横截面

Firstly,after the image preprocessing,some features such as axis degree,circularity and central moment are extracted,then BP net is used as weak study machine,and integrate historical information into successive boosting learning.

预处理棉纤维的横截面图，把体现棉纤维的特征的指标从纤维横截面图像中提取出来；然后利用训练好的BP网络作为弱学习算法，使用每一个Boosting分类器学习的历史信息，基于线性回归特征消除策略，消除冗余，据此判别一幅纤维截面图像是否为棉纤维截面图像。

It was found that fibers of circular cross section produce greater cohesion in webs and slivers than do trilobal fibers.

圆形横截面纤维在棉网和棉条中，比三叶形横截面纤维能产生较大的粘着作用。

It is shown that the mechanical properties including Young's modulus, tensile strength, critical strain and stress under buckling can be enhanced with the decreasing of intershell spacing. The shear strength can be enhanced by 2-3 orders of magnitude when the intershell spacing is reduced to 20%, which is also dependent on commensuration. Zigzag-type carbon nanotubes have higher shear strength. The axial stress in tubes when the load transferring from outmost tube to inner tube is observed as well.

研究了单壁纳米管束横截面的六方化失稳现象，给出各种管径的面内压力－应变关系曲线；每条曲线都给出一个明显的拐点而且有很强的非线性；线弹性模量与参考构形有关，也受管直径的影响；分析了管束横截面的晶格不稳定性特征，表明晶格的缺陷能够明显的减小临界值；模拟了在不同应变下纳米管束对静水压的反应，发现不同压力下的截面形态不同，在很高压力下相邻管之间会形成化学键。

For the purpose of this requirement, a wire crossing the imaginary plane more than once is treated as separate wires and the cross-sectional area of a wire having a non-circular cross-section shall be taken as the cross-sectional area of a circular wire having a diameter equal to the maximum width of the wire having the non-circular cross-section.

为了达 到这一要求，电线不仅一次通过这个假想面。计算横截面积时，散线或非圆截面的电线的横截面积等同于圆线的最大直径横截面积。

Meanwhile, the influence of the main parameters on longitudinal metallography of fiber is analyzed.

文中深入地分析了金属长纤维横截面的形成机理，给出了上述各主要工艺参数对纤维横截面卷曲程度和纤维横截面金相组织的影响趋势，同时还分析了各主要工艺参数对纤维纵向金相组织的影响情况。

If the instrument is subjected to torsional loads, the shear stress at every cross section is proportional to the torque and the radical distance from the bars axis, and is inverse proportional to the polar moment of inertia of the cross section.

扭转载荷下，横截面某点的切应力与扭距成正比，与到截面中心的距离也成正比，与横截面的极惯性距成反比。

The morphologic change of muscle fibers: At the early stage of denervation, the area of cross sections decreased, some muscle fibers turned into angular fibers, nuclei congregated around the center of the fibers. After 8 weeks of denervation, atrophic and hypertrophic fibers coexist. Collagen increases under the endomysium and between the fibers.

肌纤维的组织形态学变化：面部肌肉失神经支配早期，肌纤维的横截面面积变小，出现角状纤维，肌细胞核聚集，细胞核从肌纤维边缘移至肌纤维中央附近；失神经支配后期，肿胀与萎缩的肌纤维并存，肿胀的肌纤维的横截面成倍大于正常的肌纤维，而萎缩的肌纤维的横截面则成倍小于正常的肌纤维；有大量的角纤维存在，肌纤维之间有较多的结缔组织增生。

Results The crosssectional area and the number of nerve fiber were (2.46 ± 1.03) mm2 and 1 305 ± 239 for the profundus nervi ulnaris,(2.62 ± 1.75) mm2 and 1 634 ± 343 for the recurrent branch of median nerve,(1.60 ± 1.39) mm2 and 1 201 ± 235 for the superficial branch of ulnar nerve, and (2.19 ± 0.89) mm2 and 1 362 ± 162 for the comman digital nerve of the ring finger.

结果 尺神经深支横截面积为（2.46 ±1.03） mm2，纤维计数（1 305 ± 239）根；正中神经返支横截面积（2.62 ± 1.75）mm2，纤维计数（1 634 ± 343）根；尺神经浅支横截面积为（1.60 ± 1.39）mm2，纤维计数（1 201 ± 235）根；正中神经中环指指总神经横截面积为（2.19 ± 0.89）mm2，纤维计数（1 362 ± 162）根。

In the direction of flow between the first cross section (50) of flow and the second cross section (52) of flow, a third cross section (54) of flow is formed between the valve member (40) and the valve housing (36), said third cross section (54) of flow being larger than the first cross section (50) of flow and the second cross section (52) of flow.

在流动方向上在第一通流横截面(50)与第二通流横截面(52)之间在阀元件(40)与阀壳体(36)之间形成第三通流横截面(54)，该第三通流横截面大于第一通流横截面(50)和第二通流横截面(52)。

The cross section stress problem of variable section round bar in axial tension and compress was studied.

通过分析变截面圆杆轴向拉压时横截面上的应力问题，论证了在该类图杆横截面上存在沿径向的剪应力，导出了计算该剪应力的公式。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。