查询词典 backflow

The interior flow of pump is the quite complicated turbulent flow. It is affected not only by the circumrotation and the surface curvature of impeller, but also by the sandy materials, even has the backflow and disengaged flow. They are one of the rather complicated numerical calculations in the fluid engineering field.

离心泵的内部流动是很复杂的湍流流动，同时由于受旋转、叶片表面曲率和泥沙颗粒的影响，还拌有脱流、回流等流动现象，是流体工程中较难的试验研究和数值计算问题之一。

Chapter 4 includes an overall analysis of the scale and regional distribution of the backflow and it is found that although the scale has been expanding, yet it is distributed disproportionably among different regions, specifically the East China occupying a comparatively larger percentage while the middle and west areas only a small proportion, and the unbalanced distribution has not changed much even after the reform in the tuition system and the implementation of Enrollment Expansion Policy.

分析结果表明，我国高等教育人才对农村的回流规模是不断扩大的，但是高等教育人才回流在地区之间的分布是不均衡的。东部地区占有了相对较多的回流人才，中西部地区较少。高等教育收费改革和扩招以后，人才对农村的回流率不断提高，回流规模继续扩大，但回流人才在地区之间的分布特征基本没有改变。

There should be a validated method of backflow prevention in the line supplying the filling area for nonmedicinal gases to prevent contamination of the medicinal gas.

为预防对医用气体的污染，非医用气体的灌装线必须有经过验证的阻止回流的方法。

There should be a validated method of backflow prevention in the line supplying the filling area for nonmedicinal gases to prevent contamination of the medicinal gas.

医用气体的污染，非医用气体的灌装线必须有经过验证的阻止回流的方法。

Backflow prevention assemblies MUST be installed by a licensed journeyman tradesperson, who is recognized by the authority having jurisdiction, and inspected for compliance with local safety codes.

防回流阀总成必须由有资格证书的熟练技术人员安装，安装人员必须通过有关主管部门的认可，并符合当地安全规程的要求。

Series 912HP High Pressure Hose Drop Backflow Preventers are specifically made for isolation protection on high pressure plumbing supply lines, such as high pressure hose drops which are used for the washdown of equipment and facilities.

系列912HP高压低垂软管防回流阀专用于对高压供应管道提供隔离保护，如用于设备和设施冲洗的高压低垂软管。

However, from the view of the structure and shape of the Orbal oxidation ditch, the round or ellipse tri-ditch type may be difficult to plane layout for the engineering with narrow land locations; the independent sedimentation tank occupies relatively large area of land; central island counts some areas which enlarges inefficient land demand; and the backflow of sludge and nitrified water from the sedimentation tank relies on dynamic system, which increase the cost of construction and operation.

但就奥贝尔氧化沟的工艺构型来看，三沟道的圆形或椭圆形沟型对于狭长的工程选址地来说，平面布置相对困难；而且奥贝尔氧化沟需要独立的二沉池，占地较大；中心岛消耗一定的面积，增加了无效占地；另外，二沉池的污泥回流依靠动力回流，增加了基建和运行费用。

Regarding to model 1, firstly analyzes and studies principle as well as formation of detonation wave, the internal flow field structure of the detonation chamber. Then study the flow field structure near the outdoor of the detonation chamber, backflow process of the dilatation wave after detonation wave reach the outdoor and the change of thrust wall pressure and so on.

对于模型1，首先分析研究爆震波在爆震室内形成传播机理和爆震室的内流场结构，然后研究爆震波传出爆震管以后爆震管出口处的流场结构，膨胀波的回传过程以及推力壁压力随时间的变化等。

When a sudden power failure or accident or normal pump stops when the pump stops, the valve inlet water velocity to reduce stress Agency, the valve plate also fall, when its velocity is zero (that is, inlet flow rate is zero Department), large valve plate because of its own gravity and rapidly turn off (time 3s ~ 5s), the majority of water to prevent backflow, when the valve before and after the formation of a water pressure, water stress, on the one hand through the small valve at the bottom of the three slot for pressure relief vent pressure. 4 water stress from the bypass tube into the cavity patch up the control room (this process for the suction pressure chamber that can effectively absorb the energy of water), when water stress on cavity than inferior vena cava, the pressure of water promote the diaphragm down mobile , the current cavity pressure of water being squeezed out all the small valve plate slowly drop back to standby status, the process time to ease closure adjustable (3s ~ 150s), then the valve has been fully closed, watertight.

当突然停电或事故停泵或正常停泵时，阀门进水口处压力水流速降低，大阀板也随之下降，当其流速为零时，大阀板由于自身重力而迅速关闭（时间3s～5s），可防止大部分水倒流，此时阀门前后形成一种水压差，压力水一方面通过小阀板底部的三条泄压槽进行泄压。4）压力水从旁通管进入膜片控制室上腔（此过程为吸压腔，能有效吸收一部分水能量），当上腔压力水大于下腔时，压力水推动膜片往下移动，当下腔压力水全部被挤出来时，小阀板缓缓下降，恢复到待机状态，此过程中缓闭时间可调节（3s～150s），届时阀板已全部关闭，滴水不漏。

It is indicated that the easily cavitated locations are at the top of orifice, the comer at downstream of orifice and the center of the backflow.

结果显示，容易发生空化的部位主要有三处：一是孔板顶缘处，二是孔板下游角隅处，三是孔板下游回流旋涡中心部位。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。