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Extended ambiguity function for bistatic MIMO radar

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Journal of Systems Engineering and Electronics 2012年第2期23卷 195-200页

作者： Haowen chen yiping chen Zhaocheng Yang Xiang Li Institute of Space Electronic Information Technology School of Electronic Science and EngineeringNational University of Defense TechnologyChangsha 410073P.R.China

This paper derives the extended ambiguity function for a bistatic multiple-input multiple-output （MIMO） radar system, which includes the whole radar system parameters： geometric sensor configuration, waveforms, range, range rate, target scattering and noise characteristics. Recent research indicates the potential pa- rameter estimate performance of bistatic MIMO radars. And this ambiguity function can be used to analyze the parameter estimate performance for the relationship with the Cramer-Rao bounds of the estimated parameters. Finally, some examples are given to demonstrate the good parameter estimate performance of the bistatic MIMO radar, using the quasi-orthogonal waveforms based on Lorenz chaotic systems.

关键词： bistatic multiple-input multiple-output (MIMO) radar ambiguity function parameter estimate Cramer-Rao bound (CRB) quasi-orthogonal waveforms.

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浅析震源位置准确度及其影响因素

地球与行星物理论评（中英文） 2025年第2期56卷 182-192页

作者：张风雪李昱陈泆平中国地震局地球物理研究所北京100081

地震定位是地震学研究的基础,然而地震定位和地震学研究之间存在“供给”矛盾.不同研究对地震位置准确度级别的要求不尽相同,震源机制和壳幔结构研究要求震源位置的准确度为千米级别,工业生产活动和诱发地震研究要求震源位置的准确度为... 详细信息

地震定位是地震学研究的基础,然而地震定位和地震学研究之间存在“供给”矛盾.不同研究对地震位置准确度级别的要求不尽相同,震源机制和壳幔结构研究要求震源位置的准确度为千米级别,工业生产活动和诱发地震研究要求震源位置的准确度为百米级别.然而,地震监测台网给出的地震位置准确度仅为数千米.诸多地震定位方法从不同方面对地震定位过程进行优化和改进,但它们的侧重点不尽相同.总体而言,已有的定位方法对地震位置的准确度关注程度尚显不足.在大量的地震定位实践中,前人获得了用于优化地震位置准确度的若干经验法则,这些经验法则不但存在地区差异,而且还有一定的适用条件,经验法则仍需要被进一步地优化和修正.本文简要分析地震定位准确度的多方面影响因素,有针对性地开展研究,在地震定位算法和控制观测数据质量方面获得一定的研究进展;在地震定位耦合关系方面补充了定位速度模型、发震位置和发震时刻三者之间的制约关系;在地震定位流程方面提出了使用逐步消元定位的建议.

关键词：地震定位震源位置准确度网格搜索定位观测数据质量定位耦合关系

CRYSTALLOGRAPHIC HOMOGENIZATION FINITE ELEMENT METHOD AND ITS APPLICATION ON SIMULATION OF EVOLUTION OF PLASTIC DEFORMATION INDUCED TEXTURE

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Acta Mechanica Solida Sinica 2010年第1期23卷 36-48页

作者： yiping chen W.B. Lee E. Nakamachi Department of Mechanics Huazhong University of Science and Technology Wuhan 430074 China State Key Laboratory for Forming Simulation and Die and Mould Technology Huazhong University of Science and Technology Wuhan 430074 China Department of Industrial and Systems Engineering The Hong Kong Polytechnic University Hong Kong China Department of Mechanical Engineering Osaka Institute of Technology Osaka Japan

A crystallographic homogenization method is proposed and implemented to predict the evolution of plastic deformation induced texture and plastic anisotropy （earring） in the stamping of polycrystalline sheet metals. The microscopic inhomogeneity of crystal aggregate has been taken into account with the microstructure made up of a representative aggregate of single crystal grains. Multi-scale analysis is performed by coupling the microscopic crystal plasticity with the macroscopic continuum response through the present homogenization procedure. The macroscopic stress is defined as the volume average of the corresponding microscopic crystal aggregations, which simultaneously satisfies the equation of motion in both micro- and macro-states. The proposed numerical implementation is based on a finite element discretization of the macrocontinuum, which is locally coupled at each Gaussian point with a finite element discretization of the attached micro-structure. The solution strategy for the macro-continuum and the pointwiseattached micro-structure is implemented by the simultaneous employment of dynamic explicit FE formulation. The rate-dependent crystal plasticity model is used for the constitutive description of the constituent single crystal grains. It has been confirmed that Taylor＇s constant strain homogenization assumption yields an undue concentration of the preferred crystal orientation compared with the present homogenization in the prediction of texture evolution, with the latter having relaxed the constraints on the crystal grains. Two kinds of numerical examples are presented to demonstrate the capability of the developed code： 1） The texture evolution of three representative deformation modes, and 2） Plastic anisotropy （earring） prediction in the hemispherical cup deep drawing process of aluminum alloy A5052 with initial texture. By comparison of simulation results with those obtained employing direct crystal plasticity calculation adopting Taylor assumption,

关键词： homogenization crystal plasticity texture microstructure earring

An immunoassay based on lab-on-a-chip for simultaneous and sensitive detection of clenbuterol and ractopamine

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Chinese Chemical Letters 2020年第7期31卷 1835-1838页

作者： Qi Wang Jinqi Deng yiping chen Yunjing Luo Xingyu Jiang College of Life Science and Bioengineering Beijing University of TechnologyBeijing 100124China Beijing Engineering Research Center for BioNanotechnology and CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety CAS Center for Excellence in NanoscienceNational Center for NanoScience and TechnologyBeijing 100190China Department of Biomedical Engineering Southern University of Science and Technology.Shenzhen 518055China University of Chinese Academy of Sciences Beijing 100049China College of Food Science and Technology.Huazhong Agricultural University Wuhan 430070China

Both clenbuterol(CLB)and ractopamine(RAC)areβ-adrenergic *** long-term excessive intake,there will be adverse reactions such as headache,chest tightness,limb numbness,and serious *** detection of CLB and RAC in related samples is of great importance for human *** this work,we outline a microfluidics-based indirect competitive immunoassay(MICI)system that can sensitively detect residual CLB and RAC in pork,swine blood and swine *** rapid detection of multiple samples can be achieved in one chip,which greatly improves the detection *** method has good stability and reproducibility and the microfluidic chips are easy to *** linear ranges for CLB and RAC detection by MICI are 0.1-2.5 ng/mL and 0.1-5 ng/mL,and the limits of detection(LODs)are 0.094 ng/mL and 0.091 ng/mL,*** straightforward and portable immunoassay system provides a good platform for rapid detection of harmful substances in food samples.

关键词： Microfluidic chips Simultaneous detection Indirect competitive immunoassay Clenbuterol Ractopamine

Fractal Structure of the Core Loss Spectrum of Co-based Amorphous Soft Magnetic Alloy with Constant Permeability

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International Journal of Minerals,Metallurgy and Materials 1999年第1期13卷 54-56页

作者： yiping chen (Applied Science School, University of Science and Technology Beijing, Beijing 100083, China) Applied Science School University of Science and Technology Beijing Beijing 100083 China

In order to check the traditional core loss formula, the core loss spectrum P(f) of Co-based amorphous soft magnetic alloy with constant permeability has been studied. It is found that within a high frequency range from 10 kHz to 200 kHz and at Bm = 0. 1 T,the P(f) has the fractal structure P (f) = Po, and with the increasing of induced anisotropy energy Ku, the fractal dimension Dfrises, thus the total power loss at high frequency increases and the frequency characteristic of P(f) becomes worse.

关键词： amorphous soft magnetic alloy constant permeability core loss fractal

Process and Construction of Political Philosophy Studies in China Since the Founding of PRC

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学术界 2010年第11期 261-265页

作者： chen yiping Politics Department,Anhui University

Political Philosophy is the metatheory in the political theoretical *** analyzing the course research on Political Philosophy,the article tries to find out the way of building Marxist Political Philosophy in modern Ch... 详细信息

关键词： Process and Construction of Political Philosophy Studies in China Since the Founding of PRC

FGF8-mediated signaling regulates tooth developmental pace during odontogenesis

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Journal of Genetics and Genomics 2022年第1期49卷 40-53页

作者： chensheng Lin Ningsheng Ruan Linjun Li Yibin chen Xiaoxiao Hu yiping chen Xuefeng Hu Yanding Zhang Fujian Key Laboratory of Developmental and Neural Biology and Southern Center for Biomedical Research College of Life SciencesFujian Normal UniversityFuzhouFujian 350117China Department of Cell and Molecular Biology Tulane UniversityNew OrleansLA 70118USA

The developing human and mouse teeth constitute an ideal model system to study the regulatory mechanism underlying organ growth control since their teeth share highly conserved and well-characterized developmental processes, and their developmental tempo varies notably. In the current study, we manipulated heterogenous recombination between human and mouse dental tissues and demonstrated that the dental mesenchyme dominates the tooth developmental tempo and FGF8 could be a critical player during this developmental process. Forced activation of FGF8 signaling in the dental mesenchyme of mice promoted cell proliferation, prevented cell apoptosis via p38 and perhaps PI3 K-Akt intracellular signaling,and impelled the transition of the cell cycle from G1-to S-phase in the tooth germ, resulting in the slowdown of the tooth developmental pace. Our results provide compelling evidence that extrinsic signals can profoundly affect tooth developmental tempo, and the dental mesenchymal FGF8 could be a pivotal factor in controlling the developmental pace in a non-cell-autonomous manner during mammalian odontogenesis.

关键词： FGF8 Tooth Developmental pace Non-cell-autonomous

Dynamics of ecosystem carbon stocks during vegetation restoration on the Loess Plateau of China

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Journal of Arid Land 2016年第2期8卷 207-220页

作者： WANG Kaibo DENG Lei REN Zongping SHI Weiyu chen yiping SHANG-GUAN Zhouping State Key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy of Sciences State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Northwest A&F University State Key Laboratory Base of Eco-Hydraulic Engineering in Arid Area Xi'an University of Technology

In the last few decades, the Loess Plateau had experienced an extensive vegetation restoration to reduce soil erosion and to improve the degraded ecosystems. However, the dynamics of ecosystem carbon stocks with vegetation restoration in this region are poorly understood. This study examined the changes of carbon stocks in mineral soil （0-100 cm）, plant biomass and the ecosystem （plant and soil） following vegetation restoration with different models and ages. Our results indicated that cultivated land returned to native vegetation （natural restoration） or artificial forest increased ecosystem carbon sequestration. Tree plantation sequestered more carbon than natural vegetation succession over decades scale due to the rapid increase in biomass carbon pool. Restoration ages had different effects on the dynamics of biomass and soil carbon stocks. Biomass carbon stocks increased with vegetation restoration age, while the dynamics of soil carbon stocks were affected by sampling depth. Ecosystem carbon stocks consistently increased after tree plantation regardless of the soil depth; but an initial decrease and then increase trend was observed in natural restoration chronosequences with the soil sampling depth of 0-100 cm. Moreover, there was a time lag of about 15-30 years between biomass production and soil carbon sequestration in 0-100 cm, which indicated a long-term effect of vegetation restoration on deeper soil carbon sequestration.

关键词： ages carbon stocks natural vegetation restoration tree plantation Loess Plateau

Management of re‐established artificial grasslands via grazing or fencing: Effects on plant and soil properties

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Grassland Research 2023年第1期2卷 69-83页

作者： Jing Cao yiping chen Yao Jiang Jingshu chen Junhua Wu State Key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy of SciencesXi'anChina University of Chinese Academy of Sciences BeijingChina Xi'an Institute for Innovative Earth Environment Research Xi'anChina

Background:Revegetation is widely used in degraded grassland ***,the responses of grassland plant and soil properties to fencing(FC)and grazing(GZ)remain poorly understood,especially the vegetation–soil coupling coordination(C_(d))*** study explored single and interactive responses of vegetation and soil properties under FC and GZ after ***:A field experiment with FC and GZ treatments was conducted in Loess Plateau reconstructed grassland,with degraded grassland as the control(CK).Plant and soil properties and C_(d) were analyzed using the analytic hierarchy process(AHP)and principal component analysis(PCA).Results:The order of soil comprehensive evaluation(SCE)was GZ>FC>CK,while that of vegetation comprehensive evaluation(VCE)was FC>GZ>*** C_(d) of CK was 0.39(mild imbalance),while the values of FC and GZ were 0.57 and 0.54,respectively(little coordination).The VCE/SCE of FC was 1.48(soil lag type),and the values of GZ and CK were 0.69 and 0.35,respectively(vegetation lag and vegetation loss type,respectively).Conclusions:Both GZ and FC improved C_(d) and facilitated ***,degraded grasslands should be restored via moderate grazing for sustainable ecological and economic development.

关键词： degraded artificial grassland grazing and fencing revegetation vegetation-soil coupling coordination