Graphene nanoplates(GNPs)and carbon nanotubes(CNTs)can construct efficient thermal flux channels in composites,which is becoming one of the effective methods to improve thermal conductivity(TC)of composites.In this pa...Graphene nanoplates(GNPs)and carbon nanotubes(CNTs)can construct efficient thermal flux channels in composites,which is becoming one of the effective methods to improve thermal conductivity(TC)of composites.In this paper,an emerging class of GNPs&MWCNTs preform with 3D orientated structures were prepared by using electrostatic self-assembly and directional freeze-drying methods,and then fabricated the GNPs&MWCNTs reinforced AZ91D magnesium(GNPs&MWCNTs/AZ91D)composites by squeeze casting process.To ensure the well preparation of the composites,the GNPs&MWCNTs preforms need to possess enough compression strength to withstand squeezing pressure.Therefore,the effects of the electrostatic self-assembly process,directional freeze drying process and thermal reduction process on the compression strength of 3D structure GNPs&MWCNTs preforms were studied.The compression strength of GNPs&MWCNTs preforms were well improved to 98 KPa,which were used for the fabrication of AZ91D matrix composites.The TC of 0.5 wt.%(1:1)GNPs&MWCNTs/AZ91D composites reached 71.7 W/(m·K)in the freezing direction,which was 41.8%higher than that(50.6 W/(m·K))of the AZ91D alloy.This work provides a novel method for preparing GNPs&MWCNTs/AZ91D composites with improved TCs.展开更多
This paper has been done on study kinematic problem of Persian joint in a general way. In this study, instead of using simulation analysis method as in the previous researches, the 3D rotation matrix method is applied...This paper has been done on study kinematic problem of Persian joint in a general way. In this study, instead of using simulation analysis method as in the previous researches, the 3D rotation matrix method is applied to present the relationship of angular velocities of input shaft and output shaft. The result shows that when the angle between intersecting shafts changes from 0 to 135°, the angular velocity is maintained constant. This new result completely matches with analysis from kinematic simulation of this mechanism. The obtained result is an important base to solve dynamic problem in order to develop the applicability of this joint in reality.展开更多
Since the efficiency of treatment of thyroid disorder depends on the risk of malignancy, indeterminate follicular neoplasm (FN) images should be classified. The diagnosis process has been done by visual interpretation...Since the efficiency of treatment of thyroid disorder depends on the risk of malignancy, indeterminate follicular neoplasm (FN) images should be classified. The diagnosis process has been done by visual interpretation of experienced pathologists. However, it is difficult to separate the favor benign from borderline types. Thus, this paper presents a classification approach based on 3D nuclei model to classify favor benign and borderline types of follicular thyroid adenoma (FTA) in cytological specimens. The proposed method utilized 3D gray level co-occurrence matrix (GLCM) and random forest classifier. It was applied to 22 data sets of FN images. Furthermore, the use of 3D GLCM was compared with 2D GLCM to evaluate the classification results. From experimental results, the proposed system achieved 95.45% of the classification. The use of 3D GLCM was better than 2D GLCM according to the accuracy of classification. Consequently, the proposed method probably helps a pathologist as a prescreening tool.展开更多
On the base of study of the correlation of fault tree's main data-minimum cutsets, minimum path sets, non-intersect minimum cut sets and non-intersect minimum path sets,transformation method among main data are fo...On the base of study of the correlation of fault tree's main data-minimum cutsets, minimum path sets, non-intersect minimum cut sets and non-intersect minimum path sets,transformation method among main data are found, i.e. the transformation can be realized by theoperation of cut sets matrixes. This method provides anew way to reduce 'NP' difficulty and simplifyFTA.展开更多
This paper studies the eigenfunction expansion method to solve the two dimensional （2D） elasticity problems based on the stress formulation. The fundamental system of partial differential equations of the 2D problem...This paper studies the eigenfunction expansion method to solve the two dimensional （2D） elasticity problems based on the stress formulation. The fundamental system of partial differential equations of the 2D problems is rewritten as an upper tri angular differential system based on the known results, and then the associated upper triangular operator matrix matrix is obtained. By further research, the two simpler com plete orthogonal systems of eigenfunctions in some space are obtained, which belong to the two block operators arising in the operator matrix. Then, a more simple and conve nient general solution to the 2D problem is given by the eigenfunction expansion method. Furthermore, the boundary conditions for the 2D problem, which can be solved by this method, are indicated. Finally, the validity of the obtained results is verified by a specific example.展开更多
The problem of the robust D-stability analysis for linear systems with parametric uncertainties is addressed. For matrix polytopes, new conditions via the affine parameter-dependent Lyapunov function of uncertain syst...The problem of the robust D-stability analysis for linear systems with parametric uncertainties is addressed. For matrix polytopes, new conditions via the affine parameter-dependent Lyapunov function of uncertain systems are developed with the benefit of the scalar multi-convex function. To be convenient for applications, such conditions are simplified into new linear matrix inequality （LMI） conditions, which can be solved by the powerful LMI toolbox. Numerical examples are provided to indicate that this new approach is less conservative than previous results for Hurwitz stability, Schur stability and D-stability of uncertain systems under certain circumstances.展开更多
基金supported by the National Natural Science Foundation of China(grant numbers 52231004,51972271 and 52205415)Guangdong Basic and Applied Basic Research Foundation(No.2021A1515110034)。
文摘Graphene nanoplates(GNPs)and carbon nanotubes(CNTs)can construct efficient thermal flux channels in composites,which is becoming one of the effective methods to improve thermal conductivity(TC)of composites.In this paper,an emerging class of GNPs&MWCNTs preform with 3D orientated structures were prepared by using electrostatic self-assembly and directional freeze-drying methods,and then fabricated the GNPs&MWCNTs reinforced AZ91D magnesium(GNPs&MWCNTs/AZ91D)composites by squeeze casting process.To ensure the well preparation of the composites,the GNPs&MWCNTs preforms need to possess enough compression strength to withstand squeezing pressure.Therefore,the effects of the electrostatic self-assembly process,directional freeze drying process and thermal reduction process on the compression strength of 3D structure GNPs&MWCNTs preforms were studied.The compression strength of GNPs&MWCNTs preforms were well improved to 98 KPa,which were used for the fabrication of AZ91D matrix composites.The TC of 0.5 wt.%(1:1)GNPs&MWCNTs/AZ91D composites reached 71.7 W/(m·K)in the freezing direction,which was 41.8%higher than that(50.6 W/(m·K))of the AZ91D alloy.This work provides a novel method for preparing GNPs&MWCNTs/AZ91D composites with improved TCs.
文摘This paper has been done on study kinematic problem of Persian joint in a general way. In this study, instead of using simulation analysis method as in the previous researches, the 3D rotation matrix method is applied to present the relationship of angular velocities of input shaft and output shaft. The result shows that when the angle between intersecting shafts changes from 0 to 135°, the angular velocity is maintained constant. This new result completely matches with analysis from kinematic simulation of this mechanism. The obtained result is an important base to solve dynamic problem in order to develop the applicability of this joint in reality.
文摘Since the efficiency of treatment of thyroid disorder depends on the risk of malignancy, indeterminate follicular neoplasm (FN) images should be classified. The diagnosis process has been done by visual interpretation of experienced pathologists. However, it is difficult to separate the favor benign from borderline types. Thus, this paper presents a classification approach based on 3D nuclei model to classify favor benign and borderline types of follicular thyroid adenoma (FTA) in cytological specimens. The proposed method utilized 3D gray level co-occurrence matrix (GLCM) and random forest classifier. It was applied to 22 data sets of FN images. Furthermore, the use of 3D GLCM was compared with 2D GLCM to evaluate the classification results. From experimental results, the proposed system achieved 95.45% of the classification. The use of 3D GLCM was better than 2D GLCM according to the accuracy of classification. Consequently, the proposed method probably helps a pathologist as a prescreening tool.
文摘On the base of study of the correlation of fault tree's main data-minimum cutsets, minimum path sets, non-intersect minimum cut sets and non-intersect minimum path sets,transformation method among main data are found, i.e. the transformation can be realized by theoperation of cut sets matrixes. This method provides anew way to reduce 'NP' difficulty and simplifyFTA.
基金supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China (No. 20070126002)the National Natural Science Foundation of China (No. 10962004)
文摘This paper studies the eigenfunction expansion method to solve the two dimensional （2D） elasticity problems based on the stress formulation. The fundamental system of partial differential equations of the 2D problems is rewritten as an upper tri angular differential system based on the known results, and then the associated upper triangular operator matrix matrix is obtained. By further research, the two simpler com plete orthogonal systems of eigenfunctions in some space are obtained, which belong to the two block operators arising in the operator matrix. Then, a more simple and conve nient general solution to the 2D problem is given by the eigenfunction expansion method. Furthermore, the boundary conditions for the 2D problem, which can be solved by this method, are indicated. Finally, the validity of the obtained results is verified by a specific example.
基金supported by the National Natural Science Foundation of China (6090405161021002)
文摘The problem of the robust D-stability analysis for linear systems with parametric uncertainties is addressed. For matrix polytopes, new conditions via the affine parameter-dependent Lyapunov function of uncertain systems are developed with the benefit of the scalar multi-convex function. To be convenient for applications, such conditions are simplified into new linear matrix inequality （LMI） conditions, which can be solved by the powerful LMI toolbox. Numerical examples are provided to indicate that this new approach is less conservative than previous results for Hurwitz stability, Schur stability and D-stability of uncertain systems under certain circumstances.
