螺旋

It shows that it is possible to increase the start oscillation length by tailoring magnetic field's amplitude and its period without changing the synchronous condition of the fundamental wave; in the meantime, when there are two or more azimuthally asymmetric space harmonics in the high power broad-band helix TWTtraveling wave tu...

与此同时，对起振长度、初始非同步速度参量随皮尔斯增益参量、空间电荷参量、损耗参量等的变化，以及在超宽带行波管中当存在两个或多个角向非对称空间谐波时，起振长度、初始非同步速度参量随周期永久聚焦磁场的变化进行了研究。优化设计聚焦磁场、电子注和螺旋线慢波系统的参量可以对螺旋线行波管的稳定性分析提供必要的依据。

Long stretches of the continuous DNA molecule wind around these clusters of proteins, or histones, forming beadlike complexes known

这些螺旋和超螺旋形成致密的染色体组结构。每个长链DNA与组蛋白和非组蛋白一起构成染色质物质。

Expression methods and growing rules accord with self-organization way are studied for binominal curves and surfaces such as arc, spiral, helicoid, ellipsoid and fractal curves such as snow-form curve.

研究了圆弧、螺旋线、螺旋面、椭球面等常规二次曲线/曲面以及雪花曲线等分形曲线的自组织表达和生长规则，实现并验证了其生长算法。

Centerless screw conveyors do not contain a central shaft, and instead consist of an empty helix.

Centerless螺旋输送器不包含一个中央轴和包括一个空的螺旋。

We discuss this method in detail and the role of it in the investigation of the optical property of the cholesteric liquid crystal.

研究了线性偏振光在螺旋液晶中的传播特性，并给出了光经过螺旋液晶后电场强度的矩阵表达式。

Methods 12 cases of pulmonary embolismsuspected by clinical diagnosis were done SCT Angiography or MSCT Angiography,The relvanted CT date were analyzed retrospectively,compared with else imaging date and clinal date.

对12例临床高度疑诊肺栓塞的患者行螺旋CT肺动脉造影或多层螺旋CT肺动脉造影检查，分析所获得的相关CT资料，并和其他影像、临床资料相对照。

And a screwy algorithm based on digital image from mono-view is presented. This algorithm needs the four-region sign with the screwy boundary labeled on the surface of columniform targets. Then the length of the intersecting lines of the object's axis and the screwy boundary are gained by means of digital image processing, such as gray histogram balancing, Susan edge detection and Hough transform. Finally, the object's rolling angle is accurately gotten in shooting range.

该方法通过在圆柱形目标表面涂上边界为螺旋线的四区域标志，综合运用直方图均衡化、Susan边缘检测以及Hough变换等数字图像处理技术，从光测图像中得到各个时刻目标中轴线与螺旋线的相交线段的长度，由此可高精度测出空间目标的滚转角，从而有效地解决了靶场试验中空间目标滚转角的测量难题。

When end surface is neglected, the reflective energy will return to the filament efficiently if the filament is at the centre axis of the columniform lamp shell. 3 Compared with the straight tungsten filament that has a smooth surface, the helical one obtains higher absorbance which can achieve 0.6~0.7 under the actual screw pitch measurement.

当灯的管径为10 mm，而灯丝外径为1.5 mm时，节能可达12%到13%。2）对圆柱形灯外壳，在不考虑端面影响时，光源的灯丝若处于外壳的中心轴上，则反射的能量会有效地返回灯丝。3）螺旋结构的灯丝比表面光滑的直钨丝有更高的吸收率，灯丝绕成螺旋后在现行的螺距尺寸下吸收率能达到

While the PNA is neither classical nucleotide nor classical protein, and can resist the discomposing of nuclease and proteinase.

肽核酸与双螺旋脱氧核糖核酸更易形成三螺旋的一个重要原因是肽核酸不带净电荷。

Abstract］ Objective To evaluate the value of spiral CT dynamic contrast-enhancement scanning on pulmonary embolism by analysing the CT appearance of pulmonary embolism restrospectively.Methods Collect and analyze the appearance in multi-slice spiral CT of 24 patients with pulmonary embolism,especially the embolismic index,the involved proportion of central pulmonary arteries,the presenting proportion of bronchodilation and pulmonary infarction.

目的 回顾性分析肺动脉栓塞的CT表现，探讨层螺旋CT动态增强扫描对肺动脉栓塞的诊断价值方法搜集经多层螺旋CT动态增强扫描确诊的肺动脉栓塞24例，回顾性分析其CT表现，重点分析肺动脉栓塞指、中央肺动脉受累比例、有无支气管扩张显示、是否合并肺梗死。

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。