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Acta Metallurgica Sinica(English Letters) 2014年第5期27卷 901-908页

作者： Z.Y.Liu B.L.Xiao W.g.Wang Z.Y.ma School of materials Science and Engineering Dalian University of Technology Shenyang National Laboratory for materials Science Institute of Metal ResearchChinese Academy of Sciences School of Mechanical Engineering Liaoning Shihua University

Carbon nanotube-reinforced 2009Al （CNT/2009Al） composites with randomly oriented CNTs and aligned CNTs were fabricated by friction stir processing （FSP） and FSP-rolling, respectively. The CNT/2009A1 composites with aligned CNTs showed much better tensile properties at room temperature and elevated temperature compared with those with the randomly oriented CNTs, which is mainly attributed to larger equivalent aspect ratio of the CNTs and avoidance of preferential fracture problems. However, much finer grain size was not beneficial to obtaining high strength above 473 K. The aligned CNTs resulted in tensile anisotropy, with the best tensile properties being achieved along the direction of CNT aligning. As the off-axis angle increased, the tensile properties were reduced due to the weakening of the load transfer ability. Furthermore, aligned CNTs resulted in much lower coefficient of thermal expansion compared with randomly oriented CNTs.

关键词： Carbon nanotubes Metal matrix composites Mechanical properties Coefficient of thermalexpansion Friction stir processing

Numerical study of convective heat transfer of a supersonic combustor with varied inlet flow conditions

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Acta Mechanica Sinica 2019年第5期35卷 943-953页

作者： W.H.Fan F.Q.Zhong S.g.ma X.Y.Zhang State Key Laboratory of High Temperature gas Dynamics Institute of MechanicsChinese Academy of SciencesBeijing 100190 China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China

Characteristics of convective heat transfer of a supersonic model combustor with variable inlet flow conditions were studied by numerical simulation in this *** three-dimensional flow and wall heat flux at different air inlet mach numbers of 2.2,2.8 and 3.2 were studied numerically with Reynolds-averaged Navier-Stokes equations with a shear-stress transport(SST)k-ωturbulence model and a three-step reaction ***,ethylene was chosen as the fuel,and the fixed fuel-to-air equivalence ratio is 0.8 in all cases in this *** results of the simulations indicate that wall heat flux distribution of the combustor is very non-uniform with several peaks of wall heat flux at varied *** the low inlet mach number of 2.2,a shock train structure is formed in the isolator,and three peaks of wall heat flux are located respectively on the backward face of the cavity,on the side wall near the fuel injection and on the bottom wall near the injection holes,and a maximum wall heat flux reaches 5.4 MW/*** the medium inlet mach number of 2.8,there exists a much shorter shock structure with three peaks of wall heat flux similar to that of mach number ***,as the inlet mach number increased to 3.2,there is no shock structure upstream of fuel injections,and the combustor flow is in a supersonic mode with different locations and values of wall heat flux *** statistical results of wall heat loading show that the change of total wall heat is not monotonic with the increase of inlet mach number,and the maximum appears in the case of mach number being ***,for all the cases,the bottom wall takes up more than 50%of the total heat loading.

关键词： Wall heat flux Numerical simulation Ethylene Supersonic combustor

Evaluation on the anisotropic brittleness index of shale rock using geophysical logging

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Petroleum 2023年第4期9卷 545-557页

作者： Junchuan gui Jianchun guo Yu Sang Yaxi Chen Tianshou ma P.g.Ranjith Research Institute of Shale gas PetroChina Southwest Oil and Gasfield CompanyChengdu610051China State Key Laboratory of Oil and gas Reservoir geology and Exploitation Southwest Petroleum UniversityChengdu610500China Shunan gas Mine PetroChina Southwest Oil and Gas Field CompanyLuzhou646000China Downhole Service Company CNPC Chuanqing Drilling Engineering Company LimitedChengdu610501China Deep Earth Energy Laboratory Department of Civil EngineeringMonash UniversityMelbourne3800Australia

The brittleness index plays a significant role in the hydraulic fracturing design and wellbore stability analysis of shale *** brittleness indices have been proposed to characterize the brittleness of shale rocks,but almost all of them ignored the anisotropy of the brittleness ***,uniaxial compression testing integrated with geophysical logging was used to provide insights into the anisotropy of the brittleness index for Longmaxi shale,the presented method was utilized to assess brittleness index of Longmaxi shale formation for the interval of 3155e3175 m in CW-1 *** results indicated that the brittleness index of Longmaxi shale showed a distinct anisotropy,and it achieved the minimum value at β=45°-60°.As the bedding angle increased,the observed brittleness index(BI_(2_β))decreased firstly and increased then,it achieved the lowest value at β=40°-60°,and it is consistent with the uniaxial compression testing *** to the isotropic brittleness index(β=0°),the deviation of the anisotropic brittleness index ranged from 10%to 66.7%,in other words,the anisotropy of brittleness index cannot be ignored for Longmaxi *** matter content is one of the main intrinsic causes of shale anisotropy,and the anisotropy degree of the brittleness index generally increases with the increase in organic matter *** present work is valuable for the assessment of anisotropic brittleness for hydraulic fracturing design and wellbore stability analysis.

关键词： Shale rock Brittleness Brittleness index Anisotropy Transverse isotropy geophysical logging

Developmental quantitative genetic analysis of body weights and morphological traits in the turbot, Scophthalmus maximus

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Acta Oceanologica Sinica 2015年第2期34卷 55-62页

作者： WANg Xin'an ma Aijun ma Deyou Yellow Sea Fisheries Research Institute Chinese Academy of Fisheries Sciences/Key Laboratory of Sustainable Development of Marine Fisheries Ministry of Agriculture/Qingdao Key Laboratory for Marine Fish Breeding and Biotechnology

In order to elucidate the genetic mechanism of growth traits in turbot during ontogeny, developmental genetic analysis of the body weights, total lengths, standard lengths and body heights of turbots was conducted by mixed genetic models with additive-dominance effects, based on complete diallel crosses with four different strains of Scophthalmus maximus from Denmark, Norway, Britain, and France. Unconditional genetic analysis revealed that the unconditional additive effects for the four traits were more significant than unconditional dominance effects, meanwhile, the alternative expressions were also observed between the additive and dominant effects for body weights, total lengths and standard lengths. Conditional analysis showed that the developmental periods with active gene expression for body weights, total lengths, standard lengths and body heights were 15–18, 15 and 21–24, 15 and 24, and 21 and 27 months of age, respectively. The proportions of unconditional/conditional variances indicated that the narrow-sense heritabilities of body weights, total lengths and standard lengths were all increased systematically. The accumulative effects of genes controlling the four quantitative traits were mainly additive effects, suggesting that the selection is more efficient for the genetic improvement of turbots. The conditional genetic procedure is a useful tool to understand the expression of genes controlling developmental quantitative traits at a specific developmental period（t-1→t） during ontogeny. It is also important to determine the appropriate developmental period（t-1→t） for trait measurement in developmental quantitative genetic analysis in fish.

关键词： Turbot(Scophthalmus maximus L.) growth developmental genetics genetic effect

Development of acoustic liner in aero engine: A review

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Science China(Technological Sciences) 2020年第12期63卷 2491-2504页

作者： ma XuQiang SU ZhengTao Aviation Key Laboratory of Science and Technology on materials and Application Research for Vibration and Noise Reduction AECC Beijing Institute of Aeronautical MaterialsBeijing 100095China

Noise reduction for aircraft engine has attracted great concern due to the strict noise control regulation nowadays. Conventional perforated sheet-over-honeycomb acoustic liners have been widely used to attenuate turbofan engine noise. To dampen the broadband noise and resist the harsh service conditions with high temperature and pressure in modern turbofan engine,new acoustic liner concepts are proposed and evaluated in the latest decade. In this review,available studies regarding the recent development of liners are gathered. The paper starts with the introduction of acoustic absorption mechanism of local-reacting and extended-reacting liners. The progress of novel passive liners(e.g.,mesh-cap liner,variable-depth liner,metal foam liner,hybrid liner,etc.) is summarized. Furthermore,adaptive liners with tunable geometry dimension or bias flow are illustrated in *** is also mentioned as a hot candidate in the next generation of acoustic liners. Finally,this review identifies benefits and some technical challenges with the goal of unveiling the potential of novel acoustic liner technologies in aero engine.

关键词： aero engine noise acoustic liner Helmholtz resonators composites

Characteristics and mechanisms of the annual asymmetry of thermospheric mass density

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Science China Earth Sciences 2015年第4期58卷 540-550页

作者： ma RuiPing XU JiYao WANg WenBin CHEN guangMing YUAN Wei LEI JiuHou Alan g BURNS JIANg guoYing State Key Laboratory of Space Weather Center for Space Sciences and Applied ResearchChinese Academy of Sciences High Altitude Observatory National Center for Atmospheric Research CAS Key Laboratory of geospace Environment University of Science and Technology of China

In this paper, globally-averaged, thermospheric total mass density, derived from the orbits of -5000 objects at 250, 400, and 550 km that were tracked from 1967 to 2006, has been used to quantitatively study the annual asymmetry of thermospheric mass density and its mechanism（s）. The results show that thermospheric mass density had a significant annual asymmetry, which changed from year to year. The annual asymmetry at the three altitudes varied synchronously and its absolute value increased with altitudes. The results suggest that there is an annual asymmetry in solar EUV radiation that is caused by the difference in the Sun-Earth distance between the two solstices and the random variation of solar activity within a year. This change in radiation results in an annual change in the thermospheric temperature and thus the scale height of the neutral gas, and is the main cause of the annual asymmetry of thermospheric mass density. The annual asymmetry of mass density increases with altitude because of the accumulating effect of the changes in neutral temperature and scale height in the vertical direction.

关键词： annual asymmetry of thermospheric mass density solar EUV radiation Sun-Earth distance

Reduced nonlocal integrable mKdV equations of type(-λ, λ) and their exact soliton solutions

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Communications in Theoretical Physics 2022年第6期74卷 15-20页

作者： Wen-Xiu ma Department of mathematics Zhejiang Normal UniversityJinhua 321004China Department of mathematics King Abdulaziz UniversityJeddah 21589Saudi Arabia Department of mathematics and Statistics University of South FloridaTampaFL 33620-5700United States of America

We conduct two group reductions of the Ablowitz-Kaup-Newell-Segur matrix spectral problems to present a class of novel reduced nonlocal reverse-spacetime integrable modified Korteweg-de Vries equations. One reduction is local, replacing the spectral parameter with its negative and the other is nonlocal, replacing the spectral parameter with itself. Then by taking advantage of distribution of eigenvalues, we generate soliton solutions from the reflectionless Riemann-Hilbert problems, where eigenvalues could equal adjoint eigenvalues.

关键词： nonlocal integrable equation soliton solution Riemann-Hilbert problem

Achieving superior performance in powder-metallurgy near-βtitanium alloy by combining hot rolling and rapid heat treatment followed by aging

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Journal of materials Science & Technology 2024年第4期171卷 24-36页

作者： Fucheng Qiu Tuo Cheng Yuchao Song Orest M.Ivasishin Dmytro g.Savvakin guangyu ma Huiyan Xu College of materials Science and Engineering Jilin UniversityChangchun 130025China International Center of Future Science Jilin UniversityChangchun 130025China g.V.Kurdyumov Institute for Metal Physics KyivUkraine College of Biological and Agricultural Jilin UniversityChangchun 130025China

Heat treatment plays an important role in tailoring the mechanical properties of powder-metallurgy(PM)titanium ***,only limited work about the rapid heat treatment(RHT)of PM titanium alloys has been *** this work,RHT was applied to PM Ti-5Al-5Mo-5V-1Cr-1Fe alloy after hot rolling to study the evolution of its mechanical properties and the influence of residual pores on its *** hot rolling and annealing,a fine and uniformα+βstructure with few residual pores is *** RHT,the primaryαdissolves gradually and completes in theβregion,and theβgrains then grow,resulting in the continuous decrease in elongation after ***,the tensile strength first increases and then decreases with increasing RHT temperature,owing to the increase in volume fraction of secondaryαinα+βregion and theβgrain growth inβ*** contrast to the RHT of cast-and-wrought titanium,the negative influence of residual pores lowers the RHT temperature for obtaining the highest tensile strength to a temperature below theβ-transus *** the negative influence of the residual pores,retained primaryαand fineβgrains with fine secondaryαinside contribute to achieving a good strength/ductility balance(1570 MPa and 6.1%,respectively).Addi-tionally,although at higher cycles to failure,the negative influence of residual pores increases as it affects the crack initiation zone at the subsurface,the good resistance of secondaryαto fatigue crack propaga-tion still enhances the fatigue strength considerably(about 300 MPa).This work suggests a cost-effective strategy to produce titanium alloys with high performance.

关键词： Rapid heat treatment Powder metallurgy Mechanical properties Near-βtitanium Residual pores

Improvement of sludge dewaterability with modified cinder via affecting EPS

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Frontiers of Environmental Science & Engineering 2017年第6期11卷 179-192页

作者： Weichao ma Lei Zhao Huiling Liu Qianliang Liu Jun ma State Key Laboratory of Urban Water Resource and Environment Harbin Institute of Technology Harbin 150090 China School of Architectural Engineering Heilongiiang University Harbin 150080 China Key Laboratory of Structures Dynamic Behavior and Control of the Ministry of Education Harbin Institute of Technology Harbin 150090 China Key Laboratory of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology Harbin Institute of Technology Harbin 150090 China

The relationship between the improvement of sludge dewaterability and variation of organic matters has been studied in the process of sludge pre-conditioning with modified cinder, especially for extracellular polymeric substances （EPS） in the sludge. During the conditioning process, the decreases of total organic carbon （TOC） and soluble chemical oxygen demand （SCOD） were obviously in the supernatant especially for the acid modified cinder （ACMC）, which could be attributed to the processes of adsorption and sweeping. The reduction of polysaccharide and protein in supernatant indicated that ACMC might adsorb EPS so that the tightly bound EPS （TB-EPS） decreased in sludge. In the case of ACMC addition with 24 g·L^-1, SRF of the sludge decreased from 7.85 × 10^12 m·kg^-1 to 2.06× 10^12 m·kg^-1, and the filter cake moisture decreased from 85% to 60%. The reconstruction of ＂floc mass＂ was confirmed as the main sludge conditioning mechanism. ACMC promoted the dewatering performance through the charge neutralization and adsorption bridging with the negative EPS, and provided firm and dense structure for sludge floc as skeleton builder. The passages for water quick transmitting were built to avoid collapsing during the high-pressure process.

关键词： Sludge conditioning Acid or alkali modified cinder TB-EPS Floc mass Floc reconstruction

Iron manganese silicate incorporated bioactive hydrogels for therapy of skin tumor

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Progress in Natural Science:materials International 2022年第2期32卷 171-178页

作者： Wenping ma Hongjian Zhang Hongshi ma Chengtie Wu State Key Laboratory of High Performance Ceramics and Superfine Microstructure Shanghai Institute of Ceramics Chinese Academy of Sciences Center of materials Science and Optoelectronics Engineering University of Chinese Academy of Sciences

There is clinical need to develop a multifunctional composite hydrogel for effectively removing residual tumor tissue and promoting wound healing after surgical resection of skin ***,an iron manganese silicate(FeMn(SiO4))-incorporated bioactive hydrogel for photothermal therapy of skin tumor cells has been successfully designed in the present *** synthesized FeMn(SiO4)(FMS) possessed a hollow sphere structure with rough surface,showing favorable photothermal *** incorporating FMS into the sodium alginate(SA) hydrogel,the prepared composite hydrogel(FMS/SA) exhibited the function of eliminating skin tumor cells in vitro by photothermal therapy(PTT).Moreover,attributed to the released bioactive ions(e.g.,Fe,Mn and Si ions) from FMS,the FMS/SA composite hydrogel presented desirable biocompatibility,which is expected to benefit for skin wound healing of patients after skin tumor ***,the FMS/SA composite hydrogel has potential application in skin tumor therapy and wound healing,providing an effective and feasible strategy for the development of a comprehensive therapy for skin tumor after surgery.

关键词： FeMn(SiO 4 ) Novel photothermal agent Bifunctional hydrogel Tumor therapy