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Diffusion behavior at void tip and its contributions to void shrinkage during solid-state bonding

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Journal of Materials Science & Technology 2018年第8期34卷 1449-1454页

作者： c.Zhang M.Q.Li h.Li School of Materials Science and Engineering Northwestern Polytechnical University State Key Laboratory of Solidification Processing Northwestern Polytechnical University Department of Mechanical Engineering University de Lyon

Solid-state diffusion bonding is an advanced joining technique, which has been widely used to join similar or dissimilar materials. Generally, it is easy to observe the diffusion behavior during dissimilar bonding, but for similar bonding the diffusion behavior has yet been observed via experiments. In this study, the diffusion behavior at void tip was firstly observed during similar bonding of stainless steel. Scanning electron microscopy with energy dispersive spectroscopy was used to examine the interface charac- teristic and diffusion behavior. The results showed that a diffusion region was discovered at void tip. Element concentrations of diffusion region were more than those of void region, but less than those of bonded region. This behavior indicated that the diffusion was ongoing at void tip, but the perfect bond has yet formed. The diffusion region was attributed to the interface diffusion from adjacent region to void tip due to the stress gradient along bonding interface. The mass accumulation at void tip transformed the sharp void tip into smooth one at the beginning of void shrinkage, and then resulted in shorter voids.

关键词： Stainless steel Micro-void morphology Solid-state bonding Void tip Element diffusion

Design of a Biomimetic Skin for an Octopus-Inspired Robot - Part I： characterising Octopus Skin

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Journal of Bionic Engineering 2011年第3期8卷 288-296页

作者： Jinping hou Richard h. c. Bonser George Jeronimidis centre for Biomimetics School of Construction Management and Engineering University of Reading Reading RG6 6AY UK

Octopus skin samples were tested under quasi-static and scissor cutting conditions to measure the in-plane material prop- erties and fracture toughness. Samples from all eight arms of one octopus were tested statically to investigate how properties vary from arm to arm. Another nine octopus skins were measured to study the influence of body mass on skin properties. In- fluence of specimen location on skin mechanical properties was also studied. Material properties of skin, i.e. the Young＇s modulus, ultimate stress, failure strain and fracture toughness have been plotted against the position of skin along the length of arm or body. Statistical studies were carried out to help analyzing experimental data obtained. Results of this work will be used as guidelines for the design and development of artificial skins for an octopus-inspired robot.

关键词： octopus skin uniaxial tension scissor cutting Young's modulus failure strain fracture toughness

Investigation of the Influence of Free convection on the heat Transfer of cylinders with Different Aspect Ratios

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Journal of Thermal Science 2001年第1期10卷 58-63页

作者： c.henselowsky h.c.Kuhlmann 等 ZARMUniversityofBremen AmFallturmD－28359BremenGermany ZARMUniversityofBremen AmFallturmD－28359Brem

The heat transfer from an electrically heated cylinder (wire) of finite length to the surrounding fluid can be divided into heat radiation, conduction and convection. A technical application of these cylinders with typical dimensions of 1-2 mm length and a few micrometers diameter is the *** systematic study should clarify the influence of the convection to three dimensional heat transfer of cylinders. For this aim it is planned to investigate Reynolds numbers below Re = 1 (creeping flow). For this reason measurements should be done under 1g in the earth laboratory and also under microgravity (μg) conditions. comparisons of these measurements under otherwise same conditions allows to distinguish between the pure convection heat transfer and the contributions due to conduction and other effects. For measarements under μg the Drop Tower Bremen can be used as research facility. Due to the fast response of convection to changes in the gravity conditions the Drop Tower is an ideal and cost efficient experimental tool. The experimental setup is build to operate at velocity range of 0-l m/s which includes the whole range of convection from pure free convection at 0 m/s over mixed convection up to pure forced convection at velocities above about 0.15 m/s. This velocity region corresponds to a range of the Reynolds number of Re = 0 - 0.18 for a cylinder of 5 μ m diameter at Tf= 140℃ in air at an ambient temperature of about 21℃.

关键词： thermal anemometry hot-wire microgravity free convection hat transfer.

Quantum Well Infrared Photodetectors:the Basic Design and New Research Directions

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Journal of Semiconductors 2001年第5期22卷 529-537页

作者： h.c.Liu Institute for Microstructural Sciences National Research council

The basic design principles and parameters of GaAs/AlGaAs quantum well infrared photodetectors (QWIP) are *** new research directions,devices and applications suited for QWIPs are *** include monolithic integration of QWIPs with GaAs based electronic and optoelectronic devices,high frequency and high speed QWIPs and applications,multicolor and multispectral detectors,and p-type QWIPs.

关键词：光电探测器量子束红外探测器

Adult metaplastic hutch diverticulum with robotic-assisted diverticulectomy and reconstruction:A case report

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World Journal of clinical cases 2020年第20期8卷 4895-4901页

作者： che h Yang Yi S Lin Yen c Ou Wei c Weng Li h huang chin h Lu chao Y hsu Min c Tung Department of Surgery Division of UrologyTungs’Taichung MetroHarbor HospitalTaichung City 435403Taiwan

BAcKGROUND hutch diverticulum arises from the compromised muscular development at the ureteral *** is a congenital disease and extremely rare in adult,only accounting for about 3%occurrence *** can be either symptomatic or asymptomatic,and relies on image tools for diagnosis and preoperative *** for surgery are dependent on the complications from the *** is about 10%among those with hutch diverticulum,and it still has chances turning into malignancy,especially urothelial cell *** SUMMARY A 27-year-old man was presented with frequently recurrent urinary tract infection for one year,and had suffered from intermittent right flank pain for 3 *** past medical histories were recorded *** obvious abnormalities on laboratory data and urine examination were *** ultrasound,right hydronephrosis was seen and an anatomical abnormality was observed on intravenous *** computed tomography urogram showed one diverticulum seated at superolateral side of right ureteral *** was done and biopsy results showed focal *** discussing with him,roboticassisted diverticulectomy with reconstruction was *** hydronephrosis was greatly improved after *** has completed his 1.5-year follow-ups,and no malignancies were seen from urine cytology and image of intravenous *** Robotic-assisted diverticulectomy and reconstruction to hutch diverticulum is a safe and efficient operation,providing several advantages over open and laparoscopic ones.

关键词： Diverticulum complications Urinary bladder abnormalities Diverticulum surgery Robotic surgical procedures methods Treatment outcome case report

Eight-year follow-up of locally advanced lymphoepithelioma-like carcinoma at upper urinary tract: A case report

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World Journal of clinical cases 2020年第19期8卷 4505-4511页

作者： che h Yang Wei c Weng Yi S Lin Li h huang chin h Lu chao Y hsu Yen c Ou Min c Tung Department of Surgery Division of UrologyTungs'Taichung MetroHarbor HospitalTaichung City 435403Taiwan

BAcKGROUND Urinary tract lymphoepithelioma-like carcinoma is rarely *** it is termed after lymphoepithelioma at the nasopharynx,it behaves more like high grade urothelial carcinoma by immunohistochemical *** published literatures focused on its rarity but few discussed results of long-term *** no available guidelines are applicable,we postulated that principles should be similar to that of urothelial carcinoma at urinary *** of now,this work features the longest follow-up of this cancer at the upper urinary *** SUMMARY A 63-year-old female had a chief complaint of intermittent left flank pain for 2 mo,along with accompanying symptoms including vomiting and body weight loss,about 7 kg over 2 *** data showed normocytic anemia,mildly poor renal function,and *** analysis showed mild *** tomography showed a 4.2-cm-width irregular mass over left renal pelvic and enlarged lymph node at the left renal ***-body bone scan was negative of active bone *** from ureteroscopy showed urothelial *** from laparoscopic nephroureterectomy with bladder cuff resection showed lymphoepithelioma-like carcinoma with muscular invasion(pT3).She took adjuvant chemotherapies of 2 cycles and full courses of radiation *** recurrence was observed with designed investigative *** Locally advanced urinary tract lymphoepithelioma-like carcinoma could benefit from nephroureterectomy and bladder cuff excision in terms of recurrence-free survival.

关键词： Urologic neoplasms pathology Kidney pelvis Tomography X-ray computed carcinoma mortality Kidney neoplasms mortality case report

Microstructure change in Fe-based metallic glass and nanocrystalline alloy induced by liquid nitrogen treatment

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Journal of Materials Science & Technology 2021年第10期69卷 1-6页

作者： M.c.Ri D.W.Ding Y.h.Sun W.h.Wang Institute of Physics Chinese Academy of SciencesBeijing100190China Songshan Lake Materials Laboratory Dongguan523808China

The effects of acyclic liquid nitrogen(LN)treatment in a temperature range of-196℃to 50℃on the thermal and magnetic stability of Fe78Si9B13 and Fe73.5Si13.5B9Nb3cu1 glassy ribbons have been *** intrinsic heterogeneities of the metallic glasses can be activated through cryogenic thermal cycling,making irreversible structural changes after the treatment and inducing rejuvenation to the *** microstructural changes of both Fe-based metallic glass(MG)and nanocrystalline alloy induced by LN treatment were *** experimental results show that the LN treatment could effectively rejuvenate the Fe-Si-B MGs and change their thermomechanical and magnetic *** on the partially-crystallinity and well-known magnetic constants,the increase of the energy at the order of 10m J/g and magnetic domain wall movement and rotation at the order of 5-6μm and 0.5°-0.8°are found for FINEMET-type amorphous alloy after LN *** is also found that LN treatment can contribute a little stored energy to the magnetic domain wall movement and magnetic domain rotation.

关键词： Metallic glasses cryogenic thermal treatment Soft magnetic materials Rejuvenation Stored energy Domain wall

Snap-through of an elastica under bilateral displacement control at a material point

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Acta Mechanica Sinica 2020年第3期36卷 727-734页

作者： Q.Wang h.L.Zou Z.c.Deng Department of Engineering Mechanics Northwestern Polytechnical UniversityXi'an 710072China

Snap-through phenomenon widely occurs for elastic systems,where the systems lose stability at critical *** snapthrough of an elastica under bilateral displacement control at a material point is studied,by regarding the whole elastica as two components,i.e.,pinned-clamped ***,stiffness-curvature curves of two pinned-clamped elasticas are firstly efficiently located based on the second-order mode,which are used to determine the shapes of two *** transformations are used to assemble two components together to form the whole elastica,which reveals four kinds of *** advantage of this way compared with other methods such as the shooting method is that multiple coexisting solutions can be located accurately.O n the load-deflection curves,four branches correspond to four kinds of shapes and first two branches are symmetrical to the last two branches relative to the original *** the bilateral displacement control,the critical points can only appear at saddle-node bifurcations,which is different to that for the unilateral displacement ***,one critical point is found on the first branch and two critical points are found on the secondary *** addition,the snap-through among different branches can be well explained with these critical points.

关键词： Elastica Snap-through critical points Buckling Displacement control

Regulation of thermoelastic properties of concave-packaged DNA adsorption films and its relevant microcantilever detection signals

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Acta Mechanica Sinica 2021年第4期37卷 705-711,I0004页

作者： c.X.Wu N.h.Zhang c.Y.Zhang J.Z.Wu School of Mechanics and Engineering Science Shanghai UniversityShanghai 200444China Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai Institute of Applied Mathematics and MechanicsShanghai 200072China

The packing patterns have close correlation with the thermoelastic properties of DNA adsorption films and the relevant detection signals of *** this paper,we investigate the influence of packing patterns on the thermoelastic properties of DNA adsorption films,the detection signals of microcantilevers and their temperature ***,the Parsegian's empirical potential based on a mesoscopic liquid crystal theory is employed to describe the interaction energy among coarse-grained DNA cylinders;then,the thought experiment method and the force balance method of nonlinear elastic network nodes are combined to characterize the elastic modulus,prestress and thermal expansion coefficient of DNA adsorption films;finally,based on an effective macroscopic continuum model for DNA microbeam deformation,we study the microcantilever resonance frequency shifts caused by DNA adsorptions and the temperature effect on the microcantilever static deflections,*** show that,compared with the convex-packaged,the re-entrant honeycomb packing pattern endows DNA adsorption films with a larger adjustable range of the elastic modulus and prestress,so as to make DNA-microcantilevers having an enhanced dynamic detection signal whereas a weaker response to temperature *** results are expected to provide a new option for the regulation design of DNA composite materials and microbeam sensors.

关键词： DNA-microbeam Packaging pattern Elastic property Thermal expansion coefficient Detection signal