A reasonable position of driving nozzle helps to achieve the maximum material flow that also depends on other parameters such as backpressure , properties of conveyed material and driving gas . it is observed that , an increase of convergent section angle is harmful to the pneumatic conveying system , and also influences on the mass flow rate of conveyed material , the distribution of static pressures in injector and the pressure drops of conveying pipe . in addition , within a reasonable scope of air mass rate , increasing the driving jet velocity is more advantageous than enlarging the dimension of driving nozzle 试验研究发现，气体喷嘴位置对气固喷射器的输送能力影响最大，气体喷嘴存在某一最佳位置，而这一最佳位置与背压、输送物料特性和输送风特性相关联；气固喷射器的收缩角对其输送能力、内部静压分布和输送管阻力特性均有适量影响，收缩角增大对整个输送系统均不利；在适当的输送风范围内，提高气体喷嘴出口速度比扩大气体喷嘴尺寸更为有利，但气体喷嘴出口速度过高会增加气固喷射器和输送管内的能量损耗，给输送带来不利的影响；系统背压与气固喷射器的气体喷嘴出口速度的选取有关。
Abstract : optimum distances between primary nozzle exit and mixing tube inlet , static pressure recovery of the mixing flow in mixing tube 、 total pressure distributions at the exit of mixing tube 、 pumping coefficients and total pressure losses of the exhaust ejector systems with four different types of primary nozzles have been measured in the experiments 文摘:对4种主喷管组成的排气引射系统的引射系数和总压损失、各主喷管出口与混合管进口之间的最佳间距、混合气流在混合管内的静压恢复及混合气流在混合管出口处的总压分布等进行了测量和对比。
New developments in decision theory , artificial theory and dynamic analysis method are applied to evaluation the possible projects . the main contents in this paper are included as follows : first , has improved an format reasoning method based on multiple attribute utility model and knowledgebase theory ; second , has proposed complex utility model by improving the theory of multiple attribute utility ; third , has presented a kind of weapon intelligent decision support system , based on the complex utility model and developed with com / dcom criterion ; forth , this paper also has build the dynamic simulation model for long - rang multiple tube rocket launcher system , and the tire dynamic model has applied in the rocket launcher system dynamic simulation model ; fifth , through building the rocket - launcher contact model , this paper has analyzed the dynamic forces between the rocket and launcher ; finally , this paper has build the evaluation model of the project about improving existing rocket launcher to the launcher that using canister , and get the conclusion through using the widss . the studies in this paper not only proposed scientific warrant to the choice of projects in this pre - studied national defense task about improving existing rocket launcher to the launcher that using canister , but also can give other studied tasks with decision supported 主要内容包括：在总结决策分析与专家系统规则库技术的基础上，提出了融决策分析与专家系统规则库技术于一体的形式化推理机制，该机制能有效的将定量计算和定性知识融为一体，将规范的决策分析解题过程与专家系统特有的演化推理方法有机结合起来；在多属性效用理论的基础上，建立了一般形式的复式效用模型，并实用化了全相关乘式效用模型，提供了较完善的通用建模、分析和解释功能：引入了com dcom组件技术，开发了基于组件的widss系统，该系统基于形式化推理机制，易于扩展，能够面向多种决策问题，具有较强的通用性；建立了远程多管火箭炮全炮动力学仿真模型，将充气轮胎动力学模型、轮胎和路面的相互作用模型运用于多管火箭炮动力学仿真计算中；利用碰撞接触理论，对火箭弹在定向器管内的运动受力情况进行了仿真计算；建立了远程多管火箭炮箱式发射改进方案模型，并利用动力学仿真计算结果在widss系统中进行了方案性能评估。
In the laminar flow regime , a analytical mathematical model is obtained by analyzing the film flowing in the wavy wall tube . in the turbulent flow regime , mathematical model almost ca n ' t be obtained directly because the turbulent flow in wavy wall tube is very complex , the model is obtained by quoting some results which are theorized by other studiers . in the part of experimental study , the flow form in the wavy wall tube is observed by transparent quartz glass wavy wall tube apparatus , the evaporation experiments are carried out in a 3 meters steel wavy wall tube , using glucose as the medium , heat transfer is invested , the heat transfer correlations of wavy wall tube evaporator are obtained 数学模型的建立过程中，对于液膜层流流动，直接对波形管内的降落液膜进行理论分析，得出液膜层流流动下数学模型的解析式；对于液膜湍流流动，由于湍流流动的复杂性，再加上所采用的波形管对湍流流动的影响，直接对降落液膜进行理论分析建立数学模型是极其复杂的，通过采用以前一些研究者得到的理论分析与实验结果，并引入与波形管的形状特征参数有关的修正系数k ，建立液膜在湍流流动下的数学模型。
The theory of the simulation is that , firstly put fuze and parts in simulation device in reverse , then fire them in high speed by air gun , and they fly into gun spinning quickly and impact cushion and brass block in it , negative acceleration because of impact is to simulate setback , meanwhile they spin with spin gun when impacting , so spin environment can be simulated , so the simulation system can stimulate setback and spin of fuze in fire 该模拟系统的原理是将引信及其零部件倒置在模拟弹丸中，通过空气炮以高速发射出去，然后飞入高速旋转的旋转管内，与旋转管内的缓冲块和黄铜块碰撞，碰撞而形成的负加速度作为引信发射时受到的后坐，由于碰撞时与旋转管一起旋转，模拟引信发射时的旋转环境，达到模拟引信发射后坐与旋转环境的目的。
The result shows that the heat transfer coefficient within the hollow fiber module with laminar flow can be calculated based on the correlation . by analyzing the equation , it was founded that the heat transfer coefficient under laminar flow is almost independent of the feed flow rate . numerical simulation of temperature distribution in hollow fiber membrane module with laminar flow was carried out 首先采用纯水为研究体系，研究分析了中空纤维管内的传热系数，研究表明，纤维管内的流动属于层流状态，其边界层传热系数可用关联式来计算，由此式看出，层流状态下，流速对传热系数的影响很小。
Methods of 14 normal male japanese white rabbits ( aged approximately 4 months ) , 7 ( randomly chosen ) were subjected to vasal ligation near the cauda epididymidis after exposure of the testis and vas deferens via a scrotal incision , and the other 7 subjected to vasectomy after exposure of the vas in the inguinal canal through a small ventral midline incision 方法正常雄性日本大耳白兔14只（约4月龄） ， 7只（随机选择）经阴囊切口暴露睾丸和输精管后靠近附睾尾进行输精管结扎，另7只从耻骨联合上方的腹正中线上作一小切口，暴露腹股沟管内的输精管后进行输精管结扎。
Spectral method and spectral element method are both used in the present dns . the flow is developed from an initial velocity field whose mean and root mean square values are fitted to the experimental data . the reynolds number of the flow is 2250 based on the mean velocity and the radius of the pipe 本文在空间离散上采用谱方法和谱元法的结合，通过在圆管层流速度剖面上叠加随机扰动作为初始场的方法，计算了管长为，平均雷诺数为2250的光滑圆管内的湍流流动，建立了圆管内较低雷诺数下速度场和压力场的数据库。
Adequate preoperative fluid hydration , intensive hemodynamic monitoring , ready - prepared blood and vasopressor drugs , inspiration of 100 percent oxygen , and copious irrigation of marrow debris after reaming are useful prophylactic methods to lower the catastrophic complication during cementation 足够的术前水分补给，手术中精细的生命徵象监视，随时准备好的血液及增压药物以备不时之需，呼吸纯氧以预防低血氧症，在骨髓腔管被扩钻后使用大量的水清洗骨髓腔管内的杂质，这些是降低骨水泥心脏血管衰竭并发症发生的有效方法。
Some statistical features of turbulent pipe flow including mean velocity profile , turbulence intensity , reynolds shear stress , skewness and flatness are studied based on the pipe flow data bank . comparing the results with experimental data and other dns results shows that our computation is correct and credible . in order to research the burst period in turbulent pipe flow , burst detection methods are studied in the present paper 为了得到圆管内的猝发周期，本文还对直接数值模拟的结果进行了猝发事件的检测，通过对ulevel 、 mulevel和vita等方法以及各种方法内门限值取值得比较，我们认为vita方法中门限值k取0 . 7 - 1 . 0所检测出的猝发周期较为接近真实值。
