Abstract: Modified natural graphite particles intended for forming a negative electrode material for a nonaqueous electrolyte secondary battery are characterized by having a circularity of at least 0.93 and at most 1.0 and a surface roughness of at most 1.5% with respect to the length of the particles. These modified natural graphite particles are obtained by a manufacturing method including a step of applying an impact force to natural graphite particles for pulverization and spheroidization to obtain intermediate particles having a circularity of at least 0.93 and at most 1.0, and a step of carrying out surface smoothing of the resulting intermediate particles by mechanical grinding treatment to obtain the modified natural graphite particles.

Abstract: A method capable of stably manufacturing a SiC single crystal in the form of a thin film or a bulk crystal having a low carrier density of at most 5×1017/cm3 and preferably less than 1×1017/cm3 and which is suitable for use in various devices by liquid phase growth using a SiC solution in which the solvent is a melt of a Si alloy employs a Si alloy having a composition which is expressed by SixCryTiz wherein x, y, and z (each in atomic percent) satisfy 0.50<x<0.68, 0.08<y<0.35, and 0.08<z<0.35, or ??(1) 0.40<x?0.50, 0.15<y<0.40, and 0.15<z<0.35.??(2) x, y, and z preferably satisfy 0.53<x<0.65, 0.1<y<0.3, and 0.1<z<0.3.

Abstract: A method capable of stably manufacturing a SiC single crystal in the form of a thin film or a bulk crystal having a low carrier density of at most 5×1017/cm3 and preferably less than 1×1017/cm3 and which is suitable for use in various devices by liquid phase growth using a SiC solution in which the solvent is a melt of a Si alloy employs a Si alloy having a composition which is expressed by SixCryTiz wherein x, y, and z (each in atomic percent) satisfy 0.50<x<0.68, 0.08<y<0.35, and 0.08<z<0.35, or??(1) 0.40<x?0.50, 0.15<y<0.40, and 0.15<z<0.35.??(2) x, y, and z preferably satisfy 0.53<x<0.65, 0.1<y<0.3, and 0.1<z<0.3.

Abstract: A SiC single crystal is produced by the solution growth method in which a seed crystal attached to a seed shaft is immersed in a solution of SiC dissolved in a melt of Si or a Si alloy and a SiC single crystal is allowed to grow on the seed crystal by gradually cooling the solution or by providing a temperature gradient therein. To this method, accelerated rotation of a crucible is applied by repeatedly accelerating to a prescribed rotational speed and holding at that speed and decelerating to a lower rotational speed or a 0 rotational speed. The rotational direction of the crucible may be reversed each acceleration. The seed shaft may also be rotated synchronously with the rotation of the crucible in the same or opposite rotational as the crucible. A large, good quality single crystal having no inclusions are produced with a high crystal growth rate.

Abstract: A SiC single crystal is produced by the solution growth method in which a seed crystal attached to a seed shaft is immersed in a solution of SiC dissolved in a melt of Si or a Si alloy and a SiC single crystal is allowed to grow on the seed crystal by gradually cooling the solution or by providing a temperature gradient therein. To this method, accelerated rotation of a crucible is applied by repeatedly accelerating to a prescribed rotational speed and holding at that speed and decelerating to a lower rotational speed or a 0 rotational speed. The rotational direction of the crucible may be reversed each acceleration. The seed shaft may also be rotated synchronously with the rotation of the crucible in the same or opposite rotational as the crucible. A large, good quality single crystal having no inclusions are produced with a high crystal growth rate.

Abstract: A joint for used in connecting oil well casing and/or tubing and method of producing same are disclosed. The joint with improved metal-to-metal sealing properties as well as improved resistance to galling is made of an alloy steel containing 10% or more by weight of Cr and comprises a metal sealing portion and a threaded portion provided with an activating layer of a metal or an alloy selected iron, nickel, zinc, cobalt, copper, manganese, chromium and alloys thereof, and an electrodeposited layer of a metal or an alloy selected from iron, copper, zinc, chromium, nickel, and alloys thereof.