If , while exposed to the magnetic field , the precessing nuclei are also hit with a radiofrequency ( rf ) pulse , they will absorb and re - emit energy at specific frequencies according to their rate of precession 当暴露在外界磁场中的时候，旋进的原子核也会被射频脉冲击中，它们会吸收并且根据旋进率再释放特殊频率的能量。
The assemble criterion of sensor for design was advanced . at last , a method of increasing signal - to - noise ratio and reducing flux lower limit value of vortex flowmeter was advanced . the experiment program was advanced 针对旋进旋涡流量计的理论分析所存在的问题，论文应用fluent软件对该流量计进行了直接流场仿真研究，分析仿真的结果和误差，并提出了改善仿真精度的途径。
On the action of magneto mechanical coupling of rotating magnetic field generated by turning of exterior driver , robot was spun to generate propulsion in axial direction under the function of fluid dynamic pressure distributed on spiral surface of the robot , as a result , spiral and drive motion of the capsule type micro robot in intestine was realized 通过外驱动器的旋转产生旋转磁场，借助于磁机耦合作用，驱动机器人旋转并在其外螺纹表面形成的流体动压力作用下产生轴向推力，进而实现胶囊式机器人在肠道内旋进。
By comparing the results with relative experiment data , it is shown that rng k - is more exactly than the other turbulent model . . 2 ) the influences of axial inflow position , radial outflow size , rotating reynold number , non - dimensional mass flowrate and axial inflow angle on the flow and heat transfer characteristics were numerically investigated for a typical rotator - stator cavity with axial inflow , radial inflow and radial outflow . the correlations for average nusselt number vs rotating reynold number or non - dimensional mass flowrate were established ( 2 )针对一典型的径向、轴向进气，径向出气的转-静盘腔结构，系统研究轴向进气位置、径向出口大小、旋转雷诺数、无量纲质量流量和轴向垂直预旋进气等对盘腔内流动和换热的影响，整理出转-静盘腔内转盘平均努谢尔数与旋转雷诺数无量纲质量流量之间的准则关联式。
Applying too direct or too much force during the " catch " phase of the stroke - if during the " catch " phase of the stroke , too straight or too strong a force is used , the head of the humerus is rotated into the deltoid muscle and causes tendonitis , and / or the scapula is pushed against the rotator cuff muscles , causing pain or possible tissue damage 在划臂的“抓水”阶段，手臂径直抓水或过分用力一如果在划臂的“抓水”阶段，手臂太直或过分用力，肱骨头就会旋进三角肌引起肌腱炎，肩胛骨也会挤压轴转肌而引起肌肉疼痛或组织损伤。
Collapsing the elbow across the body during the underwater propulsive phase of the stroke - if the elbow is dropped during the propulsive phase of the stroke , the head of the humerus is , again , rotated into the deltoid causing friction and tedonitis , and / or the scapula is pushed against the rotator cuff muscles , causing pain or possible tissue damage 在划臂的“抓水”阶段，手臂径直抓水或过分用力一如果在划臂的“抓水”阶段，手臂太直或过分用力，肱骨头就会旋进三角肌引起肌腱炎，肩胛骨也会挤压轴转肌而引起肌肉疼痛或组织损伤。
In this work , a new dual triangulate bluff body vortex flowmeter was developed , the flux lower limit value of which lower by 50 % that of the old single bluff body vortex flowmeter . the linear correlation of the correlation between the velocity pressures of fluid disturbs wave and that of vortex precession in vortex precession flowmeter was brought to light , and a spectrum phase discrimination method based on fft to remove the effect of fluid pulsating interference on vortex precession flowmeter was advanced 研制出比传统单钝体涡街流量计流量下限降低约50的新型双钝体涡街流量计；揭示出脉动流中旋进旋涡流量计流体振动特性，并在此基础上提出基于fft相位判别的数字信号处理方法来消除流场脉动对旋进旋涡流量计的干扰的方法。
The main content of each chapter is as following . the first chapter at first generally introduced the history and the actuality of flowmeter on the basis of relevant publications search . one of most promising flowmeter - the vortex type fluid oscillatory flowmeter - was selected as research subject 有关各章内容分述如下：论文第一章以大量的国内外文献为基础，全面综述了流量计的发展历史和现状，确定以具发展前途的流量计之一? ?旋涡型流体振动型流量计(涡街流量计和旋进旋涡流量计)作为研究内容。
4 ) in a pre - swirl rotator - stator cavities with discrete pre - swirl nozzles and blade - cooling entry holes , the influences of pre - swirl angle and flow parameter on the flow and heat transfer characteristics were numerically investigated . the correlation for average nusselt number vs rotating reynold number or non - dimensional mass flowrate were established . the results show that : advantage of per - swirl inflow is the effect of cooling the blade - cooling entry holes ; pre - swirl inflow increases heat transfer in rotating disk of pre - swirl chamber ; as pre - swirl angle increases , local nusselt number decreases in pre - swirl chamber ; the temperature of stator of inner rotator - stator chamber and per - swirl chamber decreases as rotating reynold number increases ; when the axial mass flowrate maintains constant , heat transfer in the rotating disk of inner rotator - stator cavities does n ' t change as per - swirl mass flowrate increases , while heat transfer in the rotating disk of per - swirl chamber increases ; when the pre - swirl mass flowrate maintains constant , change of the axial mass flowrate has effect on the whole cavity 结果表明，预旋进气的优点在于增强了叶片冷却孔附近的对流换热效果，局部努谢尔数随预旋角的增大而有所减小；随旋转雷诺数的增加，不论是内转静腔室还是预旋腔室的静盘上的温度都不同程度的降低：当轴向中心进气质量流量不变时，随预旋进气的质量流量增加，内转静腔室的转盘盘面上的换热基本没有变化，而预旋腔室的转盘盘面上的换热效果增强；当预旋进气质量流量不变时，轴向中心进气的质量流量的改变对整个盘腔都有影响。
In the third chapter , the method and choosing principle of the test system component at first were brought out . the component of test device was introduced . and then , the characteristics , such as strouhal number , vortex street strength , vortex street stability and pressure drop coeffi 纵观全文，本文成功地将cfd技术和实验流体力学方法应用于新型双钝体涡街流量计的研究，并对旋进旋涡流量计的流体振动特性和抗干扰方法进行系统研究，提出了旋进旋涡流量计抗干扰设计的新方法。
