管的

The welded pipe products is partitioned into five arrangements as per its characteristics and its six developing directions toward thin wall thickness,thick wall thickness,high accuracy,high grade,inside burr removal and anti-corrosion,etc.are analyzed.

我国中小直径焊管经过20世纪80~90年代的飞速发展，品种结构和应用领域已经有较大的改善，但是低压流体输送管、一般结构管比例较大，与焊管发达国家在锅炉、化工、油井、机械构件、高压流体输送用承压钢管和精密钢管领域不断扩大焊管的使用范围、提高高等级焊管使用数量方面存在一定的差距。

Furthermore, by using Natori theory on the field-effect transistor we study the current-voltage characteristics of deformed carbon nanotube field-effect transistors. For strain deformation, the conductivity of zigzag nanotube presents different characteristics with the remainder of n and 3. For armchair nanotubes, the conductivity does not change with the strain parameter. However, for torsion deformation, the conductivity rapidly increases, specially for the armchair tube. It has many obviously different conductivity behaviors between zigzag tubes and armchair tubes.

进一步应用场效应晶体管Natori理论模拟计算形变碳纳米管场效应晶体管的电流-电压特性的影响，zigzag碳管根据n 与3的余数关系表现出不同的电流变化趋势，而对于armchair碳管轴向拉伸不改变电流；在扭转形变时，碳管电流急剧升高，特别是armchair管。zigzag和armchair管的电流随扭转角度和外电压行为明显不同。

Barrel is the key part of artillery. In shot process, propellent gas of high pressure and high temperature flows in the tube at a high rate of speed, which brings an upheaval to the temperature field of the composite barrel. As to the composite barrel with metal inner, its poor thermal conductivity is more likely to cause uneven temperature distribution and bigger temperature gradient, to produce improper deformation and to make the work temperature of metal inner rise, all of which will affect the life span of barrel.

身管是火炮的关键部件，在火炮发射过程中，高温、高压的火药燃气在身管内成脉冲式高速流动，使身管受到急剧的加热，引起身管壁内的温度急剧变化，而对于带金属内衬复合材料身管，由于复合材料导热性能较差，更容易引起非均匀温度分布以及较大的温度梯度，产生不合适的变形，也会使身管的金属内衬的工作温度升高，从而使得身管的寿命降低，同时身管的发热会引起其刚度的变化，增大射弹散布。

The structure and morphology of CNTs which have been purified and not yet, were characterized by TEM, SEM, XRD, Raman, TG-DTA, BET, IR. The results indicated that when the stokehole reaction temperature was 1170℃,the decompose temperature of Ferrocene was 150℃,he volatilize temperature of Benzene was 50 ℃, hydric flow rate was 270ml/min, the concentration of thiophene was l% and the reaction time was 20 minutes, the CNTs with single-walled and multi-walled were prepared.

结果表明：炉膛反应温度1170℃、二茂铁的分解温度150℃、苯的挥发温度50℃、氢气的流量270ml／min、噻吩体积分数1.00／100ml苯、反应时间20min时，可以得到碳纳米管，既有单壁管又有多壁管，单壁管的内径分布在0.88～1.15nm之间，多壁管的直径分布在40～120nm之间；纯化后的碳纳米管比表面积增加，管壁光滑，而且产生了大量的含氧官能团，有利于在水溶液中的分散。

The structure and morphology of CNTs which have been purified and not yet, were characterized by TEM, SEM, XRD, Raman, TG-DTA, BET, IR. The results indicated that when the stokehole reaction temperature was 1170℃,the decompose temperature of Ferrocene was 150℃,he volatilize temperature of Benzene was 50 ℃, hydric flow rate was 270ml/min, the concentration of thiophene was 1% and the reaction time was 20 minutes, the CNTs with single-walled and multi-walled were prepared. The diameters of the single-walled CNTs are in the range of 0.08~1.15nm, and that of the multi-walled CNTs are in the range of 40~120nm.

结果表明：炉膛反应温度1170℃、二茂铁的分解温度150℃、苯的挥发温度50℃、氢气的流量270ml/min、吩体积分数1.00/100ml苯、反应时间20min时，可以得到碳纳米管，既有单壁管又有多壁管，单壁管的内径分布在0.881.15nm之间，多壁管的直径分布在40120nm之间；纯化后的碳纳米管比表面积增加，管壁光滑，而且产生了大量的含氧官能团，有利于在水溶液中的分散。

ResultsDistances between pyramidal eminence and chordal eminence and the facial canal were 3.22±0.41mm and 3.59±0.48mm, and length of the tympanic chorda posterior tubules was 9.44±1.65mm. Distances between pyramid segment of the facial canal and chordal eminence, lateral semicircular canal and posterior semicircular canal were 3.34mm±0.42mm, 1.54±0.25mm and 2.15±0.29mm, respectively.

结果颞骨标本解剖观察结果，锥隆起至鼓索隆起的距离（3.22±0.41）mm、锥隆起至面神经管直线距离（3.59±0.48）mm、鼓索后小管的长度（9.44±1.65）mm；面神经管锥曲至鼓索隆起间的距离（3.34±0.42）mm、面神经锥曲至水平半规管距离（1.54±0.25）mm、面神经锥曲至后半规管距离（2.15±0.29）mm。

The results show that increasing the ball numbers and mandrel extension length may reduce the ovalization, but leads to more remarkable wall thinning; the ovalization becomes more severe with the larger bending angle; the smaller the relative bending radius, the larger the ovalization is; the ovalization and wall thinning degrees are both smaller in the case of pressure die with dry lubricant; and under the same bending condition, the ovalization of LF2M tube is larger than the one of 1Cr18Ni9Ti tube.

结果表明，增加芯头个数与芯棒伸长量都能减小弯管的截面畸变，但两者都导致弯管壁厚减薄量增大；随着弯曲角度的增加，截面畸变越严重，相对弯曲半径越小，无芯棒与芯头支撑段弯管的截面畸变愈严重；在压块无润滑情况下，弯管的截面畸变和壁厚减薄量都小，并且在同等弯曲条件下，1Cr18Ni9Ti弯管的截面畸变小于LF2M弯管。

First, by the allocation of irrigation water directly into the ditch outlet Xiaqi, achieve no water loss, greatly improve the utilization of water; are two irrigation systems, replace the pipe with water furrow, not square, and the right to re-use, reducing the irrigation investment; Three is the use of the gate with the outlet opening to adjust a constant and accurate control of flow into the trench plot, for different soil and different groove specifications Xiaqi can greatly improve irrigation uniformity; four gates are porous pipe irrigation system for the flow tubes, and the blind to cross the flow tube as compared to the wall can reduce the work under stress, and reduce the damage to the opportunity to prolong the service life of thin-walled tube; are five gates to facilitate the installation of irrigation systems, pipes, and, upon request, to fight孔安outlet assembly to ensure the accuracy of positioning with the outlet.

一是灌溉水经配水口直接进入沟畦，实现无输水损失，极大地提高了水的利用率；二是管灌溉系统代替配水垄沟，不占地，且右重复使用，降低了灌溉投资；三是利用配水口的闸板开度来调节准确恒定地控制进入沟畦的流量，适用于不同土质和规格不同的沟畦，可大大提高灌水均匀度；四是闸管灌溉系统为多孔出流管，与等过流量的盲管相比，可降低管壁承受的工作压力，并减少受损机会，从而延长薄壁管的使用寿命；五是闸管灌溉系统安装方便，并可根据要求打孔安装配水口，确保配水口定位的准确性。

In accordance with the requirement of technical parameter of super high pressure bend and cold bend specification, the stress at cold bending on the three-roll bend machine was analyzed.

根据超高压弯管技术参数和冷弯工艺的要求，结合超高压管在立式三辊滚弯机上冷弯时的受力状态，运用弹塑性理论分析计算出弯管所用弯矩及弯管的最大压紧力，并据此选用弯管设备，解决了超高压弯管的制造问题。

During past 2 years, we produced milkly white fused quartz tubing, non-ozone quartz tubing, UV stop quartz glass tubing, sunshine quartz tubing on the basis of common quartz tubing, they are widely used in electric industry, electric lamp-house, chemical, nuclear industry, etc, and won users'trust and favorable comments .Our co. also holds advanced full analyse and finished product and detect system. The 2 sets of infrared photometers have being used in the process of producing, and control effectively the content of hydroxy in the quartz products.

公司成立两年多来，在生产普通石英管的基础上，相继推出乳白石英管、无臭氧石英管、滤紫外线石英管、以及太阳光石英管等，广泛用于电子工业、电光源、化学、核工业等领域，深受用户的信赖和好评。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。