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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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Constitution identification model in traditional Chinese medicine based on multiple features
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作者 XU Anying WANG Tianshu +7 位作者 YANG Tao HAN Xiao ZHANG Xiaoyu WANG Ziyan ZHANG Qi LI Xiao SHANG Hongcai HU Kongfa 《Digital Chinese Medicine》 CAS CSCD 2024年第2期108-119,共12页
Objective To construct a precise model for identifying traditional Chinese medicine(TCM)constitutions;thereby offering optimized guidance for clinical diagnosis and treatment plan-ning;and ultimately enhancing medical... Objective To construct a precise model for identifying traditional Chinese medicine(TCM)constitutions;thereby offering optimized guidance for clinical diagnosis and treatment plan-ning;and ultimately enhancing medical efficiency and treatment outcomes.Methods First;TCM full-body inspection data acquisition equipment was employed to col-lect full-body standing images of healthy people;from which the constitutions were labelled and defined in accordance with the Constitution in Chinese Medicine Questionnaire(CCMQ);and a dataset encompassing labelled constitutions was constructed.Second;heat-suppres-sion valve(HSV)color space and improved local binary patterns(LBP)algorithm were lever-aged for the extraction of features such as facial complexion and body shape.In addition;a dual-branch deep network was employed to collect deep features from the full-body standing images.Last;the random forest(RF)algorithm was utilized to learn the extracted multifea-tures;which were subsequently employed to establish a TCM constitution identification mod-el.Accuracy;precision;and F1 score were the three measures selected to assess the perfor-mance of the model.Results It was found that the accuracy;precision;and F1 score of the proposed model based on multifeatures for identifying TCM constitutions were 0.842;0.868;and 0.790;respectively.In comparison with the identification models that encompass a single feature;either a single facial complexion feature;a body shape feature;or deep features;the accuracy of the model that incorporating all the aforementioned features was elevated by 0.105;0.105;and 0.079;the precision increased by 0.164;0.164;and 0.211;and the F1 score rose by 0.071;0.071;and 0.084;respectively.Conclusion The research findings affirmed the viability of the proposed model;which incor-porated multifeatures;including the facial complexion feature;the body shape feature;and the deep feature.In addition;by employing the proposed model;the objectification and intel-ligence of identifying constitutions in TCM practices could be optimized. 展开更多
关键词 Traditional Chinese medicine(TCM) constitution identification Deep feature Facial complexion feature Body shape feature Multiple features
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Twenty Years of the Implementation of the Human Rights Clause in the Constitution:Achievements,Implications,and Research Topics
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作者 HAN Dayuan 《The Journal of Human Rights》 2024年第3期509-520,共12页
On March 14,2004,the Second Session of the 10th National People’s Congress of China adopted the fourth amendment to the Chinese Constitution,the most noticeable highlight of which is the addition of the paragraph“th... On March 14,2004,the Second Session of the 10th National People’s Congress of China adopted the fourth amendment to the Chinese Constitution,the most noticeable highlight of which is the addition of the paragraph“the state respects and protects human rights”as the third clause in Article 33 of Chapter II“Basic Rights and Obligations of Citizens”in the Constitution.The inclusion of the clause of human rights in the Constitution is considered an important milestone in the history of human rights development in the People’s Republic of China.The implementation of the human rights clause not only showcases the values of the Party and the state in respecting and protecting human rights,but also promotes the development of human rights,shapes the culture of human rights,and endows the rule of law with a rich humanistic spirit.Over the past 20 years,the publicity,research and practice of the human rights clause have made the Chi-nese people realize that human rights are not only a“great term”,but also a common value shared by mankind.Amid the once-in-a-century changes of the world,although the development of human rights is facing various challenges,the humanistic spirit contained in the hu-man rights clause has become the internal driving force for building consensus in the whole of society.Reinterpreting the significance and value of the human rights clause can help us conscientiously draw on the experience in the implementation of the clause over the past 20 years and contribute Chinese wisdom and experience to global human rights governance with a more open mind and inclusive attitude. 展开更多
关键词 PERSONS human rights constitution human rights clause
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The Connotations of the Constitutional Clause on Human Rights Protection From the Perspective of Foreign-related Rule of Law
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作者 ZHAI Han 《The Journal of Human Rights》 2024年第3期548-566,共19页
The inclusion of the human rights clause in the Chi-nese Constitution is the core normative manifestation of the constitu-tionalization of human rights,and points to the relationship between international law and the ... The inclusion of the human rights clause in the Chi-nese Constitution is the core normative manifestation of the constitu-tionalization of human rights,and points to the relationship between international law and the Constitution in the sense of positive law.The inclusion of the human rights clauses in the Chinese Constitution itself is an inherent part of the development of China’s socialist constitution,and socialism has already contributed valuable concepts and practices of human rights protection to the modern world in its early stage.The constitutionalization of human rights protection does not necessarily lead to the superiority of international law over the constitutional order of a country,but rather to the convergence of international law and domestic law through the constitutional order.The relevant rules of international law will be effective only when they are transformed into domestic law through the Constitution and the human rights clause in the Constitution.Correspondingly,the domestic legal order is brought into line with the international legal order through the Con-stitution and its human rights clause.Behind the system of fundamen-tal rights in the constitutional order is the value foundation of the en-tire legal system.The advancement of foreign-related rule of law has brought new opportunities for China’s judicial practice to further pro-mote the protection of human rights.In the future,we should further integrate the human rights values embedded in socialism into China’s constitutional practice,enhance human rights protection around the country,and take a more active part in global human rights gover-nance. 展开更多
关键词 human rights clause foreign-related rule of law socialist constitution constitutionalization of human rights
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Inverse design of mechanical metamaterial achieving a prescribedconstitutive curve 被引量:1
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作者 Zongliang Du Tanghuai Bian +4 位作者 Xiaoqiang Ren Yibo Jia Shan Tang Tianchen Cui Xu Guo 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2024年第1期16-22,共7页
Besides exhibiting excellent capabilities such as energy absorption,phase-transforming metamaterials offer a vast design space for achieving nonlinear constitutive relations.This is facilitated by switching between di... Besides exhibiting excellent capabilities such as energy absorption,phase-transforming metamaterials offer a vast design space for achieving nonlinear constitutive relations.This is facilitated by switching between different patterns under deformation.However,the related inverse design problem is quite challenging,due to the lack of appropriate mathematical formulation and the convergence issue in the post-buckling analysis of intermediate designs.In this work,periodic unit cells are explicitly described by the moving morphable voids method and effectively analyzed by eliminating the degrees of freedom in void regions.Furthermore,by exploring the Pareto frontiers between error and cost,an inverse design formulation is proposed for unit cells.This formulation aims to achieve a prescribed constitutive curve and is validated through numerical examples and experimental results.The design approach presented here can be extended to the inverse design of other types of mechanical metamaterials with prescribed nonlinear effective properties. 展开更多
关键词 METAMATERIAL Pattern-transformation constitutive curve Inverse design
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Time-domain dynamic constitutive model suitable for mucky soil site seismic response 被引量:1
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作者 Dong Qing Chen Su +2 位作者 Jin Liguo Zhou Zhenghua Li Xiaojun 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2024年第1期1-13,共13页
Soil nonlinear behavior displays noticeable effects on the site seismic response.This study proposes a new functional expression of the skeleton curve to replace the hyperbolic skeleton curve.By integrating shear modu... Soil nonlinear behavior displays noticeable effects on the site seismic response.This study proposes a new functional expression of the skeleton curve to replace the hyperbolic skeleton curve.By integrating shear modulus and combining the dynamic skeleton curve and the damping degradation coefficient,the constitutive equation of the logarithmic dynamic skeleton can be obtained,which considers the damping effect in a soil dynamics problem.Based on the finite difference method and the multi-transmitting boundary condition,a 1D site seismic response analysis program called Soilresp1D has been developed herein and used to analyze the time-domain seismic response in three types of sites.At the same time,this study also provides numerical simulation results based on the hyperbolic constitutive model and the equivalent linear method.The results verify the rationality of the new soil dynamic constitutive model.It can analyze the mucky soil site nonlinear seismic response,reflecting the deformation characteristics and damping effect of the silty soil.The hysteresis loop area is more extensive,and the residual strain is evident. 展开更多
关键词 seismic response time-domain dynamic constitutive model logarithmic dynamic skeleton dampening effect mucky soil
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Damage constitutive model of lunar soil simulant geopolymer under impact loading 被引量:2
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作者 Hanyan Wang Qinyong Ma Qianyun Wu 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第3期1059-1071,共13页
Lunar base construction is a crucial component of the lunar exploration program,and considering the dynamic characteristics of lunar soil is important for moon construction.Therefore,investigating the dynamic properti... Lunar base construction is a crucial component of the lunar exploration program,and considering the dynamic characteristics of lunar soil is important for moon construction.Therefore,investigating the dynamic properties of lunar soil by establishing a constitutive relationship is critical for providing a theoretical basis for its damage evolution.In this paper,a split Hopkinson pressure bar(SHPB)device was used to perform three sets of impact tests under different pressures on a lunar soil simulant geopolymer(LSSG)with sodium silicate(Na_(2)SiO_(3))contents of 1%,3%,5%and 7%.The dynamic stressestrain curves,failure modes,and energy variation rules of LSSG under different pressures were obtained.The equation was modified based on the ZWT viscoelastic constitutive model and was combined with the damage variable.The damage element obeys the Weibull distribution and the constitutive equation that can describe the mechanical properties of LSSG under dynamic loading was obtained.The results demonstrate that the dynamic compressive strength of LSSG has a marked strain-rate strengthening effect.Na_(2)SiO_(3) has both strengthening and deterioration effects on the dynamic compressive strength of LSSG.As Na_(2)SiO_(3) grows,the dynamic compressive strength of LSSG first increases and then decreases.At a fixed air pressure,5%Na_(2)SiO_(3) had the largest dynamic compressive strength,the largest incident energy,the smallest absorbed energy,and the lightest damage.The ZWT equation was modified according to the stress response properties of LSSG and the range of the SHPB strain rate to obtain the constitutive equation of the LSSG,and the model’s correctness was confirmed. 展开更多
关键词 Lunar soil simulant geopolymer(LSSG) Split hopkinson pressure bar(SHPB)test constitutive model Energy analysis Failure mode
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Constitutional Nature of Personality Rights and Its Manifestation in Civil Law
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作者 陈斯彬 《The Journal of Human Rights》 2023年第4期804-825,共22页
The formation of personality comes from people’s choices and pursuit of self-realization,which is influenced by objective factors but not determined by them,so personality does not belong to the domain of objectivity... The formation of personality comes from people’s choices and pursuit of self-realization,which is influenced by objective factors but not determined by them,so personality does not belong to the domain of objectivity.The concept of general personality rights in the German Constitution was initially premised on the objective determinability in the field of personality,but in constitutional jurisprudence,it gradually shifted to something with individual autonomy as the core and personal self-realization as the goal,and the scope of relevant rights expanded accordingly,so that they could not be clearly distinguished from general freedom of action and thus became the general principle of constitutional rights.The protection of constitutional personality rights in the United States and Japan can also confirm this process,providing evidence for the constitutional nature of personality rights.Deeper research shows that constitutional personality rights actually manifest the highest value of modern constitutions—human dignity.In contrast,the theoretical justification of personality rights in civil law just lies in the objectivity and defensive nature of personality elements. 展开更多
关键词 general personality rights constitutional personality rights SELF-REALIZATION SELF-DETERMINATION human dignity
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Development and Application of a Power Law Constitutive Model for Eddy Current Dampers
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作者 Longteng Liang Zhouquan Feng +2 位作者 Hongyi Zhang Zhengqing Chen Changzhao Qian 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第3期2403-2419,共17页
Eddy current dampers (ECDs) have emerged as highly desirable solutions for vibration control due to theirexceptional damping performance and durability. However, the existing constitutive models present challenges tot... Eddy current dampers (ECDs) have emerged as highly desirable solutions for vibration control due to theirexceptional damping performance and durability. However, the existing constitutive models present challenges tothe widespread implementation of ECD technology, and there is limited availability of finite element analysis (FEA)software capable of accurately modeling the behavior of ECDs. This study addresses these issues by developing anewconstitutivemodel that is both easily understandable and user-friendly for FEAsoftware. By utilizing numericalresults obtained from electromagnetic FEA, a novel power law constitutive model is proposed to capture thenonlinear behavior of ECDs. The effectiveness of the power law constitutive model is validated throughmechanicalproperty tests and numerical seismic analysis. Furthermore, a detailed description of the application process ofthe power law constitutive model in ANSYS FEA software is provided. To facilitate the preliminary design ofECDs, an analytical derivation of energy dissipation and parameter optimization for ECDs under harmonicmotionis performed. The results demonstrate that the power law constitutive model serves as a viable alternative forconducting dynamic analysis using FEA and optimizing parameters for ECDs. 展开更多
关键词 Eddy current damper constitutive model finite element analysis vibration control power law constitutive model
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Why The Constitution Should Protect Personal Credit Information?——An Approach of Right Argumentation
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作者 李艺 SU Yilon 《The Journal of Human Rights》 2023年第2期328-346,共19页
Protecting personal credit information through constitutional rights is not only essemtial for individuals to defend against infringements on their personal credit information rights and interests by public power in t... Protecting personal credit information through constitutional rights is not only essemtial for individuals to defend against infringements on their personal credit information rights and interests by public power in the social credit system,but also a requirement for unified legislation on social credit to explore the basis for constitutional norms.In the era of the credit economy,personal credit information has become a vital resource for realizing personal autonomy.Along with the increase in the state’s supervision and control of personal credit,the realization of the autonomous value in the interests related to personal credit information has also set more obligations for the state.Therefore,interests related to personal credit information should be regarded as a constitutional right.Because of its significant economic interest and value,the right to personal credit information should be classified as a constitutional property right.As a constitutional property right,the right to personal credit information can not only help protect people’s economic interests,but also achieve the goal of safeguarding their personality interests. 展开更多
关键词 right to personal credit information constitutional rights social and economic rights property rights
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A macro-mesoscopic constitutive model for porous and cracked rock under true triaxial conditions
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作者 Li Qian Zuguo Mo +4 位作者 Jianhai Zhang Xianglin Xing Ru Zhang Tianzhi Yao Yunpeng Gao 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第8期3080-3098,共19页
The complex mechanical and damage mechanisms of rocks are intricately tied to their diverse mineral compositions and the formation of pores and cracks under external loads.Numerous rock tests reveal a complex interpla... The complex mechanical and damage mechanisms of rocks are intricately tied to their diverse mineral compositions and the formation of pores and cracks under external loads.Numerous rock tests reveal a complex interplay between the closure of porous defects and the propagation of induced cracks,presenting challenges in accurately representing their mechanical properties,especially under true triaxial stress conditions.This paper proposes a conceptualization of rock at the mesoscopic level as a two-phase composite,consisting of a bonded medium matrix and frictional medium inclusions.The bonded medium is characterized as a mesoscopic elastic material,encompassing various minerals surrounding porous defects.Its mechanical properties are determined using the mixed multi-inclusion method.Transformation of the bonded medium into the frictional medium occurs through crack extension,with its elastoplastic properties defined by the DruckerePrager yield criterion,accounting for hardening,softening,and extension.MorieTanaka and Eshelby’s equivalent inclusion methods are applied to the bonded and frictional media,respectively.The macroscopic mechanical properties of the rock are derived from these mesoscopic media.Consequently,a True Triaxial Macro-Mesoscopic(TTMM)constitutive model is developed.This model effectively captures the competitive effect and accurately describes the stress-deformation characteristics of granite.Utilizing the TTMM model,the strains resulting from porous defect closure and induced crack extension are differentiated,enabling quantitative determination of the associated damage evolution. 展开更多
关键词 MICROMECHANICS Macroemesoscopic HOMOGENIZATION constitutive model Competitive effect
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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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A whole process damage constitutive model for layered sandstone under uniaxial compression based on Logistic function
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作者 LIU Dong-qiao GUO Yun-peng +1 位作者 LING Kai LI Jie-yu 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第7期2411-2430,共20页
Bedding structural planes significantly influence the mechanical properties and stability of engineering rock masses.This study conducts uniaxial compression tests on layered sandstone with various bedding angles(0... Bedding structural planes significantly influence the mechanical properties and stability of engineering rock masses.This study conducts uniaxial compression tests on layered sandstone with various bedding angles(0°,15°,30°,45°,60°,75°and 90°)to explore the impact of bedding angle on the deformational mechanical response,failure mode,and damage evolution processes of rocks.It develops a damage model based on the Logistic equation derived from the modulus’s degradation considering the combined effect of the sandstone bedding dip angle and load.This model is employed to study the damage accumulation state and its evolution within the layered rock mass.This research also introduces a piecewise constitutive model that considers the initial compaction characteristics to simulate the whole deformation process of layered sandstone under uniaxial compression.The results revealed that as the bedding angle increases from 0°to 90°,the uniaxial compressive strength and elastic modulus of layered sandstone significantly decrease,slightly increase,and then decline again.The corresponding failure modes transition from splitting tensile failure to slipping shear failure and back to splitting tensile failure.As indicated by the modulus’s degradation,the damage characteristics can be categorized into four stages:initial no damage,damage initiation,damage acceleration,and damage deceleration termination.The theoretical damage model based on the Logistic equation effectively simulates and predicts the entire damage evolution process.Moreover,the theoretical constitutive model curves closely align with the actual stress−strain curves of layered sandstone under uniaxial compression.The introduced constitutive model is concise,with fewer parameters,a straightforward parameter determination process,and a clear physical interpretation.This study offers valuable insights into the theory of layered rock mechanics and holds implications for ensuring the safety of rock engineering. 展开更多
关键词 layered sandstone uniaxial compression damage evolution Logistic function constitutive model
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An improved strain-softening constitutive model of granite considering the effect of crack deformation
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作者 Yapeng Li Qiang Zhang +2 位作者 Qiuxin Gu Peinan Wu Binsong Jiang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第4期1202-1215,共14页
This paper presents an improved strain-softening constitutive model considering the effect of crack deformation based on the triaxial cyclic loading and unloading test results.The improved model assumes that total str... This paper presents an improved strain-softening constitutive model considering the effect of crack deformation based on the triaxial cyclic loading and unloading test results.The improved model assumes that total strain is a combination of plastic,elastic,and crack strains.The constitutive relationship between the crack strain and the stress was further derived.The evolutions of mechanical parameters,i.e.strength parameters,dilation angle,unloading elastic modulus,and deformation parameters of crack,with the plastic strain and confining pressure were studied.With the increase in plastic strain,the cohesion,friction angle,dilation angle,and crack Poisson's ratio initially increase and subsequently decrease,and the unloading elastic modulus and the crack elastic modulus nonlinearly decrease.The increasing confining pressure enhances the strength and unloading elastic modulus,and decreases the dilation angle and Poisson's ratio of the crack.The theoretical triaxial compressive stress-strain curves were compared with the experimental results,and they present a good agreement with each other.The improved constitutive model can well reflect the nonlinear mechanical behavior of granite. 展开更多
关键词 STRAIN-SOFTENING Crack deformation effect Plastic shear strain constitutive model
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Novel damage constitutive models and new quantitative identification method for stress thresholds of rocks under uniaxial compression
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作者 DU Kun YI Yang +3 位作者 LUO Xin-yao LIU Kai LI Peng WANG Shao-feng 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第8期2658-2675,共18页
Four key stress thresholds exist in the compression process of rocks,i.e.,crack closure stress(σ_(cc)),crack initiation stress(σ_(ci)),crack damage stress(σ_(cd))and compressive strength(σ_(c)).The quantitative id... Four key stress thresholds exist in the compression process of rocks,i.e.,crack closure stress(σ_(cc)),crack initiation stress(σ_(ci)),crack damage stress(σ_(cd))and compressive strength(σ_(c)).The quantitative identifications of the first three stress thresholds are of great significance for characterizing the microcrack growth and damage evolution of rocks under compression.In this paper,a new method based on damage constitutive model is proposed to quantitatively measure the stress thresholds of rocks.Firstly,two different damage constitutive models were constructed based on acoustic emission(AE)counts and Weibull distribution function considering the compaction stages of the rock and the bearing capacity of the damage element.Then,the accumulative AE counts method(ACLM),AE count rate method(CRM)and constitutive model method(CMM)were introduced to determine the stress thresholds of rocks.Finally,the stress thresholds of 9 different rocks were identified by ACLM,CRM,and CMM.The results show that the theoretical stress−strain curves obtained from the two damage constitutive models are in good agreement with that of the experimental data,and the differences between the two damage constitutive models mainly come from the evolutionary differences of the damage variables.The results of the stress thresholds identified by the CMM are in good agreement with those identified by the AE methods,i.e.,ACLM and CRM.Therefore,the proposed CMM can be used to determine the stress thresholds of rocks. 展开更多
关键词 stress threshold acoustic emission damage constitutive model damage element quantitative method
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Enhancing constitutive description and workability characterization of Mg alloy during hot deformation using machine learning-based Arrhenius-type model
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作者 Jinchuan Long Lei Deng +6 位作者 Junsong Jin Mao Zhang Xuefeng Tang Pan Gong Xinyun Wang Gangfeng Xiao Qinxiang Xia 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第7期3003-3023,共21页
Hot deformation is a commonly employed processing technique to enhance the ductility and workability of Mg alloy.However,the hot deformation of Mg alloy is highly sensitive to factors such as temperature,strain rate,a... Hot deformation is a commonly employed processing technique to enhance the ductility and workability of Mg alloy.However,the hot deformation of Mg alloy is highly sensitive to factors such as temperature,strain rate,and strain,leading to complex flow behavior and an exceptionally narrow processing window for Mg alloy.To overcome the shortcomings of the conventional Arrhenius-type(AT)model,this study developed machine learning-based Arrhenius-type(ML-AT)models by combining the genetic algorithm(GA),particle swarm optimization(PSO),and artificial neural network(ANN).Results indicated that when describing the flow behavior of the AQ80 alloy,the PSO-ANN-AT model demonstrates the most prominent prediction accuracy and generalization ability among all ML-AT and AT models.Moreover,an activation energy-processing(AEP)map was established using the reconstructed flow stress and activation energy fields based on the PSO-ANN-AT model.Experimental validations revealed that this AEP map exhibits superior predictive capability for microstructure evolution compared to the one established by the traditional interpolation methods,ultimately contributing to the precise determination of the optimum processing window.These findings provide fresh insights into the accurate constitutive description and workability characterization of Mg alloy during hot deformation. 展开更多
关键词 constitutive description Workability characterization Machine learning Mg alloy Hot deformation
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Fatigue properties and damage constitutive model of salt rock based on CT scanning
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作者 Junbao Wang Xiao Liu +3 位作者 Qiang Zhang Xinrong Liu Zhanping Song Shijin Feng 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第2期245-259,共15页
To investigate the macroscopic fatigue properties and the mesoscopic pore evolution characteristics of salt rock under cyclic loading,fatigue tests under different upper-limit stresses were carried out on salt rock,an... To investigate the macroscopic fatigue properties and the mesoscopic pore evolution characteristics of salt rock under cyclic loading,fatigue tests under different upper-limit stresses were carried out on salt rock,and the mesoscopic pore structures of salt rock before and after fatigue tests and under different cycle numbers were measured using CT scanning instrument.Based on the test results,the effects of the cycle number and the upper-limit stress on the evolution of cracks,pore morphology,pore number,pore volume,pore size,plane porosity,and volume porosity of salt rock were analyzed.The failure path of salt rock specimens under cyclic loading was analyzed using the distribution law of plane porosity.The damage variable of salt rock under cyclic loading was defined on basis of the variation of volume porosity with cycle number.In order to describe the fatigue deformation behavior of salt rock under cyclic loading,the nonlinear Burgers damage constitutive model was further established.The results show that the model established can better reflect the whole development process of fatigue deformation of salt rock under cyclic loading. 展开更多
关键词 Salt rock Cyclic loading CT scanning Mesoscopic pore evolution constitutive model
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Experiment and constitutive modelling of creep deformation in the frozen silt-concrete interface
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作者 HE Fei LIU Qingquan +4 位作者 LEI Wanyu WANG Xu MAO Erqing LI Sheng CHEN Hangjie 《Journal of Mountain Science》 SCIE CSCD 2024年第9期3172-3185,共14页
To ensure the long-term safety and stability of bridge pile foundations in permafrost regions,it is necessary to investigate the rheological effects on the pile tip and pile side bearing capacities.The creep character... To ensure the long-term safety and stability of bridge pile foundations in permafrost regions,it is necessary to investigate the rheological effects on the pile tip and pile side bearing capacities.The creep characteristics of the pile-frozen soil interface are critical for determining the long-term stability of permafrost pile foundations.This study utilized a self-developed large stress-controlled shear apparatus to investigate the shear creep characteristics of the frozen silt-concrete interface,and examined the influence of freezing temperatures(−1,−2,and−5°C),contact surface roughness(0,0.60,0.75,and 1.15 mm),normal stress(50,100,and 150 kPa),and shear stress on the creep characteristics of the contact surface.By incorporating the contact surface’s creep behavior and development trends,we established a creep constitutive model for the frozen silt-concrete interface based on the Nishihara model,introducing nonlinear elements and a damage factor.The results revealed significant creep effects on the frozen silt-concrete interface under constant load,with creep displacement at approximately 2-15 times the instantaneous displacement and a failure creep displacement ranging from 6 to 8 mm.Under different experimental conditions,the creep characteristics of the frozen silt-concrete interface varied.A larger roughness,lower freezing temperatures,and higher normal stresses resulted in a longer sample attenuation creep time,a lower steady-state creep rate,higher long-term creep strength,and stronger creep stability.Building upon the Nishihara model,we considered the influence of shear stress and time on the viscoelastic viscosity coefficient and introduced a damage factor to the viscoplasticity.The improved model effectively described the entire creep process of the frozen silt-concrete interface.The results provide theoretical support for the interaction between pile and soil in permafrost regions. 展开更多
关键词 Creep characteristics Contact surface Frozen silt constitutive model Freezing temperature
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Constitutive model of viscoelastic dynamic damage for the material of gas obturator in modular-charge howitzer
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作者 Zhonggang Li Longmiao Chen +2 位作者 Yifan Li Yufeng Jia Quan Zhang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第9期203-216,共14页
In order to investigate the mechanical response behavior of the gas obturator of the breech mechanism,made of polychloroprene rubber(PCR), uniaxial compression experiments were carried out by using a universal testing... In order to investigate the mechanical response behavior of the gas obturator of the breech mechanism,made of polychloroprene rubber(PCR), uniaxial compression experiments were carried out by using a universal testing machine and a split Hopkinson pressure bar(SHPB), obtaining stress-strain responses at different temperatures and strain rates. The results revealed that, in comparison to other polymers, the gas obturator material exhibited inconspicuous strain softening and hardening effects;meanwhile, the mechanical response was more affected by the strain rate than by temperature. Subsequently, a succinct viscoelastic damage constitutive model was developed based on the ZWT model, including ten undetermined parameters, formulated with incorporating three parallel components to capture the viscoelastic response at high strain rate and further enhanced by integrating a three-parameter Weibull function to describe the damage. Compared to the ZWT model, the modified model could effectively describe the mechanical response behavior of the gas obturator material at high strain rates. This research laid a theoretical foundation for further investigation into the influence of chamber sealing issues on artillery firing. 展开更多
关键词 Breech mechanism Gas obturator Polychloroprene rubber constitutive model Strain rate Damage
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The Concept of Human Rights in the Constitution and Its Functional Significance
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作者 严海良 CHEN Feng 《The Journal of Human Rights》 2023年第1期56-90,共35页
To practice the constitutional provision that “The state respects and protects human rights”, we should clarify its connotation. The understanding of human rights is a natural requirement and the key. In domestic ac... To practice the constitutional provision that “The state respects and protects human rights”, we should clarify its connotation. The understanding of human rights is a natural requirement and the key. In domestic academia, human rights are considered natural rights and interpreted as “moral rights that everyone should enjoy as a human being”, hoping to provide theoretical support for the development of the system centered on the basic rights of citizens in China.Although it reveals the universal moral connotation of human rights, it does not cover the normative connotation of human rights as common international standards. Therefore, it is impossible to fully clarify the functional significance of the provision. It is conducive to scientifically clarifying the relationship between human rights and basic civil rights,better improving the institutional protection of human rights in China,and promoting the building of a community with a shared future for mankind to interpret human rights as common international standards that everyone should enjoy for human dignity based on the development of the international legal order under the Charter of the United Nations since the end of the World War Ⅱ. 展开更多
关键词 human rights constitutional rights international law common standards
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