单向作用

The main reason causing the defects and low angle boundaries in SC casting is the perturbations of heat flow and the slight misorientation at the S/L interface. An uniform and unidirectional heat flow is required to produce a single crystal casting free of low angle boundaries or splaying

单晶组织中由于晶体取向与热扩散场综合作用因素造成的亚单元生长形态的改变是造成单晶缺陷的主要原因，控制均匀、严格单向性的热场，并利用单晶生长的各向异性特性，可以避免发散型枝晶组织和小角度晶界的出现。

On the basis of three-step finite element method, the flow past circular cylinder with splitter plate is analyzed by using large eddy simulation turbulent model in single direction flow.

在三步有限元数值方法的基础上，利用大涡模拟湍流模型对单向流作用下带横隔板圆柱绕流进行了数值分析。

Evidence suggests that 1 under more stable stratification, the basic flow, if moving faster at low and high levels (particularly in the presence of jets there), allows a resulting meso-β unsteady wave to propagate eastward with respect to basic flow and even at greater velocity compared with it; 2 vertical windspeed shear of basic flow causes instabilities of the TWT perturbation; 3 considering the second derivative of basic-flow wind with respect to z (denoted by zz≠ 0 which is simply given as β* hereafter) the expression for the phase velocity of vortex Rossby wave is obtained, which is unidirectional in propagation with respect to basic flow; 4 VRoW has its physical origin from β*, i.e., from z-varying heterogeneities of y-direction averaged vorticity of the basic flow field; 5 VRoW phase velocity is associated with zonal wave number k, its energy is dispersive and the group velocity exists in the x direction; 6 when windspeed meets the condition of β*, TWT disturbance instability may be that of mixed VRoW and gravity wave; 7 if basic flow is subject to linear shear but does not meet the condition of β*, the TWT instability is that of inertia-gravity wave.

在大气层结比较稳定的情况下，如果基本气流在低层和高层较大(有可能存在低空急流和高空急流)，此时产生的β中尺度不稳定扰动相对于基流向东传播，甚至于快速向东传播。基本气流在垂直方向上的风速切变对于中尺度横波型的扰动起着不稳定的作用。如果考虑基流的二次切变，可以得到涡旋Rossby波的相速度表达式，涡旋Rossby波相对于基本气流是单向传播的。涡旋Rossby波产生的物理根源是基本流场的风速二次切变，亦即基本流场y方向的平均涡度在空间z方向上的不均匀所致。涡旋Rossby波的相速度与纬向波数也有关，它的能量是频散的，其在纬向x方向也存在群速度。在基本流场的风速存在二次切变时，横波型不稳定可能是混合的涡旋Rossby重力波的不稳定；而在基本流场的风速仅仅存在线性切变，不存在二次切变时，横波型扰动的不稳定则是重力惯性波的不稳定。

The pilot unloading valve 5 of the one-way valve can be achieved system-pressure pump and unloading.

由于先导卸荷阀5内的单向阀作用，可以实现系统保压而油泵卸荷。

It was demonstrated that the dependence or independence of recA gene is not related to the direction of replication of the plasmids or phages in the free state.

实验结果说明，依赖与否和它们在游离状态中复制方向无关，从而否定了recA基因的作用是把质粒或噬菌体的游离状态的单向复制发动机构改变为整合状态的双向复制发动机构这一假设。

A new-type bike features that its pedal crank has an arc rack bar acting on the ratchet gear in single direction and in turn driving the drive chain wheel, a reset unit composed of crank mechanism is used to make left and right pedal cranks be pedaled alternatively, and its front movable saddle plate is connected via connecting rod to pedal crank for making rider comfortable. Its advantages are high drive performance and efficiency and saving labour.

一种新式自行车，其最大特点是蹬踏杆上含有一弧形齿条，由该弧形齿条上的轮齿作用于具有单向离合的棘齿轮，从而带动主动链轮转动，由曲柄机构组成的复位器使左右蹬踏杆能够交替连续踩踏以驱动自行车行驶，前活动座板与蹬踏杆由连杆相连结，从而实现同步摆动给以乘骑者踩踏感到舒适，该发明具有传动性能好，效率高，力损耗小等优点。

Based on the detailed analysis of existing dimension recognition methods, this paper concluded a common limitation of existing methods-"single-entry recognition", which has three distinct drawbacks. First, the only recognition entry reduces the capability to handle drawings of different qualities; second, the fixed search order for dimension elements block algorithm seeking all possible ways to find a dimension structure; third, single directional recognition of graphic elements uses no drawing context and thus can not make use of engineering knowledge.

本文分析了现有的尺寸识别方法，指出它们共有的局限性——单入口的识别过程：单一的识别入口限制了算法对不同质量图纸的适应能力；固定的元素搜索顺序阻碍了算法利用一切可能的途径寻找和识别尺寸标识结构；单向的独立于上下文的图形元素识别忽略了应用领域知识对识别过程的启发作用。

Also, because oil-absorbing tube 6 in the role of one-way valve 7, compressed air will not flow backward into the oil pipe from the oil-absorbing cup, so we can keep gas in a state of the oil gagged refueling, refueling is completed, screw plug oiling .

又由于吸油管6中单向阀7的作用，压缩空气也不会从吸油管倒灌到油杯中，所以就可以在不停气的状态下向油塞口加油，加油完毕，拧上油塞。

They serve a definite purpose in the overall traffic pattern.

这种单向式的车流，对整体的交通运作当然有一定的作用。

The stress redistributions induced by the fracture of some fibers and matrix elements for unidirectionally fiber-reinforced composites subjected to axial tension at cryogenic temperature were studied.

研究了在低温情形下受纵向拉伸荷载作用的单向纤维增强复合材料由部分纤维及基体断裂所导致的应力重新分布。

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。