Abstract: A process for producing carbon fibers from various kinds of pitches wherein the calorific values of the pitches are measured and the pitches thereafter subjected to a suitable procedure for producing carbon fibers therefrom depending on their measured calorific value.

Abstract: A radioactive diagnostic agent which comprises a protein and a radioactive metallic element combined with intervention of a bifunctional chelating agent of the formula: ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are each a hydrogen atom or a C.sub.1 -C.sub.3 alkyl group and is characteristic in having high stability even after administered into a human body.

Abstract: A radioactive diagnostic agent which comprises a protein and a radioactive metallic element combined with intervention of a bifunctional chelating agent of the formula: ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are each a hydrogen atom or a C.sub.1 -C.sub.3 alkyl group and is characteristic in having high stability even after administered into a human body.

Abstract: A connection terminal construction for connecting a driving coil terminal of an electro-mechanical converter such as a step motor or the like of electronic timepieces to an output terminal of a wiring circuit is disclosed. The construction comprises a terminal base formed of a flexible print substrate and provided at least one of upper and lower surfaces thereof with connection patterns. The terminal base is extended toward a circuit substrate substantially in alignment therewith and secured thereto by means of a screw.

Abstract: A square-wave signal generator circuit for generating a rectangular waveform signal particularly for application to the field coil of an electromagnetic flow meter. A coil excitation current from a direct current source is switched to provide a current flow in alternate directions through the field coil. During the transient time of the coil excitation current following the switching operation, a higher output voltage from the source is used to shorten the current rise and fall times while a lower voltage from the source is used during a steady state time of the excitation current to minimize power losses. A switching circuit using a switching transistor is used to select the higher voltage while a back-biased diode is used to immediately introduce the lower voltage when the excitation current has reached a steady state.