Abstract: In a current-source circuit in which a first and a second MOS field-effect transistor form a current mirror circuit, wherein a reference current can be supplied to the first MOS field-effect transistor via a third MOS field-effect transistor connected in cascode and the drain electrode of a fourth MOS field-effect transistor connected to the second MOS field-effect transistor in cascode forms an output, the source electrodes of the third and of the fourth MOS field-effect transistors are connected to inputs of an automatic gain control amplifier whose output is connected to the gate electrode of the fourth MOS field-effect transistor. The fourth MOS field-effect transistor is an extended-drain MOS field-effect transistor. The drain electrode and the gate electrode of the fourth MOS field-effect transistor are connected to one another via a further MOS field-effect transistor whose gate electrode is acted on by an operating voltage for the circuit.

Abstract: In a current-source circuit in which a first and a second MOS field-effect transistor form a current mirror circuit, wherein a reference current can be supplied to the first MOS field-effect transistor via a third MOS field-effect transistor connected in cascode and the drain electrode of a fourth MOS field-effect transistor connected to the second MOS field-effect transistor in cascode forms an output, the source electrodes of the third and of the fourth MOS field-effect transistors are connected to inputs of an automatic gain control amplifier whose output is connected to the gate electrode of the fourth MOS field-effect transistor. The fourth MOS field-effect transistor is an extended-drain MOS field-effect transistor. The drain electrode and the gate electrode of the fourth MOS field-effect transistor are connected to one another via a further MOS field-effect transistor whose gate electrode is acted on by an operating voltage for the circuit.

Abstract: Magnetic recording media consist of a nonmagnetic substrate and one or more magnetizable layers bonded thereon and based on a polyurethane binder, the binder consisting of not less than 50% by weight of a branched polyurethane elastomer having sulfonate groups and possessing urea groups at the chain ends.

Abstract: For intermediate enrichment of trace substances from a gas stream, a cold ap is used which carries a flow and optionally contains an adsorbent material and which is surrounded by a gas-tight double-walled jacket into which cooling fluid from a surrounding cooling bath can penetrate via an extension tube at the bottom. For desorption, the cooling fluid is expelled from the double-walled jacket via compressed air and a valve control. A pipe loop connected to the double-walled jacket and having a heater winding and circulation pump allows rapid heating of the cold trap. A level control apparatus connected to the compressed-air line allows sensitive level adjustment in the bottom extension tube of the double-walled jacket during the desorption phase. Such a cold trap is advantageous, inter alia, in a chromatography arrangement with a separation column and fractionating column of high resolution and sensitivity.

Abstract: Samples of trace substances are cryogenically concentrated by passing a gas sample through a U-bend immersed in liquid nitrogen. The U-bend is surrounded by a chamber wall and the chamber is vented so that liquid nitrogen can rise into the chamber when the vent is open but is driven out when the vent is closed and the enrichment pipe is heated to desorb the accumulated trace substances from the adsorbent in the enrichment pipe.