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Mechanical property and anisotropy of as-extruded Mg-Zn-Y-Mn alloys with different volume fraction of long-period stacking ordered(LPSO)phase

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Journal of Rare Earths 2024年第12期42卷 2259-2269,I0003页

作者： Dahui Liang Mincong Chen Chuanqiang Li Zhipei Tong Yong dong dong bian School of Materials and Energy Guangdong University of TechnologyGuangzhou510006China Medical Research Institute Department of OrthopedicsGuangdong Provincial People's Hospital(Guangdong Academy of Medical Sciences)Southern Medical UniversityGuangzhou510080China

Effects of different volume fraction of long-period stacking ordered(LPSO)phase on the microstructure,mechanical property and anisotropy of the as-extruded Mg-xZn-yY-0.1Mn(x=1 wt%,2 wt%,4 wt%and y=2 wt%,4 wt%,8 wt%)alloys were studied by an optical microscope,a scanning electron microscope,texture analysis,a transmission electron microscope and tensile *** results reveal that the volume fraction of LPSO phase increases from ZW12 to ZW24 to ZW48 alloys with the elevating Zn and Y content but constant Y/Zn value,and the mechanical strength of the LPSO-containing Mg-Zn-Y-Mn system is gradually improved when increasing LPSO *** the highest volume fraction of LPSO phase,ZW48 alloy presents the highest ultimate tensile strength(UTS)of 427 MPa along the extrusion direction(ED)when compared with those of ZW12 alloy with the UTS of 307 MPa and ZW24 alloy with the UTS of 347 ***,the elongation ratio of ZW48 alloy is maintained to moderate 9.9%,which is also the highest among three studied *** the other hand,texture analysis demonstrates that the basal texture of the a-Mg phase in the ZW48 alloy is significantly weakened by the generation of more LPSO *** the contrary,a high texture intensity of a-Mg phase and obvious mechanical anisotropy can be observed for the ZW12 ***,mechanical anisotropy still exists in the ZW48 alloy containing massive LPSO phases,which is attributed primarily to the zonal distribution of large LPSO along the ED.

关键词： Microstructure Mg-Zn-Y-Mn alloy LPSO phase Texture Mechanical anisotropy Rare earths

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Self-Lubricating PEO Coating on an Al Alloy Produced by Vacuum Impregnation Post-treatment

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Acta Metallurgica Sinica(English Letters) 2015年第8期28卷 965-974页

作者： Ling Hong dong Wang Guang-dong bian Lin-Lin Wang Shu-Gen Hu College of Mechanical Engineering Zhejiang University Zhejiang Wanliyang Transmission Co. Ltd. College of Engineering Zhejiang Normal University

The objective of this research was to develop a novel self-lubricating coating on an AA6061 aluminum *** coatings were prepared by the plasma electrolytic oxidation（PEO） process using 50-, 500-, and 1000-Hz pulsed direct current, respectively. The as-deposited coatings were then post-treated using two different methods, viz., ultrasonic vibration-aided vacuum oil impregnation（UVOI） and oil impregnation under ambient pressure（OIAP）. After posttreatment, an oil-containing, self-lubricating top layer was formed on the coatings. The effects of the coatings＇ surface morphologies and structures on their oil-holding capabilities were discussed. The results revealed that coatings prepared with higher frequency had a greater oil-holding capacity using OIAP post-treatment, while those prepared with lower frequency had a greater oil-containing capability using UVOI post-treatment. These phenomena are related to the morphologies of the coatings produced with various current modes. The tribological properties of the coatings before and after post-treatments were investigated by pin-on-disc sliding wear tests. Due to the formation of a lubricant-containing top layer, the post-treatment coatings had a lower friction coefficient and improved wear resistance compared with the asdeposited coatings. In addition, the coatings after UVOI treatment had better wear performance than those post-treated using the OIAP process. Among all coatings, the coating produced with a 50-Hz pulsed current followed by UVOI posttreatment achieved the lowest friction coefficient（0.03） and best wear resistance when sliding against a Si3N4 ceramic counterface. This study indicates that a novel self-lubricating coating can be prepared by a PEO process combined with vacuum oil impregnation post-treatment.

关键词： Tribological properties Self-lubricating coating Plasma electrolytic oxidation process Oil impregnation Vacuum

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Viscous Shock Wave to an Inflow Problem for Compressible Viscous Gas with Large Density Oscillations

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Acta Mathematicae Applicatae Sinica 2019年第1期35卷 129-157页

作者： dong-fen bian Li-li FAN Lin HE Hui-jiang ZHAO School of Mathematics and Statistics Beijing Institute of Technology School of Mathematics and Computer Science Wuhan Polytechnic University Institute of Applied Mathematics Academy of Mathematics and Systems Science The Chinese Academy of Sciences School of Mathematics and Statistics Wuhan University Computational Science Hubei Key Laboratory Wuhan University

This paper is concerned with the inflow problem for one-dimensional compressible Navier-Stokes equations. For such a problem, Huang, Matsumura, and Shi showed in [4] that there exists viscous shock wave solution to the inflow problem and both the boundary layer solution, the viscous shock wave, and their superposition are time-asymptotically nonlinear stable provided that both the initial perturbation and the boundary velocity are assumed to be sufficiently small. The main purpose of this paper is to show that similar stability results still hold for a class of large initial perturbation which can allow the initial density to have large oscillations. The proofs are given by an elementary energy method and our main idea is to use the smallness of the strength of the viscous shock wave and the boundary velocity to control the possible growth of the solutions induced by the nonlinearity of the compressible Navier-Stokes equations and the inflow boundary *** key point in our analysis is to deduce the desired uniform positive lower and upper bounds on the density.

关键词： compressible Navier-Stokes equations inflow problem viscous shock wave large density oscillations

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Predicting the degradation behavior of magnesium alloys with a diffusion-based theoretical model and in vitro corrosion testing

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Journal of Materials Science & Technology 2019年第7期35卷 1393-1402页

作者： Zhenquan Shen Ming Zhao dong bian Danni Shen Xiaochen Zhou Jianing Liu Yang Liu Hui Guo Yufeng Zheng Department of Materials Science and Engineering College of EngineeringPeking UniversityBeijing 100871China 9955 Buffalo Speedway #4308 HoustonTXUSA Academy for Advanced Interdisciplinary Studies Peking UniversityBeijing 100871China

Magnesium alloys have shown great potential for their use in the medical device field, due to the promising biodegradability. However, it remains a challenge to characterize the degradation behavior of the Mg alloys in a quantitative manner. As such, controlling the degradation rate of the Mg alloys as per our needs is still hard, which greatly limits the practical application of the Mg alloys as a degradable *** paper discussed a numerical model developed based on the diffusion theory, which can capture the experimental degradation behavior of the Mg alloys precisely. The numerical model is then implemented into a finite element scheme, where the model is calibrated with the data from our previous studies on the corrosion of the as-cast Mg-1 Ca and the as-rolled Mg-3 Ge binary alloys. The degradation behavior of a pin implant is predicted using the calibrated model to demonstrate the model’s capability. A standard flow is provided in a practical framework for obtaining the degradation behavior of any biomedical Mg alloys. This methodology was further verified via the comparison with enormous available experimental results. Lastly, the material parameters defined in this model were provided as a new kind of material property.

关键词： Degradation behavior Diffusion model Finite element simulation Magnesium alloy Corrosion Medical device

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Biomimetic Ti-6Al-4V alloy/gelatin methacrylate hybrid scaffold with enhanced osteogenic and angiogenic capabilities for large bone defect restoration

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Bioactive Materials 2021年第10期6卷 3437-3448页

作者： Limin Ma Xiaolan Wang Ye Zhou Xiongfa Ji Shi Cheng dong bian Lei Fan Lei Zhou Chengyun Ning Yu Zhang Department of Orthopedics Guangdong Provincial People’s HospitalGuangdong Academy of Medical SciencesGuangzhouGuangdong510080China Laboratory of Basic Medicine General Hospital of Southern Theatre Command of the PLAGuangzhou510010China School of Materials Science and Engineering South China University of TechnologyGuangzhou510641China

Titanium-based scaffolds are widely used implant materials for bone defect ***,the unmatched biomechanics and poor bioactivities of conventional titanium-based implants usually lead to insufficient bone *** tackle these challenges,it is critical to develop novel titanium-based scaffolds that meet the bioadaptive requirements for load-bearing critical bone ***,inspired by the microstructure and mechanical properties of natural bone tissue,we developed a Ti-6Al-4V alloy(TC4)/gelatin methacrylate(GelMA)hybrid scaffold with dual bionic features(GMPT)for bone defect *** is composed of a hard 3D-printed porous TC4 metal scaffold(PT)backbone,which mimics the microstructure and mechanical properties of natural cancellous bone,and a soft GelMA hydrogel matrix infiltrated into the pores of PT that mimics the microenvironment of the extracellular *** to the unique dual bionic design,the resultant GMPT demonstrates better osteogenic and angiogenic capabilities than PT,as confirmed by the in vitro and rabbit radius bone defect experimental ***,controlling the concentration of GelMA(10%)in GMPT can further improve the osteogenesis and angiogenesis of *** fundamental mechanisms were revealed by RNA-Seq analysis,which showed that the concentration of GelMA significantly influenced the expression of osteogenesis-and angiogenesis-related genes via the Pi3K/Akt/mTOR *** results of this work indicate that our dual bionic implant design represents a promising strategy for the restoration of large bone defects.

关键词： 3D printing porous titanium alloys Gelatin methacrylate Angiogenesis Osteogenesis

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Penile aseptic abscess in the cavernous body at the base of the penis:a case report

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Frontiers of Nursing 2021年第1期8卷 83-89页

作者： Man-Cheng Xia Ke-Qiang Yin Yu-Sheng Wang Jia-Wei Chen Xiao-dong bian Wei-Bing Shuang First Clinical Medical College Shanxi Medical UniversityTaiyuanShanxi 030001China Department of Urology First Hospital of Shanxi Medical UniversityTaiyuanShanxi 030001China

We report a case of aseptic abscess in the cavernous body at the base of the *** our clinical observation,the patient underwent puncture and drainage of the corpus cavernosum abscess,followed by surgical resection of the abscess wall,with the incisions closed layer by layer with primary *** addition,we paid attention to strengthening the postoperative management by using elastic bandages to wrap the penis intermittently to prevent edema;the incision would not be covered with dressings from the third day after the operation,so as to keep the incision site dry in an open *** the period of indwelling of the catheter after the operation,we noticed the care of the external orifice of the urethra to reduce the occurrence of catheter-related ***,the patient was diagnosed with a penile aseptic abscess in the cavernous body at the base of the *** patient recovered well after surgery and was discharged 1 week *** 1.5 years after the operation,the shape of the penis returned to normal,and the erectile function was *** was seen that good nursing concept is of great help for prognosis,which could avoid infection and edema,and is conducive to wound healing.

关键词： penis aseptic abscess puncture and drainage primary suture nursing

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为致用而读:新闻纸在晚清官场的兴起(1861-1890)

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新闻大学 2019年第5期 46-58,118页

作者：卞冬磊南京大学新闻传播学院

本文通过梳理部分'洋务派'官员的日记、奏折和书信,勉力还原1860年代初到1880年代末晚清官员阅读新闻纸的情形。研究发现,1861年总理衙门设立后,新闻纸逐渐参与到中西交涉的多重事务之中。在此期间,除了继续打探西方军事情报以外,晚清... 详细信息

本文通过梳理部分'洋务派'官员的日记、奏折和书信,勉力还原1860年代初到1880年代末晚清官员阅读新闻纸的情形。研究发现,1861年总理衙门设立后,新闻纸逐渐参与到中西交涉的多重事务之中。在此期间,除了继续打探西方军事情报以外,晚清官员在处理贸易、教案、边疆与朝贡国危机等重大事件中,也十分关注新闻纸上的外国动态、国际形势和对中西交涉的评论,并常根据新闻纸报道处理实际事务。本文认为,晚清洋务官员对新闻纸的实用主义心态,是特殊历史脉络的产物。这种阅读方式在甲午以后,让位于报纸的文人论政,为致用而读遂成为历史书写的低音。

关键词：新闻纸阅读官员致用

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中西映照的开始:晚清新闻纸阅读中的“社会比较”

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编辑之友 2019年第4期 98-104页

作者：卞冬磊南京大学新闻传播学院江苏南京210023

中西比较是近代中国思想史的重要现象,不过以此为主题的研究却寥寥无几。文章以郭嵩焘为个案,据其《伦敦和巴黎日记》,借助社会比较理论的相关叙述,深描了近代中国思想史上一个较早出现、但异常丰富的中西比较过程。研究发现,与亲身出... 详细信息

中西比较是近代中国思想史的重要现象,不过以此为主题的研究却寥寥无几。文章以郭嵩焘为个案,据其《伦敦和巴黎日记》,借助社会比较理论的相关叙述,深描了近代中国思想史上一个较早出现、但异常丰富的中西比较过程。研究发现,与亲身出游或与外国人密切交往相比,阅读新闻纸在促成中西比较意识中扮演更为重要的角色——无论是获取他者信息、中西映照,还是回应中西差异。由郭嵩焘的个案延展开来,近代中国的读书人将目光转向西方、以西方为参照对象、进而追求富强的心态,与新闻纸在阅读世界的兴起息息相关。

关键词：中西映照晚清新闻纸社会比较

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超越虚拟:否思传播研究中的“空间”概念

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新闻大学 2023年第7期207卷 71-85,120页

作者：卞冬磊华东师范大学传播学院上海200241

“空间”概念已经被传播研究的抽象性所笼罩,导致了我们无法去接近空间本身。本文追溯了人文社会科学中空间概念的抽象化历史,以及互联网诞生后虚拟空间的兴起,批判了传播研究对实体空间以及虚拟空间之实在性的忽略。文章指出,在当下的... 详细信息

“空间”概念已经被传播研究的抽象性所笼罩,导致了我们无法去接近空间本身。本文追溯了人文社会科学中空间概念的抽象化历史,以及互联网诞生后虚拟空间的兴起,批判了传播研究对实体空间以及虚拟空间之实在性的忽略。文章指出,在当下的传播研究中,应该首先回到实体空间,一方面将“实体空间中的交流”作为重要的问题域,另一方面将“实”视作通往“虚”的路径,从而使虚拟空间的交流具有可分析性。强调实体空间的重要性,不是强化既有的二元论,而是要恢复一种包含着实体和虚拟的“一体化”概念,以覆盖人类交流的完整经验。

关键词：空间虚拟实体传播研究

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遗忘与重建:作为“传播”的“交通”

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新闻大学 2021年第1期 36-47,118-119页

作者：卞冬磊南京大学新闻传播学院江苏南京210046

现代交通技术的兴起,使社会的流动性日益增强,人的交流亦受此影响。但20世纪上半叶兴起的"传播"却遗忘了"交通",失去了对这一重要日常经验提问的能力。鉴于此,本文追溯了"交通"被学科遗忘的历史,发现传播学所"选择"的是技术上具有瞬时... 详细信息

现代交通技术的兴起,使社会的流动性日益增强,人的交流亦受此影响。但20世纪上半叶兴起的"传播"却遗忘了"交通",失去了对这一重要日常经验提问的能力。鉴于此,本文追溯了"交通"被学科遗忘的历史,发现传播学所"选择"的是技术上具有瞬时性、内容上可产生即刻效果的广播等媒介,由此迅速确立了学科的合法性。传播研究的偏向不仅遮蔽了交通之于交流的影响,也忽视了传播的诸多过程性因素,如地理、身体和基础设施等。基于当下移动经验的普遍化与传播学认识论的反思,本文指出,传播研究应以"移动中的交流"为问题,重建传播的交通意涵,走向一个注重物质情境、超越媒介中心主义、以人类交流为核心议题的开放领域。

关键词：移动交通传播

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