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Structure of Micro-nano WC-10Co4Cr Coating and Cavitation Erosion Resistance in NaCl Solution

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Chinese Journal of Mechanical Engineering 2017年第5期30卷 1239-1247页

作者： Xiang Ding xu-dong cheng cheng-Qing Yuan Jin Shi Zhang-Xiong Ding State Key Laboratory of Advanced Technology for Materials and Processing Wuhan University of Technology School of Energy and Power Engineering Wuhan University of Technology

Cavitation erosion （CE） is the predominant cause for the failure of overflow components in fluid machinery. Advanced coatings have provided an effective solution to cavitation erosion due to the rapid development of surface engineering techniques. However, the influence of coating structures on CE resistance has not been sys- tematically studied. To better understand their relationship, micro-nano and conventional WC-10Co4Cr cermet coat- ings are deposited by high velocity oxygen fuel spray- ing（HVOF）, and their microstructures are analyzed by OM, SEM and XRD. Meanwhile, characterizations of mechan- ical and electrochemical properties of the coatings are carried out, as well as the coatings＇ resistance to CE in 3.5 wt % NaC1 solution, and the cavitation mechanisms are explored. Results show that micro-nano WC-10Co4Cr coating possesses dense microstructure, excellent mechanical and electrochemical properties, with very low porosity of 0.26 4-0.07% and extraordinary fracture toughness of 5.58 4-0.51 MPa.m1/2. Moreover, the CE resistance of micro-nano coating is enhanced above 50% than conventional coating at the steady CE period in 3.5 wt % NaC1 solution. The superior CE resistance of micro- nano WC-10Co4Cr coating may originate from the unique micro-nano structure and properties, which can effectively obstruct the formation and propagation of CE crack. Thus,a new method is proposed to enhance the CE resistance of WC-10Co4Cr coating by manipulating the microstructure.

关键词： Cavitation erosion resistance Micro-nanostructure - WC- 10Co4Cr coating HVOF

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

Preparation of high emissivity NiCr_2O_4 powders with a spinel structure by spray drying

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International Journal of Minerals,Metallurgy and Materials 2012年第2期19卷 173-178页

作者： xu-dong cheng Jie Min Zhen-qi Zhu Wei-ping Ye State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070 China School of Materials Science and Technology Wuhan University of Technology Wuhan 430070 China

Spray-drying was used to produce the high emissivity NiCr2O4 powders with a spinel structure. Preliminary investigations focused on fabricating the high emissivity powders for infrared radiation coatings and finding the relationship between microstructure and emissivity. The NiCr2O4 powders were characterized for composition, microstructure, and infrared emissivity by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, infrared radiant instrument, and Fourier transform infrared spectra （FT-IR）. Thermogravimetry and differential thermal analysis show that the appropriate baking temperature for NiCr2O4 powder preparation is about 1200？C. The emissivity measurement and FT-IR spectra show that, because of the special spinel structure, the NiCr2O4 powders have a high emissivity about 0.91. Spray-drying is a suitable method to produce the high emissivity ceramic powders.

关键词： emissivity infrared radiation spray drying powders ceramic materials nickel compounds chromium compounds

Synthesis of NiCr_2O_4 spinel coatings with high emissivity by plasma spraying

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International Journal of Minerals,Metallurgy and Materials 2012年第3期19卷 266-270页

作者： Zhen-qi Zhu xu-dong cheng Wei-ping Ye Jie Min School of Materials Science and Technology Wuhan University of Technology Wuhan 430070 China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070 China

Air plasma spraying （APS） was used to produce high emissivity coatings with a NiCr204 spinel structure. The relationship between the emissivity and the crystal structure was investigated. X-ray diffraction （XRD） analyses show that NiCr204 spinel has been fabri- cated with the space group Fd3m. Scanning electron microscope （SEM） photographs show that the coating consists of a laminated structure with homogeneous grains and high porosity because of the unique feature of plasma spraying. The emissivity measurement and Fourier transformation infrared radiation （FT-IR） spectra show that NiCr204 has a high emissivity of about 0.91 because of its special spinel structure APS is a suitable method to produce high emissivity coatings.

关键词： infrared radiation coatings plasma spraying emissivity crystal structure industrial ftLrnaces

Integrated spatial-temporal random speckle spectrometer with high resolution in the C-band

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Photonics Research 2024年第7期12卷 1556-1563页

作者： SHIBO xu JIAHUI ZHANG JUNWEI cheng JIANJI dong Wuhan National Laboratory for Optoelectronics Huazhong University of Science and TechnologyWuhan 430074China Optics Valley Laboratory Wuhan 430074China

The increasing demand for diverse portable high-precision spectral analysis applications has driven the rapid development of spectrometer miniaturization. However, the resolutions of existing miniaturized spectrometers mostly remain at the nanometer level, posing a challenge for further enhancement towards achieving picometerlevel precision. Here, we propose an integrated reconstructive spectrometer that utilizes Mach–Zehnder interferometers and a tunable diffraction network. Through random tuning in the time domain and disordered diffraction in the space domain, the random speckle patterns closely related to wavelength information are obtained to construct the transmission matrix. Experimentally, we achieve a high resolution of 100 pm and precisely reconstruct multiple narrowband and broadband spectra. Moreover, the proposed spectrometer features a simple structure, strong portability, and fast sampling speed, which has great potential in the practical application of high-precision portable spectral analysis.

关键词： speckle random resolution

基于红细胞沉降率和白细胞计数与病程构建化脓性与非化脓性脊柱感染的鉴别诊断模型

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中华医院感染学杂志 2024年第12期34卷 1831-1835页

作者：张呈冉胡小江张广唐博徐东宬高琪乐唐明星刘少华中南大学湘雅医院骨科脊柱外科湖南长沙410008 中南大学湘雅医院国家老年疾病临床医学研究中心湖南长沙410008

目的构建基于C-反应蛋白、红细胞沉降率及血常规指标等构建化脓性脊柱感染(PSI)和非化脓性脊柱感染(NPSI)的鉴别诊断模型.方法收集2019年1月-2022年9月湘雅医院及湘雅博爱医院收治的疑似脊柱感染患者158例为研究对象,根据病理鉴定结果分... 详细信息

目的构建基于C-反应蛋白、红细胞沉降率及血常规指标等构建化脓性脊柱感染(PSI)和非化脓性脊柱感染(NPSI)的鉴别诊断模型.方法收集2019年1月-2022年9月湘雅医院及湘雅博爱医院收治的疑似脊柱感染患者158例为研究对象,根据病理鉴定结果分为PSI组(87例)和非PSI组(71例);分析两组临床资料,比较两组各指标的差异;筛选出C-反应蛋白、红细胞沉降率与病程并得出诊断模型,绘制受试者工作特征(ROC)曲线,评估模型的诊断价值.结果两组C-反应蛋白、红细胞沉降率、白细胞计数、红细胞计数、血红蛋白、中性粒细胞、中性粒细胞百分比、单核细胞百分比及病程差异有统计学意义(P<0.05);通过Logistic回归,筛选出红细胞沉降率、白细胞计数、病程三项指标建立联合诊断模型,该模型ROC曲线下的面积(AUC)为0.802,敏感度为0.678,特异度为0.845.结论通过红细胞沉降率,白细胞计数,病程三项指标建立的联合诊断模型,能辅助鉴别化脓性与非化脓性脊柱感染,可更好地指导临床,及时开展针对性治疗改善患者预后.

关键词：化脓性脊柱感染 C-反应蛋白血沉病程诊断价值

Spatiotemporal Distribution and Epidemiological Characteristics of Hospital Admissions for Carbon Monoxide Poisoning in Guangdong,China,2013-2020

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Biomedical and Environmental Sciences 2022年第10期35卷 943-953页

作者： XIAO Bin ZHANG You Miao ZHOU Jing xu cheng dong HU Wei WEN Wei CHEN Jia Bin SUN cheng Ye National Institute for Occupational Health and Poison Control Chinese Center for Disease Control and PreventionBeijing 100050China Guangdong Province Hospital for Occupational Disease Prevention and Treatment Guangdong Provincial Key Laboratory of Occupational Disease Prevention and TreatmentGuangzhou 510300GuangdongChina School of Public Health Sun Yat-sen UniversityGuangzhou 510030GuangdongChina State Key Laboratory of Resources and Environmental Information System Institute of Geographic Science and Natural Resource ResearchChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100101China Commission Affairs Center of Health Commission of Guangdong Province Guangzhou 510060GuangdongChina

Objective This study aimed to determine the spatiotemporal distribution and epidemiological characteristics of hospital admissions for carbon monoxide poisoning(COP)in Guangdong,China,from 2013 to *** Data on age-and sex-specific numbers of hospital admissions due to COP in Guangdong(2013-2020)were *** temperatures were downloaded through the China Meteorological Data Sharing Service *** analyzed temporal trends through time series decomposition and used spatial autocorrelation analysis to detect spatial *** distributed lag nonlinear model was used to quantify the effects of *** There were 48,854 COP admissions over the study *** sex ratio(male to female)was1:*** concentration ratios(M)ranged from *** highest risk occurred in January(season index=3.59).Most cases were concentrated in the northern mountainous areas of Guangdong with high-high *** in the study region showed significant spatial autocorrelation,and the global Moran’s I value of average annual hospital admission rates for COP was 0.447(Pdong province showed significant temporal and spatial *** temperature was associated with a high risk of COP,and the influence had a lag lasting 7 days.

关键词： Carbon monoxide poisoning Hospitalization Distributed lag nonlinear model Spatialtemporal model

Experimental investigation on weak shock wave mitigation characteristics of flexible polyurethane foam and polyurea

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Defence Technology（防务技术） 2024年第1期31卷 179-191页

作者： Shiyu Jia cheng Wang Wenlong xu dong Ma Fangfang Qi State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China Institute for Advanced Technology Shandong UniversityJinan250061China

In recent years,explosion shock wave has been considered as a signature injury of the current military *** strong shock wave is lethal to the human body,weak shock wave can cause many more lasting *** investigate the protection ability and characteristics of flexible materials and structures under weak shock wave loading,the blast wave produced by TNT explosive is loaded on the polyurethane foam with the density of 200.0 kg/m3(F-200)and 400.0 kg/m3(F-400),polyurea with the density of 1100.0 kg/m^(3)(P-1100)and structures composed of the two materials,which are intended for individual *** results indicate that the shock wave is attenuated to weak pressure disturbance after interacting with the flexible materials which are not *** shock wave protective capability of single-layer materials is dependent on their thickness,density and microscopic *** overpressure,maximum pressure rise rate and impulse of transmitted wave decrease exponentially with increase in sample *** the same thickness,F-400 provides better protective capability than F-200 while P-1100 shows the best protective capability among the three *** this study,as the materials are not destroyed,F-200 with a thickness more than10.0 mm,F-400 with a thickness more than 4.0 mm,and P-1100 with a thickness more than 1.0 mm can attenuate the overpressure amplitude more than 90.0%.Further,multi-layer flexible composites are *** layer layouts of designed structures and layer thickness of the single-layer materials can affect the protective *** the research range,the structure in which polyurea is placed on the impact side shows the optimal shock wave protective performance,and the thicknesses of polyurea and polyurethane foam are 1.0 mm and 4.0 mm *** overpressure attenuation rate reached maximum value of 93.3%and impulse attenuation capacity of this structure are better than those of s

关键词： Free-field explosion Weak shock wave mitigation Polyurea Polyurethane foam Multi-layered composites

Lightweight innovation ADIs help development of renewable energy and new technology industries in China

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China Foundry 2024年第5期21卷 507-515页

作者： Qi-dong Yan xu-dong Gong Wen-bang Gong Jin-cheng Liu ADI Committee of China Foundry Association Beijing 100000China Yuzhou Henglilai New Materials Co. Ltd.Xuchang 452570HenanChina Kunshan Changjian Foundry Industry Co.Ltd. Kunshan 215311JiangsuChina School of Mechanical Engineering and Automation Wuhan Textile UniversityWuhan 430200China WFO Ferrous Metals Commission Shenyang 110022China

The world is undergoing profound changes in energy and *** are vigorously developing new sustainable energy sources and *** energy sources encompass various technologies such as wind turbines,solar energy,nuclear energy,and ***,emerging technology fields include new energy vehicles,robots,and artificial intelligence devices,among *** renewable energy industries and implementation of new technologies necessitate the development and adoption of new equipment and *** ductile iron(ADI)is renowned for its unique microstructure and superior *** utilizing ADI,lightweight and innovative castings can be designed to not only reduce weight but also save energy and decrease *** importantly,these castings enhance the efficiency and reliability of new energy equipment and emerging technology *** paper describes the development,applications,and future prospects of lightweight and innovative ADI castings within sectors such as solar photovoltaic(PV),wind power generation,industry robots,and trucks in China.

关键词： lightweight ADI renewable energy emission reduction