Active fiber composites (AFC) are comprised of lead zirconate titanate (PZT) fibers embedded in a polymer. This paper presents an experimental characterization of the PZT fibers and a constitutive model focused on their time-dependent, nonlinear response. The experiments herein focus on characterizing time dependence of various properties by conducting creep, relaxation, mechanical and electric field-cyclic loading at different frequencies. The constitutive model is a time-dependent polarization model that predicts nonlinear polarization and electro-mechanical strain responses of the fibers. The model of PZT fibers is used in the FEM simulation of AFCs and results of the model are compared to experiments for validation.
{"title":"Characterization and modeling time-dependent behavior in PZT fibers and active fiber composites","authors":"M. Dridi, H. B. Atitallah, Z. Ounaies, A. Muliana","doi":"10.1117/12.2084811","DOIUrl":"https://doi.org/10.1117/12.2084811","url":null,"abstract":"Active fiber composites (AFC) are comprised of lead zirconate titanate (PZT) fibers embedded in a polymer. This paper presents an experimental characterization of the PZT fibers and a constitutive model focused on their time-dependent, nonlinear response. The experiments herein focus on characterizing time dependence of various properties by conducting creep, relaxation, mechanical and electric field-cyclic loading at different frequencies. The constitutive model is a time-dependent polarization model that predicts nonlinear polarization and electro-mechanical strain responses of the fibers. The model of PZT fibers is used in the FEM simulation of AFCs and results of the model are compared to experiments for validation.","PeriodicalId":51155,"journal":{"name":"Smart Structures and Systems","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2015-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78960637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A new energy harvester, based on the fluttering phenomenon, is presented. The device is done with a wing connected to a support via two elastomers. When a fluid in motion impinges on this elastic structure, an amount of kinetic energy is transferred to the system, inducing large amplitude oscillations if few mechanical parameters are correctly set. In order to transform the mechanical energy in electrical energy, an electromagnetic coupling is adopted. In this way, it is possible to produce several mW in a wind of 4 m/s with a centimeter-sized device. The device is conceived as an autonomous power source for distributed sensors to be used in Internet of Things.
{"title":"A new energy harvester for fluids in motion","authors":"C. Boragno, G. Boccalero","doi":"10.1117/12.2084591","DOIUrl":"https://doi.org/10.1117/12.2084591","url":null,"abstract":"A new energy harvester, based on the fluttering phenomenon, is presented. The device is done with a wing connected to a support via two elastomers. When a fluid in motion impinges on this elastic structure, an amount of kinetic energy is transferred to the system, inducing large amplitude oscillations if few mechanical parameters are correctly set. In order to transform the mechanical energy in electrical energy, an electromagnetic coupling is adopted. In this way, it is possible to produce several mW in a wind of 4 m/s with a centimeter-sized device. The device is conceived as an autonomous power source for distributed sensors to be used in Internet of Things.","PeriodicalId":51155,"journal":{"name":"Smart Structures and Systems","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2015-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82822332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, we investigate the feasibility of energy harvesting from axisymmetric vibrations of annular ionic polymer metal composites (IPMCs). We consider an in-house fabricated IPMC that is clamped at its inner radius to a moving base and is free at its outer radius. We propose a physics-based model for energy harvesting from underwater vibrations, in which the IPMC is described as a thin annular plate undergoing axisymmetric vibrations with an added mass due to the encompassing fluid. Experiments are performed to elucidate the effect of the shunting resistance and the excitation frequency on energy harvesting.
{"title":"Underwater energy harvesting from vibrations of annular ionic polymer metal composites","authors":"Youngsu Cha, Shervin Abdolhamidi, M. Porfiri","doi":"10.1117/12.2083648","DOIUrl":"https://doi.org/10.1117/12.2083648","url":null,"abstract":"In this paper, we investigate the feasibility of energy harvesting from axisymmetric vibrations of annular ionic polymer metal composites (IPMCs). We consider an in-house fabricated IPMC that is clamped at its inner radius to a moving base and is free at its outer radius. We propose a physics-based model for energy harvesting from underwater vibrations, in which the IPMC is described as a thin annular plate undergoing axisymmetric vibrations with an added mass due to the encompassing fluid. Experiments are performed to elucidate the effect of the shunting resistance and the excitation frequency on energy harvesting.","PeriodicalId":51155,"journal":{"name":"Smart Structures and Systems","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2015-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89289124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work, a new type of MR brake featuring tapered inner magnetic core is proposed and its braking performance is numerically evaluated. In order to achieve high braking torque with restricted size and weight of MR brake system, tapered inner magnetic core is designed and expands the area that the magnetic flux is passing by MR fluid-filled gap. The mathematical braking torque model of the proposed MR brake is derived based on the field-dependent Bingham rheological model of MR fluid. Finite element analysis is carried out to identify electromagnetic characteristics of the conventional and the proposed MR brake configuration. To demonstrate the superiority of the proposed MR brake, the braking torque of the proposed MR brake is numerically evaluated and compared with that of conventional MR brake model.
{"title":"Design of MR brake featuring tapered inner magnetic core","authors":"J. Sohn, J. Oh, Seung-bok Choi","doi":"10.1117/12.2084137","DOIUrl":"https://doi.org/10.1117/12.2084137","url":null,"abstract":"In this work, a new type of MR brake featuring tapered inner magnetic core is proposed and its braking performance is numerically evaluated. In order to achieve high braking torque with restricted size and weight of MR brake system, tapered inner magnetic core is designed and expands the area that the magnetic flux is passing by MR fluid-filled gap. The mathematical braking torque model of the proposed MR brake is derived based on the field-dependent Bingham rheological model of MR fluid. Finite element analysis is carried out to identify electromagnetic characteristics of the conventional and the proposed MR brake configuration. To demonstrate the superiority of the proposed MR brake, the braking torque of the proposed MR brake is numerically evaluated and compared with that of conventional MR brake model.","PeriodicalId":51155,"journal":{"name":"Smart Structures and Systems","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2015-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91079419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
One of the important parameters in the design of transmission lines is the evaluation of the susceptibility of these cables to vibrations and if necessary, providing proper means to mitigate these vibrations. Transmission lines are especially susceptible to vibrations as a result of their light weight. Viscous dampers are one of the tools that can be applied to mitigate cable vibrations. However, the damping ratio obtained by these dampers is very limited. The present study provides a finite element formulation for an isoparametric cable element. A comparison is made between the results of presented approach with finite series method to validate the model. Additionally, a comparison is made between linear and non-linear behavior of a cable under sweep sinusoidal excitations with different amplitudes. Finally, a case study is conducted to investigate the potential of additional damping provided by a third viscous damper for the case in which two rubber bushings are already attached to the cable near the anchorages. Based on this case study, the dependency between the third damper location and optimum viscosity for maximum vibration mitigation that can be given to a cable with rubber bushings is investigated. The results of the present study show that although rubber bushings may help mitigating vibrations, they reduce the effect of additional damping devices. Additionally, for non-sagged cables, the nonlinearity is negligible in moderate vibrations. Lastly, if the third damper viscosity is selected properly, it can be very effective in further mitigating the vibrations amplitudes.
{"title":"Potential of viscous dampers for vibration mitigation of transmission overhead lines","authors":"A. Bassam, A. Soltani","doi":"10.1117/12.2083666","DOIUrl":"https://doi.org/10.1117/12.2083666","url":null,"abstract":"One of the important parameters in the design of transmission lines is the evaluation of the susceptibility of these cables to vibrations and if necessary, providing proper means to mitigate these vibrations. Transmission lines are especially susceptible to vibrations as a result of their light weight. Viscous dampers are one of the tools that can be applied to mitigate cable vibrations. However, the damping ratio obtained by these dampers is very limited. The present study provides a finite element formulation for an isoparametric cable element. A comparison is made between the results of presented approach with finite series method to validate the model. Additionally, a comparison is made between linear and non-linear behavior of a cable under sweep sinusoidal excitations with different amplitudes. Finally, a case study is conducted to investigate the potential of additional damping provided by a third viscous damper for the case in which two rubber bushings are already attached to the cable near the anchorages. Based on this case study, the dependency between the third damper location and optimum viscosity for maximum vibration mitigation that can be given to a cable with rubber bushings is investigated. The results of the present study show that although rubber bushings may help mitigating vibrations, they reduce the effect of additional damping devices. Additionally, for non-sagged cables, the nonlinearity is negligible in moderate vibrations. Lastly, if the third damper viscosity is selected properly, it can be very effective in further mitigating the vibrations amplitudes.","PeriodicalId":51155,"journal":{"name":"Smart Structures and Systems","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2015-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84920697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Soomin Kim, Pyunghwa Kim, Seung-hyun Choi, J. Oh, Seung-bok Choi
In the field of medicine, several new areas have been currently introduced such as robot-assisted surgery. However, the major drawback of these systems is that there is no tactile communication between doctors and surgical sites. When the tactile system is brought up, telemedicine including telerobotic surgery can be enhanced much more than now. In this study, a new tactile device is designed using a single magnetorhological (MR) sponge cell to realize the sensation of human organs. MR fluids and an open celled polyurethane foam are used to propose the MR sponge cell. The viscous and elastic sensational behaviors of human organs are realized by the MR sponge cell. Before developing the tactile device, tactile sensation according to touch of human fingers are quantified in advance. The finger is then treated as a reduced beam bundle model (BBM) in which the fingertip is comprised of an elastic beam virtually. Under the reduced BBM, when people want to sense an object, the fingertip is investigated by pushing and sliding. Accordingly, while several magnitudes of magnetic fields are applied to the tactile device, normal and tangential reaction forces and bending moment are measured by 6-axis force/torque sensor instead of the fingertip. These measured data are used to compare with soft tissues. It is demonstrated that the proposed MR sponge cell can realize any part of the organ based on the obtained data.
{"title":"Tactile device utilizing a single magnetorheological sponge: experimental investigation","authors":"Soomin Kim, Pyunghwa Kim, Seung-hyun Choi, J. Oh, Seung-bok Choi","doi":"10.1117/12.2083749","DOIUrl":"https://doi.org/10.1117/12.2083749","url":null,"abstract":"In the field of medicine, several new areas have been currently introduced such as robot-assisted surgery. However, the major drawback of these systems is that there is no tactile communication between doctors and surgical sites. When the tactile system is brought up, telemedicine including telerobotic surgery can be enhanced much more than now. In this study, a new tactile device is designed using a single magnetorhological (MR) sponge cell to realize the sensation of human organs. MR fluids and an open celled polyurethane foam are used to propose the MR sponge cell. The viscous and elastic sensational behaviors of human organs are realized by the MR sponge cell. Before developing the tactile device, tactile sensation according to touch of human fingers are quantified in advance. The finger is then treated as a reduced beam bundle model (BBM) in which the fingertip is comprised of an elastic beam virtually. Under the reduced BBM, when people want to sense an object, the fingertip is investigated by pushing and sliding. Accordingly, while several magnitudes of magnetic fields are applied to the tactile device, normal and tangential reaction forces and bending moment are measured by 6-axis force/torque sensor instead of the fingertip. These measured data are used to compare with soft tissues. It is demonstrated that the proposed MR sponge cell can realize any part of the organ based on the obtained data.","PeriodicalId":51155,"journal":{"name":"Smart Structures and Systems","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2015-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85060065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A prosthetic knee for above-knee (AK) amputees is categorized into two types; namely a passive and an active type. The passive prosthetic knee is generally made by elastic materials such as carbon fiber reinforced composite material, titanium and etc. The passive prosthetic knee easy to walk. But, it has disadvantages such that a knee joint motion is not similar to ordinary people. On the other hand, the active prosthetic knee can control the knee joint angle effectively because of mechanical actuator and microprocessor. The actuator should generate large damping force to support the weight of human body. But, generating the large torque using small actuator is difficult. To solve this problem, a semi-active type prosthetic knee has been researched. This paper proposes a semi-active prosthetic knee using a flow mode magneto-rheological (MR) damper for AK amputees. The proposed semi-active type prosthetic knee consists of the flow mode MR damper, hinge and prosthetic knee body. In order to support weight of human body, the required energy of MR damper is smaller than actuator of active prosthetic leg. And it can control the knee joint angle by inducing the magnetic field during the stance phase.
{"title":"A prosthetic knee using magnetorhelogical fluid damper for above-knee amputees","authors":"Jinhyuk Park, Seung-bok Choi","doi":"10.1117/12.2083753","DOIUrl":"https://doi.org/10.1117/12.2083753","url":null,"abstract":"A prosthetic knee for above-knee (AK) amputees is categorized into two types; namely a passive and an active type. The passive prosthetic knee is generally made by elastic materials such as carbon fiber reinforced composite material, titanium and etc. The passive prosthetic knee easy to walk. But, it has disadvantages such that a knee joint motion is not similar to ordinary people. On the other hand, the active prosthetic knee can control the knee joint angle effectively because of mechanical actuator and microprocessor. The actuator should generate large damping force to support the weight of human body. But, generating the large torque using small actuator is difficult. To solve this problem, a semi-active type prosthetic knee has been researched. This paper proposes a semi-active prosthetic knee using a flow mode magneto-rheological (MR) damper for AK amputees. The proposed semi-active type prosthetic knee consists of the flow mode MR damper, hinge and prosthetic knee body. In order to support weight of human body, the required energy of MR damper is smaller than actuator of active prosthetic leg. And it can control the knee joint angle by inducing the magnetic field during the stance phase.","PeriodicalId":51155,"journal":{"name":"Smart Structures and Systems","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2015-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79754646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A piezofan is a resonant device that uses a piezoceramic material to induce oscillations in a cantilever beam. In this study, lumped-mass modelling is used to analyze a piezoelectric fan. Uncertainties are associated with the piezoelectric structures due to several reasons such as variation during manufacturing process, temperature, presence of adhesive layer between the piezoelectric actuator/sensor and the shim stock etc. Presence of uncertainty in the piezoelectric materials can influence the dynamic behavior of the piezoelectric fan such as natural frequency, tip deflection etc. Moreover, these quantities will also affect the performance parameters of the piezoelectric fan. Uncertainty analysis is performed using classical Monte Carlo Simulation (MCS). It is found that the propagation of uncertainty causes significant deviations from the baseline deterministic predictions, which also affect the achievable performance of the piezofan. The numerical results in this paper provide useful bounds on several performance parameters of the cooling fan and will enhance confidence in the design process.
{"title":"Effect of material uncertainties on dynamic analysis of piezoelectric fans","authors":"S. Srivastava, S. Yadav, S. Mukherjee","doi":"10.1117/12.2083012","DOIUrl":"https://doi.org/10.1117/12.2083012","url":null,"abstract":"A piezofan is a resonant device that uses a piezoceramic material to induce oscillations in a cantilever beam. In this study, lumped-mass modelling is used to analyze a piezoelectric fan. Uncertainties are associated with the piezoelectric structures due to several reasons such as variation during manufacturing process, temperature, presence of adhesive layer between the piezoelectric actuator/sensor and the shim stock etc. Presence of uncertainty in the piezoelectric materials can influence the dynamic behavior of the piezoelectric fan such as natural frequency, tip deflection etc. Moreover, these quantities will also affect the performance parameters of the piezoelectric fan. Uncertainty analysis is performed using classical Monte Carlo Simulation (MCS). It is found that the propagation of uncertainty causes significant deviations from the baseline deterministic predictions, which also affect the achievable performance of the piezofan. The numerical results in this paper provide useful bounds on several performance parameters of the cooling fan and will enhance confidence in the design process.","PeriodicalId":51155,"journal":{"name":"Smart Structures and Systems","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2015-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80456432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Recently, the concept of developing an active steerable needle has gathered a lot of attention as they could potentially result in an improved outcome in various medical percutaneous procedures. Compared to the conventional straight bevel tip needles, active needles can be bent by means of the attached actuation component in order to reach the target locations more accurately. In this study, the movement of the passive needle inside the tissue was investigated using numerical and experimental approaches. A finite element simulation of needle insertion was developed using LSDYNA software to study the maneuverability of the passive needle. The Arbitrary-Eulerian-Lagrangian (ALE) formulation was used to model the interactions between the solid elements of the needle and the fluid elements of the tissue. Also the passive needle insertion tests were performed inside a tissue mimicking phantom. This model was validated for the 150mm of insertion which is similar to the depth in our needle insertion experiments. The model is intended to be based as a framework for modeling the active needle insertion in future.
{"title":"Simulation and experimental studies of the SMA-activated needle behavior inside the tissue","authors":"B. Konh, M. Honarvar, P. Hutapea","doi":"10.1117/12.2084287","DOIUrl":"https://doi.org/10.1117/12.2084287","url":null,"abstract":"Recently, the concept of developing an active steerable needle has gathered a lot of attention as they could potentially result in an improved outcome in various medical percutaneous procedures. Compared to the conventional straight bevel tip needles, active needles can be bent by means of the attached actuation component in order to reach the target locations more accurately. In this study, the movement of the passive needle inside the tissue was investigated using numerical and experimental approaches. A finite element simulation of needle insertion was developed using LSDYNA software to study the maneuverability of the passive needle. The Arbitrary-Eulerian-Lagrangian (ALE) formulation was used to model the interactions between the solid elements of the needle and the fluid elements of the tissue. Also the passive needle insertion tests were performed inside a tissue mimicking phantom. This model was validated for the 150mm of insertion which is similar to the depth in our needle insertion experiments. The model is intended to be based as a framework for modeling the active needle insertion in future.","PeriodicalId":51155,"journal":{"name":"Smart Structures and Systems","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2015-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80474970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, a new innovative modified high-loaded magneto-rheological fluid (MR in short) damper-mount is presented. The proposed damper-mount is designed based on two modes of MR fluid such as flow mode and shear mode, and it includes two separated electric coil for establishing magnetic field. The damping force of the damper-mount is analyzed based on the difference pressure between upper chamber and lower chamber. After analyzing the mathematical function of damping force, the proposed mount is optimized following the maximal damping force by using ANSYS software. Besides, there is a laboratorial MR fluid using in this optimization such as plate-like fluid MRF140. Results of optimization show that the requirement of damping force is obtain and the saturation of materials is in range of limitation.
{"title":"Design and analysis of an innovative combined magneto-rheological damper-mount","authors":"D. Phu, Jye Ung Chung, Seung-bok Choi","doi":"10.1117/12.2083810","DOIUrl":"https://doi.org/10.1117/12.2083810","url":null,"abstract":"In this paper, a new innovative modified high-loaded magneto-rheological fluid (MR in short) damper-mount is presented. The proposed damper-mount is designed based on two modes of MR fluid such as flow mode and shear mode, and it includes two separated electric coil for establishing magnetic field. The damping force of the damper-mount is analyzed based on the difference pressure between upper chamber and lower chamber. After analyzing the mathematical function of damping force, the proposed mount is optimized following the maximal damping force by using ANSYS software. Besides, there is a laboratorial MR fluid using in this optimization such as plate-like fluid MRF140. Results of optimization show that the requirement of damping force is obtain and the saturation of materials is in range of limitation.","PeriodicalId":51155,"journal":{"name":"Smart Structures and Systems","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2015-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88186802","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","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：