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Surface and interface analysis of HAP/TiO2 composite films on Ti6Al4V

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中国有色金属学会会刊：英文版 2004年第z1期14卷 193-198页

作者： SU Bing ZHANG Weng-guang YU Xu-dong wang Cheng-tao School of Mechanical and Power Engineering Shanghai Jiaotong University Shanghai 200030 China School of Mechanical and Power Engineering Shanghai Jiaotong University Shanghai 200030 China 1st Department Artillery Academy of PLA of China Hefei 230031 China School of Mechanical and Power Engineering Shanghai Jiaotong University Shanghai 200030 China

The composite films constituted of hydroxyapatite (HAP) submicron particles embedded in the gel composed of the titania nanoparticles were prepared on commercial Ti6Al4V plates with titania buffer layer obtained by a spin-coating technique. The films were annealed in air at 450 ℃, 550 ℃ and 650 ℃, respectively. The phase formation, surface morphology, andinterfacial microstructure of the films were investigated by X-ray diffraction(XRD),Fourier transform infrared spectroscopy (FT-IR), field emission-scanning electron microscopy(FE-SEM) and energy dispersive X-ray (EDS) analysis. The results show that the as-prepared films are all well-crystallized, dense,homogeneous, and there was a close interfacial bond between the film and the substrate. The results of adhesion test indicate that there is a good bonding strength between the film and the substrate. The bone-like apatite formation on the surface of the films after immersion in acellular simulatedbody fluid(SBF) validated their bioactivities.

关键词： titanium dioxide hydroxyapatite composite film spin-coating technique

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The AIMS Site Survey

Research in Astronomy and Astrophysics 2023年第11期23卷 14-24页

作者： Xing-Ming Bao Jian wang Shuai Jing Yuan-Yong Deng dong-guang wang Key Laboratory of Solar Activity National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

This paper reports site survey results for the Infrared System for the Accurate Measurement of Solar Magnetic Field, especially in Saishiteng Mountain, Qinghai, China. Since 2017, we have installed a weather station,spectrometers for precipitable water vapor, and Solar Differential Image Motion Monitor, and have carried out observations on weather elements, precipitable water vapor, and daytime seeing conditions for more than one year in almost all candidates. At Mt. Saishiteng, the median value of daytime precipitable water vapor is 5.25 mm and its median value in winter season is 2.1 mm. The median value of the Fried parameter of daytime seeing observation at Saishiteng Mountain is 3.42 cm. Its solar direct radiation data show that solar average observable time is 446 minutes per day and premium time is 401 minutes per day in 2019 August.

关键词： site testing atmospheric effects methods:analytical

Diagnostic value of controlled attenuation parameter for liver steatosis in patients with chronic hepatitis B

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World Journal of Gastroenterology 2014年第30期20卷 10585-10590页

作者： Chun-Yan wang Wei Lu dong-Sheng Hu guang-dong wang Xiao-Jing Cheng Tianjin Second People’s Hospital Rizhao People’s Hospital Tianjin Medical University

AIM: To study the diagnostic value of controlled attenuation parameter (CAP), evaluated by transient elastography, for liver steatosis in patients with chronic hepatitis B (CHB).

关键词： Transient elastography Controlled attenuation parameter Chronic hepatitis B Liver steatosis

Interference effect on the liquid-crystal-based Stokes polarimeter

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Chinese Physics B 2020年第12期29卷 286-296页

作者： Jun-Feng Hou dong-guang wang Yuan-Yong Deng Zhi-Yong Zhang Ying-Zi Sun Key Laboratory of Solar Activity National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 101408China

The Stokes polarimeter based on liquid crystal variable retarders(LCVRs)is envisaged as a promising novel technique for polarization measurement in space applications due to the inherent advantage of eliminating the need for conventional rotating polarizing optics and increasing the measuring ***,the intrinsic multi-beam interference in LCVRs limits its polarization accuracy by several *** to eliminate the influence of the interference effect becomes an urgent issue for the liquid-crystal-based Stokes *** present study introduces a simplified but effective interference model based on the thin-film optics and polarized light theory to simulate the relationship between the interference effect of the LCVRs-based Stokes polarimeter and the polarization *** simulation results show that the transmittance variation of LCVR with the derived voltage is caused by multi beam interference between the indium tin oxide(ITO)film and the liquid crystal within LCVR,which produces a few percent of instrumental *** instrumental polarization is about 0.01 and different for different *** optimization method was proposed to reduce the instrumental polarization to 0.002,effectively improving the polarization sensitivity of the Stokes polarimeter limited by the *** addition,an experimental setup was built up to measure and analyze the influence of the interference effect of the LCVRs-based Stokes polarimeter on the polarization accuracy before and after the *** experiment results are in good agreement with the simulation.

关键词： polarimetry liquid crystal variable retarder(LCVR) interference effect

Irradiation study of liquid crystal variable retarder for Full-disk Magneto-Graph payload onboard ASO-S mission

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Chinese Physics B 2020年第7期29卷 346-355页

作者： Jun-Feng Hou Hai-Feng wang Gang wang Yong-Quan Luo Hong-Wei Li Zhen-Long Zhang dong-guang wang Yuan-Yong Deng Key Laboratory of Solar Activity National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Institute of Fluid Physics China Academy of Engineering PhysicsMianyang 621900China National Space Science Center Chinese Academy of SciencesBeijing 100190China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 101408China

The Advanced Space-based Solar Observatory(ASO-S)is a mission proposed by the Chinese Solar Physics Commu*** one of the three payloads of ASO-S,the Full-disc Magneto-Graph(FMG)will measure the photospheric magnetic fields of the entire solar disk with high spatial and temporal resolution,and high magnetic sensitivity,where liquid crystal variable retarder(LCVR)is the key to whether FMG can achieve its scientific *** far,there is no space flight experience for ***,irradiation study for LCVRs becomes more important and urgent in order to make sure their safety and reliability in space *** this paper,γirradiation,proton irradiation,and ultra-violet(UV)irradiation are tested for LCVRs *** optical and chemical properties during irradiation tests are measured and *** optical properties,there is no significant change in those parameters FMG payload concerned except the *** there is no drastic degradation in the retardation versus voltage during irradiations,the amount of retardation variation is much higher than the instrument ***,an in-flight retardation versus voltage should be added in FMG payload,reducing or even avoiding the impact of retardation *** chemical properties,the clearing point and birefringence of the LC materials almost have no change;the ion density dose not change below 60 krad[Si],but begin to increase dramatically above 60 krad[Si].

关键词： solar telescope liquid crystal variable retarder(LCVR) irradiation

Distortion mapping correction in the AIMS primary mirror testing by a computer-generated hologram

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Research in Astronomy and Astrophysics 2021年第7期21卷 99-106页

作者： Ke-Wei E Jian-Ke Zhao Bo wang dong-guang wang Yu-Liang Shen Xin Fu Song-Bo Xu Jing Li Xun Xue Ming Chang Yan Zhou Xi’an Institute of Optics and Precision Mechanics Chinese Academy of SciencesXi’an 710119China Nanjing Astronomical Instruments Chinese Academy of SciencesNanjing 210042China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China

The National Solar Observatory is currently developing the Accurate Infrared Magnetic Field Measurements of the Sun(AIMS). The primary mirror of the AIMS solar telescope is an off-axis parabolic with a diameter of 1 m and with a large off-axis amount of 1 m. Due to the surface figure of the primary mirror under the used state is directly related to image quality of the whole system, a computer-generated hologram(CGH) is carried out to test the primary mirror, and the test results are used to polish the mirror to a higher surface accuracy. However, the fact that the distortion exists in the testing results leads to the failure of a further guide to deterministic optical processing. In this paper, a distortion correction method is proposed, which uses an orthogonal set of vector polynomials to mapping the coordinates of the mirror and the pixels of fringes, and then an interpolation method is adopted to obtain the corrected results. The testing accuracy by using CGH is also verified by an auto-collimate test experiment. According to the distorted corrected results, the root-mean-square of the surface figure is about 1/50λ(λ=632.8 nm) after polishing.

关键词： telescopes techniques:interferometric methods:astronomical instrumentation methods and techniques

A Region Selection Method for Real-time Local Correlation Tracking of Solar Full-disk Magnetographs

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Research in Astronomy and Astrophysics 2022年第9期22卷 106-115页

作者： Yang Bai Jia-Ben Lin Xian-Yong Bai Xiao Yang dong-guang wang Yuan-Yong Deng Xiao-Ming Zhu Xing Hu Wei Huang Li-Yue Tong Key Laboratory of Solar Activity National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

Hundreds of images with the same polarization state are first registered to compensate for the jitters during an observation and then integrated to realize the needed spatial resolution and sensitivity for solar magnetic field measurement. Due to the feature dependent properties of the correlation tracker technique, an effective method to select the feature region is critical for low-resolution full-disk solar filtergrams, especially those with less significant features when the Sun is quiet. In this paper, we propose a region extraction method based on a Hessian matrix and information entropy constraints for local correlation tracking(CT) to get linear displacement between different images. The method is composed of three steps:(1) extract feature points with the Hessian matrix,(2)select good feature points with scale spaces and thresholds, and(3) locate the feature region with the twodimensional information entropy constraints. Both the simulated and observational experiments demonstrated that our region selection method can efficiently detect the linear displacement and improve the quality of a groundbased full-disk solar magnetogram. The local CT with the selected regions can obtain displacement detection results as good as the global CT and at the same time significantly reduce the average calculation time.

关键词： Sun:photosphere Sun:magnetic fields techniques:image processing

Effect of different quenching processes following solid-solution treatment on properties and precipitation behaviors of 7050 alloy

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Transactions of Nonferrous Metals Society of China 2018年第11期28卷 2163-2173页

作者： Lei KANG Gang ZHAO guang-dong wang Kun LIU Ni TIAN Key Laboratory for Anisotropy and Texture of Materials Ministry of EducationSchool of Materials Science and EngineeringNortheastern UniversityShenyang 110819China Department of Applied Science University of Quebec at ChicoutimiQuebecG7H 2B1Canada

The effects of quenching in different ways following solid-solution treatment on properties and precipitation behaviors of7050 alloy were investigated by transmission electron microscopy （TEM）, scanning electron microscopy （SEM）, selected areaelectron diffraction （SAED）, hardness and electrical conductivity tests. Results show that after quenching in different ways, electricalconductivity of the alloy decreases rapidly in the first 48 h of natural aging. The electrical conductivity of 7050 alloy in natural agingstate is determined by the size and density of GP zones, and the size of GP zones is the main factor. After natural aging for 70 d, thesize of GP zones is 1.8-2.6 nm in matrix of the immersion quenched sample and it is 1.4-1.8 nm in matrix of both water mist andforced air quenched samples. After natural and artificial peak aging, the hardness of the water mist quenched sample is HV 193.6 andits electrical conductivity is 30.5% （IACS） which are both higher than those of the immersion quenched sample. Therefore, watermist quenching is an ideal quenching method for 7050 alloy sheets after solid-solution treatment.

关键词： 7050 aluminum alloy quenching method precipitation behavior electrical conductivity nucleation site

Spectro-polarimetric observations at the NVST:*** polarization calibration and primary measurements

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Research in Astronomy and Astrophysics 2020年第4期20卷 7-18页

作者： Jun-Feng Hou Zhi Xu Shu Yuan Yu-Chao Chen Jian-Guo Peng dong-guang wang Jun Xu Yuan-Yong Deng Zhen-Yu Jin Kai-Fan Ji Zhong Liu National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China Yunnan Observatories Chinese Academy of SciencesKunming 650216China

This paper is devoted to the primary spectro-polarimetric observation performed at the New Vacuum Solar Telescope(NVST)of China since 2017,and our aim is to precisely evaluate the real polarimetric accuracy and sensitivity of this polarimetry by using full Stokes spectro-polarimetric observations of the photospheric line Fe I 532.4 *** the work,we briefly describe the salient characteristic of the NVST as a polarimeter in terms of technology and then characterize its instrumental polarization based on the operation in 2017 and *** is verified that the calibration method utilizing the instrumental polarization calibration unit(ICU)is stable and *** calibration accuracy can reach up to 3×10^-*** on the scientific observation of NOAA Active Region 12645 on 2017 April 5,we estimate that the residual cross-talk from Stokes I to Stokes Q,U and V,after the instrumental polarization calibration,is about 4×10^-3 on average,which is consistent with the calibration accuracy and close to the photon *** polarimetric sensitivity(i.e.,the detection limit)for polarized light is of the order of 10-3 with an integration time over 20 *** modulation rate is indeed an issue for the present *** present NVST polarimeter is expected to be integrated with a high-order adaptive optics system and a field scanner to realize 2 D vector magnetic field measurements in the following instrumentation update.

关键词： techniques:polarimetric techniques:spectroscopic Sun:magnetic fields