In this paper, we present a nonorthogonal overlapping Yee method for solv- ing Maxwell's equations using the diagonal split-cell model. When material interface is presented, the diagonal split-cell model does not req...In this paper, we present a nonorthogonal overlapping Yee method for solv- ing Maxwell's equations using the diagonal split-cell model. When material interface is presented, the diagonal split-cell model does not require permittivity averaging so that better accuracy can be achieved. Our numerical results on optical force computation show that the standard FDTD method converges linearly, while the proposed method achieves quadratic convergence and better accuracy.展开更多
An online hybrid test was carried out on a 40-story 120-m high concrete shear wall structure. The structure was divided into two substructures whereby a physical model of the bottom three stories was tested in the lab...An online hybrid test was carried out on a 40-story 120-m high concrete shear wall structure. The structure was divided into two substructures whereby a physical model of the bottom three stories was tested in the laboratory and the upper 37 stories were simulated numerically using ABAQUS. An overlapping domain method was employed for the bottom three stories to ensure the validity of the boundary conditions of the superstructure. Mixed control was adopted in the test. Displacement control was used to apply the horizontal displacement, while two controlled force actuators were applied to simulate the overturning moment, which is very large and cannot be ignored in the substructure hybrid test of high-rise buildings. A series of tests with earthquake sources of sequentially increasing intensities were carried out. The test results indicate that the proposed hybrid test method is a solution to reproduce the seismic response of high-rise concrete shear wall buildings. The seismic performance of the tested precast high-rise building satisfies the requirements of the Chinese seismic design code.展开更多
In order to establish a new method for measuring the dimensions of coarse aggregates, five different-size flat and elongated (F&E) coarse aggregates were glued into two specimens by epoxy resin, respectively, and ...In order to establish a new method for measuring the dimensions of coarse aggregates, five different-size flat and elongated (F&E) coarse aggregates were glued into two specimens by epoxy resin, respectively, and slice images were obtained by X-ray CT, then the aggregates were extracted by the fuzzy c-means clustering algorithm. Attributions of the particle on different cross-sections were determined by the ‘overlap area method’. And unified three-dimensional Cartesian coordinate system was established based on continuous slice images. The coefficient values of spherical harmonics descriptor representing particles surface profile were gained, then each scanned particle was represented by 60×120 discrete points conformably with spherical harmonics descriptor. The chord length and direction angles were determined by the calculation. With the major axis (L) and orthogonal axis (W and T), the calculated results were compared with those measured by caliper. It is concluded that the new L, W, and T dimension measuring method is able to take the place of the present manual measurement.展开更多
The present study investigates the axisymmetric stagnation point radiativeflow of a Cu-Al2O3/water hybrid nanofluid over a radially stretched/shrunk disk.In this paper,a new mathematical model has been developed by ta...The present study investigates the axisymmetric stagnation point radiativeflow of a Cu-Al2O3/water hybrid nanofluid over a radially stretched/shrunk disk.In this paper,a new mathematical model has been developed by taking into consideration the concept of different nanoparticles concentration in a hybrid nanofluid,which are Brownian motion and thermophor-esis of nanoparticles.A new model for entropy generation has also been provided in the present study.The non-dimensional governing equations of the developed mathematical model are solved using newly developed and efficient overlapping grid spectral collocation method.Numerical stability and residual error test are provided here to show the accuracy of the numer-ical method in this mathematical model.The outcomes offluidflow,temperature,and two different types of concentration profiles are depicted,and described in graphical and tabular forms.For the limiting instances,comparison shows excellent agreement among current and results established in the literature.Increasing the strength of magneticfield is seen to increase the radial component offluid velocity as well as the entropy generated within the system.Two different nanofluid concentration profiles are increasing and decreasing with rising thermophor-esis and Brownian motion parameters,respectively,from a particular height above the disk because of the revised nanofluid boundary condition.Temperature profile increases here with increasing Biot number,and increasing Brinkman number causes higher entropy generation number for both stretching and shrinking disks.The enhanced thermal characteristics of the hybrid nanofluid over the single particle nanofluid has been observed.ª2024 The Authors.Publishing services by Elsevier B.V.on behalf of KeAi Communications Co.Ltd.展开更多
This paper presents a case study on an ultra-deep diaphragm wall with a depth of 110 m constructed in Ningbo City. The in-situ application shows that using Bauer BC40 cutter machine in conjunction with cutter wheels s...This paper presents a case study on an ultra-deep diaphragm wall with a depth of 110 m constructed in Ningbo City. The in-situ application shows that using Bauer BC40 cutter machine in conjunction with cutter wheels specified for different strata would be qualified for constructing the 110 m diaphragm wall with high efficiency and precision given that the quality of slurry and poured concrete can be guaranteed. The ground settlement can be effectively controlled by using the overlapping construction method. Sliding failure as a whole characterized by pronounced lateral deformation is likely to occur in the upper muddy clay layer due to its high compressibility and sensitivity. In contrast, local collapse of trench walls tends to happen in the sandy silt strata. Furthermore, careful attention should be paid to sandy silt during the entire construction period as the vertical displacement of the sandy silt continues to develop even atter concrete pouring.展开更多
Gansu Province in the northwest of China, so the research on the impact of delay retirement in Gansu province have a certain representation. This paper analyzes the current situation of human resources in Gansu provin...Gansu Province in the northwest of China, so the research on the impact of delay retirement in Gansu province have a certain representation. This paper analyzes the current situation of human resources in Gansu province the proportion of the labor force is relatively low, the age structure of aging, education, human resources quality is still not high, the use of theoretical analysis method of overlapping generations model and AHP method to verify the proposed implementation. The delay retirement policy to increase the effective adjustment of Gansu province to improve the structure of human resources, better solve the problem of human resources structure in Gansu Province, so as to enhance Gansu's core competitive advantage.展开更多
Existing groupwise dimension reduction requires given group structure to be non-overlapped. This confines its application scope. We aim at groupwise dimension reduction with overlapped group structure or even unknown ...Existing groupwise dimension reduction requires given group structure to be non-overlapped. This confines its application scope. We aim at groupwise dimension reduction with overlapped group structure or even unknown group structure. To this end, existing groupwise dimension reduction concept is extended to be compatible with overlapped group structure. Then, the envelope method is ameliorated to deal with overlapped groupwise dimension reduction. As an application, Gaussian graphic model is employed to estimate the structure between predictors when the group structure is not given, and the amended envelope method is used for groupwise dimension reduction with graphic structure. Furthermore, the rationale of the proposed estimation procedure is explained at the population level and the estimation consistency is proved at the sample level. Finally, the finite sample performance of the proposed methods is examined via numerical simulations and a body fat data analysis.展开更多
基金supported by the Air Force Office of Scientific Research (AFOSR) under Grant numbers FA9550-04-1-0213 and FA9550-07-1-0010
文摘In this paper, we present a nonorthogonal overlapping Yee method for solv- ing Maxwell's equations using the diagonal split-cell model. When material interface is presented, the diagonal split-cell model does not require permittivity averaging so that better accuracy can be achieved. Our numerical results on optical force computation show that the standard FDTD method converges linearly, while the proposed method achieves quadratic convergence and better accuracy.
基金State Key Research Project in 13th Five-Year under Grant No.2016YFC0701901the Beijing Science and Technology Program under Grant No.Z161100001216015the Natural Science Foundation of China under Grants Nos.51422809 and 51778342
文摘An online hybrid test was carried out on a 40-story 120-m high concrete shear wall structure. The structure was divided into two substructures whereby a physical model of the bottom three stories was tested in the laboratory and the upper 37 stories were simulated numerically using ABAQUS. An overlapping domain method was employed for the bottom three stories to ensure the validity of the boundary conditions of the superstructure. Mixed control was adopted in the test. Displacement control was used to apply the horizontal displacement, while two controlled force actuators were applied to simulate the overturning moment, which is very large and cannot be ignored in the substructure hybrid test of high-rise buildings. A series of tests with earthquake sources of sequentially increasing intensities were carried out. The test results indicate that the proposed hybrid test method is a solution to reproduce the seismic response of high-rise concrete shear wall buildings. The seismic performance of the tested precast high-rise building satisfies the requirements of the Chinese seismic design code.
基金Project(51038004) supported by the National Natural Science Foundation of ChinaProject(2009318000078) supported by the Western China Communications Construction and Technology Program, China
文摘In order to establish a new method for measuring the dimensions of coarse aggregates, five different-size flat and elongated (F&E) coarse aggregates were glued into two specimens by epoxy resin, respectively, and slice images were obtained by X-ray CT, then the aggregates were extracted by the fuzzy c-means clustering algorithm. Attributions of the particle on different cross-sections were determined by the ‘overlap area method’. And unified three-dimensional Cartesian coordinate system was established based on continuous slice images. The coefficient values of spherical harmonics descriptor representing particles surface profile were gained, then each scanned particle was represented by 60×120 discrete points conformably with spherical harmonics descriptor. The chord length and direction angles were determined by the calculation. With the major axis (L) and orthogonal axis (W and T), the calculated results were compared with those measured by caliper. It is concluded that the new L, W, and T dimension measuring method is able to take the place of the present manual measurement.
基金support of the North-Eastern Hill University,Shillong-793022,Meghalaya,Indiathe University of South Africa,Corner Christian de Wet and Pioneer Avenue,Florida Park,Roodepoort,1709,South Africa.
文摘The present study investigates the axisymmetric stagnation point radiativeflow of a Cu-Al2O3/water hybrid nanofluid over a radially stretched/shrunk disk.In this paper,a new mathematical model has been developed by taking into consideration the concept of different nanoparticles concentration in a hybrid nanofluid,which are Brownian motion and thermophor-esis of nanoparticles.A new model for entropy generation has also been provided in the present study.The non-dimensional governing equations of the developed mathematical model are solved using newly developed and efficient overlapping grid spectral collocation method.Numerical stability and residual error test are provided here to show the accuracy of the numer-ical method in this mathematical model.The outcomes offluidflow,temperature,and two different types of concentration profiles are depicted,and described in graphical and tabular forms.For the limiting instances,comparison shows excellent agreement among current and results established in the literature.Increasing the strength of magneticfield is seen to increase the radial component offluid velocity as well as the entropy generated within the system.Two different nanofluid concentration profiles are increasing and decreasing with rising thermophor-esis and Brownian motion parameters,respectively,from a particular height above the disk because of the revised nanofluid boundary condition.Temperature profile increases here with increasing Biot number,and increasing Brinkman number causes higher entropy generation number for both stretching and shrinking disks.The enhanced thermal characteristics of the hybrid nanofluid over the single particle nanofluid has been observed.ª2024 The Authors.Publishing services by Elsevier B.V.on behalf of KeAi Communications Co.Ltd.
基金Funded by the National Basic Research Program of China(973 Program,No.2014CB046905)the National Natural Science Foundation of China(Grant Nos.41172249 and 51509186)+1 种基金the State Key Laboratory for Geomechanics and Deep Underground Engineering(No.SKLGDUEK1303)the funding provided by Zhuhai Da Heng Qin Company Limited(Grant No.SG25-2014-173B1)
文摘This paper presents a case study on an ultra-deep diaphragm wall with a depth of 110 m constructed in Ningbo City. The in-situ application shows that using Bauer BC40 cutter machine in conjunction with cutter wheels specified for different strata would be qualified for constructing the 110 m diaphragm wall with high efficiency and precision given that the quality of slurry and poured concrete can be guaranteed. The ground settlement can be effectively controlled by using the overlapping construction method. Sliding failure as a whole characterized by pronounced lateral deformation is likely to occur in the upper muddy clay layer due to its high compressibility and sensitivity. In contrast, local collapse of trench walls tends to happen in the sandy silt strata. Furthermore, careful attention should be paid to sandy silt during the entire construction period as the vertical displacement of the sandy silt continues to develop even atter concrete pouring.
文摘Gansu Province in the northwest of China, so the research on the impact of delay retirement in Gansu province have a certain representation. This paper analyzes the current situation of human resources in Gansu province the proportion of the labor force is relatively low, the age structure of aging, education, human resources quality is still not high, the use of theoretical analysis method of overlapping generations model and AHP method to verify the proposed implementation. The delay retirement policy to increase the effective adjustment of Gansu province to improve the structure of human resources, better solve the problem of human resources structure in Gansu Province, so as to enhance Gansu's core competitive advantage.
基金supported by a grant from the University Grant Council of Hong Kong of ChinaNational Natural Science Foundation of China (Grant No. 11371013)Tian Yuan Foundation for Mathematics
文摘Existing groupwise dimension reduction requires given group structure to be non-overlapped. This confines its application scope. We aim at groupwise dimension reduction with overlapped group structure or even unknown group structure. To this end, existing groupwise dimension reduction concept is extended to be compatible with overlapped group structure. Then, the envelope method is ameliorated to deal with overlapped groupwise dimension reduction. As an application, Gaussian graphic model is employed to estimate the structure between predictors when the group structure is not given, and the amended envelope method is used for groupwise dimension reduction with graphic structure. Furthermore, the rationale of the proposed estimation procedure is explained at the population level and the estimation consistency is proved at the sample level. Finally, the finite sample performance of the proposed methods is examined via numerical simulations and a body fat data analysis.