Objective The relationship between non-high-density lipoprotein(NHDL)cholesterol to high-density lipoprotein cholesterol(HDL-C)ratio(NHHR)and stoke remains unknown.This study aimed to evaluate the association between ...Objective The relationship between non-high-density lipoprotein(NHDL)cholesterol to high-density lipoprotein cholesterol(HDL-C)ratio(NHHR)and stoke remains unknown.This study aimed to evaluate the association between the adult NHHR and stroke occurrence in the United States of America(USA).Methods To clarify the relationship between the NHHR and stroke risk,this study used a multivariable logistic regression model and a restricted cubic spline(RCS)model to investigate the association between the NHHR and stroke,and data from the National Health and Nutrition Examination Survey(NHANES)from 2005 to 2018.Subgroup and sensitivity analyses were conducted to test the robustness of the results.Results This study included 29,928 adult participants,of which 1,165 participants had a history of stroke.Logistic regression analysis of variables demonstrated a positive association between NHHR and stroke(OR 1.24,95%CI:1.03-1.50,P=0.026).Compared with the lowest reference group of NHHR,participants in the second,third,and fourth quartile had a significantly increased risk of stroke after full adjustments(OR:1.35,95%CI:1.08-1.69)(OR:1.83,95%CI:1.42-2.36)(OR:2.04,95%CI:1.50-2.79).In the total population,a nonlinear dose-response relationship was observed between the NHHR and stroke risk(P non-linearity=0.002).This association remained significant in several subgroup analyses.Further investigation of the NHHR may enhance our understanding of stroke prevention and treatment.Conclusion Our findings suggest a positive correlation between the NHHR and an increased prevalence of stroke,potentially serving as a novel predictive factor for stroke.Timely intervention and management of the NHHR may effectively mitigate stroke occurrence.Prospective studies are required to validate this association and further explore the underlying biological mechanisms.展开更多
The umbilical,a key component in offshore energy extraction,plays a vital role in ensuring the stable operation of the entire production system.The extensive variety of cross-sectional components creates highly comple...The umbilical,a key component in offshore energy extraction,plays a vital role in ensuring the stable operation of the entire production system.The extensive variety of cross-sectional components creates highly complex layout combinations.Furthermore,due to constraints in component quantity and geometry within the cross-sectional layout,filler bodies must be incorporated to maintain cross-section performance.Conventional design approaches based on manual experience suffer from inefficiency,high variability,and difficulties in quantification.This paper presents a multi-level automatic filling optimization design method for umbilical cross-sectional layouts to address these limitations.Initially,the research establishes a multi-objective optimization model that considers compactness,balance,and wear resistance of the cross-section,employing an enhanced genetic algorithm to achieve a near-optimal layout.Subsequently,the study implements an image processing-based vacancy detection technique to accurately identify cross-sectional gaps.To manage the variability and diversity of these vacant regions,the research introduces a multi-level filling method that strategically selects and places filler bodies of varying dimensions,overcoming the constraints of uniform-size fillers.Additionally,the method incorporates a hierarchical strategy that subdivides the complex cross-section into multiple layers,enabling layer-by-layer optimization and filling.This approach reduces manufac-turing equipment requirements while ensuring practical production process feasibility.The methodology is validated through a specific umbilical case study.The results demonstrate improvements in compactness,balance,and wear resistance compared with the initial cross-section,offering novel insights and valuable references for filler design in umbilical cross-sections.展开更多
Objective:Postpartum nutrition plays a critical role in maternal recovery and long-term health.However,the nutritional status of working mothers in the postpartum period remains understudied.This study aimed to assess...Objective:Postpartum nutrition plays a critical role in maternal recovery and long-term health.However,the nutritional status of working mothers in the postpartum period remains understudied.This study aimed to assess the dietary quality of postpartum women in urban Beijing,identify occupational-related factors influencing their diet,and explore potential interventions to improve maternal nutrition during the postpartum period.Methods:In this cross-sectional analysis,554 women one year after delivery were recruited from ten community health centers.Sociodemographic,occupational and postpartum care variables were collected via questionnaire.Dietary intake over the preceding year was assessed using a food frequency questionnaire.The modified dietary balance index for postpartum women were used for dietary quality assessment.Results:The study revealed severe dietary imbalances among postpartum women,characterized by excessive consumption of cereals,eggs,and meats,while their intake of vegetables,fruits,and dairy products was inadequate.According to dietary balance index for postpartum women,66.25%of mothers showed varying degrees of excessive intake.45.31%of mothers experienced varying levels of insufficient intake,with only 19.86%of participants having a relatively balanced diet.Occupational differences were observed,with women in the commercial employment group showing higher levels of excessive food intake.The analysis of influencing factors showed that family monthly income,maternity leave,and postpartum care significantly affected the dietary quality.Conclusions:Postpartum women in Beijing experience widespread dietary imbalances,with both excesses and deficiencies.Occupational context and related factors significantly shape diet quality.These findings highlight the need for targeted nutritional interventions tailored to the specific challenges of different occupational groups.展开更多
The current artificial bone is unable to accurately replicate the inhomogeneity and anisotropy of human cancellous bone.To address this issue,we proposed a personalized approach based on clinical CT images to design m...The current artificial bone is unable to accurately replicate the inhomogeneity and anisotropy of human cancellous bone.To address this issue,we proposed a personalized approach based on clinical CT images to design mechanical equivalent porous structures for artificial femoral heads.Firstly,supported by Micro and clinical CT scans of 21 bone specimens,the anisotropic mechanical parameters of human cancellous bone in the femoral head were characterized using clinical CT values(Hounsfield unit).After that,the equivalent porous structure of cancellous bone was designed based on the gyroid surface,the influence of its degree of anisotropy and volume fraction on the macroscopic mechanical parameters was investigated by finite element analysis.Furthermore,a mapping relationship between CT values and the porous structure was established by jointly solving the mechanical parameters of the porous structure and human cancellous bone,allowing the design of personalized gradient porous structures based on clinical CT images.Finally,to verify the mechanical equivalence,implant press-in tests were conducted on 3D-printed artificial femoral heads and human femoral heads,the influence of the porous structure’s cell size in bone-implant interaction problems was also explored.Results showed that the minimum deviations of press-in stiffness(<15%)and peak load(<5%)both occurred when the cell size was 20%to 30%of the implant diameter.In conclusion,the designed porous structure can replicate the human cancellous bone-implant interaction at a high level,indicating its effectiveness in optimizing the mechanical performance of 3D-printed artificial femoral head.展开更多
The equivalent source(ES)method in the spherical coordinate system has been widely applied to processing,reduction,field modeling,and geophysical and geological interpretation of satellite magnetic anomaly data.Howeve...The equivalent source(ES)method in the spherical coordinate system has been widely applied to processing,reduction,field modeling,and geophysical and geological interpretation of satellite magnetic anomaly data.However,the inversion for the ES model suffers from nonuniqueness and instability,which remain unresolved.To mitigate these issues,we introduce both the minimum and flattest models into the model objective function as an alternative regularization approach in the spherical ES method.We first present the methods,then analyze the accuracy of forward calculation and test the proposed ES method in this study by using synthetic data.The experimental results from simulation data indicate that our proposed regularization effectively suppresses the Backus effect and mitigates inversion instability in the low-latitude region.Finally,we apply the proposed method to magnetic anomaly data from China Seismo-Electromagnetic Satellite-1(CSES-1)and Macao Science Satellite-1(MSS-1)magnetic measurements over Africa by constructing an ES model of the large-scale lithospheric magnetic field.Compared with existing global lithospheric magnetic field models,our ES model demonstrates good consistency at high altitudes and predicts more stable fields at low altitudes.Furthermore,we derive the reduction to the pole(RTP)magnetic anomaly fields and the apparent susceptibility contrast distribution based on the ES model.The latter correlates well with the regional tectonic framework in Africa and surroundings.展开更多
Background:The bibliometrics of acupuncture are growing rapidly.However,the absence of reporting guidelines may lead to significant duplication and waste,thereby undermining the research’s value.To address this,a kno...Background:The bibliometrics of acupuncture are growing rapidly.However,the absence of reporting guidelines may lead to significant duplication and waste,thereby undermining the research’s value.To address this,a knowledge mapping was generated based on published studies to investigate the characteristics of bibliometric studies on acupuncture and the extent of duplicate publications,with the overarching goal of providing a comprehensive overview of the knowledge structure in this field.Methods:This cross-sectional study used three databases(PubMed,Web of Science,and Scopus)to identify relevant studies up to May 1,2024.In addition,the reference lists were retrieved as a supplement.To track research trends,we employed Microsoft Excel and R software to extract,code,and analyze information.Study selection,data extraction,and validation were performed independently by at least two reviewers.The reporting quality of included studies was assessed using the Preliminary guideline for reporting bibliometric reviews of the biomedical literature(BIBLIO).Results:Among the 6,221 bibliometric reviews examined,113 relevant publications were identified,80 focusing on various diseases/conditions.The annual number of publications has gradually increased,with the output in the past four years being 3.52 times higher than that before 2020.China(106)and Chengdu University of Traditional Chinese Medicine(16)have the highest number of publications.The most prolific author is Fan-Rong Liang,with six articles.The first bibliometric study,by Hai-Yan Li,was published in 2010.Journal of Pain Research,with 36 articles,holds the most publications.The top three diseases:diseases of the nervous system;symptoms,signs,or clinical findings not elsewhere classified;and mental,behavioral,or neurodevelopmental disorders.There may be potential duplication in research on 13 diseases/conditions,notably stroke,migraine,pain/analgesia,cancer pain,shoulder pain,facial paralysis/bell’s palsy,chronic pain,and cognitive impairment.In BIBLIO,the most frequently missing items are issues/topics(item 2),quality assessment(item 11),and descriptive findings(item 13).Conclusion:This study demonstrates that acupuncture bibliometrics is actively utilized to identify dominant diseases/conditions,aiding scholars in understand the knowledge structure and main topics.Although the number of related studies is increasing,with an average of 25 studies annually,overlap in some areas highlights the need for adherence to reporting guidelines and careful topic selection to ensure truly valuable insights and knowledge contributions.The adherence to BIBLIO’s 20 proposed items across analyzed articles,highlighting important in reporting practices.展开更多
Objectives:This study aimed to classify young breast cancer patients into distinct ambivalence over emotional expression and to explore the factors influencingthe level of ambivalence over emotional expression.Methods...Objectives:This study aimed to classify young breast cancer patients into distinct ambivalence over emotional expression and to explore the factors influencingthe level of ambivalence over emotional expression.Methods:A total of 217 young breast cancer patients were enrolled from a tertiary Grade A oncology hospital in Tianjin,China,using the convenience sampling method.All participants completed the general questionnaire,Ambivalence over Emotion Expression Questionnaire(AEQ),and Family Adapt-Ability and Cohesion Evaluation Scales-Chinese Version(FACES-CV).We employed exploratory latent profileanalysis for ambivalence over emotional expression profilingand logistic regression analysis to identify the influentialfactors Results:The results of the latent profileanalysis supported the models of four latent profiles,which were definedas“low conflict-lowexpression reflection”(19.2%),“high conflict-high inhibition expression”(43.9%),“moderate conflict-highregret expression”(18.1%),and“moderate conflict-desire understand”(18.8%).Logistic regression revealed that family cohesion,marital status,residence,per capita monthly income,and cancer stage were the influencingfactors of ambivalence over emotional expression in young breast cancer patients(P<0.05)Conclusions:Levels of ambivalence over emotional expression ameast cancer patients with breast cancer were highly heterogeneous.Medical staff should provide psychological counseling and health education tailored to the unique characteristics of emotional expression ambivalence in different patient groups to promote healthy emotional expression among patients.展开更多
Objective:This study aimed to examine the association between parent-child relationships and physically aggressive behavior among adolescents.Methods:This is a cross-sectional study that uses secondary data from the 2...Objective:This study aimed to examine the association between parent-child relationships and physically aggressive behavior among adolescents.Methods:This is a cross-sectional study that uses secondary data from the 2015 Indonesia Global School-Based Health Survey(IGSHS).Health surveys were conducted in 75 schools representing three regions(Sumatra,Java-Bali;Outer Sumatra;and Java-Bali)in 26 provinces and 68 districts/cities in Indonesia(N=10,139 students).Students who participated were aged 12-19 years,were enrolled in public schools in the junior and high school levels.Results:It has been seen that for most middle-aged adolescents(58.7%),their parents(25%-29%)pay less attention to academic assignments(homework),problems,and use of free time.The most significant factors that influence adolescents to commit violence are smoking and consuming alcohol.Adolescents who smoke are twice as likely to commit physical violence compared with adolescents who do not smoke(OR=2.005;95%CI=1.7062-2.396).Meanwhile,adolescents who consume alcohol are 1.8 times more likely to commit physical violence compared with adolescents who do not consume alcohol(OR=1.807;95%CI=1.421-2.298).Conclusions:Through educational activities and consultations,this study’s findings are valuable for establishing parenting programs among those concerned about their children’s aggressive behavior.Meanwhile,counseling programs can be started in schools by conducting self-detection of negative adolescent behavior,such as screening for smoking,alcohol consumption,sleep issues,and attempted suicide.展开更多
The penetration of ogival-nosed projectiles into ship plates represents a complex impact dynamics issue essential for analyzing structural failuremechanisms.Although stiffenedplates are vital in ship construction,fews...The penetration of ogival-nosed projectiles into ship plates represents a complex impact dynamics issue essential for analyzing structural failuremechanisms.Although stiffenedplates are vital in ship construction,fewstudies have addressed the issue of model equivalence under penetration loading.This study employs numerical simulation to validate an experiment with an ogival-nosed projectile penetrating a Q345 steel plate.Four equivalent stiffened plate methods are proposed based on the area,flexural modulus,moment of inertia,and thickness.The results indicate that thickness equivalence(DM4)is unsuitable for penetration-loaded stiffened plates,except under low-speed,nonpenetrating through impacts,and yields less accuracy than DM1/DM3.DM1,DM2,and DM3 each perform optimally with specific velocity ranges:DM1 at very low(critical)and high velocities,DM3 at low velocities,and DM2 at high speeds.Furthermore,in penetration scenarios,T-shaped stiffeners can be replacedwith rectangular ones,as both exhibit similar failure behaviors and deflection trends,simplifying the design while preserving key structural characteristics.These findings provide valuable insights into the design of protective ship structures.展开更多
The high cost and low efficiency of full-scale vehicle experiments and numerical simulations limit the efficient development of armored vehicle occupant protection systems.The floor-occupant-seat local simulation mode...The high cost and low efficiency of full-scale vehicle experiments and numerical simulations limit the efficient development of armored vehicle occupant protection systems.The floor-occupant-seat local simulation model provides an alternative solution for quickly evaluating the performance of occupant protection systems.However,the error and rationality of the loading of the thin-walled floor in the local model cannot be ignored.This study proposed an equivalent loading method for the local model,which includes two parts:the dimensionality reduction method for acceleration matrix and the joint optimization framework for equivalent node coordinates.In the dimensionality reduction method,the dimension of the acceleration matrix was reduced based on the improved kernel principal component analysis(KPCA),and a dynamic variable bandwidth was introduced to address the limitation of failing to effectively measure the similarity between acceleration data in conventional KPCA.In addition,a least squares problem with forced displacement constraints was constructed to solve the correction matrix,thereby achieving the scale restoration process of the principal component acceleration matrix.The joint optimization framework for coordinates consists of the error assessment of response time histories(EARTH)and Bayesian optimization.In this framework,the local loading error of the equivalent acceleration matrix is taken as the Bayesian optimization objective,which is quantified and scored by EARTH.The expected improvement acquisition function was used to select the new set of the equivalent acceleration node coordinates for the self-updating optimization of the observation dataset and Gaussian process surrogate model.We reduced the dimension of the acceleration matrix from 2256 to 7,while retaining 91%of the information features.The comprehensive error score of occupant's lower limb response in the local model increased from 58.5%to 80.4%.The proposed equivalent loading method provides a solution for the rapid and reliable development of occupant protection systems.展开更多
One of the core works of analyzing Electrochemical Impedance Spectroscopy(EIS)data is to select an appropriate equivalent circuit model to quantify the parameters of the electrochemical reaction process.However,this p...One of the core works of analyzing Electrochemical Impedance Spectroscopy(EIS)data is to select an appropriate equivalent circuit model to quantify the parameters of the electrochemical reaction process.However,this process often relies on human experience and judgment,which will introduce subjectivity and error.In this paper,an intelligent approach is proposed for matching EIS data to their equivalent circuits based on the Random Forest algorithm.It can automatically select the most suitable equivalent circuit model based on the characteristics and patterns of EIS data.Addressing the typical scenario of metal corrosion,an atmospheric corrosion EIS dataset of low-carbon steel is constructed in this paper,which includes five different corrosion scenarios.This dataset was used to validate and evaluate the pro-posed method in this paper.The contributions of this paper can be summarized in three aspects:(1)This paper proposes a method for selecting equivalent circuit models for EIS data based on the Random Forest algorithm.(2)Using authentic EIS data collected from metal atmospheric corrosion,the paper es-tablishes a dataset encompassing five categories of metal corrosion scenarios.(3)The superiority of the proposed method is validated through the utilization of the established authentic EIS dataset.The ex-periment results demonstrate that,in terms of equivalent circuit matching,this method surpasses other machine learning algorithms in both precision and robustness.Furthermore,it shows strong applicability in the analysis of EIS data.展开更多
Objective:To study the relationship between qi stagnation constitution and suboptimal health status(SHS)or lifestyle.Methods:From 2012 to 2013,we conducted a cross-sectional survey of 24159 Chinese individuals aged 12...Objective:To study the relationship between qi stagnation constitution and suboptimal health status(SHS)or lifestyle.Methods:From 2012 to 2013,we conducted a cross-sectional survey of 24159 Chinese individuals aged 12-80 years.The qi stagnation constitution was assessed using the Constitution in Chinese Medicine Questionnaire.Health status was evaluated through medical records and the Subhealth Measurement Scale V1.0(SHMS V1.0).Health-promoting lifestyles were measured using the Health-Promoting Lifestyle Profile Ⅱ(HPLP-Ⅱ).Results:Of the 24159 participants,16.1%and 15.2%were classified as“always”and“sometimes”having the qi stagnation constitution,respectively.Those classified as“rarely”having the qi stagnation constitution scored higher on both the HPLP-Ⅱ and SHMS V1.0.The participants classified as“always”having the qi stagnation constitution showed a significant association with SHS or disease compared to other imbalanced constitutions.Those in the“always”category were approximately 21 times more likely to be classified as having SHS(odds ratio[OR]:21.17,95%confidence interval[CI]:15.74-28.45),whereas those in the“sometimes”category were approximately six times more likely(OR:5.89,95%CI:5.04-6.90).Accordingly,the qi stagnation constitution score was significantly associated with the diagnosis of SHS,with an area under the curve of 0.77(P<.001).A score of 18.75 yielded the highest Youden Index(0.407),with a sensitivity of 60.5%and a specificity of 80.3%.Significant associations were observed between health-promoting lifestyles and qi stagnation constitution severity in an ordinal regression analysis(P<.001).Protective factors included stress management(OR:1.59),self-actualization(OR:1.57),and exercise(OR:1.36).In contrast,poorer interpersonal relationships(OR:0.79),greater health responsibilities(OR:0.86),and poorer nutrition(OR:0.91)were associated with increased severity.Conclusion:Modulating the qi stagnation constitution through lifestyle interventions may help prevent the progression of SHS to disease,which aligns with core preventive principles in traditional Chinese medicine.展开更多
The scroll expander,as the core component of the micro-compressed air energy storage and power generation system,directly affects the output efficiency of the system.Meanwhile,the scroll profile plays a central role i...The scroll expander,as the core component of the micro-compressed air energy storage and power generation system,directly affects the output efficiency of the system.Meanwhile,the scroll profile plays a central role in determining the output performance of the scroll expander.In this study,in order to investigate the output characteristics of a variable cross-section scroll expander,numerical simulation and experimental studies were con-ducted by using Computational Fluid Dynamics(CFD)methods and dynamic mesh techniques.The impact of critical parameters on the output performance of the scroll expander was analyzed through the utilization of the control variable method.It is found that increasing the inlet pressure and temperature within a certain range can improve the output power of the scroll expander.However,the increase in temperature and meshing clearance leads to a decline in the overall output performance of the scroll expander,leading to a decrease in volumetric efficiency by 8.43%and 12.79%,respectively.The experiments demonstrate that under equal inlet pressure conditions,increasing the inlet temperature elevates both the rotational speed and torque output of the scroll expander.Specifically,compared to operating at normal temperatures,the output torque increases by 21.8%under high-temperature conditions.However,the rate of speed and torque variation decreases as a consequence of enlarged meshing clearance,resulting in increased internal leakage and reduction in isentropic efficiency.展开更多
Maximize the resource utilization efficiency and guarantee the quality of service(QoS)of users by selecting the network are the key issues for heterogeneous network operators,but the resources occupied by users in dif...Maximize the resource utilization efficiency and guarantee the quality of service(QoS)of users by selecting the network are the key issues for heterogeneous network operators,but the resources occupied by users in different networks cannot be compared directly.This paper proposes a network selection algorithm for heterogeneous network.Firstly,the concept of equivalent bandwidth is proposed,through which the actual resources occupied by users with certain QoS requirements in different networks can be compared directly.Then the concept of network applicability is defined to express the abilities of networks to support different services.The proposed network selection algorithm first evaluates whether the network has enough equivalent bandwidth required by the user and then prioritizes network with poor applicability to avoid the situation that there are still residual resources in entire network,but advanced services can not be admitted.The simulation results show that the proposed algorithm obtained better performance than the baselines in terms of reducing call blocking probability and improving network resource utilization efficiency.展开更多
To address the issue that traditional finite element methods cannot fully consider the semi-infinite earth strata and have lower solution accuracy,a new equivalent force model for induced deformation during oil and ga...To address the issue that traditional finite element methods cannot fully consider the semi-infinite earth strata and have lower solution accuracy,a new equivalent force model for induced deformation during oil and gas reservoir development is derived from the perspective of semi-infinite strata.A brand-new volume boundary element numerical method solution has been developed and verified and tested.The influences of internal flow and flow boundary of the reservoir on strata deformation are equivalent to the impacts on strata deformation when external forces act at the interior and boundary of the reservoir,respectively.Calculation methods for the flow equivalent force and boundary equivalent force are provided.The deformation solution at any point in the strata can be obtained through the convolution of flow equivalent forces,boundary equivalent forces and Green’s functions.After discretization,the deformation solution at any point in the strata can be obtained by multiplying the grid boundary equivalent forces,grid flow equivalent forces with their corresponding grid boundary sources and grid volume sources respectively,and then summing them up.This numerical method is termed the Volumetric Boundary Element Method(VBEM).Compared with traditional commercial simulators,VBEM fully considers the effects of reservoir flow boundaries,pore pressure gradient fields within the reservoir,and fluid mass changes within pores on formation deformation.It eliminates the need for meshing outside the reservoir,achieves significantly improved solution accuracy,and provides a new technical framework for simulating deformation induced by reservoir development.展开更多
OBJECTIVE:To investigate the difference in gut microbiota between population with damp-heat constitution(DHC)and balanced constitution(BC).METHODS:A multi-centered cross-sectional casecontrol study was conducted,which...OBJECTIVE:To investigate the difference in gut microbiota between population with damp-heat constitution(DHC)and balanced constitution(BC).METHODS:A multi-centered cross-sectional casecontrol study was conducted,which included 249 participants with damp-heat constitution or balanced constitution.Baseline information of participants was collected,and stool samples were collected for gut microbiota analysis.Principal coordinate analysis,linear discriminant analysis effect size analysis,receiver operating characteristic,random forest model,and phylogenetic investigation of communities by reconstruction of unobserved states methods were used to reveal the relationship between gut microbiota and the damp-heat constitution.RESULTS:Compared to those in the BC group,the richness and diversity of the microbiota,specifically those of several short-chain fatty acid producing genera such as Barnesiella,Coprobacter,and Butyricimonas,were significantly decreased in the DHC group.Regarding biological functions,flavonoid biosynthesis,propanoate metabolism,and nucleotide sugar metabolism were suppressed,while arachidonic acid metabolism and glutathione metabolism were enriched in the DHC group.Finally,a classifier based on the microbiota was constructed to discriminate between the DHC and BC populations.CONCLUSION:The gut microbiota of the DHC population exhibits significantly reduced diversity and is closely related to inflammation,metabolic disorders,and liver steatosis,which is consistent with clinical observations,thus serving as a potential diagnostic tool for traditional Chinese medicine constitution discrimination.展开更多
To investigate the effects of the maximum principal stress direction(θ)and cross-section shape on the failure characteristics of sandstone,true-triaxial compression experiments were conducted using cubic samples with...To investigate the effects of the maximum principal stress direction(θ)and cross-section shape on the failure characteristics of sandstone,true-triaxial compression experiments were conducted using cubic samples with rectangular,circular,and D-shaped holes.Asθincreases from 0°to 60°in the rectangular hole,the left failure location shifts from the left corner to the left sidewall,the left corner,and then the floor,while the right failure location shifts from the right corner to the right sidewall,right roof corner,and then the roof.Furthermore,the initial failure vertical stress first decreases and then increases.In comparison,the failure severity in the rectangular hole decreases for variousθvalues as 30°>45°>60°>0°.With increasingθ,the fractal dimension(D)of rock slices first increases and then decreases.For the rectangular and D-shaped holes,whenθ=0°,30°,and 90°,D for the rectangular hole is less than that of the D-shaped hole.Whenθ=45°and 60°,D for the rectangular hole is greater than that of the D-shaped hole.Theoretical analysis indicates that the stress concentration at the rectangular and D-shaped corners is greater than the other areas.The failure location rotates with the rotation ofθ,and the failure occurs on the side with a high concentration of compressive stress,while the side with the tensile and compressive stresses remains relatively stable.Therefore,the fundamental reason for the rotation of failure location is the rotation of stress concentration,and the external influencing factor is the rotation ofθ.展开更多
The high-speed winding spindle employs a flexible support system incorporating rubber O-rings.By precisely configuring the structural parameters and the number of the O-rings,the spindle can stably surpass its critica...The high-speed winding spindle employs a flexible support system incorporating rubber O-rings.By precisely configuring the structural parameters and the number of the O-rings,the spindle can stably surpass its critical speed points and maintain operational stability across the entire working speed range.However,the support stiffness and damping of rubber O-rings exhibit significant nonlinear frequency dependence.Conventional experimental methods for deriving equivalent stiffness and damping,based on the principle of the forced non-resonance method,require fabricating custom setups for each O-ring specification and conducting vibration tests at varying frequencies,resulting in low efficiency and high costs.This study proposes a hybrid simulation-experimental method for dynamic parameter identification.Firstly,the frequency-dependent dynamic parameters of a specific O-ring support system are experimentally obtained.Subsequently,a corresponding parametric finite element model is established to simulate and solve the equivalent elastic modulus and equivalent stiffness-damping coefficient of this O-ring support system.Ultimately,after iterative simulation,the simulated and experimental results achieve a 99.7%agreement.The parametric finite element model developed herein can directly simulate and inversely estimate frequency-dependent dynamic parameters for O-rings of different specifications but identical elastic modulus.展开更多
This study introduces a novel method for reconstructing the 3D model of aluminum foam using cross-sectional sequence images.Combining precision milling and image acquisition,high-qual-ity cross-sectional images are ob...This study introduces a novel method for reconstructing the 3D model of aluminum foam using cross-sectional sequence images.Combining precision milling and image acquisition,high-qual-ity cross-sectional images are obtained.Pore structures are segmented by the U-shaped network(U-Net)neural network integrated with the Canny edge detection operator,ensuring accurate pore delineation and edge extraction.The trained U-Net achieves 98.55%accuracy.The 2D data are superimposed and processed into 3D point clouds,enabling reconstruction of the pore structure and aluminum skeleton.Analysis of pore 01 shows the cross-sectional area initially increases,and then decreases with milling depth,with a uniform point distribution of 40 per layer.The reconstructed model exhibits a porosity of 77.5%,with section overlap rates between the 2D pore segmentation and the reconstructed model exceeding 96%,confirming high fidelity.Equivalent sphere diameters decrease with size,averaging 1.95 mm.Compression simulations reveal that the stress-strain curve of the 3D reconstruction model of aluminum foam exhibits fluctuations,and the stresses in the reconstruction model concentrate on thin cell walls,leading to localized deformations.This method accurately restores the aluminum foam’s complex internal structure,improving reconstruction preci-sion and simulation reliability.The approach offers a cost-efficient,high-precision technique for optimizing material performance in engineering applications.展开更多
With the continuous expansion of the power system scale and the increasing complexity of operational mode,the interaction between transmission and distribution systems is becoming more and more significant,placing hig...With the continuous expansion of the power system scale and the increasing complexity of operational mode,the interaction between transmission and distribution systems is becoming more and more significant,placing higher requirements on the accuracy and efficiency of the power system state estimation to address the challenge of balancing computational efficiency and estimation accuracy in traditional coupled transmission and distribution state estimation methods,this paper proposes a collaborative state estimation method based on distribution systems state clustering and load model parameter identification.To resolve the scalability issue of coupled transmission and distribution power systems,clustering is first carried out based on the distribution system states.As the data and models of the transmission system and distribution systems are not shared.For the transmission system,equating the power transmitted from the transmission system to the distribution system is the same as equating the distribution system.Further,the power transmitted from the transmission system to different types of distribution systems is equivalent to different polynomial equivalent load models.Then,a parameter identification method is proposed to obtain the parameters of the equivalent load model.Finally,a transmission and distribution collaborative state estimation model is constructed based on the equivalent load model.The results of the numerical analysis show that compared with the traditional master-slave splitting method,the proposed method significantly enhances computational efficiency while maintaining high estimation accuracy.展开更多
文摘Objective The relationship between non-high-density lipoprotein(NHDL)cholesterol to high-density lipoprotein cholesterol(HDL-C)ratio(NHHR)and stoke remains unknown.This study aimed to evaluate the association between the adult NHHR and stroke occurrence in the United States of America(USA).Methods To clarify the relationship between the NHHR and stroke risk,this study used a multivariable logistic regression model and a restricted cubic spline(RCS)model to investigate the association between the NHHR and stroke,and data from the National Health and Nutrition Examination Survey(NHANES)from 2005 to 2018.Subgroup and sensitivity analyses were conducted to test the robustness of the results.Results This study included 29,928 adult participants,of which 1,165 participants had a history of stroke.Logistic regression analysis of variables demonstrated a positive association between NHHR and stroke(OR 1.24,95%CI:1.03-1.50,P=0.026).Compared with the lowest reference group of NHHR,participants in the second,third,and fourth quartile had a significantly increased risk of stroke after full adjustments(OR:1.35,95%CI:1.08-1.69)(OR:1.83,95%CI:1.42-2.36)(OR:2.04,95%CI:1.50-2.79).In the total population,a nonlinear dose-response relationship was observed between the NHHR and stroke risk(P non-linearity=0.002).This association remained significant in several subgroup analyses.Further investigation of the NHHR may enhance our understanding of stroke prevention and treatment.Conclusion Our findings suggest a positive correlation between the NHHR and an increased prevalence of stroke,potentially serving as a novel predictive factor for stroke.Timely intervention and management of the NHHR may effectively mitigate stroke occurrence.Prospective studies are required to validate this association and further explore the underlying biological mechanisms.
基金financially supported by Guangdong Province Basic and Applied Basic Research Fund Project(Grant No.2022B1515250009)Liaoning Provincial Natural Science Foundation-Doctoral Research Start-up Fund Project(Grant No.2024-BSBA-05)+1 种基金Major Science and Technology Innovation Project in Shandong Province(Grant No.2024CXGC010803)the National Natural Science Foundation of China(Grant Nos.52271269 and 12302147).
文摘The umbilical,a key component in offshore energy extraction,plays a vital role in ensuring the stable operation of the entire production system.The extensive variety of cross-sectional components creates highly complex layout combinations.Furthermore,due to constraints in component quantity and geometry within the cross-sectional layout,filler bodies must be incorporated to maintain cross-section performance.Conventional design approaches based on manual experience suffer from inefficiency,high variability,and difficulties in quantification.This paper presents a multi-level automatic filling optimization design method for umbilical cross-sectional layouts to address these limitations.Initially,the research establishes a multi-objective optimization model that considers compactness,balance,and wear resistance of the cross-section,employing an enhanced genetic algorithm to achieve a near-optimal layout.Subsequently,the study implements an image processing-based vacancy detection technique to accurately identify cross-sectional gaps.To manage the variability and diversity of these vacant regions,the research introduces a multi-level filling method that strategically selects and places filler bodies of varying dimensions,overcoming the constraints of uniform-size fillers.Additionally,the method incorporates a hierarchical strategy that subdivides the complex cross-section into multiple layers,enabling layer-by-layer optimization and filling.This approach reduces manufac-turing equipment requirements while ensuring practical production process feasibility.The methodology is validated through a specific umbilical case study.The results demonstrate improvements in compactness,balance,and wear resistance compared with the initial cross-section,offering novel insights and valuable references for filler design in umbilical cross-sections.
基金supported by an Innovation Fund for Medical Sciences of the Chinese Academy of Medical Sciences (Grant No.2019-I2M-2-007).
文摘Objective:Postpartum nutrition plays a critical role in maternal recovery and long-term health.However,the nutritional status of working mothers in the postpartum period remains understudied.This study aimed to assess the dietary quality of postpartum women in urban Beijing,identify occupational-related factors influencing their diet,and explore potential interventions to improve maternal nutrition during the postpartum period.Methods:In this cross-sectional analysis,554 women one year after delivery were recruited from ten community health centers.Sociodemographic,occupational and postpartum care variables were collected via questionnaire.Dietary intake over the preceding year was assessed using a food frequency questionnaire.The modified dietary balance index for postpartum women were used for dietary quality assessment.Results:The study revealed severe dietary imbalances among postpartum women,characterized by excessive consumption of cereals,eggs,and meats,while their intake of vegetables,fruits,and dairy products was inadequate.According to dietary balance index for postpartum women,66.25%of mothers showed varying degrees of excessive intake.45.31%of mothers experienced varying levels of insufficient intake,with only 19.86%of participants having a relatively balanced diet.Occupational differences were observed,with women in the commercial employment group showing higher levels of excessive food intake.The analysis of influencing factors showed that family monthly income,maternity leave,and postpartum care significantly affected the dietary quality.Conclusions:Postpartum women in Beijing experience widespread dietary imbalances,with both excesses and deficiencies.Occupational context and related factors significantly shape diet quality.These findings highlight the need for targeted nutritional interventions tailored to the specific challenges of different occupational groups.
基金supported by the National Key R&D Program of China(Grant No.2021YFC2501700).
文摘The current artificial bone is unable to accurately replicate the inhomogeneity and anisotropy of human cancellous bone.To address this issue,we proposed a personalized approach based on clinical CT images to design mechanical equivalent porous structures for artificial femoral heads.Firstly,supported by Micro and clinical CT scans of 21 bone specimens,the anisotropic mechanical parameters of human cancellous bone in the femoral head were characterized using clinical CT values(Hounsfield unit).After that,the equivalent porous structure of cancellous bone was designed based on the gyroid surface,the influence of its degree of anisotropy and volume fraction on the macroscopic mechanical parameters was investigated by finite element analysis.Furthermore,a mapping relationship between CT values and the porous structure was established by jointly solving the mechanical parameters of the porous structure and human cancellous bone,allowing the design of personalized gradient porous structures based on clinical CT images.Finally,to verify the mechanical equivalence,implant press-in tests were conducted on 3D-printed artificial femoral heads and human femoral heads,the influence of the porous structure’s cell size in bone-implant interaction problems was also explored.Results showed that the minimum deviations of press-in stiffness(<15%)and peak load(<5%)both occurred when the cell size was 20%to 30%of the implant diameter.In conclusion,the designed porous structure can replicate the human cancellous bone-implant interaction at a high level,indicating its effectiveness in optimizing the mechanical performance of 3D-printed artificial femoral head.
基金supported by the National Natural Science Foundation of China(Grant Nos.42250103 and 42174090)the Opening Fund of Key Laboratory of Geological Survey and Evaluation of Ministry of Education(Grant No.GLAB2023ZR02)the MOST Special Fund from the State Key Laboratory of Geological Processes and Mineral Resources(Grant No.MSFGPMR2022-4).
文摘The equivalent source(ES)method in the spherical coordinate system has been widely applied to processing,reduction,field modeling,and geophysical and geological interpretation of satellite magnetic anomaly data.However,the inversion for the ES model suffers from nonuniqueness and instability,which remain unresolved.To mitigate these issues,we introduce both the minimum and flattest models into the model objective function as an alternative regularization approach in the spherical ES method.We first present the methods,then analyze the accuracy of forward calculation and test the proposed ES method in this study by using synthetic data.The experimental results from simulation data indicate that our proposed regularization effectively suppresses the Backus effect and mitigates inversion instability in the low-latitude region.Finally,we apply the proposed method to magnetic anomaly data from China Seismo-Electromagnetic Satellite-1(CSES-1)and Macao Science Satellite-1(MSS-1)magnetic measurements over Africa by constructing an ES model of the large-scale lithospheric magnetic field.Compared with existing global lithospheric magnetic field models,our ES model demonstrates good consistency at high altitudes and predicts more stable fields at low altitudes.Furthermore,we derive the reduction to the pole(RTP)magnetic anomaly fields and the apparent susceptibility contrast distribution based on the ES model.The latter correlates well with the regional tectonic framework in Africa and surroundings.
基金supported by the Innovation Team and Talents Cultivation Program of National Administration of Traditional Chinese Medicine(ZYYCXTD-C-202006)the High-level traditional Chinese medicine key subject construction project of National Administration of Traditional Chinese Medicine-Evidence-based Traditional Chinese Medicine(ZYYZDXK-2023249).
文摘Background:The bibliometrics of acupuncture are growing rapidly.However,the absence of reporting guidelines may lead to significant duplication and waste,thereby undermining the research’s value.To address this,a knowledge mapping was generated based on published studies to investigate the characteristics of bibliometric studies on acupuncture and the extent of duplicate publications,with the overarching goal of providing a comprehensive overview of the knowledge structure in this field.Methods:This cross-sectional study used three databases(PubMed,Web of Science,and Scopus)to identify relevant studies up to May 1,2024.In addition,the reference lists were retrieved as a supplement.To track research trends,we employed Microsoft Excel and R software to extract,code,and analyze information.Study selection,data extraction,and validation were performed independently by at least two reviewers.The reporting quality of included studies was assessed using the Preliminary guideline for reporting bibliometric reviews of the biomedical literature(BIBLIO).Results:Among the 6,221 bibliometric reviews examined,113 relevant publications were identified,80 focusing on various diseases/conditions.The annual number of publications has gradually increased,with the output in the past four years being 3.52 times higher than that before 2020.China(106)and Chengdu University of Traditional Chinese Medicine(16)have the highest number of publications.The most prolific author is Fan-Rong Liang,with six articles.The first bibliometric study,by Hai-Yan Li,was published in 2010.Journal of Pain Research,with 36 articles,holds the most publications.The top three diseases:diseases of the nervous system;symptoms,signs,or clinical findings not elsewhere classified;and mental,behavioral,or neurodevelopmental disorders.There may be potential duplication in research on 13 diseases/conditions,notably stroke,migraine,pain/analgesia,cancer pain,shoulder pain,facial paralysis/bell’s palsy,chronic pain,and cognitive impairment.In BIBLIO,the most frequently missing items are issues/topics(item 2),quality assessment(item 11),and descriptive findings(item 13).Conclusion:This study demonstrates that acupuncture bibliometrics is actively utilized to identify dominant diseases/conditions,aiding scholars in understand the knowledge structure and main topics.Although the number of related studies is increasing,with an average of 25 studies annually,overlap in some areas highlights the need for adherence to reporting guidelines and careful topic selection to ensure truly valuable insights and knowledge contributions.The adherence to BIBLIO’s 20 proposed items across analyzed articles,highlighting important in reporting practices.
基金funded by Tianjin Key Medical Discipline(Specialty)Construction Project,China(Grant No.TJYXZDXK-011A)Tianjin Medical University Cancer Institute&Hospital Nursing Special Fund Project(H2304)。
文摘Objectives:This study aimed to classify young breast cancer patients into distinct ambivalence over emotional expression and to explore the factors influencingthe level of ambivalence over emotional expression.Methods:A total of 217 young breast cancer patients were enrolled from a tertiary Grade A oncology hospital in Tianjin,China,using the convenience sampling method.All participants completed the general questionnaire,Ambivalence over Emotion Expression Questionnaire(AEQ),and Family Adapt-Ability and Cohesion Evaluation Scales-Chinese Version(FACES-CV).We employed exploratory latent profileanalysis for ambivalence over emotional expression profilingand logistic regression analysis to identify the influentialfactors Results:The results of the latent profileanalysis supported the models of four latent profiles,which were definedas“low conflict-lowexpression reflection”(19.2%),“high conflict-high inhibition expression”(43.9%),“moderate conflict-highregret expression”(18.1%),and“moderate conflict-desire understand”(18.8%).Logistic regression revealed that family cohesion,marital status,residence,per capita monthly income,and cancer stage were the influencingfactors of ambivalence over emotional expression in young breast cancer patients(P<0.05)Conclusions:Levels of ambivalence over emotional expression ameast cancer patients with breast cancer were highly heterogeneous.Medical staff should provide psychological counseling and health education tailored to the unique characteristics of emotional expression ambivalence in different patient groups to promote healthy emotional expression among patients.
文摘Objective:This study aimed to examine the association between parent-child relationships and physically aggressive behavior among adolescents.Methods:This is a cross-sectional study that uses secondary data from the 2015 Indonesia Global School-Based Health Survey(IGSHS).Health surveys were conducted in 75 schools representing three regions(Sumatra,Java-Bali;Outer Sumatra;and Java-Bali)in 26 provinces and 68 districts/cities in Indonesia(N=10,139 students).Students who participated were aged 12-19 years,were enrolled in public schools in the junior and high school levels.Results:It has been seen that for most middle-aged adolescents(58.7%),their parents(25%-29%)pay less attention to academic assignments(homework),problems,and use of free time.The most significant factors that influence adolescents to commit violence are smoking and consuming alcohol.Adolescents who smoke are twice as likely to commit physical violence compared with adolescents who do not smoke(OR=2.005;95%CI=1.7062-2.396).Meanwhile,adolescents who consume alcohol are 1.8 times more likely to commit physical violence compared with adolescents who do not consume alcohol(OR=1.807;95%CI=1.421-2.298).Conclusions:Through educational activities and consultations,this study’s findings are valuable for establishing parenting programs among those concerned about their children’s aggressive behavior.Meanwhile,counseling programs can be started in schools by conducting self-detection of negative adolescent behavior,such as screening for smoking,alcohol consumption,sleep issues,and attempted suicide.
基金supported by Natural Science Foundation of Fujian Province(2022I0019)Scientific Research Foundation for Jimei University(ZQ2024041,ZQ2024042).
文摘The penetration of ogival-nosed projectiles into ship plates represents a complex impact dynamics issue essential for analyzing structural failuremechanisms.Although stiffenedplates are vital in ship construction,fewstudies have addressed the issue of model equivalence under penetration loading.This study employs numerical simulation to validate an experiment with an ogival-nosed projectile penetrating a Q345 steel plate.Four equivalent stiffened plate methods are proposed based on the area,flexural modulus,moment of inertia,and thickness.The results indicate that thickness equivalence(DM4)is unsuitable for penetration-loaded stiffened plates,except under low-speed,nonpenetrating through impacts,and yields less accuracy than DM1/DM3.DM1,DM2,and DM3 each perform optimally with specific velocity ranges:DM1 at very low(critical)and high velocities,DM3 at low velocities,and DM2 at high speeds.Furthermore,in penetration scenarios,T-shaped stiffeners can be replacedwith rectangular ones,as both exhibit similar failure behaviors and deflection trends,simplifying the design while preserving key structural characteristics.These findings provide valuable insights into the design of protective ship structures.
基金supported by the National Natural Science Foundation of China(Grant Nos.52272437 and 52272370)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX24_0635)。
文摘The high cost and low efficiency of full-scale vehicle experiments and numerical simulations limit the efficient development of armored vehicle occupant protection systems.The floor-occupant-seat local simulation model provides an alternative solution for quickly evaluating the performance of occupant protection systems.However,the error and rationality of the loading of the thin-walled floor in the local model cannot be ignored.This study proposed an equivalent loading method for the local model,which includes two parts:the dimensionality reduction method for acceleration matrix and the joint optimization framework for equivalent node coordinates.In the dimensionality reduction method,the dimension of the acceleration matrix was reduced based on the improved kernel principal component analysis(KPCA),and a dynamic variable bandwidth was introduced to address the limitation of failing to effectively measure the similarity between acceleration data in conventional KPCA.In addition,a least squares problem with forced displacement constraints was constructed to solve the correction matrix,thereby achieving the scale restoration process of the principal component acceleration matrix.The joint optimization framework for coordinates consists of the error assessment of response time histories(EARTH)and Bayesian optimization.In this framework,the local loading error of the equivalent acceleration matrix is taken as the Bayesian optimization objective,which is quantified and scored by EARTH.The expected improvement acquisition function was used to select the new set of the equivalent acceleration node coordinates for the self-updating optimization of the observation dataset and Gaussian process surrogate model.We reduced the dimension of the acceleration matrix from 2256 to 7,while retaining 91%of the information features.The comprehensive error score of occupant's lower limb response in the local model increased from 58.5%to 80.4%.The proposed equivalent loading method provides a solution for the rapid and reliable development of occupant protection systems.
基金support of the project from the National Key R&D Program of China,Research and Application of Sensing System for Cross-regional Complex Oil&Gas Pipeline Network Safe and Efficiency Operational Status Monitoring(Grant No.2022YFB3207603).
文摘One of the core works of analyzing Electrochemical Impedance Spectroscopy(EIS)data is to select an appropriate equivalent circuit model to quantify the parameters of the electrochemical reaction process.However,this process often relies on human experience and judgment,which will introduce subjectivity and error.In this paper,an intelligent approach is proposed for matching EIS data to their equivalent circuits based on the Random Forest algorithm.It can automatically select the most suitable equivalent circuit model based on the characteristics and patterns of EIS data.Addressing the typical scenario of metal corrosion,an atmospheric corrosion EIS dataset of low-carbon steel is constructed in this paper,which includes five different corrosion scenarios.This dataset was used to validate and evaluate the pro-posed method in this paper.The contributions of this paper can be summarized in three aspects:(1)This paper proposes a method for selecting equivalent circuit models for EIS data based on the Random Forest algorithm.(2)Using authentic EIS data collected from metal atmospheric corrosion,the paper es-tablishes a dataset encompassing five categories of metal corrosion scenarios.(3)The superiority of the proposed method is validated through the utilization of the established authentic EIS dataset.The ex-periment results demonstrate that,in terms of equivalent circuit matching,this method surpasses other machine learning algorithms in both precision and robustness.Furthermore,it shows strong applicability in the analysis of EIS data.
基金supported by the National Natural Science Foundation of China(T2341019)NSFC-Guangdong Joint Fund(U1132001)+9 种基金General Program of the National Natural Science Foundation of China(82174243 and 82204948)Natural Science Foundation of Guangdong Province,China(2023A1515110757)Guangzhou Science and Technology Plan Project(2024B03J1343)Major Scientific and Technological Project of Guangzhou Municipal Health Commission(20252D003)Research Project of Traditional Chinese Medicine Bureau of Guangdong Province(20241208)General project of Beijing Natural Science Foundation(7242227)Fundamental Research Funds for the Central Universities(BZY-JMZY-2022-001 and 2023-JYB-JBZD-009)High-level Key Discipline of the National Administration of Traditional Chinese Medicine-Traditional Chinese Constitutional Medicine(zyyzdxk-2023251)Major Science and Technology Special Projects in Hubei Province(2023BCA005)the Chief Scientist Research Project of Hubei Shizhen Laboratory(HSL2024SX0002).
文摘Objective:To study the relationship between qi stagnation constitution and suboptimal health status(SHS)or lifestyle.Methods:From 2012 to 2013,we conducted a cross-sectional survey of 24159 Chinese individuals aged 12-80 years.The qi stagnation constitution was assessed using the Constitution in Chinese Medicine Questionnaire.Health status was evaluated through medical records and the Subhealth Measurement Scale V1.0(SHMS V1.0).Health-promoting lifestyles were measured using the Health-Promoting Lifestyle Profile Ⅱ(HPLP-Ⅱ).Results:Of the 24159 participants,16.1%and 15.2%were classified as“always”and“sometimes”having the qi stagnation constitution,respectively.Those classified as“rarely”having the qi stagnation constitution scored higher on both the HPLP-Ⅱ and SHMS V1.0.The participants classified as“always”having the qi stagnation constitution showed a significant association with SHS or disease compared to other imbalanced constitutions.Those in the“always”category were approximately 21 times more likely to be classified as having SHS(odds ratio[OR]:21.17,95%confidence interval[CI]:15.74-28.45),whereas those in the“sometimes”category were approximately six times more likely(OR:5.89,95%CI:5.04-6.90).Accordingly,the qi stagnation constitution score was significantly associated with the diagnosis of SHS,with an area under the curve of 0.77(P<.001).A score of 18.75 yielded the highest Youden Index(0.407),with a sensitivity of 60.5%and a specificity of 80.3%.Significant associations were observed between health-promoting lifestyles and qi stagnation constitution severity in an ordinal regression analysis(P<.001).Protective factors included stress management(OR:1.59),self-actualization(OR:1.57),and exercise(OR:1.36).In contrast,poorer interpersonal relationships(OR:0.79),greater health responsibilities(OR:0.86),and poorer nutrition(OR:0.91)were associated with increased severity.Conclusion:Modulating the qi stagnation constitution through lifestyle interventions may help prevent the progression of SHS to disease,which aligns with core preventive principles in traditional Chinese medicine.
基金funded by the National Key Research and Development Program of China(No.2024YFE0208100).
文摘The scroll expander,as the core component of the micro-compressed air energy storage and power generation system,directly affects the output efficiency of the system.Meanwhile,the scroll profile plays a central role in determining the output performance of the scroll expander.In this study,in order to investigate the output characteristics of a variable cross-section scroll expander,numerical simulation and experimental studies were con-ducted by using Computational Fluid Dynamics(CFD)methods and dynamic mesh techniques.The impact of critical parameters on the output performance of the scroll expander was analyzed through the utilization of the control variable method.It is found that increasing the inlet pressure and temperature within a certain range can improve the output power of the scroll expander.However,the increase in temperature and meshing clearance leads to a decline in the overall output performance of the scroll expander,leading to a decrease in volumetric efficiency by 8.43%and 12.79%,respectively.The experiments demonstrate that under equal inlet pressure conditions,increasing the inlet temperature elevates both the rotational speed and torque output of the scroll expander.Specifically,compared to operating at normal temperatures,the output torque increases by 21.8%under high-temperature conditions.However,the rate of speed and torque variation decreases as a consequence of enlarged meshing clearance,resulting in increased internal leakage and reduction in isentropic efficiency.
文摘Maximize the resource utilization efficiency and guarantee the quality of service(QoS)of users by selecting the network are the key issues for heterogeneous network operators,but the resources occupied by users in different networks cannot be compared directly.This paper proposes a network selection algorithm for heterogeneous network.Firstly,the concept of equivalent bandwidth is proposed,through which the actual resources occupied by users with certain QoS requirements in different networks can be compared directly.Then the concept of network applicability is defined to express the abilities of networks to support different services.The proposed network selection algorithm first evaluates whether the network has enough equivalent bandwidth required by the user and then prioritizes network with poor applicability to avoid the situation that there are still residual resources in entire network,but advanced services can not be admitted.The simulation results show that the proposed algorithm obtained better performance than the baselines in terms of reducing call blocking probability and improving network resource utilization efficiency.
基金Supported by the China National Natural Science Foundation Project(52274048)Beijing Natural Science Foundation Project(3222037)。
文摘To address the issue that traditional finite element methods cannot fully consider the semi-infinite earth strata and have lower solution accuracy,a new equivalent force model for induced deformation during oil and gas reservoir development is derived from the perspective of semi-infinite strata.A brand-new volume boundary element numerical method solution has been developed and verified and tested.The influences of internal flow and flow boundary of the reservoir on strata deformation are equivalent to the impacts on strata deformation when external forces act at the interior and boundary of the reservoir,respectively.Calculation methods for the flow equivalent force and boundary equivalent force are provided.The deformation solution at any point in the strata can be obtained through the convolution of flow equivalent forces,boundary equivalent forces and Green’s functions.After discretization,the deformation solution at any point in the strata can be obtained by multiplying the grid boundary equivalent forces,grid flow equivalent forces with their corresponding grid boundary sources and grid volume sources respectively,and then summing them up.This numerical method is termed the Volumetric Boundary Element Method(VBEM).Compared with traditional commercial simulators,VBEM fully considers the effects of reservoir flow boundaries,pore pressure gradient fields within the reservoir,and fluid mass changes within pores on formation deformation.It eliminates the need for meshing outside the reservoir,achieves significantly improved solution accuracy,and provides a new technical framework for simulating deformation induced by reservoir development.
基金National Nonprofit Institute Research Grant for the Institute of Basic Theory for Chinese Medicine,China Academy of Chinese Medical Sciences:Mechanism of Regulating Phlegm-Dampness Constitution to Prevent Metabolic Diseases based on Gut Microbiota-host DNA Methylation(No.YZ-202151)。
文摘OBJECTIVE:To investigate the difference in gut microbiota between population with damp-heat constitution(DHC)and balanced constitution(BC).METHODS:A multi-centered cross-sectional casecontrol study was conducted,which included 249 participants with damp-heat constitution or balanced constitution.Baseline information of participants was collected,and stool samples were collected for gut microbiota analysis.Principal coordinate analysis,linear discriminant analysis effect size analysis,receiver operating characteristic,random forest model,and phylogenetic investigation of communities by reconstruction of unobserved states methods were used to reveal the relationship between gut microbiota and the damp-heat constitution.RESULTS:Compared to those in the BC group,the richness and diversity of the microbiota,specifically those of several short-chain fatty acid producing genera such as Barnesiella,Coprobacter,and Butyricimonas,were significantly decreased in the DHC group.Regarding biological functions,flavonoid biosynthesis,propanoate metabolism,and nucleotide sugar metabolism were suppressed,while arachidonic acid metabolism and glutathione metabolism were enriched in the DHC group.Finally,a classifier based on the microbiota was constructed to discriminate between the DHC and BC populations.CONCLUSION:The gut microbiota of the DHC population exhibits significantly reduced diversity and is closely related to inflammation,metabolic disorders,and liver steatosis,which is consistent with clinical observations,thus serving as a potential diagnostic tool for traditional Chinese medicine constitution discrimination.
基金supported by the National Natural Science Foundation of China (Grant Nos.52304227 and 52104133)Scientific and Technological Research Platform for Disaster Prevention and Control of Deep Coal Mining (Anhui University of Science and Technology) (Grant No.DPDCM2208).
文摘To investigate the effects of the maximum principal stress direction(θ)and cross-section shape on the failure characteristics of sandstone,true-triaxial compression experiments were conducted using cubic samples with rectangular,circular,and D-shaped holes.Asθincreases from 0°to 60°in the rectangular hole,the left failure location shifts from the left corner to the left sidewall,the left corner,and then the floor,while the right failure location shifts from the right corner to the right sidewall,right roof corner,and then the roof.Furthermore,the initial failure vertical stress first decreases and then increases.In comparison,the failure severity in the rectangular hole decreases for variousθvalues as 30°>45°>60°>0°.With increasingθ,the fractal dimension(D)of rock slices first increases and then decreases.For the rectangular and D-shaped holes,whenθ=0°,30°,and 90°,D for the rectangular hole is less than that of the D-shaped hole.Whenθ=45°and 60°,D for the rectangular hole is greater than that of the D-shaped hole.Theoretical analysis indicates that the stress concentration at the rectangular and D-shaped corners is greater than the other areas.The failure location rotates with the rotation ofθ,and the failure occurs on the side with a high concentration of compressive stress,while the side with the tensile and compressive stresses remains relatively stable.Therefore,the fundamental reason for the rotation of failure location is the rotation of stress concentration,and the external influencing factor is the rotation ofθ.
基金National Key R&D Program of China(No.2017YFB1304000)Fundamental Research Funds for the Central Universities,China(No.2232023G-05-1)。
文摘The high-speed winding spindle employs a flexible support system incorporating rubber O-rings.By precisely configuring the structural parameters and the number of the O-rings,the spindle can stably surpass its critical speed points and maintain operational stability across the entire working speed range.However,the support stiffness and damping of rubber O-rings exhibit significant nonlinear frequency dependence.Conventional experimental methods for deriving equivalent stiffness and damping,based on the principle of the forced non-resonance method,require fabricating custom setups for each O-ring specification and conducting vibration tests at varying frequencies,resulting in low efficiency and high costs.This study proposes a hybrid simulation-experimental method for dynamic parameter identification.Firstly,the frequency-dependent dynamic parameters of a specific O-ring support system are experimentally obtained.Subsequently,a corresponding parametric finite element model is established to simulate and solve the equivalent elastic modulus and equivalent stiffness-damping coefficient of this O-ring support system.Ultimately,after iterative simulation,the simulated and experimental results achieve a 99.7%agreement.The parametric finite element model developed herein can directly simulate and inversely estimate frequency-dependent dynamic parameters for O-rings of different specifications but identical elastic modulus.
基金supported by the Key Research and DevelopmentPlan in Shanxi Province of China(No.201803D421045)the Natural Science Foundation of Shanxi Province(No.2021-0302-123104)。
文摘This study introduces a novel method for reconstructing the 3D model of aluminum foam using cross-sectional sequence images.Combining precision milling and image acquisition,high-qual-ity cross-sectional images are obtained.Pore structures are segmented by the U-shaped network(U-Net)neural network integrated with the Canny edge detection operator,ensuring accurate pore delineation and edge extraction.The trained U-Net achieves 98.55%accuracy.The 2D data are superimposed and processed into 3D point clouds,enabling reconstruction of the pore structure and aluminum skeleton.Analysis of pore 01 shows the cross-sectional area initially increases,and then decreases with milling depth,with a uniform point distribution of 40 per layer.The reconstructed model exhibits a porosity of 77.5%,with section overlap rates between the 2D pore segmentation and the reconstructed model exceeding 96%,confirming high fidelity.Equivalent sphere diameters decrease with size,averaging 1.95 mm.Compression simulations reveal that the stress-strain curve of the 3D reconstruction model of aluminum foam exhibits fluctuations,and the stresses in the reconstruction model concentrate on thin cell walls,leading to localized deformations.This method accurately restores the aluminum foam’s complex internal structure,improving reconstruction preci-sion and simulation reliability.The approach offers a cost-efficient,high-precision technique for optimizing material performance in engineering applications.
基金State Grid Jiangsu Electric Power Co.,Ltd.Technology Project(J2023121).
文摘With the continuous expansion of the power system scale and the increasing complexity of operational mode,the interaction between transmission and distribution systems is becoming more and more significant,placing higher requirements on the accuracy and efficiency of the power system state estimation to address the challenge of balancing computational efficiency and estimation accuracy in traditional coupled transmission and distribution state estimation methods,this paper proposes a collaborative state estimation method based on distribution systems state clustering and load model parameter identification.To resolve the scalability issue of coupled transmission and distribution power systems,clustering is first carried out based on the distribution system states.As the data and models of the transmission system and distribution systems are not shared.For the transmission system,equating the power transmitted from the transmission system to the distribution system is the same as equating the distribution system.Further,the power transmitted from the transmission system to different types of distribution systems is equivalent to different polynomial equivalent load models.Then,a parameter identification method is proposed to obtain the parameters of the equivalent load model.Finally,a transmission and distribution collaborative state estimation model is constructed based on the equivalent load model.The results of the numerical analysis show that compared with the traditional master-slave splitting method,the proposed method significantly enhances computational efficiency while maintaining high estimation accuracy.
