查询词典 density function

The density function theory B3LYP method with LANL2DZ basic sets is adopted to opt all possible geometrical structures of Tin (n=2~7) and to get the most stable structure. Then, the binding energy and Natural bond orbital of Ti clusters are calculated and discussed.

利用密度泛函理论中的B3LYP方法，选择LANL2DZ基组优化Tin(2~7)团簇得到各团簇的稳定结构，然后对稳定结构的束缚能及自然轨道进行分析。

In this thesis, we investigate theviability and electronic properties of ultrathin carbon naontubes, aswell as carbon nanotubes doped with boron and nitride atoms usingfirst-principles method which is based on Density Function Theory.

基于密度泛函的第一性原理，本文研究了小管径碳纳米管的稳定性和电子性质，并探讨了硼和氮掺杂对碳纳米管性能的影响。

Aiming at the problems of over-fitting and generalization for neural networks, the locally most entropic colored Gaussian joint input-output probability density function estimate is studied, and a new method by means of Chebyshev inequality is proposed to self-revise respectively according to every cluster.

针对神经网络的过拟合和泛化能力差的问题，研究了样本数据的输入输出混合概率密度函数的局部最大熵密度估计，提出了运用Chebyshev不等式的样本参数按类分批自校正方法，以此估计拉伸样本集，得到新的随机扩充训练集。

Given a finite training sample set, according to the proposal of establishing a Local Most Entropy probability density function to estimate the number of cluster a method for estimating 〓 is proposed, where a complicated method based on Maximum Likelihood Cross-Validation is replaced by Chebyshev inequality.

为改善BP算法的收敛速度慢、易陷入局部最小的问题，提出了带一类非线性特性动量项的变步长BP算法，构造了一个能自适应升降温的动量项非线性强度函数，在编程中又采用了有条件引入非线性特性动量项的措施，大大提高了搜索过程跳出局部极小、快速稳定收敛的能力。

In order to improve the validity of identifi cation of digital image origin and predetermine accurately threshold of identification,a new probability density function of generalized chi square distribution is constructed within0,1 for asymmetrical distribution of noise correlation.

为了提高鉴别数字图像来源的正确性，正确设置判别阈值，针对噪声相关性的非对称分布，在0，1区间构造了一个广义chi平方分布的新函数，并提出了一种利用广义chi平方分布来描述噪声相关性的非对称分布和利用广义高斯分布来描述噪声相关性的对称分布的新方法。

It is concluded by the comparison of the Power Spectrum Density Function estimated from design spectra that the spectral energies do not distribute uniformly within the frequency of engineering interest in Chinese codes. The remarkable spectral energies concentrate in the range of low and high frequency.

由各规范设计谱估计的功率谱密度函数的比较说明，我国某些抗震设计规范设计谱给出的设计地震动在工程感兴趣的频率范围内可能存在能量分布不均的问题，低频分量和高频分量与中等频率段相比相对显著。

Multi-attribute decision-making with risk ; joint density function ; fuzzy complementary judgment matrix ; interval number

风险型多属性决策；联合密度函数；模糊互补判断矩阵；区间数

A conditional probability density function of the SAR imaging systems is derived, These works lay a foundation for further research.

将SAR成象系统视为一个多元接入信息系统，在深入分析系统构成的条件下，求出该系统的传递概率密度函数。

The confidence of each region of target image is calculated according to its discriminative power between the tracking target and local background, and the target and candidate models are characterized by LBP feature probability density function weighted by region confidence and distance.

根据目标各区域对背景的区分能力不同，提出了目标各区域置信度的评价方法，用基于区域置信度及空间距离核加权的LBP特征概率密度函数，构造了目标及候选目标的特征模型。

1H NMR spectroscopic analysis of aromatic protons combined with theoretical analysis of molecular structures proved the existence of two rotational isomers at 300 K, as well as a rapid interconversion equilibrium at 330 K for both compounds Ⅰ and Ⅱ. However, only one conformer exists for compound Ⅲ and puerarin containing 7-phenolic hydroxyl instead of propyl in A-ring as the case of compounds Ⅰ and Ⅱ. Based on UV-Visible absorption data of neutral and basic solutions, and on the density function calculations, the 7-phenolic hydroxyl group in A-ring was found to be more acidic than the 4'-phenolic hydroxyl group in B-ring. The mechanism of derivation reaction and the structure-reactivity relationship of puerarin as an antioxidant were further discussed.

其中7-丙基葛根素Ⅱ属于新型取代衍生物；变温1H NMR和理论计算结果表明，在300 K时，葛根素和4'-丙基葛根素以单一构型存在；而7，4'-二丙基葛根素和7-丙基葛根素则存在两种核磁可分辨的旋转异构体，当温度升至330 K时，两种异构体可以相互转化；通过对比分析葛根素及其衍生物脱质子产物的紫外可见吸收光谱并结合理论计算，确定了A环上7位酚羟基比B环上4'位酚羟基先脱去质子，并由此进一步阐明了葛根素衍生化反应机理以及在抗氧化作用中可能的活性位点和结构活性关系。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了