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A general evaluation system for optimal selection performance of radar clutter model

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Journal of Systems Engineering and Electronics 2023年第6期34卷 1520-1525页

作者： YANG Wei zhang Liang YANG Liru zhang wenpeng SHEN Qinmu College of Electronic Science and Technology National University of Defense TechnologyChangsha 410073China

The optimal selection of radar clutter model is the premise of target detection,tracking,recognition,and cognitive waveform design in clutter *** characterization models are usually derived by mathematical simplification or empirical data ***,the lack of standard model labels is a challenge in the optimal selection *** solve this problem,a general three-level evaluation system for the model selection performance is proposed,including model selection accuracy index based on simulation data,fit goodness indexs based on the optimally selected model,and evaluation index based on the supporting performance to its *** three-level evaluation system can more comprehensively and accurately describe the selection performance of the radar clutter model in different ways,and can be popularized and applied to the evaluation of other similar characterization model selection.

关键词： radar clutter clutter characterization model model selection performance evaluation.

Comprehensive Characterization of Phospholipid Isomers in Human Platelets

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Journal of Analysis and Testing 2020年第3期4卷 210-216页

作者： wenpeng zhang Bing Shang Yu Xia MOE Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biological Department of ChemistryTsinghua UniversityBeijing 100084People’s Republic of China Department of Chemistry Purdue UniversityWest LafayetteIN 47907USA

Lipids play an important role in platelet integrity and ***,most of lipid molecular compositions in platelets still remain unknown,especially for *** this work,we characterized detailed structures of different classes of phospholipids in human *** a flow microreactor,the acetone Paternò-Büchi reaction was introduced for online derivatization of carbon-carbon double bond(C=C)of lipids right after separation by liquid chromatography(LC).Tandem mass spectrometry(MS/MS)methods were developed for multi-level structural identification of phospholipids,including head group,chain composition,and C=C locations in the fatty acyl/alkyl *** optimization of the workflow,a total of 110 molecular species of phospholipids were identified in the human platelet samples,including many C=C location *** lipid class level,phosphatidylserine was found more abundant in the platelet samples than that of the plasma samples;at isomer level,the relative ratio of C18:1(Δ9)vs C18:1(Δ11)also increased in platelet samples comparing with that of the plasma *** detailed structural information of phospholipids and their C=C isomers ratios would be useful for investigation of potential functions of human platelets potentially associated with phospholipid isomers.

关键词： Platelet Phospholipid Carbon-carbon double bond The Paternò-Büchi reaction

An interesting identity and asymptotic formula related to the Dedekind sums

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Science China Mathematics 2014年第3期57卷 659-663页

作者： XU ZheFeng zhang wenpeng Department of Mathematics Northwest University

We use the analytic methods and the properties of Gauss sums to study one kind mean value problems involving the classical Dedekind sums,and give an interesting identity and asymptotic formula for it.

关键词： Dedekind sums mean value analytic method identity asymptotic formula

Site-Specific Photochemical Reaction for Improved C=C Location Analysis of Unsaturated Lipids by Ultraviolet Photodissociation

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Research 2022年第2期2022卷 283-294页

作者： Hai-Fang Li Jing Zhao Wenbo Cao wenpeng zhang Yu Xia Zheng Ouyang State Key Laboratory of Precision Measurement Techmology and Insruments Department of Precison InstrumentTsinghua UniversityBejing 10084China MOE Key Laboratory of Booganic Phosphorus Chemistry&Chemical Biology.Department of Chemistry Tsinghua UniversityBeijing 100084China

Unraveling the complexity of the lipidome requires the development of novel approaches to facilitate structural identification and characterization of lipid species with isomer-level *** photodissociation tandem mass spectrometry(UVPD MS/MS)is a promising tool for structure determination of *** sensitivity of UVPD for lipid analysis however *** mainly due to weak absorption of UV photons bya C=***,a C=C site-specific derivatization,the Paterno-Bichi.(PB)reaction,was used to incorporate a chromophore to the C=C moiety in fatty acyls,leading to significantly improved UVPD eficiency and sensitivity for pinpointing C=C *** wavelength-dependent photodissociation of the PB products demonstrated 4-CF;-benzophenone as the best reagent for UVPD in terms of the efficiency of generating C=C diagnostic fragments and simplicity for C=C location *** demonstrated the efectiveness of this approach for the shotgun profiling of C=C location isomers in diferent lipid classes from complex lipid extraclis,highlighting its potential to advancing the identification of the C=C bond locations in unsaturated lipids.

关键词： dissociation isomers simplicity

New-corrected functions of X-ray powder diffraction

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Chinese Science Bulletin 2009年第21期54卷 3940-3946页

作者： zhang QingLi LIU wenpeng DING LiHua JIANG HaiHe YIN ShaoTang Crystal Laboratory Anhui Institute of Optics and Fine Mechanics Chinese Academy of Sciences Hefei 230031 China

X-ray powder diffraction is an indispensable technique to study material structure, phase transition and so on. It is necessary for high quality diffraction data to get high-precision diffraction angle. This work proposed four corrected functions of X-ray powder diffraction angle. Two methods, linearization method and modified Levenberg-Marquardt iteration method, are given to solve the function parameters, and the modified Levenberg-Marquardt method has fast convergent speed and stable solution. Two methods can give closed parameters, including those of Lu, Liu, and Chu functions and polynomial. New-corrected functions were used to fit the diffraction angle error of the tetragonal rutile poly- crystalline TiO2 mixed with Gd0.45Y2.55Sc2Ga3O12 as a standard sample, and the computation result indicates that these functions can characterize the diffraction error very well. In some cases, the new-corrected functions can describe the diffraction angle error better than the reported corrected functions. At the same time, the lattice parameter of Gd0.45Y2.55Sc2Ga3O12 was computed with two methods. When the corrected function parameters and lattice parameters were solved by the least square method, the interaction of the function parameters and lattice parameters would result in great error. However, when the X-ray diffraction angles were corrected by corrected functions using a standard sample, the authentic lattice parameters can be obtained by the least square fitting.

关键词： X射线衍射校正功能 Marquardt 晶格参数最小二乘拟合功能参数标准样品计算结果

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Journal of Systems Science & Complexity 2003年第1期16卷 13-18页

作者： zhang wenpeng Research Center for Basic Science Xi'an Jiaotony University Xi'an 710049

The main purpose of this paper is to study a problem related to Golomb’s conjectures, and give an interesting asymptotic formula.

关键词： Primitive roots golomb’s conjecture asymptotic formula.

A hybrid mean value related to the Dedekind sums and Kloosterman sums

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Science China Mathematics 2010年第9期53卷 2543-2550页

作者： zhang wenpeng & LIU YanNi Department of Mathematics,Northwest University,Xi’an 710127,China Department of Mathematics Northwest University Xi’an China

The main purpose of this paper is using the properties of character sum and the analytic method to study a hybrid mean value problem related to the Dedekind sums and Kloosterman sums,and give some interesting mean val... 详细信息

关键词： Dedekind sum Kloosterman sums Hybrid mean value asymptotic formula identity

Simultaneous determination of three curcuminoids in Curcuma longa *** high performance liquid chromatography coupled with electrochemical detection

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Journal of Pharmaceutical Analysis 2014年第5期4卷 325-330页

作者： Yuling Long wenpeng zhang Fang Wang Zilin Chen Key Laboratory of Combinatorial Biosynthesis and Drug Discovery Wuhan UniversityMinistry of Education Wuhan University School of Pharmaceutical Sciences

A novel method for analysis of three active components curcumin, demethoxycurcumin and bisdemethoxycurcumin in Curcuma longa L. was developed by HPLC coupled with electrochemical detection. Three curcuminoids were well separated on a C18 column and detected with high sensitivity. A mobile phase containing acetonitrile and 10 mM Na2HPO4-H3PO4 （pH 5.0）（50：50, v/v） was used. Good linearity was obtained in the range of 0.208-41.6, 0.197-39.4, and 0.227-114μM for curcumin, demethoxycurcumin and bisdemethoxycurcumin respectively. The limit of detection reached up to 10 ？ 8 M, which was lower than that by UV detection. The relative standard deviations （RSDs） ranged from 1.06%to 1.88%for intra-day precision and from 4.30%to 5.79%for inter-day precision, respectively. The proposed method has been applied in real herb sample and recoveries ranging from 86.3%to 111%were obtained.

关键词： Curcumin High performance liquidchromatography Electrochemical detec- tion Curcuma longa L.

On the Mean Value Formula of Dedekind Sums

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Acta Mathematica Sinica,English Series 1999年第2期15卷 245-254页

作者： Xiali He wenpeng zhang, Department of Mathematics, Northwest University, Xi’an 710069, P. R. China Department of Mathematics Northwest University Xi’an P. R. China

The main purpose of this paper is to use the mean value theorem of the Dirichlet L-function to study the distribution property of Dedekind sums, and to give a sharper mean value formula.

关键词： Dedekind sums Distribution of the mean value Asymptotic formula