共查询到18条相似文献，搜索用时 203 毫秒
1.
吴丽双 《泉州师范学院学报》2007,25(4):25-27,31
理论分析了小锥度POF的光传输特性,讨论了锥形POF的径向光强分布和传输效率,并实验验证了理论计算结果的正确性,说明小锥度POF可用于不同芯径光纤的过渡连接. 相似文献
2.
通过理论分析和仿真试验,研究了锥形光纤的几何形状对锥形光纤的传输损耗和耦合效率的影响。用几何光学的分析方法,说明了光信号在锥形光纤中的传输损耗远低于同类型的圆柱形光纤;仿真试验研究了光源与光纤的相对位置、锥形光纤的尖端半径、锥形光纤的锥角大小对锥形光纤耦合效率的影响。 相似文献
3.
理论分析了子午光线通过直锥形塑料光纤的光线传输原理,模拟计算了直锥形光纤的锥角α、光纤中心轴线夹角θ(m)与反射次数m三者的变化关系.通过重力垂直拉锥实验制作了大芯径直锥形塑料光纤,并得出相关的实验结论. 相似文献
4.
转动小拖板法是车床上加工圆锥面最常用的方法,其操作要点是：１粗车外圆（使外圆直径比锥体大径大１ｍｍ）。２松开小拖板转盘上的螺母,根据工件的圆锥斜角α（若没直接给出,应先求出）,将小拖板逆时针搬转α角（对正外锥体即大端靠主轴的锥体而言。若为倒外锥体... 相似文献
5.
设计了一套基于FPGA的快速求解双边滤波结果的系统。该系统由输入缓存器、计算模块和输出缓存器组成。利用图像采集端将图像采集输入计算模块;利用输入缓存器将图像进行重新分解,输出的数据符合模板计算模块的格式;接着对于输入缓存器输出的数据进行模板计算,得到输出数据;最后将输出的数据输入输出模块,将数据重新整合为图片的格式。该方法使得双边滤波在FPGA上得以实现,同时减少了双边滤波的计算时间,加大了双边滤波在机械的图像处理方面的实用性。 相似文献
6.
《西安文理学院学报》2016,(1)
圆锥齿轮减速器广泛应用在输入轴和输出轴需要相交成一定角度的机械设备中,传统的设计方法偏于保守.对具体的运输机用二级圆锥-圆柱齿轮减速器进行优化设计,以总中心距最小为目标函数,选择合理的设计变量,应用MATLAB工具箱获得目标函数的最优值.提出圆锥齿轮传动中名义中心距的概念,并通过背锥中心进行表达.与传统设计方法相比,优化设计使总中心距减小12%,二级圆锥-圆柱齿轮减速器的体积更小,结构更加紧凑. 相似文献
7.
利用飞秒激光微加工技术在单模光纤—多模光纤—无芯光纤"三明治"光纤结构的无芯光纤端加工菲涅尔透镜,从而形成了新型光纤光镊.对该光镊结构的出射光场以及不同条件下的光阱力变化进行了数值计算,通过实验验证了理论的可行性.这种光纤结构可用于粒子捕获、操控以及微流控分析等领域. 相似文献
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9.
张少先 《黑龙江大学工程学报》2022,(1):68-74
设计并验证了基于三芯光纤马赫-曾德尔干涉仪(Mach-Zehnder interferometer,MZI)的应力不敏感向量曲率传感器.该干涉仪的结构是在两个标准单模光纤之间熔融焊接一段三芯光纤形成的.由于三芯光纤的3个纤芯在同一平面上呈直线分布,因此在光纤弯曲时,会改变两个侧芯的参数.这种结构的干涉仪可以用于矢量曲率... 相似文献
10.
利用分布反馈式半导体激光器（DFBSL）注入八字形光纤环实现了带宽增加的光随机信号输出.在实验中,DFBSL工作在阈值附近,由于其自发辐射而产生的随机信号经放大后注入到八字形光纤环.实验结果表明：经八字形光纤环输出地随机信号带宽增加,并且当八字形环左环无光隔离器时输出信号的随机性要优于有隔离器时的情况. 相似文献
11.
Taper angle is one of the effective methods to reduce the dragload and downdrag of piles under the surcharge load. The model tests on the tapered pile and uniform cross-section pile embedded in sand were carried out under the surcharge load. The values of dragload and downdrag of piles versus the surcharge loads were measured. Based on the concentric cylinder shearing theory, a simplified theoretical model for calculating the dragload and downdrag of tapered piles with small taper angles under the surcharge load was proposed considering the angle effect. The correctness of the developed theoretical model was validated through comparing with the model test results obtained in this study and previous literature. Then the parametric studies of the taper angle, surcharge, strength and modulus of soil were discussed. It is shown that the tapered pile with the taper angle of 3° can reduce approximately 65% of the maximum dragload value and 30% of the downdrag value compared with a uniform cross-section pile. The value of downdrag can be decreased by approximately 50% compared with a uniform crosssection pile in the same average pile diameter. 相似文献
12.
刘一 《广东技术师范学院学报》2007,(3):16-18
基于光束传播法(beam propagation method,BPM),提出了聚合物光纤在受到拉力和压力产生形变的情况下的光传输的理论分析模型,模拟计算了光纤受拉力作用时形变区域的光强传输情况. 相似文献
13.
大学英语写作作为四项基本技能之一备受关注。尤其在近几年，人们更多关注英语中的各种考试试题并对其进行了大量的研究且取得了令人瞩目的成就。但不可否认，在学生的写作中语篇连贯仍是一个突出的问题。而逻辑连接词的正确恰当的使用是达到语篇连贯的手段之一。为此，本文将着重介绍逻辑连接词在议论文中对句子的连贯作用，并分析了学生们在使用过程中所存在的问题。 相似文献
14.
A novel quantum dots (QDs) optical fiber amplifier was proposed and demonstrated. It was fabricated by dipcoating the PbSe
QDs doped sol onto the taper region of fiber coupler. The PbSe QDs was synthesized according to a colloidal method. A lower
refractive index sol was also synthesized as the host of PbSe QDs. A standard single mode fiber was used to make the fusion
tapered fiber coupler which had double input and output ports. With the simple structure, a signal and a pump can be injected
into the amplifier and excite the PbSe QDs through evanescent wave. The experimental results indicated that the amplified
light wave was observed at 1 550 nm wavelength with 980 nm wavelength laser diode as pump. 相似文献
15.
采用有限元分析方法考察梁和柱的截面尺寸、角型连接件尺寸、铆钉直径及端距等对节点性能的影响,根据计算得到的弯矩-转角曲线拟合出三参数模型中形状系数n 值的近似计算公式。结果表明,柱翼缘厚度和角型件厚度对节点初始刚度和极限承载力影响显著,梁高和铆钉端距的影响次之。形状系数建议公式计算结果与试验结果吻合较好,可为该类连接节点设计方法提供理论依据。 相似文献
16.
This paper presents a method to create concept models for the tapered thin-walled tubes using beam elements and spring elements. Developed concept tapered beam models with different taper angles and cross sections are compared with those detailed models through impact analyses. Important crash results are recorded and compared, and the relatively good agreement is achieved between these analyses. Concept modeling steps are illustrated in detail, and a general concept modeling method for such thin-walled tubes is summarized and presented. 相似文献
17.
The intensity distribution of depolarized field in the focal region of a high numerical-aperture optical system was investigated and found that the depolarization effect is tunable by the plate. The depolarization effect gains with the increase of the inner convergence angle of the phase plate, goes through a dramatic descent when the angle is larger than 30° and begins to come back when the angle reaches a threshold of respectively 60°and 65° for the orthogonal diffractive field and the longitudinal diffractive fields. This reveals two convergence points where the depolarization effect is the strongest and weakest, respectively, suggesting that the pure phase plate can be a promising method for altering depolarization diffractive fields and constructing optical instruments. 相似文献
18.
A temperature sensor is demonstrated and fabricated by coating the single-mode tapered optical fiber with temperature-sensitive silicone rubber. It works on the change of the evanescent fields in the tapered optical fiber. Small changes in the refractive index of coating film greatly influence the power of evanescent fields, which modulate the transmission optical power in the waist region. The range of temperature measured is from 20°C to 70°C. The results show that the temperature sensor has high temperat... 相似文献