长度

QUESTION: After working for years in half-hour formats, how did you go about preparing three-minute episodes?

问：在创作了多年的半小时长度短片后，你如何着手准备三分钟长度节目？

Development and test of tubing length intelligent measurer.Wu Wenxiu,Liu Li,Li Wenxing,et alMechanical Engineering Dept.of Jianghan Petroleum University,Jingzhou City,Hubei Province

针对油管长度人工计量方法存在的计量精度差、工人劳动强度大、生产效率低等问题，研制了以单片微机为核心的油管长度智

The main research tasks and results are as follows:(1) Through comparing the stress intensity factor of compact tension specimen calculated by finite element software with the theoretical value, the feasibility of calculating fracture parameters of crack tip in ABAQUS software was verified.(2) The relationship between the elastic modulus of the material and research scale was studied based on deriving the cohesive stress theory and other relevant theories. And the elastic modulus of the material on meso-scale was determined.(3) Global model and sub-model of the finite element were built in th...e macro-scale, and stress-strain field nearby the crack tip was analyzed, and the results show that the detailed stress-strain in the crack tip could be obtained by using the sub-model technique.(4) In meso-scale, the crack growth model was also established by assuming the crack propagating along the grain boundary, and the detailed stress-strain field in the crack tip was obtained.(5) The effect of crack length on Von Mises stress, and maximum principal stress and strain was analyzed in meso-scale when equivalent KI equals 30MPa.m1/2. And the results show that except for crack tip area, the stress-strain distribution in whole specimen is not affected.

主要完成研究内容和取得成果如下：(1)利用有限元软件计算出紧凑拉伸试样的裂纹尖端应力强度因子KI值，其结果与理论值一致，从而验证了利用ABAQUS计算裂纹尖端相关断裂参量的可行性；(2)在研究内聚应力等相关理论的基础上，推导出了研究尺度与材料弹性模量的近似关系，并确定了介观尺度上的弹性模量；(3)在宏观尺度上建立了全局有限元计算模型和子模型，得到了裂纹尖端应力应变场分布，结果表明利用子模型技术获得比较准确的裂纹尖端应力应变场分布是可行的；(4)在介观尺度上利用平均晶粒尺度的方式建立了裂纹沿晶扩展模型，得到了裂纹尖端断裂过程区的微观应力应变场；(5)当应力强度因子为30MPa.m1/2时，分析了介观尺度上在裂纹沿晶扩展过程中裂纹长度对Mises应力、最大主应力和应变的影响，结果表明，裂纹扩展长度对试样整体应力应变分布影响不大，而对裂纹尖端区域有较大影响；(6)介。。。

The fiber optic distributed temperature sensor system can sense the change of temperature along the optical fiber by the form of continuous function of distance.

分布式光纤温度测量系统能在整条光纤的长度上，以距离的连续函数形式传感出被测温度随光纤长度方向的变化。

The actual production needs from oil field,aimed at tractor hoist that need replace pipe string and outside slippery jet pump that isn′t satisfied with discharge fracturing quickly in reality,a new type of jet pump inside sleeve type of jet pump is designed.

针对外滑套式射流泵在油田应用中不能满足压裂后快速排液的现况，研制出了一种新型的内滑套式射流泵，并提出了射流泵、喉嘴距、喉管长度、扩散管角度及长度的计算公式。

Normal or linear strain is defined as the change in length per unit length.

正改应变或线应变由每单位长度内的长度改变量来定义。

Aiming at calculation of the equivalent rigidity of truss stiffening girder in an aeroelastic model design of a long-span suspension bridge with truss stiffening girder,Aizhai bridge,a super-long -span suspension bridge across deep valley with single span,was taken as an example for investigation.

针对大跨度桁架加劲梁悬索桥气弹模型设计中主梁等效刚度计算问题，以矮寨大桥为实例，建立不同长度空间桁架加劲梁节段模型有限元模型，通过悬臂梁位移法反算得到主梁的等效刚度特性，研究了不同荷载施加方式以及不同梁段长度对等效刚度特性的影响。

Specify valve size, figure number and length to be added to existing stem length.

如果要增加阀杆长度，请指定阀门通径，型号和长度。

On the 27th day of the experiment, the researchers measured stem length, root-system length and the overall weight of the plants.

在第二十七天的实验中，研究者们测量了这些植物的干茎长度、根系长度以及整个植物的重量。

On the 27th day of the experiment, the researchers measured stem length, root-system length and the overall weight of the plants.

实验第27天，研究者测量了茎的长度，根系长度以及植物总重量。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。