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Characteristics and demographic factors of traditional Chinese medicine constitution types among elderly individuals in China:A national multistage cluster random study Author links open overlay panel
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作者 Jing Xia Minghua Bai +6 位作者 Huirong Song Houqin Li Dayan Zhang Mary Y.Jiang Ran Chen Feiyu He Cheng Ni 《Journal of Traditional Chinese Medical Sciences》 CAS 2024年第3期257-263,共7页
Objective To reveal the distribution characteristics and demographic factors of traditional Chinese medicine(TCM)constitution among elderly individuals in China.Methods Elderly individuals from seven regions in China ... Objective To reveal the distribution characteristics and demographic factors of traditional Chinese medicine(TCM)constitution among elderly individuals in China.Methods Elderly individuals from seven regions in China were selected as samples in this study using a multistage cluster random sampling method.The basic information questionnaire and Constitution in Chinese Medicine Questionnaire(Elderly Edition)were used.Descriptive statistical analysis,chi-squared tests,and binary logistic regression analysis were used.Results The single balanced constitution(BC)accounted for 23.9%.The results of the major TCM constitution types showed that BC(43.2%)accounted for the largest proportion and unbalanced constitutions ranged from 0.9%to 15.7%.East China region(odds ratio[OR]=2.097;95%confidence interval[CI],1.912 to 2.301),married status(OR=1.341;95%CI,1.235 to 1.457),and managers(OR=1.254;95%CI,1.044 to 1.505)were significantly associated with BC.Age>70 years was associated with qi-deficiency constitution and blood stasis constitution(BSC).Female sex was significantly associated with yang-deficiency constitution(OR=1.646;95%CI,1.52 to 1.782).Southwest region was significantly associated with phlegm-dampness constitution(OR=1.809;95%CI,1.569 to 2.086).North China region was significantly associated with inherited special constitution(OR=2.521;95%CI,1.569 to 4.05).South China region(OR=2.741;95%CI,1.997 to 1.3.763),Central China region(OR=8.889;95%CI,6.676 to 11.835),senior middle school education(OR=2.442;95%CI,1.932 to 3.088),and managers(OR=1.804;95%CI,1.21 to 2.69)were significantly associated with BSC.Conclusions This study defined the distribution characteristics and demographic factors of TCM constitution in the elderly population.Adjusting and improving unbalanced constitutions,which are correlated with diseases,can help promote healthy aging through the scientific management of these demographic factors. 展开更多
关键词 constitution in Chinese Medicine Questionnaire(Elderly Edition) Body constitution Multistage cluster random sampling Demographic factors Elderly individuals
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Theoretical investigation on axial cyclic performance of monopile in sands using interface constitutive models
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作者 Pan Zhou Jingpei Li +2 位作者 Kaoshan Dai Stefan Vogt Seyedmohsen Miraei 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第7期2645-2662,共18页
Cyclic loads generated by environmental factors,such as winds,waves,and trains,will likely lead to performance degradation in pile foundations,resulting in issues like permanent displacement accumulation and bearing c... Cyclic loads generated by environmental factors,such as winds,waves,and trains,will likely lead to performance degradation in pile foundations,resulting in issues like permanent displacement accumulation and bearing capacity attenuation.This paper presents a semi-analytical solution for predicting the axial cyclic behavior of piles in sands.The solution relies on two enhanced nonlinear load-transfer models considering stress-strain hysteresis and cyclic degradation in the pile-soil interaction.Model parameters are calibrated through cyclic shear tests of the sand-steel interface and laboratory geotechnical testing of sands.A novel aspect involves the meticulous formulation of the shaft loadtransfer function using an interface constitutive model,which inherently inherits the interface model’s advantages,such as capturing hysteresis,hardening,degradation,and particle breakage.The semi-analytical solution is computed numerically using the matrix displacement method,and the calculated values are validated through model tests performed on non-displacement and displacement piles in sands.The results demonstrate that the predicted values show excellent agreement with the measured values for both the static and cyclic responses of piles in sands.The displacement pile response,including factors such as bearing capacity,mobilized shaft resistance,and convergence rate of permanent settlement,exhibit improvements compared to non-displacement piles attributed to the soil squeezing effect.This methodology presents an innovative analytical framework,allowing for integrating cyclic interface models into the theoretical investigation of pile responses. 展开更多
关键词 PILES Cyclic degradation Load-transfer models Interface constitutive model Semi-analytical solution Model tests
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Prediction of Hot Deformation Behavior of 7Mo Super Austenitic Stainless Steel Based on Back Propagation Neural Network
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作者 WANG Fan WANG Xitao +1 位作者 XU Shiguang HE Jinshan 《材料导报》 EI CAS CSCD 北大核心 2024年第17期165-171,共7页
The hot compression tests of 7Mo super austenitic stainless(SASS)were conducted to obtain flow curves at the temperature of 1000-1200℃and strain rate of 0.001 s^(-1)to 1 s^(-1).To predict the non-linear hot deformati... The hot compression tests of 7Mo super austenitic stainless(SASS)were conducted to obtain flow curves at the temperature of 1000-1200℃and strain rate of 0.001 s^(-1)to 1 s^(-1).To predict the non-linear hot deformation behaviors of the steel,back propagation-artificial neural network(BP-ANN)with 16×8×8 hidden layer neurons was proposed.The predictability of the ANN model is evaluated according to the distribution of mean absolute error(MAE)and relative error.The relative error of 85%data for the BP-ANN model is among±5%while only 42.5%data predicted by the Arrhenius constitutive equation is in this range.Especially,at high strain rate and low temperature,the MAE of the ANN model is 2.49%,which has decreases for 18.78%,compared with conventional Arrhenius constitutive equation. 展开更多
关键词 7Mo super austenitic stainless steel hot deformation behavior flow stress BP-ANN Arrhenius constitutive equation
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Investigation of FRP and SFRC Technologies for Efficient Tunnel Reinforcement Using the Cohesive Zone Model
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作者 Gang Niu Zhaoyang Jin +1 位作者 Wei Zhang Yiqun Huang 《Structural Durability & Health Monitoring》 EI 2024年第2期161-179,共19页
Amid urbanization and the continuous expansion of transportation networks,the necessity for tunnel construction and maintenance has become paramount.Addressing this need requires the investigation of efficient,economi... Amid urbanization and the continuous expansion of transportation networks,the necessity for tunnel construction and maintenance has become paramount.Addressing this need requires the investigation of efficient,economical,and robust tunnel reinforcement techniques.This paper explores fiber reinforced polymer(FRP)and steel fiber reinforced concrete(SFRC)technologies,which have emerged as viable solutions for enhancing tunnel structures.FRP is celebrated for its lightweight and high-strength attributes,effectively augmenting load-bearing capacity and seismic resistance,while SFRC’s notable crack resistance and longevity potentially enhance the performance of tunnel segments.Nonetheless,current research predominantly focuses on experimental analysis,lacking comprehensive theoretical models.To bridge this gap,the cohesive zone model(CZM),which utilizes cohesive elements to characterize the potential fracture surfaces of concrete/SFRC,the rebar-concrete interface,and the FRP-concrete interface,was employed.A modeling approach was subsequently proposed to construct a tunnel segment model reinforced with either SFRC or FRP.Moreover,the corresponding mixed-mode constitutive models,considering interfacial friction,were integrated into the proposed model.Experimental validation and numerical simulations corroborated the accuracy of the proposed model.Additionally,this study examined the reinforcement design of tunnel segments.Through a numerical evaluation,the effectiveness of innovative reinforcement schemes,such as substituting concrete with SFRC and externally bonding FRP sheets,was assessed utilizing a case study from the Fuzhou Metro Shield Tunnel Construction Project. 展开更多
关键词 Tunnel segment FRP SFRC cohesive zone model constitutive model fracture process
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Numerical Analysis of Fiber Reinforced Polymer-Confined Concrete under Cyclic Compression Using Cohesive Zone Models
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作者 Mingxu Zhang Mingliang Wang Wei Zhang 《Structural Durability & Health Monitoring》 EI 2024年第5期599-622,共24页
This paper examines the mechanical behavior offiber reinforced polymer(FRP)-confined concrete under cyclic compression using the 3D cohesive zone model(CZM).A numerical modeling method was developed,employing zero-thick... This paper examines the mechanical behavior offiber reinforced polymer(FRP)-confined concrete under cyclic compression using the 3D cohesive zone model(CZM).A numerical modeling method was developed,employing zero-thickness cohesive elements to represent the stress-displacement relationship of concrete potential fracture surfaces and FRP-concrete interfaces.Additionally,mixed-mode damage plastic constitutive models were pro-posed for the concrete potential fracture surfaces and FRP-concrete interface,considering interfacial friction.Furthermore,an anisotropic plastic constitutive model was developed for the FRP composite jacket.The CZM model proposed in this study was validated using experimental data from plain concrete and large rupture strain(LRS)FRP-confined concrete subjected to cyclic compression.The simulation results demonstrate that the pro-posed model accurately predicts the mechanical response of both concrete and FRP-confined concrete under cyc-lic compression.Lastly,various parametric studies were conducted to investigate the internal failure mechanism of FRP-confined concrete under cyclic loading to analyze the influence of the inner friction plasticity of different components. 展开更多
关键词 Cyclic compression CZM FRP wrapped concrete constitutive model fracture behavior
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Comparative Study on Traditional Chinese and Western Medicine Through the Perspective of Constitution Theory in Huangdi Neijing and Hippocrates Corpus
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作者 曾幸 张春月 +1 位作者 李文骄 邹建华 《World Journal of Integrated Traditional and Western Medicine》 2023年第3期52-59,共8页
This article compares the constitution theory of Huangdi Neijing 《黄帝内经》 and Hippocrates Corpus 《希波克拉底文集》 from three aspects:theory,philosophical ideas,and influence on later generations,to analyze the s... This article compares the constitution theory of Huangdi Neijing 《黄帝内经》 and Hippocrates Corpus 《希波克拉底文集》 from three aspects:theory,philosophical ideas,and influence on later generations,to analyze the similarities and differences between two medical systems representing TCM and Western medicine in their early stages of origin.From the comparison and analysis of two books’ history,specific theories in constitution,philosophical characteristics and values in history,we can have a deeper perspective to compare TCM and Western medicine,and have a clearer idea for the development of integrated traditional Chinese and Western medicine. 展开更多
关键词 HuangdiNeijing HippocratesCorpus constitution theory
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Study on hot deformation behavior of homogenized Mg-8.5Gd-4.5Y-0.8Zn-0.4Zr alloy using a combination of strain-compensated Arrhenius constitutive model and finite element simulation method 被引量:2
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作者 Li Hu Mengwei Lang +4 位作者 Laixin Shi Mingao Li Tao Zhou Chengli Bao Mingbo Yang 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第3期1016-1028,共13页
Isothermal hot compression experiments were conducted on homogenized Mg-8.5Gd-4.5Y-0.8Zn-0.4Zr alloy to investigate hot deformation behavior at the temperature range of 673-773 K and the strain rate range of 0.001-1 s... Isothermal hot compression experiments were conducted on homogenized Mg-8.5Gd-4.5Y-0.8Zn-0.4Zr alloy to investigate hot deformation behavior at the temperature range of 673-773 K and the strain rate range of 0.001-1 s^(-1)by using a Gleeble-1500D thermo mechanical simulator.Metallographic characterization on samples deformed to true strain of 0.70 illustrates the occurrence of flow localization and/or microcrack at deformation conditions of 673 K/0.01 s^(-1),673 K/1 s^(-1)and 698 K/1 s^(-1),indicating that these three deformation conditions should be excluded during hot working of homogenized Mg-8.5Gd-4.5Y-0.8Zn-0.4Zr alloy.Based on the measured true stress-strain data,the strain-compensated Arrhenius constitutive model was constructed and then incorporated into UHARD subroutine of ABAQUS software to study hot deformation process of homogenized Mg-8.5Gd-4.5Y-0.8Zn-0.4Zr alloy.By comparison with measured force-displacement curves,the predicted results can describe well the rheological behavior of homogenized Mg-8.5Gd-4.5Y-0.8Zn-0.4Zr alloy,verifying the validity of finite element simulation of hot compression process with this complicated constitutive model.Numerical results demonstrate that the distribution of values of material parameters(α,n,Q and ln A)within deformed sample is inhomogeneous.This issue is directly correlated to the uneven distribution of equivalent plastic strain due to the friction effect.Moreover,at a given temperature the increase of strain rate would result in the decrease of equivalent plastic strain within the central region of deformed sample,which hinders the occurrence of dynamic recrystallization(DRX). 展开更多
关键词 Mg-RE-Zn alloy Hot deformation Microstructure evolution Constitutive model Finite element simulation
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Dynamic compressive response of porcine muscle measured using a split Hopkinson bar system with a pair of PVDF force transducers 被引量:1
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作者 Yao-ke Wen Liang Xu +2 位作者 Ai-jun Chen Fang-dong Dong Bin Qin 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第10期298-305,共8页
The classic metallic Split Hopkinson Pressure Bar(SHPB)cannot capture the transmitted signal accurately when measuring soft biological tissue,because of the very low wave impedance and strength of this material.So the... The classic metallic Split Hopkinson Pressure Bar(SHPB)cannot capture the transmitted signal accurately when measuring soft biological tissue,because of the very low wave impedance and strength of this material.So the dynamic compressive response of porcine muscle has been investigated by using a modified SHPB.The forces on both ends of the sample measured using Polyvinylidene fluor(PVDF)transducers were applied to calculate the stress in the specimen instead of the strain gauge signal on the transmitted bar.Moreover,a circular cardboard disk pulse shaper was applied for generating a suitable incident pulse to achieve stress equilibrium and constant strain rates in the specimens.Then,the dynamic mechanical properties of porcine muscle parallel and perpendicular to the fiber directions were measured,and the stress equilibrium process during loading was analyzed,as well as the inertia-induced extra stress being corrected.Furthermore,quasi-static tests were conducted at two different strain rates to investigate the strain rate dependence using a universal material testing machine.The results show that the stress-strain curves are sensitive to strain rate in the two different loading directions.The compressive stress perpendicular to the fiber direction is stiffer than that parallel to the fiber direction.In addition,a strain rate-dependent constitutive model was developed based on the mechanical response of the muscle at different strain rates and fitted to the experimental data.The results show that the overall fit is good,and the constitutive model could describe the muscle's dynamic mechanical properties. 展开更多
关键词 PVDF Hopkinson bar Porcine muscle Dynamic mechanical properties Constitutive model
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Processing map and dynamic recrystallization behaviours of 316LN-Mn austenitic stainless steel 被引量:1
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作者 Shaolong Sheng Yanxin Qiao +2 位作者 Ruzong Zhai Mingyue Sun Bin Xu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2023年第12期2386-2396,共11页
The hot deformation behaviours of 316LN-Mn austenitic stainless steel were investigated by uniaxial isothermal compression tests at different temperatures and strain rates.The microstructural evolutions were also stud... The hot deformation behaviours of 316LN-Mn austenitic stainless steel were investigated by uniaxial isothermal compression tests at different temperatures and strain rates.The microstructural evolutions were also studied using electron backscatter diffraction.The flow stress decreases with the increasing temperature and decreasing strain rate.A constitutive equation was established to characterize the relationship among the deformation parameters,and the deformation activation energy was calculated to be 497.92 k J/mol.Processing maps were constructed to describe the appropriate processing window,and the optimum processing parameters were determined at a temperature of 1107-1160℃ and a strain rate of 0.005-0.026 s^(-1).Experimental results showed that the main nucleation mechanism is discontinuous dynamic recrystallization(DDRX),followed by continuous dynamic recrystallization(CDRX).In addition,the formation of twin boundaries facilitated the nucleation of dynamic recrystallization. 展开更多
关键词 austenitic stainless steel processing map dynamic recrystallization constitutive equation
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Finite Element Simulation of Radial Tire Building and Shaping Processes Using an Elasto-Viscoplastic Model 被引量:1
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作者 Yinlong Wang Zhao Li +1 位作者 Ziran Li Yang Wang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第5期1187-1208,共22页
The comprehensive tire building and shaping processes are investigated through the finite element method(FEM)in this article.The mechanical properties of the uncured rubber from different tire components are investiga... The comprehensive tire building and shaping processes are investigated through the finite element method(FEM)in this article.The mechanical properties of the uncured rubber from different tire components are investigated through cyclic loading-unloading experiments under different strain rates.Based on the experiments,an elastoviscoplastic constitutive model is adopted to describe themechanical behaviors of the uncured rubber.The distinct mechanical properties,including the stress level,hysteresis and residual strain,of the uncured rubber can all be well characterized.The whole tire building process(including component winding,rubber bladder inflation,component stitching and carcass band folding-back)and the shaping process are simulated using this constitutive model.The simulated green tire profile is in good agreement with the actual profile obtained through 3D scanning.The deformation and stress of the rubber components and the cord reinforcements during production can be obtained fromthe FE simulation,which is helpful for judging the rationality of the tire construction design.Finally,the influence of the parameter“drum width”is investigated,and the simulated result is found to be consistent with the experimental observations,which verifies the effectiveness of the simulation.The established simulation strategy provides some guiding significance for the improvement of tire design parameters and the elimination of tire production defects. 展开更多
关键词 Uncured rubber constitutive modeling radial tire building process finite element method
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Discussion on depression by thinking of t raditional Chinese medicine 被引量:1
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作者 Yi-Tong Huang Cong-Cong Chang 《Medical Theory and Hypothesis》 2023年第1期1-4,共4页
Depression is a common mental disease characterized by abnormal emotional changes,which belongs to the category of“melancholia syndrome”and Chinese emotion medicine.The main clinical manifestations are mood depressi... Depression is a common mental disease characterized by abnormal emotional changes,which belongs to the category of“melancholia syndrome”and Chinese emotion medicine.The main clinical manifestations are mood depression,loss of interest,hallucinations,self-harm,and even suicide.Etiology and pathogenesis can be divided into“inner depression”and“outer depression”,and is related to the susceptibility of the constitution.The diagnosis can be combined with four diagnoses and new techniques.Traditional Chinese medicine(TCM)treatment methods include TCM,psychotherapy,acupuncture,music therapy and so on.TCM treatment of depression has a long history,strong symptomatic,little side effects.It is forward-looking to explore new ideas of understanding and treating depression syndrome with TCM theory,which is helpful to better“prevention before disease”.TCM therapy will certainly play an important role in the treatment of depression in the future. 展开更多
关键词 DEPRESSION TCM theory “inner depression”and“outer depression” constitution susceptible psychological therapy SYMPTOMATIC
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Effect of Temperature and Phase Constitution on Kinetics of La Diffusion 被引量:7
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作者 阎牧夫 Sun Y +2 位作者 Bell T 刘志儒 夏立芳 《Journal of Rare Earths》 SCIE EI CAS CSCD 2002年第4期329-332,共4页
The diffusion of La in ε-Fe 2~3N(ε)and γ′-Fe 4N (γ′)phases produced by plasma nitriding was studied. It is found that with increasing nitriding time, the ε phase continuously decomposes into γ′ one under... The diffusion of La in ε-Fe 2~3N(ε)and γ′-Fe 4N (γ′)phases produced by plasma nitriding was studied. It is found that with increasing nitriding time, the ε phase continuously decomposes into γ′ one under employed experimental conditions and compared with γ′ phase or ε+γ′ ones, the mono one ε has an impedient effect on depth of La diffusion. The growth of La layer in dual phases and mono one follows an approximate exponential law and a parabolic one, respectively, and this kinetics law does not change with increasing temperature. The effect of increasing temperature in the range of 520 to 560 ℃ on La diffusion depth is less than that of phase constitution change such as the decomposition of ε phase into γ′ one. 展开更多
关键词 rare earths TEMPERATURE phase constitution La diffusion KINETICS
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Anisotropic time-dependent behaviors of shale under direct shearing and associated empirical creep models 被引量:2
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作者 Yachen Xie Michael Z.Hou +1 位作者 Hejuan Liu Cunbao Li 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第4期1262-1279,共18页
Understanding the anisotropic creep behaviors of shale under direct shearing is a challenging issue.In this context,we conducted shear-creep and steady-creep tests on shale with five bedding orientations (i.e.0°,... Understanding the anisotropic creep behaviors of shale under direct shearing is a challenging issue.In this context,we conducted shear-creep and steady-creep tests on shale with five bedding orientations (i.e.0°,30°,45°,60°,and 90°),under multiple levels of direct shearing for the first time.The results show that the anisotropic creep of shale exhibits a significant stress-dependent behavior.Under a low shear stress,the creep compliance of shale increases linearly with the logarithm of time at all bedding orientations,and the increase depends on the bedding orientation and creep time.Under high shear stress conditions,the creep compliance of shale is minimal when the bedding orientation is 0°,and the steady-creep rate of shale increases significantly with increasing bedding orientations of 30°,45°,60°,and 90°.The stress-strain values corresponding to the inception of the accelerated creep stage show an increasing and then decreasing trend with the bedding orientation.A semilogarithmic model that could reflect the stress dependence of the steady-creep rate while considering the hardening and damage process is proposed.The model minimizes the deviation of the calculated steady-state creep rate from the observed value and reveals the behavior of the bedding orientation's influence on the steady-creep rate.The applicability of the five classical empirical creep models is quantitatively evaluated.It shows that the logarithmic model can well explain the experimental creep strain and creep rate,and it can accurately predict long-term shear creep deformation.Based on an improved logarithmic model,the variations in creep parameters with shear stress and bedding orientations are discussed.With abovementioned findings,a mathematical method for constructing an anisotropic shear creep model of shale is proposed,which can characterize the nonlinear dependence of the anisotropic shear creep behavior of shale on the bedding orientation. 展开更多
关键词 Rock anisotropy Direct shear creep Creep compliance Steady-creep rate Empirical model Creep constitutive model
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Flow characteristics and hot workability of a typical low-alloy high-strength steel during multi-pass deformation 被引量:1
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作者 Mingjie Zhao Lihong Jiang +4 位作者 Changmin Li Liang Huang Chaoyuan Sun Jianjun Li Zhenghua Guo 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第2期323-336,共14页
Heavy components of low-alloy high-strength(LAHS) steels are generally formed by multi-pass forging. It is necessary to explore the flow characteristics and hot workability of LAHS steels during the multi-pass forging... Heavy components of low-alloy high-strength(LAHS) steels are generally formed by multi-pass forging. It is necessary to explore the flow characteristics and hot workability of LAHS steels during the multi-pass forging process, which is beneficial to the formulation of actual processing parameters. In the study, the multi-pass hot compression experiments of a typical LAHS steel are carried out at a wide range of deformation temperatures and strain rates. It is found that the work hardening rate of the experimental material depends on deformation parameters and deformation passes, which is ascribed to the impacts of static and dynamic softening behaviors. A new model is established to describe the flow characteristics at various deformation passes. Compared to the classical Arrhenius model and modified Zerilli and Armstrong model, the newly proposed model shows higher prediction accuracy with a confidence level of 0.98565. Furthermore, the connection between power dissipation efficiency(PDE) and deformation parameters is revealed by analyzing the microstructures. The PDE cannot be utilized to reflect the efficiency of energy dissipation for microstructure evolution during the entire deformation process, but only to assess the efficiency of energy dissipation for microstructure evolution in a specific deformation parameter state.As a result, an integrated processing map is proposed to better study the hot workability of the LAHS steel, which considers the effects of instability factor(IF), PDE, and distribution and size of grains. The optimized processing parameters for the multi-pass deformation process are the deformation parameters of 1223–1318 K and 0.01–0.08 s^(-1). Complete dynamic recrystallization occurs within the optimized processing parameters with an average grain size of 18.36–42.3 μm. This study will guide the optimization of the forging process of heavy components. 展开更多
关键词 low-alloy high-strength steel work hardening rate constitutive model hot workability multi-pass deformation
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Pore constitution and tortuosity factor of reactively synthesized porous TiAl intermetallic compound 被引量:3
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作者 Yao JIANG Yue-hui HE Hai-yan GAO 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2021年第3期726-733,共8页
The pore constitution and tortuosity factor of porous TiAl intermetallic were studied on the basis of the variation behavior of pore structure parameters and the discrete particle model. The pore formation mechanism o... The pore constitution and tortuosity factor of porous TiAl intermetallic were studied on the basis of the variation behavior of pore structure parameters and the discrete particle model. The pore formation mechanism of porous TiAl is mainly ascribed to three aspects: the clearance space in green compact, the diffusive pores in the reaction process and the phase transition pores, resulting in the open porosities of 5.6%, 42.9% and 1.3%, respectively. According to the Hagen-Poiseuille equation, the tortuosity factor of porous TiAl is determined in the range of 1.3-2.2. Based on the discrete particle model and the variation rule of the tortuosity factor, the tortuosity factor depends mainly on the parameters of fabrication constant, particle shape factor, clearance distance and powder particle size. The quantitative relationships among them have been established, which can be used as the basis for adjusting the pore structure of porous intermetallics. 展开更多
关键词 pore constitution tortuosity factor TiAl intermetallics porous material reactive synthesis
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Thermo-hydro-mechanical (THM) coupled simulation of the land subsidence due to aquifer thermal energy storage (ATES) system in soft soils 被引量:1
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作者 Yang Wang Fengshou Zhang Fang Liu 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第6期1952-1966,共15页
Aquifer thermal energy storage(ATES)system has received attention for heating or cooling buildings.However,it is well known that land subsidence becomes a major environmental concern for ATES projects.Yet,the effect o... Aquifer thermal energy storage(ATES)system has received attention for heating or cooling buildings.However,it is well known that land subsidence becomes a major environmental concern for ATES projects.Yet,the effect of temperature on land subsidence has received practically no attention in the past.This paper presents a thermo-hydro-mechanical(THM)coupled numerical study on an ATES system in Shanghai,China.Four water wells were installed for seasonal heating and cooling of an agriculture greenhouse.The target aquifer at a depth of 74e104.5 m consisted of alternating layers of sand and silty sand and was covered with clay.Groundwater level,temperature,and land subsidence data from 2015 to 2017 were collected using field monitoring instruments.Constrained by data,we constructed a field scale three-dimensional(3D)model using TOUGH(Transport of Unsaturated Groundwater and Heat)and FLAC3D(Fast Lagrangian Analysis of Continua)equipped with a thermo-elastoplastic constitutive model.The effectiveness of the numerical model was validated by field data.The model was used to reproduce groundwater flow,heat transfer,and mechanical responses in porous media over three years and capture the thermo-and pressure-induced land subsidence.The results show that the maximum thermoinduced land subsidence accounts for about 60%of the total subsidence.The thermo-induced subsidence is slightly greater in winter than that in summer,and more pronounced near the cold well area than the hot well area.This study provides some valuable guidelines for controlling land subsidence caused by ATES systems installed in soft soils. 展开更多
关键词 Aquifer thermal energy storage(ATES) Land subsidence TOUGH-FLAC3D Thermo-elastoplastic constitutive model
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Predicting the electromechanical properties of small caliber projectile impact igniter using PZT dynamic damage constitutive model considering crack propagation
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作者 Rui-zhi Wang Zhi-qiang Wang +5 位作者 En-ling Tang Lei Li Guo-lai Yang Chun Cheng Li-ping He Ya-fei Han 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第10期121-135,共15页
Block piezoelectric ceramics(PZTs)are often used in impact igniters to provide activation energy for electric initiators.Under the action of strong impact stress,PZTs release electric energy accompanied by crack initi... Block piezoelectric ceramics(PZTs)are often used in impact igniters to provide activation energy for electric initiators.Under the action of strong impact stress,PZTs release electric energy accompanied by crack initiation,propagation and crushing.At present,the electrical output performance of PZTs in projectile is usually calculated by quasi-static piezoelectric equation without considering the dynamic effect caused by strong impact and the influence of crack propagation on material properties.So the ignition parameters are always not accurately predicted.To tackle this,a PZT dynamic damage constitutive model considering crack propagation is established based on the dynamic impact test and the crack propagation theory of brittle materials.The model is then embedded into the ABAQUS subroutine and used to simulate the electromechanical response of the impact igniter during the impact of a small caliber projectile on the target.Meanwhile,the experiments of projectile with impact igniter impact on the target are carried out.The comparison between experimental and numerical simulation results show that the established dynamic damage model can effectively predict the dynamic electromechanical response of PZTs in the missile service environment. 展开更多
关键词 Piezoelectric ceramics IMPACT IGNITER Dynamic damage constitutive model Electromechanical response
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Trust Shell Based Constitution Model of Trusted Software 被引量:2
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作者 田俊峰 朱叶 《China Communications》 SCIE CSCD 2011年第4期11-22,共12页
Since the guarantee of trustiness is considered inadequate in traditional software development methods,software developed using these methods lacks effective measures for ensuring its trustiness.Combining agent techni... Since the guarantee of trustiness is considered inadequate in traditional software development methods,software developed using these methods lacks effective measures for ensuring its trustiness.Combining agent technique with the support of trusted computing provided by TPM,a trust-shell-based constitution model of trusted software(TSCMTS)is demonstrated,trust shell ensures the trustiness of software logically.The concept of Trust Engine is proposed,which extends the "chain of trust" of TCG into application,and cooperates with TPM to perform integrity measurement for software entity to ensure the static trustiness;Data Structure called trust view is defined to represent the characteristic of software behavior.For the purpose of improving the accuracy of trustiness constraints,a strategy for determining the weights of characteristic attributes based on information entropy is proposed.Simulation experiments illustrate that the trustiness of software developed by the TSCMTS is improved effectively without performance degradation. 展开更多
关键词 trusted computing trusted software constitution trust shell trust engine trust view software behavior trace
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Hot-deformation kinetics analysis and extrusion parameter optimization of a dilute rare-earth free magnesium alloy
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作者 Qinghang Wang Haowei Zhai +5 位作者 Zhaoyang Jin Junjie He Qin Yang Wenjun Liu Yulong Li Daolun Chen 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第9期3302-3322,共21页
The fundamental research on thermo-mechanical conditions provides an experimental basis for high-performance Mg-Al-Ca-Mn alloys.However, there is a lack of systematical investigation for this series alloys on the hot-... The fundamental research on thermo-mechanical conditions provides an experimental basis for high-performance Mg-Al-Ca-Mn alloys.However, there is a lack of systematical investigation for this series alloys on the hot-deformation kinetics and extrusion parameter optimization. Here, the flow behavior, constitutive model, dynamic recrystallization(DRX) kinetic model and processing map of a dilute rare-earth free Mg-1.3Al-0.4Ca-0.4Mn(AXM100, wt.%) alloy were studied under different hot-compressive conditions. In addition, the extrusion parameter optimization of this alloy was performed based on the hot-processing map. The results showed that the conventional Arrhenius-type strain-related constitutive model only worked well for the flow curves at high temperatures and low strain rates. In comparison, using the machine learning assisted model(support vector regression, SVR) could effectively improve the accuracy between the predicted and experimental values. The DRX kinetic model was established, and a typical necklace-shaped structure preferentially occurred at the original grain boundaries and the second phases. The DRX nucleation weakened the texture intensity, and the further growth caused the more scattered basal texture. The hot-processing maps at different strains were also measured and the optimal hot-processing range could be confirmed at the deformation temperatures of 600~723 K and the strain rates of 0.018~0.563 s^(-1). Based on the optimum hot-processing range, a suitable extrusion parameter was considered as 603 K and 0.1 mm/s and the as-extruded alloy in this parameter exhibited a good strength-ductility synergy(yield strength of ~ 232.1 MPa, ultimate strength of ~ 278.2 MPa and elongation-to-failure of ~ 20.1%). Finally, the strengthening-plasticizing mechanisms and the relationships between the DRXed grain size, yield strength and extrusion parameters were analyzed. 展开更多
关键词 Mg-Al-Ca-Mn alloy Constitutive model Dynamic recrystallization kinetic model Extrusion parameter optimization Strengthening-plasticizing mechanisms
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Potential mechanism of Huatan Qushi decoction on improving phlegm-dampness constitution using microRNA array and RT-qPCR targeting on hsa-miR-1237e3p 被引量:3
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作者 Xiuping Zhang Ji Wang +5 位作者 Baoxing Liu Haiqiang Yao Yu Chen Yuqing Yin Xuejing Yang Lingru Li 《Journal of Traditional Chinese Medical Sciences》 2021年第1期43-51,共9页
Background:Metabolic diseases pose considerable burden on the healthcare system worldwide,indicating the significance of prevention and treatment.In constitution theory of traditional Chinese medicine,phlegm-dampness ... Background:Metabolic diseases pose considerable burden on the healthcare system worldwide,indicating the significance of prevention and treatment.In constitution theory of traditional Chinese medicine,phlegm-dampness constitution(PDC)is the common basis of metabolic diseases.In clinical practice,Huatan Qushi(HTQS)decoction targeting on PDC can effectively improve metabolic indicators.However,its underlying biochemical mechanism still remains unclear.Methods:Eight PDC participants received HTQS decoction for three months.Their blood was collected at baseline and 1 and 3 months after intervention started.Related biomedical indicators were detected.High-throughput sequencing and RT-qPCR were used for validation.Due to the missing data,repeated measures with missing values in mixed models were used.Results:After 3-month treatment,HDL-C level increased(P<.001)and FBG,FINS,and HbA1c all showed decreasing trend at different time points(all P<.05).After miRNA high-throughput sequencing,compared with the baseline,differential miRNAs at 1 and 3 months were screened,and target gene prediction and KEGG pathway enrichment analysis were performed.The results displayed that metabolic disease-related pathways mainly included pathways in cancer,PI3K-Akt signaling pathway,etc.Further,RT-qPCR showed that hsa-miR-1237e3p differed statistically(P=.008).Then we validated the target genes of hsa-miR-1237e3p in the“Pathways in Cancer”pathway including SDF1,AC,CRK,and HGF,also known as upstream target genes of PI3K/AKT pathway.The results showed that two indicators of CRK and HGF were in statistical significance(P=.045 and P=.036,respectively).Conclusion:PDC serves as a common basis for various metabolic diseases.Through adjusting PDC,HTQS decoction can improve biomedical indicators including blood glucose,HbA1c,insulin,and HDL-C.The target pathway is“Pathways in cancer”.Specifically,HTQS decoction acts on targets of CRK and HGF by regulating hsa-miR-1237e3p,and probably exerts effects on their downstream PI3K/AKT pathway. 展开更多
关键词 Chinese herbal formula constitution Metabolic disorders Pathways in cancer
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