Abstract: This invention relates to a chopped strand mat and a thermoplastic sheet for the manufacture of molded articles which are excellent in strength, rigidity and impact resistance as well as in color quality.The chopped strand mat according to the invention comprises chopped strands having fiber lengths of 10 to 100 mm and doped with a surface treating composition comprising an expoxysilane coupling agent and an epoxy resin and, as a binder, a polymer containing an acrylic ester unit. The thermoplastic sheet according to the present invention comprises the chopped strand mat impregnated with a thermoplastic resin.

Abstract: A ring-supported quartz crystal resonator having a circular peripheral surt region encircling an inner resonator region which is configured in the form of a domed arch wherein the top and bottom surfaces thereof are, respectively, convex and concave. In one embodiment the radius of curvature of the convex and concave top and bottom surfaces are substantially equal so that an arch of substantially uniform thickness is provided. In a second embodiment, the convex and concave top and bottom surfaces have different radii of curvature and, more particularly, the radius of curvature of the top surface is less than the radius of curvature of the bottom surfaces whereby a thickness of the inner region gradually increases uniformly toward the center. Such structures exhibit low resistance and improved mode spectrum.

Abstract: A new family of stress compensated quartz resonators having cuts exhibiting an ultra-linear frequency vs. temperature characteristic. This family of resonators has an orientation defined with respect to the crystallographic axes by polar angles .phi. and .theta., which angles lie on the locus where the second-order temperature coefficient of frequency is zero between the angles .phi.=20.degree..+-.2.degree. and .theta.=20.degree..+-.5.degree., and in close proximity to the locus of zero coefficient of stress. In one preferred embodiment, the resonator comprises a plate whose angles of cut .phi. and .theta. are both substantially equal to 20.degree.. In a second preferred embodiment an exact stress compensation is provided where .phi. is substantially equal to 20.8.degree. and .theta. is substantially equal to 23.2.degree., and orientation where the locus of the zero coefficient of stress intersects the locus of the zero of the second-order temperature coefficient.