In this paper,a generalized nth-order perturbation method based on the isogeometric boundary element method is proposed for the uncertainty analysis of broadband structural acoustic scattering problems.The Burton-Mill...In this paper,a generalized nth-order perturbation method based on the isogeometric boundary element method is proposed for the uncertainty analysis of broadband structural acoustic scattering problems.The Burton-Miller method is employed to solve the problem of non-unique solutions that may be encountered in the external acoustic field,and the nth-order discretization formulation of the boundary integral equation is derived.In addition,the computation of loop subdivision surfaces and the subdivision rules are introduced.In order to confirm the effectiveness of the algorithm,the computed results are contrasted and analyzed with the results under Monte Carlo simulations(MCs)through several numerical examples.展开更多
To investigate the fire endurance of wood beams exposed to three-side fire,we conducted bearing capacity tests of two wood beams and experiments of five wood beams exposed to three-side fire.The finite element softwar...To investigate the fire endurance of wood beams exposed to three-side fire,we conducted bearing capacity tests of two wood beams and experiments of five wood beams exposed to three-side fire.The finite element software ANSYS was also used to predict the fire endurance of those beams with the indirect order coupling method.It was found that the fire endurance decreases as the load level increases,and the reduction ratio tends to decrease.In the case of a certain load level,the fire endurance is improved if the section size is increased or covered by the fire protection coating.The central deformation increases as the fire duration increases,and the ratio of increase tends to rise.On another note,an increase in the density of wood leads to a rise in the fire endurance of a given beam.From the finite element method(FEM)calculation results,the fire endurance decreases as the load level increases,and the reduction ratio tends to decrease.When the load level is greater than 0.5,the fire endurance is significantly reduced,and it does not change significantly when the load level changes.Lastly,for a load level magnitude below 0.5,the fire endurance and load level are proportional to one another.展开更多
Refined control of etched profile in microelectronic devices during plasma etching process is one of the most important tasks of front-end and back-end microelectronic devices manufacturing technologies. A comprehensi...Refined control of etched profile in microelectronic devices during plasma etching process is one of the most important tasks of front-end and back-end microelectronic devices manufacturing technologies. A comprehensive simulation of etching profile evolution requires knowledge of the etching rates at all the points of the profile surface during the etching process. Electrons do not contribute directly to the material removal, but they are the source, together with positive ions, of the profile charging that has many negative consequences on the final outcome of the process especially in the case of insulating material etching. The ability to simulate feature charging was added to the 3D level set profile evolution simulator described earlier. The ion and electron fluxes were computed along the feature using Monte Carlo method. The surface potential profiles and electric field for the entire feature were generated by solving Laplace equation using finite elements method. Calculations were performed in the case of simplified model of Ar+/CF4 non-equilibrium plasma etching of SiO2.展开更多
Particles and fields represent two major modeling paradigms in pure and applied science at all. In this paper a methodology and some of the results for three-dimensional (3D) simulations that include both field and pa...Particles and fields represent two major modeling paradigms in pure and applied science at all. In this paper a methodology and some of the results for three-dimensional (3D) simulations that include both field and particle abstractions are presented. Electromagnetic field calculations used here are based on the discrete differential form representation of the finite elements method, while the Monte Carlo method makes foundation of the particle part of the simulations. The first example is the simulation of the feature profile evolution during SiO2 etching enhanced by Ar + /CF4 non-equilibrium plasma based on the sparse field method for solving level set equations. Second example is devoted to the design of a spiral inflector which is one of the key devices of the axial injection system of the VINCY Cyclotron.展开更多
In Garze Tibetan autonomous prefecture inSichuan province, China, 41 echinococciasis patientswho had received surgical treatment were recruitedin the study, and 82 health persons who had livedin Garze for at least 10 ...In Garze Tibetan autonomous prefecture inSichuan province, China, 41 echinococciasis patientswho had received surgical treatment were recruitedin the study, and 82 health persons who had livedin Garze for at least 10 years were selected ascontrols. The serum levels of Zn, Se and Cu of thecases and controls were detected. The resultsshowed that most echinococciasis cases weredistributed in Shiqu county （17.1%, 7/41）, and only1 case was distributed in Yajiang county （2.4%）. Themale to female ratio of the cases was 1：1.56. Theechinococciasis patients were mainly aged 30-39years （36.59%, 15/41）. And, the cases aged 20-49years accounted for 68.29% （28/41）. Comparedwith health controls, the serum levels of Zn and Seof the cases significantly declined. However, theserum level of Cu of the cases had no significantlychange. It was confirmed that the serum levels ofZn and Se were interrelated with the prevalence ofechinococciasis.展开更多
基金sponsored by the Graduate Student Research and Innovation Fund of Xinyang Normal University under No.2024KYJJ012.
文摘In this paper,a generalized nth-order perturbation method based on the isogeometric boundary element method is proposed for the uncertainty analysis of broadband structural acoustic scattering problems.The Burton-Miller method is employed to solve the problem of non-unique solutions that may be encountered in the external acoustic field,and the nth-order discretization formulation of the boundary integral equation is derived.In addition,the computation of loop subdivision surfaces and the subdivision rules are introduced.In order to confirm the effectiveness of the algorithm,the computed results are contrasted and analyzed with the results under Monte Carlo simulations(MCs)through several numerical examples.
基金Project supported by the National Natural Science Foundation of China(No.51178115)the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe Shanghai Rising-Star Program(Nos.11QH1402100 and 07QB14031),China
文摘To investigate the fire endurance of wood beams exposed to three-side fire,we conducted bearing capacity tests of two wood beams and experiments of five wood beams exposed to three-side fire.The finite element software ANSYS was also used to predict the fire endurance of those beams with the indirect order coupling method.It was found that the fire endurance decreases as the load level increases,and the reduction ratio tends to decrease.In the case of a certain load level,the fire endurance is improved if the section size is increased or covered by the fire protection coating.The central deformation increases as the fire duration increases,and the ratio of increase tends to rise.On another note,an increase in the density of wood leads to a rise in the fire endurance of a given beam.From the finite element method(FEM)calculation results,the fire endurance decreases as the load level increases,and the reduction ratio tends to decrease.When the load level is greater than 0.5,the fire endurance is significantly reduced,and it does not change significantly when the load level changes.Lastly,for a load level magnitude below 0.5,the fire endurance and load level are proportional to one another.
基金The Ministry of Education and Science, Republic of Serbai, Projects O171037 and III41011
文摘Refined control of etched profile in microelectronic devices during plasma etching process is one of the most important tasks of front-end and back-end microelectronic devices manufacturing technologies. A comprehensive simulation of etching profile evolution requires knowledge of the etching rates at all the points of the profile surface during the etching process. Electrons do not contribute directly to the material removal, but they are the source, together with positive ions, of the profile charging that has many negative consequences on the final outcome of the process especially in the case of insulating material etching. The ability to simulate feature charging was added to the 3D level set profile evolution simulator described earlier. The ion and electron fluxes were computed along the feature using Monte Carlo method. The surface potential profiles and electric field for the entire feature were generated by solving Laplace equation using finite elements method. Calculations were performed in the case of simplified model of Ar+/CF4 non-equilibrium plasma etching of SiO2.
基金supported by O171037,Ⅲ 41011 and Ⅲ45006 Projects of Ministry of Education and Science,Serbia.
文摘Particles and fields represent two major modeling paradigms in pure and applied science at all. In this paper a methodology and some of the results for three-dimensional (3D) simulations that include both field and particle abstractions are presented. Electromagnetic field calculations used here are based on the discrete differential form representation of the finite elements method, while the Monte Carlo method makes foundation of the particle part of the simulations. The first example is the simulation of the feature profile evolution during SiO2 etching enhanced by Ar + /CF4 non-equilibrium plasma based on the sparse field method for solving level set equations. Second example is devoted to the design of a spiral inflector which is one of the key devices of the axial injection system of the VINCY Cyclotron.
基金financially supported by the Grant for the National Major Science and Technology Project(grant No.2012ZX10004-220,No.2008ZX10004-011)
文摘In Garze Tibetan autonomous prefecture inSichuan province, China, 41 echinococciasis patientswho had received surgical treatment were recruitedin the study, and 82 health persons who had livedin Garze for at least 10 years were selected ascontrols. The serum levels of Zn, Se and Cu of thecases and controls were detected. The resultsshowed that most echinococciasis cases weredistributed in Shiqu county （17.1%, 7/41）, and only1 case was distributed in Yajiang county （2.4%）. Themale to female ratio of the cases was 1：1.56. Theechinococciasis patients were mainly aged 30-39years （36.59%, 15/41）. And, the cases aged 20-49years accounted for 68.29% （28/41）. Comparedwith health controls, the serum levels of Zn and Seof the cases significantly declined. However, theserum level of Cu of the cases had no significantlychange. It was confirmed that the serum levels ofZn and Se were interrelated with the prevalence ofechinococciasis.
