Abstract: An EC terminal 20 comprises personal information storing means 22 for storing personal information containing user's shopping history, personal information disclosing means 21 for disclosing personal information based on a request from a server 10, and terminal ID disclosing means 23 for disclosing a terminal ID to the server. The server comprises a personal information database 14 for managing personal information of a user, to whom EC services have been provided in the past, personal information requesting means 11 for requesting an EC terminal to disclose user's personal information, and response content deciding means 13 for deciding a response content based on the disclosed personal information and the content of the personal information database. The user stores personal information in the EC terminal, and supplies personal information in all EC services to receive satisfactory services even at a store which he visits for the first time.

Abstract: Disclosed herewith is an attribute information utilization system for enabling network services in various forms. To achieve the above object, the attribute information utilization system of the present invention includes a center device and a terminal. The center device includes a communication block and a server that receives user attribute information and supplies services in accordance with the attribute information. The terminal includes a communication block, a personal attribute information generation/management block that generates/manages user attribute information, an external device interface block connected to a portable storage device and used to exchange attribute information with the memory device. The terminal sends attribute information managed by the personal attribute information generation/management block or inputted from the portable storage device to the center device to receive services from a server.

Abstract: The present invention provides an expiration date monitoring system capable of monitoring an expiration date of a terminal by an effective method. According to an expiration date monitoring system comprising a terminal and a server for monitoring an expiration date of this terminal, the server monitors the expiration date for each terminal, for each function of the terminal and for each content. The terminal receives a renewal command of the expiration date from the server and stores the renewed expiration date of each function. Then, the terminal can activate the terminal itself, each function of the terminal and the access to the content when the current date (current time) is within the expiration date thereof.

Abstract: If the distribution coefficient of an impurity in a compound melt is less than 1, the impurity concentration in the compound melt doped with the impurity increased during a crystal growth in an LEC method. A supplying device replenishes an undoped crystal into the melt in order to keep the impurity concentration constant. The undoped crystal is covered with a liquid encapsulant which is contained in an encapsulant-supporting-cylinder or double-cylinder. Replenishing rate (dQ/dt) of the undoped crystal and the growing rate (dS/dt) should satisfy the equation ##EQU1## The impurity concentration of a grown single crystal is uniform. Whole of the crystal is a single crystal. Electronic properties of the single crystal is uniform from seed end to tail end.

Abstract: If the distribution coefficient of an impurity in a compound melt is less than 1, the impurity concentration in the compound melt doped with the impurity increased during a crystal growth in an LEC method. A supplying device replenishes an undoped crystal into the melt in order to keep the impurity concentration constant. The undoped crystal is covered with a liquid encapsulant which is contained in an encapsulant-supporting-cylinder or double-cylinder. Replenishing rate (dQ/dt) of the undoped crystal and the growing rate (dS/dt) should satisfy the equationdQ/dt=(1-k)dS/dtThe impurity concentration of a grown single crystal is uniform. Whole of the crystal is a single crystal. Electronic properties of the single crystal is uniform from seed end to tail end.

Abstract: An improvement of LEC methods. Highly impurity doped single crystal often suffers from impurity precipitation. The cause of the occurrence of impurity precipitation is supposed to be the supercooling. To avoid the occurrence of supercooling the pulling speed is slowly lowered during the crystal growth in the LEC methods. The beginning of the occurrence of impurity precipitation is delayed by lowering the pulling speed. Additional application of magnetic field is more effective.

Abstract: More than two impurities are doped in a host crystal of compound semiconductors. One of the impurities is an anisoelectronic impurity. One or more than one impurities are isoelectronic impurities. The anisoelectronic impurity determines the electronic property and the carrier density of the semiconductor. Isoelectronic impurity does not change the electronic property. But isoelectronic impurity has an effect of impurity hardening.The impurity atom forms a covalent bond with a host atom. The bond length between an impurity and a host atom differs from the standard bond between host atoms. Although the real bond lengths between an impurity atom and a host atom cannot be measured, the Inventors think the difference of bond lengths generate dislocation or other lattice defects of crystal.

Abstract: A GaAs single crystal containing at least one impurity selected from the group consisting of B, Si, S, Te and In in a concentration of at least 10.sup.15 /cm.sup.3, fluctuation of which is not larger than 20% in a plane perpendicular to a growth direction of the single crystal, which is prepared by pulling up the GaAs single crystal from a GaAs raw material melt contained in a crucible which is encapsulated with a liquid encapsulating layer in an inactive gas atmosphere at a high pressure with applying a magnetic field to the raw material melt.

Abstract: More than two isoelectronic impurities are doped in a host crystal of compound semiconductors of groups III-V.An impurity atom forms a covalent bond with a host atom. Although the real bond length "A" between an impurity and a host atom in the crystal cannot be measured, it can be surmised from the bond length "a" between two atoms in a pure two-component crystal consisting of the elements same with the impurity atom and the host atom. The bond length between host atoms in the crystal is called standard bond length "a.sub.0 ". Definite and measurable bond length "a" replaces the real unknown bond length "A". The impurity whose replaced bond length "a.sub.1 " is shorter than "a.sub.0 " is called an under-impurity. The impurity whose replaced bond length "a.sub.2 " is longer than "a.sub.0 " is called an over-impurity.In this invention at least one under-impurity and at least one over-impurity are doped in the host single crystal. From the concentrations "x.sub.1 " and "x.sub.