检索结果-南通市图书馆

A Target Recognition Approach to Projecting HRR Profiles onto Subspace

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2003年第1期14卷 36-40页

作者： Pei Bingnan & Bao ZhengKey Lab. of Radar Signal Processing, Xidian university, Xi’an 710071, P. R. China Dept. of Electronic Engineering, zhengzhou university, zhengzhou 450052, P.R. China Key Lab. of adar Signal Processing Xidian University. Xi'an 710071 P. R. China Dept. of Electronic Engineering Zhengzhou University Zhengzhou 450052 P. R. China

Abstract: A array of the azimuthally averaged range-profile vectors and the inter-class and intra-class divergence matrixesare constructed iwth many frames of the high resolution range profiles which result from radar echoes of airplanes. Takingthe methods of whitening transformation and SVD produces a system of subspace vectors for target recognition. Where-upon, a template library for target recognition is built by the projection of a class-mean vector made from the radar dataonto the subspace for recognition. By Euclidean distance, a comparison is made between the above projection and eachtemplate in the library, to decide which class the target belongs to. Finally, simulations with the experimental radar dataarte given to show that the proposed method is robust to variation in azimuth and immune to additive Gaussian noisewhen SNR≥5dB.

关键词： Automatic target recognition High range resolution profile Distance classifier SVD Computer simulation

Catalytic Hydrogenation of Diacetyl Monoxime to Tetramethylpyrazine with the Soluble Transition Metal Catalysts

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1999年第8期10卷 701-704页

作者： Xiang Yu WANG Xiao Ming ZHENG Zhao Yin HOU (Institute of Catalysis, Zhejiang university (Xixi campus), Hangzhou 310028) (Department of Chemistry, zhengzhou university, zhengzhou 450052) Zhejiang Univ Inst Catalysis Hangzhou 310028 Peoples R China zhengzhou Univ Dept Chem Zhengzhou 450052 Peoples R China

Catalytic hydrogenation of diacetyl monoxime to tetramethylpyrazine, by the homogeneous catalysts generated in situ from some transition metal chlorides with triphenylphosphine in ethanol under H-2 pressure of 0.6 similar to 4.6 MPa at 100 similar to 150 degrees C, has been studied. The optimum H-2 partial pressure was observed at about 1.3 MPa. The maximum conversion of diacetyl monoxime and yield of tetramethylpyrazine were 97% and 90%, respectively.

关键词： diacetyl monoxime catalytic hydrogenation tetramethylpyrazine

Synthesis and Crystal Structure of Complex of Sodium Perrhenate with Tetraethyl p-tert-Butylcalix[4]arene Tetraacetate

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1998年第11期9卷 0-0页

作者： Zhi Xian ZHOU Yan Jun XING Kui LU Yang Jie WU (Department of Chemistry, zhengzhou university, zhengzhou 450052) zhengzhou Univ Dept Chem Zhengzhou 450052 Peoples R China

The complex of sodium perrhenate with ester derivative of calix[4]arene having the stoichiometric formula [NaL]Reo4.H2O, was prepared. The X-ray structure analysis revealed that the sodium ion is coordinated to four ether and four carbonyl oxygen atoms giving a coordination number of eight with a tetragonal antiprism configUration. The complex cation [NaL]+ and anion ReO4 are linked by electrostatic attraction.

关键词： Calix arene sodium perrhenate, crystal structure

INITIAL VALUE PROBLEM FOR A CLASS OF NONLINEAR PARABOLIC SYSTEM OF FOURTH-ORDER

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 1991年第4期11卷 393-400页

作者：陈国旺 Institute of Mathematics Zhengzhou University Zhengzhou China

In this paper, the periodic boundary problem and the initial value problem for the nonlinear system of parabolic type u1=-A（x, t）ux4+B（x, t）ux2+（g（u））x2+（grad h（u））x+f（u）are studied, where u（x, t）=(u1（x, t）.…, uJ（x, t） is a J-dimensional unknown vector valued function, f（u） and g（u） are the J-dimensional vector valued function of u（x, t）, h（u） is a scalar function of u, A（x, t） and B（x, t） are J×J matrices of functions. The existent, uniqueness and regularities of the generalized global solution and classical global solution of the problems are proved. When J=1, h（u）=0, g（u）=au3, A=a1, B=a2, where a1, a2 a are constants, the system is a generalized diffusion model equation in population problem.

关键词： valued uniqueness parabolic scalar matrices constants CLASS formulas uniformly 八布

THE NP-HARDNESS OF THE SINGLE MACHINE COMMON DUE DATE WEIGHTED TARDINESS PROBLEM

在线全文

学校读者我要写书评

暂无评论

Systems Science and Mathematical Sciences 1992年第4期5卷 328-333页

作者： YUAN Jinjiang (Department of Mathematics,zhengzhou university,zhengzhou 450052,China)

In this paper we prove that the single machine common due dateweighted tardiness problem is NP-hard.

关键词： Due date tardiness NP-complete

Synthesis of Mn(Ⅲ) Complexes of New "Tailed" Porphyrins and Their Application as Carriers for PVC Membrane SCN-Anion-Selective Electrode

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1997年第11期8卷 997-999,0页

作者： Zhi Xian ZHOU Tie Sheng LI Yu Zhong WANG Yang Jie WU (Department of Chemistry, zhengzhou university, zhengzhou 450052) Department of Chemistry Zhengzhou University Zhengzhou 450052 China

Three new 'tailed' porphyrins and their corresponding Mn(Ⅲ) metalloporphyrins were synthesized and characterized. The potentiometric response characteristics of the PVC membrane electrode based on the Mn(Ⅲ) comple... 详细信息

关键词： SCN PVC Complexes of New Porphyrins and Their Application as Carriers for PVC Membrane SCN-Anion-Selective Electrode Tailed

A Characterization of the Optimal p-sum Labellingsof Unit Interval Graphs

在线全文

学校读者我要写书评

暂无评论

运筹学学报 1998年第3期2卷 1-5页

作者： JINJIANG YUAN(Department of Mathematics, zhengzhou university, zhengzhou, 450052) 郑州大学数学系河南郑州

A labelling π of a graph G is regular if for every edge uv ∈ E(G), say π(u) < π(v),V(u,v) = {x ∈ V(G) | π(u) π(x) π(v)} is a clique of G. We show in this paper that, for every positive real number p, a labelli... 详细信息

关键词： Regular labelling Optimal p-sum labelling unit interval graph

On the Construction of Regular Orthocryptogroups

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2002年第3期18卷 517-530页

作者： Xiang Zhi KONG Department of Mathematics, zhengzhou university. zhengzhou 450052, P. R. China Department of Mathematics, Qufu Normal university, Qufu 273165. P. R. China Department of Mathematics Zhengzhou University Zhengzhou P. R. China Department of Mathematics Qufu Normal University Qufu P. R. China

The aim of this paper is to study regular orthocryptogroups. After obtaining some charac- terizations of such semigroups, we establish the construction theorem of regular orthocryptogroups. As an application, we give the construction theorem of right quasi-normal orthocryptogroups and study homomorphisms between two regular orthocryptogroups.

关键词： Completely regular semigroup Regular band Orthodox Homomorphism Natural partial order

Determination　of　UV　Spectra　and　HMO　Approximate　Treatment　of　Benzocrown　Ethers

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 1996年第4期15卷 323-326页

作者： Yuan Hu-Shan Xu Shun Wang Guo-Ying(Department of Chemistry, zhengzhou university, zhengzhou, Henan, 450052) Ma Fu-Qin Liu Yu-Hua(Analysis Center, zhengzhou university, zhengzhou, Henan, 450052) Department of Chemistry Zhengzhou University Zhengzhou Henan 450052 Analysis Center Zhengzhou University Zhengzhou Henan 450052

The UV spectra of benzo-15-crown-5 and its four 4'-substituted derivatives were determined in fourteen solvents, and the energies ofπ-molecular orbitals were calculated by Huchel molecular orbital(HMO) method. With the results of calculation and determination, the linear-dependence of the π_(HOMO)-π_1 electron transition energy (△E1) with their UV maximum absorption wave number(v_(max1)) can be treated. It is found that there is a satisfactory linear relation. The calculation results could also be applied to explain an influence of substituent on the shifts of the UV absorption peaks of benzocrown ethers.

关键词： UV spectrum HMO benzocrown ether