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A comprehensive research on wear resistance of GH4169 superalloy in longitudinal-torsional ultrasonic vibration side milling with tool wear and surface quality

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Chinese Journal of Aeronautics 2024年第4期37卷 556-573页

作者： Baoqi chang Zhaoxi YI Fen ZHANG lian DUAN Ji-an DUAN School of Mechanical and Electrical Engineering Central South UniversityChangsha 410083China State Key Laboratory of High Performance and Complex Manufacturing Central South UniversityChangsha 410083China School of Physics and Electronics Central South UniversityChangsha 410083China

To improve the service and machining performance of the workpiece, the tool wear mechanisms, surface machining quality, and wear resistance in conventional side milling(CSM)and longitudinal-torsional ultrasonic vibration side milling(LTUVSM) of GH4169 superalloy at different cutting lengths are investigated systematically. Tool wear mechanisms are revealed and the correlation between machined surface quality with tool wear is analyzed correspondingly. Tool wear patterns mainly include adhesive wear, diffusion wear, abrasive wear, and chipping *** surface quality is achieved in LTUVSM due to a maximum reduction of flank wear bandwidth and wear rate by 71.9% and 71.5%, respectively, compared to CSM. The friction coefficient,initial wear stage time, and wear volume of dry sliding wear were measured to evaluate the workpiece wear resistance. The maximum reductions in friction coefficient and wear volume in LTUVSM are 18.2% and 15.8% compared to CSM. The regular ultrasonic vibration textures suppress the friction and the growth of contact nodes in the contact area, decreasing the degree of surface wear, which is demonstrated by a 38.8% increase in initial wear stage time compared to *** conclusion, the workpiece in LTUVSM exhibits higher wear resistance because of the improvement of tool wear and the guarantee of surface quality.

关键词： Dry sliding wear Surface quality Tool wear Ultrasonic vibration Wear resistance

Microstructure,wear and friction behavior of CoCrAITaY-xCNTs composite coatings deposited by laser-induction hybrid cladding

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Rare Metals 2024年第4期43卷 1815-1827页

作者： sheng-Feng Zhou Yu Long Yan-liang Yi Cheng Deng lian-Xi Hu Institute of Advanced Wear&Corrosion Resistant and Functional Materials Jinan UniversityGuangzhou510632China Wuhan National Laboratory for Optoelectronics(WNLO) Huazhong University of Science and TechnologyWuhan430074China MOE Key Laboratory of New Processing Technology for Non-Ferrous Metals and Materials Guangxi Key Laboratory of Processing for Non-Ferrous Metals and Featured MaterialsGuangxi UniversityNanning530004China School of Mechatronics Engineering Guangdong Polytechnic Normal UniversityGuangzhou510635China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin150001China

To improve the wear performance of CoCrAlYTa coating,part of the carbon nanotubes(CNTs)chemically reacted with Ta to form reinforcement phase(TaC),while the other CNTs were retained as lubrication ***,the CoCrAlYTa-xCNTs(x=0,1,2,and 4;wt%)composite coatings were prepared by laserinduction hybrid cladding(LIHC),and the microstructure and wear resistance of coatings were systematically *** show that the coatings are mainly composed of TaC,y-(Co,Cr)andβ-(Co,Cr)*** the CNTs content increases from 0 wt%to 4 wt%,the volume fraction of TaC increases from 13.11 vol%to 16.12 vol%.Meanwhile,the nano-hardness ofγ-(Co,Cr)andβ-(Co,Cr)Al are improved from 7.49 and 9.72 to 9.36 and 11.19 GPa,*** a result,the microhardness of coating increases from HV536.25 to HV 738.16,the wear rate decreases from32.4×10^(-3)to 6.1×10^(-3)mg·m^(-1),and the average friction coefficient decreases from 0.55 to *** good wear performance of the coating is attributed to the formation of TaC and the existence of remained CNTs lubricant film.

关键词： Carbon nanotube MCrAlY coating Friction and wear performance Laser-induction hybrid cladding

Determination of ice jam thickness—A new approach

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Journal of Hydrodynamics 2024年第3期36卷 570-581页

作者： Jun Wang lian-sheng Sang Fei-hu Song Tie-jie Cheng Jueyi Sui School of Civil and Water Engineering Hefei University of TechnologyHefei230009China School of Engineering University of Northern British ColumbiaPrince GeorgeCanada

In winter,rivers in cold regions often experience flood disasters resulted from ice jams or ice *** of the variation of ice jam thickness and water level during an ice jammed period are not only a practical need for ice prevention to avoid disaster and plan water resource,but also essential for the development of any mathematical model for predicting the evolution of ice *** far,some equations based on the energy equation have been proposed to describe the relationship between ice jam thickness and water ***,in the derivation of these equations,the local head loss coefficient at the ice jam head and the riverbed slope factor were ***,those reported equations cannot be used to preciously describe the flow energy equation with ice jams and accurately calculate the ice jam thickness and water *** the present study,a more comprehensive theoretical model for hydraulic calculation of ice jam thickness has been derived by considering important and essential factors including riverbed slope and local head loss coefficient at the ice jam ***,based on the data collected from laboratory experiments of ice jam accumulation,the local head loss coefficient at the ice jam head has been calculated,and the empirical equation for calculating the local head loss coefficient has been established by considering flow Froude number and the ratio of ice discharge to flow *** results of this study not only provide a new reference for calculating ice jam thickness and water level,but also present a theoretical basis for accurate CFD simulation of ice jams.

关键词： Energy equation ice jam thickness local head loss coefficient ice jam head riverbed slope

Efficacy of radiofrequency ablation combined with sorafenib for treating liver cancer complicated with portal hypertension and prognostic factors

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World Journal of Gastroenterology 2024年第11期30卷 1533-1544页

作者： Li-Min Yang Hong-Juan Wang Shan-Lin Li Guan-Hua Gan Wen-Wen Deng Yong-sheng chang lian-Feng Zhang Department of Gastroenterology The First Affiliated Hospital of Zhengzhou UniversityZhengzhou 450052Henan ProvinceChina Department of Gastroenterology Zhoukou Central Hospital of Henan ProvinceZhoukou 466000Henan ProvinceChina Department of Gastroenterology The First Affiliated Hospital of Xinxiang Medical CollegeXinxiang 453000Henan ProvinceChina

BACKGROUND Patients with liver cancer complicated by portal hypertension present complex challenges in *** To evaluate the efficacy of radiofrequency ablation in combination with sorafenib for improving liver function and its impact on the prognosis of patients with this *** Data from 100 patients with liver cancer complicated with portal hypertension from May 2014 to March 2019 were analyzed and divided into a study group(n=50)and a control group(n=50)according to the treatment *** research group received radiofrequency ablation(RFA)in combination with sorafenib,and the control group only received *** short-term efficacy of both the research and control groups was *** function and portal hypertension were compared before and after ***-fetoprotein(AFP),glypican-3(GPC-3),and AFP-L3 levels were compared between the two groups prior to and after *** occurrence of adverse reactions in both groups was *** 3-year survival rate was compared between the two *** data were compared between the survival and non-surviving *** identify the independent risk factors for poor prognosis in patients with liver cancer complicated by portal hypertension,multivariate logistic regression analysis was *** When comparing the two groups,the research group's total effective rate(82.00%)was significantly greater than that of the control group(56.00%;P<0.05).Following treatment,alanine aminotransferase and aspartate aminotransferase levels increased,and portal vein pressure decreased in both *** degree of improvement for every index was substantially greater in the research group than in the control group(P<0.05).Following treatment,the AFP,GPC-3,and AFP-L3 levels in both groups decreased,with the research group having significantly lower levels than the control group(P<0.05).The incidence of diarrhea,rash,nausea and vomiting,and fatigue in the research group was significantly great

关键词： Radiofrequency ablation Sorafenib Liver cancer Portal hypertension Efficacy Prognosis analysis

Neurotoxicity of tetramethylammonium ion on larval and juvenile zebrafish:Effects on neurobehaviors and multiple biomarkers

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Journal of Environmental Sciences 2024年第9期143卷 138-147页

作者： Ruixin Zhang Rui Wang Jiajun chang GDaniel sheng Daqiang Yin Key Laboratory of Yangtze River Water Environment Ministry of EducationCollege of Environmental Science and EngineeringTongji UniversityShanghai 200092China Shanghai Institute of Pollution Control and Ecological Security Shanghai 200092China

Tetramethylammonium hydroxide(TMAH)is an important compound that utilized and released by the rapidly expanding semiconductor industry,which could hardly be removed by the conventional wastewater treatment *** a cholinergic agonist,the tetramethylammonium ion(TMA^(+))has been reported to induce toxicity to muscular and respiratory systems of mammals and human,however the toxicity on aquatic biota remains poorly *** investigated the neurotoxic effects of TMA^(+)exposure on zebrafish,based on neurobehavior tests and a series of *** inhibitions on the swimming distance of zebrafish larvae were observed when the exposure level exceeded 50 mg/L,and significant alterations on swimming path angles(straight and deflective movements)occurred even at 10 mg/*** tested neurobehavioral endpoints of zebrafish larvae were significantly positively correlated with reactive oxygen species(ROS)and malondialdehyde(MDA),significantly negatively related with the activities of antioxidant enzymes,but not significantly correlated with the level of acetylcholinesterase(AChE).Such relationship indicates that the observed neurotoxic effects on swimming behavior of zebrafish larvae is mainly driven by oxidative stress,rather than the alterations of *** the highest exposure concentration(200 mg/L),TMA^(+)evoked more severe toxicity on zebrafish juveniles,showing significantly stronger elevation on the MDA activity,and greater inhibitions on the activities of antioxidant enzymes and ACh E,suggesting juveniles were more susceptible to TMA^(+)exposure than larval zebrafish.

关键词： Tetramethylammonium Zebrafish Oxidative stress Acetylcholinesterase Neurobehavior

Molecular Chaperone-Dependent Polymer Translocation through Nanopores: The Effects of Chaperone Concentration and Chaperone-Polymer Interaction

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Chinese Journal of Polymer Science 2024年第1期42卷 125-132,I0011页

作者： chang-sheng Zuo Kang Wang Li-Zhen Sun Ting-Ting Sun Department of Physics Zhejiang University of Science and TechnologyHangzhou 310023China Department of Applied Physics Zhejiang University of TechnologyHangzhou 310014China

The polymer translocation through a nanopore from a donor space(or named cis side) to a receiver space(trans side) in the chaperone-induced crowded environment has attracted increasing attention in recent years due to its significance in biological systems and technological applications. In this work, we mainly focus on the effects of chaperone concentration and chaperone-polymer interaction on the polymer translocation. By assuming the polymer translocation to be a quasi-equilibrium process, the free energy F of the polymer can be estimated by Rosenbluth-Rosenbluth method and then the translocation time τ can be calculated by Fokker-Plank equation based on the obtained free energy landscape. Our calculation results show that the translocation time can be controlled by independently tuning the chaperone concentration and chaperone-polymer interaction at the cis side or the trans side. There exists a critical chaperone-polymer attraction ε~*=-0.2 at which the volume exclusion and interaction effects of the chaperone can balance each other. Additionally, we also find that at large chaperone-polymer attraction, the translocation time is mainly governed by the diffusion coefficient of the polymer.

关键词： Polymer translocation Rosenbluth-Rosenbluth method Fokker-Plank equation Free energy landscapes

Effect of temperature on tribofilm growth and the lubrication of the piston ring-cylinder liner system in two-stroke marine engines

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Friction 2024年第8期12卷 1858-1881页

作者： Xiuyi LYU Jiang HU Yunchuan WANG Jinlu sheng Xuan MA Tongyang LI chang GE Xiqun LU Chongqing Jiaotong University Chongqing 400074China Chongqing Metropolitan College of Science and Technology Chongqing 402167China Harbin Engineering University Harbin 150001China Yantai Zhongke Research Institute of Advanced Materials and Green Chemical Engineering Yantai 264006China State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China

This study is an optimized extension based on the authors’previous research on the tribo-chemical reaction under constant temperature field of two-stroke internal combustion engines(ICEs).It establishes a coupled analysis model that considers the tribo-chemical reactions,dynamic contact,and interface lubrication of the piston ring-cylinder liner(PRCL)system under transient temperature *** this study,for the first time,the prediction of the tribofilm thickness and its influence on the surface micro-topography(the comprehensive roughness)are coupled in the working temperature field of the PRCL system,forming an effective model framework and providing a model basis and analytical basis for subsequent *** study findings reveal that by incorporating temperature and tribofilm into the simulation model,the average friction deviation throughout the stroke decreases from 8.92%to 0.93%when compared to experimental ***,the deviation during the combustion regime reduces from 39.56%to 7.34%.The proposed coupled model provides a valuable tool for the evaluation of lubrication performance of the PRCL system and supports the analysis software forward design in two-stroke ICEs.

关键词： tribofilm piston ring-cylinder liner(PRCL)system temperature comprehensive roughness two-stroke internal combustion engines(ICEs)

Efficacy comparison between Mathieu combined urethral plate incision and onlay island flap urethroplasty for distal hypospadias in patients with urethral plate stenosis

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Asian Journal of Andrology 2024年第4期26卷 433-438页

作者： Tao Zhang An-Bang Zhu chang-Kun Mao Yong-sheng Cao Department of Urology Anhui Provincial Children’s HospitalHefei 230000China The Fifth School of Clinical Medicine Anhui Medical UniversityHefei 230000China.

The aim of the study was to compare the efficacy of Mathieu combined urethral plate incision(Mathieu-IP)versus onlay island flap urethroplasty in patients with distal hypospadias complicated by urethral *** clinical data of 70 patients with distal hypospadias complicated by urethral plate stenosis treated in the Department of Urology,Anhui Provincial Children’s Hospital(Hefei,China),from May 2019 to May 2022,were retrospectively ***-eight patients underwent Mathieu-IP(Mathieu-IP group)and 32 underwent onlay island flap urethroplasty(Onlay group).Follow-ups at 1 month,6 months,and 12 months postoperatively assessed operative time,complications,urethral meatus morphology,and family *** Mathieu-IP group had significantly shorter operative time(mean±standard deviation[s.d.]:81.58±5.18 min)versus the Onlay group(mean±s.d.:110.75±6.05 min;P0.05).Complications were comparable between the *** Mathieu-IP group resulted in a vertical slit-shaped urethral meatus in 89.5%versus 13.8%in the Onlay group(P<0.05).Family satisfaction with general penile appearance and skin shape showed no significant differences,but the Mathieu-IP group had higher satisfaction with meatal position(P<0.05).Mathieu-IP offers simplicity,safety,and shorter operative time compared to *** the techniques effectively treat urethral plate stenosis in distal hypospadias,with reduced postoperative complications compared to tubularized incised plate ***-IP results in a vertical slit-shaped urethral meatus which enhances urinary stream,indicating its potential for broader adoption.

关键词： longitudinal urethral plate incision Mathieu onlay island flap urethroplasty urethral stenosis

Toward high performance microwave absorber by implanting La_(0.8)CoO_(3)nanoparticles on rGO

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Journal of Materials Science & Technology 2024年第7期174卷 176-187页

作者： Li chang Yu-Ze Wang Xin-Ci Zhang Lin Li Hua-Zhang Zhai Mao-sheng Cao Key Laboratory for Photonic and Electronic Bandgap Materials Ministry of EducationSchool of Physics&Electronic EngineeringHarbin Normal UniversityHarbin 150025China School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081China

The advent of“intelligent era”brings our life more convenience,but the electromagnetic radiation sur-rounding us not only greatly threatens human health,also makes information leakage and hidden trouble to national defense ***,it is very urgent to develop novel electromagnetic wave absorption materials with lightweight,strong absorption,tunable absorption frequency and broad band ***,a novel electromagnetic wave absorber is obtained by constructing La_(0.8)CoO_(3)-rGO nanocompos-ite,where La_(0.8)CoO_(3)nanoparticles are anchored on graphene nanosheets by the electrostatic interaction between GO and La_(0.8)CoO_(3).The effect of hybridization ratio of La_(0.8)CoO_(3)and rGO on microwave ab-sorption properties is carefully *** optimal reflection loss of La_(0.8)CoO_(3)-rGO nanocomposite can reach-62.34 dB with the maximum effective bandwidth of 6.08 GHz,presenting 48.78%and 245.45%increment compared to bare La_(0.8)CoO_(3)nanoparticles,*** effective absorption bandwidth covers a broad electromagnetic wave absorption band from Ku band to the C band by tailoring thickness of the absorbers from 2.4 mm to 4.4 *** fascinating electromagnetic wave absorption performance is attributed to the synergy effect of La_(0.8)CoO_(3)and rGO,which integrates magnetic and dielectric loss caused by resonance,conductance,relaxation,and scattering *** result confirms that La_(0.8)CoO_(3)-rGO nanocomposite is potential candidates toward high-efficiency microwave absorbers and provides a valuable pathway for designing high-performance microwave attenuation materials in the future.

关键词： Perovskite La_(0.8)CoO_(3)nanoparticles Graphene Nanocomposite Microwave absorbing Broad band absorption