Objective: This study aimed to explore the structural and functional characteristics of the fecalassociated microbiome(FAM) between the phlegm-dampness constitution(PDC) and balanced constitution(BC), and to screen th...Objective: This study aimed to explore the structural and functional characteristics of the fecalassociated microbiome(FAM) between the phlegm-dampness constitution(PDC) and balanced constitution(BC), and to screen the related specific operational taxonomic unit(OTU) biomarkers.Methods: This was a cross-sectional study. After strictly identifying the constitution of subjects, their clinical index was recorded and counted. Fecal samples were collected for 16S rDNA sequencing. Alpha diversity, beta diversity, and the relative abundance of dominant bacterial taxa were used to describe the FAM structure, and the Wilcoxon rank-sum test, Metagenome Seq, and linear discriminant analysis effect size(LEf Se) were used to screen specific bacterial taxa. Specific OTUs were screened to construct receiver operating characteristic(ROC) curves.Results: Thirty-two subjects were enrolled, including 22 subjects with BC and 10 subjects with PDC.There were significant differences in cold preference, levels of aspartate transaminase, β2-microglobulin,and creatine kinase MB, and alpha diversity indices(Shannon and Shannoneven) between the two groups. In principal coordinate analysis by abund-jaccard distance measure and partial least squares discriminant analysis, bacterial communities clustered separately between the two groups. Furthermore,based on Metagenome Seq, LEf Se, and the Wilcoxon rank-sum test, a total of 43, 18, and 130 OTUs were differentially distributed between BC group and PDC group, respectively, and OTU200, OTU133, and OTU353 were screened when P≤.01. The area under the ROC curve constructed from the 3 selected OTUs was 0.93.Conclusion: The FAM structure and related functional characteristics of the PDC group differed from those of the BC group. In particular, OTU200, OTU133, and OTU353 can be used as unique markers of PDC to assist clinical diagnosis.展开更多
Objective:To observe the clinical effects of"hand and foot 12 needle acupuncture"on stroke in convalescent period of phlegm-dampness constitution.Methods:The 90 patients were divided into the treatment group...Objective:To observe the clinical effects of"hand and foot 12 needle acupuncture"on stroke in convalescent period of phlegm-dampness constitution.Methods:The 90 patients were divided into the treatment group(n=45)and the control group(n=45)according to the random number table method.The control group received basic Western medicine treatment+rehabilitation treatment of Western medicine,and the treatment group was additively treated with"hand and foot 12 needle acupuncture"on the basis of the control group.NIHSS score,MRS score and Barthel index(BI)before and after treatment were observed in the two groups,and the clinical efficacy of the two groups was compared.Results:The clinical efficacy of stroke patients in the convalescent period of phlegm-dampness constitution after treatment:the total effective rate of the treatment group was 93.33%,and the total effective rate of the control group was 66.67%.After statistical processing,the clinical efficacy of the treatment group was significantly better than the control group;NIHSS score,MRS score and Barthel index(BI)were better than the control group,and the differences were statistically significant(P<0.05).Conclusion:"Hand and foot 12 needle acupuncture"treatment of phlegm-dampness constitution convalescent stroke clinical effect is remarkable.展开更多
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
OBJECTIVE:To evaluate the extent of vascular endothelial dysfunction and preliminary identify serum protein biomarkers associated with obese individuals at risk for cardiovascular disease(CVD).METHODS:Fifteen obese vo...OBJECTIVE:To evaluate the extent of vascular endothelial dysfunction and preliminary identify serum protein biomarkers associated with obese individuals at risk for cardiovascular disease(CVD).METHODS:Fifteen obese volunteers with the phlegmdampness constitution or balanced constitution were recruited for this study respectively.The clinical baseline data was collected,and the vascular endothelial function was evaluated using the EndoPAT?.Blood samples were collected for the serum proteome analysis.The differences in the serum protein expression levels between the two groups were detected and the protein interaction network analysis,correlation analysis,receiver operating characteristic(ROC)curve analysis,and random forest model investigation were conducted.RESULTS:There were no statistical differences found in the baseline data.For vascular endothelial function,the reactive hyperemia index(RHI)of the phlegm-dampness constitution obese group was significantly lower than that of the balanced constitution obese group(1.46±0.30 vs 2.82±0.78,P<0.0001),indicating vascular endothelial dysfunction.There are 66 differentially expressed serum proteins between the two groups.apolipoprotein A2(Apo A2),angiotensin-converting enzyme 2(ACE-2),interleukin-33(IL-33),and forkhead box P3(FoxP3)showed significant differences and area under curve values of their ROC curves were greater than 0.7 and correlated significantly with RHI.CONCLUSION:Vascular endothelial dysfunction was present in the phlegm-dampness constitution obese group.Thus,alterations in the expression levels of key serum proteins,including Apo A2,ACE-2,IL-33,and Fox P3 could serve as potential biomarkers in the obese population at risk of CVD.展开更多
Objective： To explore the polymorphism of low density lipoprotein receptor （LDL-R） genes Pvu Ⅱ end Ave Ⅱ in e population with phlegm-dampness constitution （PDC）. Methods： Polymorphism of LDL-R genes at Pvu Ⅱ ...Objective： To explore the polymorphism of low density lipoprotein receptor （LDL-R） genes Pvu Ⅱ end Ave Ⅱ in e population with phlegm-dampness constitution （PDC）. Methods： Polymorphism of LDL-R genes at Pvu Ⅱ end Ave Ⅱ of 48 persons with gentle constitution （GC） end 61 with PDC were analyzed with PCR-RELP technique, end their serum contents of lipids end glucose were determined end compared as well. Results： The A＋ ellelic end P- ellelic frequency were higher end the P＋ ellelic frequency was lower in subjects with PDC then those in subjects with GC, which were 0.3083 vs 0.1771, 0.9098 vs 0.7708 end 0.0902 vs 0.2292, respectively, ell showing significant difference between the two groups （P〈0.05）. Comparison of the two groups in serum levels of triglyceride （TG）, fasting blood glucose, 2 h postprandial blood glucose, end 2 h postprandial insulin showed that ell the parameters were higher in subjects with PDC then in subjects with GC respectively, showing significant difference （P〈0.05）. Conclusion： PDC is related with the P- end A＋ ellelic frequency of higher LDL-R genes at Pvu Ⅱ end Ave Ⅱ, therefore, the polymorphism of LDL-R genes could be taken as one of the genetic markers for PDC, end humans with PDC ere more liable to suffer from blood lipids end glucose disorder then those with GC.展开更多
Objective:We aim to investigate the effects of different exercise intensities and volumes on Phlegm-dampness constitution(PDC).Methods:The rats were fed with high-fat food and lived in 75%–85%humidity for 6 weeks to ...Objective:We aim to investigate the effects of different exercise intensities and volumes on Phlegm-dampness constitution(PDC).Methods:The rats were fed with high-fat food and lived in 75%–85%humidity for 6 weeks to establish the model of PDC.Then PDC rats were screened and intervened by varying exercise intensities for 8 weeks.Weight,constitution scores,blood and liver tissues were collected to detect the concentration of serum total cholesterol(Tch),triglyceride(TG),low-density lipoprotein cholesterol(LDL-C),high-density lipoprotein cholesterol(HDL-C),homocysteine(Hcy),blood glucose(GLU),alanine transaminase(ALT)and percentage of lipid droplet area in liver tissue(PLDA).Results:The weight,Tch,TG,HDL-C,LDL-C,Hcy,GLU,and ALT of rats in moderate-intensity exercise group returned to normal.The rats with high-intensity or low-intensity exercise did not recover as well as moderate-intensity.Conclusion:Different exercise intensities and volumes have different effects on PDC,moderate-intensity exercise over an 8-week intervention is most appropriate.展开更多
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
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
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
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
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
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
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
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
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
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
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
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
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
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
基金supported by National Natural Science Foundation of China (81430099)National Key Research and Development Project (2019YFC1710104)the 111 Project (B21028)。
文摘Objective: This study aimed to explore the structural and functional characteristics of the fecalassociated microbiome(FAM) between the phlegm-dampness constitution(PDC) and balanced constitution(BC), and to screen the related specific operational taxonomic unit(OTU) biomarkers.Methods: This was a cross-sectional study. After strictly identifying the constitution of subjects, their clinical index was recorded and counted. Fecal samples were collected for 16S rDNA sequencing. Alpha diversity, beta diversity, and the relative abundance of dominant bacterial taxa were used to describe the FAM structure, and the Wilcoxon rank-sum test, Metagenome Seq, and linear discriminant analysis effect size(LEf Se) were used to screen specific bacterial taxa. Specific OTUs were screened to construct receiver operating characteristic(ROC) curves.Results: Thirty-two subjects were enrolled, including 22 subjects with BC and 10 subjects with PDC.There were significant differences in cold preference, levels of aspartate transaminase, β2-microglobulin,and creatine kinase MB, and alpha diversity indices(Shannon and Shannoneven) between the two groups. In principal coordinate analysis by abund-jaccard distance measure and partial least squares discriminant analysis, bacterial communities clustered separately between the two groups. Furthermore,based on Metagenome Seq, LEf Se, and the Wilcoxon rank-sum test, a total of 43, 18, and 130 OTUs were differentially distributed between BC group and PDC group, respectively, and OTU200, OTU133, and OTU353 were screened when P≤.01. The area under the ROC curve constructed from the 3 selected OTUs was 0.93.Conclusion: The FAM structure and related functional characteristics of the PDC group differed from those of the BC group. In particular, OTU200, OTU133, and OTU353 can be used as unique markers of PDC to assist clinical diagnosis.
基金Research and Cultivation Program of Beijing Municipal Hospital(Project No.:PZ2018007)。
文摘Objective:To observe the clinical effects of"hand and foot 12 needle acupuncture"on stroke in convalescent period of phlegm-dampness constitution.Methods:The 90 patients were divided into the treatment group(n=45)and the control group(n=45)according to the random number table method.The control group received basic Western medicine treatment+rehabilitation treatment of Western medicine,and the treatment group was additively treated with"hand and foot 12 needle acupuncture"on the basis of the control group.NIHSS score,MRS score and Barthel index(BI)before and after treatment were observed in the two groups,and the clinical efficacy of the two groups was compared.Results:The clinical efficacy of stroke patients in the convalescent period of phlegm-dampness constitution after treatment:the total effective rate of the treatment group was 93.33%,and the total effective rate of the control group was 66.67%.After statistical processing,the clinical efficacy of the treatment group was significantly better than the control group;NIHSS score,MRS score and Barthel index(BI)were better than the control group,and the differences were statistically significant(P<0.05).Conclusion:"Hand and foot 12 needle acupuncture"treatment of phlegm-dampness constitution convalescent stroke clinical effect is remarkable.
基金This work was supported by the National Natural Science Foundation of China(81730112&81874413)Scientific Research and Innovation Team of Beijing University of Chinese Medicine(2019-JYB-TD010).
文摘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.
基金Supported by General Program of National Natural Science of China:Qigui Slimming Prescription Upgrades the Activating Ability of the Phlegm-Dampness Constitution to Improve Obesity by Regulating the Thermogenesis Axis of Clostridium Enterica-PhytosphingosineSph K/S1P-Ca^(2+) Cycle(No.82374308)National Key Research and Development Program:Development of Dietary Intervention Series for the Elderly with Decreased Functionality(No.2022YFC2010104)National Nonprofit Institute Research Grant for Institute of Basic Theory for Chinese Medicine,CACMS:Methylation of Gut Microbiota-Host DNA Reveals the Mechanism of Promoting PhlegmDampness Constitution to Prevent Metabolic Diseases(No.YZ-202151)。
文摘OBJECTIVE:To evaluate the extent of vascular endothelial dysfunction and preliminary identify serum protein biomarkers associated with obese individuals at risk for cardiovascular disease(CVD).METHODS:Fifteen obese volunteers with the phlegmdampness constitution or balanced constitution were recruited for this study respectively.The clinical baseline data was collected,and the vascular endothelial function was evaluated using the EndoPAT?.Blood samples were collected for the serum proteome analysis.The differences in the serum protein expression levels between the two groups were detected and the protein interaction network analysis,correlation analysis,receiver operating characteristic(ROC)curve analysis,and random forest model investigation were conducted.RESULTS:There were no statistical differences found in the baseline data.For vascular endothelial function,the reactive hyperemia index(RHI)of the phlegm-dampness constitution obese group was significantly lower than that of the balanced constitution obese group(1.46±0.30 vs 2.82±0.78,P<0.0001),indicating vascular endothelial dysfunction.There are 66 differentially expressed serum proteins between the two groups.apolipoprotein A2(Apo A2),angiotensin-converting enzyme 2(ACE-2),interleukin-33(IL-33),and forkhead box P3(FoxP3)showed significant differences and area under curve values of their ROC curves were greater than 0.7 and correlated significantly with RHI.CONCLUSION:Vascular endothelial dysfunction was present in the phlegm-dampness constitution obese group.Thus,alterations in the expression levels of key serum proteins,including Apo A2,ACE-2,IL-33,and Fox P3 could serve as potential biomarkers in the obese population at risk of CVD.
基金Supported by the State Administration of TCM (No.2003LHR18)
文摘Objective： To explore the polymorphism of low density lipoprotein receptor （LDL-R） genes Pvu Ⅱ end Ave Ⅱ in e population with phlegm-dampness constitution （PDC）. Methods： Polymorphism of LDL-R genes at Pvu Ⅱ end Ave Ⅱ of 48 persons with gentle constitution （GC） end 61 with PDC were analyzed with PCR-RELP technique, end their serum contents of lipids end glucose were determined end compared as well. Results： The A＋ ellelic end P- ellelic frequency were higher end the P＋ ellelic frequency was lower in subjects with PDC then those in subjects with GC, which were 0.3083 vs 0.1771, 0.9098 vs 0.7708 end 0.0902 vs 0.2292, respectively, ell showing significant difference between the two groups （P〈0.05）. Comparison of the two groups in serum levels of triglyceride （TG）, fasting blood glucose, 2 h postprandial blood glucose, end 2 h postprandial insulin showed that ell the parameters were higher in subjects with PDC then in subjects with GC respectively, showing significant difference （P〈0.05）. Conclusion： PDC is related with the P- end A＋ ellelic frequency of higher LDL-R genes at Pvu Ⅱ end Ave Ⅱ, therefore, the polymorphism of LDL-R genes could be taken as one of the genetic markers for PDC, end humans with PDC ere more liable to suffer from blood lipids end glucose disorder then those with GC.
文摘Objective:We aim to investigate the effects of different exercise intensities and volumes on Phlegm-dampness constitution(PDC).Methods:The rats were fed with high-fat food and lived in 75%–85%humidity for 6 weeks to establish the model of PDC.Then PDC rats were screened and intervened by varying exercise intensities for 8 weeks.Weight,constitution scores,blood and liver tissues were collected to detect the concentration of serum total cholesterol(Tch),triglyceride(TG),low-density lipoprotein cholesterol(LDL-C),high-density lipoprotein cholesterol(HDL-C),homocysteine(Hcy),blood glucose(GLU),alanine transaminase(ALT)and percentage of lipid droplet area in liver tissue(PLDA).Results:The weight,Tch,TG,HDL-C,LDL-C,Hcy,GLU,and ALT of rats in moderate-intensity exercise group returned to normal.The rats with high-intensity or low-intensity exercise did not recover as well as moderate-intensity.Conclusion:Different exercise intensities and volumes have different effects on PDC,moderate-intensity exercise over an 8-week intervention is most appropriate.
基金supported by the National Key R&D Program of China(2020YFC2003102).
文摘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.
基金National Key Research and Development Program of China(2022YFC3502302)National Natural Science Foundation of China(82074580)Graduate Research Innovation Program of Jiangsu Province(KYCX23_2078).
文摘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.
文摘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.
文摘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.
基金supported by the National Natural Science Foun-dation of China(Grant Nos.12002073 and 12372122)the National Key Research and Development Plan of China(Grant No.2020YFB 1709401)+2 种基金the Science Technology Plan of Liaoning Province(Grant No.2023JH2/101600044)the Liaoning Revitalization Talents Pro-gram(Grant No.XLYC2001003)111 Project of China(Grant No.B14013).
文摘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.
基金Major Program of the National Natural Science Foundation of China under Grant No.52192675 and the 111 Project of China under Grant No.D21001。
文摘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.
文摘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.
文摘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.
文摘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.
基金funding support from the National Natural Science Foundation of China(Grant No.U1965203)“Dynamic analysis method of complex rock underground engineering in the Hengduan Mountains”project(Grant No.P43419)the Sichuan University Postdoctoral Research Fund(Grant No.2023SCU12123).
文摘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.
文摘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.
基金Projects(52074299,41941018)supported by the National Natural Science Foundation of ChinaProject(2023JCCXSB02)supported by the Fundamental Research Funds for the Central Universities,China。
文摘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.
基金financially supported by the National Natural Science Foundation of China(Grant No.52074269).
文摘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.
基金Projects(2021RC3007,2020RC3090)supported by the Science and Technology Innovation Program of Hunan Province,ChinaProjects(52374150,52174099)supported by the National Natural Science Foundation of China。
文摘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.
