螺旋管

The raw data was processed by using axial, coronal and double oblique multi-planar reformation; Images obtained were graded in terms of quality with a 5-point scale(5=excellent, 4=good, 3=fair, 2=poor, and 1=nondiagnostic). In grading image quality at axial MPR, The radiologic specialists focused on the subarcuate fossa, tendon of tensor tympani, facial recess, vestibular aqueduct and pyramidal eminence, In grading image quality at coronal MPR, attention was given to the scute, crista transversa, fenestra cochleae, lateral malleal ligament and snake eyes signature of cranial nerve, In the grading of the image quality at double oblique MPR, the radiologic specialists concentrated on the malleus, incus, stirrup bone, upper bony semicircular and aquaeductus fallopii, and then to implement statistical analysis. In order to choose the minimum tube current values and the maximum pitch that can satisfy the diagnosis request, image quality of axial, coronal and double oblique reformation images was compared with different tube current groups. 15 ears of volunteers were used to test the validity with the scanning parameter. Subsequently noise, MTF and dose length product were measured by phantoms in different tube current and pitch, the parameters obtained were compared and taken into statistics analysis.

扫描模式使用临床常用的颞骨螺旋扫描方式：管电压120 kV，准直宽度20×0.6 mm，视野200 mm，重建矩阵512×512，旋转时间1 s/r，重建层厚0.6 mm，重建间隔0.3 mm，分别改变管电流(380、300、200、160、120和80 mA)和螺距(0.8、1.0和1.2)进行扫描和重建，然后对颞骨进行横断面、冠状面和双斜面多平面重组，于重组后的横断层面图像上选取弓形下窝、鼓膜张肌腱、面神经隐窝、前庭导水管和锥隆起5个解剖结构，冠状面重组图像上选取盾板、横嵴、蜗窗、面神经的蛇眼征和锤骨外侧韧带5个解剖结构，双斜面重组图像上选取锤骨、砧骨、镫骨、上骨半规管和面神经管5个解剖结构，在双盲的情况下由放射学专家分别对各管电流和螺距下扫描的重组图像进行评分，随后进行统计学处理，从中筛选出满足诊断要求的最低管电流值和最大的螺距，分别采用患者25例(15耳)用该管电流值和螺距验证其可行性；然后利用模体分别测试各管电流和螺距下的图像的空间分辨率、噪声及其剂量长度积，并对测试所得参数数值进行比较和统计学处理。

The formula was established about calculating design parameters and technological parameters of ideal strip and bent strip in the period of forming. The thesis presented how to calculate the deformed area length and contact are radius of contact deforming between two elastic bodies on condition of the friction. The calculating formula of pinch force about plate-strip pinch mill was given and the results were analyzed that friction coefficient and radius of pinch rolls are very important for determining pinch force. Moreover, the rule of deforming and stress distribution of different 〓 ratio were gained on condition that the deforming was considered to be non-uniform distribution in the gap. The differential equations were got that calculate the displacements of large deflection of elastic cantilever rectangle plate with fixed end and the formula of the Finite Strip Method was conducted to study the regularity of mid-plane displacements, deformation and stresses for elastic-plastic large deflection bend of cantilever parallelogram plate with fixed or slidable end by integrating Prandtl-Reuss equation.

建立了一套完整的设计参数计算公式和在成型过程中理想带钢或具有月牙弯带钢的工艺参数的调整公式；在考虑摩擦力的条件下，对两弹性体接触变形过程中的接触变形区长度和接触弧半径用位移解法进行了研究，推导了板带递送机的递送力计算公式，从而得知在递送机设计过程中，应选择适当摩擦系数和辊身直径；另外，还从辊缝内带钢实际变形出发，分析了对于不同的〓值，带钢的变形规律及应力分布状况；建立了固定端悬臂矩形板弹性大挠度弯曲变形的控制方程，并且在对Prandtl-Reuss方程的积分处理的基础上，导出了固定端和滑动端悬臂平行四边形薄板的弹塑性大挠度的中面伸展位移、变形和应力的有限条元法公式，编写了Fortran语言计算程序，在各种参数条件下，对螺旋焊管成型过程变形规律进行了全面的分析研究，从而为螺旋焊管的生产和进一步的改进提供了理论依据。

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。

Regular coiled carbon tubes are prepared by pyrolytic decomposition of acetylene on titanium plates at 750℃.

规则螺旋碳管的形成与钛片的预处理有关，在盐酸处理过的钛片表面上所生长的碳管几乎都是规则螺旋形状的。

The old technology and equipment in the curve of columnar ,plane and cambered coiled pipes for circular pipe-coiled pipes and half pipe-coiled pipes were very complicated.

原有的圆管盘管和半管盘管中的柱面螺旋盘管、平面盘管和曲面盘管的结构繁杂、弯制质量差以及弯制工艺工装造价昂贵。

Series of products: 1, fully automatic production line of Duct flange molding machine, shears, press brake duct and other metal processing equipment. 2, using the entire computer-controlled production lines, specialized in the production mechanism Express rectangle duct flange, Germany duct flange, mechanisms spiral round, flat circular duct, all kinds of bend, the wind pipe fittings. 3, damper, exhaust valves, valve series; 4, muffler, static pressure box, muffler Venetian series; 5, aluminum, teak tuyere, such as stainless steel tuyere tuyere series; 6, Air Shower, Air Shower Channel, clean bench, and efficient delivery of clean air and other series; 7, vertical, horizontal air handling units series; 8, multi-functional modular air handling units series; 9, fan coil series; 10, ventilation, exhaust cabinet series, Fire cabinet centrifugal fan series.

系列产品：1、全自动风管生产线、法兰成型机、剪板机、折弯机等金属风管加工设备。2、采用全电脑控制的生产线，专业生产快速机制法兰矩型风管、德国法兰风管、机制螺旋圆形、扁圆形风管、各类弯头、风管配件。3、防火阀、排烟阀、阀门系列；4、消声器、静压箱、消声百叶系列；5、铝合金、柚木风口、不锈钢风口等风口系列；6、风淋室、风淋通道、洁净工作台、高效送风口等洁净系列；7、立式、卧式空气处理机组系列；8、多功能组合式空气处理机组系列；9、风机盘管系列；10、通风、排气柜系列、消防柜式离心风机系列。

The experimental results indicate that, over a ranger of tube side Reynolds number and Prandtl number (Re=4000~20000, Pr=6~7.5), the internal Nusselt number and friction factor of spiral-flat tube increased by 30%-150% and 20%-50% respectively compared with smooth tube at the same Re and Pr. The value of friction factor decreases with increasing the value of B/A as well as increasing that of S/de, and the same phenomena can also be observed for Nusselt number.

实验结果表明：管内Nu和f值均随均随B/A值和S/de值的增大而减小，但随B/A值的增加而减小得更快，B/A值对螺旋扁管管内传热与流阻性能影响更大；在相同Re和Pr下，螺旋扁管管内Nu数为光滑管的1.3～2.5倍；阻力系数f是光滑管的1.2～1.5倍。

On the basis of structural features and heat transfer characteristics of a spiral-grooved tube heat exchanger,a three-dimensional geometric model was established for the flow and heat transfer in a heat exchanger with water serving as its working medium.

根据螺旋槽管换热器结构特点及传热特性，建立了以水为工质的换热器流动与传热的三维几何模型。运用有限元分析软件ANSYS模拟出换热器在换热过程中速度场与温度场的状况，分别得到了螺旋槽管内壁与外壁的对流换热系数。

Spiral volume tube, compound pot complete equipment: in 1994, Shuangfei company designed the spiral pipe coiling machine, the slitting, curved side machine , the printer and cover machine for the a lot of customer.

螺旋卷管、复合罐成套设备：双飞公司在1994年为还为众多客户设计制造了螺旋卷管机、分切机、印刷机、弯边机、封盖机等复合罐成套设备。

Another important phenomenon we found is the self-repairing of broken C-C bond on the sidewall of SWNT by annealing at room temperature for several picoseconds.

当直径小于20〓时，体密度与纳米管的螺旋度有关。随着纳米管直径的增大，螺旋度的影响逐渐变小。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。