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Numerical Method Based on Compatible Manifold Element for Thin Plate Bending

Chinese Journal of Mechanical Engineering 2010年第1期23卷 100-109页

作者： zhang zhengrong zhang Xiangwei Lu Wenge Faculty of Materials and Energy Guangdong University of Technology Guangzhou 510006 China Faculty of Electromeehanical Engineering Guangdong University of Technology Guangzhou 510006 China

The typical quadrangular and triangular elements for thin plate bending based on Kirchhoff assumptions are the non- conforming elements with low computational accuracy and limitative application range in fmite element method（FEM）. Some compatible elements can be developed by the means of supplementing correction functions, increasing nodes in element or on the boundaries, expanding nodal degrees of freedom（DOF）, etc, but these elements are inconvenient to apply in practice for the high calculation complexity. In this paper, in order to overcome the defects of thin plate bending finite element, numerical manifold method（NMM） was introduced to solve thin plate bending deformation problem. Rectangular mesh was adopted as mathematical mesh to form f＇mite element cover system, and then 16-cover manifold element was proposed. Numerical manifold formulas were constructed on the basis of minimum potential energy principle, displacement boundary conditions are implemented by penalty function method, and all the element matrixes were derived in details. The 16-cover element has a simple calculation process for employing only the transverse displacement cover DOFs as the basic unknown variables, and has been proved to meet the requirements of completeness and full compatibility. As an application, the presented 16-cover element has been used to analyze bending deformation of square thin plate under different loads and boundary conditions, and the results show that numerical manifold method with compatible element, compared with finite element method, can improve computational accuracy and convergence greatly.

关键词： thin plate bending numerical manifold method compatible element 16-cover manifold element

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COUPLED THERMO MECHANICAL FEM ANALYSIS OF TWIST COMPRESSION DEFORMATION PROCESS

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中国有色金属学会会刊:英文版 1997年第4期7卷 103-107页

作者： Xue Kemin zhang zhengrong Xia Yongjiang Lu Yan Metal Forming Division #435Harbin Institute of TechnologyHarbin 150001

3-D rigid-viscoplastic FEM of compressible materials was applied to analyze the deformation behavior during twist compression forming of axisymmetrical body at high temperatures. When calculating the temperature fields, considering the thermo mechanical coupling effect between temperature and deformation, 2-D FEM and CNG methods were adopted, and the up winding technique was used to avoid the influences of numerical instability on calculated results.

关键词： twist-compression rigid-viscoplastic FEM thermo mechanical coupling

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Phenology of different types of vegetation and their response to climate change in the Qilian Mountains,China

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Journal of Mountain Science 2024年第2期21卷 511-525页

作者： ZHAO Kaixin LI Xuemei zhang zhengrong LIU Xinyu Faculty of Geomatics Lanzhou Jiaotong UniversityLanzhou 730070China National-Local Joint Engineering Research Center of Technologies and Applications for National Geographic State Monitoring Lanzhou 730070China Gansu Provincial Engineering Laboratory for National Geographic State Monitoring Lanzhou 730070China

The Qilian Mountains(QM)possess a delicate vegetation ecosystem,amplifying the evident response of vegetation phenology to climate *** relationship between changes in vegetation growth and climate remains *** this end,we used MODIS NDVI data to extract the phenological parameters of the vegetation including meadow(MDW),grassland(GSD),and alpine vegetation(ALV))in the QM from 2002 to ***,we employed path analysis to reveal the direct and indirect impacts of seasonal climate change on vegetation ***,we decomposed the vegetation phenology in a time series using the trigonometric seasonality,Box-Cox transformation,ARMA errors,and Trend Seasonal components model(TBATS).The findings showed a distinct pattern in the vegetation phenology of the QM,characterized by a progressive shift towards an earlier start of the growing season(SOS),a delayed end of the growing season(EOS),and an extended length of the growing season(LOS).The growth cycle of MDW,GSD,and ALV in the QM species is clearly *** SOS for MDW and GSD occurred earlier,mainly between late April and August,while the SOS for ALVs occurred between mid-May and mid-August,a one-month delay compared to the other *** EOS in MDW and GSD were concentrated between late August and April and early September and early January,*** phenology exhibits distinct responses to seasonal temperature and precipitation *** advancement and delay of SOS were mainly influenced by the direct effect of spring temperatures and precipitation,which affected 19.59%and 22.17%of the study area,*** advancement and delay of EOS were mainly influenced by the direct effect of fall temperatures and precipitation,which affected 30.18%and 21.17%of the area,*** the contrary,the direct effects of temperature and precipitation in summer and winter on vegetation phenology seem less noticeable and were mainly influenced by indirect *** indirec

关键词： Vegetation phenology Time series decomposition Path Analysis Climate change

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Effects of Homogenized Treatment on Microstructure and Mechanical Properties of AlCoCrFeNi_(2.2) Near-Eutectic High-Entropy Alloy

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Acta Metallurgica Sinica(English Letters) 2021年第8期34卷 1079-1086页

作者： Xuan Huang Yong Dong Shaomu Lu Chuanqiang Li zhengrong zhang School of Materials and Energy Guangdong University of TechnologyGuangzhou 510006China

A 4 kg AlCoCrFeNi_(2.2) near-eutectic high-entropy alloy ingot was prepared by vacuum medium frequency induction melting. The effects of homogenized treatment on microstructure and mechanical properties of AlCoCrFeNi_(2.2) were studied. The results showed that all the alloys consisted of the primary FCC phases and eutectic FCC/B2 phases. After homogenized treatment, lots of precipitated phases appeared in the primary phase. The hardness of the as-cast alloy was HV296. The hardness values of samples were decreased and were around HV250 after homogenized treatment. The tensile fracture strength of the as-cast alloy reached 900 MPa, while the elongation was 18%. After homogenized treatment at 900 ℃, the alloy showed the most excellent mechanical properties with the fracture strength 880 MPa and the elongation was 29%, respectively. All the alloys displayed a mixture fracture mechanism, including ductile fracture in primary FCC phases and eutectic FCC phases, and brittle quasi-cleavage fracture in eutectic B2 phases. Through a simple heat treatment method, the strength of the alloy was not reduced but the plasticity was greatly enhanced, which was more conducive to the industrial application prospects.

关键词： High-entropy alloys Eutectic alloys Microstructure Tensile strength Microhardness

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Double-branch fusion network with a parallel attention selection mechanism for camouflaged object detection

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Science China(Information Sciences) 2023年第6期66卷 258-266页

作者： Junjiang XIANG Qing PAN zhengrong zhang Songnian FU Yuwen QIN Advanced Institute of Photonics Technology School of Information EngineeringGuangdong University of Technology Guangdong Provincial Key Laboratory of Photonics Information Technology Guangdong University of Technology Guangxi Key Laboratory of Multimedia Communications and Network Technology School of Computer Electronics and InformationGuangxi University

To meet the challenge of camouflaged object detection (COD),which has a high degree of intrinsic similarity between the object and background,this paper proposes a double-branch fusion network(DBFN)with a parallel attention selection mechanism (PASM).In detail,a schismatic receptive field block(SRF)combined with an attention mechanism for low-level information is performed to learn texture features in one branch,and an integration of the SRF,a hybrid attention mechanism (HAM),and a depth feature polymerization module (DFPM)is employed for high-level information to extract detection features in the other ***,both texture features and detection features are input into the PASM to acquire selective expression ***,the final result is obtained after further selective matrix optimization with atrous spatial pyramid pooling (ASPP)and a residual channel attention block (RCAB)being applied *** results on three public datasets verify that our method outperforms the state-of-the-art methods in terms of four evaluation metrics,i.e.,mean absolute error (MAE),weighted F βmeasure (Fβω),structural measure (Sα),and E-measure (Eφ)

关键词： camouflaged object detection attention mechanism feature extraction feature aggregation texture information fuzzy boundary

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Effects of V Addition on Microstructural Evolution and Mechanical Properties of AlCrFe_(2)Ni_(2) High‑Entropy Alloys

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Acta Metallurgica Sinica(English Letters) 2023年第3期36卷 391-404页

作者： Shougang Duan Qian zhang Wenxuan Li Yong Dong Beibei Jiang Shichao Liu Chuanqiang Li zhengrong zhang School of Materials and Energy Guangdong University of TechnologyGuangzhou 510006China GDUT Analysis and Test Center Guangdong University of TechnologyGuangzhou 510006China School of Tron and Steel Soochow UniversitySuzhou 215021China

The effects of vanadium addition on the microstructural evolution and mechanical properties of AlCrFe_(2)Ni_(2) high-entropy alloy(HEA)were *** results showed that the AlCrFe_(2)Ni_(2)V_(0.2) HEA was composed of FCC phase,disordered BCC phase,and ordered BCC(B2)*** the increase in vanadium content,the formation of FCC phase was inhibited,and a transition from FCC phase to BCC phase *** FCC phase disappeared completely when the value of x exceeds 0.4 in AlCrFe_(2)Ni_(2)V_(x) ***,the amplitude-modulated microstructure morphology transformed from a B2 phase matrix with dispersed BCC nano-phase into an alternating interconnected B2 and BCC *** element has the function of stabilizing BCC phase and B2 phase in AlCrFe_(2)Ni_(2)V_(x) *** hardness of AlCrFe_(2)Ni_(2)V_(x) alloys increased from HV 332.4 to HV 590.7,while the yield strength increased from 765 to 1744.6 MPa with increasing vanadium content,which was mainly due to the decreasing content of FCC phase and the solid solution strengthening of vanadium *** the same time,the compression ratio of the alloys decreased with the disappearance of the FCC *** the alloys,the AlCrFe_(2)Ni_(2)V_(0.2) alloy possessed the most excellent comprehensive mechanical properties with yield strength,fracture strength,and compressive ratio 1231.1,2861.9 MPa,and 44.5%,respectively.

关键词： High-entropy alloys Microstructure Phase transformation Mechanical properties Solid solution strengthening

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Molecular Cloning,Characterization and Expression Profile of Myf5 and Myf6 During Growth and Development in the Seriola lalandi

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Journal of Ocean University of China 2021年第6期20卷 1597-1605页

作者： SHI Bao SUN Ranran LIU Xuezhou zhang zhengrong XU Yongjiang JIANG Yan WANG Bin Key Laboratory of Sustainable Development of Marine Fisheries Ministry of Agriculture and Rural AffairsYellow Sea Fisheries Research InstituteChinese Academy of Fishery SciencesQingdao 266071China Laboratory for Marine Fisheries and Food Production Processes Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao 266237China College of Fisheries and Life Science Dalian Ocean UniversityDalian 116023China

Myogenic Regulatory Factors(MRFs)is involved in the muscle growth and *** this study,the cDNA sequence of yellowtail kingfish MRFs genes were cloned by rapid amplification of cDNA ends(RACE)method;then,the character-istics of these genes and the predicted protein sequences were analyzed by bioinformatics methods,the tissue and embryonic stages differential expression pattern were detected by the quantitative real-time *** results showed that the yellowtail kingfish(YTK)Myf5 cDNA has a full length of 951 bp,encoding 266 amino *** yellowtail kingfish Myf6 cDNA has a full length of 1105bp,encoding 250 amino *** proteins containα-helix,β-strand,and *** Neighbour-joining tree revealed that YTK Myf5 and Myf6 are closely related to Seriola *** yellowtail kingfish Myf5 and Myf6 gene expressed significantly higher in mus-cle than in other tissues(P<0.05).In addition,Myf5 and Myf6 in muscle was significantly expressed in 400g and 500 g fish but not in 50 g,suggesting that myogenic regulatory factors expression had a great relationship with the fish *** results also indicated that Myf5 and Myf6 have different functions during embryonic development,because Myf5 showed highest expression level at the neuroembryo period,but Myf6 had the highest expression level at embryo coverage yolk 70%***5 gene showed highest ex-pression at 30 d of age,suggesting it played key roles in myogenic ***,the Myf6 gene was significantly highly ex-pressed at 60 d,revealing this gene functioned in the later muscle formation period.

关键词： Seriola lalandi myogenic regulatory factors gene cloning expression

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Unraveling the interfacial effect of PdBi bimetallic catalysts on promoting CO_(2)electroreduction to formate

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Nano Research 2023年第8期16卷 10822-10831页

作者： Wenhui Liu Lingtong Ding Minmin Liu Xiao Wang zhengrong zhang Tian-Wen Jiang Shengjuan Huo Wen-Bin Cai International Joint Laboratory of Catalytic Chemistry Department of ChemistryInstitute for Sustainable EnergyCollege of SciencesShanghai UniversityShanghai 200444China Shenzhen Key Laboratory of Nanobiomechanics Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China Paul C.Lauterbur Research Center for Biomedical Imaging Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Collaborative Innovation Center of Chemistry for Energy MaterialsDepartment of ChemistryFudan UniversityShanghai 200438China

Through interface engineering and content control strategy,a PdBi bimetallic interface structure was constructed for the first time to selectively convert CO_(2)to formate with a remarkably high Faraday efficiency(FEformate)of 94%and a partial current density(jformate)of 34 mA·cm^(−2)at−0.8 V *** hydrogen electrode(RHE)in an ***,the PdBi interface electrocatalyst even exhibited a high current density of 180 mA·cm^(−2)with formate selectivity up to 92%in a flow cell and could steadily operate for at least 20 *** in-situ attenuated total reflection surface enhanced infrared absorption spectroscopy(ATR-SEIRAS)confirmed that the PdBi interface could greatly weaken the adsorption of*CO intermediates due to electronic and geometric *** functional theory(DFT)calculations also established that the PdBi interface regulated the CO_(2)-to-formate pathway by reducing the energy barrier toward HCOOH and largely weakening the adsorption of*CO intermediates on the catalyst *** study reveals that the unique PdBi bimetallic interface can provide a novel platform to study the reaction mechanism through combining in-situ ATR-SEIRAS and DFT calculations.

关键词： carbon dioxide reduction reaction bimetallic PdBi interface engineering formate in-situ attenuated total reflection surface enhanced infrared absorption spectroscopy(ATR-SEIRAS)

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NEW EXPRESSIONS OF PERIODIC WAVES AND A NOVEL PHENOMENON IN A COMPRESSIBLE HYPERELASTIC ROD

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Journal of Partial Differential Equations 2007年第1期20卷 80-96页

作者： Liu zhengrong zhang Bengong School of Mathematics Science Center for Nonlinear Science Studies South China University of Technology Guangzhou Guangdong 510640 China

A In this paper, we employ both bifurcation method of dynamical systems and numerical exploration of differential equations to investigate the periodic waves of a general compressible hyperelastic rod equation ut＋3uux-uxxt-γ（2uxuxx＋uuxxx）=0, with parameter γ 〈 0. New expressions including explicit expressions and implicit expressions are obtained. Some previous results are extended. Specially, a new phenomenon is found： when the initial value tends to a certain number, the periodic shock wave suddenly changes into a smooth periodic wave. In dynamical systems, this represents that one of orbits can pass through the singular line. The coherency of numerical simulation and theoretical derivation implies the correctness of our results.

关键词： Hyperelastic rod bifurcation method numerical exploration periodic waves.

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A CMIP6-based assessment of regional climate change in the Chinese Tianshan Mountains

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Journal of Arid Land 2024年第2期16卷 195-219页

作者： LIU Xinyu LI Xuemei zhang zhengrong ZHAO Kaixin LI Lanhai Faculty of Geomatics Lanzhou Jiaotong UniversityLanzhou 730070China National-Local Joint Engineering Research Center of Technologies and Applications for National Geographic State Monitoring Lanzhou 730070China Gansu Provincial Engineering Laboratory for National Geographic State Monitoring Lanzhou 730070China State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011China Research Center for Ecology and Environment of Central Asia Chinese Academy of SciencesUrumqi 830011China

Climate warming profoundly affects hydrological changes,agricultural production,and human *** and semi-arid areas of China are currently displaying a marked trend of warming and *** Chinese Tianshan Mountains(CTM)have a high climate sensitivity,rendering the region particularly vulnerable to the effects of climate *** this study,we used monthly average temperature and monthly precipitation data from the CN05.1 gridded dataset(1961-2014)and 24 global climate models(GCMs)of the Coupled Model Intercomparison Project Phase 6(CMIP6)to assess the applicability of the CMIP6 GCMs in the CTM at the regional *** on this,we conducted a systematic review of the interannual trends,dry-wet transitions(based on the standardized precipitation index(SPI)),and spatial distribution patterns of climate change in the CTM during *** further projected future temperature and precipitation changes over three terms(near-term(2021-2040),mid-term(2041-2060),and long-term(2081-2100))relative to the historical period(1961-2014)under four shared socio-economic pathway(SSP)scenarios(i.e.,SSP1-2.6,SSP2-4.5,SSP3-7.0,and SSP5-8.5).It was found that the CTM had experienced significant warming and wetting from 1961 to 2014,and will also experience warming in the future(2021-2100).Substantial warming in 1997 was captured by both the CN05.1 derived from interpolating meteorological station data and the multi-model ensemble(MME)from the CMIP6 *** MME simulation results indicated an apparent wetting in 2008,which occurred later than the wetting observed from the CN05.1 in *** GCMs generally underestimated spring temperature and overestimated both winter temperature and spring precipitation in the *** and wetting are more rapid in the northern part of the *** the end of the 21st century,all the four SSP scenarios project warmer and wetter conditions in the CTM with multiple dry-wet ***,the rise in precipitation fails to counterbal

关键词： climate change Coupled Model Intercomparison Project Phase 6(CMIP6) global climate models(GCMs) shared socio-economic pathway(SSP)scenarios standardized precipitation index(SPI) Chinese Tianshan Mountains

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