Abstract: A heterojunction field effect transistor has a high forward withstand voltage between a gate and a source, and includes a channel layer, a carrier supply layer, a first Schottky contact layer preferably made of AlGaAs, a second Schottky contact layer which preferably made of AlGaAs having an Al component ratio that is lower than that of the first Schottky contact layer, and a contact layer, which are disposed in that order on a semiconductor substrate. A groove is formed by removing a portion of the contact layer. A gate electrode extending from a region on a portion of the surface of the second Schottky contact layer to the surface or the inside of the first Schottky contact layer is formed in the groove. Accordingly, the Schottky barrier height is increased, and a high forward withstand voltage between the gate and the source is achieved. In addition, since the distance between the gate electrode and the channel layer is decreased, a high mutual conductance is achieved.

Abstract: A computer system comprising a server computer and a network computer operating upon downloading programs and data necessary for data processing from the server. The network computer comprises a local storage device in which at least a part of resources including the programs and data stored in a file system of the server are stored as a replica, determination means for determining a connection state to the server, and file system allocation means for selectively allocating the file system of the server and a local file system stored as a replica in the local storage device to the network computer in accordance with the determination result made by the determination means so that a common file access pass to both the file system of the server and the local file system of the local storage device can be used.

Abstract: The present invention provides a color display system characterized in that polarized surface control means comprises a ferro-electric liquid crystal cell, and a spacer and adhesive layer is interposed between a first panel and a second panel, the spacer and adhesive layer substantially setting a gap d between the first and second panels holding the ferroelectric liquid crystal therebetween to electrically drive the same to: ##EQU1## wherein: .lambda.: specific wavelength.DELTA.n: refractive index anisotropyd: gap (thickness of a liquid crystal layer).

Abstract: Novel sytrene resin compositions, especially styrene-acrylonitrile resin and styrene-acrylonitrile-butadiene resin compositions, are provided, which comprise a styrene resin having blended therein as lubricant at least one of the compounds represented by the following general formula: ##EQU1## wherein R and R' each represent hydrogen or a straight chain, saturated alkyl radical, the sum of the carbon atoms in both radicals R and R', being 14-42.This application is a division of application Serial No. 376,318, filed July 5, 1973, now U.S. Pat. No. 3,883,464, which in turn is a continuation-in-part of application Ser. No. 212,787, filed Dec. 27, 1971, now U.S. Pat. No. 3,817,900.