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thickness measurement of GaN epilayer using high resolution X-ray diffraction technique

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Science China(Physics,Mechanics & Astronomy) 2003年第4期46卷 437-440页

作者：冯淦朱建军沈晓明张宝顺赵德刚王玉田杨辉梁骏吾 State Key Laboratory on Integrated Optoelectronics Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China

In this paper we propose a new method for measuring the thickness of the GaN epilayer, by using the ratio of the integrated intensity of the GaN epilayer X-ray diffraction peaks to that of the sapphire substrate ones. This ratio shows a linear dependence on the GaN epilayer thickness up to 2 μm. The new method is more accurate and convenient than those of using the relationship between the integrated intensity of GaN epilayer diffraction peaks and the GaN thickness. Besides, it can eliminate the absorption effect of the GaN epilayer.

关键词： GaN, X-ray diffraction, thickness

Band engineering of valleytronics WSe_(2)–MoS_(2)heterostructures via stacking form,magnetic moment and thickness

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Chinese Physics B 2023年第10期32卷 45-49页

作者：吴彦玮张宗源马亮刘涛郝宁吕文刚龙明生单磊 Information Materials and Intelligent Sensing Laboratory of Anhui Province Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of EducationInstitutes of Physical Science and Information TechnologyAnhui UniversityHefei 230601China State Key Laboratory of Metastable Materials Science&Technology and Key Laboratory for Microstructural Material Physics of Hebei Province School of ScienceYanshan UniversityQinhuangdao 066004China Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions High Magnetic Field LaboratoryChinese Academy of SciencesHefei 230031China Beijing National center for Condensed Matter Physics Beijing Key Laboratory for Nanomaterials and NanodevicesInstitute of PhysicsChinese Academy of SciencesBeijing 100190China

Spin-valley polarization and bandgap regulation are critical in the developing of quantum devices.Here,by employing the density functional theory,we investigate the effects of stacking form,thickness and magnetic moment in the electronic structures of WSe_(2)–MoS_(2)heterostructures.Calculations show that spin-valley polarization maintains in all situations.Increasing thickness of 2H-MoS_(2)not only tunes the bandgap but also changes the degeneracy of the conduction band minimums(CBM)at K/K_(1) points.Gradual increase of micro magnetic moment tunes the bandgap and raises the valence band maximums(VBM)atΓpoint.In addition,the regulation of band gap by the thickness of 2H-MoS_(2)and introduced magnetic moment depends on the stacking type.Results suggest that WSe_(2)–MoS_(2)heterostructure supports an ideal platform for valleytronics applications.Our methods also give new ways of optical absorption regulation in spin-valley devices.

关键词： valleytronics thickness stacking magnetic moment

Arctic sea ice thickness variations from CryoSat-2 satellite altimetry data

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Science China Earth Sciences 2021年第7期64卷 1080-1089页

作者： Feng XIAO Shengkai ZHANG Jiaxing LI Tong GENG Yue XUAN Fei LI Chinese Antarctic Center of Surveying and Mapping Wuhan UniversityWuhan 430079China

Arctic sea ice plays an important role in Earth's climate and environmental system.Sea ice thickness is one of the most important sea ice parameters.Accurately obtaining the sea ice thickness and its changes has great significance to Arctic and global change research.Satellite altimeters can be used to derive long-term and large-scale changes in sea ice thickness.The leads detection is vital in sea ice thickness estimation by using satellite altimetry.Different leads detection methods are compared with remote sensing images,and results show that the detection method that uses waveform parameters can obtain improved results.The model for the conversion of freeboard to thickness is optimized by considering the incomplete penetration of snow for radar altimeters.We derive the estimates of the Arctic sea ice thickness for November 2010 to December 2019 by using the CryoSat-2 altimetry data.The sea ice thickness from the IceBridge and draft data from the upward-looking sonar are used to validate our thickness results.Validations show that the accuracy of our thickness estimates is within 0.2 m.Variations in the Arctic sea ice thickness are analyzed using the PIOMAS model and air and sea surface temperatures.A sharp increase in sea ice thickness is found in 2014.

关键词： CryoSat-2 Arctic sea ice thickness Global change

Development of hyaluronic acid-based edible film for alleviating dry mouth

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Food Science and Human Wellness 2023年第2期12卷 371-377页

作者： Dong-Keon Kweon Jung-Ah Han Jinwoo Bio Co. Ltd.Yongin 17111Korea Department of Food and Nutrition Sangmyung UniversitySeoul 03016Korea

For alleviating dry mouth symptoms,edible films based on hyaluronic acid(HA)with 3 different m(800,1200 and 2300 kDa)were prepared(800 F,1200 F and 2300 F,respectively),and the properties as well as effectiveness were compared.The concentration of each HA dispersion for film forming was set as 3.0%,1.5%or 1.0%,for the m800,1200 and 2300 kDa,respectively,based on the solubility.The 800 F showed the highest thickness,tensile strength,and water vapor transparency,whereas obtained the lowest transparency and elongation at break among samples.All of the HA films showed safety against microorganism during 28 storage day at 40℃with 60%humidity.The optimum site for film attachment in mouth was the palate,and800 F was the most effective for stimulating saliva secretion,eliciting a 38%increase compared to control(without film),tested by the elderly over 65 years old.By the sensory test,800 F was also the most acceptable.Based on above results,the edible films effectively stimulating saliva secretion could be produced with HA,and the physical,sensory characteristics as well as disintegration times of the film could be controlled by mand the dissolution concentration of HA.

关键词： Edible film Hyaluronic acid Saliva stimulating Tensile strength thickness

Sectoral changes of the peripapillary choroidal thickness in patients with unilateral branch retinal vein occlusion

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International Journal of Ophthalmology(English edition) 2019年第3期12卷 472-479页

作者： Na Eun Lee Hae Min Kang Jeong Hoon Choi Hyoung Jun Koh Sung Chul Lee Department of Ophthalmology Catholic Kwandong University College of Medicine International St. Mary's Hospital Choikang Seoul Eye Clinic Institute of Vision Research Department of Ophthalmology Yonsei University College of Medicine

AIM: To investigate sectoral changes in the mean peripapillary choroidal thickness(PCT) in patients with unilateral branch retinal vein occlusion(BRVO). METHODS: This retrospective, interventional study included 41 patients with acute, unilateral BRVO without macular edema. All patients completed at least a 6-month follow-up period. The PCT was measured at eight locations(temporal, superotemporal, superior, superonasal, nasal, inferonasal, inferior, and inferotemporal). In addition to calculating the average of all locations, the peripapillary choroidal area was divided into four sectors: superior(average of superotemporal PCT, superior PCT, and superonasal PCT), temporal, inferior(average of inferotemporal PCT, inferior PCT, and inferonasal PCT), and nasal. RESULTS: In the BRVO-affected eyes, the mean PCT was 177.7±69.8 μm(range, 70.1-396.0 μm) at baseline and 127.8±54.8 μm(range, 56.4-312.1 μm) at 6 mo(P<0.001). In the non-affected contralateral eyes, the mean PCT was 192.5±60.6 μm(range, 61.4-365.0 μm) at baseline and 165.9±61.1 μm(range, 56.8-326.8 μm) at 6 mo(P<0.001). In sectoral analysis, the mean PCT in each sector was significantly reduced in over 6 mo in the BRVO-affected eyes(all P<0.001). In the non-affected contralateral eyes, the mean PCT was not significantly changed in any sector over the 6-month follow-up period(superior sector, P=0.143; temporal sector, P=0.825; inferior sector, P=0.192; and nasal sector, P=0.599).CONCLUSION: Sectoral analysis shows that the mean PCTs in all sectors are reduced significantly over 6 mo in the BRVO-affected eyes, but not in the non-affected contralateral eyes.

关键词： branch retinal vein occlusion choroid choroidal thickness peripapillary choroidal thickness

Improving Joint Morphologies and Tensile Strength of Al/Mg Dissimilar Alloys Friction Stir Lap Welding by Changing Zn Interlayer thickness

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Acta Metallurgica Sinica(English Letters) 2019年第11期32卷 1385-1395页

作者： Jinglin Liu Shiyu Niu Rong Ren Shude Ji Lei Wang Zan Lv College of Aerospace Engineering Shenyang Aerospace UniversityShenyang 110136China Shenyang Institute of Standardization Shenyang 110021China

The pure Zn foils with different thicknesses(0.02, 0.05, 0.1, 0.2 and 0.3 mm) were selected as interlayers to improve the quality of friction stir lap welding joint of 7075-T6 Al and AZ31 B Mg dissimilar alloys. The effects of the interlayer thickness on joint formation, microstructure and tensile strength were analyzed. The results displayed that the maximum length of the boundary between stir zone(SZ) and thermo-mechanically affected zone in lower plate was obtained by the addition of the Zn interlayer with 0.05 mm thickness. The Mg–Zn intermetallic compounds(IMCs) were discontinuously distributed in the SZ, replacing the continuous Al–Mg IMCs. The size of Mg–Zn IMCs increased with the increase in the thickness of the Zn interlayer. The maximum tensile shear strength of 276 N mm-1 was obtained by the addition of 0.05 mm Zn foil, which increased by 45.6% of that of the joint without the Zn foil addition.

关键词： Al/Mg dissimilar alloys Friction stir lap welding Zn foil thickness Microstructure Tensile shear strength

Contraction and warming of Antarctic Bottom Water in the Amundsen Sea

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Acta Oceanologica Sinica 2022年第4期41卷 68-79页

作者： Yu Bai Liang Zhao Jingen Xiao Shiying Lin College of Marine and Environmental Sciences Tianjin University of Science and TechnologyTianjin 300457China School of Marine Science and Technology Tianjin UniversityTianjin 300072China

Antarctic Bottom Water(AABW)plays an important role in the meridional overturning circulation and contributes significantly to global heat transport and sea level rise(SLR).Based on the Global Ocean(1/12)°Physical Reanalysis(GLORYS12V1)products and conductivity-temperature-depth instrument data from the World Ocean Circulation Experiment hydrographic program,we analyzed the trends in the thickness,volume,temperature,salinity,and neutral density of the AABW in the Amundsen Sea from 1993 to 2017.Over the past 25 years,the volume has decreased by 3.45×10^(12) m^(3)/a,thinning at a rate of 5 m/a.In the vertical direction,the contraction of the AABW is compensated by the volume expansion of the Circumpolar Deep Water.As the volume of AABW decreases,the temperature of the AABW increases by about 0.002℃/a.This warming is equivalent to a heat flux of 0.27 W/m^(2).A local SLR is produced due to thermal expansion of 0.35 mm/a.During the study period,the neutral density decreased by 0.0003 kg/(m^(3)·a)due to warming.In the horizontal direction,the volume of AABW flowing from the Ross Sea into the Amundsen Sea gradually decreases and the temperature of the AABW increases continuously.The horizontal transport loss of the AABW volume is 4.07×10^(14) m^(3) and the horizontal heat transport results in a 0.03℃ increase in the temperature of the AABW.

关键词： Antarctic Bottom Water Amundsen Sea thickness volume hydrographic property

Integrity of the hip capsule measured with magnetic resonance imaging after capsular repair or unrepaired capsulotomy in hip arthroscopy

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World Journal of Orthopedics 2022年第4期13卷 400-407页

作者： Niels H Bech Lode A van Dijk Sheryl de Waard Gwendolyn Vuurberg Inger N Sierevelt Gino MMJ Kerkhoffs Daniël Haverkamp Department of Orthopedic Surgery Amsterdam University Medical CenterAmsterdam 1105 AZNetherlands Department of Orthopedic Surgery Xpert Orthopedic Surgery ClinicAmsterdam 1101 EANetherlands Department of Orthopedic Surgery Tergooi ZiekenhuisHilversum 1213 XZNetherlands Department of Radiology and Nuclear Medicine Rijnstate HospitalArnhem 6815 ADNetherlands Department of Radiology and Nuclear Medicine Amsterdam University Medical CenterAmsterdam 1105 AZNetherlands Centre for Orthopaedic Research Spaarne ZiekenhuisHoofddorp 2134 TMNetherlands Academic Center for Evidence-Based Sports Medicine Amsterdam University Medical CenterAmsterdam 1105 AZNetherlands Amsterdam Collaboration on Health and Safety in Sports Amsterdam UMC/IOC Research CenterAmsterdam 1105 AZNetherlands

BACKGROUND Current literature shows no clear answer on the question how to manage the capsule after hip arthroscopy.Regarding patient reported outcome measures there seems to be no difference between capsular repair or unrepaired capsulotomy.AIM To evaluate and compare the integrity of the hip capsule measured on a magnetic resonance imaging(MRI)scan after capsular repair or unrepaired capsulotomy.METHODS A case series study was performed;a random sample of patients included in a trial comparing capsular repair vs unrepaired capsulotomy had a postoperative MRI scan.The presence of a capsular defect and gap size were independently evaluated on MRI.RESULTS A total of 28 patients(29 hips)were included.Patient demographics were comparable between treatment groups.There were 2 capsular defects in the capsular repair group and 7 capsular defects in the unrepaired capsulotomy group(P=0.13).In the group of patients with a defect,median gap sizes at the acetabular side were 5.9 mm(range:2.7-9.0)in the repaired and 8.0 mm(range:4.5-18.0)in the unrepaired group(P=0.462).At the muscular side gap sizes were 6.6 mm(range:4.1-9.0)in the repaired group and 11.5 mm(range:3.0-18.0)in the unrepaired group(P=0.857).The calculated Odds ratio(OR)for having a capsular defect with an increasing lateral center-edge(CE)angle was 1.12(P=0.06).The OR for having a capsular defect is lower in the group of patients that underwent a labral repair with an OR of 0.1(P=0.05).CONCLUSION There is no significant difference in capsular defects between capsular repair or unrepaired capsulotomy.Regarding clinical characteristics our case series shows that a larger CE angle increases the likelihood of a capsular defect and the presence of a labral repair decreases the likelihood of a capsular defect.

关键词： Hip Arthroscopy Magnetic resonance imaging Capsule thickness

Modeling of the Relationship Between Pore Size Distribution and thickness of Ceramic MF Membrane

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Chinese Journal of Chemical Engineering 1998年第3期6卷 38-48页

作者：董军航王沛徐南平时钧 Jerry Y.S.Lin Department of Chemical Engineering University of Cincinnati Cincinnati Ohio OH 45221 USA

The pore size distribution(PSD)measured by the gas bubble point(GBP)method ofceramic microfiltration(MF)membranes prepared by suspension technique was found to be signifi-cantly influenced by the membrane thickness.A culm-like model for pore structure was introduced tocharacterize the membrane pores instead of the conventional model which does not reflect the radiusvariation along the pore passages and is unable to explain the thickness effect on the membrane PSD.A laminate structure,taking the culm-like model for pore structure into consideration,was hypoth-esized for ceramic MF membranes.A mathematical model was then established to quantitativelydescribe the relationship between the membrane number PSD and the membrane thickness.Goodresults were obtained for the correlation of mean pore size and simulation of the PSD for ceramicMF membranes.

关键词： modeling pore structure pore size distribution thickness ceramic membrane