Pub Date : 1996-07-15DOI: 10.1299/JSMEA1993.39.3_297
Masao Tanaka, T. Adachi, Y. Tomita
Mechanical remodeling of bone is a kind of adaptation and is performed to regulate the stress and/or strain in the tissue in response to the changing mechanical environment due to tissue growth and atrophy. We propose a phenomenological model of mechanical remodeling of bone structure considering residual stress. The lattice continuum model is used to represent the bone structure, such as the trabecular structure of cancellous bones. The basic idea in the previous report, which concerns mechanical remodeling that takes into account the residual stress, is extended to the continuum with the internal tissue structure. A remodeling rate equation of the tissue structure is expressed so as to result in an equistress state at the remodeling equilibrium as an optimality of the bone structure in the steady state. A case study of a long bone under bending moment reveals basic features of the proposed model of the stress regulation process. Remodeling simulation for the vertebral body under repetitive bending with compression demonstrates apparent density and residual stress distributions that coincide with the experimental observations.
{"title":"Mechanical Remodeling of Bone Structure Considering Residual Stress","authors":"Masao Tanaka, T. Adachi, Y. Tomita","doi":"10.1299/JSMEA1993.39.3_297","DOIUrl":"https://doi.org/10.1299/JSMEA1993.39.3_297","url":null,"abstract":"Mechanical remodeling of bone is a kind of adaptation and is performed to regulate the stress and/or strain in the tissue in response to the changing mechanical environment due to tissue growth and atrophy. We propose a phenomenological model of mechanical remodeling of bone structure considering residual stress. The lattice continuum model is used to represent the bone structure, such as the trabecular structure of cancellous bones. The basic idea in the previous report, which concerns mechanical remodeling that takes into account the residual stress, is extended to the continuum with the internal tissue structure. A remodeling rate equation of the tissue structure is expressed so as to result in an equistress state at the remodeling equilibrium as an optimality of the bone structure in the steady state. A case study of a long bone under bending moment reveals basic features of the proposed model of the stress regulation process. Remodeling simulation for the vertebral body under repetitive bending with compression demonstrates apparent density and residual stress distributions that coincide with the experimental observations.","PeriodicalId":143127,"journal":{"name":"JSME international journal. Series A, mechanics and material engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127584560","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 : 1996-07-15DOI: 10.1299/JSMEA1993.39.3_422
M. Shimada, T. Yoshii
An ultrasound detection system with optical heterodynes shows nonlinear behavior in the large-amplitude region (>λ/8, λ: wavelength of detecting light), and entails some problems in the measurement of laser ultrasound (ultrasound generated by laser deposition), especially for thin specimens. We studied the mechanism of the nonlinear response and found a method for improving it. Through experiments, we devised an improved demodulation method using signal processing techniques to extract actual ultrasonic waveforms in the large-amplitude region, and confirmed its effectiveness. We also carried out numerical experiments to investigate the characteristics of our improved demodulation method and the standard demodulation method. The results show that compared with the standard demodulation method, our method is more robust against noise of beat signals. and more useful for measuring laser ultrasound even in the small-amplitude region.
{"title":"Improvement of Optical Probe Response to Large-Amplitude Ultrasound","authors":"M. Shimada, T. Yoshii","doi":"10.1299/JSMEA1993.39.3_422","DOIUrl":"https://doi.org/10.1299/JSMEA1993.39.3_422","url":null,"abstract":"An ultrasound detection system with optical heterodynes shows nonlinear behavior in the large-amplitude region (>λ/8, λ: wavelength of detecting light), and entails some problems in the measurement of laser ultrasound (ultrasound generated by laser deposition), especially for thin specimens. We studied the mechanism of the nonlinear response and found a method for improving it. Through experiments, we devised an improved demodulation method using signal processing techniques to extract actual ultrasonic waveforms in the large-amplitude region, and confirmed its effectiveness. We also carried out numerical experiments to investigate the characteristics of our improved demodulation method and the standard demodulation method. The results show that compared with the standard demodulation method, our method is more robust against noise of beat signals. and more useful for measuring laser ultrasound even in the small-amplitude region.","PeriodicalId":143127,"journal":{"name":"JSME international journal. Series A, mechanics and material engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124674820","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 : 1996-07-15DOI: 10.1299/JSMEA1993.39.3_346
T. Iwaki
The stress and strain in a very thin film under uniaxial tension are analyzed based on the motion of particles in the film by means of two-dimensional molecular dynamics (MD) simulation. The Lennard-Jones(L-J) potential is assumed as a two-body potential. The tensile load is applied by elongating the fundamental cell longitudinally. The numerical results show that the stress decreases considerably as the size of the region for defining the stress decreases. It is found that more than 130 particles are necessary in the region for the stress concept to be applicable in continuum mechanics.
{"title":"Molecular Dynamics Study on Stress-Strain in Very Thin Film : Size and Location of Region for Defining Stress and Strain","authors":"T. Iwaki","doi":"10.1299/JSMEA1993.39.3_346","DOIUrl":"https://doi.org/10.1299/JSMEA1993.39.3_346","url":null,"abstract":"The stress and strain in a very thin film under uniaxial tension are analyzed based on the motion of particles in the film by means of two-dimensional molecular dynamics (MD) simulation. The Lennard-Jones(L-J) potential is assumed as a two-body potential. The tensile load is applied by elongating the fundamental cell longitudinally. The numerical results show that the stress decreases considerably as the size of the region for defining the stress decreases. It is found that more than 130 particles are necessary in the region for the stress concept to be applicable in continuum mechanics.","PeriodicalId":143127,"journal":{"name":"JSME international journal. Series A, mechanics and material engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114988864","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 : 1996-07-15DOI: 10.1299/JSMEA1993.39.3_456
N. Nagashima, S. Matsuoka, K. Miyahara
Atomic force microscopes (AFMs) can be used for atomic-scale imaging and nanofabrication. Taking advantage of this we developed a nanoindentation technique. Hardness measurements were carried out on cementite-spheroidized S 25 C carbon steel (Vickers hardness H v ,= 128) and 400°C-tempered SNCM 439 low alloy steel (H v = 414), using a cantilever with a three-sided pyramidal diamond tip. The depth of indentations created was between 14 and 330 nm. The difference in hardness between S 25 C and SNCM 439 steels was detected in the nanoscopic region. From these results, it was concluded that nanoindentation was realized with AFM.
原子力显微镜(AFMs)可用于原子尺度成像和纳米制造。利用这一点，我们开发了一种纳米压痕技术。采用三面锥体金刚石尖悬臂梁对渗碳球化的s25c碳钢(维氏硬度H v = 128)和400℃回火的SNCM 439低合金钢(H v = 414)进行了硬度测量。产生的压痕深度在14到330 nm之间。s25c钢和SNCM 439钢的硬度在纳米尺度上存在差异。结果表明，利用原子力显微镜可以实现纳米压痕。
{"title":"Nanoscopic Hardness Measurement by Atomic Force Microscope","authors":"N. Nagashima, S. Matsuoka, K. Miyahara","doi":"10.1299/JSMEA1993.39.3_456","DOIUrl":"https://doi.org/10.1299/JSMEA1993.39.3_456","url":null,"abstract":"Atomic force microscopes (AFMs) can be used for atomic-scale imaging and nanofabrication. Taking advantage of this we developed a nanoindentation technique. Hardness measurements were carried out on cementite-spheroidized S 25 C carbon steel (Vickers hardness H v ,= 128) and 400°C-tempered SNCM 439 low alloy steel (H v = 414), using a cantilever with a three-sided pyramidal diamond tip. The depth of indentations created was between 14 and 330 nm. The difference in hardness between S 25 C and SNCM 439 steels was detected in the nanoscopic region. From these results, it was concluded that nanoindentation was realized with AFM.","PeriodicalId":143127,"journal":{"name":"JSME international journal. Series A, mechanics and material engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130481188","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 : 1996-07-15DOI: 10.1299/JSMEA1993.39.3_429
Y. Itoh, Y. Ishiwata
The microstructure of newly developed yttrium-oxide-dispersed tungsten alloy was investigated by examining the effect of sintering temperature on the particle size of yttrium oxide and the crystal size of tungsten. Also, it was confirmed that the bending strength of yttrium-oxide-dispersed tungsten alloy was more strongly affected by the sintering temperature in comparison with a sintered tungsten sample. The residual stress, induced by the coefficient of thermal expansion mismatch, is analyzed for the tungsten matrix composite with a particle of yttrium oxide using the finite element method. Because of the high residual stress, particles of yttrium oxide become crack initiation sites under the fabrication process. Finally, it is also shown that the bending strength of yttrium-oxide dispersed tungsten alloy can be estimated simply by the fracture mechanics approach, based on the assumption of a flaw introduction effect by the yttrium oxide dispersion.
{"title":"Strength Properties of Yttrium-Oxide-Dispersed Tungsten Alloy","authors":"Y. Itoh, Y. Ishiwata","doi":"10.1299/JSMEA1993.39.3_429","DOIUrl":"https://doi.org/10.1299/JSMEA1993.39.3_429","url":null,"abstract":"The microstructure of newly developed yttrium-oxide-dispersed tungsten alloy was investigated by examining the effect of sintering temperature on the particle size of yttrium oxide and the crystal size of tungsten. Also, it was confirmed that the bending strength of yttrium-oxide-dispersed tungsten alloy was more strongly affected by the sintering temperature in comparison with a sintered tungsten sample. The residual stress, induced by the coefficient of thermal expansion mismatch, is analyzed for the tungsten matrix composite with a particle of yttrium oxide using the finite element method. Because of the high residual stress, particles of yttrium oxide become crack initiation sites under the fabrication process. Finally, it is also shown that the bending strength of yttrium-oxide dispersed tungsten alloy can be estimated simply by the fracture mechanics approach, based on the assumption of a flaw introduction effect by the yttrium oxide dispersion.","PeriodicalId":143127,"journal":{"name":"JSME international journal. Series A, mechanics and material engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126704630","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 : 1996-07-15DOI: 10.1299/JSMEA1993.39.3_415
Yasuhiko Nakanishi, S. Nakagiri
This paper deals with optimization of truss topology using boundary cycle in algebraic topology. Elimination of unnecessary members from the ground structure, one of the popular means to optimize truss topology, is employed. The elimination has a disadvantage that unstable structures possibly appear in the process of the optimization. Boundary operator, which has the ability to represent equilibrium of internal force in members, is used to generate the boundary cycle from chain. Design variables derived by the boundary cycle can always satisfy this equilibrium and avoid a category of unstable structures without imposing any constraint. An attempt is made through numerical examples to minimize the total weight of a plane truss, which is fixed to a rigid wall and supports a vertical load acting at a point distant from the wall, under the condition that the distribution of strain energy density is uniform and equal to a certain value. The validity of this formulation is verified by the numerical examples concerned with the weight minimization of the truss.
{"title":"Optimization of truss topology using boundary cycle : Derivation of design variables to avoid inexpedient structure","authors":"Yasuhiko Nakanishi, S. Nakagiri","doi":"10.1299/JSMEA1993.39.3_415","DOIUrl":"https://doi.org/10.1299/JSMEA1993.39.3_415","url":null,"abstract":"This paper deals with optimization of truss topology using boundary cycle in algebraic topology. Elimination of unnecessary members from the ground structure, one of the popular means to optimize truss topology, is employed. The elimination has a disadvantage that unstable structures possibly appear in the process of the optimization. Boundary operator, which has the ability to represent equilibrium of internal force in members, is used to generate the boundary cycle from chain. Design variables derived by the boundary cycle can always satisfy this equilibrium and avoid a category of unstable structures without imposing any constraint. An attempt is made through numerical examples to minimize the total weight of a plane truss, which is fixed to a rigid wall and supports a vertical load acting at a point distant from the wall, under the condition that the distribution of strain energy density is uniform and equal to a certain value. The validity of this formulation is verified by the numerical examples concerned with the weight minimization of the truss.","PeriodicalId":143127,"journal":{"name":"JSME international journal. Series A, mechanics and material engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121203156","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 : 1996-07-15DOI: 10.1299/JSMEA1993.39.3_398
K. Mori, H. Isono, T. Sugibayashi
Nonlinear fracture behavior of stepped-lap bonded joints is studied. The joints used have adherends of eight kinds of metals: three of carbon steel, four of aluminum alloy and one of brass. The joints also have various thicknesses, lap lengths and step numbers. The effect of Young's modulus and yield strength of adherend material on the joint strength is calculated by means of elastoplastic finite-element analysis. It is found that the strength of the joint which yields at an adherend corner is nearly equal to the yield strength of the adherend material, because the displacement of the adhesive layer increases abruptly after the adherend yield and exceeds the layer's deformation capacity. The joint strength diagrams obtained by the strength prediction method applying our adhesion criteria show good agreement with the experimental results for all currently available joints having various dimensions and materials.
{"title":"Fracture behavior and strength of stepped-lap bonded joint with adhesive resin under tensile loading","authors":"K. Mori, H. Isono, T. Sugibayashi","doi":"10.1299/JSMEA1993.39.3_398","DOIUrl":"https://doi.org/10.1299/JSMEA1993.39.3_398","url":null,"abstract":"Nonlinear fracture behavior of stepped-lap bonded joints is studied. The joints used have adherends of eight kinds of metals: three of carbon steel, four of aluminum alloy and one of brass. The joints also have various thicknesses, lap lengths and step numbers. The effect of Young's modulus and yield strength of adherend material on the joint strength is calculated by means of elastoplastic finite-element analysis. It is found that the strength of the joint which yields at an adherend corner is nearly equal to the yield strength of the adherend material, because the displacement of the adhesive layer increases abruptly after the adherend yield and exceeds the layer's deformation capacity. The joint strength diagrams obtained by the strength prediction method applying our adhesion criteria show good agreement with the experimental results for all currently available joints having various dimensions and materials.","PeriodicalId":143127,"journal":{"name":"JSME international journal. Series A, mechanics and material engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115978096","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 : 1996-07-15DOI: 10.1299/JSMEA1993.39.3_291
T. Kitamura, R. Ohtani, T. Yamanaka, K. Yashiro
Failure of microelement such as a conductor in an LSI originates mostly from an atomic-scale defect. In this study, the nucleation process of grain boundary groove in an aluminum conductor is analyzed in terms of atomic mechanics. The motion of atoms near an intersection between grain boundary and surface near the melting temperature is simulated by the molecular dynamics. It, however, is impossible to analyze initiation of groove at the intersection in an actual component at its operating temperature by the molecular dynamics because the simulation can only reproduce the behavior of atoms over a very short period (about 10 -9 sec) due to the limitation of computational resources. A Monte Carlo method to simulate the atomic behavior in a longer period is proposed, focusing on the jumps of atoms along the surface. The grooving at a reasonable temperature is successfully simulated by the proposed method.
{"title":"Atomic Mechanics Simulation on Nucleation Process of Grain Boundary Groove in Aluminum Conductor of Microelectronic Packages","authors":"T. Kitamura, R. Ohtani, T. Yamanaka, K. Yashiro","doi":"10.1299/JSMEA1993.39.3_291","DOIUrl":"https://doi.org/10.1299/JSMEA1993.39.3_291","url":null,"abstract":"Failure of microelement such as a conductor in an LSI originates mostly from an atomic-scale defect. In this study, the nucleation process of grain boundary groove in an aluminum conductor is analyzed in terms of atomic mechanics. The motion of atoms near an intersection between grain boundary and surface near the melting temperature is simulated by the molecular dynamics. It, however, is impossible to analyze initiation of groove at the intersection in an actual component at its operating temperature by the molecular dynamics because the simulation can only reproduce the behavior of atoms over a very short period (about 10 -9 sec) due to the limitation of computational resources. A Monte Carlo method to simulate the atomic behavior in a longer period is proposed, focusing on the jumps of atoms along the surface. The grooving at a reasonable temperature is successfully simulated by the proposed method.","PeriodicalId":143127,"journal":{"name":"JSME international journal. Series A, mechanics and material engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123688195","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 : 1996-04-15DOI: 10.1299/JSMEA1993.39.2_252
K. Seo, M. Kusaka, F. Nogata, Yoshiki Urakami
In this study, a new method for evaluating the adhesive strength of the interface between resin liner film and cement mortar has been developed. The peel test for vinyl ester resin liner films on cement mortar surfaces was carried out. The critical energy release rate (G c value) was obtained from the peel load and crack length measured during the peel test. G c values were not affected by the crack length or the thickness of resin liner film. Therefore it was established that G c values could be used to evaluate the adhesive strength of resin liner film. Furthermore, the effect of primer coats on the adhesive strength of resin liner film was revealed by obtaining the G c values.
{"title":"Evaluation of Adhesive Strength of Resin Liner Film","authors":"K. Seo, M. Kusaka, F. Nogata, Yoshiki Urakami","doi":"10.1299/JSMEA1993.39.2_252","DOIUrl":"https://doi.org/10.1299/JSMEA1993.39.2_252","url":null,"abstract":"In this study, a new method for evaluating the adhesive strength of the interface between resin liner film and cement mortar has been developed. The peel test for vinyl ester resin liner films on cement mortar surfaces was carried out. The critical energy release rate (G c value) was obtained from the peel load and crack length measured during the peel test. G c values were not affected by the crack length or the thickness of resin liner film. Therefore it was established that G c values could be used to evaluate the adhesive strength of resin liner film. Furthermore, the effect of primer coats on the adhesive strength of resin liner film was revealed by obtaining the G c values.","PeriodicalId":143127,"journal":{"name":"JSME international journal. Series A, mechanics and material engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131669633","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 : 1996-04-15DOI: 10.1299/JSMEA1993.39.2_197
S. Ioka, S. Kubo, K. Ohji, J. Kishimoto
Thermal residual stress distributions on the interface and in the vicinity of the intersections of the interface and the free surfaces of bonded dissimilar materials are calculated using the boundary element method. Thermoelastic constant stress terms are calculated using Airy's stress function. The thermal residual stresses, when the thermoelastic constant stress terms are subtracted, show free-edge stress singularity. The values of the order of thermal residual stress singularity and stress distribution functions agree well with the theoretical ones calculated based on Airy's stress function. It is shown that the thermal stress singularity disappears for certain ranges of wedge angles of a pair of materials, as predicted.
{"title":"Thermal Residual Stresses in Bonded Dissimilar Materials and Their Singularities","authors":"S. Ioka, S. Kubo, K. Ohji, J. Kishimoto","doi":"10.1299/JSMEA1993.39.2_197","DOIUrl":"https://doi.org/10.1299/JSMEA1993.39.2_197","url":null,"abstract":"Thermal residual stress distributions on the interface and in the vicinity of the intersections of the interface and the free surfaces of bonded dissimilar materials are calculated using the boundary element method. Thermoelastic constant stress terms are calculated using Airy's stress function. The thermal residual stresses, when the thermoelastic constant stress terms are subtracted, show free-edge stress singularity. The values of the order of thermal residual stress singularity and stress distribution functions agree well with the theoretical ones calculated based on Airy's stress function. It is shown that the thermal stress singularity disappears for certain ranges of wedge angles of a pair of materials, as predicted.","PeriodicalId":143127,"journal":{"name":"JSME international journal. Series A, mechanics and material engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129696164","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}
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