波导
- 与 波导 相关的网络例句 [注:此内容来源于网络,仅供参考]
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Combining the definition of CWT and the derivative property of convolution, we constructed a general method to calculate the approximate derivative of signal through CWT by using the first and second derivative of Gaussian function, Haar, and the first derivative of three-order-Spline function as wavelets. As compared with the other approaches of calculating derivative, which include the numerical differentiation, polynomial filters, Fourier transform, and the recently proposed DWT method, fast calculation and simple mathematical operation were remarkable advantages of CWT method. For the signal corrupted by severe noise (Signal-toNoise Ratio=5), the satisfactory results could also obtained via CWT method through appropriately adiusting the dilations.
在此基础上,(1)结合连续小波变换的特点和卷积的微分性质,提出了使用Gaussian函数的一阶和二阶导数,Haar和三次样条函数的一阶导数作为小波函数的连续小波变换计算信号近似导数的一般性方法,与其他导数计算方法(包括数字微分法,多项式滤波法,Fourier变换法和离散小波变换法)相比,本法简单便捷,计算速度快,对于噪声含量较高的信号(S/N为5),只要适当调节尺度即可获得比较满意的结果。
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Though comparing Canny operator and center B spline dyadic wavelet, the following conclusion is proven in this dissertation: a Center B spline function has tight support and Canny operator hasn't. b Center B spline function asymptotic convergence to Gaussian function and the derivative of Center B spline function asymptotic convergence to Canny operator. c The derivative of fourth order center spline B function is more suitable as a optimal edge detector than Canny operator. d Center B spline function can balance the smoothing and approximation of original data, and the fourth center B spline function is the only optimal solution of two order smoothing problem. e The error between the valve of time-frequency uncertainty of the fourth center B spline function and the lower bound of time-frequency uncertainty does not exceed 0.143% of the lower bound. f The derivative of center spline B function can construct a stability dyadic wavelet and can give a fast algorithm for multiscale edge detection, but Canny operator can do neither.
作者给出了Canny算子与中心B样条二进小波严格的比较证明,得出如下结论:a中心B样条函数具有紧支集,Canny算子不具有紧支集。b中心B样条函数的极限收敛于高斯函数,中心B样条函数的导数收敛于Canny算子。c四阶中心B样条函数的导数比Canny算子更接近最佳边缘检测滤波器。d中心B样条函数比高斯函数更能兼顾对原函数平滑和逼近的折中要求,并且四阶中心B样条函数是二阶逼近问题的唯一最优解。e四阶中心B样条函数的时频测不准关系值与时频测不准关系下界的逼近误差不超过0.143%。f中心B样条函数的导数可以构成稳定的二进小波,存在快速的多尺度算法;而Canny算子不构成稳定的二进小波,无法给出快速的多尺度算法。
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For a heterogeneous elastic solid consisting of two homogeneous layers, three homogeneous layers whose shear wave velocities increasing with depth, or three homogeneous layers whose interlayer has high velocity, if there are multi-mode dispersion curves, the phase velocity V〓 of the first mode will close up to the Rayleigh wave velocity of the bottom layer when frequency f→OHz, and V〓 of the first mode will close up to the Rayleigh wave velocity of the top layer when f→∞.
由多导波模式的相速度频散曲线还可知,对于二层固体介质、结构层的横波速度随深度而递增的三层固体介质、含硬夹层的三层固体介质而言,若频率f→OHz,其基阶模式的瑞利波相速度V〓→V〓(V〓为最底层介质的瑞利波速度);若f→∞,其基阶模式的V〓→V〓(V〓为最上层介质的瑞利波速度);因此,随着频率f逐渐升高,野外实测的瑞利波相速度V〓曲线应该主要为基阶导波模式。
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Therefore the dispersion curves obtained in the field are primarily consisted of the first mode. For a heterogeneous elastic solid consisting of three homogeneous layers whose interlayer has low velocity, the phase velocity V〓 of the first mode will also close up to the Rayleigh wave velocity of the bottom layer when frequency f→OHz, but V〓 of the first mode will close up to the shear wave velocity of the interlayer when f→∞, and there is a cut-off frequency at high frequency region for the first mode and V〓 close up to the compressional velocity of interlayer when interlayer is liquid.
当三层固体介质中存在软夹层时,若f→OHz,则其基阶模式的相速度V〓→V〓(V〓为最底层介质的瑞利波速度);若f→∞,其基阶模式V〓→V〓(V〓为中间层介质的横波速度);若三层介质中存在液体夹层,当f→OHz时,基阶模式V〓→V〓,而基阶模式在高频段存在一个截止频率,截止频率处的瑞利波速度V〓→V〓;由此可判定,野外实测的相速度频散曲线不仅有基阶导波模式,同时还应有高阶导波模式波的存在,接收信号中存在模式间的跳跃,因此频散曲线会产生"之"字形现象。
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Results:①The electrotonic modulation of T wave inversion was V1~V2V5~V6 in the right ventricular apical pacing group, and with T wave inversion in leads Ⅱ,Ⅲ, aVF, and without ST segment changes.
对74例由不同原因所致右胸导联T波倒置患者常规12导联心电图T波倒置的分布规律、倒置的深度以及是否同时伴有ST段改变、其它导联的T波倒置及其演变过程进行分析。
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It is shown that its working frequency and linear growth rate are higher than thatof common Cerenkov FEL,and for the same injection current,the linear growth rate of thissvstem and common Cerenkov FEL either decrease with increase of the gap between the dielectricand electron beam or there is an optimum gap value corresponding tO the maximum growth rate.
发现在入射电流和波导结构一定时,该系统和普通切伦柯夫自由电子激光器的增长率并不是随随电子束与介质的间距的增加而减小,而是存在一个最佳值。
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Cherenkov radiation in a plasma-filled dielectric coaxial waveguide.
填充等离子体的介质同轴波导中的切伦科夫辐射。
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The total solar eclipse has brought the VLF phase to delay obviously. The mechanism of the influence of total solar eclipse on the propagation of VLF signal is discussed.
讨论了日全食对VLF信号传播影响的机理,并用&波导模&理论对这种影响进行了理论计算。
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Which founded on 1st January 2003, SAGEM Mobiles Ningbo Co., Ltd is a joint venture of the leading French mobile telephone manufacturer SAGEM and Ningbo Bird Co.
成立于2003年1月1日,由欧洲著名移动电话制造企业法国萨基姆集团与宁波波导股份有限合资设立,2008年成为欧洲萨基姆集团的全资子。
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Microscopic characteristics of cladded crystal fiber are analyzed by X-ray diffraction, Laue X-ray diffraction and scanning electron microscopy, it is found that magnesium-ion indiffusion does not affect the single crystal structure and the domain structure of the magnesium diffused crystal fiber. It is found for the first time that MgO-rich layer in the magnesium diffused LiNbO〓 surface layer exhibits the crystal structure of an unknown compound from the Li-Mg-Nb-O ternary system and MgNb〓O〓. It is proposed for the first time that this unknown compound and MgNb〓O〓 in MgO-rich layer are the real sources of magnesium-ion indiffusion LiNbO〓. Their appearance indicate that MgNb〓O〓 is in the surface layer of MgO-rich layer, the unknown compound is in the subsurface layer and beneath where the MgNb〓O〓 is located, and these compounds have obviously preferred orientation.
通过镁离子内扩散法,首次在国内实现了具有阶跃和抛物折射率分布的c轴LiNbO〓单晶光纤和a轴Nd:MgO:LiNbO〓单晶光纤的芯—包层波导结构,为我国在该项目的研究填补了空白;建立了晶纤损耗的测量系统,提出了利用单模石英光纤作为晶纤入射光耦合器的思想;通过对晶纤损耗的测量,得到了包层晶纤比未包层晶纤损耗降低约14倍的好结果,并实现了低次模传输:对经镁离子内扩散实现包层后的晶纤的微观特性,利用X射线衍射,劳厄照相和扫描电镜表征发现,晶纤并不因镁离子的内扩散而影响其单晶结构和镁的扩散层畴的变化。
- 推荐网络例句
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We have no common name for a mime of Sophron or Xenarchus and a Socratic Conversation; and we should still be without one even if the imitation in the two instances were in trimeters or elegiacs or some other kind of verse--though it is the way with people to tack on 'poet' to the name of a metre, and talk of elegiac-poets and epic-poets, thinking that they call them poets not by reason of the imitative nature of their work, but indiscriminately by reason of the metre they write in.
索夫农 、森那库斯和苏格拉底式的对话采用的模仿没有一个公共的名称;三音步诗、挽歌体或其他类型的诗的模仿也没有——人们把&诗人&这一名词和格律名称结合到一起,称之为挽歌体诗人或者史诗诗人,他们被称为诗人,似乎只是因为遵守格律写作,而非他们作品的模仿本质。
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The relationship between communicative competence and grammar teaching should be that of the ends and the means.
交际能力和语法的关系应该是目标与途径的关系。
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This is not paper type of business,it's people business,with such huge money involved.
这不是纸上谈兵式的交易,这是人与人的业务,而且涉及金额巨大。