Abstract: Novel hydantoin derivative which is represented by the formula: ##STR1## (wherein X and Y represent a halogen atom, R.sup.1 represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group or an alkynyl group, R.sup.2 represents a hydrogen atom, an alkyl group, an alkenyl group or an alkynyl group, and R.sup.3 and R.sup.4 independently represent a hydrogen atom or a lower alkyl group), and a herbicide containing said derivative as effective ingredient.This hydantoin derivative exhibit excellent weed-killing activity for harmful weeds and low phytotoxicity for crop plants.

Abstract: New L-phenylalanine dehydrogenases produced by a microorganism belonging to the genus Sporosarcina or Bacillus, new microorganisms capable of l-phenylalanine dehydrogenase and belonging to the genus Sporosarcina or Bacillus, a process for production of L-phenylalanine dehydrogenase using the microorganisms, and processes for production of L-amino acids using the enzymes or the microorganisms.

Abstract: Disclosed are novel oxazolidinedione derivatives expressed by the following formula: ##STR1## (R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 being defined in the specification), a method of producing the derivatives and herbicides containing the derivatives as an active ingredient.These novel derivatives exhibit excellent weed-killing activity for harmful weeds and low phytotoxicity for crops.

Abstract: A frequency-changeable microwave signal generator has a plurality of microwave signal oscillators, a plurality of branch lines connected to the microwave signal oscillators, a transmission line connected to the plurality of branch lines and provided with an output port at one end thereof, and a means for selectively operating one of the microwave signal oscillators. The line lengths of the branch lines are set such that the output impedance of the microwave signal oscillator connected thereto, which is measured from a branch point for connecting the transmission line and the branch line, is at maximum when the microwave signal oscillators are inoperative. The relation L=(.lambda./2)(k-1) (k is a natural number) is satisfied where L is a distance along the transmission line between adjacent branch portions of the branch lines connected to the transmission line, and .lambda. is a predetermined operational wavelength.

Abstract: A frequency converter includes a mixer, a local oscillator connected to the mixer by a line which transmits a local oscillator signal to the mixer and a starter circuit for supplying a transient bias current to the mixer for insuring the start of the local oscillations.

Abstract: A catalyst for isomerization consisting essentially of a salt or complex salt represented by the formula:[ML.sub.m ].sup.n+ [Y].sub.n.sup.- (I)where M is a metal of Group IB, IIA, IIB or VIII of the periodic table, L is a ligand, Y is a conjugated base of a Bronsted acid, m is 0, 1, 2, 3 or 4 and n is 1, 2 or 3.

Abstract: A microwave solid-state oscillator includes a casing hermetically enclosing a microwave oscillation device and a dielectric resonator electromagnetically coupled with the microwave oscillation device, an output terminal leading out an oscillation output from said casing, and a microwave terminal electromagnetically coupled to the dielectric resonator, one end of which is connected to a microwave line having a terminating admittance at the outside of the casing.

Abstract: A microwave power amplifier/combiner which is composed of .pi./2 hybrid coupler. This microwave power amplifier/combiner is constructed by associating a .pi./2 phase shifter with the .pi./2 hybrid coupler to form a 2-amplifier/combiner having a single input/output port and employing the 2-amplifier/combiner as one unit. 2.sup.N -amplifier/combiner can be constructed by employing a desired number of the unit 2-amplifier/combiner. According to this amplifier/combiner, the microwave power amplifier/combiner which combines the outputs of a large number of power amplifiers can be combined by employing a small number of .pi./2 hybrid coupler.

Abstract: A process for the production of an N-acyl-.alpha.-amino acid represented by the general formula ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4, independently from each other, represent a hydrogen atom, an alkyl or cycloalkyl group which may be substituted, or an aryl or heteroaromatic group selected from the group consisting of furyl, pyrrolyl, pyridinyl, thienyl and indolyl which may be substituted, which comprises reacting an oxirane represented by the general formula ##STR2## wherein R.sup.1 and R.sup.2 are as defined above, an amide compound represented by the general formulaR.sup.3 CONHR.sup.4 (III)wherein R.sup.3 and R.sup.4 are as defined above, and carbon monoxide in the presence of hydrogen, a cobalt-containing catalyst, and a promoter composed of a compound containing a metal selected from Groups I, II, III and IV of the periodic table.

Abstract: A microwave oscillation device of the invention comprises a cut-off waveguide having a cut-off characteristic with respect to a frequency used. At one end of this cut-off waveguide is provided a coaxial line member, at one end of which is provided a microwave absorber and at the other end of which is disposed an oscillation element. Within said cut-off waveguide is disposed a dielectric resonator so as to be electromagnetically coupled to the oscillation element of the coaxial line member in terms of lumped constant and to an output waveguide provided at the other end of the cut-off waveguide in terms of distributed constant.