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基于分子阵预处理的最小方差无畸变响应波束形成方法 被引量:4
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作者 武时龙 《探测与控制学报》 CSCD 北大核心 2018年第6期84-88,共5页
针对最小方差无畸变响应(MVDR)波束形成中背景噪声和旁瓣级对弱目标检测影响问题,提出了基于分子阵预处理的MVDR波束形成方法。该方法首先对线列阵接收数据进行分组处理;然后按搜索角度对各组数据进行相移、相加处理,得到一组新数据;最... 针对最小方差无畸变响应(MVDR)波束形成中背景噪声和旁瓣级对弱目标检测影响问题,提出了基于分子阵预处理的MVDR波束形成方法。该方法首先对线列阵接收数据进行分组处理;然后按搜索角度对各组数据进行相移、相加处理,得到一组新数据;最后按MVDR波束形成思想对该组新数据进行处理,可得到低背景噪声和旁瓣级波束。理论推导分析、数值仿真和实测数据处理结果均表明,该方法对线列阵接收数据进行了分子阵预处理,相比MVDR波束形成,有效提高了线列阵接收数据协方差矩阵中信号含有量和信噪比,输出背景噪声级和旁瓣级得到了10dB以上的改善,降低了背景噪声和旁瓣级对MVDR波束形成检测弱目标的影响,提高了MVDR波束形成对弱目标的检测效果。 展开更多
关键词 最小方差无畸变响应波束形成 分子阵预处理 旁瓣级 弱目标检测
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BLUP中分子血缘相关矩阵A逆阵的直接计算法
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作者 刘学洪 《中国奶牛》 北大核心 2002年第4期29-30,共2页
关键词 BLUP 分子血缘相关矩A逆 直接计算法 种畜
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基于子阵近场零陷权的联合波达方向估计方法 被引量:4
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作者 生雪莉 刘婷 +2 位作者 杨超然 郭龙祥 穆梦飞 《电子与信息学报》 EI CSCD 北大核心 2021年第3期727-734,共8页
针对海底长线阵在近场辐射声干扰及空间水平非均匀噪声下的远距离估计目标波达方向(DoA)问题,该文提出一种基于长线阵分子阵近场零陷权的联合目标方位估计方法。该方法将长线阵分解为多个高重叠子阵,对各个子阵利用零陷抑制技术去除近... 针对海底长线阵在近场辐射声干扰及空间水平非均匀噪声下的远距离估计目标波达方向(DoA)问题,该文提出一种基于长线阵分子阵近场零陷权的联合目标方位估计方法。该方法将长线阵分解为多个高重叠子阵,对各个子阵利用零陷抑制技术去除近场强干扰对目标探测的影响,再利用各子阵对远距离目标方位估计结果差异性小、非目标所在频率即噪声对应空间谱最大值随机的特点,空间频率方差加权综合各子阵的目标方位估计结果,从而抑制空间非均匀噪声,实现对远距离目标的探测。仿真结果表明,与长线阵常规波束形成、长线阵近场零陷常规波束形成、长线阵近场零陷传统多重信号分类方法相比,该文方法能够有效降低空间谱背景级60 dB以上,输出信噪比提高15 dB以上,具有较强的提高信噪比能力及较高的空间分辨力,因此具有较好的工程应用价值。 展开更多
关键词 波达方向估计 远距离探测 近场零陷权 非均匀噪声 分子阵
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有限采样下低频声源聚焦波束形成的定位研究 被引量:4
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作者 周泽民 倪明 《应用声学》 CSCD 北大核心 2010年第4期306-312,共7页
依赖于基阵协方差矩阵的算法,要求有足够样本容量来实现稳健的性能。针对常规聚焦波束形成在低频段分辨能力不足以及有限的数据长度,本文研究了一种基于最小方差无失真响应(MVDR)的重叠分子阵算法。仿真实验表明,重叠分子阵MVDR算法在... 依赖于基阵协方差矩阵的算法,要求有足够样本容量来实现稳健的性能。针对常规聚焦波束形成在低频段分辨能力不足以及有限的数据长度,本文研究了一种基于最小方差无失真响应(MVDR)的重叠分子阵算法。仿真实验表明,重叠分子阵MVDR算法在低快拍数、低信噪比情况下,稳健性优于全阵列MVDR算法。在海试数据中,利用一条孔径为109m的光纤水听器阵列,验证了该算法可以在低快拍数下对50m内低频段100~200Hz的目标实现分辨率为0.5m的近场定位。 展开更多
关键词 有限采样 聚焦波束形成 重叠分子阵 低频
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The FDTD Full Wave Analysis of Fractal Antennas
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作者 王宏建 高本庆 《Journal of Beijing Institute of Technology》 EI CAS 2002年第4期355-359,共5页
The full wave FDTD method was used to analyze the Hilbert and H fractal curves antennas. The computational results of the input impedance of Hilbert fractal antenna are in good agreement with the experiments in the do... The full wave FDTD method was used to analyze the Hilbert and H fractal curves antennas. The computational results of the input impedance of Hilbert fractal antenna are in good agreement with the experiments in the documents. The results also show that the self-similarity of the fractal structure leads to the multiplicity of resonances over some predetermined operating bandwidths of the antenna. Fractal geometries of Hilbert and H curves can be implemented to miniaturize the antenna, too. The results also show that the higher order fractal antenna leads to the more efficient reduction of the antenna size than the lower order one. Furthermore, the far field patterns remain almost the same as those of the dipole at their own resonant frequencies. 展开更多
关键词 FRACTAL ANTENNA FDTD
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High-Responsivity ZnS Schottky Barrier Photodiode Array for Ultraviolet Imaging
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作者 沈大可 韩高荣 +2 位作者 S.Y.Au 葛惟昆 I.K.Sou 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2002年第8期892-896,共5页
A different approach,using the molecular beam epitaxy (MBE)-grown ZnS-based Schottky photodiode technology,is applied to fabricate an 8×8 photodiode array.The micro-processing procedures of this photodiode array ... A different approach,using the molecular beam epitaxy (MBE)-grown ZnS-based Schottky photodiode technology,is applied to fabricate an 8×8 photodiode array.The micro-processing procedures of this photodiode array including standard photolithography,a number of metallisation,wet-chemical etching and SiO_2 deposition for insulation are developed.The detector is characterized to have a cutoff wavelength at 340 nm and the photo-responsivity measurements on the pixels result an ultraviolet (UV) response as high as 0.15 A/W,corresponding to an external quantum efficiency of 55% in the visible-blind spectral ranging from 400 down to 250nm.Imaging tests indicate that this array is able to capture the intensity profile of a given UV light source with reasonably good capability. 展开更多
关键词 ZnS-based Schottky barrier photodiode array MBE high-responsivity
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Modified molecular matrix model for predicting molecular composition of naphtha' 被引量:4
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作者 Kun Wang Shiyu Li 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2017年第12期1856-1862,共7页
To improve the naphtha composition prediction model based on molecular type homologous series matrix (MTHS), this paper puts forward a novel molecular matrix to characterize the naphtha composition and the norreal d... To improve the naphtha composition prediction model based on molecular type homologous series matrix (MTHS), this paper puts forward a novel molecular matrix to characterize the naphtha composition and the norreal distribution hypothesis to better describe the molecular composition distribution within each homologous series of the molecular matrix. Through prediction calculation of eight groups of naphtha samples and eight groups of gasoline samples, it is verified that the normal distribution hypothesis is more applicable than gamma distribution hypothesis for the prediction model. According to the prediction results of the samples, the restrain range of normal distribution parameters during model computing process is summarized. With the bulk properties of naphtha samples and the value range of distribution parameters as input conditions, this study utilizes the improved novel molecular matrix to predict the composition of naphtha samples. As the results show, the novel molecular matrix can predict more detailed composition information of naphtha and improve prediction accuracy with less unknown parameters. 展开更多
关键词 MTHS molecular matrix Distribution assumption Naphtha Molecular composition Prediction model
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Realization of Two-Qutrit Quantum Gates with Control Pulses 被引量:4
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作者 ZHANG Jie DI Yao-Min WEI Hai-Rui 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第4期653-658,共6页
We investigate the realization of 2-qutrit logic gate in a bipartite 3-level system with qusi-Ising interaction. On the basis of Caftan decomposition of matrices, the unitary matrices of 2-qutrit are factorized into p... We investigate the realization of 2-qutrit logic gate in a bipartite 3-level system with qusi-Ising interaction. On the basis of Caftan decomposition of matrices, the unitary matrices of 2-qutrit are factorized into products of a series of realizable matrices. It is equivalent to exerting a certain control field on the system, and the control goal is usually gained by a sequence of control pulses. The general discussion on the realization of 2-qutrit logic gate is made first, and then the realization of the ternary SWAP gate and the ternary √SWAP gate are discussed specifically, and the sequences of control pulses and drift processes implementing these gates are given. 展开更多
关键词 Caftan decomposition 2-qutrit system ternary SWAP gate ternary √SWAP gate
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Quantum Logic Networks for Probabilistic Teleportation of an Arbitrary Three-Particle State 被引量:1
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作者 QIAN Xue-Mir FANG Jian-Xing ZHU Shi-Qun XI Yong-Jun 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第4X期611-614,共4页
The scheme for probabilistic teleportation of an arbitrary three-particle state is proposed. By using single qubit gate and three two-qubit gates, efficient quantum logic networks for probabilistic teleportation of an... The scheme for probabilistic teleportation of an arbitrary three-particle state is proposed. By using single qubit gate and three two-qubit gates, efficient quantum logic networks for probabilistic teleportation of an arbitrary three-particle state are constructed. 展开更多
关键词 probabilistic teleportation arbitrary three-particle state quantum logic networks
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Using Self-referencing Interlaced Submatrices to Determine the Number of Chemical Species in a Mixture
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作者 Miao Wang Wan-ping Wang Li-min Shao 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2018年第6期818-826,734,共10页
Determining the number of chemical species is the first step in analyses of a chemical or biological system. A novel method is proposed to address this issue by taking advantage of frequency differences between chemic... Determining the number of chemical species is the first step in analyses of a chemical or biological system. A novel method is proposed to address this issue by taking advantage of frequency differences between chemical information and noise. Two interlaced submatrices were obtained by downsampling an original data spectra matrix in an interlacing manner. The two interlaced submatrices contained similar chemical information but different noise levels. The number of relevant chemical species was determined through pairwise comparisons of principal components obtained by principal component analysis of the two interlaced submatrices. The proposed method, referred to as SRISM, uses two self-referencing interlaced submatrices to make the determination. SRISM was able to selectively distinguish relevant chemical species from various types of interference factors such as signal overlapping, minor components and noise in simulated datasets. Its performance was further validated using experimental datasets that contained high-levels of instrument aberrations, signal overlapping and collinearity. SRISM was also applied to infrared spectral data obtained from atmospheric monitoring. It has great potential for overcoming various types of interference factor. This method is mathematically rigorous, computationally efficient, and readily automated. 展开更多
关键词 Number of chemical species Bilinear two-way data matrix Interlaced submatrix Principal component analysis
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Analytic Expression of Arbitrary Matrix Elements for Boson Exponential Quadratic Polynomial Operators
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作者 XU Xiu-Wei REN Ting-Qi LIU Shu-Yan MA Qiu-Ming LIU Sheng-Dian 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第1期41-44,共4页
Making use of the transformation relation among usual, normal, and antinormal ordering for the multimode boson exponential quadratic polynomial operators (BEQPO's)I we present the analytic expression of arbitrary m... Making use of the transformation relation among usual, normal, and antinormal ordering for the multimode boson exponential quadratic polynomial operators (BEQPO's)I we present the analytic expression of arbitrary matrix elements for BEQPO's. As a preliminary application, we obtain the exact expressions of partition function about the boson quadratic polynomial system, matrix elements in particle-number, coordinate, and momentum representation, and P representation for the BEQPO's. 展开更多
关键词 Boson exponential quadratic polynomial operator matrix element P representation partition function of Boson quadratic polynomial system
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A SUBARRAY-SYNTHESIS BASED 2D DOA ESTIMATION METHOD
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作者 Xu Wenlong Jiang Wei Li Zengfu Shang Yong Xiang Haige 《Journal of Electronics(China)》 2006年第5期645-649,共5页
In some satellite communications, we need to perform Direction Of Arrival (DOA) angle estima- tion under the restriction that the number of receivers is less than that of the array elements in an array antenna. To sol... In some satellite communications, we need to perform Direction Of Arrival (DOA) angle estima- tion under the restriction that the number of receivers is less than that of the array elements in an array antenna. To solve the conundrum, a method named subarray-synthesis-based Two-Dimensional DOA (2D DOA) angle estimation is proposed. In the method, firstly, the array antenna is divided into a series of subarray antennas based on the total number of receivers; secondly, the subarray antennas’ output covariance matrices are esti- mated; thirdly, an equivalent covariance matrix is synthesized based on the subarray output covariance matri- ces; then 2D DOA estimation is performed. Monte Carlo simulations showed that the estimation method is ef- fective. 展开更多
关键词 Spatial signal processing Direction Of Arrival (DOA) estimation Eigenspace decomposition Time Division Multiplex (TDM) Subarray synthesis
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Entropy of Partitions on Quantum Logic
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作者 YUANHe-Jun 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第3期437-439,共3页
Partition and entropy of partitions in quantum logic are introduced and their properties are investigated.The results are generalized to the general case of T-norm and T-conorm.
关键词 quantum logic entropy of partitions STATE
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Quantum Mechanical Image of Matrices' LDU Decomposition
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作者 范洪义 袁少杰 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第6期1024-1026,共3页
For classical transformation (q1,q2) → (Aq1 + Bq2, Cq1 + Dq2), where AD - CB ≠ 1, we find its quantum mechanical image by using LDU decomposition of the matrix (A B C D ). The explicit operators L, D, and U ... For classical transformation (q1,q2) → (Aq1 + Bq2, Cq1 + Dq2), where AD - CB ≠ 1, we find its quantum mechanical image by using LDU decomposition of the matrix (A B C D ). The explicit operators L, D, and U axe derived and their physical meaning is revealed, this also provides a new way for disentangling some exponential operators. 展开更多
关键词 quantum unitary operator LDU decomposition of matrices the IWOP technique
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Two-Component Description for Relativistic Fermions
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作者 CHEN Yu-Qi SANG Wen-Long YANG Lan-Fei 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第6期1095-1100,共6页
We propose a two-component form to describe massive relativistic fermions in gauge theories. Relations between the Green's functions in this form and those in the conventional four-component form are derived. It is s... We propose a two-component form to describe massive relativistic fermions in gauge theories. Relations between the Green's functions in this form and those in the conventional four-component form are derived. It is shown that the S-matrix elements in both forms are exactly the same. The description of the fermion in the new form simplifies significantly the γ-matrix algebra in the four-component form. In particular, in perturbative calculations the propagator of the fermion is a scalar function. As examples, we use this form to reproduce the relativistic spectrum of hydrodron atom, the S-matrix of e+e-→μ+μ- and QED one-loop vacuum polarization of photon. 展开更多
关键词 FERMIONS two-component description Dirac equation
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Survey of molecular profiling during human colon cancer development and progression by immunohistochemical staining on tissue microarray 被引量:12
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作者 Wei-Chang Chen Mao-Song Lin +4 位作者 Bao-Feng Zhang Jing Fang Qiong Zhou Ying Hu Heng-Jun Gao 《World Journal of Gastroenterology》 SCIE CAS CSCD 2007年第5期699-708,共10页
AIM: To explore the molecular events taking place during human colon cancer development and progression through high-throughput tissue microarray analysis. METHODS: We constructed two separate tissue microarrays con... AIM: To explore the molecular events taking place during human colon cancer development and progression through high-throughput tissue microarray analysis. METHODS: We constructed two separate tissue microarrays containing 1.0 mm or 1.5 mm cylindrical samples acquired from 112 formalin-fixed and paraffinembedded blocks, including carcinomas (n = 85), adenomatous polyps (n = 18), as well as normal paracancerous colon tissues (n = 9). Immunohistochemical staining was applied to the analysis of the consecutive tissue microarray sections with antibodies for 11 different proteins, including p53, p21, bcl-2, bax, cyclin D1, PTEN, p-Aktl, β-catenin, c-myc, nm23-h1 and Cox-2. RESULTS: The protein expressions of p53, bcl-2, bax, cyclin D1, β-catenin, c-myc, Cox-2 and nm23-h1 varied significantly among tissues from cancer, adenomatous polyps and normal colon mucosa (P = 0.003, P = 0.001, P = 0.000, P = 0.000, P = 0.034, P = 0.003, P = 0.002, and P = 0.007, respectively). Chi-square analysis showed that the statistically significant variables were p53, p21, bax, β-catenin, c-myc, PTEN, p-Aktl, Cox-2 and nm23-h1 for histological grade (P = 0.005, P = 0.013, P = 0.044, P = 0.000, P = 0.000, P = 0.029, P = 0.000, P = 0.008, and P = 0.000, respectively), β-catenin, comyc and p-Akt1 for lymph node metastasis (P = 0.011, P =0.005, and P = 0.032, respectively), β-catenin, c-myc, Cox-2 and nm23-h1 for distance metastasis (P = 0.020, P = 0.000, P = 0.026, and P = 0.008, respectively), and cyclin D1, β-catenin, c-myc, Cox-2 and nm23h1 for clinical stages (P = 0.038, P = 0.008, P = 0.000, P = 0.016, and P = 0.014, respectively). CONCLUSION: Tissue microarray immunohistochemical staining enables high-throughput analysis of genetic alterations contributing to human colon cancer development and progression. Our results implicate the potential roles of p53, cyclin D1, bcl-2, bax, Cox-2, β-catenin and c-myc in development of human colon cancer and that of bcl-2, nm23-h1, PTEN and p-Akt1 in progression of human colon cancer. 展开更多
关键词 Colon cancer IMMUNOHISTOCHEMISTRY Tissuemicroarray
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Density Matrix for Mesoscopic Distributed Parameter Circuits
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作者 JIYing-Hua WANGQi LUOHai-Mei LEIMin-Sheng 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第3期547-550,共4页
Under the Born-von-Karmann periodic boundary condition, we propose a quantization scheme for non-dissipative distributed parameter circuits (i.e. a uniform periodic transmission line). We find the unitary operator for... Under the Born-von-Karmann periodic boundary condition, we propose a quantization scheme for non-dissipative distributed parameter circuits (i.e. a uniform periodic transmission line). We find the unitary operator for diagonalizing the Hamiltonian of the uniform periodic transmission line. The unitary operator is expressed in a coordinate representation that brings convenience to deriving the density matrix rho(q,q',beta). The quantum fluctuations of charge and current at a definite temperature have been studied. It is shown that quantum fluctuations of distributed parameter circuits, which also have distributed properties, are related to both the circuit parameters and the positions and the mode of signals and temperature T. The higher the temperature is, the stronger quantum noise the circuit exhibits. 展开更多
关键词 mesoscopic distributed parameter circuits density matrix quantum fluctuations
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Double Symplectic Eigenfunction Expansion Method of Free Vibration of Rectangular Thin Plates 被引量:7
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作者 WANG Hua Alatancang HUANG Jun-Jie 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第12期1087-1092,共6页
The free vibration problem of rectangular thin plates is rewritten as a new upper triangular matrix differential system. For the associated operator matrix, we find that the two diagonal block operators are Hamiltonia... The free vibration problem of rectangular thin plates is rewritten as a new upper triangular matrix differential system. For the associated operator matrix, we find that the two diagonal block operators are Hamiltonian. Moreover, the existence and completeness of normed symplectic orthogonal eigenfunction systems of these two block operators are demonstrated. Based on the completeness, the general solution of the free vibration of rectangular thin plates is given by double symplectie eigenfunction expansion method. 展开更多
关键词 free vibration of rectangular thin plate double symplectic eigenfunction expansion method upper triangular matrix differential system general solution
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Comparative analysis of chemical components between barks and leaves of Eucommia ulmoides Oliver 被引量:10
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作者 周菊峰 张泰铭 +1 位作者 陈望爱 梁逸曾 《Journal of Central South University》 SCIE EI CAS 2009年第3期371-379,共9页
The chemical components of the essential oils in the barks and leaves of Eucommia ulmoides Oliver were analyzed and compared by chromatograms and mass spectra technique, heuristic evolving latent projections (HELP), a... The chemical components of the essential oils in the barks and leaves of Eucommia ulmoides Oliver were analyzed and compared by chromatograms and mass spectra technique, heuristic evolving latent projections (HELP), alternative moving window factor analysis (AMWFA) algorithms and normalization method based on the peak areas; the flavones in the barks and leaves of Eucommia ulmoides Oliver were separated on an ODS column by gradient elution carried out with the flow phase consisting of water, methanol and phosphoric acid (0.1%), and their contents were quantitatively determined by standard curve method and diode array detection (DAD) at 362 nm. The results show that 68 and 73 compounds respectively from essential oils of the barks and leaves of Eucommia ulmoides Oliver are identified, and there are 33 mutual compounds among 108 compounds determined. The total contents of these volatile components of the two samples possess 92.9% and 97.75% of the gross of the relevant essential oils, respectively; the contents of the rutin, quercetin and kaempferol in the barks and leaves of Eucommia ulmoides Oliver are 0.016 9, 0.003 6, 0.002 1 and 0.064 4, 0.030 2, 0.010 0 mg/g, respectively, and the determination recoveries are 95.2%-106.2%. The comparative analysis shows that for the barks and leaves of Eucommia ulmoides Oliver, there are significant differences in their components of the relevant essential oils and flavones. 展开更多
关键词 couple chromatography chemometric algorithm comparative analysis essential oil FLAVONE Eucommia ulmoides Oliver
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Notes on Quantitative Structure-Properties Relationships (QSPR) Part Four: Quantum Multimolecular Polyhedra, Collective Vectors, Quantum Similarity, and Quantum QSPR Fundamental Equation
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作者 Ramon Carbo-Dorca Silvia Gonzalez 《Management Studies》 2016年第1期33-47,共15页
The nature and origin of a fundamental quantum QSPR (QQSPR) equation are discussed. In principle, as any molecular structure can be associated to quantum mechanical density functions (DF), a molecular set can be r... The nature and origin of a fundamental quantum QSPR (QQSPR) equation are discussed. In principle, as any molecular structure can be associated to quantum mechanical density functions (DF), a molecular set can be reconstructed as a quantum multimolecular polyhedron (QMP), whose vertices are formed by each molecular DF. According to QQSPR theory, complicated kinds of molecular properties, like biological activity or toxicity, of molecular sets can be calculated via the quantum expectation value of an approximate Hermitian operator, which can be evaluated with the geometrical information contained in the attached QMP via quantum similarity matrices. Practical ways of solving the QQSPR problem from the point of view of QMP geometrical structure are provided. Such a development results into a powerful algorithm, which can be implemented within molecular design as an alternative to the current classical QSPR procedures. 展开更多
关键词 quantum similarity quantum multimolecular polyhedra (QMP) quantum QSPR (QQSPR) QQSPR fundamental equation QMP statistical-like collective functions QMP condensed collective indices classical QSPR-QSAR
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