The rapid prediction of aerodynamic performance is critical in the conceptual and preliminary design of hypersonic vehicles. This study focused on axisymmetric body configurations commonly used in such vehicles and pr...The rapid prediction of aerodynamic performance is critical in the conceptual and preliminary design of hypersonic vehicles. This study focused on axisymmetric body configurations commonly used in such vehicles and proposed a multi-fidelity neural network (MFNN) framework to fuse aerodynamic data of varying quality. A data-driven prediction model was constructed using a pointwise modeling method based on generating lines to input geometric features into the network. The MFNN framework combined low-fidelity and high-fidelity networks, trained on aerodynamic performance data from engineering rapid computation methods and CFD, respectively, using spherically blunted cones as examples. The results showed that the MFNN effectively integrated multi-fidelity data, achieving prediction accuracy close to CFD results in most regions, with errors under 5% in key stagnation areas. The model demonstrated strong generalization capabilities for varying cone dimensions and flight conditions. Furthermore, it significantly reduced dependence on high-fidelity data, enabling efficient aerodynamic performance predictions with limited datasets. This study provides a novel methodology for rapid aerodynamic performance prediction, offering both accuracy and efficiency, and contributes to the design of hypersonic vehicles.展开更多
When an energetic parton traverses the hot QCD medium,it may suffer from multiple scattering and lose its energy.The medium-induced gluon radiation for a massive quark will be suppressed relative to that of a light qu...When an energetic parton traverses the hot QCD medium,it may suffer from multiple scattering and lose its energy.The medium-induced gluon radiation for a massive quark will be suppressed relative to that of a light quark due to the dead-cone effect.The development of new declustering techniques of jet evolution makes a direct study of the dead-cone effect in the QCD medium possible for the first time.In this work,we compute the emission angle distribution of the charm-quark-initiated splittings in D^(0) meson tagged jet and that of the light parton-initiated splittings in an inclusive jet in p+p and Pb+Pb at 5.02 TeV by utilizing the declustering techniques of jet evolution.The heavy quark propagation and induced energy loss in the QCD medium are simulated with the SHELL model based on the Langevin equation.By directly comparing the emission angle distributions of charm-quark-initiated splittings with those of light parton-initiated splittings at the same energy intervals of the initial parton,we provide insights into the fundamental splitting structure in A+A collisions,thereby exploring the possible observation of the dead-cone effect in medium-induced radiation.We further investigate the case of the emission angle distributions normalized to the number of splittings and find the dead-cone effect will broaden the emission angle of the splitting and reduce the possibility for such splitting to occur,leading the massive parton to lose less energy.We also find that the collisional energy loss mechanism has a negligible impact on the medium modification to the emission angle distribution of the charm-quark-initiated splittings for D^(0) meson-tagged jets.展开更多
Currently,the cranes used at sea do not have enough flexibility,efficiency,and safety.Thus,this study proposed a floating multirobot coordinated towing system to meet the demands for offshore towing.Because of the fle...Currently,the cranes used at sea do not have enough flexibility,efficiency,and safety.Thus,this study proposed a floating multirobot coordinated towing system to meet the demands for offshore towing.Because of the flexibility of rope-driven robots,the one-way pulling characteristics of the rope,and the floating characteristics of the base,towing robots are easily overturned.First,the spatial configuration of the towing system was established according to the towing task,and the kinematic model of the towing system was established using the coordinate transformation.Then,the dynamic model of the towing system was established according to the rigid-body dynamics and hydrodynamic theory.Finally,the stability of the towing system was analyzed using the stability cone method.The simulation experiments provide a reference for the practical application of the floating multirobot coordinated towing system,which can improve the stability of towing systems by changing the configuration of the towing robot.展开更多
In this paper,we consider the symmetric cone linear complementarity problem with the Cartesian P0-property and present a regularization smoothing method with a nonmonotone line search to solve this problem.It has been...In this paper,we consider the symmetric cone linear complementarity problem with the Cartesian P0-property and present a regularization smoothing method with a nonmonotone line search to solve this problem.It has been demonstrated that the proposed method exhibits global convergence under the condition that the solution set of the complementarity problem is nonempty.This condition is less stringent than those that have appeared in some existing literature.We also show that the method has locally quadratic convergence under appropriate conditions.Some experimental results are reported to illustrate the efficiency of the proposed method.展开更多
For cone beam computed tomography(CBCT),there has long been a desire to modulate the intensity and distribution of the X-rays to accommodate the patient’s anatomy as the gantry rotates from one projection to another....For cone beam computed tomography(CBCT),there has long been a desire to modulate the intensity and distribution of the X-rays to accommodate the patient’s anatomy as the gantry rotates from one projection to another.This would reduce both image artifacts and radiation dose.However,the current beam modulation setups,such as dynamic bowtie filters,may be too complex for practical use in clinical applications.This study aimed to investigate a simplified dynamic beam filtration strategy for CBCT imaging to reduce image artifacts and radiation dose.In this study,the beam filtration was designed to vary dynamically as the CBCT gantry rotates around the object.Specifically,two distinct components were integrated:the sheet filter part and the bowtie filter part.The dynamic beam filtration setup has two working schemes,one is a combination of dynamic sheet filter and dynamic bowtie filter,denoted as dynamic filterdynamic bowtie(DFDB);the other is a combination of dynamic sheet filter and static bowtie filter,denoted as dynamic filter-static bowtie(DFSB).Numerical imaging experiments were performed for three human body parts:the shoulder,chest,and knee.In addition,the Monte Carlo simulation platform MC-GPU was used to generate the dose distribution maps.Results showed that the proposed DFDB and DFSB beam filtration schemes can significantly reduce the image artifacts and thus improve the CBCT image quality.Depending on the scanned object,the total radiation dose could be reduced by 30%.The proposed simple dynamic beam filtration strategy,especially the DFSB approach,could be beneficial in the future to improve the CBCT image quality with reduced image artifacts and radiation dose.展开更多
The optimization of the waverider is constrained by the reversely designed leading edge and the constant shock angle distribution. This paper proposes a design method called the variable Leading-Edge Cone (vLEC) metho...The optimization of the waverider is constrained by the reversely designed leading edge and the constant shock angle distribution. This paper proposes a design method called the variable Leading-Edge Cone (vLEC) method to address these limitations. In the vLEC method, the waverider is directly designed from the preassigned leading edge and the variable shock angle distribution based on the Leading-Edge Cone (LEC) concept. Since the vLEC method is an approximate method, two test waveriders are designed and evaluated using numerical simulations to validate the shock design accuracy and the effectiveness of the vLEC method. The results show that the shocks of the test waveriders coincide well with the preassigned positions. Furthermore, four specifically designed application cases are conducted to analyze the performance benefits of the vLEC waveriders. The results of these cases indicate that, due to their variable shock angle distributions, the vLEC waveriders exhibit higher lift-to-drag ratios and better longitudinal static stability than conventional waveriders. Additionally, the vLEC waveriders demonstrate superior volumetric capacities near the symmetry plane, albeit with a minor decrease in volumetric efficiency.展开更多
Background:Although Cone reconstruction has been shown to improve biventricular functionover time,postoperative right ventricular dysfunction(RVD)is frequently observed,signiffcantly affectingreoperation and long-term...Background:Although Cone reconstruction has been shown to improve biventricular functionover time,postoperative right ventricular dysfunction(RVD)is frequently observed,signiffcantly affectingreoperation and long-term prognosis.This study aims to identify the predictors for postoperative RVD.Methods:This retrospective cohort study included 51 patients with Ebstein’s anomaly who underwentthe Cone reconstruction.RVD was deffned as right ventricular fractional area change(RV-FAC)lessthan 35%and tricuspid annular plane systolic excursion(TAPSE)less than 17 mm through pre-dischargeechocardiography.Univariate and multivariate analyses were used to analyze the pre-operative predictors.Results:The median age at surgery was 37.7(±15.3)years,RVD was documented in 25 patients(49%)of the51 patients.Patients with RVD had signiffcantly higher right ventricular end-systolic volume index(RVESVi)(p=0.001),right ventricular end-diastolic volume index(RVEDVi)(p=0.03),and septal leaffet displacement(p=0.003).Multivariate analysis conffrmed that septal leaffet displacement was independently associatedwith postoperative RVD(p=0.02).Additionally,RVD was not related to the cardiopulmonary bypass time,ICU stay and total hospital time.Conclusions:This study suggests that preoperative right ventricularejection fraction(RVEF)reduction,severe septal leaffet displacement and signiffcant right ventriculardilatation are key predictors of early postoperative RVD.RVD may exacerbate tricuspid regurgitation,andthis ffnding indicates that predicting RVD may aid in identifying high-risk patients prone to recurrence oftricuspid regurgitation after Cone reconstruction.展开更多
Objective:To observe the clinical efficacy of modified painless suppurative moxibustion with wheat-grain sized moxa cones plus Western medication in treating cough variant asthma(CVA)due to wind-cold attacking the lun...Objective:To observe the clinical efficacy of modified painless suppurative moxibustion with wheat-grain sized moxa cones plus Western medication in treating cough variant asthma(CVA)due to wind-cold attacking the lung and its effects on pulmonary function,serum immunoglobulin(Ig)-E,hypersensitive C-reactive protein(hs-CRP),and interleukin(IL)-6.Methods:A total of 98 CVA patients were randomly divided into an observation group and a control group using the random number table method,with 49 cases in each group.The control group was treated with salmeterol xinafoate and fluticasone propionate powder for inhalation,and the observation group was treated with additional modified painless suppurative moxibustion with wheat-grain sized moxa cones.The treatment lasted for 8 weeks.The traditional Chinese medicine(TCM)symptom score of the patients in both groups was observed before treatment,after treatment,and at 1-month follow-up after treatment for its changes.The clinical efficacy after treatment and at 1-month follow-up was compared between the two groups.The pulmonary function[forced expiratory volume in the first second(FEV1),FEV1/forced vital capacity(FVC),and peak expiratory flow(PEF)]and serum IgE,hs-CRP,and IL-6 levels were compared between the two groups before and after treatment.The adverse reactions that occurred during the treatment in both groups were observed and recorded.Results:The total effective rate of the observation group after treatment and at follow-up was higher than that of the control group(P<0.05).The TCM symptom scores in both groups after treatment and at follow-up were lower compared to the baseline(P<0.05),and the scores in the observation group were lower than those in the control group(P<0.05).The FEV1,FEV1/FVC,and PEF after treatment in both groups were higher compared to the baseline(P<0.05),and the levels in the observation group were higher than those in the control group(P<0.05).The serum levels of IgE,IL-6,and hs-CRP after treatment in both groups were lower than the baseline(P<0.05),and the levels in the observation group were lower than those in the control group(P<0.05).There were no adverse reactions in either group during the course of the study.Conclusion:Modified painless suppurative moxibustion with wheat-grain sized moxa cones plus salmeterol xinafoate and fluticasone propionate powder for inhalation is effective in treating CVA due to wind-cold attacking the lung;it can relieve the clinical symptoms of the patients,improve their pulmonary function,and also reduce serum IgE,hs-CRP,and IL-6 levels.展开更多
Field emission electric propulsion(FEEP) thrusters possess excellent characteristics, such as high specific impulse, low power requirements, compact size and precise pointing capabilities,making them ideal propulsion ...Field emission electric propulsion(FEEP) thrusters possess excellent characteristics, such as high specific impulse, low power requirements, compact size and precise pointing capabilities,making them ideal propulsion devices for micro-nano satellites. However, the detection of certain aspects, such as the evolution process of the liquid cone and the physical quantities at the cone apex, proves challenging due to the minute size of the needle tip and the vacuum environment in which they operate. Consequently, this paper introduces a computational fluid dynamics(CFD) model to gain insight into the formation process of the liquid cone on the tip apex of indium FEEP. The CFD model is based on electrohydrodynamic(EHD) equations and the volume of fluid(VOF) method. The entire cone formation process can be divided into three stages, and the time-dependent characteristics of the physical quantities at the cone apex are investigated. The influences of film thickness, apex radius size and applied voltage are compared.The results indicate a gradual increase in the values of electrostatic stress and surface tension stress at the cone apex over an initial period, followed by a rapid escalation within a short duration.Apex configurations featuring a small radius, thick film and high voltage exhibit a propensity for liquid cone formation, and the cone growth time decreases as the film thickness increases.Moreover, some unstable behavior is observed during the cone formation process.展开更多
The interpretation of the cone penetration test(CPT)still relies largely on empirical correlations that have been predominantly developed in resource-intensive and time-consuming calibration chambers.This paper presen...The interpretation of the cone penetration test(CPT)still relies largely on empirical correlations that have been predominantly developed in resource-intensive and time-consuming calibration chambers.This paper presents a CPT virtual calibration chamber using deep learning(DL)approaches,which allow for the consideration of depth-dependent cone resistance profiles through the implementation of two proposed strategies:(1)depth-resistance mapping using a multilayer perceptron(MLP)and(2)sequence-to-sequence training using a long short-term memory(LSTM)neural network.Two DL models are developed to predict cone resistance profiles(qc)under various soil states and testing conditions,where Bayesian optimization(BO)is adopted to identify the optimal hyperparameters.Subsequently,the BO-MLP and BO-LSTM networks are trained using the available data from published datasets.The results show that the models with BO can effectively improve the prediction accuracy and efficiency of neural networks compared to those without BO.The two training strategies yielded comparable results in the testing set,and both can be used to reproduce the whole cone resistance profile.An extended comparison and validation of the prediction results are carried out against numerical results obtained from a coupled Eulerian-Lagrangian(CEL)model,demonstrating a high degree of agreement between the DL and CEL models.Ultimately,to demonstrate the usability of this new virtual calibration chamber,the predicted qc is used to enhance the preceding correlations with the relative density(Dr)of the sand.The improved correlation with superior generalization has an R^(2) of 82%when considering all data,and 89.6%when examining the pure experimental data.展开更多
The present paper examines the temperature-dependent viscosity and thermal conductivity of a micropolar silver(Ag)−Magnesium oxide(MgO)hybrid nanofluid made of silver and magnesium oxide over a rotating vertical cone,...The present paper examines the temperature-dependent viscosity and thermal conductivity of a micropolar silver(Ag)−Magnesium oxide(MgO)hybrid nanofluid made of silver and magnesium oxide over a rotating vertical cone,with the influence of transverse magnetic field and thermal radiation.The physical flow problem has been modeled with coupled partial differential equations.We apply similarity transformations to the nondimensionalized equations,and the resulting nonlinear differential equations are solved using overlapping grid multidomain spectral quasilinearization method.The flow behavior for the fluid is scrutinized under the impact of diverse physical constraints,which are illustrated graphically.The results of the skin friction coefficient and Nusselt number varying different flow parameters are presented in the form of a table.It is observed that the main flow of the hybrid nanofluid,nano particle fraction of silver and Magnesium/water,enhances compared to the mono-nano fluid MgO as the coupling number increases.The application of studies like this can be found in the atomization process of liquids such as centrifugal pumps,viscometers,rotors,fans.展开更多
In order to obtain the reasonable undrained shear strength Su for geotechnical analyses of bridge foundations in Yangtze River floodplain clayey soils, a site-specific study is conducted using the imported piezocone p...In order to obtain the reasonable undrained shear strength Su for geotechnical analyses of bridge foundations in Yangtze River floodplain clayey soils, a site-specific study is conducted using the imported piezocone penetration test （CPTu） with dissipation phases at the Fourth Nanjing Yangtze River Bridge construction sites. Taking the values of Su from laboratory tests as references, several existing Su-predicted methods based on CPTu are compared and evaluated. To verify the presented cone factor Nk, additional test sites are selected and examined. The results show that the values of cone factors such as Nkt, Nke, and Nau, depend on the shear test mode and disturbance. Generally, the values of Nke show more scattering than those of Nkt and N△u. For the stratified and layered sediments of the Yangtze River floodplain, it is recommended using the net cone resistance qT to estimate Su and the preliminary cone factor values Nkt are from 7 to 16, with an average of 11. It is also confirmed that the CPTu test, as a new technique in site characterization, can present reasonable parameters for bridge foundations.展开更多
The author gives a dual characterization of solid cones in locally convex spaces. From this the author obtains some criteria for judging convex cones to be solid in various kinds of locally convex spaces. Using a gene...The author gives a dual characterization of solid cones in locally convex spaces. From this the author obtains some criteria for judging convex cones to be solid in various kinds of locally convex spaces. Using a general expression of the interior of a solid cone, the author obtains a number of necessary and sufficient conditions for convex cones to be solid in the framework of Banach spaces. In particular, the author gives a dual relationship between solid cones and generalized sharp cones. The related known results are improved and extended.展开更多
A multicriterion clustering model with cone dominated structure is established and the concept of cone-efficient clustering is put forward. The properties of cone-efficient clustering are disscussed, and a method to s...A multicriterion clustering model with cone dominated structure is established and the concept of cone-efficient clustering is put forward. The properties of cone-efficient clustering are disscussed, and a method to solve multicriterion clustering is put forward.The model of Ref.[3] is a special case of that proposed in this paper.展开更多
Novel headstand pyrocarbon cones （HPCs） with hollow structure were developed on the surfaces of pyrocarbon layers of the carbon/carbon （C/C） composites at 650-750 °C by the electromagnetic-field-assisted chem...Novel headstand pyrocarbon cones （HPCs） with hollow structure were developed on the surfaces of pyrocarbon layers of the carbon/carbon （C/C） composites at 650-750 °C by the electromagnetic-field-assisted chemical vapor deposition in the absence of catalysts. The fine microstructures of the HPCs were characterized by high-resolution transmission electron microscopy. The results show that the textural features of the HPCs directly transfer from turbostratic structure in roots to a well-ordered high texture in stems. And the degree of high texture ordering decreases gradually from the stem to the tail of the HPCs. The formation mechanism of the HPCs was inferred as the comprehensive effect of polarization induction on electromagnetic fields and particle-filler property under disruptive discharge.展开更多
文摘The rapid prediction of aerodynamic performance is critical in the conceptual and preliminary design of hypersonic vehicles. This study focused on axisymmetric body configurations commonly used in such vehicles and proposed a multi-fidelity neural network (MFNN) framework to fuse aerodynamic data of varying quality. A data-driven prediction model was constructed using a pointwise modeling method based on generating lines to input geometric features into the network. The MFNN framework combined low-fidelity and high-fidelity networks, trained on aerodynamic performance data from engineering rapid computation methods and CFD, respectively, using spherically blunted cones as examples. The results showed that the MFNN effectively integrated multi-fidelity data, achieving prediction accuracy close to CFD results in most regions, with errors under 5% in key stagnation areas. The model demonstrated strong generalization capabilities for varying cone dimensions and flight conditions. Furthermore, it significantly reduced dependence on high-fidelity data, enabling efficient aerodynamic performance predictions with limited datasets. This study provides a novel methodology for rapid aerodynamic performance prediction, offering both accuracy and efficiency, and contributes to the design of hypersonic vehicles.
基金Supported by the Major Project of Basic and Applied Basic Research of Guangdong Province,China(2020B0301030008)the Natural Science Foundation of China(1935007,11805167)。
文摘When an energetic parton traverses the hot QCD medium,it may suffer from multiple scattering and lose its energy.The medium-induced gluon radiation for a massive quark will be suppressed relative to that of a light quark due to the dead-cone effect.The development of new declustering techniques of jet evolution makes a direct study of the dead-cone effect in the QCD medium possible for the first time.In this work,we compute the emission angle distribution of the charm-quark-initiated splittings in D^(0) meson tagged jet and that of the light parton-initiated splittings in an inclusive jet in p+p and Pb+Pb at 5.02 TeV by utilizing the declustering techniques of jet evolution.The heavy quark propagation and induced energy loss in the QCD medium are simulated with the SHELL model based on the Langevin equation.By directly comparing the emission angle distributions of charm-quark-initiated splittings with those of light parton-initiated splittings at the same energy intervals of the initial parton,we provide insights into the fundamental splitting structure in A+A collisions,thereby exploring the possible observation of the dead-cone effect in medium-induced radiation.We further investigate the case of the emission angle distributions normalized to the number of splittings and find the dead-cone effect will broaden the emission angle of the splitting and reduce the possibility for such splitting to occur,leading the massive parton to lose less energy.We also find that the collisional energy loss mechanism has a negligible impact on the medium modification to the emission angle distribution of the charm-quark-initiated splittings for D^(0) meson-tagged jets.
基金Supported by the National Natural Science Foundation of China under Grant No.51965032the Natural Science Foundation of Gansu Province of China under Grant No.22JR5RA319+2 种基金the Excellent Doctoral Student Foundation of Gansu Province of China under Grant No.23JRRA842the Sichuan Province Engineering Technology Research Center of General Aircraft Maintenance under Grant No.GAMRC2023YB05the Key Research and Development Project of Lanzhou Jiaotong University under Grant No.LZJTUZDYF2302.
文摘Currently,the cranes used at sea do not have enough flexibility,efficiency,and safety.Thus,this study proposed a floating multirobot coordinated towing system to meet the demands for offshore towing.Because of the flexibility of rope-driven robots,the one-way pulling characteristics of the rope,and the floating characteristics of the base,towing robots are easily overturned.First,the spatial configuration of the towing system was established according to the towing task,and the kinematic model of the towing system was established using the coordinate transformation.Then,the dynamic model of the towing system was established according to the rigid-body dynamics and hydrodynamic theory.Finally,the stability of the towing system was analyzed using the stability cone method.The simulation experiments provide a reference for the practical application of the floating multirobot coordinated towing system,which can improve the stability of towing systems by changing the configuration of the towing robot.
基金supported by the National Natural Science Foundation of China(No.12271419).
文摘In this paper,we consider the symmetric cone linear complementarity problem with the Cartesian P0-property and present a regularization smoothing method with a nonmonotone line search to solve this problem.It has been demonstrated that the proposed method exhibits global convergence under the condition that the solution set of the complementarity problem is nonempty.This condition is less stringent than those that have appeared in some existing literature.We also show that the method has locally quadratic convergence under appropriate conditions.Some experimental results are reported to illustrate the efficiency of the proposed method.
文摘For cone beam computed tomography(CBCT),there has long been a desire to modulate the intensity and distribution of the X-rays to accommodate the patient’s anatomy as the gantry rotates from one projection to another.This would reduce both image artifacts and radiation dose.However,the current beam modulation setups,such as dynamic bowtie filters,may be too complex for practical use in clinical applications.This study aimed to investigate a simplified dynamic beam filtration strategy for CBCT imaging to reduce image artifacts and radiation dose.In this study,the beam filtration was designed to vary dynamically as the CBCT gantry rotates around the object.Specifically,two distinct components were integrated:the sheet filter part and the bowtie filter part.The dynamic beam filtration setup has two working schemes,one is a combination of dynamic sheet filter and dynamic bowtie filter,denoted as dynamic filterdynamic bowtie(DFDB);the other is a combination of dynamic sheet filter and static bowtie filter,denoted as dynamic filter-static bowtie(DFSB).Numerical imaging experiments were performed for three human body parts:the shoulder,chest,and knee.In addition,the Monte Carlo simulation platform MC-GPU was used to generate the dose distribution maps.Results showed that the proposed DFDB and DFSB beam filtration schemes can significantly reduce the image artifacts and thus improve the CBCT image quality.Depending on the scanned object,the total radiation dose could be reduced by 30%.The proposed simple dynamic beam filtration strategy,especially the DFSB approach,could be beneficial in the future to improve the CBCT image quality with reduced image artifacts and radiation dose.
基金supported by grants from the National Natural Science Foundation of China(No.U20B2006)the Guangdong Basic and Applied Basic Research Foundation(No.2022A1515110145)Young Elite Scientists Sponsorship Program by China Association for Science and Technology(No.2022QNRC001).
文摘The optimization of the waverider is constrained by the reversely designed leading edge and the constant shock angle distribution. This paper proposes a design method called the variable Leading-Edge Cone (vLEC) method to address these limitations. In the vLEC method, the waverider is directly designed from the preassigned leading edge and the variable shock angle distribution based on the Leading-Edge Cone (LEC) concept. Since the vLEC method is an approximate method, two test waveriders are designed and evaluated using numerical simulations to validate the shock design accuracy and the effectiveness of the vLEC method. The results show that the shocks of the test waveriders coincide well with the preassigned positions. Furthermore, four specifically designed application cases are conducted to analyze the performance benefits of the vLEC waveriders. The results of these cases indicate that, due to their variable shock angle distributions, the vLEC waveriders exhibit higher lift-to-drag ratios and better longitudinal static stability than conventional waveriders. Additionally, the vLEC waveriders demonstrate superior volumetric capacities near the symmetry plane, albeit with a minor decrease in volumetric efficiency.
基金funded by E Fund Congenital Heart Disease Medical Talent Cultivation and Education Fund(grant number[2023QT0009])the Science and Technology Planning Project of Guangdong Province(grant number[2023B03J1255]).
文摘Background:Although Cone reconstruction has been shown to improve biventricular functionover time,postoperative right ventricular dysfunction(RVD)is frequently observed,signiffcantly affectingreoperation and long-term prognosis.This study aims to identify the predictors for postoperative RVD.Methods:This retrospective cohort study included 51 patients with Ebstein’s anomaly who underwentthe Cone reconstruction.RVD was deffned as right ventricular fractional area change(RV-FAC)lessthan 35%and tricuspid annular plane systolic excursion(TAPSE)less than 17 mm through pre-dischargeechocardiography.Univariate and multivariate analyses were used to analyze the pre-operative predictors.Results:The median age at surgery was 37.7(±15.3)years,RVD was documented in 25 patients(49%)of the51 patients.Patients with RVD had signiffcantly higher right ventricular end-systolic volume index(RVESVi)(p=0.001),right ventricular end-diastolic volume index(RVEDVi)(p=0.03),and septal leaffet displacement(p=0.003).Multivariate analysis conffrmed that septal leaffet displacement was independently associatedwith postoperative RVD(p=0.02).Additionally,RVD was not related to the cardiopulmonary bypass time,ICU stay and total hospital time.Conclusions:This study suggests that preoperative right ventricularejection fraction(RVEF)reduction,severe septal leaffet displacement and signiffcant right ventriculardilatation are key predictors of early postoperative RVD.RVD may exacerbate tricuspid regurgitation,andthis ffnding indicates that predicting RVD may aid in identifying high-risk patients prone to recurrence oftricuspid regurgitation after Cone reconstruction.
文摘Objective:To observe the clinical efficacy of modified painless suppurative moxibustion with wheat-grain sized moxa cones plus Western medication in treating cough variant asthma(CVA)due to wind-cold attacking the lung and its effects on pulmonary function,serum immunoglobulin(Ig)-E,hypersensitive C-reactive protein(hs-CRP),and interleukin(IL)-6.Methods:A total of 98 CVA patients were randomly divided into an observation group and a control group using the random number table method,with 49 cases in each group.The control group was treated with salmeterol xinafoate and fluticasone propionate powder for inhalation,and the observation group was treated with additional modified painless suppurative moxibustion with wheat-grain sized moxa cones.The treatment lasted for 8 weeks.The traditional Chinese medicine(TCM)symptom score of the patients in both groups was observed before treatment,after treatment,and at 1-month follow-up after treatment for its changes.The clinical efficacy after treatment and at 1-month follow-up was compared between the two groups.The pulmonary function[forced expiratory volume in the first second(FEV1),FEV1/forced vital capacity(FVC),and peak expiratory flow(PEF)]and serum IgE,hs-CRP,and IL-6 levels were compared between the two groups before and after treatment.The adverse reactions that occurred during the treatment in both groups were observed and recorded.Results:The total effective rate of the observation group after treatment and at follow-up was higher than that of the control group(P<0.05).The TCM symptom scores in both groups after treatment and at follow-up were lower compared to the baseline(P<0.05),and the scores in the observation group were lower than those in the control group(P<0.05).The FEV1,FEV1/FVC,and PEF after treatment in both groups were higher compared to the baseline(P<0.05),and the levels in the observation group were higher than those in the control group(P<0.05).The serum levels of IgE,IL-6,and hs-CRP after treatment in both groups were lower than the baseline(P<0.05),and the levels in the observation group were lower than those in the control group(P<0.05).There were no adverse reactions in either group during the course of the study.Conclusion:Modified painless suppurative moxibustion with wheat-grain sized moxa cones plus salmeterol xinafoate and fluticasone propionate powder for inhalation is effective in treating CVA due to wind-cold attacking the lung;it can relieve the clinical symptoms of the patients,improve their pulmonary function,and also reduce serum IgE,hs-CRP,and IL-6 levels.
基金supported by National Natural Science Foundation of China(No.52075334)。
文摘Field emission electric propulsion(FEEP) thrusters possess excellent characteristics, such as high specific impulse, low power requirements, compact size and precise pointing capabilities,making them ideal propulsion devices for micro-nano satellites. However, the detection of certain aspects, such as the evolution process of the liquid cone and the physical quantities at the cone apex, proves challenging due to the minute size of the needle tip and the vacuum environment in which they operate. Consequently, this paper introduces a computational fluid dynamics(CFD) model to gain insight into the formation process of the liquid cone on the tip apex of indium FEEP. The CFD model is based on electrohydrodynamic(EHD) equations and the volume of fluid(VOF) method. The entire cone formation process can be divided into three stages, and the time-dependent characteristics of the physical quantities at the cone apex are investigated. The influences of film thickness, apex radius size and applied voltage are compared.The results indicate a gradual increase in the values of electrostatic stress and surface tension stress at the cone apex over an initial period, followed by a rapid escalation within a short duration.Apex configurations featuring a small radius, thick film and high voltage exhibit a propensity for liquid cone formation, and the cone growth time decreases as the film thickness increases.Moreover, some unstable behavior is observed during the cone formation process.
基金support from the National Natural Science Foundation of China(Grant No.52408356)the China Scholarship Council(CSC).
文摘The interpretation of the cone penetration test(CPT)still relies largely on empirical correlations that have been predominantly developed in resource-intensive and time-consuming calibration chambers.This paper presents a CPT virtual calibration chamber using deep learning(DL)approaches,which allow for the consideration of depth-dependent cone resistance profiles through the implementation of two proposed strategies:(1)depth-resistance mapping using a multilayer perceptron(MLP)and(2)sequence-to-sequence training using a long short-term memory(LSTM)neural network.Two DL models are developed to predict cone resistance profiles(qc)under various soil states and testing conditions,where Bayesian optimization(BO)is adopted to identify the optimal hyperparameters.Subsequently,the BO-MLP and BO-LSTM networks are trained using the available data from published datasets.The results show that the models with BO can effectively improve the prediction accuracy and efficiency of neural networks compared to those without BO.The two training strategies yielded comparable results in the testing set,and both can be used to reproduce the whole cone resistance profile.An extended comparison and validation of the prediction results are carried out against numerical results obtained from a coupled Eulerian-Lagrangian(CEL)model,demonstrating a high degree of agreement between the DL and CEL models.Ultimately,to demonstrate the usability of this new virtual calibration chamber,the predicted qc is used to enhance the preceding correlations with the relative density(Dr)of the sand.The improved correlation with superior generalization has an R^(2) of 82%when considering all data,and 89.6%when examining the pure experimental data.
文摘The present paper examines the temperature-dependent viscosity and thermal conductivity of a micropolar silver(Ag)−Magnesium oxide(MgO)hybrid nanofluid made of silver and magnesium oxide over a rotating vertical cone,with the influence of transverse magnetic field and thermal radiation.The physical flow problem has been modeled with coupled partial differential equations.We apply similarity transformations to the nondimensionalized equations,and the resulting nonlinear differential equations are solved using overlapping grid multidomain spectral quasilinearization method.The flow behavior for the fluid is scrutinized under the impact of diverse physical constraints,which are illustrated graphically.The results of the skin friction coefficient and Nusselt number varying different flow parameters are presented in the form of a table.It is observed that the main flow of the hybrid nanofluid,nano particle fraction of silver and Magnesium/water,enhances compared to the mono-nano fluid MgO as the coupling number increases.The application of studies like this can be found in the atomization process of liquids such as centrifugal pumps,viscometers,rotors,fans.
基金The National Natural Science Foundation of China(No.40702047)
文摘In order to obtain the reasonable undrained shear strength Su for geotechnical analyses of bridge foundations in Yangtze River floodplain clayey soils, a site-specific study is conducted using the imported piezocone penetration test （CPTu） with dissipation phases at the Fourth Nanjing Yangtze River Bridge construction sites. Taking the values of Su from laboratory tests as references, several existing Su-predicted methods based on CPTu are compared and evaluated. To verify the presented cone factor Nk, additional test sites are selected and examined. The results show that the values of cone factors such as Nkt, Nke, and Nau, depend on the shear test mode and disturbance. Generally, the values of Nke show more scattering than those of Nkt and N△u. For the stratified and layered sediments of the Yangtze River floodplain, it is recommended using the net cone resistance qT to estimate Su and the preliminary cone factor values Nkt are from 7 to 16, with an average of 11. It is also confirmed that the CPTu test, as a new technique in site characterization, can present reasonable parameters for bridge foundations.
基金the National Natural Science Foundation of China(10571035)
文摘The author gives a dual characterization of solid cones in locally convex spaces. From this the author obtains some criteria for judging convex cones to be solid in various kinds of locally convex spaces. Using a general expression of the interior of a solid cone, the author obtains a number of necessary and sufficient conditions for convex cones to be solid in the framework of Banach spaces. In particular, the author gives a dual relationship between solid cones and generalized sharp cones. The related known results are improved and extended.
文摘A multicriterion clustering model with cone dominated structure is established and the concept of cone-efficient clustering is put forward. The properties of cone-efficient clustering are disscussed, and a method to solve multicriterion clustering is put forward.The model of Ref.[3] is a special case of that proposed in this paper.
基金Project (2011CB605801) supported by the National Basic Research Program of ChinaProject (2011M500127) supported by the China Postdoctoral Science Foundation+1 种基金Projects (50802115, 51102089) supported by the National Natural Science Foundation of ChinaProject supported by the Postdoctoral Fund of the Central South University, China
文摘Novel headstand pyrocarbon cones （HPCs） with hollow structure were developed on the surfaces of pyrocarbon layers of the carbon/carbon （C/C） composites at 650-750 °C by the electromagnetic-field-assisted chemical vapor deposition in the absence of catalysts. The fine microstructures of the HPCs were characterized by high-resolution transmission electron microscopy. The results show that the textural features of the HPCs directly transfer from turbostratic structure in roots to a well-ordered high texture in stems. And the degree of high texture ordering decreases gradually from the stem to the tail of the HPCs. The formation mechanism of the HPCs was inferred as the comprehensive effect of polarization induction on electromagnetic fields and particle-filler property under disruptive discharge.
