谱

Digitization is a trend which can be applied in MRI spectrometer with high performance and low cost.

应用数字化技术是谱仪发展的一个重要方向，它在提高谱仪的性能和功能的同时，还简化了谱仪结构，降低了设计成本。

There are many noise sources in measuring the seismometer transfer function, the main noise sources are investigated. The method of cross-special analysis is presented, flow process diagram of computing is given, the algorithms are discussed in detail, such as low-pass digital filter, computing of seismometer transfer function initial values, time domain convolution, bilinear transformation, estimation of power spectrum and cross-spectrum, window functions and preprocessing of measuring data etc.

在地震计传递函数测试过程中的存在多中噪声，本文分析了主要的噪声来源；介绍了用互谱分析方法测试地震计频率特性的基本原理和方法；给出采用该方法确定地震计传递函数的算法流程图；并对计算过程中采用的低通滤波器、地震计传递函数的初值确定方法、卷积运算方法、自谱和互谱估计、采用的窗函数和测试数据的预处理进行了详细讨论。

The complete sequence-specific assignments of proton resonances in the 1H-NMR spectra of SHL-I, a lectin isolated from the Chinese bird spider Selenocosmia huwena, is described.

描述了从虎纹捕鸟蛛毒液分离的凝集素SHL－I的核磁共振氢谱谱峰的完全归属。通过分析二维DQF－COSY，COSY，TOCSY和NOESY谱，鉴别出全部32个氨基酸残基自旋体系。

The aroma components of blood orange fruit were extracted by headspace solid phase microextraction and investigated by gas chromatography-mass spectrometry with two GC columns of different polarity(HP-5 and DB-WAX).

采用顶空固相微萃取对血橙的香气成分进行提取，用两个不同极性的色谱柱(HP-5和DB-WAX)进行分离，利用气相色谱-质谱联用技术对香气成分进行分析。

In the fourth chapter, firstly it introduces the Boolean functions algebraic expressions of the 2-value clock-controlled stop-and-go generator and Gunther generator. It reveals the balanced property of the two kinds of Boolean functions, and studies the Walsh cycle spectrum and the autocorrelation function. It also obtains the coincidence rate of their output sequences with affine sum of some bits of input sequences, and analyzes their ability of resisting the best affine approximation cryptanalysis and differential cryptanalysis. Secondly, we properly present a new definition of the Best Affine Approximation, namely BAA on the Boolean vector functions, followed by the spectral characteristic of such defined BAA attacks through using the decomposition formula of the union distribution for random variables. A lower bound of such BAA attacks is proposed. Finally, we also study the spectral characteristic of the second kind of nonlinearity of Boolean vector functions, followed by a higher bound of such nonlinearity. Furthermore, the limited relationship between the second kind of nonlinearity of Boolean vector functions and the linear structure of the linear combination of every component is analyzed.

在第四章中，首先给出了2值密钥流"停走生成器"和"衮特生成器"中实际存在的布尔函数的代数表示，揭示了这两类布尔函数的平衡性，随后研究了它们的Walsh循环谱和自相关函数等，得到了它们的输出序列与输入序列中的某些bit的仿射项的符合率，分析了它们抵抗最佳仿射逼近攻击和差分攻击的能力；其次，我们合理地给出了布尔向量函数最佳仿射逼近的新定义，利用布尔随机变量联合分布的分解式考察了相应的谱特征，并给出了布尔向量函数与其最佳仿射逼近的符合率的一个下界；最后，我们还考察了布尔向量函数第二类非线性度的谱特征，给出了布尔向量函数第二类非线性度的一个上界，并揭示了布尔向量函数第二类非线性度与其各个分量的线性和的线性结构之间存在的制约关系。

Three kinds of mass attenuation coefficient have been used, which are the monoenergetic MAC at the mean energy of the MC simulated spectrum, the effective MAC of the Born approximation formula spectrum and the effective MAC of the MC simulated spectrum.

在密度提取中使用了3种不同的吸收系数－MC谱光子平均能量对应的单能质量吸收系数、波恩近似公式谱有效质量吸收系数和MC谱有效质量吸收系数。

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 article,the frequency spectrum characteristic of the earthquake has been described by fourier amplitude spectrum, power spectrum and response spectrum.

而对地震动频率特性的描述则采用了已被工程界所广泛接受的反应谱、功率谱和傅氏谱。

Spectral element methods for partial differencial equation is introduced in this study from viewpoint of the collocation approximation of Chebyshev polynomial. Wave Equation and its space discretization are deduced. Two time integral methods, central difference method and implicit Newmark method, are introduced, and their stability and applicability are also discussed in some details. The significance of absorbing boundary conditions in spectral element methods for Aeroacoustics is explained, and Clayton-Engquist-Majda absorbing boundary conditions is emphasized and introduced, then the discrete scheme of this boundary conditions is deduced and applied to spectral element methods for wave equation.

本文从Chebyshev多项式逼近理论出发，详细介绍了谱元方法求解偏微分方程的过程；推导了流体中的声波动方程并在空间上对其进行了谱元离散；详细讨论了两种时间积分方法──中心差分法和Newmark方法，分析了它们的稳定性条件，并从理论上对比了两种方法的优缺点和适用范围；将吸收边界条件推广应用于谱元方法求解气动声学问题中，重点介绍了Clayton-Engquist-Majda吸收边界条件的原理和公式，推导了该吸收边界条件的变分形式，并将其引入波动方程的离散形式中。

The electrochemical impedance spectroscopy features and the resistance to corrosion of an epoxy coating containing the pigment of zinc chrome yellow have been studied with the aid of EIS and Fourier transform infrared spectroscopy analysis.

运用电化学阻抗谱和Fourier变换红外光谱研究了经过不同老化温度和老化时间处理的含锌铬黄防锈颜料的环氧酯漆在3.5％NaCl溶液中的阻抗谱特征，根据Fourier变换红外光谱和电化学阻抗谱中第二个时间常数出现的快慢及高频收缩情况来判断涂层的耐蚀性能，进而筛选老化工艺。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。