The microstructural characteristic of 1070AI matrix composites reinforced by 0.15 祄 AI2O3 particles whose volume fraction was 40% was investigated by TEM and HREM. The results showed that the interface between the ma...The microstructural characteristic of 1070AI matrix composites reinforced by 0.15 祄 AI2O3 particles whose volume fraction was 40% was investigated by TEM and HREM. The results showed that the interface between the matrix and reinforcements was clean and bonded well, without any interfacial reaction products. There were some preferential crystallographic orientation relationships between Al matrix and AI2O3 particle because of the lattice imperfection on the surface of Al2O3 particles.展开更多
The ceramic coating was formed by using microarc oxidation (MAO) in the electrolytic solution of β-Glycerophosphate sodium salt pentahydrate (β-GP) and calcium acetate (CA). The microstructure, phase structure and p...The ceramic coating was formed by using microarc oxidation (MAO) in the electrolytic solution of β-Glycerophosphate sodium salt pentahydrate (β-GP) and calcium acetate (CA). The microstructure, phase structure and phase composition were investigated with scanning electron microscopy (SEM), atomic force microscope (AFM), energy dispersive X-ray microanalyser (EDX), X-ray photoelectron spectroscopy (XPS), electron probe micro analyzer (EPMA) and X-ray diffraction (XRD). Investigation of the chemical composition of the coating with EDX revealed that Ca and P of high concentration existed in oxide films. XRD patterns indicated that the oxide film was composed of only anatase at low voltage discharge, and that rutile peaks appear in addition to anatase peak with increasing MAO voltage. Despite the existence of Ca and P, compounds concerning Ca and P were not detected in the oxide film.展开更多
High-spin states in ^179Au have been studied experimentally by using the ^149Sm(^35C1, 5n) reaction at beam energies of 164,~180 MeV. The ^35C1 beam was provided by the tandem accelerator at the Japan Atomic En-ergy R...High-spin states in ^179Au have been studied experimentally by using the ^149Sm(^35C1, 5n) reaction at beam energies of 164,~180 MeV. The ^35C1 beam was provided by the tandem accelerator at the Japan Atomic En-ergy Research Institute (JAERI). The target is an isotopically enriched ^149Sm metallic foil of 1.5 mg/cm^2 thickness with a 5.0 mg/cm^2 Pb backing. Measurements of γ-ray excitation functions, X-γ coincidences and γ-γ-t coincidences were performed with 13 HPGe's with BGO anti-Compton shields and three LOAX detectors.展开更多
Study of in-beam γ-ray spectroscopy of ^145Tb has been carried out by using ^118Sn (32 S, 1p4n) ^145Tb reaction. Excitation functions, X-γ-t and γ-γ-t coincidences and γ-ray anisotropies were measured. Here, t re...Study of in-beam γ-ray spectroscopy of ^145Tb has been carried out by using ^118Sn (32 S, 1p4n) ^145Tb reaction. Excitation functions, X-γ-t and γ-γ-t coincidences and γ-ray anisotropies were measured. Here, t refers to the relative time difference between any two coincident γ-rays detected within ±200 ns. A level scheme of ^14tTb, including 81 γ-transitions as shown in Fig.l, has been established up to 7.4 MeV in excitation energy and spinparity assignments for most of the observed levels have been done. The level structure shows characteristics of spherical nucleus. The observed states with excitation energies less than 2 MeV are interpreted by coupling an h11/2 proton to the 2^+, 4^+ and 3^- core excitations in ^144Gd. The excitation energies of these states fit wellin to the systematics of the neighboring odd-A N=80 isotones, and are well reproduced by the quasiparticle-cluster interaction calculations[1]. Semi-empirical shell model calculations[2] have been done for the higher-lying levels. The results clearly reveal the characteristic features of multiparticle configurations in a spherical nucleus. Specific configurations are proposed for the yrast and some non-yrast levels.展开更多
This paper presents a formal approach to design of a solver of an intelligent management information system and its implementation. The approach implies set theoretic modeling based on the general systems concepts and...This paper presents a formal approach to design of a solver of an intelligent management information system and its implementation. The approach implies set theoretic modeling based on the general systems concepts and implementation in the extProlog.There are research efforts which attack (optimization) problems using the set theory and logics. Furthermore, they use logic programming languages for their implementation. Although their methods look quite similar to the approach of this paper, there are clear differences between them. This paper is interested in exploration of the solving system rather than algorithms.The paper first presents a design and implementation procedure of a solver. Then, classification of problems is discussed. The least structured class of the classification is the target of this paper. A data mining system is an example of the class.Formal theories are derived for the design procedure assuming the least structured case. A solving strategy, which is called a hill climbing method with a push down stack, is proposed on the theories.A data mining system is used as an example to illustrate the results.Finally, a full implementation in extProlog is presented for the data mining system.展开更多
基金This research is supported by the National Natural Science Foundation of China (under Grant No.59771014 and No.50071019). The help of the National Advanced Material Open Research Lab of Tsinghua University is gratefully acknowledged.
文摘The microstructural characteristic of 1070AI matrix composites reinforced by 0.15 祄 AI2O3 particles whose volume fraction was 40% was investigated by TEM and HREM. The results showed that the interface between the matrix and reinforcements was clean and bonded well, without any interfacial reaction products. There were some preferential crystallographic orientation relationships between Al matrix and AI2O3 particle because of the lattice imperfection on the surface of Al2O3 particles.
文摘The ceramic coating was formed by using microarc oxidation (MAO) in the electrolytic solution of β-Glycerophosphate sodium salt pentahydrate (β-GP) and calcium acetate (CA). The microstructure, phase structure and phase composition were investigated with scanning electron microscopy (SEM), atomic force microscope (AFM), energy dispersive X-ray microanalyser (EDX), X-ray photoelectron spectroscopy (XPS), electron probe micro analyzer (EPMA) and X-ray diffraction (XRD). Investigation of the chemical composition of the coating with EDX revealed that Ca and P of high concentration existed in oxide films. XRD patterns indicated that the oxide film was composed of only anatase at low voltage discharge, and that rutile peaks appear in addition to anatase peak with increasing MAO voltage. Despite the existence of Ca and P, compounds concerning Ca and P were not detected in the oxide film.
文摘High-spin states in ^179Au have been studied experimentally by using the ^149Sm(^35C1, 5n) reaction at beam energies of 164,~180 MeV. The ^35C1 beam was provided by the tandem accelerator at the Japan Atomic En-ergy Research Institute (JAERI). The target is an isotopically enriched ^149Sm metallic foil of 1.5 mg/cm^2 thickness with a 5.0 mg/cm^2 Pb backing. Measurements of γ-ray excitation functions, X-γ coincidences and γ-γ-t coincidences were performed with 13 HPGe's with BGO anti-Compton shields and three LOAX detectors.
文摘Study of in-beam γ-ray spectroscopy of ^145Tb has been carried out by using ^118Sn (32 S, 1p4n) ^145Tb reaction. Excitation functions, X-γ-t and γ-γ-t coincidences and γ-ray anisotropies were measured. Here, t refers to the relative time difference between any two coincident γ-rays detected within ±200 ns. A level scheme of ^14tTb, including 81 γ-transitions as shown in Fig.l, has been established up to 7.4 MeV in excitation energy and spinparity assignments for most of the observed levels have been done. The level structure shows characteristics of spherical nucleus. The observed states with excitation energies less than 2 MeV are interpreted by coupling an h11/2 proton to the 2^+, 4^+ and 3^- core excitations in ^144Gd. The excitation energies of these states fit wellin to the systematics of the neighboring odd-A N=80 isotones, and are well reproduced by the quasiparticle-cluster interaction calculations[1]. Semi-empirical shell model calculations[2] have been done for the higher-lying levels. The results clearly reveal the characteristic features of multiparticle configurations in a spherical nucleus. Specific configurations are proposed for the yrast and some non-yrast levels.
文摘This paper presents a formal approach to design of a solver of an intelligent management information system and its implementation. The approach implies set theoretic modeling based on the general systems concepts and implementation in the extProlog.There are research efforts which attack (optimization) problems using the set theory and logics. Furthermore, they use logic programming languages for their implementation. Although their methods look quite similar to the approach of this paper, there are clear differences between them. This paper is interested in exploration of the solving system rather than algorithms.The paper first presents a design and implementation procedure of a solver. Then, classification of problems is discussed. The least structured class of the classification is the target of this paper. A data mining system is an example of the class.Formal theories are derived for the design procedure assuming the least structured case. A solving strategy, which is called a hill climbing method with a push down stack, is proposed on the theories.A data mining system is used as an example to illustrate the results.Finally, a full implementation in extProlog is presented for the data mining system.
