Abstract: A charged-particle beam instrument is offered which can cancel out deflection aberrations arising from a first deflector or oblique incidence on the surface of a workpiece without (i) increasing the electrode length, (ii) reducing the inside diameter of the electrode, or (iii) increasing the deflection voltage too much. The instrument has an electron source for producing an electron beam, a demagnifying lens for condensing the beam, an objective lens for focusing the condensed beam onto the surface of the workpiece, the first deflector located behind the demagnifying lens, and a second deflector located ahead of the demagnifying lens. The first deflector determines the beam position on the surface of the workpiece. The second deflector cancels out deflection aberrations arising from the first deflector.

Abstract: There is disclosed an electrostatic deflector having four pillar-like identical electrodes spaced from each other by 90°. An even number of pillar-like electrodes are disposed in each space between the four electrodes. Spaces are formed on both sides of each one of the first electrodes and have bent portions. The even number of electrodes are arranged symmetrically relative to a third or fourth vertical plane including an axis spaced from the X-axis by 45° or ?45°, respectively. Holes are formed across each of the third and fourth vertical planes. Rod-like members are inserted in the holes.

Abstract: An FRP is produced using a prepreg comprising reinforcing fiber, a sheet-like reinforcing fiber substrate containing reinforcing fiber, and a matrix resin, wherein the matrix resin is impregnated into the sheet-like reinforcing fiber substrate and also covers one surface of the sheet-like reinforcing fiber substrate, and the matrix resin impregnation ratio is within a range of 35% to 95%; a prepreg comprising reinforcing fiber, a sheet-like reinforcing fiber substrate containing reinforcing fiber, and a matrix resin, wherein the matrix resin exists on both surfaces of the sheet-like reinforcing fiber substrate, and the portion inside the sheet-like reinforcing fiber substrate into which the matrix resin has not been impregnated is continuous; or a prepreg comprising reinforcing fiber, a sheet-like reinforcing fiber substrate containing reinforcing fiber, and a matrix resin, wherein at least one surface exhibits a sea-and-island-type pattern comprising resin-impregnated portions (island portions) where the mat

Abstract: An epoxy resin composition suitably used for a prepreg which can complete curing in a short time even at a low temperature and secure a sufficient usable period under preservation at room temperature, in comparison with conventional epoxy resin compositions. An epoxy resin composition comprising at least one of an epoxy resin, an amine compound having at least one sulfur atom in the molecule thereof, and a reaction product of an epoxy resin and an amine compound having at least one sulfur atom in the molecule thereof, and an amine compound having at least one sulfur atom in the molecule thereof, and a urea compound and a dicyandiamide, wherein each of the contents of the sulfur atom and the urea compound in the epoxy resin composition is respectively 0.2 to 7% by mass and 1 to 15% by mass.

Abstract: Epoxy resin compositions comprising (a) an epoxy resin, (b) a latent curing agent with curing power at 100° C. or below and (c) an aromatic amine-based curing agent and/or an alicyclic amine-based curing agent, which are curable in two stages, or epoxy resin compositions further comprising (d) a curing accelerator, as well as a prepregs comprising reinforcing fiber materials impregnated with the epoxy resin compositions. The compositions give die-releasable cured products by primary curing at low temperature, give highly heat-resistant cured products by secondary curing, and exhibit satisfactory stability at room temperature.

Abstract: A preform can be molded by resin transfer molding and yields a composite material having excellent strength and excellent interlaminar debonding resistance. The preform, which is for producing a fiber-reinforced composite, comprises layers of laminated structure of a reinforcing material comprising reinforcement fibers and has, between these layers, a layer comprising a thermoplastic resin and having space so as not to inhibit a liquid resin from flowing therethrough. The preform is molded to yield a fiber-reinforced composite material.

Abstract: A preform can be molded by resin transfer molding and yields a composite material having excellent strength and excellent interlaminar debonding resistance. The preform, which is for producing a fiber-reinforced composite, comprises layers of laminated structure of a reinforcing material comprising reinforcement fibers and has, between these layers, a layer comprising a thermoplastic resin and having space so as not to inhibit a liquid resin from flowing therethrough. The preform is molded to yield a fiber-reinforced composite material.

Abstract: Epoxy resin compositions comprising (a) an epoxy resin, (b) a latent curing agent with curing power at 100° C. or below and (c) an aromatic amine-based curing agent and/or an alicyclic amine-based curing agent, which are curable in two stages, or epoxy resin compositions further comprising (d) a curing accelerator, as well as a prepregs comprising reinforcing fiber materials impregnated with the epoxy resin compositions. The compositions give die-releasable cured products by primary curing at low temperature, give highly heat-resistant cured products by secondary curing, and exhibit satisfactory stability at room temperature.

Abstract: A drilling control apparatus for automatically controlling the drilling operation of a rock drill includes a control unit for storing known criteria drilling patterns for various rock properties. A specific drilling pattern is selected based upon a collaring procedure for operation of the rock drill. A detector continually monitors variables such as rotational pressure, feed pressure and flushing pressure during the drilling process to determine a change in condition of the rock for determination of automatic selection of another more appropriate drilling pattern.

Abstract: A prepreg for fiber-reinforced composite materials comprising (A) a reinforcing fiber having a modulus of elasticity of 200 GPa or more, (B) a fibrous thermoplastic resin having a modulus of elasticity of 100 GPa or less, and (C) a thermosetting matrix resin. The prepreg of the present invention does not only have excellent handling property equivalent to that of the prepreg with the conventional thermosetting resin as a matrix, but also gives excellent toughness to the resulting molded product without injuring the thermal and mechanical properties. Particularly, it has a high resistance to interlaminar fracture when exposed to impact, so that it is preferably used as a structural material for airplanes, etc.

Abstract: An epoxy resin composition used as a matrix for a fiber-reinforced composite is disclosed, which comprises the following components:(A) a bifunctional epoxy resin;(B) at least one of a trifunctional epoxy resin and a tetrafunctional epoxy resin;(C) a dihydroxybiphenyl compound represented by the following general formula: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4, which may be the same or different, each represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; and(D) an aromatic amine,wherein said components (A), (B), (C) and (D) are used in amounts satisfying the following conditions:1/0.1.gtoreq.a/b.gtoreq.1/1.210/1.gtoreq.(a+b)/c.gtoreq.1/11/0.8.gtoreq.(a+b-c)/d.gtoreq.1/1.5wherein a represents the molar number of epoxy groups in component (A), b represents the molar number of epoxy groups in component (B), c represents the molar number of phenolic OH groups in component (C) and d represents the molar number of NH groups in component (D).