Abstract: A computer network which uses a community wiring for TV or wired broadcast and which is hardly influenced by disconnection, short-circuit and noise. The network is a coaxial cable network (1) which can transmit a mixed signal of the received signal of a receiver and a digital signal modulated into an RF signal. This coaxial cable network is provided with a signal input unit (2) for inputting a received signal into the coaxial cable network, and receivers (3a to 3c) and computers (4a to 4c) are connected with the coaxial cable network. Between the coaxial cable network and the computers, there are connected computer connection units (5a to 5c) for modulating a digital signal into an RF signal and for demodulating the RF signal into the digital signal.

Abstract: A unit which processes multiple signals transmitted through utility wiring by receiver/LAN has a utility wiring connecting terminal (10) connected to the utility wiring by receiver/LAN, at least one input-output terminal for connecting computer (11) connected to the terminal (10), and at least one input-output terminal for connecting receiver (12) connected to the terminal (10). First signal interference preventing circuits (13 and 19) are respectively connected between the terminal (10) and the input-output terminal (12) so as to check the reverse flow of LAN signals. Therefore, signals for a television receiver, etc., and LAN signals can be transmitted through a coaxial cable for television, etc., wired in an already existing building without causing interference between the signals.

Abstract: An internal composite layer for a multilayer circuit board, which is composed of an electrically insulating substrate with a copper layer formed thereon and a film of a coupling agent covering the copper layer is fabricated in accordance with the following method. That is, the copper layer is treated with a base or the base and an accelerating agent to supply hydroxyl groups to a surface thereof. Subsequently, thus treated copper layer is coated with the coupling agent, e.g., a silane coupling agent. The coupling agent is chemically bonded to the treated copper layer by the reaction of the hydroxyl groups with the coupling agent, so that an adhesion strength between the copper layer and the coupling agent is remarkably increased. In addition, since it is not necessary for forming a copper oxide layer in the surface of the copper layer, the internal composite layer shows excellent acid resistance without causing a pink-ring which usually occur around a through-hole plating.

Abstract: A packing material for reversed phase chromatography, which comprises silica gel with its entire surface substantially coated with repeating units of a polycarbosilane of the formula (I): ##STR1## wherein R.sub.1 is an octyl group, an octadecyl group or a phenyl group, R.sub.2 is a methyl group or a methylene group, and n is a positive integer.