共查询到19条相似文献，搜索用时 125 毫秒
1.
吴丽双 《泉州师范学院学报》2006,24(6):19-23
通过实验研究了锥形聚合物光纤(POF)输出端光场强度分布呈现中心强、周边弱的模式分布特征,无论激光从大端输入、小端输出还是从小端输入、大端输出,都观察到小端的高阶模相对光强度明显低于大端,证明了锥形POF可以使大芯径POF和小芯径石英光纤的过渡连接得到良好的匹配.分别以大小端作为输入端口,研究了圆锥角度以及耦合长度对过渡器的光功率传输效率的影响,得出了POF过渡器最佳圆锥角度.yh 相似文献
2.
车床上的小滑板是纵向微量移动控制滑板,它可以用来控制被加工工件台阶长度、沟槽位置等,也可以转动小滑板车削圆锥体。根据笔者多年的实习教学体会,得出了小滑板的另一妙用,即根据转动小滑板车削圆锥体的原理,巧用小滑板车削高精度工件的外圆尺寸或孔径尺寸。具体方法如下:利用转动小滑板车削圆锥体的原理,把小滑板顺时针(或逆时针)转动一个角度,其角度等于锥度1∶50的角度,根据锥度原理:2tanα/2=D-dL=1∶50∴α/2=34'23″从理论上讲,锥度1:50是指中滑板不动,小滑板行程50mm,锥体大小端直径相差为1mm。例如:以小滑板刻度为0.05mm为例,当… 相似文献
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工程机械设计加工过程中 ,经常采用小锥度渐开线花键联接。在插齿机上加工小锥度渐开线花键 ,经常是在床身上垫一斜铁 ,使刀具主轴与工作台倾斜。这种办法需将插齿机改装成专用机床 ,操作琐 ,设备利用率低 ,不利于各种锥度加工 ,采用制造专用凸轮的加工方法 ,无需改装机床 ,只需更换凸轮 ,便可方便、快捷地加工小锥度渐开线花键。一、工作原理一般插齿机上的让刀凸轮 (如图 1)所示 ,其中 :ａａ′—工作部分 (等半径曲线 ) ;ＣＣ′—让刀回程部分 (等半径曲线 ) ;ａＣ及ａ′ｃ′让刀部分 (不等半径曲线 ) ;其工作部分半径不变可保证插出直齿… 相似文献
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良好的板形对高磁感取向硅钢十分重要,森吉米尔轧机的一中间辊锥度辊型对2号浪、边浪等钢带边部板形有重要影响。分析研究了一中间辊锥度在轧制过程中的窜辊位置与辊型对板形的影响过程,计算出最佳窜辊位置;同时分析了一中间锥度辊型在轧制过程中的磨损规律,以控制HiB钢带边部良好板形为目标,对一中间辊锥度辊型进行优化。 相似文献
6.
定理:设P为xa22 yb22=1上任意点,P点的两条焦半径为r1及r2;P点到原点距离为d.则:r1·r2 d2=b2 a2证明:设∠POF2=α,则∠POF1=π-α,在△POF2及△POF1中,由余弦定理有:r22=d2 c2-2ac·cosα①,r12=d2 c2 2dc·cosα②二式相加有:r21 r22=2d2 2c2(r1 r2)2-2r1r2=2d2 2c2※∵r1 r2 相似文献
7.
徐桂芳 《武汉工程职业技术学院学报》1997,(2)
二炼钢厂连铸机结晶器是连铸设备的心脏,在生产过程中,需定期停机用人工对结晶器的倒锥度进行调试、检测.设计一个结晶器倒锥度在线检测仪,实行结晶器倒锥度的在线检测,对节省人力物力,提高铸坯的产量将能起到很重要的作用.1 结晶器的重要性及结晶器倒锥度的计算 相似文献
8.
许绍元 《赣南师范学院学报》2011,32(6):19-20
研究半序锥度量空间中的压缩映象不动点问题,删去了正规锥的条件,同样得到了半序锥度量空间中压缩映象的不动点的存在性,这些结果改进了近期文献的相关结论. 相似文献
9.
普通车床加工大圆锥面在近几年的技能比赛中频频出现,而且精度要求较高,这给选手们带来了极大的挑战。如何利用转动小滑板车削大圆锥面,并且控制好精度,其关键是快、简、精、准地校正圆锥的角度。笔者从多年指导学生参加技能大赛的经验和生产教学实践出发,自制标准角度样板,并结合"百分表找正锥度法"进行深入探讨,总结出了"样板角度找正锥度法"的方法。教学实践表明,该方法有效提升了学生在车削大圆锥面时找正的速度与效率。 相似文献
10.
《中国现代教育装备》2002,(12)
近日达特电子(GCI)公司宣布,其塑料光纤(POF)生产厂将于12月中旬完成,装修和设备安装调试将在明年4月前结束,然后正式投入POF生产,预计年产塑料光纤达5万公里。 GCI塑料光纤生产厂位于河北省燕郊开发区,占地面积30亩。这一塑料光纤项目填补了国内宽带接入网系统设备制造的一项空白,为宽带接入市场增添了一项极富竞争 相似文献
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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.
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
13.
通过分析锥形短桩与土相互作用的特性，在受水平和垂直荷载时锥形短桩的承载能力、设计施工及技术经济对比，阐述了锥形短桩在提高单位承载力、降低成本、加快施工速度、土地的合理使用和可持续开发方面的优势。 相似文献
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利用智能微粒群算法(PSO)优化设计少片变截面弹簧代替原等截面板簧.文章通过ANSYS对其静态和动态特性进行有限元仿真分析,结果显示,在满足悬架性能条件下,质量比原板簧减轻了约31%. 相似文献
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In this paper, a novel surface-enhanced Raman scattering (SERS) sensor combined with fused biconical taper fiber (FBTF) and
film coated with silver sols is proposed. This structure is designed to significantly increase the SERS active surface when
the length of the taper is increased and the radius is reduced, since the penetration depth is inversely proportional to the
taper radius and proportional to the taper length according to the fiber-optic evanescent-wave theory. Based on the SERS sensing
principle, the feasibility of FBTF sensor is analyzed in this paper. As a result, the Raman spectrum of R6G is obtained from
the fused biconical taper zone surface coating with the silver sols in our experiments. The detected concentration is up to
10−7mol/L. 相似文献
16.
程森旺 《南昌教育学院学报》2010,25(1)
现行高中教材中的圆锥曲线既是教材的重要的基本内容,也是解决许多问题的一种方法。本文通过实例,从求解离心率、最值和轨迹等问题方面,讨论了圆锥曲线定义在解题中的重要性以及它的广泛应用。 相似文献
17.
卢媛媛 《黄冈师范学院学报》2004,24(6):69-70,83
阐述了校园网故障的诊断应从故障现象入手．以网络诊断工具为手段获取诊断信息．从而确定网络故障点．查找出问题的症结．排除故障． 相似文献
18.
Yan Jiang Jing Zhao Hui-jing Qi Xiao-lin Li Shi-rong Zhang Daniel W. Song Chi-yang Yu Jian-gang Gao 《Journal of Zhejiang University. Science. B》2013,14(4):318-324
Busulfan/cyclophosphamide (Bu/Cy) conditioning regimen has been widely used to treat cancer patients, while their effects on major internal organs in females are not fully understood. We treated female mice with Bu/Cy, and examined the histopathology of major internal organs on Day 30 after the treatment. The results show that Bu/Cy treatment affected the ovaries most extensively, while it had less effect on the spleen, lungs, and kidneys, and no effect on the heart, liver, stomach, and pancreas. To better understand the effect of Bu/Cy on the ovaries, we counted follicles, and determined the levels of ovarian steroids. The Bu/Cy-treated mice showed a reduction of primordial and primary follicles (P<0.01) on Day 30 and a marked loss of follicles at all developmental stages (P<0.01) on Day 60. Plasma levels of estradiol and progesterone in Bu/Cy-treated mice decreased by 43.9% and 61.4%, respectively. Thus, there was a gradual process of follicle loss and low estradiol in Bu/Cy-treated mice; this is a profile similar to what is found in women with premature ovarian failure (POF). The Bu/Cy-treated mice may serve as a useful animal model to study the dynamics of follicle loss in women undergoing POF. 相似文献
19.
刘铁禄 《天津职业院校联合学报》2006,8(2):22-24,33
利用计算机辅助设计给出了一种新的圆锥、圆柱正变相贯线最右点的求解方法。原有的方法求解圆锥、圆柱正变相贡的最右点，常利用侧视图中圆柱的积聚性，过锥顶作积聚圆的切线，再求出该切点在V面的投影，但这一方法求出的并非准确的最右点。利用解析方法对新方法进行分析验证。 相似文献