Pub Date : 2006-04-24DOI: 10.1109/ESIME.2006.1643995
A. Tay, Hua Li, Xiangyang Gao, J. Chen, V. Kripesh
Fluidic self-assembly processes have been recently demonstrated to be a feasible method of assembling tiny chips in a cost-effective manner. In order to successfully implement the fluidic self-assembly process, it is important to quantify the magnitudes of the restoring capillary force and torque between the chip and the binding site and to determine the fluid dynamic forces acting on the chip as fluid flows over the chip. This paper presents results of numerical simulations of these restoring capillary forces and torques, and discusses the effect of various parameters on them, such as lubricant volume, component orientation and contact angle. The results show that the restoring forces in both lift and shift directions decrease significantly with the volume of lubricant. Analysis of the sensitivity of the restoring torque to the contact angle between the lubricant and the self-assembled monolayer (SAM) in water is also carried out. It is observed that, at smaller contact angles, the maximum torque is insensitive to the contact angle between 0 to 40deg. It thus suggests that a lubricant with a contact angle less than 40 degrees can be used without loss of effectiveness. The equilibrium of the chip under the action of flow-induced and capillary forces has also been analysed
{"title":"Numerical Simulation of Capillary and Fluid Dynamic Forces on Tiny Chips in Fluidic Self-Assembly Process","authors":"A. Tay, Hua Li, Xiangyang Gao, J. Chen, V. Kripesh","doi":"10.1109/ESIME.2006.1643995","DOIUrl":"https://doi.org/10.1109/ESIME.2006.1643995","url":null,"abstract":"Fluidic self-assembly processes have been recently demonstrated to be a feasible method of assembling tiny chips in a cost-effective manner. In order to successfully implement the fluidic self-assembly process, it is important to quantify the magnitudes of the restoring capillary force and torque between the chip and the binding site and to determine the fluid dynamic forces acting on the chip as fluid flows over the chip. This paper presents results of numerical simulations of these restoring capillary forces and torques, and discusses the effect of various parameters on them, such as lubricant volume, component orientation and contact angle. The results show that the restoring forces in both lift and shift directions decrease significantly with the volume of lubricant. Analysis of the sensitivity of the restoring torque to the contact angle between the lubricant and the self-assembled monolayer (SAM) in water is also carried out. It is observed that, at smaller contact angles, the maximum torque is insensitive to the contact angle between 0 to 40deg. It thus suggests that a lubricant with a contact angle less than 40 degrees can be used without loss of effectiveness. The equilibrium of the chip under the action of flow-induced and capillary forces has also been analysed","PeriodicalId":60796,"journal":{"name":"微纳电子与智能制造","volume":"20 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2006-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86419429","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}
Pub Date : 2006-04-24DOI: 10.1109/ESIME.2006.1643950
Y. Lai, T. Wang, Chang-Chi Lee, Hsuan-Yu Chen
In this paper, we evaluate the board-level thermal performance of QFP with an unattached drop-in heat spreader numerically and experimentally. The die is given a power dissipation and induced thermomechanical deformations and the gap distribution on the unattached interface are calculated through the three-dimensional thermal-mechanical coupling analysis incorporated with the contact methodology. The measured junction to ambient thermal resistance is used to validate the numerical results, which involve different interfacial thermal transfer conditions
{"title":"Numerical Examination and Experimental Verification of Thermal Performance of Board-level QFP with Unattached Drop-in Heat Spreader","authors":"Y. Lai, T. Wang, Chang-Chi Lee, Hsuan-Yu Chen","doi":"10.1109/ESIME.2006.1643950","DOIUrl":"https://doi.org/10.1109/ESIME.2006.1643950","url":null,"abstract":"In this paper, we evaluate the board-level thermal performance of QFP with an unattached drop-in heat spreader numerically and experimentally. The die is given a power dissipation and induced thermomechanical deformations and the gap distribution on the unattached interface are calculated through the three-dimensional thermal-mechanical coupling analysis incorporated with the contact methodology. The measured junction to ambient thermal resistance is used to validate the numerical results, which involve different interfacial thermal transfer conditions","PeriodicalId":60796,"journal":{"name":"微纳电子与智能制造","volume":"24 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2006-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87689374","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}
Pub Date : 2006-04-24DOI: 10.1109/ESIME.2006.1644035
M. Damnjanović, G. Stojanović, L. Zivanov
In this paper, modeling and simulation of electrical characteristics of EMI suppressors will be presented. Ferrite and varistor EMI suppressors consist of conductive layers embedded in ferrite or varistor monolithic structure, which make them very suitable for elimination of conducted EMI. In this paper software tool for calculation of electrical characteristics of ferrite and varistor EMI suppressor is given. A scalable analytical model of different EMI suppressor structures suitable for design and circuit simulations is presented. By using our algorithm, we are able to predict correctly all variations of electrical characteristics introduced by varying geometry parameters of EMI suppressor. These integrated passive devices were tested in the frequency range 1MHz-3GHz using an Agilent 4287A RF LCR meter. The measurements confirm the validity of the analytical model
{"title":"Modeling and Simulation of Ferrite and Varistor EMI Suppressors","authors":"M. Damnjanović, G. Stojanović, L. Zivanov","doi":"10.1109/ESIME.2006.1644035","DOIUrl":"https://doi.org/10.1109/ESIME.2006.1644035","url":null,"abstract":"In this paper, modeling and simulation of electrical characteristics of EMI suppressors will be presented. Ferrite and varistor EMI suppressors consist of conductive layers embedded in ferrite or varistor monolithic structure, which make them very suitable for elimination of conducted EMI. In this paper software tool for calculation of electrical characteristics of ferrite and varistor EMI suppressor is given. A scalable analytical model of different EMI suppressor structures suitable for design and circuit simulations is presented. By using our algorithm, we are able to predict correctly all variations of electrical characteristics introduced by varying geometry parameters of EMI suppressor. These integrated passive devices were tested in the frequency range 1MHz-3GHz using an Agilent 4287A RF LCR meter. The measurements confirm the validity of the analytical model","PeriodicalId":60796,"journal":{"name":"微纳电子与智能制造","volume":"59 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2006-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87215309","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}
Pub Date : 2006-04-24DOI: 10.1109/ESIME.2006.1643944
S.T. Wang, Mei-Hui Chung, Chunlei Yu
Surface transverse waves (STW) resonators exhibit substantial advantages over conventional surface acoustic wave (SAW) resonators. They demonstrate higher operating frequencies, better temperature stability, higher intrinsic material quality, and etc. In this work, two low loss and high quality factor STW resonators with center frequencies at 622MHz and 1244MHz for SONET/SDH were uniquely designed and fabricated on quartz substrate. The insertion loss of the devices was as low as 3dB, loaded quality factor was as high as 1600, and sidelobe suppression reached 30dB. The temperature behavior of these two resonators were also presented by experiment with turnover temperatures at about 50degC for 622MHz and 20degC for 1244MHz, repectively
{"title":"Design of High Performance Surface Transverse Waver Resonators","authors":"S.T. Wang, Mei-Hui Chung, Chunlei Yu","doi":"10.1109/ESIME.2006.1643944","DOIUrl":"https://doi.org/10.1109/ESIME.2006.1643944","url":null,"abstract":"Surface transverse waves (STW) resonators exhibit substantial advantages over conventional surface acoustic wave (SAW) resonators. They demonstrate higher operating frequencies, better temperature stability, higher intrinsic material quality, and etc. In this work, two low loss and high quality factor STW resonators with center frequencies at 622MHz and 1244MHz for SONET/SDH were uniquely designed and fabricated on quartz substrate. The insertion loss of the devices was as low as 3dB, loaded quality factor was as high as 1600, and sidelobe suppression reached 30dB. The temperature behavior of these two resonators were also presented by experiment with turnover temperatures at about 50degC for 622MHz and 20degC for 1244MHz, repectively","PeriodicalId":60796,"journal":{"name":"微纳电子与智能制造","volume":"44 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2006-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77065250","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}
Pub Date : 2006-04-24DOI: 10.1109/ESIME.2006.1643971
A. Pandolfi, M. Ortiz
We present a new design of PDMS microvalves based on bistable configuration of the separation membrane. PDMS elastomers are sensitive to several chemical solvents, which induce changes in the mechanical properties and swelling of the material. By using a soft rubber constitutive model, we numerically analyze the performance of new design of microvalves and microfluidic systems, able to reduce the magnitude of the activation pressure and the duration of the activation time
{"title":"Modeling New Design of Fluidic Microvalves","authors":"A. Pandolfi, M. Ortiz","doi":"10.1109/ESIME.2006.1643971","DOIUrl":"https://doi.org/10.1109/ESIME.2006.1643971","url":null,"abstract":"We present a new design of PDMS microvalves based on bistable configuration of the separation membrane. PDMS elastomers are sensitive to several chemical solvents, which induce changes in the mechanical properties and swelling of the material. By using a soft rubber constitutive model, we numerically analyze the performance of new design of microvalves and microfluidic systems, able to reduce the magnitude of the activation pressure and the duration of the activation time","PeriodicalId":60796,"journal":{"name":"微纳电子与智能制造","volume":"142 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2006-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77467350","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}
Pub Date : 2006-04-24DOI: 10.1109/ESIME.2006.1643943
L. Del Tin, R. Gaddi, A. Gnudi, E. Rudnyi, A. Greiner, J. Korvink
A simulation methodology to reduce computational time of pre-stressed harmonic analysis of radio frequency (RF) microresonators is demonstrated. The methodology is based on the application of model order reduction to a system of ordinary differential equations obtained after spatial discretization by finite element software. Model order reduction produces a low dimensional approximation of the original system and hence enables a substantial reduction of simulation time while maintaining a very small approximation error. The approach allows performing rapid device design and optimization. Once the device design and working conditions have been defined its reduced model can also be used to implement a behavioural model that can be employed in system level simulations
{"title":"Efficient Pre-stressed Harmonic Analysis of RF-Microresonators by Means of Model Order Reduction","authors":"L. Del Tin, R. Gaddi, A. Gnudi, E. Rudnyi, A. Greiner, J. Korvink","doi":"10.1109/ESIME.2006.1643943","DOIUrl":"https://doi.org/10.1109/ESIME.2006.1643943","url":null,"abstract":"A simulation methodology to reduce computational time of pre-stressed harmonic analysis of radio frequency (RF) microresonators is demonstrated. The methodology is based on the application of model order reduction to a system of ordinary differential equations obtained after spatial discretization by finite element software. Model order reduction produces a low dimensional approximation of the original system and hence enables a substantial reduction of simulation time while maintaining a very small approximation error. The approach allows performing rapid device design and optimization. Once the device design and working conditions have been defined its reduced model can also be used to implement a behavioural model that can be employed in system level simulations","PeriodicalId":60796,"journal":{"name":"微纳电子与智能制造","volume":"30 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2006-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76515822","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}
Pub Date : 2006-04-24DOI: 10.1109/ESIME.2006.1643999
T. Hauck, G. Li, A. McNeill, H. Knoll, M. Ebert, J. Bagdahn
Drop testing of micromachined accelerometers from the height of a table top to a solid surface shows that a moderate impact can result in severe damage of transducer elements. The relative high stiffness of the accelerometer device in combination with a high contact stiffness of the solid surface cause extremely high acceleration pulses at the impact. This paper presents a detailed analysis of the consequences of dropping a micromachined transducer structure to a solid surface. The analysis is composed of experimental testing and numerical simulation. Impact forces are measured for bare sensor chips and molded sensor devices by means of an instrumented drop test. Structural simulation models are generated for micromachined transducers. These models consider the dynamics of the deformation behavior of moveable elements including a travel stop and associated possible impact inside the sensor element. Maximum stresses are calculated in critical regions of the transducer. Weibull theory and statistical distributions of material strength are considered in order to predict the probability for crack initiation due to stress concentrations
{"title":"Drop Simulation and Stress Analysis of MEMS Devices","authors":"T. Hauck, G. Li, A. McNeill, H. Knoll, M. Ebert, J. Bagdahn","doi":"10.1109/ESIME.2006.1643999","DOIUrl":"https://doi.org/10.1109/ESIME.2006.1643999","url":null,"abstract":"Drop testing of micromachined accelerometers from the height of a table top to a solid surface shows that a moderate impact can result in severe damage of transducer elements. The relative high stiffness of the accelerometer device in combination with a high contact stiffness of the solid surface cause extremely high acceleration pulses at the impact. This paper presents a detailed analysis of the consequences of dropping a micromachined transducer structure to a solid surface. The analysis is composed of experimental testing and numerical simulation. Impact forces are measured for bare sensor chips and molded sensor devices by means of an instrumented drop test. Structural simulation models are generated for micromachined transducers. These models consider the dynamics of the deformation behavior of moveable elements including a travel stop and associated possible impact inside the sensor element. Maximum stresses are calculated in critical regions of the transducer. Weibull theory and statistical distributions of material strength are considered in order to predict the probability for crack initiation due to stress concentrations","PeriodicalId":60796,"journal":{"name":"微纳电子与智能制造","volume":"34 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2006-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74383717","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}
Pub Date : 2006-04-24DOI: 10.1109/ESIME.2006.1643959
M. Boutaayamou, K. H. Nair, R. Sabariego, P. Dular
The numerical models describing the behaviour of electrostatically actuated microsystems often disregard fringing fields. However, taking the fringing fields into account is crucial for an accurate computation of the electrostatic forces. In this work, the finite element method is applied for modeling electrostatic actuators. The electrostatic force distribution is obtained by locally applying the virtual work method. A micro-beam and a comb drive are considered as test cases. The impact of the fringing field effects on the accuracy of electrostatic forces is shown through 2D and 3D parametric studies
{"title":"Finite Element Modeling of Electrostatic MEMS Including the Impact of Fringing Field Effects on Forces","authors":"M. Boutaayamou, K. H. Nair, R. Sabariego, P. Dular","doi":"10.1109/ESIME.2006.1643959","DOIUrl":"https://doi.org/10.1109/ESIME.2006.1643959","url":null,"abstract":"The numerical models describing the behaviour of electrostatically actuated microsystems often disregard fringing fields. However, taking the fringing fields into account is crucial for an accurate computation of the electrostatic forces. In this work, the finite element method is applied for modeling electrostatic actuators. The electrostatic force distribution is obtained by locally applying the virtual work method. A micro-beam and a comb drive are considered as test cases. The impact of the fringing field effects on the accuracy of electrostatic forces is shown through 2D and 3D parametric studies","PeriodicalId":60796,"journal":{"name":"微纳电子与智能制造","volume":"22 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2006-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82508061","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}
Pub Date : 2006-04-24DOI: 10.1109/ESIME.2006.1644034
X. Jordà, M. Vellvehí, F. Madrid, J. Gálvez, P. Godignon, J. Millán
Thermal simulation is nowadays the basic thermal management design tool to predict temperature distributions and power fluxes of complex assemblies. Nevertheless, the simulation results can be inaccurate due to the uncertainty of the values of the parameters involved in the modelisation, as it is the case of the dielectric layer of the IMS substrates. We propose a methodology for the in-situ measurement of the thermal conductivity of this dielectric layer. Two typical power assembly structures based on two types of substrates and a thermal assessment chip, have been simulated and their thermal resistance deduced. The corresponding experimental results have validated the simulations and, consequently, the thermal conductivity extraction method proposed
{"title":"Comparison Between Simulated and Experimental Thermal Resistances of Power Devices Using an Specific Test Chip","authors":"X. Jordà, M. Vellvehí, F. Madrid, J. Gálvez, P. Godignon, J. Millán","doi":"10.1109/ESIME.2006.1644034","DOIUrl":"https://doi.org/10.1109/ESIME.2006.1644034","url":null,"abstract":"Thermal simulation is nowadays the basic thermal management design tool to predict temperature distributions and power fluxes of complex assemblies. Nevertheless, the simulation results can be inaccurate due to the uncertainty of the values of the parameters involved in the modelisation, as it is the case of the dielectric layer of the IMS substrates. We propose a methodology for the in-situ measurement of the thermal conductivity of this dielectric layer. Two typical power assembly structures based on two types of substrates and a thermal assessment chip, have been simulated and their thermal resistance deduced. The corresponding experimental results have validated the simulations and, consequently, the thermal conductivity extraction method proposed","PeriodicalId":60796,"journal":{"name":"微纳电子与智能制造","volume":"12 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2006-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81693914","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}
Pub Date : 2006-04-24DOI: 10.1109/ESIME.2006.1644042
J. Auersperg, R. Dudek, B. Michel
Microelectronic assemblies are basically compounds of several high precision materials with quite different Young's moduli and thermal expansion coefficients (CTE). Additionally, various kinds of inhomogeneity, residual stresses generated by several steps of the manufacturing process and extreme thermal environmental conditions contribute to interface delamination, chip cracking and fatigue of solder interconnects. For that reason, numerical investigations by means of nonlinear FEA together with conventional strength hypotheses are frequently used for design optimizations and sensitivity analyses. So, design studies on the basis of parameterized FE-models and DOE/RSM-approaches help to optimize electronic components at early phases of the product development process. But, this methodology typically bases on classical stress/strain strength evaluations or/and life time estimations of solder interconnects using modified Coffin-Manson approaches, whereas delamination or bulk fracture mechanisms usually remain unconsidered. By means of a representative microelectronics assembly this contribution is going to figure out and discuss ways and challenges of using numerical fatigue evaluation and fracture mechanics approaches in connection with parameterized finite element modeling based DOE/RSM-concepts. That is, the evaluation of mixed mode interface delamination phenomena utilizing the VCCT-methodology, classical strength hypotheses along with fracture mechanics approaches and modified Coffin-Manson thermal fatigue estimation of solder joints will be simultaneously applied within a multi-objective optimization towards a thermo-mechanical reliable design
{"title":"Combined Fracture, Delamination Risk and Fatigue Evaluation of Advanced Microelectronics Applications towards RSM/DOE Concepts","authors":"J. Auersperg, R. Dudek, B. Michel","doi":"10.1109/ESIME.2006.1644042","DOIUrl":"https://doi.org/10.1109/ESIME.2006.1644042","url":null,"abstract":"Microelectronic assemblies are basically compounds of several high precision materials with quite different Young's moduli and thermal expansion coefficients (CTE). Additionally, various kinds of inhomogeneity, residual stresses generated by several steps of the manufacturing process and extreme thermal environmental conditions contribute to interface delamination, chip cracking and fatigue of solder interconnects. For that reason, numerical investigations by means of nonlinear FEA together with conventional strength hypotheses are frequently used for design optimizations and sensitivity analyses. So, design studies on the basis of parameterized FE-models and DOE/RSM-approaches help to optimize electronic components at early phases of the product development process. But, this methodology typically bases on classical stress/strain strength evaluations or/and life time estimations of solder interconnects using modified Coffin-Manson approaches, whereas delamination or bulk fracture mechanisms usually remain unconsidered. By means of a representative microelectronics assembly this contribution is going to figure out and discuss ways and challenges of using numerical fatigue evaluation and fracture mechanics approaches in connection with parameterized finite element modeling based DOE/RSM-concepts. That is, the evaluation of mixed mode interface delamination phenomena utilizing the VCCT-methodology, classical strength hypotheses along with fracture mechanics approaches and modified Coffin-Manson thermal fatigue estimation of solder joints will be simultaneously applied within a multi-objective optimization towards a thermo-mechanical reliable design","PeriodicalId":60796,"journal":{"name":"微纳电子与智能制造","volume":"163 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2006-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83187966","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：