Shijiazhuang 050035China School of Physical Science and Technology Southwest Jiaotong UniversityChengdu 610031China Department of Physics and Astronomy King Saud UniversityP.O.Box 2455Riyadh 11451Saudi Arabia Yunnan Normal University School of Physics and Electronic InformationKunming 650500China Institute of Space Physics Luoyang Normal UniversityLuoyang 471934China

The intensity of the green line(Fe ⅩⅣ 5303 A) is the strongest in the visible spectrum of the solar corona,and this line has been used as long-term powerful diagnostic tools for studying the coronal configurations and hot plasma ***,it remains unclear and an open question whether there exists close relationship between the green line intensities and the coronal extreme ultraviolet(EUV) line emissions for various coronal *** this paper,we use the green-line data by the Lijiang YOGIS Lyot coronagraph and the EUV data from the Solar Dynamics Observatory/Atmospheric Imaging Assembly instruments in order to perform direct comparisons and analyses,based on two algorithms developed to extract particular features in the low *** is found that,among the correlation coefficients obtained between the intensities of 5303 A and the EUV lines,the coefficients between the green line and the 211 A wavelength for different coronal structures and different limb locations always keep the highest values(ranging from 0.89 to 0.99),which has not been reported *** result can be helpful and promising to link together the various physical processes involved at different heights in the corona by precisely tracking the bright loops or other features observed in 5303 A above the limb down to the correct surface locations revealed by the 211 A ***,the ground-based observations of the coronal green line and the space-based EUV observations at 211 A can advantageously complement each other when there is a need.

关键词： Sun:corona Sun:magnetic fields stars:coronae

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PCB上串扰的耦合机理和优化分析模型

电子与信息学报 2005年第7期27卷 1167-1170页

作者：吕飞燕沙斐北京交通大学电子信息工程学院抗电磁干扰研究中心北京100044

本文从频域与时域两个方面分析了PCB上的串扰的耦合机理,探究了耦合电容以及近端和远端电阻的影响。针对2-π串扰电路模型所提出的时域上的数学优化模型,明确了信号上升沿对干扰输出的影响。并且利用Hyperlynx软件包进行仿真,比较了耦... 详细信息

本文从频域与时域两个方面分析了PCB上的串扰的耦合机理,探究了耦合电容以及近端和远端电阻的影响。针对2-π串扰电路模型所提出的时域上的数学优化模型,明确了信号上升沿对干扰输出的影响。并且利用Hyperlynx软件包进行仿真,比较了耦合电容、耦合长度等的作用结果,仿真结果证明了理论分析的正确性。

关键词：耦合电容串扰优化仿真

PERIODIC DYADIC GREEN’S FUNCTION FOR FIELD ANALYSIS IN EMC CHAMBER

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Journal of Electronics(China) 2006年第6期23卷 906-912页

作者： Lv feiyan Ding Jianjin sha fei EMC Research Section Beijing Jiaotong University Beijing 100044 China

Herein a novel Dyadic Green’s Function (DGF) is presented to calculate the field in ElectroMag-netic Compatibility (EMC) chamber. Due to the difficulty of simulating the whole chamber environment, the analysis combines the DGF formulation and the FEM method, with the latter deals with the reflection from absorbers. With DGF formulation for infinite periodic array structures, this paper investigates electromagnetic field in chamber with truncated arrays. The reflection from the absorber serves as the virtual source contribut-ing to the total field. Hence the whole chamber field calculation can be separated from the work of absorber model set-up. Practically the field homogeneity test and Normal Site Attenuation (NSA) test are carried out to evaluate the chamber performance. Based on the method in this paper, the simulation results agree well with the test, and predict successfully the victim frequency points of the chamber.

关键词： ElectroMagnetic Compatibility (EMC) chamber Dyadic Green's Function (DGF) Periodic array

Active learning for accelerated design of layered materials

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npj Computational Materials 2018年第1期4卷 54-62页

作者： Lindsay Bassman Pankaj Rajak Rajiv K.Kalia Aiichiro Nakano fei sha Jifeng Sun David J.Singh Muratahan Aykol Patrick Huck Kristin Persson Priya Vashishta Collaboratory for Advanced Computing and Simulations University of Southern CaliforniaLos AngelesCA 90089USA Department of Physics and Astronomy University of Southern CaliforniaLos AngelesCA 90089USA Department of Chemical Engineering and Material Science University of Southern CaliforniaLos AngelesCA 90089USA Department of Computer Science University of Southern CaliforniaLos AngelesCA 90089USA Department of Biological Sciences University of Southern CaliforniaLos AngelesCA 90089USA Department of Physics and Astronomy University of MissouriColumbiaMO 65211-7010USA Lawrence Berkeley National Laboratory 1 Cyclotron RoadBerkeleyCA 94720USA

Hetero-structures made from vertically stacked monolayers of transition metal dichalcogenides hold great potential for optoelectronic and thermoelectric *** of the optimal layered material for specific applications necessitates the estimation of key material properties,such as electronic band structure and thermal transport ***,screening of material properties via brute force ab initio calculations of the entire material structure space exceeds the limits of current computing ***,the functional dependence of material properties on the structures is often complicated,making simplistic statistical procedures for prediction difficult to employ without large amounts of data ***,we present a Gaussian process regression model,which predicts material properties of an input hetero-structure,as well as an active learning model based on Bayesian optimization,which can efficiently discover the optimal hetero-structure using a minimal number of ab initio *** electronic band gap,conduction/valence band dispersions,and thermoelectric performance are used as representative material properties for prediction and *** Materials Project platform is used for electronic structure computation,while the BoltzTraP code is used to compute thermoelectric *** optimization is shown to significantly reduce the computational cost of discovering the optimal structure when compared with finding an optimal structure by building a regression model to predict material *** models can be used for predictions with respect to any material property and our software,including data preparation code based on the Python Materials Genomics(PyMatGen)library as well as python-based machine learning code,is available open source.

关键词： Active Python python

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铜管泄露原因分析

金属热处理 2019年第S1期44卷 80-83页

作者：沙菲上海材料研究所上海200437

某单位生产的铜管,在检漏程序中发现泄露。采用化学成分分析、宏观和微观分析、力学试验、金相检验验等方法,对泄露原因进行了分析。结果表明:铜管泄露性质为氢脆。

关键词：铜管氢脆

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EMC混响室电磁场模态研究

电波科学学报 2005年第5期20卷 557-560页

作者：丁坚进沙斐北京交通大学电磁兼容研究室北京100044

混响室谐振腔激励的三维电磁场的推导一般采用并矢格林函数的方法,物理意义不太明显。用本征函数迭加的方法推导混响室有源激励的电磁场分布公式,有利于正确建立混响室电磁结构模型,树立正确的物理概念。并根据公式及其推导过程,分析了... 详细信息

混响室谐振腔激励的三维电磁场的推导一般采用并矢格林函数的方法,物理意义不太明显。用本征函数迭加的方法推导混响室有源激励的电磁场分布公式,有利于正确建立混响室电磁结构模型,树立正确的物理概念。并根据公式及其推导过程,分析了混响室EMC电磁工作机理,以此将EMC混响室电磁工作状态按模式状况进行了系统地分类,为混响室研究设计提供理论指导。

关键词：混响室谐振腔模状态本征函数

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基于幅度概率分布研究骚扰对通信系统的影响

北京交通大学学报 2008年第5期32卷 64-67页

作者：杨飞沙斐王国栋北京交通大学电子信息工程学院北京100044

通过目前学术界广泛关注的幅度概率分布(APD)检测方法与传统电磁兼容测量方法的比较,说明了幅度概率分布统计测量方法的优越性.并且采用统计测量方法来研究骚扰对数字通信系统的影响,以PAM二进制调制系统为例,推导出了骚扰的APD与通信... 详细信息

通过目前学术界广泛关注的幅度概率分布(APD)检测方法与传统电磁兼容测量方法的比较,说明了幅度概率分布统计测量方法的优越性.并且采用统计测量方法来研究骚扰对数字通信系统的影响,以PAM二进制调制系统为例,推导出了骚扰的APD与通信系统误码概率之间的关系式,给出了骚扰的幅度概率分布测量结果与对应干扰下的数字通信系统的误码概率两者之间的联系.本文的研究结果对于制订电子设备的电磁辐射限值具有参考价值.

关键词：电磁兼容幅度概率分布数字通信系统误码概率测量检波器