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On the deformation behavior of heterogeneous microstructure and its effect on the mechanical properties of die cast AZ91D magnesium alloy

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Journal of magnesium and Alloys 2022年第7期10卷 1981-1993页

作者： Mengwu Wu Yingying Hou Lin Hua huijuan ma Xiaobo Li Shoumei Xiong Hubei Key Laboratory of Advanced Technology for Automotive Components Wuhan University of TechnologyWuhan 430070China School of materials Science and Engineering Tsinghua UniversityBeijing 100084China

Both a conventional flow distributer and an improved one with a flow buffer were applied respectively during the high pressure die casting(HPDC)process,and samples of AZ91D magnesium alloy with different microstructure mainly consisting ofα-Mg grains,β-phase and porosities were obtained.According to the grain orientation analysis,the predominant deformation behavior inα-Mg grains was dislocation slip,supplemented by deformation twinning.Dislocation slip was more difficult to occur in the samples with the improved flow distributer on account of the fact that the size ofα-Mg grains in the microstructure was finer and more uniform.During the in situ tensile deformation test,cracks were observed to initiate from gas-shrinkage pore and island-shrinkage,and two main crack propagation mechanisms,porosity growth and coalescence were found accordingly.When the crack was in contact with theβ-phase,it would pass through and fracture the networkβ-phase,whereas bypass the islandβ-phase by detaching it from the surroundingα-Mg grains.Mechanical property tests showed that the samples with relatively more homogeneous microstructure would perform higher mechanical properties,which was the combined effect of matrixα-Mg grains,β-phase,and porosities.

关键词： magnesium alloy High pressure die casting Microstructure Deformation behavior Mechanical properties

Concise Strategies to Enhance the High-Rate Performance of Li_(3)VO_(4) Anodes:Cl Doping,Carbon Coating,and Spherical Architecture Design

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Transactions of Tianjin University 2023年第2期29卷 110-119页

作者： Zongping Zhang Jie Xu Dongmei Zhang huijuan ma Tao Li Ting Xiao Cunyuan Pei Shibing Ni College of materials and Chemical Engineering Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion MaterialsChina Three Gorges UniversityYichang 443002China Hubei Three Gorges Laboratory Yichang 443007China Analysis and Testing Center China Three Gorges UniversityYichang 443002China College of Electrical Engineering and New Energy China Three Gorges UniversityYichang 443002China

The safe operating voltage and low volume variation of Li_(3)VO_(4)(LVO)make it an ideal anode material for lithium(Li)-ion batteries.However,the insufficient understanding of the inner storage mechanism hinders the design of LVO-based electrodes.Herein,we investigate,for the first time,the Li-ion storage activity in LVO via Cl doping.Moreover,N-doped C coating was simultaneously achieved in the Cl doping process,resulting in synergistically improved reaction kinetics.As a result,the as-prepared Cl-doped Li_(3)VO_(4) coated with N-doped C(Cl-LVO@NC)electrodes deliver a discharge capacity of 884.1 mah/g after 200 cycles at 0.2 A/g,which is the highest among all of the LVO-based electrodes.The Cl-LVO@NC electrodes also exhibit high-capacity retention of 331.1 mah/g at 8.0 A/g and full capacity recovery after 5 periods of rate testing over 400 cycles.After 5000 cycles at 4.0 A/g,the discharge capacity can be maintained at 423.2 mah/g,which is superior to most LVO-based electrodes.The Li-ion storage activity in LVO via Cl doping and significant improvement in the high-rate Li-ion storage reported in this work can be used as references for the design of advanced LVO-based electrodes for high-power applications.

关键词： Li_(3)VO_(4) Cl doping New mechanisms High-rate Li-ion storage

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航空航天大型锻件质量与生产能耗检测方法

精密成形工程 2024年第3期16卷 16-31页

作者：马慧娟龚智昂胡志力华林武汉理工大学汽车工程学院现代汽车零部件技术湖北省重点实验室武汉430070 武汉理工大学汽车工程学院汽车零部件技术湖北省协同创新中心武汉430070 武汉理工大学汽车工程学院湖北省新能源与智能网联车工程技术研究中心武汉430070

锻造工艺作为航空航天领域生产制造企业至关重要的精密成形方法,被广泛应用于大飞机和火箭上多品种锻件的批量生产,但是对锻件质量要求很高,且锻造工艺能耗巨大,直接影响企业的经济效益,间接造成众多环境污染问题。为争取早日实现我国... 详细信息

锻造工艺作为航空航天领域生产制造企业至关重要的精密成形方法,被广泛应用于大飞机和火箭上多品种锻件的批量生产,但是对锻件质量要求很高,且锻造工艺能耗巨大,直接影响企业的经济效益,间接造成众多环境污染问题。为争取早日实现我国“双碳”目标以及持续推进制造业转型和能源结构调整的目标,亟需在保证锻件质量要求的基础上采取节能降耗措施。针对航空航天领域以铝合金材料为代表的大型锻件常见缺陷与核心质量要求,将锻造生产流程分解为原材料、备料、加热、锻压和锻后热处理5个主要环节,归纳总结了锻件缺陷及其产生原因和影响机制;系统阐明外观质量、力学性能、晶粒度/平均晶粒尺寸、断裂韧性、残余应力和抗腐蚀能力等质量要求的检测方法的研究现状,为铝合金等金属大型锻件的重要质量检测研究提供指导;同时,针对大型金属锻件锻造工艺能耗管控粗放的特点,从工厂层、装备层、产品层3个层面梳理能耗检测方法并提供提高能效的相关研究思路,为实现航空航天大型锻件节能降耗生产提供指导。在锻造行业高质低耗生产转型发展过程中,该理论方法在以铝合金为代表的大型金属锻件关键质量检测和生产能耗检测方面,具有一定的指导意义。

关键词：铝合金大型锻件缺陷质量检测能耗检测

A compact fluorescence/circular dichroism dual-modality probe for detection, differentiation, and detoxification of multiple heavy metal ions via bond-cleavage cascade reactions

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Chinese Chemical Letters 2021年第12期32卷 3876-3881页

作者： Junwei Chen Na Wang Hongjuan Tong Chao Song huijuan ma Yajun Zhang Feng Gao Huan Xu Wei Wang Kaiyan Lou State Key Laboratory of Bioengineering Reactor.Shanghai Key Laboratory of New Drug Design and Shanghai Key Laboratory of Chemical BiologySchool of PharmacyEast China University of Science & TechnologyShanghai 200237China School of Pharmacy Collaborative Innovation Center of Green Manufacturing Technology for Traditional Chinese Medicine in Shaanxi ProvinceShaanxi Institute of International Trade&CommerceXi'an 712046China Department of Pharmacology and Toxicology and BIO5 Institute University of ArizonaTucson AZ 85721-0207United States

Selective detection of multiple analytes in a compact design with dual-modality and theranostic features presents great challenges. Herein, we wish to report a coumarin-thiazolidine masked D-penicillamine based dual-modality fluorescent probe COU-DPA-1 for selective detection, differentiation, and detoxification of multiple heavy metal ions(Ag^(+), Hg^(2+), Cu^(2+)). The probe shows divergent fluorescence(FL)/circular dichroism(CD) responses via divergent bond-cleavage cascade reactions(metal ion promoted C-S cleavage and hydrolysis at two distinctive cleavage sites): FL “turn-off” and CD “turn-on” for Ag+(no hydrolysis), FL “turn-on” and CD “turn-off” for Hg^(+)(imine hydrolysis), and FL “self-threshold ratiometric” and CD “turn-off” for excess Cu^(2+)(lactone and imine hydrolysis), providing the first example of a fluorescence/CD dual-modality probe for multiple species with complimentary responses. Moreover, the bond-cleavage cascade reactions also lead to the formation of D-penicillamine heavy metal ion complexes for potential detoxification treatments.

关键词： Fluorescent probe Circular dichroism Heavy metal ions Dual-modality Detoxification Cascade reaction Divergent responses

军队医院抽组护理人员执行卫勤保障任务的现状与建议

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护理管理杂志 2024年第1期24卷 40-43,49页

作者：邓静马会娟牛爱芳王丹罗羽陆军军医大学护理学院重庆市400038

护理人员作为军队医院机动卫勤保障力量的重要组成部分,其抽组构成及能力水平直接影响卫勤保障任务的整体效能及总体质量。文章从军队医院抽组护理人员执行卫勤保障任务的原则、方法、选拔程序、人员能力和培训内容等方面综述现状及存... 详细信息

护理人员作为军队医院机动卫勤保障力量的重要组成部分,其抽组构成及能力水平直接影响卫勤保障任务的整体效能及总体质量。文章从军队医院抽组护理人员执行卫勤保障任务的原则、方法、选拔程序、人员能力和培训内容等方面综述现状及存在问题,并从顶层设计人员抽组的具体方案、科学创新人员抽组的方法手段、合理设置抽组人员的培训内容及方式等方面提出建议,旨在为提高军队医院抽组护理人员执行卫勤保障任务的效率与质量提供参考借鉴。

关键词：军队医院护理人员卫勤保障人员抽组

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睡眠纺锤波的影响因素分析

临床神经病学杂志 2024年第2期37卷 102-106页

作者：马慧娟刘春燕王桂芳王丽北京社会管理职业学院(民政部培训中心) 国家康复辅具研究中心附属康复医院神经内科102600 首都医科大学宣武医院神经内科脑功能疾病调控治疗北京市重点实验室新乡市中心医院儿科北京理工大学医学技术学院

目的睡眠纺锤波有促进认知的功能,本文探讨睡眠纺锤波的影响因素,为临床干预和调节纺锤波,进而改善睡眠和认知提供佐证。方法对50例睡眠质量不佳的患者使用多导睡眠监测系统进行整夜睡眠呼吸监测,得到睡眠结构相关参数、脑电功率谱、心... 详细信息

目的睡眠纺锤波有促进认知的功能,本文探讨睡眠纺锤波的影响因素,为临床干预和调节纺锤波,进而改善睡眠和认知提供佐证。方法对50例睡眠质量不佳的患者使用多导睡眠监测系统进行整夜睡眠呼吸监测,得到睡眠结构相关参数、脑电功率谱、心血管及呼吸功能的生理参数。分别计算各参数以及年龄、性别与非快速眼动睡眠(NREM)Ⅱ期纺锤波指数及特征(频率、时长和波幅)的相关性。其中庞加莱图中的SD1代表副交感神经活性的正指标,SD2代表交感神经活性的逆指标;脉搏传导时间(PTT)下降指数代表血管交感神经稳定性。结果SD1(β=-0.512,P<0.05)和PTT下降指数(β=-0.271,P<0.05)与纺锤波指数分别呈负相关,SD2与纺锤波指数呈正相关(β=0.474,P<0.05)。睡眠期变化指数、NREMⅠ期占比和皮质EEG微觉醒指数均与纺锤波指数呈低度负相关(r=-0.316,r=-0.359,r=-0.326;均P<0.05)。年龄与纺锤波指数呈负相关(β=-0.422,P<0.05)。深睡期δ功率与纺锤波幅度呈正相关(β=0.65,P<0.001)。未发现性别与纺锤波有相关性。结论睡眠纺锤波的产生依赖于良好的睡眠及稳定的自主神经。其与认知相关,能反映神经突触连接的强度,这为临床干预和调节纺锤波提供了佐证,也为评价认知和大脑功能提供了新的生理指标。

关键词：睡眠纺锤波自主神经庞加莱图多导睡眠监测脉搏传导时间下降指数

Sugar, energy content and added sugar labelling of beverages in Beijing, China: a cross-sectional study

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Sugar, energy content and added sugar labelling of beverages...

New insights into the immunopathogenesis of systemic lupus erythematosus： the role of T follicular helper cells

中国营养学会第十五届全国营养科学大会

作者： Jing Wen huijuan ma Xiaoxuan Zhang Xueqian Yin Ruoyu Zhou Junbo Wang Department of Nutrition and Food Hygiene School of Public Health Peking University

This study aimed to investigate the sugar, energy content of beverages and how added sugar was labelled in main supermarkets in Beijing, China. Methods A cross-sectional study was conducted in 26 supermarkets from October to December in 2019 in Beijing, China. Type(imported/domestic), serving size, carbohydrate, added sugar and energy content of the beverages were extracted from product package and nutrition label by snapshotting all the beverages with nutrition label for sale. Beverages without added sugar content on the package, we used carbohydrate content as a replacement and for those beverages with same formulation but different in size, we only recorded once. The guideline on front-of-pack colorcoded labelling for drinks released by the Food Standards Agency in the UK(sugars—red/high>13.5 g/portion or >11.25 g/100 mL) and the recommendation for daily free sugar intake from the World Health Organization(WHO, 25 g) were used to determine the success rate of sugar content. The non-parametric test was used to investigate the differences of sugar and energy content among different kinds of beverages. Chisquare test was performed to analyze the rate of added sugar labelling and overstandard sugar content between 2 types of beverages. Results A total of 1587 beverages were included in our study, which were divided into 2 types with 612 imported beverages and 975 domestic beverages. According to the Chinese General Standard for Beverage(GB/T 10789-2015), beverages were divided into 8 categories including 631 fruit/vegetable juices and beverages, 264 protein beverages, 205 carbonated beverages, 165 tea beverages, 121 flavored beverages, 110 coffee beverages, 50 beverages for special uses and 41 botanical beverages. The median of sugar content and energy content of all included beverages was 9.0 g/100 mL and 42.1 kcal/100 mL. For the imported and domestic beverages, the median of sugar contents were 10.0 g/100 mL, 8.0 g/100 mL respectively, and the median of energy contents were 45.2 kcal/100 mL and 39.2 kcal/100 mL

关键词： Energy Added sugar Sugar-sweetened Beverages Nutrition label

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Chinese Medical Journal 2014年第19期127卷 3496-3502页

作者： ma huijuan Xia Changqing Wan Suigui Department of Hematology Xuanwu Hospital Capital MedicalUniversity Beijing 100053 China

Objective To review the development of T follicular helper （TFH） cells and their role in systemic lupus erythematosus （SLE） pathogenesis, the effect of dendritic cells （DCs） on TFH cells in SLE, as well as the potential use of TFH cells as a new therapeutic target in clinical practice. Data sources The data used in this review were retrieved mainly from the PubMed database （1989-2013）. The terms used in the literature search were ＂T follicular helper cells,＂＂systemic lupus erythematosus,＂ and ＂dendritic cells.＂ Study selection Relevant publications about the TFH cells development, the interaction between the TFH cells and the DCs, and the clinical applications of TFH cells were identified, retrieved, and reviewed. Results TFH cells, a novel distinct CD4＋ T cell subset, are specialized in providing help to B cells in the formation of germinal centers （GCs） and long-term protective humoral immune responses. The development of TFH cells from naive CD4＋ T cell is a multistep process. As the pivot of immunoregulation, DCs are indispensable for TFH cells generation. In addition to receptor-ligand interactions between TFH cells and DCs, the cytokines secreted by DCs are also necessary for TFH cell generation. TFH cell dysregulation has been implicated in the development of SLE. More evidence from animal models of SLE and SLE patients suggests that TFH cells are necessary for pathogenic autoantibody production. Therefore, therapeutically targeting TFH cells can be a promising approach to treat antibody-mediated autoimmune diseases including SLE. Conclusion TFH cells play a critical role in the pathogenesis of SLE, making them attractive therapeutic targets in clinical practice.

关键词： systemic lupus erythematosus T follicular helper cells dendritic cells autoantibodies

基于便携式骨龄检测仪对杭嘉湖地区儿童及青少年骨龄调查研究

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浙江医学 2024年第3期46卷 291-296,331页

作者：钱琦高铖铖徐宏亮曹黎明马慧娟浙江中医药大学附属第三医院放射科杭州310005 杭州市第一人民医院放射科德清县人民医院放射科平湖市中医院放射科浙江中医药大学附属第三医院儿科

目的基于便携式骨龄检测仪对杭嘉湖地区儿童及青少年骨龄情况进行调查研究,为该地区的骨龄评估方法提供参考。方法回顾性收集1054名杭嘉湖地区3~18岁儿童及青少年的X线骨龄图像,并对骨龄图像进行骨龄判读,分析男性、女性的骨龄发育与生... 详细信息

目的基于便携式骨龄检测仪对杭嘉湖地区儿童及青少年骨龄情况进行调查研究,为该地区的骨龄评估方法提供参考。方法回顾性收集1054名杭嘉湖地区3~18岁儿童及青少年的X线骨龄图像,并对骨龄图像进行骨龄判读,分析男性、女性的骨龄发育与生活年龄的差异及Greulich-Pyle图谱法(GP)、Tanner Whitehouse Ⅲ(TW3)计分法R系列(TW3-R)和C系列(TW3-C)两种以及《中国人手腕骨发育标准——中华05》法(中华05法)中的中华05-R系列、中华05-C系列5种骨龄评估方法的变化趋势,并对身高、BMI百分位数进行亚组分析。结果男性组≥3~0.05)。女性组从≥3~<5岁到≥13~<15岁的年龄段5种测评方法的结果差异均有统计学意义(均P<0.05)。5种骨龄评估方法所测骨龄与生活年龄的差值随年龄变化的趋势并无明显的性别差异。TW3-R系列在所有年龄段骨龄测量结果均比较接近实际生活年龄,中华05-C系列和TW3-C系列在中间层年龄段的骨龄测量结果更为准确。结论基于便携式骨龄检测仪的5种骨龄评价方法具有一定的准确度,但无法精确反映杭嘉湖地区儿童及青少年的骨骼发育实际情况,放射科医师需结合多种评估方式综合分析。

关键词：骨龄深度学习儿童青少年便携