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Yield Vertices for Symmetric Slip on {110}<111> and Asymmetric Slip on {112}<111> Systems

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Journal of Materials Science & Technology 2001年第6期17卷 605-609页

作者： Zhiyong CHEN, Xinming ZHANG, churning liu, Zhuoping ZHOU and Yang YANG Department of Materials Science and Engineering, Central South University, Changsha 410083, China Saiyi LI Department of Metallurgy and Materials Engineering, Ka Dept. of Mat. Sci. and Eng. Central South Univ. Changsha 410083 China

The single crystal yield surfaces (SCYS) of bcc metals for symmetric slip on {110} (111) and asymmetric slip on {112} (111) systems have been analyzed and deduced. The complete SCYS have been derived when their critical resolved shear stresses (CRSS) are specified in a particular case (such as for Mo metal). The results showed that there are 600 stress states that can be classified into 35 groups according to the crystal symmetry. Each group activates eight, six or five {110} (111) and {112} (111) slip systems depending on crystallographically nonequivalent slip systems groups. Among all these stress states, three groups activate eight systems, there are 24 stress states; four groups activate six systems, there are 48 ones; the remaining twenty-eight groups activate five systems, there are 528 ones. In this case, the fraction of vertices for which there is slip ambiguity (more than five active systems) is reduced considerably compared with pure {110} (111) slip.

关键词： 110 and Asymmetric Slip on Systems

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冲击载荷下退火纯铜绝热剪切变形行为的研究

热加工工艺 2019年第22期48卷 19-22页

作者：张辉王仁可陈志永刘楚明中南大学材料科学与工程学院

采用金相显微观察、显微硬度测试、电子背散射衍射(EBSD)测试,研究了冲击载荷下退火纯铜绝热剪切变形后的微观结构以及显微织构特征。结果表明:在高应变率下,纯铜应力随应变增大而增大,表现出明显的的加工硬化效应。绝热剪切带很容易与... 详细信息

采用金相显微观察、显微硬度测试、电子背散射衍射(EBSD)测试,研究了冲击载荷下退火纯铜绝热剪切变形后的微观结构以及显微织构特征。结果表明:在高应变率下,纯铜应力随应变增大而增大,表现出明显的的加工硬化效应。绝热剪切带很容易与基体区分。剪切带内部显微硬度远高于剪切带外部区域。剪切带内部形成纳米级的超细晶。剪切区域内部晶体的方向平行于宏观剪切方向,晶体的{111}面以及{100}面平行于宏观剪切面。旋转动态再结晶可在剪切带内发生。

关键词：绝热剪切带显微硬度微观组织旋转动态再结晶

Influence of vibration on the lubrication effect of a splash-lubricated gearbox

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第4期25卷 324-339页

作者： Yi liu Kailin ZHANG Shuai SHAO Hongxu XIANG Zhijian YE State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong UniversityChengdu 610031China

In this study,we investigate the effect of rail vibrations on the lubrication and efficiency of a splash-lubricated gearbox;specifically,the gearbox of a rail-transit vehicle.A high-fidelity 3D numerical model of the gearbox in a moving reference system is described,as well as computational fluid dynamics(CFD)simulations of the gearbox with different vibration *** effects of rotational speed,oil-immersion depth,and different oil-injection volume rates on lubrication and efficiency are *** propose a method of evaluating the internal lubrication condition of a splash-lubricated gearbox and quantitatively compare the effects of different operating parameters on lubrication and ***,our experiment to verify the feasibility of the simulation method is *** results show that with vibration,the churning loss and oil supply for the bearings are significantly higher than those under static *** addition,among different vibrational directions,lateral vibration has the greatest influence on the lubrication condition and efficiency of the *** the studied railway-vehicle gearbox,the best lubrication condition is achieved at a rotational speed of 1600 r/min and an oil-immersion depth of two times the tooth height(***).Rotational speed is the operating parameter that has the most significant effect on the lubrication and efficiencyofthegearbox.

关键词： Comprehensive lubrication evaluation churning loss Moving reference system Splash lubrication Vibrational excitation Gearbox

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“续论”与对外汉语动结式的学习

广东外语外贸大学学报 2018年第3期29卷 21-28页

作者：刘丽王初明广东外语外贸大学英语教育学院广州510420 广东外语外贸大学外国语言学与应用语言学研究中心广州510420

通过有声思维和即时访谈的方法,深入探究读后续写促进学习汉语二语动结式的心理过程。两名在华留学生参与了此项质性研究。结果显示,读物中高频出现的动结式结构有助于促进续作中动结式的正确使用;续作在语言、篇章结构和连贯性方面跟... 详细信息

通过有声思维和即时访谈的方法,深入探究读后续写促进学习汉语二语动结式的心理过程。两名在华留学生参与了此项质性研究。结果显示,读物中高频出现的动结式结构有助于促进续作中动结式的正确使用;续作在语言、篇章结构和连贯性方面跟原作产生了明显的拉平效应;回读是拉平效应产生的主要途径。研究结果为对外汉语中的语言难点教学提供了启示。

关键词：读后续写动结式拉平效应

Development and Validation of a Prognostic Risk Score System for COVID-19 Inpatients:A Multi-Center Retrospective Study in China

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Engineering 2022年第1期8卷 116-121页

作者： Ye Yuan Chuan Sun Xiuchuan Tang Cheng Cheng Laurent Mombaerts Maolin Wang Tao Hu Chenyu Sun Yuqi Guo Xiuting Li Hui Xu Tongxin Ren Yang Xiao Yaru Xiao Hongling Zhu Honghan Wu Kezhi Li Chuming Chen Yingxia liu Zhichao Liang Zhiguo Cao Hai-Tao Zhang Ioannis Ch.Paschaldis Quanying liu Jorge Goncalves Qiang Zhong Li Yan School of Artificial Intelligence and Automation Huazhong University of Science and TechnologyWuhan 430074China School of Mechanical Science and Engineering Huazhong University of Science and TechnologyWuhan 430074China Luxembourg Centre for Systems Biomedicine University of LuxembourgBelval L-4367Luxembourg Department of Plant Sciences University of CambridgeCambridge CB21TNUK Department of Emergency Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China AMITA Health Saint Joseph Hospital Chicago ChicagoIL 60657USA Department of Anesthesiology Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China Huazhong University of Science and Technology-Wuxi Research Institute Wuxi 214174China Division of Cardiology Department of Internal MedicineTongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China Institute of Health Informatics University College LondonLondon NW12DAUK Department of Biomedical Engineering Southern University of Science and TechnologyShenzhen 518055China Department of Infectious Diseases Shenzhen Key Laboratory of Pathogenic Microbiology and ImmunologyNational Clinical Research Center for Infectious DiseaseThe Third People’s Hospital of Shenzhen(Second Hospital Affiliated with the Southern University of Science and Technology)Shenzhen 518055China Department of Electrical and Computer Engineering&Division of Systems Engineering&Department of Biomedical Engineering Boston UniversityBostonMA 02215USA

Coronavirus disease 2019(COVID-19)has become a worldwide *** patients of COVID-19 suffer from a high mortality rate,motivating the development of convenient and practical methods that allow clinicians to promptly identify high-risk ***,we have developed a risk score using clinical data from 1479 inpatients admitted to Tongji Hospital,Wuhan,China(development cohort)and externally validated with data from two other centers:141 inpatients from Jinyintan Hospital,Wuhan,China(validation cohort 1)and 432 inpatients from The Third People’s Hospital of Shenzhen,Shenzhen,China(validation cohort 2).The risk score is based on three biomarkers that are readily available in routine blood samples and can easily be translated into a probability of *** risk score can predict the mortality of individual patients more than 12 d in advance with more than 90%accuracy across all ***,the Kaplan-Meier score shows that patients can be clearly differentiated upon admission as low,intermediate,or high risk,with an area under the curve(AUC)score of *** summary,a simple risk score has been validated to predict death in patients infected with severe acute respiratory syndrome coronavirus 2(SARS-CoV-2);it has also been validated in independent cohorts.

关键词： COVID-19 Risk score Mortality risk prediction

Investigations on lubrication characteristics of high-speed electric multiple unit gearbox by oil volume adjusting device

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2022年第12期23卷 1013-1026页

作者： Shuai SHAO Kai-lin ZHANG Yuan YAO Yi liu Jun GU State Key Laboratory of Traction Power Southwest Jiaotong UniversityChengdu 610031China Suzhou shonCloud Engineering Sofiware Co.Ltd. Suzhou 215100China

In this paper,a numerical simulation model of the flow field in a gearbox with an oil volume adjusting device is established for the first time to study its influence on the lubrication characteristics of a high-speed electric multiple unit(EMU)*** moving particle semi-implicit(MPS)method is used to numerically simulate the internal flow field of the gearbox of the high-speed EMU under working *** effects of the velocity of the high-speed EMU,the immersion depth,and the oil sump temperature on the power loss of the gears and the lubricant quantity of each bearing are studied and provide an effective tool for the quantitative evaluation of the lubrication characteristics of the *** lubrication characteristics of the gearbox under different working conditions are studied when the oil volume adjusting device is closed and *** results show that the oil volume adjusting device mainly changes the amount of lubricant stirred by the output gear by changing the flow rate of lubricant from the cavity pinion(Cavity P)to the cavity gear(Cavity G),and thus affects the power loss of gears and the lubricant quantity of each bearing.

关键词： High-speed electric multiple unit(EMU) Splash lubrication Mesh-free moving particle semi-implicit(MPS)method Bearing lubrication churning power loss Oil volume adjusting device

行星轮系周转运动过程中的润滑油液分布与搅油损耗研究

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机械传动 2024年第9期48卷 10-17页

作者：陈慧潇师陆冰职彦锋颜世铛丁昊昊裴帮刘忠明王文健郑机所(郑州)传动科技有限公司河南郑州450001 郑州机械研究所有限公司河南郑州450001 西南交通大学摩擦学研究所四川成都610031

为探究行星齿轮传动系统飞溅润滑行为,基于移动粒子半隐式(Moving Particle Semi-implicit,MPS)方法建立了行星轮系飞溅润滑仿真模型,并对其进行了试验验证;研究了行星轮系周转运动过程中的减速器内部油液分布特征、轮齿啮合区润滑油液... 详细信息

为探究行星齿轮传动系统飞溅润滑行为,基于移动粒子半隐式(Moving Particle Semi-implicit,MPS)方法建立了行星轮系飞溅润滑仿真模型,并对其进行了试验验证;研究了行星轮系周转运动过程中的减速器内部油液分布特征、轮齿啮合区润滑油液粒子数量以及各旋转部件搅油损耗的变化规律。研究结果表明,行星轮系周转运动过程中,减速器内部可划分为油池区、拖拽区和贫油区3个区间;行星轮渐次通过各区间过程中,不同啮合区域内油液粒子数量以及各部件搅油损耗力矩值均呈现周期性变化规律。其中,内啮合区与外啮合区润滑油液粒子数量在行星轮运行至油池区时达到峰值,并均在进入贫油区后迅速下降至最小值;行星轮搅油损耗力矩在进入油池区后急剧上升至峰值,在进入拖拽区后持续下降直至进入贫油区后稳定在极低水平;而行星架搅油力矩在某一行星轮进入油池区域时急剧下降,在该行星轮进入拖拽区且下一行星轮未进入油池区时快速回升。在整个周转周期内,太阳轮搅油损耗较小且变化趋势较为平缓。行星轮系总的搅油损耗功率中,3个行星轮总搅油损耗功率占比约为60%,其次是行星架,太阳轮占比最少。

关键词： MPS 行星轮系飞溅润滑油液分布搅油损耗

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林可霉素联合利巴韦林治疗小儿肺炎的临床疗效及安全性研究

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今日药学 2019年第4期29卷 260-262页

作者：范翠琼杨水源林冠文游楚明童艳丽刘蕴婷广东省第二人民医院医院感染管理科广东广州510317 广东省第二人民医院药学部广东广州510317 广东省第二人民医院儿科广东广州510317

目的探讨林可霉素联合利巴韦林治疗小儿肺炎的临床疗效及安全性。方法选取某院2016年7月～2018月7月的106例小儿肺炎进行研究,根据患儿病情的情况分为联合治疗组和单纯治疗组各53例,单纯治疗组采用利巴韦林治疗,联合治疗组在单纯治疗组... 详细信息

目的探讨林可霉素联合利巴韦林治疗小儿肺炎的临床疗效及安全性。方法选取某院2016年7月～2018月7月的106例小儿肺炎进行研究,根据患儿病情的情况分为联合治疗组和单纯治疗组各53例,单纯治疗组采用利巴韦林治疗,联合治疗组在单纯治疗组的基础上进行林可霉素治疗,治疗1周时间,观察两组患儿的临床疗效、肺功能(FEV1/FVC、PEF和MBC)、炎性指标(IL-2、IL-6)及不良反应。结果联合治疗组的总有效率(96.4%)明显高于单纯治疗组(78.6%),有统计学意义(P<0.05);联合治疗组的FEV1/FVC、PEF和MBC水平比单纯治疗组明显增高(P<0.05);联合治疗组的IL-2、IL-6水平比单纯治疗组明显降低(P<0.05);两组患儿均无恶心、头疼、口干、嗜睡等药物不良反应。结论林可霉素联合利巴韦林治疗小儿肺炎可以有效改善患儿的肺功能,消除炎性反应,可以用于小儿肺炎的治疗。

关键词：肺炎林可霉素利巴韦林临床疗效炎性反应

Development of an analytical model to estimate the churning losses in high-speed axial piston pumps

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Frontiers of Mechanical Engineering 2022年第2期17卷 165-175页

作者： Qun CHAO Jianfeng TAO Chengliang liu Zhengliang LI State Key Laboratory of Mechanical System and Vibration School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Fluid Power and Mechatronic Systems School of Mechanical EngineeringZhejiang UniversityHangzhou 310027China Liyuan Hydraulic(Suzhou)Co. Ltd.Suzhou 215131China

The axial piston pumps in aerospace applications are often characterized by high-speed rotation to achieve great power density. However, their internal rotating parts are fully immersed in the casing oil during operation, leading to considerable churning losses (more than 10% of total power losses) at high rotational speeds. The churning losses deserve much attention at the design stage of high-speed axial piston pumps, but accurate analytical models are not available to estimate the drag torque associated with the churning losses. In this paper, we derive the analytical expressions of the drag torque acting on the key rotating parts immersed in oil, including the cylinder block and the multiple pistons in a circular array. The calculated drag torque agrees well with the experimental data over a wide range of rotational speeds from 1500 to 12000 r/min. The presented analytical model provides practical guidelines for reducing the churning losses in high-speed axial piston pumps or motors.

关键词： axial piston pump rotating parts high rotational speed churning losses drag torque