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1.
微机通过接口电路自动控制红外光栅单色仪,对光纤材料进行零色散波长的精确测量。  相似文献   

2.
改进的对块零树编码压缩方法对超光谱数据压缩   总被引:6,自引:6,他引:0  
提出了对块零树的预测二值标量量化压缩编码方法,给出了压缩比公式,并应用此压缩编码实现了对超细光谱数据的压缩,该压缩编码方法既具有小波零树压缩编码高压缩比和宜于实时实现的特点,同时具有编码,解码速度快和易于实时传输等优点,实验结果表明,改进的对块零树编码压缩(IBBZTC)方法在不传输剩余误差的情况下,达到190倍的压缩比时,峰值信噪比仍然在30dB以上,压缩性能优于KL变换-静止图像压缩(KLT-JPEG),小波变换-矢量量化(WT-VQ),小波变换一零树矢量量化(WT-ZTVQ)和对块零树编码压缩方法。  相似文献   

3.
用E=1/2kA2求谐振系统振幅应注意的一个问题   总被引:1,自引:1,他引:0  
本文指出了用E=1/2kA^2求振幅A时,必须选择谐振系统的平衡位置作为谐振系统所有势能的零点,否则利用该式求出的振幅是错误的。  相似文献   

4.
In this letter we study fermionic zero modes in gauge and gravity backgrounds taking a two-dimensional compact manifold S2 as extra dimensions. The result is that there exist massless Dirac fermions which have normalizable zero modes under quite general assumptions about these backgrounds on the bulk. Several special cases of gauge background on the sphere axe discussed and some simple fermionic zero modes are obtained.  相似文献   

5.
Graf  G. M.  Hasler  D.  Hoppe  J. 《Letters in Mathematical Physics》2002,60(2):191-196
We show that the positive supersymmetric matrix-valued differential operator H = p x 2 + p y 2 + x 2 y 2 + x3 + y1 has no zero modes, i.e., H = 0 implies = 0. The result depends on a virial type argument for the corresponding supercharge. The model may be regarded as a simple relative of dimensional reductions of supersymmetric Yang–Mills theories.  相似文献   

6.
林琼桂 《大学物理》2011,30(2):1-4,24
总结了一般短程中心力场低能散射的4种可能结果:1)微分截面有限且各向同性;2)微分截面有限且显著各向异性:3)零能共振;4)冉绍尔一汤森(Ramsauer-Townsend)效应.详细分析了各种结果出现的条件,指出其与零能解形式密切相关.计算了若干简单势场下的具体结果,印证了一般结论.  相似文献   

7.
徐兴碧 《物理实验》2004,24(10):22-23
大家知道,在磁场中的运动电荷不管受不受其它外力作用,洛仑兹力总是不做功.因为洛仑兹力总是跟速度方向垂直,它只改变速度方向,不改变速度大小.但在有些实际问题中,经常需要将洛仑兹力巧妙地进行分解,运用在某个方向上做功或者与其它外力在某个方向上叠加产生加速度来分析处理问题,现举例说明。  相似文献   

8.
徐晓梅  李云德 《大学物理》2004,23(11):25-27
在柱坐标系中,求出了绝对零度情况下近理想玻色气体涡旋态的波函数和能量的近似解析形式.  相似文献   

9.
介绍用摸拟电路与数字电路两种方法来消除输出信号变化对位置精变的影响。  相似文献   

10.
热处理对Li2O-Al2O3A-SiO2系统玻璃性质的影响   总被引:1,自引:0,他引:1  
测量了线性升温热处理后Li2 O Al2 O3 SiO2 系统零膨胀微晶玻璃V0 2的性质变化。在一个较小的温度区间内 ,玻璃物理性质由于相变而出现显著变化。折射率增加 175× 10 -4、密度增加 0 .0 94g/cm3 、热膨胀系数降低4 1× 10 -7/℃、努普 (Knoop)硬度增加 18.6MPa、线收缩达 1.12 %。短波区透射率随着热处理温度的升高先出现下降而后再次上升。实验结果为大尺寸微晶玻璃毛坯的晶化工艺过程提供有实用意义的建议  相似文献   

11.
If ordinary views on particle structure are introduced in a simple classical particle model in replacement of the point particles of standard use in stochastic electrodynamics, it can be shown that an internalZitterbewegung induced by the zero-point field background gives rise to a Brownian movement for the whole particle with a diffusion constant of the form D = /2mD , where mD is a modeldependent mass. Since the days of Madeleung and Fuhr brownian behaviour has often been associated with quantization. We discuss this from the viewpoint of stochastic electrodynamics.  相似文献   

12.
In this paper we have analyzed the performance of different modulation formats for a four-channel WDM CATV system using optical ad drop multiplexers and the impact of frequency and wavelength on Q-value, and eye opening is observed for added and dropped channels at different lengths.  相似文献   

13.
1 IntroductionDigitizedimagesneedstoring ,transmittingandprocessing ,anddatacompressionisusuallyimplemented ,obtainingthebitrateandmaintaininganacceptablefidelityorimagequality .Compressioncanbeachievedbytransformingthedata,projectingitonabasisoffunctions…  相似文献   

14.
《Current Applied Physics》2015,15(4):520-527
We present a comprehensive analysis about the transport properties of a quantum dot (QD) system with a side-coupled Majorana zero mode. Our calculation result shows that when the coupling manners between the two leads and QDs are identical, the local Andreev reflection and the interlead normal tunneling have the same magnitude at the zero-bias limit. Accordingly, the zero-bias conductance value is always equal to e2/2h, which is exactly one half of the resonant-tunneling conductance. This result is independent of the level number and the level distribution in the single-QD case, and in the coupled-QD case it is irrelevant to the geometry of the QD molecule. The universal transport property is a powerful evidence for the feasibility to detect the MBSs based on a QD circuit. This result also means that the QD condition is not a key factor to achieve the detection. On the other hand, if the decoupling phenomenon appears, the Majorana zero mode may play a trivial role in contributing to the conductance property.  相似文献   

15.
提出了一种带有陷波单元的新型高温超导滤波器设计结构,在输入、输出馈线附近设置陷波单元对特定频率产生陷波作用,在滤波器的传输特性上成传输零点,提高了滤波器设计的灵活性,基于这种新型结构设计了高边缘陡峭度滤波器和邻频双通带滤波器.  相似文献   

16.
高天琪  魏斌  衡勇 《中国物理 B》2017,26(5):58503-058503
This paper presents a novel microstrip feedline structure to introduce an extra and controllable transmission zero(TZ)with high rejection for a narrowband filter. This structure loads a reconfigurable capacitor at the end of the input feedline without changing the main structure of the filter. The capacitor is recognized by a 2-bit inter-digital capacitor array. The asymmetrical microstrip feedline structure is suitable for multiple-pole filter designs. A low-loss six-pole high-temperature superconducting bandpass filter with a reconfigurable TZ is designed and fabricated. The center frequency of the filter is 5.22 GHz with TZ at the lower stopband. The TZ can be tuned among four different states. The out-of-band rejection at the TZ frequency is higher than 90 d B, and the insertion loss is lower than 0.92 d B. The measured results are consistent with the simulations.  相似文献   

17.
应用激光技术检查火炮的零位和零线   总被引:3,自引:0,他引:3  
在火炮(包括地炮,高炮)的零位、零线检查中,一直停留在吊垂线、人眼瞄准等费时费力的传统方法中,速度慢,误差大,夜间和野外条件下无法实施,而且由于垂线较高,危险性较大。利用“激光延展技术”代替铅垂线,用激光束瞄准代替人眼瞄准。并在零位检查中利用CCD探测技术,使“激光垂线”和炮口十字线通过CCD摄像头形成的像在显示器上显示出来。该方法可使火炮校正速度提高5倍左右,精度提高一倍。  相似文献   

18.
The phonon spectra for liquid Li and Na have been computed through the phenomenological model of Bhatia and Singh for disordered systems like liquids and glasses and the obtained results have been compared with the available data obtained by inelastic neutron scattering (INS) and inelastic X-ray scattering (IXS) experiments. The effective pair potentials and their space derivatives are important ingredients in the computation of the dispersion curves. The pair potentials are obtained using the pseudo-potential theory. The empty core model proposed by Ashcroft is widely used for pseudo-potential calculations for alkali metals. But, it is thought to be unsuitable for Li because of its simple 1s electronic structure. However, it can be used with an additional term known as Born-Mayer (BM) core term. The influence of the BM core term on the phonon dispersion is discussed. The same pseudo-potential formalism has been employed to obtain the dispersion relation in liquid Li0.61Na0.39 alloy. Apart from the phonon spectra, the Ashcroft-Langreth structure factors in the alloy are derived in the Percus-Yevick approximation.  相似文献   

19.
介绍用绝对零度球体与压力传感器和温度传感器配合,在定容条件下测量气体的压强与温度,采用外推法估算理想气体可以达到的最低温度(绝对零度)的摄氏温度值,替代原先用玻璃管测体积和水银温度计测温度。使用新的绝对零度实验装置,可以更明显地观察分析热力学现象,并使测得的绝对零度值较为精确。  相似文献   

20.
于春霖  张浩 《物理学报》2020,(7):265-273
Majorana准粒子是凝聚态物理版本的Majorana费米子.由于Majorana准粒子间的交换操作服从非阿贝尔统计,并基于此可构建更稳定的量子计算机,近年来在凝聚态物理界引起广泛关注.为帮助初学者快速理解Majorana准粒子的形成机理,本文回顾了在一维超导体-半导体异质纳米线系统中Majorana准粒子模型的提出和理论演化过程,介绍Kitaev链模型并分析了模型中各要素所起的作用.还介绍了典型Majorana器件的构成和测量方法,并结合最新的实验进展对探测到的零能电导峰进行了分析和述评.最后对超越一维系统的超导体-半导体异质系统的实验前景进行了展望.  相似文献   

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