This paper presents a method to obtain the global or quasi-optimum for the discrete and continuous design variables, based on the Modified Generalized Random Tunneling Algorithm (MGRTA). By handling the discrete design variables as penalty function, the augmented objective function is constructed. As a result, all design variables can be treated as the continuous design variables. The augmented objective function becomes non-convex, and has many local minima. That is, finding optimum of discrete design variables is transformed into finding global optimum of this augmented objective function. Then the MGRTA is applied to this augmented objective function, subject to the behavior and side constraints. We also propose the new update scheme of penalty parameter for the penalty function of discrete design variables in this paper. The proposed update scheme of penalty parameter utilizes the information of the penalty function value of discrete design variables. By utilizing the characteristics of MGRTA, some optima are obtained. The validity of the proposed method is examined through typical benchmark problems.
{"title":"Global Optimization by Generalized Random Tunneling Algorithm (4th Report Application to the Nonlinear Optimum Design Problem of the Mixed Design Variables)","authors":"S. Kitayama, K. Yamazaki","doi":"10.1299/JCST.2.258","DOIUrl":"https://doi.org/10.1299/JCST.2.258","url":null,"abstract":"This paper presents a method to obtain the global or quasi-optimum for the discrete and continuous design variables, based on the Modified Generalized Random Tunneling Algorithm (MGRTA). By handling the discrete design variables as penalty function, the augmented objective function is constructed. As a result, all design variables can be treated as the continuous design variables. The augmented objective function becomes non-convex, and has many local minima. That is, finding optimum of discrete design variables is transformed into finding global optimum of this augmented objective function. Then the MGRTA is applied to this augmented objective function, subject to the behavior and side constraints. We also propose the new update scheme of penalty parameter for the penalty function of discrete design variables in this paper. The proposed update scheme of penalty parameter utilizes the information of the penalty function value of discrete design variables. By utilizing the characteristics of MGRTA, some optima are obtained. The validity of the proposed method is examined through typical benchmark problems.","PeriodicalId":196913,"journal":{"name":"Journal of Computational Science and Technology","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132156784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
3D meshes generated by acquisition devices such as laser range scanners often contain holes due to occlusion, etc. In practice, these holes are extremely geometrically and topologically complex. We propose a heuristic hole filling technique using particle systems to fill complex holes with arbitrary topology in 3D meshes. Our approach includes the following steps: hole identification, base surface creation, particle distribution, triangulation, and mesh refinement. We demonstrate the functionality of the proposed surface retouching system on synthetic and real data.
{"title":"A Software System for Filling Complex Holes in 3D Meshes by Flexible Interacting Particles","authors":"D. Yamazaki, V. Savchenko","doi":"10.1299/JCST.2.655","DOIUrl":"https://doi.org/10.1299/JCST.2.655","url":null,"abstract":"3D meshes generated by acquisition devices such as laser range scanners often contain holes due to occlusion, etc. In practice, these holes are extremely geometrically and topologically complex. We propose a heuristic hole filling technique using particle systems to fill complex holes with arbitrary topology in 3D meshes. Our approach includes the following steps: hole identification, base surface creation, particle distribution, triangulation, and mesh refinement. We demonstrate the functionality of the proposed surface retouching system on synthetic and real data.","PeriodicalId":196913,"journal":{"name":"Journal of Computational Science and Technology","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115807841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, a Trans-mesh method is presented for simulating three-dimensional incompressible fluid-rigid body interaction with collisions. In the Trans-mesh method, the bodies can move freely in a main mesh that covers the entire flow field. The method is constructed based on the four-dimensional control volume in space-time unified domain such that the method assures to be divergence-free in the space-time unified domain and thus satisfies both the physical and geometrical conservation laws simultaneously. First of all, it is confirmed that the present method satisfies the geometric conservation law. Next, we did calculations for a single sphere settling under gravity in the stationary fluid to evaluate the present method. The method was applied to a flow around bodies driven by a flow in a square duct and the unsteady behavior of the flow is shown. The results indicate that this method is promising in such simulations.
{"title":"Trans-Mesh Method and Its Application to Simulations of Incompressible Fluid-Rigid Bodies Interaction","authors":"S. Asao, K. Matsuno, M. Yamakawa","doi":"10.1299/JCST.5.163","DOIUrl":"https://doi.org/10.1299/JCST.5.163","url":null,"abstract":"In this paper, a Trans-mesh method is presented for simulating three-dimensional incompressible fluid-rigid body interaction with collisions. In the Trans-mesh method, the bodies can move freely in a main mesh that covers the entire flow field. The method is constructed based on the four-dimensional control volume in space-time unified domain such that the method assures to be divergence-free in the space-time unified domain and thus satisfies both the physical and geometrical conservation laws simultaneously. First of all, it is confirmed that the present method satisfies the geometric conservation law. Next, we did calculations for a single sphere settling under gravity in the stationary fluid to evaluate the present method. The method was applied to a flow around bodies driven by a flow in a square duct and the unsteady behavior of the flow is shown. The results indicate that this method is promising in such simulations.","PeriodicalId":196913,"journal":{"name":"Journal of Computational Science and Technology","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116803532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In recent years, high-speed molecular detection technologies have attracted much attention and some important experimental results in this area have been reported. Tsutsui et al. successfully obtained electric signals of Au nanoparticles flowing in microchannels with gating nanoelectrodes [Tsutsui et al., Nano Lett., Vol. 9, No. 4 (2009), pp. 1659-1662]. The result of their study is expected to contribute to the fundamental development of high-speed DNA sequencers for the next generation. However, details of electro-fluid dynamics phenomena remain to be clarified. In the present study, a theoretical model is developed to explain the mechanism of the detection of charged metallic particles using gating nanoelectrodes, focusing on electric transient responses observed experimentally. The behavior of charges in the experimental system is discussed theoretically, and the resistance, capacitance, and time constant produced by the interaction between a metallic nanoparticle and the gating electrode are quantitatively evaluated. The theoretical result is in reasonable agreement with the experimental data obtained using Au nanoparticles. Thus, the present method is applicable to the study of more complex systems in which molecular fluid dynamics affects electric response.
近年来，高速分子检测技术备受关注，并在该领域取得了一些重要的实验成果。Tsutsui等人利用门控纳米电极成功地获得了金纳米颗粒在微通道中流动的电信号[Tsutsui et al.， Nano Lett]。， Vol. 9, No. 4 (2009)， pp. 1659-1662。他们的研究结果有望为下一代高速DNA测序仪的基础开发做出贡献。然而，电流体动力学现象的细节仍有待澄清。在本研究中，建立了一个理论模型来解释用门控纳米电极检测带电金属粒子的机制，重点是实验观察到的电瞬态响应。从理论上讨论了实验系统中电荷的行为，并定量评价了金属纳米粒子与门控电极相互作用产生的电阻、电容和时间常数。理论结果与实验结果基本吻合。因此，本方法适用于分子流体动力学影响电响应的更复杂系统的研究。
{"title":"Theoretical Model of Nanoparticle Detection Mechanism in Microchannel with Gating Probe Electrodes","authors":"K. Doi, M. Ueda, S. Kawano","doi":"10.1299/JCST.5.78","DOIUrl":"https://doi.org/10.1299/JCST.5.78","url":null,"abstract":"In recent years, high-speed molecular detection technologies have attracted much attention and some important experimental results in this area have been reported. Tsutsui et al. successfully obtained electric signals of Au nanoparticles flowing in microchannels with gating nanoelectrodes [Tsutsui et al., Nano Lett., Vol. 9, No. 4 (2009), pp. 1659-1662]. The result of their study is expected to contribute to the fundamental development of high-speed DNA sequencers for the next generation. However, details of electro-fluid dynamics phenomena remain to be clarified. In the present study, a theoretical model is developed to explain the mechanism of the detection of charged metallic particles using gating nanoelectrodes, focusing on electric transient responses observed experimentally. The behavior of charges in the experimental system is discussed theoretically, and the resistance, capacitance, and time constant produced by the interaction between a metallic nanoparticle and the gating electrode are quantitatively evaluated. The theoretical result is in reasonable agreement with the experimental data obtained using Au nanoparticles. Thus, the present method is applicable to the study of more complex systems in which molecular fluid dynamics affects electric response.","PeriodicalId":196913,"journal":{"name":"Journal of Computational Science and Technology","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116859677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, the influence of the discretizing method, such as a constant element or a linear element, on the accuracy of the identified results is investigated in the boundary value inverse analysis by the Boundary Element Method. For the regularization of the inverse analysis, the combination method is used; the one that the fundamental solution in B.E.M. is selected adequately and the one that the rank of the coefficient matrix is reduced. The optimum condition for solving the inverse problem is found by two performance indexes which are the condition number of the coefficient matrix and the residual norm caused by the rank reduction of the matrix. In a numerical example, the inverse problem governed by two-dimensional Laplace equation is treated. As a result, the identified result obtained using the linear element has almost the same accuracy as the one using the constant element while the accuracy using the constant element is often better, and the selection method of an adequate fundamental solution is very effective for the inverse analysis. Thus, the inverse analysis may be carried out using the constant element and the adequate fundamental solution selected.
{"title":"Influence of the Discretizing Method on the Identified Results in Boundary Value Inverse Analysis by the Boundary Element Method","authors":"S. Kawamura, K. Takao, H. Minamoto, Z. Hossain","doi":"10.1299/JCST.2.1","DOIUrl":"https://doi.org/10.1299/JCST.2.1","url":null,"abstract":"In this study, the influence of the discretizing method, such as a constant element or a linear element, on the accuracy of the identified results is investigated in the boundary value inverse analysis by the Boundary Element Method. For the regularization of the inverse analysis, the combination method is used; the one that the fundamental solution in B.E.M. is selected adequately and the one that the rank of the coefficient matrix is reduced. The optimum condition for solving the inverse problem is found by two performance indexes which are the condition number of the coefficient matrix and the residual norm caused by the rank reduction of the matrix. In a numerical example, the inverse problem governed by two-dimensional Laplace equation is treated. As a result, the identified result obtained using the linear element has almost the same accuracy as the one using the constant element while the accuracy using the constant element is often better, and the selection method of an adequate fundamental solution is very effective for the inverse analysis. Thus, the inverse analysis may be carried out using the constant element and the adequate fundamental solution selected.","PeriodicalId":196913,"journal":{"name":"Journal of Computational Science and Technology","volume":"94 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124612963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. Kogiso, Y. Hirano, S. Nishiwaki, K. Izui, M. Yoshimura, S. Min
The SLSV (single-loop-single-vector) method is modified for the reliability-based optimization problem with multiple reliability constraints. The design problem is formulated to minimize the structural volume of frame structure in terms of cross-sectional area of each frame element subjected to the two mode reliability constraints. The two mode reliability criteria consist of the mean compliance and mean eigenfrequency. The limit state functions are formulated as normalized form to achieve numerical stability of the SLSV method, because the functions are directly adopted as constraint conditions. That is a large difference from the conventional double-loop method, where the limit state functions do not appear in the optimization loop. Through numerical examples of 2-D and 3-D frame design problems, higher computational efficiency and sufficient reliability approximation accuracy by the SLSV method are demonstrated in comparison with the conventional double loop method that the mode reliabilities are evaluated by the first order reliability method (FORM) in each optimization step. Additionally, the importance of normalization of the limit state functions in the SLSV method is also demonstrated.
{"title":"Reliability-Based Topology Optimization of Frame Structures for Multiple Criteria Using SLSV Method","authors":"N. Kogiso, Y. Hirano, S. Nishiwaki, K. Izui, M. Yoshimura, S. Min","doi":"10.1299/JCST.4.172","DOIUrl":"https://doi.org/10.1299/JCST.4.172","url":null,"abstract":"The SLSV (single-loop-single-vector) method is modified for the reliability-based optimization problem with multiple reliability constraints. The design problem is formulated to minimize the structural volume of frame structure in terms of cross-sectional area of each frame element subjected to the two mode reliability constraints. The two mode reliability criteria consist of the mean compliance and mean eigenfrequency. The limit state functions are formulated as normalized form to achieve numerical stability of the SLSV method, because the functions are directly adopted as constraint conditions. That is a large difference from the conventional double-loop method, where the limit state functions do not appear in the optimization loop. Through numerical examples of 2-D and 3-D frame design problems, higher computational efficiency and sufficient reliability approximation accuracy by the SLSV method are demonstrated in comparison with the conventional double loop method that the mode reliabilities are evaluated by the first order reliability method (FORM) in each optimization step. Additionally, the importance of normalization of the limit state functions in the SLSV method is also demonstrated.","PeriodicalId":196913,"journal":{"name":"Journal of Computational Science and Technology","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125071011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The goal of this study is to develop a practical and fast simulation tool for soil-tire interaction analysis, where finite element method (FEM) and discrete element method (DEM) are coupled together, and which can be realized on a desktop PC. We have extended our formerly proposed dynamic FE-DE method (FE-DEM) to include practical soil-tire system interaction, where not only the vertical sinkage of a tire, but also the travel of a driven tire was considered. Numerical simulation by FE-DEM is stable, and the relationships between variables, such as load-sinkage and sinkage-travel distance, and the gross tractive effort and running resistance characteristics, are obtained. Moreover, the simulation result is accurate enough to predict the maximum drawbar pull for a given tire, once the appropriate parameter values are provided. Therefore, the developed FE-DEM program can be applied with sufficient accuracy to interaction problems in soil-tire systems.
{"title":"Analysis of Tire Tractive Performance on Deformable Terrain by Finite Element-Discrete Element Method","authors":"H. Nakashima, Yuzuru Takatsu","doi":"10.1299/JCST.2.423","DOIUrl":"https://doi.org/10.1299/JCST.2.423","url":null,"abstract":"The goal of this study is to develop a practical and fast simulation tool for soil-tire interaction analysis, where finite element method (FEM) and discrete element method (DEM) are coupled together, and which can be realized on a desktop PC. We have extended our formerly proposed dynamic FE-DE method (FE-DEM) to include practical soil-tire system interaction, where not only the vertical sinkage of a tire, but also the travel of a driven tire was considered. Numerical simulation by FE-DEM is stable, and the relationships between variables, such as load-sinkage and sinkage-travel distance, and the gross tractive effort and running resistance characteristics, are obtained. Moreover, the simulation result is accurate enough to predict the maximum drawbar pull for a given tire, once the appropriate parameter values are provided. Therefore, the developed FE-DEM program can be applied with sufficient accuracy to interaction problems in soil-tire systems.","PeriodicalId":196913,"journal":{"name":"Journal of Computational Science and Technology","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129205846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hwisim Hwang, Y. Uetsuji, S. Sakata, K. Tsuchiya, E. Nakamachi
A process crystallography algorithm based on the first-principles aided triple-scale analysis is newly developed to design biocompatible piezoelectric thin films fabricated on a substrate. The pseudo-potential method within the density functional theory was used to predict the crystal morphology of thin film, such as preferred orientations and their fractions as well as the structural stability of possible conformations of crystal clusters on substrates. A crystal morphology at the micro scale was selected and macro homogenized properties of piezoelectric thin film were obtained through a double-scale finite element analysis based on the crystallographic homogenization theory. Further, our analysis was applied to the existent biocompatible piezoelectric BaTiO3 thin films, fabricated on SrTiO3(110), SrTiO3(001) and MgO(100) substrates. Numerical results of the preferred orientations of the micro structure and the homogenized dielectric constants of the macro structure showed good agreements with experimental results. Additionally, the proposed process crystallography algorithm was applied to the new biocompatible piezoelectric MgSiO3 thin film generation, which has been found by the first-principles calculation in the previous study. As a result, the computational result indicates that the Cr(110) substrate is most suitable for stable crystal growth of [101] oriented MgSiO3 and shows high piezoelectric stress constants, such as e33= 5.39 C/m2 and e31= -3.64 C/m2.
{"title":"Proposition of a First-Principles Aided Triple-Scale Analysis for Biocompatible Piezoelectric Thin Films","authors":"Hwisim Hwang, Y. Uetsuji, S. Sakata, K. Tsuchiya, E. Nakamachi","doi":"10.1299/JCST.3.499","DOIUrl":"https://doi.org/10.1299/JCST.3.499","url":null,"abstract":"A process crystallography algorithm based on the first-principles aided triple-scale analysis is newly developed to design biocompatible piezoelectric thin films fabricated on a substrate. The pseudo-potential method within the density functional theory was used to predict the crystal morphology of thin film, such as preferred orientations and their fractions as well as the structural stability of possible conformations of crystal clusters on substrates. A crystal morphology at the micro scale was selected and macro homogenized properties of piezoelectric thin film were obtained through a double-scale finite element analysis based on the crystallographic homogenization theory. Further, our analysis was applied to the existent biocompatible piezoelectric BaTiO3 thin films, fabricated on SrTiO3(110), SrTiO3(001) and MgO(100) substrates. Numerical results of the preferred orientations of the micro structure and the homogenized dielectric constants of the macro structure showed good agreements with experimental results. Additionally, the proposed process crystallography algorithm was applied to the new biocompatible piezoelectric MgSiO3 thin film generation, which has been found by the first-principles calculation in the previous study. As a result, the computational result indicates that the Cr(110) substrate is most suitable for stable crystal growth of [101] oriented MgSiO3 and shows high piezoelectric stress constants, such as e33= 5.39 C/m2 and e31= -3.64 C/m2.","PeriodicalId":196913,"journal":{"name":"Journal of Computational Science and Technology","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126720075","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Miresmaeili, N. Saintier, H. Notsu, J. Olive, H. Kanayama
Many attempts were made in the past to investigate numerically the metal-hydrogen interactions at macro-scale but the actual microstructure was generally not introduced into the analyses. The objective of this work is to simulate, on an artificial polycrystal, the effect of the microstructure-induced stress-strain field heterogeneity on the internal hydrogen evolution. Finite element method is used to take into account explicitly the grain morphologies and their crystalline orientations into the description of the mechanical deformation. A one-way coupled crystal plasticity-transient hydrogen diffusion analysis is developed and applied to solve the boundary value problem. The analysis of the computed hydrogen content field shows that a segregation of hydrogen is observed mainly at the grain boundaries. It is also shown that grain size has a significant effect not only on the amount of hydrogen segregated at the grain boundaries but also on the relative size of concentration gradients.
{"title":"One-Way Coupled Crystal Plasticity-Hydrogen Diffusion Simulation on Artificial Microstructure","authors":"R. Miresmaeili, N. Saintier, H. Notsu, J. Olive, H. Kanayama","doi":"10.1299/JCST.4.105","DOIUrl":"https://doi.org/10.1299/JCST.4.105","url":null,"abstract":"Many attempts were made in the past to investigate numerically the metal-hydrogen interactions at macro-scale but the actual microstructure was generally not introduced into the analyses. The objective of this work is to simulate, on an artificial polycrystal, the effect of the microstructure-induced stress-strain field heterogeneity on the internal hydrogen evolution. Finite element method is used to take into account explicitly the grain morphologies and their crystalline orientations into the description of the mechanical deformation. A one-way coupled crystal plasticity-transient hydrogen diffusion analysis is developed and applied to solve the boundary value problem. The analysis of the computed hydrogen content field shows that a segregation of hydrogen is observed mainly at the grain boundaries. It is also shown that grain size has a significant effect not only on the amount of hydrogen segregated at the grain boundaries but also on the relative size of concentration gradients.","PeriodicalId":196913,"journal":{"name":"Journal of Computational Science and Technology","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121296662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：