摘要:
An aluminum nitride powder obtained by firing and reacting a mixture of alumina and carbon in a nitrogen-containing atmosphere is disclosed, the aluminum nitride powder having an oxygen content of not more than 2.0% by weight, an iron content of not more than 20 ppm, a silicon content of not more than 100 ppm, and a titanium content of not more than 20 ppm and having has a tapped density of at least 1.0 g/cm.sup.3. An aluminum nitride powder containing from 0.01% to 10% by weight of a sintering aid is also disclosed, the aluminum nitride powder having an oleophilic surface and having a tapped density of at least 1.0 g/cm.sup.3. The aluminum nitride powder of the present invention has excellent moldability, has a high tapped density, is less in formation of coagulated particles, and has a sharp particle size distribution.
摘要:
In a furnace which allows a feed powder or granules in a stack of trays on a base plate to be reacted with a reactive gas, the improvement wherein each of the trays has a cutout or an opening providing a passage for the reactive gas or the produced gas both at the top of one side wall and in the bottom wall to the opposite side of the tray, the base plate having an opening through which the reactive gas is introduced or the produced gas is discharged.
摘要:
When an abrasive having an oleophilic surface intended for use in magnetic recording media, said abrasive being obtained by subjecting an inorganic powder material having a Mohs hardness of 5 or above and an average particle size of 2 .mu.m or below to a wet contact treatment with an aqueous solution or an organic solvent solution containing a dispersing agent having an oleophilic group and drying the treated powder material, is used together with a magnetic powder material in the magnetic recording layer of a magnetic recording medium, the wear of the magnetic head can be prevented and the still characteristics of the recording medium is improved.
摘要:
A method for producing .alpha.-form silicon nitride having a central particle diameter of 0.3 to 1.0 .mu.m (.alpha.-Si.sub.3 N.sub.4) of high-grade and fine powder for its sintered body excellent in heat-stability and mechanical strength which comprises heat-treating at 1,450.degree.-1,550.degree. C., in an atmosphere containing nitrogen, a mixture prepared by adding one of additives:(a) a mixture of at least one of Be, Sr, Ge, Sn, Ti, Hf and compounds thereof with 0.01-1 part by weight of silicon nitride powder having a BET specific surface area of 15 to 50 m.sup.2 /g and consisting substantially of the .alpha.-form crystal, and(b) a mixture of Zr and compounds thereof with 0-1 part by weight of silicon nitride powder having a BET specific surface area of 15 to 50 m.sup.2 /g and consisting substantially of the .alpha.-form crystal,in a total amount of 0.001-0.1 part by weight calculated in terms of elemental weight(s) of Be, Sr, Ge, Sn, Ti, Hf and Zr and 1 part or less by weight of silicon nitride powder having a BET specific surface area of 15 to 50 m.sup.2 /g and consisting substantially of the .alpha.-form crystal, to 1 part by weight of silicon oxide powder of 1 to 100 .mu.m in central particle diameter and 0.4-4 parts by weight of carbon powder.
摘要:
A method for producing a high-grade fine powder of .alpha.-form silicon nitride (.alpha.-Si.sub.3 N.sub.4) for use as sintered bodies excellent in heat-stability and mechanical strength which comprises heat-treating, in an atmosphere containing nitrogen, a mixture prepared by adding additive:a mixture of at least one of Mg, Ca, and compounds thereof with 0.01-1 part by weight of silicon nitride powder,in a total amount of 0.001-0.1 part by weight calculated in terms of elemental weight(s) of Mg or/and Ca, and 1 part or less by weight of silicon nitride powder, to 1 part by weight of silicon oxide powder and 0.4-4 parts by weight of carbon powder.
摘要翻译:一种制造用作热稳定性和机械强度优异的烧结体的α型氮化硅(α-Si 3 N 4)的高级细粉末的方法,包括在含氮气氛中热处理由 添加添加剂:Mg,Ca及其化合物中的至少一种与0.01-1重量份氮化硅粉末的混合物,其总量为0.001-0.1重量份,以元素重量 Mg或/和Ca,1重量份或更少的氮化硅粉末,至1重量份氧化硅粉末和0.4-4重量份碳粉末。
摘要:
Disclosed is a method of fabricating rigid flexible PCBs. In the method, a self-detachable adhesive tape is used to separate a wafer and a substrate from each other in the course of conventionally fabricating a semiconductor wafer, is employed to avoid inherent problems occurring in the conventional method of fabricating rigid flexible PCBs.
摘要:
A focus control apparatus for a multilayer optical recording medium performs an adequate focus jump on a multilayer optical recording medium. Threshold values are set according to the amount of a level change in a focus error signal of a loaded multilayer optical recording medium, and focus jump control is conducted based on the result of comparison between the level of the focus error signal and the set threshold values. Positive and negative threshold values to be compared with the level of the focus error signal to detect a zero-crossing point of the focus error signal are set in accordance with the amount of a level change in the focus error signal, after which an acceleration operation of the focus actuator is started in response to a focus jump instruction to shift the focus position of read light for a focus jump, the acceleration operation is stopped in accordance with zero-crossing detection, a deceleration operation of the focus actuator is started thereafter and is stopped in accordance with zero-crossing detection, so that the operation returns to the focus servo operation.
摘要:
A fuel regulation apparatus of an engine for a model which is possible to regulate the flow rate of the fuel according to the rotational frequency of the engine is provided. A main body 31 of a fuel regulation apparatus 30 is provided with a fuel inlet 32, a fuel outlet 33, and an air inlet 42 to which air pressure from a crankcase is applied. The inlet 32 and the outlet 33 are connected therewith through a passage 34 having a seat face 37. A regulating valve 35 is placed in the passage 34 to close the seat face 37. A spring 38 pushes the regulating valve 35 in such a direction as to close the seat face. The other end of the regulating valve 35 is in contact with a piston 39. A position of an air inlet 42 can be adjusted by a screw 43. The spring pushes the piston 39 in such a direction as to open the seat face 37. The outlet 33 is connected to a fuel injection apparatus. The fuel injection apparatus injects the fuel into a crankcase. The piston is pushed according to air pressure in the crankcase 8 corresponding to rotational frequency and the seat face is opened. The flow rate can be controlled according to the rotational frequency of the engine. The fuel which is apt to be insufficient at the time of high speed can be increased and the fuel which is apt to be dense at the time of low speed can be throttled.
摘要:
Fuel to which a predetermined pressure is applied is supplied to an electronically controlled fuel injection system of a engine for models in order to improve the rotation stability during low speed operation and the response to rapid acceleration or deceleration. The pulsatory air pressure is generated in a crank chamber of a engine for models during operation. An air pressure intake guide 51 of a fuel pressure control valve 1 receives air pressure from the crank chamber. The air intake guide is provided with an excessive pressure leak valve the actuation pressure of which is adjustable. The air pressure intake guide communicates with interposition of a check valve 56 to a controlled air pressure supply passage 54 which communicates to a fuel tank. The check valve 56 supplies the positive pressure of the pulsatory air pressure from the controlled air pressure supply passage to the internal of the fuel tank. All the positive air pressure supplied to the air pressure intake guide 51 is supplied to the fuel tank when the pressure in the fuel tank is below a specified pressure. The air pressure supplied to the air pressure intake guide 51 actuates a control ball 60 of the excessive pressure leak valve 57 and is released to the outside. The check valve 56 prevents the air pressure in the fuel tank from flowing inversely.
摘要:
An electronic equipment has a stick as a movable input device provided to be manually moved. The position of the stick is detected. In accordance with the detected position, the movement of the stick is restricted within a predetermined movable range so as to be moved a plurality of predetermined areas. The area in which the stick is located is detected. In accordance with the detected area, corresponding control data stored in a memory are read out, and the electronic equipment is controlled by the read out control data.