中杆

There are two worn gear drive device of open-close and turn over on the worm gear blind cut-off valve gate. The gear rim, gear wheel and screw pole screw pairs of open-close worm gear box drive the right and left valve body to clamp and release. The turn-over worm gear box drives the valve disc to open. There is limit block on the valve disc to ensure the open-close position of the valve disc.

蜗轮传动盲板切断阀，阀门中设有启闭和翻转两个蜗轮传动装置，启闭蜗轮箱通过齿圈、齿轮和丝杆螺旋副驱动左、右阀体完成松开、夹紧动作，翻转蜗轮箱驱动阀板完成开启动作，阀板上设有限位挡块以保证阀板的启闭位置。

The main aim in this paper is the basic theory of the three screw pump.

于是在研究中主要是对三螺杆泵做基础理论的研究。

Stainless steel welding technology, stainless steel shot peening technology, large parts heat treatment technology, screw sleeve, textile machinery and electrical control system research and development in manufacturing technology, such as the textile machinery industry in a leading position.

不锈钢焊接技术、不锈钢喷丸技术、大型工件热处理技术、螺杆套筒、纺机电器控制系统研发及制造技术等在全国纺机行业中居领先地位。

The VCL method and the displacement method are used to calculate the Stress Intensity Factors of semi-elliptical surface crack at the root of pipe screws, on the basis of which a simplified calculating model for screws contact is put forward so as to analyse the fracture intensity for oil drill pipe screw coupling. For the semi-elliptical surface crack with different shape and deep ratio at the root of female and male screws and the corner of male flange, the SIF has been studied systemically under inter-pressure, tension, bend and torsion loads and the approximate formulas encluding the structure parameters of oil drill pipe screw coupling, deep ratio and the shape parameters of surface crack are developed.

对工程实际中的多种石油钻杆接头螺纹连接件，就公螺纹齿根、母螺纹齿根、公螺纹台阶转角处存在的不同形状、不同厚度比的半椭圆表面裂纹，在拉伸、内压、弯曲、扭转多种载荷作用下的应力强度因子作了系统研究，在大量有限元计算基础上，建立了包含接头结构参数、裂纹形状、厚度比在内的近似计算公式。

The concrete steps are: the lactic acid and small-molecule dicarboxylic acid react under the condition with the presence of the catalyst to directly polymerize the carboxyl-terminated lactic acid prepolymer; then the aliphatic polycarbonate diol and the catalyst are added; with the presence of the N2, the reaction is kept for 1 to 10 hours at the temperature of 150 to 200 Celsius system to get the poly lactic acid and polycarbonate copolymer of the low molecular weight; then the reaction is done in the twin-screw extruder at the temperature of 150 to 190 Celsius system to screw out the extension chain; finally the polylactic copolymer of the high molecular weight, toughness and heat resistance is made.

具体步骤是：乳酸和小分子二元酸在催化剂条件下反应直接缩聚合成羧基封端的乳酸预聚物，然后加入脂肪族的聚碳酸酯二元醇和催化剂，在N 2 气氛下，抽真空，在150～200℃温度下，反应1～10小时，得到低分子量聚乳酸/聚碳酸酯共聚物，然后在双螺杆挤出机中在140～190℃下，进行反应挤出扩链，最终得到高分子量的、韧性与耐热性较好的聚乳酸共聚物。

For valves with service above 550 psi (3795 kPa), an integral bonnet with a rod seal consisting of a pressure energized seal and a heavy duty braided scraper ring is required.

如果阀门应用在压力500 psi (3795 kPa)以上的应用环境中，则需要配置整体阀盖，带由一个压力自紧密封和一个重型编制平板环组成的杆密封。

In this thesis, we study the field-emission properties of individual CNTs systematically inside transmission electron microscope using the sample holder integrated with a scanning tunneling microscope.

本文在透射电子显微镜中，利用装有微型扫描隧道显微镜的样品杆对单根碳管的场发射性质做了较为系统的研究。

The problems about safety and durability of bolt and cable-supported structures are presented.

1引言 锚固类结构主要指锚索、锚杆和土钉一类岩土工程常用加固、支护结构，在非临时性工程中，还包含加筋土结构。

Alloy frame, Double Wall Alloy tire circle, Dishing brake, forging suspension front fork, Alloy adjustable handlebar stem with gears, alloy handle, alloy retroflex saddle tube, alloy adjustable rack, middle parking rack, Alum-plating electric mudgurads, alloy cranks, 1.75 glisten tires. SHIMANO 6-speed chains linker, SHIMANO gearlever, spring saddle,24V.9AH/13AH battery, intelligent meterplate, LED front and rear lights, 3-grade Electric Assist Driving System（1st,Bike;2nd,1:1 Standard Riding Pull-assist; 3rd,Strong Pull-Assist） 6-grade Manual speed changes,1.8A NiMH Battery chargerAlloy Power-cut Brake handle

描述： 6061#铝合金高强度车架，铝双层车圈、前碟刹、铝前花鼓、锻造铝合金减震前叉、有牙铝合金把立、铝合金把横、铝合金翻转鞍管、铝合金可调节衣架、中支撑、铝合金曲柄，镀铝导电型前后泥板、1.75反光轮胎、禧玛诺外6速拨链器、禧玛诺变速杆、弹簧减震坐垫、9AH/13AH镍氢电池、智能仪表盘、 LED照明前灯、后LED灯、三档电动助力驱动系统（一挡、自行车；二挡、1：1标准骑行助力；三挡、强助力）、6档机械变速、1.8A镍氢电池充电器、全铝断电刹车握把。

2 The provisions of valve flap stent thrust nut in space; 4.3 will bring more than ejector stem components, and into the valve flap bracket, now can adjust screw ring on the injector; adjustment ring discharge pipe may be twisted too high in case of this case, when the valve assembly after the valve flap in contact with its seat before the valve flap seat will have an additional load on the adjustment ring edge, in order to avoid this from happening, should enable the adjustment ring hole just below the injector thread, through which holes should not be able to see thread.

4.2 规定阀瓣支架与止推螺母中的间隙； 4.3 将喷射器提起超过阀杆组件，并放到阀瓣支架上，现在可以把调节环拧在喷射器上；调节环可能在排放管上拧得太高，如遇此情况，当阀门组装后，在阀瓣与其座相接触前，阀瓣座将加载荷于调节环的边上，为了避免此情况的发生，应使调节环上的孔正好低于喷射器的螺纹，通过这些孔应不能看到螺纹。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐