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Optimization of Random Feature Method in the High-Precision Regime

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Communications on Applied Mathematics and Computation 2024年第2期6卷 1490-1517页

作者： Jingrun chen Weinan e Yifei sun school of Mathematical sciences and suzhou Institute for Advanced Research Suzhou 215006JiangsuChina University of science and Technology of China Hefei 230026AnhuiChina Center for Machine Learning Research and school of Mathematical sciences Peking UniversityBeijing 100871China AI for science Institute Beijing 100084China school of Mathematical sciences Soochow UniversitySuzhou 215006JiangsuChina

Machine learning has been widely used for solving partial differential equations(PDes)in recent years,among which the random feature method(RFM)exhibits spectral accuracy and can compete with traditional solvers in terms of both accuracy and ***,the optimization problem in the RFM is more difficult to solve than those that arise in traditional *** the broader machine-learning research,which frequently targets tasks within the low-precision regime,our study focuses on the high-precision regime crucial for solving *** this work,we study this problem from the following aspects:(i)we analyze the coeffcient matrix that arises in the RFM by studying the distribution of singular values;(ii)we investigate whether the continuous training causes the overfitting issue;(ii)we test direct and iterative methods as well as randomized methods for solving the optimization *** on these results,we find that direct methods are superior to other methods if memory is not an issue,while iterative methods typically have low accuracy and can be improved by preconditioning to some extent.

关键词： Random feature method(RFM) Partial differential equation(PDe) Least-squares problem Direct method Iterative method

Optimization of performance of the KM2A full array using the Crab Nebula

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Chinese Physics C 2024年第6期48卷 169-178页

作者：曹臻 F.Aharonian 安琪阿西克古白云翔包逸炜 D.Bastieri 毕效军毕玉江蔡金庭曹晴曹文羽曹喆常进常劲帆陈尚明陈恩生陈亮陈林陈龙陈明君陈玛丽陈起辉陈素弘陈天禄陈阳程宁程耀东崔明阳崔树旺崔晓红崔昱东戴本忠代洪亮戴子高单增罗布 D.della Volpe 董绪强段凯凯樊军辉范一中方军方堃冯存峰封莉冯少辉丰晓婷冯有亮 s.Gabici 高博高川东高林青高启高卫高伟康葛茂茂耿利斯 G.Giacinti 龚光华苟全补顾旻皓郭福来郭晓磊郭义庆郭莹莹韩毅昂何会海贺昊宁何佳银何新波何钰 M.Heller 贺远强侯博文侯超侯贤胡红波胡铨胡世聪黄代绘黄天奇黄文俊黄性涛黄晓渊黄勇黄志成季筱璐贾焕玉贾康江琨姜晓巍姜泽军金敏康明铭柯通 D.Kuleshov.K.Kurinov 李兵兵李澄李骢李丹李飞李海波李会财李华阳李军李剑李捷李凯李文龙李文莲李秀荣李昕李一卓李哲黎卓梁恩维梁云峰林苏杰刘冰刘成刘栋刘虎刘海东刘佳刘江来刘金艳刘茂元柳若愚刘四明刘伟刘怡刘以农鲁睿罗晴吕洪魁马伯强马玲玲马欣华毛基荣闵振 W.Mitthumsiri 穆慧君南云程 A.Neronov 区子维庞彬宇 P.Pattarakijwanich 裴致远齐孟尧祁业情乔冰强秦家军 D.Ruffolo A.sáiz D.semikoz 邵澄宇邵琅 O.shchegolev 盛祥东舒富文宋慧超 Yu.V.stenkin V.stepanov 苏扬孙秦宁孙晓娜孙志斌谭柏轩唐庆文唐泽波田文武王超王昌贝王广威王洪光王惠惠王建成汪凯王利苹王玲玉王培汉王冉王为王祥高王祥玉王阳王玉东王岩谨王忠海王仲翔王振王铮韦大明魏俊杰魏永健文韬吴超勇吴含荣武莎吴雪峰吴雨生席邵强夏捷夏君集项光漫肖迪泫肖刚辛广广辛玉良邢祎熊峥徐东莲徐仁峰徐仁新徐伟立薛良闫大海颜景志颜田杨朝文杨帆杨冯帆杨何文杨佳盈杨莉莉杨明洁杨睿智杨深邦姚玉华姚志国叶一锰尹丽巧尹娜游晓浩游智勇于艳红袁强岳华曾厚敦曾婷轩曾玮查敏张彬彬张丰张海明张恒英张建立张丽霞张力张鹏飞张佩佩张瑞张少博张少如张寿山张潇张笑鹏张云峰张毅张勇赵兵赵静赵雷赵立志赵世平郑福周斌周浩周佳能周猛周平周荣周勋秀祝成光祝凤荣朱辉朱科军左雄 LHAAsO Collaboration Key Laboratory of Particle Astrophyics&experimental Physics Division&Computing Center Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China University of Chinese Academy of sciences Beijing 100049China Tianfu Cosmic Ray Research Center Chengdu 610000China Dublin Institute for Advanced studies 31 Fitzwilliam Place2 DublinIreland Max-Planck-Institut for Nuclear Physics P.O.Box 10398069029 HeidelbergGermany state Key Laboratory of Particle Detection and electronics China University of science and Technology of China Hefei 230026China school of Physical science and Technology&school of Information science and Technology Southwest Jiaotong UniversityChengdu 610031China school of Astronomy and space science Nanjing UniversityNanjing 210023China Center for Astrophysics Guangzhou UniversityGuangzhou 510006China Hebei Normal University Shijiazhuang 050024China Key Laboratory of Dark Matter and space Astronomy&Key Laboratory of Radio Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing 210023China Tsung-Dao Lee Institute&school of Physics and Astronomy Shanghai Jiao Tong UniversityShanghai 200240China Key Laboratory for Research in Galaxies and Cosmology Shanghai Astronomical ObservatoryChinese Academy of SciencesShanghai 200030China Key Laboratory of Cosmic Rays(Tibet University) Ministry of EducationLhasa 850000TibetChina National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China school of Physics and Astronomy(Zhuhai)&school of Physics(Guangzhou)&sino-French Institute of Nuclear engineering and Technology(Zhuhai) Sun Yat-sen UniversityZhuhai 519000&Guangzhou 510275China school of Physics and Astronomy Yunnan UniversityKunming 650091China Département de Physique Nucléaire et Corpusculaire Facultéde SciencesUniversitéde Genève24 Quai Ernest Ansermet1211 GenevaSwitzerland Institute of Frontier and Interdisciplinary science Shandong UniversityQingdao 266237China APC Universit'e Paris Cit'eCNRS/IN2P3CEA/IRFUObservat

The full array of the Large High Altitude Air shower Observatory(LHAAsO)has been in operation since July *** its kilometer-square array(KM2A),we optimized the selection criteria for very high and ultrahigh energyγ-rays using data collected from August 2021 to August 2022,resulting in an improvement in significance of the detection in the Crab Nebula of approximately 15%,compared with that of previous *** the implementation of these new selection criteria,the angular resolution was also significantly improved by approximately 10%at tens of *** aspects of the full KM2A array performance,such as the pointing error,were also calibrated using the Crab *** resulting energy spectrum of the Crab Nebula in the energy range of 10-1000 TeV are well fitted by a log-parabola model,which is consistent with the previous results from LHAAsO and other experiments.

关键词： γ-ray Crab Nebula significance

OsbZIP53 Negatively Regulates Immunity Response by Involving in Reactive Oxygen species and salicylic Acid Metabolism in Rice

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Rice science 2024年第2期31卷 190-202,I0022-I0028页

作者： WU Lijuan HAN Cong WANG Huimei He Yuchang LIN Hai WANG Lei chen chen e Zhiguo state Key Laboratory of Rice Biology and Breeding China National Rice Research InstituteHangzhou 310006China Jiangsu Key Laboratory of Crop Genetics and Physiology/Key Laboratory of Plant Functional Genomics of the Ministry of education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops Agricultural College of Yangzhou UniversityYangzhou 225009China

The basic region/leucine zipper(bZIP)transcription factors play important roles in plant development and responses to abiotic and biotic ***53 regulates resistance to Magnaporthe oryzae in rice by analyzing APIP5-RNAi transgenic *** further investigate the biological functions of OsbZIP53,we generated osbzip53 mutants using CRIsPR/Cas9 editing and also constructed OsbZIP53 over-expression transgenic *** analysis of phenotypical,physiological,and transcriptional data showed that knocking-out OsbZIP53 not only improved disease resistance by inducing a hypersensitivity response in plants,but also regulated the immune response through the salicylic acid ***,disrupting OsbZIP53 increased H2O2 accumulation by promoting reactive oxygen species generation through up-regulation of several respiratory burst oxidase homologs(Osrboh genes)and weakened H2O2 degradation by directly targeting *** addition,the growth of osbzip53 mutants was seriously impaired,while OsbZIP53 over-expression lines displayed a similar phenotype to the wild type,suggesting that OsbZIP53 has a balancing effect on rice immune response and growth.

关键词： OsbZIP53 hypersensitive response reactive oxygen species metabolism rice immunity salicylic acid transcription factor

Nonlinear wave dispersion in monoatomic chains with lumped and distributed masses:discrete and continuum models

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Applied Mathematics and Mechanics(english edition) 2024年第4期45卷 633-648页

作者： e.GHAVANLOO s.eL-BORGI school of Mechanical engineering Shiraz UniversityShiraz 71963-16548Iran Mechanical engineering Program Texas A&M University at QatarDoha 23874Qatar

The main objective of this paper is to investigate the influence of inertia of nonlinear springs on the dispersion behavior of discrete monoatomic chains with lumped and distributed *** developed model can represent the wave propagation problem in a non-homogeneous material consisting of heavy inclusions embedded in a *** inclusions are idealized by lumped masses,and the matrix between adjacent inclusions is modeled by a nonlinear spring with distributed ***,the model is capable of depicting the wave propagation in bi-material bars,wherein the first material is represented by a rigid particle and the second one is represented by a nonlinear spring with distributed *** discrete model of the nonlinear monoatomic chain with lumped and distributed masses is first considered,and a closed-form expression of the dispersion relation is obtained by the second-order Lindstedt-Poincare method(LPM).Next,a continuum model for the nonlinear monoatomic chain is derived directly from its discrete lattice model by a suitable continualization *** subsequent use of the second-order method of multiple scales(MMs)facilitates the derivation of the corresponding nonlinear dispersion relation in a closed *** novelties of the present study consist of(i)considering the inertia of nonlinear springs on the dispersion behavior of the discrete mass-spring chains;(ii)developing the second-order LPM for the wave propagation in the discrete chains;and(iii)deriving a continuum model for the nonlinear monoatomic chains with lumped and distributed ***,a parametric study is conducted to examine the effects of the design parameters and the distributed spring mass on the nonlinear dispersion relations and phase velocities obtained from both the discrete and continuum *** parameters include the ratio of the spring mass to the lumped mass,the nonlinear stiffness coefficient of the spring,and the wave amplitude.

关键词： nonlinear mass-spring chain discrete model continuum model LindstedtPoincare method(LPM) method of multiple scales(MMs) dispersion phase velocity

scanning transmission electron microscopy and atom probe tomography analysis of non-stoichiometry long-period-stacking-ordered structures in Mg-Ni-Y/sm alloys

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Journal of Magnesium and Alloys 2024年第3期12卷 954-965页

作者： Yimeng chen Manuel Legrée Jean-Louis Bobet Alexander Kvit CAMeCA Instruments Inc MadisonWI 53711USA ICMCB Universitéde BordeauxPessacCEDEX 33608France NIAC&Materials science Department University of WisconsinMadisonWI 53706USA

The long-period-stacking-ordered(LPsO)structure affects the mechanical,corrosion and hydrolysis properties of Mg *** current work employs high angle annular dark field-scanning transmission electron microscopy(HAADF-sTeM)and atom probe tomography(APT)to investigate the structural and local chemical information of LPsO phases formed in Mg-Ni-Y/sm ternary alloys after extended isothermal *** on the alloying elements and their concentrations,Mg-Ni-Y/sm develops a two-phase LPsO+α-Mg structure in which the LPsO phase contains defects,hybrid LPsO structure,and Mg ***-sTeM and APT indicate non-stoichiometric LPsO with incomplete Ni_(6)(Y/sm)_(8) *** addition,the APT quantitatively determines the local composition of LPsO and confirms the presence of Ni within the Mg bonding *** results provide insight into a better understanding of the structure and hydrolysis properties of LPsO-Mg alloys.

关键词： Magnesium alloys Long-range ordering Atom probe tomography(APT) sTeM HAADF Hydrolysis properties.

New record of the feather star Palaeocomatella hiwia(echinodermata:Crinoidea:Comatulida)from Zhenbei seamount in south China sea:new insights into the taxonomic position of Palaeocomatella

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Journal of Oceanology and Limnology 2024年第1期42卷 244-251页

作者： shao’e sUN Zijie MeI Zhongli sHA Jing WANG Nansheng chen Department of Marine Organism Taxonomy and Phylogeny Institute of OceanologyChinese Academy of SciencesQingdao 266071China CAs Key Laboratory of Marine ecology and environmental sciences Institute of OceanologyChinese Academy of SciencesQingdao 266071China Laoshan Laboratory Qingdao 266237China shandong Province Key Laboratory of experimental Marine Biology Institute of OceanologyChinese Academy of SciencesQingdao 266071China Center for Ocean Mega-science Chinese Academy of SciencesQingdao 266071China University of Chinese Academy of sciences Beijing 100049China

One specimen belonging to the family Comatellinae was collected from the Zhenbei seamount(332.5–478.2 m)in the south China sea in July *** on the morphological characters,the specimen was identified as Palaeocomatella hiwia McKnight,*** is first recorded from China sea and redescribed in *** specimen differs from the original description from New Zealand for never showing syzygy at br4+5 or br5+6 on interior and br1+2 on exterior ***,it is much conform to the redescription to specimens from Indonesia,with only differences in position of the second syzygy and distalmost pinnule *** is deposited in the Institute of Oceanology,Chinese Academy of *** analyses based on the mitochondrial c oxidase subunit I(COI)and 16s rRNA genes indicated that *** was nested within the tribe Phanogeniini and clustered with Aphanocomaster ***,*** showed same morphological features in terms of mouth placement,comb location,and number of comb teeth rows as other genera of ***,we suggest that the genus Palaeocomatella should be put in the tribe Phanogeniini.

关键词： new record Palaeocomatella hiwia McKnight 1977 south China sea phylogenetic relationship taxonomy

Integrated stratigraphy and Mineralogy of the Doushantuo Formation in Weng’an,south China,and Implications for ediacaran Phosphogenesis

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Journal of earth science 2024年第2期35卷 476-503页

作者： Liangxuan Jiao Zhenbing she Dominic Papineau Yaguan Zhang Matthew s.Dodd Kenan Cao Qun chen Guoyong chen state Key Laboratory of Biogeology and environmental Geology China University of GeosciencesWuhan430078China school of earth sciences China University of GeosciencesWuhan430047China London Centre for Nanotechnology University College London17-19 Gordon StreetLondonWC1E 6BTUK Department of earth sciences University College LondonLondonWC1E 6BTUK Centre for Planetary science University College London and Birkbeck CollegeLondonWC1E 7HXUK Innovation Center of Ore Resources exploration Technology in the Region of Bedrock Ministry of Natural Resources of People’s Republic of China’Guiyang550000China Guizhou Bureau of Geology and Mineral exploration and Development Guiyang550000China

The ediacaran–Cambrian Phosphogenic episode is the earth’s first true phosphogenic event and resulted in worldwide phosphate deposits,which occurred during the processes of the Neoproterozoic Oxygenation *** ediacaran Doushantuo Formation(ca.635–551 Ma)of Weng’an area in central Guizhou,south China,contains two economic phosphorite beds(the Lower and Upper Phosphorite Beds).This paper presents a detailed stratigraphic,sedimentological and mineralogical study of multiple outcrop and drill core sections of the Doushantuo Formation across the Weng’an area,and identified 11 lithofacies and 4 types of phosphatic *** differences in lithofacies and grain types between the upper and lower phosphate deposits are observed,indicating that the two sets of phosphate deposits are the products of two distinct phosphogenic *** Lower Phosphorite Bed mainly consists of banded and laminated phosphorites,contains micro-oncoids formed by microbially-mediated precipitation and peloids formed by in-situ chemically oscillating reactions,indicating a biochemical and chemical enrichment of phosphorus to sediments during the early ediacaran *** Upper Phosphorite Bed is mainly composed of carbonaceous,massive,and stromatolitic phosphorites,contains bioclasts(phosphatized spheroidal fossils),and intraclasts formed by hydrodynamic agitation,suggesting that the major accesses of phosphorus to sediments were the remineralization of organic *** of the two economic phosphorite beds was controlled by two sea-level *** differences have also been documented in contemporaneous phosphate-bearing successions in Brazil and Mangolia,indicating a significant shift in global phosphogenic mechanism during the early and middle ediacaran,which may be due to the changes in redox conditions in seawater,associated with the Neoproterozoic Oxygenation *** regional active P-cycle processes could produce more free oxygen,which may have contributed to the up

关键词： phosphorite lithofacies phosphatic grains phosphogenic paragenesis phosphorus cycle mineralogy

emission colour tuning in KLnF_(4):Yb^(3+),er^(3+)/Ho^(3+)phosphor

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Journal of Rare earths 2024年第1期42卷 57-65,I0002页

作者： Janani K Gayathri e Vijayatha V Ramasubramanian s Thiyagarajan P Department of science and Humanities Nehru Institute of TechnologyKaliapuramThirumalayampalayamCoimbatoreIndia Department of sciences Amrita School of Physical SciencesAmrita Vishwa VidyapeethamCoimbatoreIndia Department of Physics Anna UniversityChennaiIndia

KLnF_(4):Yb^(3+),er^(3+)/Ho^(3+)(Ln=Y,Yb,Gd)phosphors were prepared by solid-state reaction *** each of the Yb^(3+)/er^(3+)and Yb^(3+)/Ho^(3+)co-doped phosphors independently,phase confirmation and morphological examination were accomplished using the X-ray diffraction technique and scanning electron microscope analysis.X-ray photoelectron spectroscopy analysis shows the charge state and existence of lanthanides and *** luminescence emissions of green and red colour were detected for the synthesized *** changes in the upconverted emission intensities and colour output pertaining to the change of the lanthanide host matrix along with dopants were investigated for the prepared *** the upconversion luminescence,erbium-doped samples exhibit a predominance of red emission while holmium-doped samples display a prevalence of green *** rare-earth er/Ho doped KYbF4shows strong red emission compared to other ***_(4):Yb,er/Ho exhibits relatively significant green upconve rsion emissions,while Yb,er-doped KGdF_(4)host displays a 10-fold increase in green/red emission ratio with an increase in the input power of 20-780 *** photoluminescence studies and decay curve analysis were carried out using UV light excitation for the developed phosphors.A higher lifetime of 2.2 ms was measured for the downshifting red emission in the Ho doped KYbF_(4)*** study suggests a potential for colour tunability in the upconversion and downshifting emissions through host modifications to the fluoride phosphor.

关键词： Rare earths energy transfer upconversion Downshifting Colour coordinates

Meridional deflection of global eddy propagation derived from tandem altimetry: Mechanism and implication

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science China earth sciences 2024年第3期67卷 811-825页

作者： Ge chen Xiaoyan chen Frontiers science Center for Deep Ocean Multispheres and earth system School of Marine TechnologyOcean University of ChinaQindao 266100China Laboratory for Regional Oceanography and Numerical Modeling Laoshan LaboratoryQindao 266237China

A common view on meridional deflection of eddy propagation is poleward for cyclones and equatorward for anticyclones. This widely accepted polarity-sensitive pattern has been increasingly undermined given that it is systematically violated on both zonal and regional scales as recently reported. Here, we approach the problem by exploring these violations in terms of eddy effects of spatiotemporal geostrophy, thermal fading, and flow dragging, yielding the following main conclusions.(1) The polarity-dependent deflection discrepancy is a pseudo feature resulting from a biased fit to the normalized eddy tracks which are spatially asymmetric(though azimuthally symmetric) between the two signs;Instead, the primary pattern of eddy deflection appears to be geographically correlated and polarity independent.(2) Geostrophic adjustment plays a critical role in defining the meridional movement of an eddy. specifically, a consistent poleward(equatorward) trajectory bending of spatially(temporally) ageostrophic eddies is observed irrespective of their polarity.(3) The mechanism of eddy deflection is also determined by its zonal propagation direction. Westward propagating eddies are substantially affected by thermal fading, while opposite ones by flow dragging. A realistic and comprehensive understanding of eddy deflection mechanisms serves as a significant contribution to the prediction of eddy trajectory, and the protection of ocean environment.

关键词： Mesoscale eddies eddy propagation eddy meridional deflection satellite observation Geostrophic adjustment

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