Abstract: A two-component type dry developer consisting of a mixture of a toner and a magnetic carrier. The toner contains a resin as its main component. The magnetic carrier has a specific surface area of 100 to 300 cm.sup.2 /g and a shape factor of not less than 5.5.times.10.sup.-2 and less than 8.0.times.10.sup.-2. The product of flowability and true specific gravity of the magnetic carrier is 100 to 190 sec/50 g.

Abstract: This is one-component type dry developer for an electrophotography which is improved on humidification ability, and consists of mixture of toner with a particle size of 5.about.50 (.mu.) and hydrophobic flow agent. The flow agent is made by covering inorganic, organic, metallic or alloy powder with thin film of non-hydrophilic synthetic resin. By using electric conductive material as core and making a range of resin film thickness so as to cause tunnel effect of electron or ion, the flow agent which has non-hydrophilic property and electric conductive property is obtained.

Abstract: A microwave transmitting and receiving apparatus comprises a Gunn diode as an oscillating element and a mixer diode as a receiving element disposed within a rectangular waveguide closed at one end by its short-circuiting plate. The oscillating and receiving elements are juxtaposed with each other at a position spaced by 1/2 .lambda.g (.lambda.g: wavelength in the waveguide) from the short-circuiting plate toward an opening of the waveguide. An adjusting screw for permitting a match of the receiving element impedance with the input signal impedance and for adjusting the output power is fitted by screw engagement to the waveguide at a position spaced by 1/4 .lambda.g from a straight line connecting the both elements toward the waveguide opening, and another adjusting screw for oscillating frequency-adjustment is fitted by screw engagement to the waveguide at a position between said straight line and the short-circuiting plate.