摘要:
A plane antenna comprises a stack of a radiator circuit, first and second power supply circuits and earthing conductor member which are disposed independent of one another with dielectric layers respectively interposed between them, wherein patch elements of the radiator circuit which are respectively disposed in each of slots made in the circuit are electromagnetically coupled to power supplying terminals of the both power supplying circuits rather than directly connecting them, whereby the radiator circuit and power supply terminals are freed from the necessity of direct connection between them as well as the impedance matching between them, so as to eventually improve the assembling ability to a large extent.
摘要:
The present invention provides a vitreous silica crucible which can suppress the sidewall lowering of the crucible under high temperature during pulling a silicon single crystal, and a method of manufacturing such a vitreous silica crucible. The vitreous silica crucible 10 includes an opaque vitreous silica layer 11 provided on the outer surface side of the crucible and containing numerous bubbles, and a transparent vitreous silica layer 12 provided on the inner surface side. The opaque vitreous silica layer 11 includes a first opaque vitreous silica portion 11a provided on the crucible upper portion, and a second opaque vitreous silica portion 11b provided on the crucible lower portion. The specific gravity of the second opaque vitreous silica portion 11b is 1.7 to 2.1, and the specific gravity of the first opaque vitreous silica portion 11a is 1.4 to 1.8, and smaller than that of the second opaque vitreous silica portion. The particle size distribution of the material silica powder for the first opaque vitreous silica portion 11a is wider than that of the second opaque vitreous silica portion 11b, and the material silica powder for the first opaque vitreous silica portion 11a includes more fine powder than that for the second opaque vitreous silica portion 11b.
摘要:
A method of manufacturing a vitreous silica crucible by a rotary mold method, which includes performing arc melting in a state in which electrodes are provided so as to be shifted from a mold central line, wherein, by this eccentric arc, the glass temperature difference during melting of a straight body portion, a curved portion and a bottom of the crucible is controlled to 300° C. or below and the thickness of a transparent layer of the straight body portion and the bottom is controlled to 70 to 120% of the thickness of a transparent layer of the curved portion.
摘要:
A method of manufacturing a vitreous silica crucible by a rotary mold method, which includes performing arc melting in a state in which electrodes are provided so as to be shifted from a mold central line, wherein, by this eccentric arc, the glass temperature difference during melting of a straight body portion, a curved portion and a bottom of the crucible is controlled to 300° C. or below and the thickness of a transparent layer of the straight body portion and the bottom is controlled to 70 to 120% of the thickness of a transparent layer of the curved portion.
摘要:
A method for manufacturing a quartz glass crucible has a deposition step of depositing quartz powder on an inner wall surface of a bottomed cylindrical mold, while rotating the mold, and a melting step of obtaining the quartz glass crucible by vitrifying the quartz powder deposited on the inner wall surface of the mold by heating and melting the quartz powder. In the deposition step, under a state where the quantity of electrostatic charge of the quartz powder is controlled to be within a range of 1.0 kV or below in absolute value, the quartz powder is applied to the inner wall surface of the mold, and the thickness of the quartz glass crucible is controlled by maintaining the density of the quartz powder deposition layer on the inner wall surface of the mold within a fixed range.
摘要:
A crucible has a structure where a layer containing a crystallization accelerating component such as aluminum or the like (a crystallization accelerating layer) is inserted inside a quartz glass layer of a crucible straight body part excepting a crucible bottom part. The crucible does not deform and fall inwardly at the straight body part since a part containing a crystallization accelerating component advances to crystallize so as to increase strength at a high temperature when the crucible is used in pulling up silicon single crystal. Therefore, a single crystallization rate can be increased. Further, since the crystallization accelerating layer is inserted inside the quartz glass layer, the crystallization accelerating component, such as aluminum or barium, does not contact with silicon melt or a carbon susceptor, contamination by eluting these metals does not occurs. Further, since the crystallization accelerating layer is not provided at the crucible bottom part, there is no danger to crack due to thermal distortion at a time of pulling up silicon single crystal and melt leakage does not occur.
摘要:
A evaluation process of a vibration level at the surface of silicon melt held in a silica glass crucible is provided by setting in the vacuum furnace, the test piece of the silica glass cut out from a silica glass crucible, melting a little amount of silicon put on said piece of the glass, and measuring a vibration cycle of the silicon melt. Moreover, a silica glass crucible not causing the vibration at the surface of the silicon melt held in the silica glass crucible is also provided, wherein the vibration cycle of a silica glass of a side wall of the crucible is controlled at more than ⅙ seconds.
摘要:
A shock absorbing vehicle body structure in a vehicle includes a substantially quadrilateral front subsidiary frame comprised of left and right side members extending in a longitudinal direction of a vehicle body and connected at their front and rear ends to each other by a front cross member and a rear cross member. The front subsidiary frame is supported at its four corners on main frames for the vehicle body through rubber mounts and bolts. Upon full-lap collision of the vehicle, the left rear bolt is first broken, whereby the rear end of the left side member is separated from the main frame and then, the right rear bolt is broken, whereby the rear end of the right side member is separated from the main frame. The right and left side members are formed with different rigidities to a longitudinal load applied thereto, which causes the right and left rear bolts to break at different times, or with a time lag therebetween. Such a time lag decreases the peak value of deceleration of the vehicle at a time when the front subsidiary frame is separated from the main frames due to a full-lap collision of the vehicle.
摘要:
At least the first chamfered portion 22 for forming the apex portion 8 has a surface roughness (R.sub.p-p) of 0.6 .mu.m or under. This first chamfered portion 22 is formed through grinding with a #2500 or #1500 grinding stone.
摘要:
Provided is a vitreous silica crucible for pulling silicon single crystals, which can melt a silicon raw material in a short time and improve production yield of silicon single crystals by temporal change of an opaque vitreous silica layer. The vitreous silica crucible includes an opaque vitreous silica layer(11) provided on an outer surface thereof and containing plural bubbles, and a transparent vitreous silica layer(12) provided on an inner surface and not containing bubbles substantially. The opaque vitreous silica layer(11) has a bubble diameter distribution in which the content of bubbles having a diameter of less than 40 μm is 10% or more and less than 30%, the content of bubbles having a diameter of 40 μm or more and less than 90 μm is 40% or more and less than 80%, and the content of bubbles having a diameter equal to or more than 90 μm is 10% or more and less than 30%. Relatively small bubbles contained in the opaque vitreous silica layer(11) contribute to the thermal conductivity of a crucible at an initial pulling stage, and relatively large bubbles contained in the opaque vitreous silica layer are expanded through a long-term pulling process to thereby largely contribute to the warmth retaining property of the crucible at a later pulling stage.