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Truncated Gauss-Newton full-waveform inversion of pure quasi-P waves in vertical transverse isotropic media

Petroleum Science 2024年第5期21卷 3102-3124页

作者： zhi-Ming Ren lei Wang Qian-Zong Bao College of Geological Engineering and Geomatics Chang'an UniversityXi'an710064ShaanxiChina National Engineering Research Center of Offshore Oil and Gas Exploration Beijing100028China

Full-waveform inversion(FWI) uses the full information of seismic data to obtain a quantitative estimation of subsurface physical parameters. Anisotropic FWI has the potential to recover high-resolution velocity and anisotropy parameter models, which are critical for imaging the long-offset and wideazimuth data. We develop an acoustic anisotropic FWI method based on a simplified pure quasi P-wave(qP-wave) equation, which can be solved efficiently and is beneficial for the subsequent *** the inverse Hessian operator to precondition the functional gradients helps to reduce the parameter tradeoff in the multi-parameter inversion. To balance the accuracy and efficiency, we extend the truncated Gauss-Newton(TGN) method into FWI of pure qP-waves in vertical transverse isotropic(VTI) media. The inversion is performed in a nested way: a linear inner loop and a nonlinear outer *** derive the formulation of Hessian-vector products for pure qP-waves in VTI media based on the Lagrange multiplier method and compute the model update by solving a Gauss-Newton linear system via a matrix-free conjugate gradient method. A suitable preconditioner and the Eisenstat and Walker stopping criterion for the inner iterations are used to accelerate the convergence and avoid prohibitive computational cost. We test the proposed FWI method on several synthetic data sets. Inversion results reveal that the pure acoustic VTI FWI exhibits greater accuracy than the conventional pseudoacoustic VTI FWI. Additionally, the TGN method proves effective in mitigating the parameter crosstalk and increasing the accuracy of anisotropy parameters.

关键词： Full waveform inversion Anisotropy Pure quasi-P wave Gauss-Newton Hessian

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A machine learning approach to query generation in plagiarism source retrieval

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Frontiers of Information Technology & Electronic Engineering 2017年第10期18卷 1556-1572页

作者： lei-lei KONG zhi-mao LU Hao-liang QI Zhong-yuan HAN College of Information and Communication Engineering Harbin Engineering University Harbin 150001 China School of Computer Science and Technology Heilongjiang Institute of Technology Harbin 150050 China State Key Laboratory of digital Publishing Technology Beijing 100871 China

Plagiarism source retrieval is the core task of plagiarism detection. It has become the standard for plagiarism detection to use the queries extracted from suspicious documents to retrieve the plagiarism sources. Generating queries from a suspicious document is one of the most important steps in plagiarism source retrieval. Heuristic-based query generation methods are widely used in the current research. Each heuristic-based method has its own advantages, and no one statistically outperforms the others on all suspicious document segments when generating queries for source retrieval. Further improvements on heuristic methods for source retrieval rely mainly on the experience of experts. This leads to difficulties in putting forward new heuristic methods that can overcome the shortcomings of the existing ones. This paper paves the way for a new statistical machine learning approach to select the best queries from the candidates. The statistical machine learning approach to query generation for source retrieval is formulated as a ranking framework. Specifically, it aims to achieve the optimal source retrieval performance for each suspicious document segment. The proposed method exploits learning to rank to generate queries from the candidates. To our knowledge, our work is the first research to apply machine learning methods to resolve the problem of query generation for source retrieval. To solve the essential problem of an absence of training data for learning to rank, the building of training samples for source retrieval is also conducted. We rigorously evaluate various aspects of the proposed method on the publicly available PAN source retrieval corpus. With respect to the established baselines, the experimental results show that applying our proposed query generation method based on machine learning yields statistically significant improvements over baselines in source retrieval effectiveness.

关键词： Plagiarism detection Source retrieval Query generation Machine learning Learning to rank

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The potential mechanism and clinical application value of remote ischemic conditioning in stroke

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Neural Regeneration Research 2025年第6期20卷 1613-1627页

作者： Yajun Zhu Xiaoguo Li Xingwei lei Liuyang Tang Daochen Wen Bo Zeng Xiaofeng Zhang Zichao Huang Zongduo Guo The First Affiliated Hospital of Chongqing Medical University ChongqingChina

Some studies have confirmed the neuroprotective effect of remote ischemic conditioning against stroke. Although numerous animal researches have shown that the neuroprotective effect of remote ischemic conditioning may be related to neuroinflammation, cellular immunity, apoptosis, and autophagy, the exact underlying molecular mechanisms are unclear. This review summarizes the current status of different types of remote ischemic conditioning methods in animal and clinical studies and analyzes their commonalities and differences in neuroprotective mechanisms and signaling pathways. Remote ischemic conditioning has emerged as a potential therapeutic approach for improving stroke-induced brain injury owing to its simplicity, non-invasiveness, safety, and patient tolerability. different forms of remote ischemic conditioning exhibit distinct intervention patterns, timing, and application range. Mechanistically, remote ischemic conditioning can exert neuroprotective effects by activating the Notch1/phosphatidylinositol 3-kinase/Akt signaling pathway, improving cerebral perfusion, suppressing neuroinflammation, inhibiting cell apoptosis, activating autophagy, and promoting neural regeneration. While remote ischemic conditioning has shown potential in improving stroke outcomes, its full clinical translation has not yet been achieved.

关键词： Akt apoptosis autophagy cerebral perfusion cerebral vascular stenosis clinical transformation hemorrhagic stroke ischemic stroke neuroinflammation neuroprotection Notch1 PI3K remote ischemic conditioning stroke

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Convergence and Performance Analysis of the Affine Projection Algorithm with direction Error

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Chinese Journal of Electronics 2017年第2期26卷 351-357页

作者： zhi Yongfeng SI lei SHI Fuqian DAI Dameng School of Automation Northwestern Polytechnical University School of Information and Engineering Wenzhou Medical University College of Physics and Electronic Information Engineering Wenzhou University

A new statistical analysis model is proposed to analyze the Affine pro jection algorithm with direction error(AP-DE).Four assumptions are made,which are based on the direction vector for the AP-DE *** these assumptions,deterministic recursive equations for the weight error and for the mean-square error are *** also analyze the steady-state behavior of the AP-DE *** results are provided to corroborate the analytical results.

关键词： Adaptive filter Affine projection algorithm with direction error(AP-DE) Statistical analysis

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Enhancement of the flux for polypropylene hollow fiber membrane in a submerged membrane-bioreactor by surface modification

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Journal of Environmental Sciences 2006年第6期18卷 1050-1055页

作者： YU Hai-yin lei Hao XU zhi-kang Key Laboratory of Macromolecule Synthesis and Functionalization of Ministry of Education of China Institute of Polymer Science Zhejiang University Hangzhou 310027 China School of Chemistry and Materials Science Anhui Normal University Wuhu 241000 China

To improve its limiting flux and antifouling characteristics in a submerged membrane-bioreactor （SMBR） for wastewater treatment, polypropylene hollow fiber microporous membrane （PPHFMM） was surface-modified by the plasma-induced immobilization of poly （N-vinyl-2-pyrrolidone）（PVP） and the plasma treatment with different gases respectively. Attenuated total reflection-Fourier transform infrared spectroscopy （FT-IR/ATR）, X-ray photoelectron spectroscopy （XPS） and field emission scanning electron microscope （FE-SEM） were used to characterize the structural and morphological changes on the membrane surface. Water contact angle was measured by the sessile drop method. It was found that the water contact angle was 128.8, 72.3, 62.7, 74.4, 79.1, 86.3, and 71.3° for the nascent, PVP-immobilized, air, 02, Ar, CO2 and H2O plasma treated PPHFMM, respectively. The SMBR was operated at fixed transmembrane pressure to determine the limiting flux for the PPHFMM before and after surface modification. Results showed that the limiting flux appeared to be 103, 159, 117, 133, 136, 121 and 152 L/（m^2· h） for the nascent, PVP-immobilized, air, O2, At, CO2 and H2O plasma treated PPHFMM, respectively. After continuous operation for about 50 h in the SMBR, the antifouling characteristics were improved to some extent.

关键词： surface modification polypropylene hollow fiber microporous membrane limiting flux submerged membrane-bioreactor antifouling characteristics

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A promising approach for quantifying focal stroke modeling and assessing stroke progression:optical resolution photoacoustic microscopy photothrombosis

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Neural Regeneration Research 2025年第7期20卷 2029-2037页

作者： Xiao Liang Xingping Quan Xiaorui Geng Yujing Huang Yonghua Zhao lei Xi Zhen Yuan Ping Wang Bin Liu Faculty of Health Sciences University of MacaoMacao Special Administrative RegionChina Center for Cognitive and Brain Sciences University of MacaoMacao Special Administrative RegionChina Department of Biomedical Engineering Southern University of Science and TechnologyShenzhenGuangdong ProvinceChina State Key Laboratory of Quality Research in Chinese Medicine Institute of Chinese Medical SciencesUniversity of MacaoTaipaMacao Special Administrative RegionChina Department of Emergency Zhujiang HospitalSouthern Medical UniversityGuangzhouGuangdong ProvinceChina

To investigate the mechanisms underlying the onset and progression of ischemic stroke,some methods have been proposed that can simultaneously monitor and create embolisms in the animal cerebral ***,these methods often require complex systems and the effect of age on cerebral embolism has not been adequately studied,although ischemic stroke is strongly *** this study,we propose an optical-resolution photoacoustic microscopy-based visualized photothrombosis methodology to create and monitor ischemic stroke in mice simultaneously using a 532 nm pulsed *** observed the molding process in mice of different ages and presented age-dependent vascular embolism ***,we integrated optical coherence tomography angiography to investigate age-associated trends in cerebrovascular variability following a *** imaging data and quantitative analyses underscore the differential cerebrovascular responses to stroke in mice of different ages,thereby highlighting the technique's potential for evaluating cerebrovascular health and unraveling age-related mechanisms involved in ischemic strokes.

关键词： age-dependent cerebral cortex ischemic stroke mouse model optical coherence tomography angiography photoacoustic microscopy photothrombosis vascular imaging

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Inhibiting SHP2 reduces glycolysis, promotes microglial M1 polarization, and alleviates secondary inflammation following spinal cord injury in a mouse model

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Neural Regeneration Research 2025年第3期20卷 858-872页

作者： Xintian ding Chun Chen Heng Zhao Bin Dai lei Ye Tao Song Shuai Huang Jia Wang Tao You Department of Orthopedics The First Affiliated Hospital of USTCDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiAnhui ProvinceChina Department of Orthopedics Provincial Hospital Affiliated to Anhui Medical UniversityHefeiAnhui ProvinceChina

Reducing the secondary inflammatory response, which is partly mediated by microglia, is a key focus in the treatment of spinal cord injury. Src homology 2-containing protein tyrosine phosphatase 2(SHP2), encoded by PTPN11, is widely expressed in the human body and plays a role in inflammation through various mechanisms. Therefore, SHP2 is considered a potential target for the treatment of inflammation-related diseases. However, its role in secondary inflammation after spinal cord injury remains unclear. In this study, SHP2 was found to be abundantly expressed in microglia at the site of spinal cord injury. Inhibition of SHP2 expression using siRNA and SHP2 inhibitors attenuated the microglial inflammatory response in an in vitro lipopolysaccharide-induced model of inflammation. Notably, after treatment with SHP2 inhibitors, mice with spinal cord injury exhibited significantly improved hind limb locomotor function and reduced residual urine volume in the bladder. Subsequent in vitro experiments showed that, in microglia stimulated with lipopolysaccharide, inhibiting SHP2 expression promoted M2 polarization and inhibited M1 polarization. Finally, a co-culture experiment was conducted to assess the effect of microglia treated with SHP2 inhibitors on neuronal cells. The results demonstrated that inflammatory factors produced by microglia promoted neuronal apoptosis, while inhibiting SHP2 expression mitigated these effects. Collectively, our findings suggest that SHP2 enhances secondary inflammation and neuronal damage subsequent to spinal cord injury by modulating microglial phenotype. Therefore, inhibiting SHP2 alleviates the inflammatory response in mice with spinal cord injury and promotes functional recovery postinjury.

关键词： apoptosis glycolysis inflammatory response microglia neurons polarization spinal cord injury Src homology 2-containing protein tyrosine phosphatase 2

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Revolution in thermoelectric cooling using PbSe thermoelectrics by grid plainification

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Science China Materials 2024年第5期67卷 1672-1673页

作者： Xiao-lei Shi Qingfeng Liu zhi-Gang Chen School of Chemistry and Physics ARC Research Hub in Zero-emission Power Generation for Carbon Neutralityand Centre for Materials ScienceQueensland University of TechnologyBrisbaneQueensland4000Australia State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical EngineeringNanjing Tech UniversityNanjing211816China

Thermoelectric materials and devices enable direct conversion between heat and electricity,holding potential applications in thermoelectric power generation,localized cooling,and electronic thermal management[1].Howev... 详细信息

关键词： enable thermoelectric constrained

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Facile synthesis of hierarchical Ni_(3)Se_(2) nanodendrite arrays for supercapacitors

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Journal of Materials Science & Technology 2020年第19期54卷 69-76页

作者： Licheng Zhao Ping Zhang Yanan Zhang zhi Zhang lei Yang zhi-Gang Chen School of Materials Science&Engineering Sichuan UniversityChengdu 610064China Center for Nanoscale Characterization&Devices(CNCD) School of Physics&Wuhan National Laboratory for Optoelectronics(WNLO)Huazhong University of Science and Technology(HUST)Wuhan 430074China Centre for Future Materials University of Southern QueenslandSpringfieldQueensland4300Australia

Rational design has been widely used to develop high-performance metal selenides-based electrode materials for *** this study,we develop a facile one-step solvothermal approach to synthesize binder-free Ni_(3)Se_(2) nanodendrite arrays grown on nickel foam as advanced positive electrodes for *** Ni_(3)Se_(2) nanodendrite arrays on nickel foam exhibit a specific capacitance of 1234 Fg^(-1)(3.70 F cm^(-2))at a current density of 1 Ag^(-1) and a great rate capability,which is benefited from the excellent electrical conductivity and unique hierarchical nano-dendritic ***,an asymmetric supercapacitor device was assembled using activated carbon as the negative electrode and the Ni_(3)Se_(2) nanodendrite arrays on nickel foam as the positive electrode,obtaining a high energy density of 22.3 W h kg^(-1) at a power density of 160.4 W kg^(-1).

关键词： Ni3Se2 Nanodendrite Binder-free Capacitance Supercapacitors

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6 Gbps 16QAM fully integrated receiver using optimized neutralization technique LNA in 90 nm CMOS

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Science China(Information Sciences) 2018年第6期61卷 262-264页

作者： di LI lei ZHANG Yan WANG Institute of Microelectronics Tsinghua University

Dear editor,The research of multi-Gb/s wireless communication applications in millimeter wave,especially in 60 GHz unlicensed band has become attractive in recent *** fully-integrated complimentary metal oxide semicon... 详细信息

关键词： LNA PLL Gbps 16QAM fully integrated receiver using optimized neutralization technique LNA in 90 nm CMOS QAM

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