Abstract: An optical beam scanning system for scanning photosensitive material (1) comprises a laser (201), a beam splitter (204) for producing multibeams (LB.sub.a, LB.sub.b), AOM's (207a, 207b), a multibeam adjuster (300) for turning the multibeams to intersect each other at a prescribed point (P.sub.C), a horizontal expander (211), an AOD (213), a vertical expander (214), a deflection direction adjuster (400) for rotating a deflection direction of the multibeams, and a variable focusing mechanism (500) comprising a plurality of object lenses (501-504). A pixel pitch and a spot diameter on the photosensitive material can be changed separately from each other by exchanging the object lenses and by adjusting an angle of intersection of multibeams (B.sub.a, B.sub.b) by means of the multibeam adjuster. Cylindrical lenses of the horizontal and vertical expanders are so positioned that they compensate a cylindrical lensing effect of the AOD.

Abstract: There are provided processes for the preparation of .gamma.-methacryloxypropylsilane compounds which comprise carrying out the reaction of allyl methacrylate with a hydrosilane compound in the presence of a platinum catalyst, while allowing at least one of a hindered phenol compound and an aromatic amine compound to coexist in the reaction system with an alkylamine compound or an amide compound, or with a gas containing molecular oxygen, or with a phenol compound having an aminoalkylene group. By using these processes as provided, gelation of the reaction mixture in the reaction system and during the course of purification thereof by distillation can effectively be avoided, and the desired .gamma.-methacryloxypropylsilane compounds can be obtained in good yield.

Abstract: An optical beam scanning apparatus includes a beam-to-beam distance adjuster (300) for rotationally displacing a beam splitter (301). The beam-to-beam distance adjuster (300) comprises three arm members (312, 313, 314) which are linked to each other through notch portions (323, 324). A member (315) is linked to the arm member (313). The beam splitter (301) is secured on the member (315) from which a plate spring (316) extends. A projection member (317) is provided between a leading edge portion of the plate spring (316) and the arm member (314). A rotation angle of the beam splitter (301) can be changed by actuating three arm members (312, 313, 314) in link motion, whereby a beam-to-beam distance between two beams (B.sub.a, B.sub.b) can be also changed.

Abstract: N-(.alpha.,.alpha.-dialkylbenzyl)-phenylacetamide compounds represented by the following general formula: ##STR1## wherein each of X.sub.1 and X.sub.2 is a halogen atom, an alkyl group containing from 1 to 3 carbon atoms, an alkoxyl group containing from 1 to 3 carbon atoms or a hydrogen atom; R.sub.1 is an alkoxyl group containing from 1 to 3 carbon atoms or a hydrogen atom; R.sub.2 is an alkyl group containing from 1 to 3 carbon atoms, and alkoxyalkyl group containing from 2 to 6 carbon atoms, an allyl group or a hydrogen atom; each of R.sub.3 and R.sub.4 is an alkyl group containing from 1 to 4 carbon atoms; and each of m and n is an integer of 1-3. This invention also provides herbicidal compositions comprising at least one of said compounds and a carrier.

Abstract: N-(.alpha.,.alpha.-dimethylbenzyl)-phenylacetamide compounds represented by the following general formula: ##STR1## wherein X is a chlorine atom or a bromine atom. This invention also provides herbicidal compositions comprising at least one of said compounds and a herbicidal carrier.

Abstract: N-(.alpha.,.alpha.-dialkylbenzyl)-phenylacetamide compounds represented by the following general formula: ##STR1## wherein each of X.sub.1 and X.sub.2 is a halogen atom, an alkyl group containing from 1 to 3 carbon atoms, an alkoxyl group containing from 1 to 3 carbon atoms or a hydrogen atom; R.sub.1 is an alkoxyl group containing from 1 to 3 carbon atoms or a hydrogen atom; R.sub.2 is an alkyl group containing from 1 to 3 carbon atoms, and alkoxyalkyl group containing from 2 to 6 carbon atoms, an allyl group or a hydrogen atom; each of R.sub.3 and R.sub.4 is an alkyl group containing from 1 to 4 carbon atoms; and each of m and n is an integer of 1-3. This invention also provides herbicidal compositions comprising at least one of said compounds and a carrier.