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Mechanistic study of ammonium-induced corrosion of AZ31 magnesium alloy in sulfate solution

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Journal of Materials Science & Technology 2020年第19期54卷 1-13页

作者： Hui Pan Liwei Wang yi Lin feng Ge Kang Zhao xin Wang Zhongyu Cui College of Electromechanical Engineering Qingdao UniversityQingdao 266071China School of Materials Science and Engineering Ocean University of ChinaQingdao 266100China

The influence of NH4+ions on the corrosion behavior of AZ31 magnesium alloy was investigated by immersion test,hydrogen evolution,electrochemical methods and morphology *** results demonstrate the acceleration effect of NH4+on corrosion of AZ31 magnesium alloy due to the disruption of protective MgO film in NH4+-containing *** loose and cracked corrosion products of AZ31 magnesium alloy in NH4+-containing solutions are mainly composed of(Mg0.833Al0.167)(OH)2(CO3)0.083·0.75H2O and Mg5(CO3)4(OH)2·*** the NH4+concentration is lower than 0.01 M,knife-cut like corrosion occurs in some active area of the surface due to the partial dissolution of MgO *** the NH4+concentration is increased to 0.1 M,the MgO layer is completely disrupted,resulting in the occurrence of uniform *** cathodic and anodic reactions are accelerated by NH4+ions,while the effect of original pH values on the reaction kinetics can be neglected in NH4+-containing solutions.

关键词： Magnesium alloy Ammonium Corrosion kinetics Knife-cut like corrosion

考虑参考价格效应与消费者异质性的灰市系统定价决策

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管理工程学报 2025年第2期39卷 234-247页

作者：冯颖何文豪宋欣张炎治刘满芝中国矿业大学经济管理学院

考虑高价市场和灰市间的双向不对称参考价格效应以及消费者购买行为异质性,本文研究由一个制造商和一个独立的第三方灰市投机者构成的灰市系统定价决策问题。基于消费者对授权渠道是否忠诚,本文将消费者分为策略型和忠诚型两类,并分别... 详细信息

考虑高价市场和灰市间的双向不对称参考价格效应以及消费者购买行为异质性,本文研究由一个制造商和一个独立的第三方灰市投机者构成的灰市系统定价决策问题。基于消费者对授权渠道是否忠诚,本文将消费者分为策略型和忠诚型两类,并分别构建了无/有参考价格效应下的Stackelberg博弈模型。当系统取得内点均衡时,研究发现:在无参考价格效应的基准情形下,消费者对灰色产品的偏好度上升且策略型消费者比例增加,这会直接导致灰色产品价格上涨,进而间接导致低价产品价格上涨、需求下降。此时,高价市场和灰市需求以及制造商收益变化均存在与消费者对低价市场支付意愿相关的阈值,这些变化均源于消费者的低价市场支付意愿对灰市投机空间的直接影响。在考虑参考价格效应的情形下,各均衡结果随上述两个参数的整体变化趋势与无参考价格效应时的情形相同,但此时高价市场和灰市需求及制造商收益变化的阈值发生变化。参考价格效应强度的增加及收益-损失比值的增大,均会提升低价产品和灰色产品的价格、降低低价市场的需求和提高高价市场的需求,且灰市需求及制造商收益变化不定。参考价格效应会对灰色产品价格、灰市需求和高价市场需求产生直接影响,制造商和灰市投机者并非一定受益或受损。参考价格效应对双方收益的影响与消费者对低价市场的支付意愿密切相关。

关键词：灰市定价决策消费者异质性参考价格效应

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Fabrication of Humidity Sensors Based on Laser Scribed Graphene Oxide/SnO Composite Layers

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Chinese Journal of Structural Chemistry 2020年第11期39卷 1949-1957页

作者： LI xin feng Wen-Dou ZHANG Xiang-xin WANG Wei CHEN Su-Jing ZHANG yi-Ning College of Chemistry and Materials Science Fujian Normal UniversityFuzhou 350007China Key Laboratory of Optoelectronic Materials Chemistry and Physics Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China

Humidity sensors have been widely applied to detect environment humidity in various fields. However, most of humidity sensors cannot provide performance needed for high sensitivity and fast response. We report one type of capacitive-type humidity sensors composed of laser-scribed graphene(LSG) as sensing electrodes and graphene oxide/tin dioxide(GO/SnO2) as a sensing layer. The LSG is reduced graphene oxide(rGO) electrodes resulted from selective reducing of GO within a GO/SnO2 composite layer by laser scribing method, and the sensing layer is the un-scribed GO/SnO2 composite. The sensor fabrication is a one-step process which is facile and cost-efficient. When a mass ratio of GO:SnO2 in the composite reaches 1:1, the humidity sensor(named as LSG-GS1) has the best properties than other ratios, which exhibits high sensitivity in the range of 11%~97% relative humidity(RH). In addition, the LSG-GS1 also has very quick response/recovery time(20 s for adsorption and 18 s for desorption) when RH changes from 23% to 84%, and very good stability after monitoring for 41 days. Such excellent performances of the humidity sensor can be attributed to synergistic effect of SnO2 and GO within the composite layer.

关键词： humidity sensor tin dioxide graphene laser scribed

Pancreaticoduodenectomy for borderline resectable pancreatic head cancer with a modified artery-first approach technique

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Hepatobiliary & Pancreatic Diseases International 2017年第2期16卷 215-221页

作者： Min Wang Hang Zhang feng Zhu feng Peng xin Wang Ming Shen Ren-yi Qin Department of Pancreatic-Biliary Surgery Affiliated Tongji Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan 430030 China

BACKGROUND： The treatment of borderline resectable pancreatic head cancer（BRPHC） is still controversial and challenging. The artery-first approaches are described to be the important options for the early determination. Whether these approaches can achieve an increase R0 rate, better bleeding control and increasing long-term survival for BRPHC are still controversial. We compared a previously reported technique, a modified artery-first approach（MAFA）, with conventional techniques for the surgical treatment of ***： A total of 117 patients with BRPHC undergone pancreaticoduodenectomy（PD） from January 2013 to June 2015 were included. They were divided into an MAFA group（n=78） and a conventional-technique group（n=39）. Background characteristics, operative data and complications were compared between the two ***： Mean operation time was significantly shorter in the MAFA group than that in the conventional-technique group（313 vs 384 min; P=0.014）; mean volume of intraoperative blood loss was significantly lower in the MAFA group than that in the conventional-technique group（534 vs 756 m L; P=0.043）; and mean rate of venous resection was significantly higher in the conventional-technique group than that in the MAFA group（61.5% vs 35.9%; P=0.014）. Pathologic data, early mortality and morbidity were not different significantly between the two ***： MAFA is safe, simple, less time-consuming, less intraoperative blood loss and less venous resection, and therefore, may become a standard surgical approach to PD for BRPHC with the superior mesenteric vein-portal vein involvement but without superior mesenteric artery invasion.

关键词： pancreatic head cancer pancreaticoduodenectomy borderline resectable

Solidification and heat transfer of molten steel slag particles during air quenching process

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Journal of Iron and Steel Research International 2023年第9期30卷 1834-1842页

作者： Wen-feng Gu Jiang Diao Rui-xin Hu Wen-sun Ge Wen-feng Tan Hong-yi Li Bing Xie College of Materials Science and Engineering Chongqing UniversityChongqing 400044China Chongqing Key Laboratory of Vanadium–Titanium Metallurgy and Advanced Materials Chongqing UniversityChongqing 400044China Institute of Materials Engineering Technology Pangang Group Research Institute Co.Ltd.Panzhihua 617000SichuanChina

In order to effectively utilize the resources and energy of molten steel slag,the variation of precipitation phase and specific heat of air quenched steel slag(AQSS)particles during continuous cooling process was investigated by FactSage and thermogravimetry differential scanning *** cooling and solidification process of molten AQSS particles was simulated by *** microstructure changes in AQSS particles in solidification process were analyzed using an ultrahigh temperature laser confocal microscope and a scanning electron *** results indicated that in the cooling process of molten AQSS particles,the precipitation of Ca_(2)Fe_(2)O_(5) resulted in the largest change of specific *** the condition of slow cooling,the cooling rate is more obviously affected by specific *** the initial air velocity was 300 m s^(-1),there was the highest temperature difference in AQSS particles during cooling *** is more,the compactness of the boundary region of AQSS particles was obviously better than that of its central region.

关键词： Specific heat Air quenched steel slag Cooling Solidification Microstructure change

Simulation of gamma minitype reference radiation for calibration of personal dosimeter

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Nuclear Science and Techniques 2020年第1期31卷 112-122页

作者： yi-xin Liu yi-Kun Qian Zhi-Qiang Chen Biao Wei Peng feng Ben-Jiang Mao Department of Engineering Physics Tsinghua UniversityBeijing 100084China Institute of Nuclear Physics and Chemistry China Academy of Engineering PhysicsMianyang 621999China Key Laboratory of Optoelectronics Technology and System Ministry of EducationChongqing UniversityChongqing 400044China

An investigation using Monte Carlo simulation on a minitype reference radiation(MRR) for the calibration of gamma personal dosimeters is reported. The distributions of dose rate and scattering gamma spectrum are the main simulation objects with the variable physical structures of MRR and the dosimeters as parameters that are to be calibrated. Further, the influences on the reference radiation caused by these parameters are analyzed in *** work provides a theoretical basis for better understanding of MRR used for calibration of gamma personal dosimeters. This analysis can help in the development of a calibration technology for such tools based on MRR.

关键词： Gamma personal dosimeter Minitype reference radiation Monte Carlo simulation Calibration

Spectral and statistical analysis of bow wave breaking characteristics of KCS ship

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Journal of Hydrodynamics 2024年第4期36卷 593-608页

作者： xin-yi Li feng-jun Bao Jian-hua Wang De-cheng Wan Jian Xu Computational Marine Hydrodynamics Lab(CMHL) School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China Ningbo Pilot Station Ningbo Dagang Pilotage Co.Ltd.Ningbo315100China China Shipbuilding Ninth Design and Research Institute Engineering Co. Ltd.Shanghai200063China

Bow wave breaking is a common phenomenon during ship navigation,especially at a high speed,involving complex physical mechanism such as interface mixing,air entrainment,and jet *** study uses the delayed detached eddy simulation(DDES)turbulence model on the OpenFOAM platform to simulate flow around a KRISO Container Ship(KCS)model for a Froude number of 0.35,examining trim angles of 0°,0.5°,1°.This paper analyzes the statistical and power spectral density(PSD)characteristics of bow wave *** analysis shows root mean square(rms)and mean difference between top and bottom views indicate wave *** the trim angle increases,peaks of rms in the bottom view become much higher than that in the top view,reaching 38%at 1°.PSD analysis reveals that resistance and wave height periods differ by no more than 5%,with small-scale structures like jetting and splashing causing non-dominant periodic and high-frequency wave height variations.

关键词： Bow wave breaking KRSIO Container Ship(KCS) statistical characteristics analysis spectral analysis

Study on the Reservoir Water Quality Change Rule in Northern China

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Journal of Harbin Institute of Technology(New Series) 2013年第4期20卷 26-30页

作者： Ling-Yan feng Li-xin Li yi-xing Yuan School of Municipal and Environmental Engineering Harbin Institute of Technology School of Environment and Chemical Engineering Heilongjiang University of Science and Technology

Water quality index of reservoir source water were tracked during three years in a north frigid area,the effect on supplied water quality was also *** on the analysis of the monitoring data during the same season,the reservoir source water had typical and seasonal variation characteristics that was divided into four periods including the icebound period,spring period(or peach blossom period),stable period in summer and autumn and winter *** icebound period was charactered by the typical low temperature and turbidity,pH and oxygen consumption decreased gradually showed that the gradually anaerobic trend existed in the *** May as the reservoir completely thawed,upstream water inflow and the total pollutant in the reservoir gradually increased,but the bottom of reservoir bottom was stable in the anaerobic state *** state completely disappeared,various index increased significantly in the middle of *** water had high chroma characteristics,chroma and turbidity increased significantly in the summer and autumn(7-11months),but stability of water quality was poor because of *** reservoir gradually froze after the middle of November and the flow of water *** peak of chroma appeared a month later than the water *** to the water turbidity was low,and the floc was small and light,the conventional water purification process design based on removal of turbidity achieved removal of chroma through a lot dosing of coagulant.

关键词： reservoir source water in frigid area quality of water supply ehroma low temperature and low turbidity

Influence of angle’s ranges for recording an X-ray fluorescence hologram on reconstructed atomic images

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Nuclear Science and Techniques 2004年第3期15卷 160-165页

作者： XIEHong-Lan CHENJian-Wen GAOHong-yi ZHUHua-feng LIRu-xin XUZhi-Zhan ShanghaiInstituteofOpticsandFineMechanics theChineseAcademyofSciencesShanghai201800

X-ray fluorescence holography (XFH) is a novel method for three-dimensional (3D) imaging of atomic structure. Theoretically, in an XFH experiment, one has to measure the fluorescence energy on a spherical surface to get well-resolved 3D images of atoms. But in practice, the experimental system arrangement does not allow the meas- urement of the fluorescent intensity oscillations in the full sphere. The holographic information losses because of the limited sampling range (less than 4π) will directly result in defective reconstructed atomic images. In this work, the atomic image of a Fe single crystal (001) was reconstructed by numerically simulating X-ray fluorescence holograms of the crystal at different recording angle’s ranges and step lengths. Influences of the ranges of azimuth angles and polar angles and the step length of polar angles on the reconstructed atomic images were discussed.

关键词： X射线荧光全息摄影晶体结构傅立叶变换原子图像重建