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    【🔥做个时时彩平台多少钱】欢迎光临:传闻中的陈芊芊每周几更新

    2020-08-09 04:15:02

    《【🔥做个时时彩平台多少钱】欢迎光临》[37]

    The reader may notice how everything pertaining to patterns and moulding resolves itself into a matter of judgment on the part of workmen, and how difficult it would be to apply general rules.

    In using ruling pens, they should be held nearly vertical, leaning just enough to prevent them from catching on the paper. Beginners have a tendency to hold pens at a low angle, and drag them on their side, but this will not produce clean sharp lines, nor allow the lines to be made near enough to the edges of square blades or set squares.

    The invention is now complete, and as the principles are all within the scope of practical mechanism, there is nothing left to do but to devise such mechanical expedients as will carry out the principles laid down. This mechanical scheming is a second, and in some sense an independent part of machine improvement, and should always be subservient to principles; in fact, to separate mechanical scheming from principles, generally constitutes what has been called chance invention.

    An excellent plan to retain what is learned, is to make notes. There is nothing will assist the memory more in learning mechanics than to write down facts as they are learned, even if such memoranda are never referred to after they are made.

    Thumb-tacks are of but little use in mechanical drawing except for the most temporary purposes, and may very well be dispensed with altogether; they injure the draughting-boards, obstruct the squares, and disfigure the sheets.

    The importance of standard dimensions, and the effect which a system of gauging may have in the construction of machines, will be a matter of some difficulty for a learner to understand. The interchangeability of parts, which is the immediate object in employing gauges, is plain enough, and some of the advantages at once apparent, yet the ultimate effects of such a system extend much farther than will at first be supposed.

    Assuming, for example, that a machine will cost as much as the wages of an attendant for one year, which is not far from an average estimate for iron working machine tools, and that interest, wear, and repairs amount to ten per cent. on this sum, then the attendance would cost ten times as much as the machine; in other words, the wages paid to a workman to attend a machine is, on an average, ten times as much as the other expenses attending its operation, power excepted. This assumed, it follows that in machine tools any improvement directed to labour saving is worth ten times as much as an equal improvement directed to the economy of first cost.Arrangement comes next; in this the first matter to be considered is convenience of manipulation. The cutting position should be so arranged as to admit of an easy inspection of the work. An operator having to keep his hand on the adjusting or feed mechanism, which is about twelve inches above the work, it follows that if the cutting level is four feet from the floor, and the feed handle five feet from the floor, the arrangement will be convenient for a standing position. As the work requires continual inspection and hand adjustments, it will for this reason be a proper arrangement to overhang both the supports for the rack and the cutting tools, placing them, as we may say, outside the machine, to secure convenience of access and to allow of inspection. [156] The position of the cutting bar, crank, connections, gearing, pulleys, and shafts, will assume their respective places from obvious conditions, mainly from the position of the operator and the work.

    A solid milling cutter must be an accurately finished piece of work, made with more precision than can be expected in the work it is to perform. This accuracy cannot be attained by ordinary processes, because such tools, when tempered, are liable to become distorted in shape, and frequently break. When hardened they must be finished by grinding processes, if intended for any accurate work; in fact, no tools, except gauging implements, involve more expense to prepare, and none are so liable to accident when in use.

    Institute of Plasma Physics, Hefei Institutes of Physical Science (ASIPP, HFIPS) undertakes the procurement package of superconducting conductors, correction coil, superconducting feeder, power supply and diagnosis, accounting for nearly 80% of China's ITER procurement package.

    "I am so proud of our team and it’s a great pleasure for me working here," said BAO Liman, an engineer from ASIPP, HFIPS, who was invited to sit near Chinese National flay on the podium at the kick-off ceremony to represent Chinese team. BAO, with some 30 ASIPP engineers, has been working in ITER Tokamak department for more than ten years. Due to the suspended international traveling by COVID-19, most of the Chinese people who are engaged in ITER construction celebrated this important moment at home through live broadcasting.

    One of ASIPP’s undertakes, the number 6 poloidal field superconducting coil (or PF6 coil) , the heaviest superconducting coil in the world, was completed last year, and arrived at ITER site this June. PF6 timely manufacturing and delivery made a solid foundation for ITER sub-assembly, it will be installed at the bottom of the ITER cryostat.

    Last year, a China-France Consortium in which ASIPP takes a part has won the bid of the first ITER Tokamak Assembly task, TAC-1, a core and important part of the ITER Tokamak assembly.

    Exactly as Bernard BIGOT, Director-General of ITER Organization, commented at a press conference after the ceremony, Chinese team was highly regarded for what they have done to ITER project with excellent completion of procurement package.

     

    The kick-off ceremony for ITER assembly (Image by Pierre Genevier-Tarel-ITER Organization) 

     

    the number 6 poloidal field superconducting coil (Image by ASIPP, HFIPS) 

      

    ITER-TAC1 Contract Signing Ceremony (Image by ASIPP, HFIPS)

    World dignitaries celebrate a collaborative achievement

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