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Bahadur Representation of Nonparametric M-Estimators for Spatial Processes

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Acta Mathematica Sinica,English Series 2008年第11期24卷 1871-1882页

作者： jia chen De Gui li li Xin ZHANG Department of Mathematics Zhejiang University Hangzhou 310027 P. R. China

Under some mild conditions, we establish a strong Bahadur representation of a general class of nonparametric local linear M-estimators for mixing processes on a random field. If the socalled optimal bandwidth hn = O（｜n｜^-1/5）, n ∈ Z^d, is chosen, then the remainder rates in the Bahadur representation for the local M-estimators of the regression function and its derivative are of order O（｜n｜^-4/5 log ｜n｜）. Moreover, we derive some asymptotic properties for the nonparametric local linear M-estimators as applications of our result.

关键词： Bahadur representation local linear M-estimator spatial processes strongly mixing

Characterization of Bacterial Community Structure and Diversity in Rhizosphere Soils of Three Plants in Rapidly Changing Salt Marshes Using 16S rDNA

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Pedosphere 2007年第5期17卷 545-556页

作者： WANG Meng chen jia-Kuan li Bo Coastal Ecosystems Research Station of Yangtze River Estuary Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering Institute of Biodiversity Science Fudan University 220 Handan Road Shanghai 200433 （China）.

The structure and diversity of the bacterial communities in rhizosphere soils of native Phragmites australis and Scirpus rnariqueter and alien Spartina alterniflora in the Yangtze River Estuary were investigated by constructing 16S ribosomal DNA （rDNA） clone libraries. The bacterial diversity was quantified by placing the clones into operational taxonomic unit （OTU） groups at the level of sequence similarity of 〉 97%. Phylogenetic analysis of the resulting 398 clone sequences indicated a high diversity of bacteria in the rhizosphere soils of these plants. The members of Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, and Deltaproteobacteria of the phylum Proteobacteria were the most abundant in rhizobacteria. Chao 1 nonpaxametric diversity estimator coupled with the reciprocal of Simpson＇s index （l/D） was applied to sequence data obtained from each library to evaluate total sequence diversity and quantitatively compare the level of dominance. The results showed that Phragmites, Scirpus, and Spartina rhizosphere soils contained 200, 668, and 382 OTUs, respectively. The bacterial communities in the Spartina and Phragraites rhizosphere soils displayed species dominance revealed by 1/D, whereas the bacterial community in Scirpus rhizosphere soil had uniform distributions of species abundance. Overall, analysis of 16S rDNA clone libraries from the rhizosphere soils indicates that the changes in bacterial composition may occur concomitantly with the shift of species composition in plant communities.

关键词： 16S rDNA bacterial diversity plant succession rhizosphere salt marshes

Solar cycle prediction using a long short-term memory deep learning model

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Research in Astronomy and Astrophysics 2021年第1期21卷 119-126页

作者： Qi-Jie Wang jia-chen li liang-Qi Guo School of Geosciences and Info-Physics Central South UniversityChangsha 410083China

In this paper,we propose a long short-term memory(LSTM)deep learning model to deal with the smoothed monthly sunspot number(SSN),aiming to address the problem whereby the prediction results of the existing sunspot prediction methods are not uniform and have large *** method optimizes the number of hidden nodes and batch sizes of the LSTM network structures to 19 and 20,*** best length of time series and the value of the timesteps were then determined for the network training,and one-step and multi-step predictions for Cycle 22 to Cycle 24 were made using the well-established *** results showed that the maximum root-mean-square error(RMSE)of the one-step prediction model was6.12 and the minimum was only *** maximum amplitude prediction error of the multi-step prediction was 17.2%and the minimum was only 3.0%.Finally,the next solar cycles(Cycle 25)peak amplitude was predicted to occur around 2023,with a peak value of about *** accuracy of this prediction method is better than that of the other commonly used methods,and the method has high applicability.

关键词： Sun:solar activity Sun:sunspot number techniques:deep learning techniques:long short-term memory

3D Object Tracking with Adaptively Weighted Local Bundles

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Journal of Computer Science & Technology 2021年第3期36卷 555-571页

作者： jia-chen li Fan Zhong Song-Hua Xu Xue-Ying Qin School of Software Shandong UniversityJinan 250101China School of Computer Science and Technology Shandong UniversityQingdao 266237China College of Engineering and Computing University of South CarolinaColumbia 29208U.S.A.

The 3D object tracking from a monocular RGB image is a challenging *** popular color and edgebased methods have been well studied,they are only applicable to certain cases and new solutions to the challenges in real environment must be *** this paper,we propose a robust 3D object tracking method with adaptively weighted local bundles called AWLB tracker to handle more complicated *** bundle represents a local region containing a set of local *** alleviate the negative effect of the features in low-confidence regions,the bundles are adaptively weighted using a spatially-variant weighting function based on the confidence values of the involved energy ***,in each frame,the weights of the energy items in each bundle are adapted to different situations and different regions of the same *** show that the proposed method can improve the overall accuracy in challenging *** then verify the effectiveness of the proposed confidence-based adaptive weighting method using ablation studies and show that the proposed method overperforms the existing single-feature methods and multi-feature methods without adaptive weighting.

关键词： 3D tracking local bundle feature fusion confidence map

Spatial electron-spin splitting in single-layered semiconductor microstructure modulated by Dresselhaus spin-orbit coupling

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Chinese Physics B 2024年第11期33卷 457-461页

作者： jia-li chen Sai-Yan chen li Wen Xue-li Cao Mao-Wang Lu College of Physics and Electronic Information Engineering Guilin University of TechnologyGuilin 541004China

Combining theory and computation,we explore the Goos–H¨anchen(GH)effect for electrons in a single-layered semiconductor microstructure(SLSM)modulated by Dresselhaus spin–orbit coupling(SOC).GH displacement depends on electron spins thanks to Dresselhaus SOC,therefore electron spins can be separated from the space domain and spinpolarized electrons in semiconductors can be *** the magnitude and sign of the spin polarization ratio change with the electron energy,in-plane wave vector,strain engineering and semiconductor layer *** spin polarization ratio approaches a maximum at resonance;however,no electron-spin polarization occurs in the SLSM for a zero in-plane wave *** importantly,the spin polarization ratio can be manipulated by strain engineering or semiconductor layer thickness,giving rise to a controllable spatial electron-spin splitter in the field of semiconductor spintronics.

关键词： semiconductor spintronics single-layered semiconductor microstructure(SLSM) spin-orbit coupling(SOC) Goos-Hänchen(GH)effect electron-spin polarization

Microstructure and wear behaviors of TiB/TiC reinforced Ti2Ni/α(Ti) matrix coating produced by laser cladding

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Rare Metals 2020年第3期39卷 304-315页

作者： Jin-Zhong Shao Jun li Rui Song Lv-lin Bai jia-li chen Cui-Cui Qu School of Materials Engineering Shanghai University of Engineering ScienceShanghai201620China

A Ti2Ni/a(Ti)matrix composite coating reinforced by TiC and TiB was prepared on a Ti6A14V substrate by laser *** microstructure of the coating was examined and *** wear behavior of the coating at various sliding speeds was investigated from the perspective of energy dissipation,and the relationship between accumulated dissipated energy(ΣE)and accumulated wear volume(ΣV)was *** indicate a good linear relationship betweenΣE andΣV at low sliding speed(0.1 m·s-1);at higher sliding speed(0.2 m·s-1),the relationship between these parameters follows a quadratic *** results may be explained from the perspective of energy transformation,wherein the friction heat and plastic deformation of the coating surface consume a substantial amount ofΣE at high sliding speed(0.2 m·s-1)and the remainder of the energy is used to produce worn coating *** wear mechanism of the coating involves a combination of microcutting and brittle debonding accompanied by oxidization of the worn surface and formation of Al2O3 adherents.

关键词： Wear behaviors Coating Laser cladding Accumulated dissipated energy

A numerical method to calculate dwell time for electron in semiconductor nanostructure

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Communications in Theoretical Physics 2023年第1期75卷 162-166页

作者： Shi-Shi Xie Mao-Wang Lu Sai-Yan chen Ying-Jie Qin li Wen jia-li chen College of Science Guilin University of TechnologyGuilin 541004China

To some extent,the operational quickness of semiconductor devices depends on the transmission time of an electron through semiconductor ***,the calculation of transmission time is very difficult,thanks to both the contentious definition of the transmission time in quantum mechanics and the complicated effective potential functions experienced by electrons in semiconductor ***,based on an improved transfer matrix method to numerically solve the Schr?dinger equation and H G Winful’s relationship to calculate the dwell time,we develop a numerical approach to evaluate the transmission time of an electron in semiconductor *** to the exactly resolvable case of the rectangular potential barrier,the established numerical approach possesses high precision and small error,which may be employed to explore the dynamic response and operating speed of semiconductor *** proposed numerical method is successfully applied to the calculation of dwell time for an electron in double rectangular potential barriers and the dependence of transmission time on the number of potential barriers is revealed.

关键词： semiconductor device quantum tunneling effect dwell time improved transfer matrix method H G Winful’s(HGW)relationship

Different types of fruit intake and colorectal cancer risk:A metaanalysis of observational studies

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World Journal of Gastroenterology 2023年第17期29卷 2679-2700页

作者： Zhen-Ying Wu jia-li chen Han li Ke Su Yun-Wei Han Department of Oncology The Affiliated Hospital of Southwest Medical UniversityLuzhou 646099Sichuan ProvinceChina

BACKGROUND Multiple studies investigating the relationship between intake of different types of fruit and colorectal cancer(CRC)risk have yielded inconsistent *** To perform a meta-analysis of existing studies to assess the association between the intake of different kinds of fruit and the incidence of *** We searched online literature databases including PubMed,Embase,WOS,and Cochrane library for relevant articles available up to August *** data extracted from observational studies,odds ratios(ORs)with 95%confidence intervals(CIs)were assessed using random-effects models.A funnel plot and Egger’s test were used to determine publication ***,subgroup analysis and dose-response analysis were *** analyses were conducted using R(version 4.1.3).RESULTS Twenty-four eligible studies involving 1068158 participants were included in this *** meta-analysis showed that compared to a low intake,a higher intake of citrus,apples,watermelon,and kiwi reduced the risk of CRC by 9%[OR(95%CI)=0.91(0.85-0.97)],25%[OR(95%CI)=0.75(0.66-0.85)],26%[OR(95%CI)=0.74(0.58-0.94)],13%[OR(95%CI)=0.87(0.78-0.96)],*** significant association was observed between the intake of other types of fruit and the risk of *** the dose-response analysis,a nonlinear association was found[R(95%CI)=-0.0031(-0.0047 to-0.0014)]between citrus intake and CRC risk(Plinear dose-response relationship with the risk of *** meta-analysis provides further evidence that a higher intake of specific types of fruit is effective in preventing the occurrence of CRC.

关键词： Colorectal cancer Fruit Dose Systematic review Meta-analysis

Epidemiology, clinical characteristics, and treatment of severe fever with thrombocytopenia syndrome

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Infectious Medicine 2022年第1期1卷 40-49页

作者： jia-chen li Jing Zhao Hao li li-Qun Fang Wei liu State Key Laboratory of Pathogen and Biosecurity Beijing Institute of Microbiology and EpidemiologyBeijing100071China

Severe fever with thrombocytopenia syndrome(SFTS)is an emerging tick-borne infectious disease caused by a novel phlebovirus(SFTS virus,SFTSV)in the family Phenuiviridae of the order *** disease causes a wide spectrum of clinical signs and symptoms,ranging from mild febrile disease accompanied by thrombocy-topenia and/or leukocytopenia to hemorrhagic fever,encephalitis,multiple organ failure,and *** was first identified in China and was subsequently reported in South Korea and *** case-fatality rate ranges from 2.7%to 45.7%.Older age has been consistently shown to be the most important predictor of adverse disease *** age exacerbates disease mainly through dysregulation of host immune cells and uncontrolled inflammatory ***-to-human transmission is the primary route of human infection with SFTSV,and Haemaphysalis longicornis is the primary tick vector of *** its high case-fatality rate,vaccines and an-tiviral therapies for SFTS are not currently *** therapeutic efficacies of several antiviral agents against SFTSV are currently being *** was initially identified as a potential antiviral therapy for SFTS but was subsequently found to inefficiently improve disease outcomes,especially among patients with high viral ***(T705)decreased both time to clinical improvement and mortality when administered early in patients with low viral ***-inflammatory agents including corticosteroids have been proposed to play therapeutic ***,the efficacy of other therapeutic modalities,such as convalescent plasma,is not yet clear.

关键词： SFTS Epidemiology Transmission Risk factors Treatment