The potential of the semiconducting compound /spl beta/-Zn/sub 4/Sb/sub 3/ for thermoelectric energy conversion was investigated. The thermoelectric properties were measured on hot-pressed samples characterized by X-ray and microprobe analysis. All samples had p-type conductivity and the thermoelectric properties of the samples were measured between room temperature and 400/spl deg/C. Exceptionally low thermal conductivity values were measured and the room temperature lattice thermal conductivity was estimated at 7 mW cm/sup -1/ K/sup -1/. High figures of merit were obtained between 200 and 400/spl deg/C and a maximum dimensionless thermoelectric figure of merit ZT of about 1.3 was obtained at a temperature of 400/spl deg/C. The stability of the compound was investigated by thermogravimetric studies and showed that the samples were stable under Ar atmosphere up to about 400/spl deg/C and up to 250/spl deg/C in dynamic vacuum. The high thermoelectric performance of /spl beta/-Zn/sub 4/Sb/sub 3/ in the 200 to 400/spl deg/C temperature range fills the gap established in the ZT spectrum of p-type state-of-the-art thermoelectric materials between Bi/sub 2/Te/sub 3/-based alloys and PbTe-based alloys. This material, relatively inexpensive, could be used in more efficient thermoelectric generators for waste heat recovery and automobile industry applications, for example.
{"title":"A low thermal conductivity compound for thermoelectric applications: /spl beta/-Zn4Sb3","authors":"T. Caillat, J. Fleurial, A. Borshchevsky","doi":"10.1109/ICT.1996.553280","DOIUrl":"https://doi.org/10.1109/ICT.1996.553280","url":null,"abstract":"The potential of the semiconducting compound /spl beta/-Zn/sub 4/Sb/sub 3/ for thermoelectric energy conversion was investigated. The thermoelectric properties were measured on hot-pressed samples characterized by X-ray and microprobe analysis. All samples had p-type conductivity and the thermoelectric properties of the samples were measured between room temperature and 400/spl deg/C. Exceptionally low thermal conductivity values were measured and the room temperature lattice thermal conductivity was estimated at 7 mW cm/sup -1/ K/sup -1/. High figures of merit were obtained between 200 and 400/spl deg/C and a maximum dimensionless thermoelectric figure of merit ZT of about 1.3 was obtained at a temperature of 400/spl deg/C. The stability of the compound was investigated by thermogravimetric studies and showed that the samples were stable under Ar atmosphere up to about 400/spl deg/C and up to 250/spl deg/C in dynamic vacuum. The high thermoelectric performance of /spl beta/-Zn/sub 4/Sb/sub 3/ in the 200 to 400/spl deg/C temperature range fills the gap established in the ZT spectrum of p-type state-of-the-art thermoelectric materials between Bi/sub 2/Te/sub 3/-based alloys and PbTe-based alloys. This material, relatively inexpensive, could be used in more efficient thermoelectric generators for waste heat recovery and automobile industry applications, for example.","PeriodicalId":447328,"journal":{"name":"Fifteenth International Conference on Thermoelectrics. Proceedings ICT '96","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130948604","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 thermoelectric figure of merit z is computed for bipolar semiconducting materials with a degenerate gas of current carriers and a nonparabolic band structure. The factors that affect the value of z are analyzed. It is established that the figure of merit of such materials increases monotonically with increasing band gap, in contrast with semiconductors with a parabolic band. It is shown that zT<3 is always true in crystalline thermoelectric materials.
{"title":"The theoretical analysis of the thermoelectric semiconducting crystalline materials figure of merit","authors":"L. Bulat, V. Zakordonets","doi":"10.1109/ICT.1996.553294","DOIUrl":"https://doi.org/10.1109/ICT.1996.553294","url":null,"abstract":"The thermoelectric figure of merit z is computed for bipolar semiconducting materials with a degenerate gas of current carriers and a nonparabolic band structure. The factors that affect the value of z are analyzed. It is established that the figure of merit of such materials increases monotonically with increasing band gap, in contrast with semiconductors with a parabolic band. It is shown that zT<3 is always true in crystalline thermoelectric materials.","PeriodicalId":447328,"journal":{"name":"Fifteenth International Conference on Thermoelectrics. Proceedings ICT '96","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114038243","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 HZ-14 is a thermoelectric module that converts low grade, waste heat into electricity. To obtain optimum performance from the HZ-14, it is important to address several key points when using the module in an application. These key points in the use of the module are discussed and methods of identifying the causes of inferior performance are addressed. The performance characteristics of the module are also described.
{"title":"Use, application and testing of the HZ-14 thermoelectric module","authors":"F.A. Leavitt, N. Elsner, J. Bass","doi":"10.1109/ICT.1996.553508","DOIUrl":"https://doi.org/10.1109/ICT.1996.553508","url":null,"abstract":"The HZ-14 is a thermoelectric module that converts low grade, waste heat into electricity. To obtain optimum performance from the HZ-14, it is important to address several key points when using the module in an application. These key points in the use of the module are discussed and methods of identifying the causes of inferior performance are addressed. The performance characteristics of the module are also described.","PeriodicalId":447328,"journal":{"name":"Fifteenth International Conference on Thermoelectrics. Proceedings ICT '96","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124742056","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}
V. Kutasov, L. N. Luk'yanova, P. Konstantinov, G. T. Alekseeva
Thermoelectric and galvanomagnetic properties of n-Bi/sub 2/Te/sub 3-x/Se/sub x/ (x<0.4) solid solutions with the carrier density /spl les/1.10/sup 18/ cm/sup -3/ are studied. Some peculiarities of the mobility temperature dependence with account of the effective scattering parameter r/sub ef/ are discussed.
{"title":"Charge carrier mobility in Bi2Te/sub 3-x/Sex(x<0.4) solid solution with excess of Te","authors":"V. Kutasov, L. N. Luk'yanova, P. Konstantinov, G. T. Alekseeva","doi":"10.1109/ICT.1996.553253","DOIUrl":"https://doi.org/10.1109/ICT.1996.553253","url":null,"abstract":"Thermoelectric and galvanomagnetic properties of n-Bi/sub 2/Te/sub 3-x/Se/sub x/ (x<0.4) solid solutions with the carrier density /spl les/1.10/sup 18/ cm/sup -3/ are studied. Some peculiarities of the mobility temperature dependence with account of the effective scattering parameter r/sub ef/ are discussed.","PeriodicalId":447328,"journal":{"name":"Fifteenth International Conference on Thermoelectrics. Proceedings ICT '96","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124752911","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}
Y. Gurevich, G. Logvinov, O. I. Lyubimov, O. Titov
The physical transparency of thermopower phenomenon in unipolar case and the clearness of calculation lead to the following paradoxical results: in the case of a bipolar medium the situation seems to be equally obvious, and so the same calculation scheme is used. The aim of this paper is to show that situation changes in bipolar media in principle. If a semiconductor specimen contacts with a heater with temperature T/sub 1/ on the surface x=-a and with a cooler with temperature T/sub 2/ on the surface x=+a, the chemical potential of the electrons and holes are heterogeneous in space and different in all points of the specimen. Thus there are two Fermi quasilevels even in the quasineutrality approximation, and single common "gradient of electrochemical potential" of electrons and holes is absent. One more problem arises when bulk and surface recombinations take place: the correct determination of electron and hole equilibrium concentrations and boundary conditions when thermoelectric current flows in a closed circuit. The aims of this paper are to show the methods of thermopower calculations in case mentioned above and which physical phenomena determine its value.
{"title":"On the role of the bulk and surface recombination in the thermopower in bipolar semiconductors","authors":"Y. Gurevich, G. Logvinov, O. I. Lyubimov, O. Titov","doi":"10.1109/ICT.1996.553300","DOIUrl":"https://doi.org/10.1109/ICT.1996.553300","url":null,"abstract":"The physical transparency of thermopower phenomenon in unipolar case and the clearness of calculation lead to the following paradoxical results: in the case of a bipolar medium the situation seems to be equally obvious, and so the same calculation scheme is used. The aim of this paper is to show that situation changes in bipolar media in principle. If a semiconductor specimen contacts with a heater with temperature T/sub 1/ on the surface x=-a and with a cooler with temperature T/sub 2/ on the surface x=+a, the chemical potential of the electrons and holes are heterogeneous in space and different in all points of the specimen. Thus there are two Fermi quasilevels even in the quasineutrality approximation, and single common \"gradient of electrochemical potential\" of electrons and holes is absent. One more problem arises when bulk and surface recombinations take place: the correct determination of electron and hole equilibrium concentrations and boundary conditions when thermoelectric current flows in a closed circuit. The aims of this paper are to show the methods of thermopower calculations in case mentioned above and which physical phenomena determine its value.","PeriodicalId":447328,"journal":{"name":"Fifteenth International Conference on Thermoelectrics. Proceedings ICT '96","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124869792","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 performance of a thermoelectric (TE) heat exchanger assembly is greatly affected by the quality of the thermal junctions connecting the modules and the mounting surfaces of the heat/cold sinks. The quality of this junction, in turn is affected by many different variables. These include heat sink surface quality, quantity of thermal grease, contaminates in the thermal grease, assembly screw torque, tapped hole quality, surface finish of the modules and the variance in module heights. Until now, junction quality could only be verified by disassembly of the heat exchanger or inferred from a full cooling performance test of the assembly. This paper details a new, transient test method which accurately and dependably characterizes the module-to-heat-sink thermal junctions. A small current is applied to the TE modules in a thermoelectric assembly. This induces a small temperature difference across the module and between the ceramics of the module and its neighboring heat/cold sink. Power is then removed and the module's ceramics return to the temperature of its neighboring heat sink. The rate of temperature decay is directly proportional to the junction quality. Thus, the residual Seebeck decay waveform directly correlates to thermal junction quality, providing the means for rapidly and accurately characterizing assembly quality.
{"title":"Transient analysis of thermal junctions within a thermoelectric cooling assembly","authors":"M.J. Nagy, R. Buist","doi":"10.1109/ICT.1996.553319","DOIUrl":"https://doi.org/10.1109/ICT.1996.553319","url":null,"abstract":"The performance of a thermoelectric (TE) heat exchanger assembly is greatly affected by the quality of the thermal junctions connecting the modules and the mounting surfaces of the heat/cold sinks. The quality of this junction, in turn is affected by many different variables. These include heat sink surface quality, quantity of thermal grease, contaminates in the thermal grease, assembly screw torque, tapped hole quality, surface finish of the modules and the variance in module heights. Until now, junction quality could only be verified by disassembly of the heat exchanger or inferred from a full cooling performance test of the assembly. This paper details a new, transient test method which accurately and dependably characterizes the module-to-heat-sink thermal junctions. A small current is applied to the TE modules in a thermoelectric assembly. This induces a small temperature difference across the module and between the ceramics of the module and its neighboring heat/cold sink. Power is then removed and the module's ceramics return to the temperature of its neighboring heat sink. The rate of temperature decay is directly proportional to the junction quality. Thus, the residual Seebeck decay waveform directly correlates to thermal junction quality, providing the means for rapidly and accurately characterizing assembly quality.","PeriodicalId":447328,"journal":{"name":"Fifteenth International Conference on Thermoelectrics. Proceedings ICT '96","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128678706","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}
H. Nakagawa, H. Tanaka, A. Kasama, K. Miyamura, H. Masumoto, K. Matsubara
A novel technique to prepare CoSb/sub 3/ materials on a mass production level was studied. Co and Sb were melted together in an alumina crucible at 1373 K, and cast in a copper mold to solidify the melts. The obtained alloyed ingots consist of mainly three phases of CoSb/sub 3/, CoSb/sub 2/ and Sb. To react Sb with CoSb/sub 2/ and get a CoSb/sub 3/ single phase, the ingots were annealed at 823-1073 K. During the heat treatment, Sb and CoSb/sub 2/ phases changed to CoSb/sub 3/ phases and voids. The obtained CoSb/sub 3/ samples show n-type thermoelectric properties. Some factors affecting the properties, for example, Sb/Co atomic ratio, impurity content and density are discussed, based on the experimental data by X-ray diffractometry, optical microscopy, EPMA, chemical analysis and so on. On the other hand, an ingot was ground, mechanically alloyed and hot-pressed. The hot-pressed samples show p-type thermoelectric properties. Moreover, mechanical alloying is effective to reduce the thermal conductivity by refining the crystal grain size of CoSb/sub 3/. As a result, ZT value, 0.10 was obtained at a temperature of 669 K.
{"title":"Thermoelectric properties of CoSb3 prepared by copper mold quenching technique","authors":"H. Nakagawa, H. Tanaka, A. Kasama, K. Miyamura, H. Masumoto, K. Matsubara","doi":"10.1109/ICT.1996.553269","DOIUrl":"https://doi.org/10.1109/ICT.1996.553269","url":null,"abstract":"A novel technique to prepare CoSb/sub 3/ materials on a mass production level was studied. Co and Sb were melted together in an alumina crucible at 1373 K, and cast in a copper mold to solidify the melts. The obtained alloyed ingots consist of mainly three phases of CoSb/sub 3/, CoSb/sub 2/ and Sb. To react Sb with CoSb/sub 2/ and get a CoSb/sub 3/ single phase, the ingots were annealed at 823-1073 K. During the heat treatment, Sb and CoSb/sub 2/ phases changed to CoSb/sub 3/ phases and voids. The obtained CoSb/sub 3/ samples show n-type thermoelectric properties. Some factors affecting the properties, for example, Sb/Co atomic ratio, impurity content and density are discussed, based on the experimental data by X-ray diffractometry, optical microscopy, EPMA, chemical analysis and so on. On the other hand, an ingot was ground, mechanically alloyed and hot-pressed. The hot-pressed samples show p-type thermoelectric properties. Moreover, mechanical alloying is effective to reduce the thermal conductivity by refining the crystal grain size of CoSb/sub 3/. As a result, ZT value, 0.10 was obtained at a temperature of 669 K.","PeriodicalId":447328,"journal":{"name":"Fifteenth International Conference on Thermoelectrics. Proceedings ICT '96","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125307048","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}
W. Pitschke, R. Kurt, A. Heinrich, J. Schumann, J. Thomas, M. Mader
Experimental data on the phase formation process of amorphous Ir/sub x/Si/sub 1-x/ thin films for thermoelectric applications are presented. The composition x varies between 0.30 and 0.40. The phase formation process at temperatures from 300 K up to 1223 K was investigated by means of X-ray diffraction. Distinct phases were observed at the final stage in dependence on the initial composition: Ir/sub 3/Si/sub 4/, Ir/sub 3/Si/sub 5/, and IrSi/sub 3/. The structure of the Ir/sub 3/Si/sub 5/ phase varies in dependence on the chemical composition of the layer. The electrical resistivity of the as-deposited and of annealed at T=973 K and T=1073 K layers was measured at room temperature and in low temperature range.
{"title":"Structure and phase formation in amorphous IrxSi/sub 1-x/ thin films at high temperatures","authors":"W. Pitschke, R. Kurt, A. Heinrich, J. Schumann, J. Thomas, M. Mader","doi":"10.1109/ICT.1996.553535","DOIUrl":"https://doi.org/10.1109/ICT.1996.553535","url":null,"abstract":"Experimental data on the phase formation process of amorphous Ir/sub x/Si/sub 1-x/ thin films for thermoelectric applications are presented. The composition x varies between 0.30 and 0.40. The phase formation process at temperatures from 300 K up to 1223 K was investigated by means of X-ray diffraction. Distinct phases were observed at the final stage in dependence on the initial composition: Ir/sub 3/Si/sub 4/, Ir/sub 3/Si/sub 5/, and IrSi/sub 3/. The structure of the Ir/sub 3/Si/sub 5/ phase varies in dependence on the chemical composition of the layer. The electrical resistivity of the as-deposited and of annealed at T=973 K and T=1073 K layers was measured at room temperature and in low temperature range.","PeriodicalId":447328,"journal":{"name":"Fifteenth International Conference on Thermoelectrics. Proceedings ICT '96","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127750667","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 1961, Cosgrove, McHugh and Tiller reported the effect of micro-segregation in fast-grown bismuth telluride on the thermal conductivity. They attributed a significant increase in this property to the presence of circulating electric currents associated with the non-uniform Seebeck coefficient in the inhomogeneous material. If this effect is an important one, then it could seriously impair the performance of thermoelements made from polycrystalline BiSb alloys since, even if such materials are chemically homogeneous, they will have local variations of the Seebeck coefficient associated with the anisotropy of this parameter in single crystals. We now think that circulating thermoelectric currents are not the main reason for the increase of thermal conductivity in inhomogeneous bismuth telluride. Such currents should have an even smaller effect in BiSb alloys and should not cause any substantial decrease in the figure of merit. This is borne out by measurements on the thermal conductivity of large-grained polycrystalline BiSb alloys. Using a technique for the determination of the electronic component that is described elsewhere, it has been found that the residual thermal conductivity is very close to the lattice component that is predicted form observations on single crystals. This would not be so if there were any significant heat transfer by internal circulating currents.
{"title":"Effect of anisotropy of the Seebeck coefficient on the thermal conductivity of polycrystalline BiSb alloys","authors":"H. Goldsmid, J. Sharp","doi":"10.1109/ICT.1996.553247","DOIUrl":"https://doi.org/10.1109/ICT.1996.553247","url":null,"abstract":"In 1961, Cosgrove, McHugh and Tiller reported the effect of micro-segregation in fast-grown bismuth telluride on the thermal conductivity. They attributed a significant increase in this property to the presence of circulating electric currents associated with the non-uniform Seebeck coefficient in the inhomogeneous material. If this effect is an important one, then it could seriously impair the performance of thermoelements made from polycrystalline BiSb alloys since, even if such materials are chemically homogeneous, they will have local variations of the Seebeck coefficient associated with the anisotropy of this parameter in single crystals. We now think that circulating thermoelectric currents are not the main reason for the increase of thermal conductivity in inhomogeneous bismuth telluride. Such currents should have an even smaller effect in BiSb alloys and should not cause any substantial decrease in the figure of merit. This is borne out by measurements on the thermal conductivity of large-grained polycrystalline BiSb alloys. Using a technique for the determination of the electronic component that is described elsewhere, it has been found that the residual thermal conductivity is very close to the lattice component that is predicted form observations on single crystals. This would not be so if there were any significant heat transfer by internal circulating currents.","PeriodicalId":447328,"journal":{"name":"Fifteenth International Conference on Thermoelectrics. Proceedings ICT '96","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127984596","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 the process of designing multistage thermoelectric cooling systems, accuracy of computations is very important. For this purpose, a useful optimization algorithm was elaborated where the thermoelectric parameters of semiconductors are considered as temperature dependent. The presented method allows an optimal solution for systems, thus achieving maximum COP.
{"title":"Optimization of a multistage thermoelectric cooling system concerning maximum COP","authors":"T. Wartanowicz, A. Czarnecki","doi":"10.1109/ICT.1996.553497","DOIUrl":"https://doi.org/10.1109/ICT.1996.553497","url":null,"abstract":"In the process of designing multistage thermoelectric cooling systems, accuracy of computations is very important. For this purpose, a useful optimization algorithm was elaborated where the thermoelectric parameters of semiconductors are considered as temperature dependent. The presented method allows an optimal solution for systems, thus achieving maximum COP.","PeriodicalId":447328,"journal":{"name":"Fifteenth International Conference on Thermoelectrics. Proceedings ICT '96","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133847708","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}