The size of the nanoparticles prepared with the flow - levitation method can be controlled by controling the gas pressure in the action tube , the velocity of cooling gas flow and the temperature in the melt metal globule 自悬浮定向流方法制备纳米铝粉和铜粉的过程中，通过控制反应管内的气体压力、冷却气体的流速、熔球的温度等因素可以对粉体的尺寸分布进行控制。
Particles in the star move around rapidly due to high temperature creating a high gas pressure . together with the radiation pressure generated by the photons , they exert pressure pushing outward to balance gravity s inward pull . then , a star becomes stable and now enters the main sequence phase 恒星内部所产生的高温，会令粒子急剧运动，产生向外的气体压力，再加上光子的辐射压力抵消掉向内的引力，令恒星保持稳定，进入主序星阶段。
The gas feed automation system , which includes field instruments , gas feed controller , wireless remote supervising system , and so on , will realize following functions : gas flow measurement , gas pressure and temperature measurement , gas flow control , gas pressure regulation , intermittent gas lift , wireless remote monitoring , and etc . this paper will discuss the following content in detail : first part is introduction 该自控系统包括现场变送仪表、气举配气控制器和无线远程监控等，主要完成天然气流量计量、气体压力温度检测、天然气流量控制、管道干压调节、间歇气举以及远程监控等功能。本文将会重点介绍以下内容：首先是概述部分，简要介绍了气举采油技术和气举配气系统的地位和现存问题，并介绍了配气自控系统的主要性能和优点。
Oddly , the inferred elapsed time between ejection episodes , about 500 years , is too long to be explained by dynamic pulsations ( in which the star contracts and expands , in a gentle tussle between gravity and gas pressure ) and too short to represent thermal pulsations ( in which the star is driven out of equilibrium ) 奇怪的是，不连续喷发的间隔据推估大约是500年，但这段时间实在太长而不能以动力搏动（恒星因重力与气体压力间温和的交互作用，而产生收缩与扩张的现象）来解释，不过却又短到无法用热力搏动（恒星被驱向非平衡状态）来描述。
( 3 ) the most principal factors that influence the supersonic atomization process include the flow ratio of the gas - liquid metal ( gmr ) value , the flow of atomizing of gas and the range of the inverse vortex taper . the more of the value of three factors , the more advantage they are for the atomization and the more fine the powders are . ( 4 ) the produced powders are the best in efficient atomization efficiency , particle diameter , particle shape and dispersion when the solder alloy is zhl63a , atomizing medium is n2 , the protrusion h = 6 . 0mm , atomizing gas pressure p = 100mpa , over - heat temperature t = 167 ( t = 350 ) 研究结果表明： ( 1 )超音速雾化器的气体流场在导液管下端形成一个倒涡流锥，在二维空间上呈轴对称的双峰分布，负压形成于这个倒涡流锥内； ( 2 )修正后的雾化气体速度公式可以满足超音速雾化的要求； ( 3 )影响超音速雾化工艺最根本的因素有气液质量流率比( gmr )的大小、雾化气体流量和倒涡流锥范围，三个因素的值越大，对形成细粉越有利； ( 4 )在焊锡合金为zhl63a ，雾化介质微n _ 2 ，导液管突出高度取h = 6 . 0mm ，雾化气体压力取p = 1 . 0mpa ，合金过热度取t = 167 ( t = 350 )时，所制得的粉末在有效雾化率、颗粒球形度、粒度及其离散度三个方面综合性能最好。
The conclusions are drawn as following : 1 . regularity of fabrication in aluminum matrix composite ring - shaped performs with large dimensions and effects of parameters were investigated , based on the novel crucible movable spray deposition technology and equipment . the optimal parameters are that the diameter of the delivery tube is 3 . 8mm , spray gas pressure is 0 . 8mpa , spray height is 200mm , and transferring pressure of sic is 0 . 5mpa 通过系统的实验研究得到如下结论: 1 .基于新型的移动坩埚自动化控制喷射沉积环坯制备技术及装置,研究了大尺寸铝基复合材料环坯的制备规律,讨论了喷射沉积工艺参数对沉积坯形成过程的影响,得到了最佳工艺参数:导流管直径d = 3 . 8mm ,雾化气体压力p = 0 . 8mpa ,喷射高度h = 200mm , sic颗粒输送压力p送= 0 . 5mpa 。
Firstly , this paper introduces some basic theories on computer simulation of airbag - unfolding , and presents two key technologies : finite element model and contact impact model of the airbag system . through analysis of protection of airbag for occupants , this paper takes three parameters into consideration in the simulation . on the basis of that , this paper presents an experimental method to validate the computer simulation 通过分析气囊对人体的保护作用，提出了评价气囊工作性能的三个参数：碰撞加速度、速度和气囊气体压力，并以此作为试验装置设计的依据，为后面的试验研究提供了理论基础，确立了试验装置设计方案以及设计的主要技术参数。
In this paper , basic pneumatic - measuring theory and air circuit system working principle are introduced . the pneumatic - electric transducer employs a mpx5500dp silicon pressure sensor which converts air pressure signal into voltage signal , and displays on the electron column after the signal conditional circuit ’ s processing 本课题从分析气动测量的基础理论入手,研究气路系统的工作原理,用mpx5500dp扩散硅压力传感器将气体压力信号转换为电压信号,进而研制成功一种气电转换器。
In recent years , it is obtained from experiments that water infiltration is affected by air pressure , the problem on one - dimensional water infiltration is soloed by many researchers . in this paper two - dimensional water infiltration with air - out is considered and numerical simulation is made . unsaturated infiltration is the process of factors coupling each other 近年来，许多研究人员从实验中得出了气体压力变化对水流入渗有影响，并对一维水流入渗问题进行了求解，本文将进行考虑气体排出过程影响的二维水流入渗问题的数值求解。
Aimed at some problems such as short spraying distance , electricity - leaking and reverse ionization among electrostatic nozzles existing in the country , a induction charging and pneumatic energy electrostatic nozzle was designed . the basic designing theories , structure and working process of this nozzles were theoretically specified in the paper . and then the atomization quality and charge performances of this nozzle and its affecting factors were studied by carrying out performance experiment and statistic analysis . result of the studies indicate : ( 1 ) some progress were made in solving the problems list above ; ( 2 ) from this nozzle , droplet were minute and uniform , and higher charge - mass ratio can be obtained under lower electrostatic voltage , thus the atomization quality and charge performance of this nozzle were both better ; ( 3 ) within the experiment extend , air pressure at 0 . 2mpa , electrostatic voltage at 2400v were the most suitable parameters for the nozzle ; ( 4 ) the regression equations for describing droplet size , intensity of spray current and charge - mass ratio of this nozzle obtained from the experiment data had higher forecast precision ; ( 5 ) cross - effect of all factors were not significant , the atomization quality and charge performance were relative dependency affected by the factors 诸试验因素中，充电电压和喷孔直径对雾滴荷质比均有极显著的影响；气体压力和液体流量对雾滴荷质比的影响均不显著；影响雾滴荷质比的主要因素依次为充电电压和喷孔直径; ( 8 )在300v 、 600v 、 1200y 、 1800y 、 2400v 、 3000v六种充电电压t ，雾滴荷质比先随充电电压的增加而增大， 2400v后荷质比减小，推测:对于所研制的喷头可能存在一个最佳充电电压; ( 9 )由充电电压和喷孔直径的不同搭配所得雾滴荷质比不同这一结果，可看出，较大充电电压需配备较大喷孔直径以增强雾滴荷电效果; ( 10 ) td3 . 6和td3 . 4两喷头的雾滴荷质比曲线趋于重合，说明喷孔直径大于沪3
