时轴

Gaussmeters and fluxgate magnetometers with a computerized data collection system, enables us to

直流磁场测试时，采用三轴高斯计和磁门磁力仪与计算机数据采集系统，使我们能够以更有效的服务于

A shaft must have adequate torsion al strength to transmit torque and not be overstressed.

为了在传递扭矩时不发生过载，轴应该具有适当的抗扭强度。

For example, the pyramid shaped protrusions 136 may be selected when both rotational and axial forces are encountered.

例如，在遇到转动力和轴向力时，可选择金字塔形突出部136。

When Ta =550-590℃, the alloy is at the recrystallisation procedure, the microstructure turns to the unstrained equi-axed grains, and the recrystallisation temperature of the alloy is about 570℃.

Ta =550-580℃时，为再结晶阶段，纤维组织逐渐变成无畸变等轴晶粒，再结晶温度在570℃左右。

The results show that the plasticity zone and dynamically quiescent layer become fine equiaxed recrystallisation under the thermo-mechanical effect, the grains in the heat-affected zone grow up because of the effect of friction heat. When the rotation speed is 2 500 r/min and the welding time is 12 s, good joint is achieved, and the tensile shear strength of the joint reaches 9.24 kN. The tensile shear strength of spot increases with increasing tool rotation speed, with increasing welding time, the strength increases first, while then reduces. The microhardness of plasticity zone is high, but is slightly lower than that of the base metal, the minimum value of microhardness is in the heat affected zone. When the energy input of joint is high, the fracture type of spot is mode Ⅰ, and the tensile shear strength is high; on the contrary, when the energy input of joint is less the fracture type of spot is mode Ⅱ, and the strength is low.

结果表明：塑性区和动态静止层的晶粒在热和力作用下发生动态再结晶形成细小的等轴晶，热影响区的晶粒在摩擦热作用下长大变粗；搅拌头旋转速度为2 500 r/min，焊接时间为12 s时，可以获得力学性能较好的焊点，焊点的剪切强度达到9.24 kN；焊点的剪切强度随搅拌头旋转速度的增大而增大，随焊接时间的延长先增大后减小；塑性区的显微硬度较高，但略小于母材，接头显微硬度的最小值分布在热影响区；焊点热输入量较多时，接头为Ⅰ型断裂，焊点的剪切强度较高；焊点热输入量较少时，接头为Ⅱ型断裂，焊点的强度较低。

The rotary connection can be carried out in free space and hi-direction transmission of optical signal can be performed. Through analyzing the design principle of the optical structure and optical path calculation, it is found that when the ratio between the focal lengths for two lens is 20~50 and off-axis distance is in the range of 4~10mm, the interference will not be occurred between two optical channels and signal transmission can be lasted.

在自由空间可以实现旋转连接并实现光信号的双向传输，通过分析该光学结构设计原理和光路计算，发现每组透镜中两个透镜焦距之比为20-50，离轴距离为4-10mm范围时，才能保证光通道之间不发生干扰且信号持续传输。

Using fluid dynamics FEM (two dimensional, three dimensional andaxisymmetric) and three dimensional acoustic FEM in meticulous analysis ofexpansion muffler structure, this paper studies the influences of each mufflercomponents' position, dimension, form and quantity on the fluid dynamic andacoustic performances;therefore the paper indicates that the end of the intruding tubeis the linchpin of the fluid dynamic performance of the whole muffler structure, thespringhead of muffler fluid dynamic performance is the smoothness of air current, themain factor which affects the acoustic attenuation value of expansion chamber muffleris the grade of saltation of the section of air conducting access, and the attenuationvalue of specific frequency can be dramatically enhanced by carefully designing thelength of expansion chamber.

本文通过流体力学有限元方法和三维声学有限元方法对扩张腔消声结构的参数化模型进行了细致的分析，研究了这种结构的各个组成部份的位置、大小、形状和数量对其流体力学与声学性能的影响，指出插入管端口是影响整个结构流体力学性能的关键，消声结构流体力学性能的根源是气流通过时的平稳程度；影响扩张腔消声量的主要因素为声波传播通路截面突变的程度，并可以通过精细的设计扩张腔轴向长度获得宽频或指定频率消声量的大幅度提高。

Using a systematic approach and the concept of ＂pure HOLZ case＂ for electron diffraction,the convergence of the conventional multislice methodand the second-order multislice methodfor calculating higher-order Laue zoneeffects was studied.

高能入射电子与样品的体周期较长，或当晶体较大地偏离带轴时，HOLZ衍交互作用是一个复杂的电子弹性和非弹性散射过射束都会有较大的强度，此时，HOLZ衍射不能忽程。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失