查询词典 comparison spectrum

In the aspect of the study of the application of HHT method, This dissertation has done three part of jobs: first, the Elcentro strong ground motion which is in common use in earhtquake engineering is analyzed by HHT method, getting its amplitude-frequency-time distribution and the comparison between the HHT marginal spectrum and Fourier spectrum is also made; second, the typical nonlinear system defined by the Duffing equation is analyzed by HHT method, getting its numerical value's amplitude-frequency-time distribution and the comparison between the HHT marginal spectrum and Fourier spectrum is also made; third, define the stationary degree of non-stationary signals making use of 3-D time-frequency spectrum and marginal spectrum, the stationary degree curve of Elcentro seismic recording is protracted according to its defining formula, the stationary degree curve of Elcentro seismic recording which change with time is protracted according to similiar definition.

在HHT方法的应用研究方面，本文做了三部分的工作：首先，利用HHT方法分析了地震工程中常用的Elcentro非平稳强震记录，得到了该记录的振幅－频率－时间分布特性，并将得到的边际谱与傅立叶谱做了比较；其次，应用HHT方法分析了典型的非线性系统－Duffing方程，得到了该方程数值解的振幅－频率－时间分布特性，并将得到的边际谱与傅立叶谱做了比较；最后，利用三维时频谱与边际谱定义了非平稳信号的平稳度，并依照其定义式绘制了Elcentro地震波记录的平稳度曲线，依照类似与依赖与频率变化的平稳度定义，初步尝试编程绘制了Elcentro地震波随时间变化的平稳度曲线。

To further understand and correctly master the notion of marginal spectrum in Hibert-huang transform, the linear property of marginal spectrum is demonstrated, an mistake to the notion of marginal spectrum in some documents is pointed out, and a new viewpoint about the essential difference between marginal spectrum and Fourier frequency spectrum is put forward by which the amplitude of Fourier frequency spectrum only represents the probability that a frequency objectively exists in a signal while the amplitude of marginal spectrum decides whether a frequency objectively exists in a signal.

为了深入理解和正确掌握希尔伯特－黄变换（Hilbert-Huang Transform，简称HHT）中的边际讲概念，证明了边际谱的线性性质，指出了文献中对边际谱概念的一种误解，提出了边际普与Fourier频谱之间本质区别的一种的新观点，即Fourier频谱的幅值只能反映频率在信号中实际存在的可能性大小，而边际谱的幅值则能真实反映频率在信号中是否存在。

Aiming at this problem, the concept of the second order power spectrum was proposed based on the characteristic of the amplitude tune with periodical notch spectrum in thin layer and theoretically researched. The corresponding relationship between the thickness of thin layers and the maximum value of second order power spectrum was established. The theoretical criteria and method for the thickness estimation by second order power spectrum were given. The second order power spectrum map is made by the energy relationship between the thickness of thin layers and the second order power spectrum, and the time responding to strong energy on the map is the time of thin layer.

为此，从薄层振幅调谐具有周期性陷频谱特征出发，提出了二阶功率谱的概念，从理论上对薄层的二阶功率谱特征进行了研究，建立了薄层厚度与二阶功率谱极大值之间的对应关系，给出了利用二阶功率谱进行薄层厚度预测的理论依据和方法，即根据薄层厚度和二阶功率谱的能量关系制作二阶功率谱图，图上强能量团对应的时间即为薄层时间厚度。

This result can best be viewed as a quantum black hole version of the third law of thermodynamics. As a result of this area spectrum, the spectrum of M is discrete, bounded below, and can be made positive. Prom the physical point of view, the semiboundedness and positivity of the spectrum are very satisfying results: The semi-boundedness of the spectrum implies that one cannot extract an infinite amount of energy from the system, whereas the positivity of the spectrum is in agreement with the well-known positive-energy theorems of general relativity.

同时根据EMDA黑洞动力学，存在与面积谱对应的大于零且有下界的质量离散谱，从物理上来看，质量谱的半有界性意味着不可能从系统吸取无限的能量，而正定性则与广义相对论中的正能定理一致，也就说稳态轴对称EMDA时空的ADM能量总是大于零。

In this thesis, we use the Min-Max criterion and Parks-McClellan algorithm to design this optimal approximation error of spectrum. Moreover, we give constraint of this optimal spectrum to get the positive spectrum. Then the positive spectrum can be factored by Spectrum Factorization Theorem and can be realized by FIR system.

我们利用最小化最大误差指标，及Parks-McClellan演算法，设计出具有最佳误差的频谱，并对此频谱做限制式上的处理，来得到正数列频谱，并将所得到之正数列频谱利用分解理论做分解，并以FIR系统实现之。

Through simulation and computation, some critical values to contral interferences are obtained. These values have directive significance to the design and deployment of WRAN.(4) New methods to measure and analyze spectrum aredevelopedAccording to the shortages of previous spectrum measurements, new methods to measure spectrum occupancy in wide-band and multi-point synchronously is proposed in this dissertation, and the tests last a whole week; the relativities of licensed services are considered when test points are selected. More importantly, data mining and in-depth analysis are carried out with the huge amounts of test data, and a channel analysis method using Channel Vacancy Duration and Service Congestion Rate are proposed. The spectrum relativities of 3-dimension in time, space and frequency are researched also. The correlativity between channel state and history information is discoved, and which will provide the scientific basis to channel modeling, spectrum analysis and decision of CR users.

4提出了频谱测量与分析的新方法针对以前频谱测量工作存在的不足，本文提出了多点同时广域频谱测量方法，测量工作持续了一周的时间，同时考虑了测量地点的选取和频谱授权业务之间的相关性；对测量得到的海量数据进行了数据挖掘和深度分析，提出了使用信道空闲时间(Channel VacancyDuration，CVD)和业务拥塞率(Service Congestion Rate，SCR)进行信道分析的方法，研究了频谱之间的时间、空间、和频率三维立体的相关性，发现了信道状态和历史信息的关联性，为CR用户的信道建模、频谱分析和决策提供了科学的理论依据。

The digital analysis of the three standard samples of the Al-based alloy with different content of Cu, and the probe into the quantitative analysis that employs the spectrums of Cu 510.55 nm and Fe 510.75 nm as the analysis spectrum and comparison spectrum, indicate the positive relationship between the content of copper and the intensity ratio of the analysis and comparison of spectrum.

对3种不同Cu元素含量的铝合金标准样品进行数字化分析测定，探索选用Cu 510.55nm谱线和Fe 510.75nm谱线分别作为分析谱线和比较谱线进行定量测定的方法，数据显示分析谱线和比较谱线的强度比值与Cu元素含量呈正比关系。

The digital analysis of the six standard samples of the Al-based alloy with different content of Cd, and the probe into the quantitative analysis that employs the spectrums of Cd 508.5 nm as the analysis spectrum, Cu510. 55 nm and Fe510.75 nm as comparison spectrum separately, indicate the positive relationship between the content of cadmium and the intensity ratio of the analysis and comparison of spectrum.

对6种不同Cd元素含量的铝合金标准样品进行了数字化分析测定，探索了选用Cd 508.58nm谱线作为分析谱线，分别选用Cu510.55nm和Fe510.75nm谱线作为比较谱线进行定量测定的方法，数据显示分析谱线和比较谱线的强度比值与Cd元素含量成正比关系。

The visible spectrum of Mo in Ti-based alloy was analyzed by a digital spectroscope. Mo 553.31nm and Ti 551.44nm were selected as spectral lines for analysis and comparison. Samples of Ti-based alloys with different Mo contents were analyzed quantitatively. The data indicated that the ratio of intensities between analytical spectrum and comparison spectrum has a positive relationship with the content of Mo.

使用数字化看谱镜对钛合金中钼元素可见光谱进行了分析测定，选用M0553.31nm和Ti551.44nm作为分析谱线和比较谱线，对不同Mo元素含量的钛合金样品进行了定量分析探索，数据显示分析谱线和比较谱线的强度比值与Mo元素含量成正比关系。

Second, From the internal comparison of linzhang dialect,I find that the difference from east to west is smaller and the difference is larger from south to north ,particularly the southern Zhanghe is affected by vicinity dialects, the tail is abundant and the suffixation of the northen Zhanghe is increasing under the influence of the Standard Chinese. The exterior comparison includes the comparison of the linzhang dialect vocabulary to that of the vicinity and that of the Standard Chinese. The comparison with the vicinity dialects reveals the ralationship of the Linzhang dialects with the vicinity dialects and inquire into its reason. Third, Through the comparison between the dialect and the Standard Chinese from the aspects of sallable, morpheme,affixation, I reveal the vocabulary-made characteristics of the Linzhang dialect---- to have abundant affix. Last, we divide the vocabulary in the Linzhang dialect into the Ancient Chinese words,the Medieval Chinese words,the Modern Chinese words,the Modern Chinese words by the historical view.

漳河北受普通话影响比较大，儿化现象比较突出；外部比较主要通过临漳与周围县，如安阳、魏县、磁县、成安县等，方言词汇的比较以及与普通话词汇的比较，揭示了临漳方言与周围县方言的亲疏关系，并探讨了其原因； 3、临漳方言词汇的构词特点，主要从构词的角度，从音节、语素、附加式构成几个方面与普通话进行了比较，突出了临漳方言词汇词缀构词的特点； 4、临漳方言词汇的历史层次是从汉语史的角度对词汇进行的分类研究，从词汇产生的时代划分出上古汉语词汇、中古汉语词汇、近代汉语词汇以及现代汉语词汇。

In the days of sailing vessels the crew were afraid they would be becalmed on the ocean.

在使用帆船的时代，船员们担心他们会因为无风而无法在海洋上航行。

As long as foreign donors pay the PA's salary bill, few expect a new intifada.

只要外国继续为巴权力机构的薪水买单，希望发动新暴动的人便寥寥无几。