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The smallest in the deepest: the enigmatic role of viruses in the deep biosphere

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National science Review 2023年第4期10卷 191-202页

作者： Lanlan Cai Markus g.Weinbauer Le xie Rui Zhang state Key Laboratory of Marine Environmental science College of Ocean and Earth Sciences Xiamen University Department of Ocean science The Hong Kong University of Science and Technology sorbonne Universités UPMC Université Paris 06 CNRS Laboratoire d'Océanographie de Villefranche (LOV) Institute for Advanced study Shenzhen University

It is commonly recognized that viruses control the composition, metabolism, and evolutionary trajectories of prokaryotic communities, with resulting vital feedback on ecosystem functioning and nutrient cycling in a wide range of ecosystems. Although the deep biosphere has been estimated to be the largest reservoir for viruses and their prokaryotic hosts, the biology and ecology of viruses therein remain poorly *** deep virosphere is an enigmatic field of study in which many critical questions are still to be *** the deep virosphere simply a repository for deeply preserved, non-functioning virus particles? Or are deep viruses infectious agents that can readily infect suitable hosts and subsequently shape microbial populations and nutrient cycling? Can the cellular content released by viral lysis, and even the organic structures of virions themselves, serve as the source of bioavailable nutrients for microbial activity in the deep biosphere as in other ecosystems? In this review, we synthesize our current knowledge of viruses in the deep biosphere and seek to identify topics with the potential for substantial discoveries in the future.

关键词： virus deep biosphere population size diversity activity ecological role

高速公路对绿色经济效率的影响分析--基于产业结构优化视角

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生态经济 2025年第1期41卷 114-122页

作者：樊建强谢靖雯长安大学经济与管理学院陕西西安710064

当前中国高速公路建设布局日趋完善,探究如何发挥其对地区产业结构优化的有力支持,进而助力绿色经济发展转型具有重要意义。论文基于2006—2019年中原城市群27个城市的面板数据,运用超效率sBM模型测算其绿色经济效率,从产业结构优化的... 详细信息

当前中国高速公路建设布局日趋完善,探究如何发挥其对地区产业结构优化的有力支持,进而助力绿色经济发展转型具有重要意义。论文基于2006—2019年中原城市群27个城市的面板数据,运用超效率sBM模型测算其绿色经济效率,从产业结构优化的视角实证分析了高速公路对绿色经济效率的影响,并以产业结构优化为中介与门槛变量,进一步探讨产业结构优化对于高速公路影响绿色经济效率的门槛效应。研究结果表明:中原城市群高速公路与绿色经济效率间呈现先抑制后促进的“U”型关系;产业结构优化在高速公路和绿色经济效率间发挥部分中介作用;产业结构优化存在单一门槛效应,随着产业结构优化水平的提升,高速公路对绿色经济效率由抑制作用转为促进作用。

关键词：绿色经济效率高速公路产业结构优化超效率sBM 中原城市群

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基于最大影响力集合的主动学习方法

计算机科学 2025年第1期52卷 289-297页

作者：李雅和谢志鹏复旦大学计算机科学技术学院上海200438

随着深度学习技术的不断进步,其已经在许多领域广泛应用。但深度模型的训练需要消耗大量标注数据,时间与资源成本高,如何利用尽可能少的标注数据达到最佳模型效果成为一个重要的研究课题。主动学习的提出正是为了解决这一问题,其旨在选... 详细信息

随着深度学习技术的不断进步,其已经在许多领域广泛应用。但深度模型的训练需要消耗大量标注数据,时间与资源成本高,如何利用尽可能少的标注数据达到最佳模型效果成为一个重要的研究课题。主动学习的提出正是为了解决这一问题,其旨在选择最有价值的样本进行标注并用于模型训练。传统的主动学习策略通常关注不确定性或多样性,旨在查询最困难或最具代表性的样本。然而,在主动学习问题中,这些方法通常没有考虑标注样本和无标注样本之间的交互作用。另一类主动学习方法则使用辅助网络进行样本选择,但这些方法通常会增加计算复杂度。在上述背景下,提出一种新的主动学习算法,旨在通过考虑不同样本之间的相互作用,综合衡量候选样本对其他样本的影响力与不确定性,来最大限度地提高模型的整体性能增益。所提算法首先根据样本隐含层表征之间的距离估计样本相互之间的影响力,进一步根据候选样本的影响力与无标注样本的不确定性估计该样本能够带来的潜在增益,并迭代地选择全局增益最大的样本进行标注。进一步在一系列不同领域的多种任务上将该方法与其他主动学习策略进行了比较,实验结果表明,该方法在所有任务中的表现均显著优于所有基线方法。进一步的量化分析实验也证明该方法在不确定性和多样性之间取得了良好的权衡,并探究了主动学习不同阶段应该注重的因素。

关键词：主动学习深度学习不确定性

Ultra-fast interpretable machine-learning potentials

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npj Computational Materials 2023年第1期9卷 649-657页

作者： stephen R.xie Matthias Rupp Richard g.Hennig Department of Materials science and Engineering University of FloridaGainesvilleFLUSA Quantum Theory Project University of FloridaGainesvilleFLUSA Department of Computer and Information science University of KonstanzKonstanzGermany Materials Research and Technology Department Luxembourg Institute of Science and Technology(LIST)Esch-sur-AlzetteLuxembourg

All-atom dynamics simulations are an indispensable quantitative tool in physics,chemistry,and materials science,but large systems and long simulation times remain challenging due to the trade-off between computational efficiency and predictive *** address this challenge,we combine effective two-and three-body potentials in a cubic B-spline basis with regularized linear regression to obtain machine-learning potentials that are physically interpretable,sufficiently accurate for applications,as fast as the fastest traditional empirical potentials,and two to four orders of magnitude faster than state-of-the-art machine-learning *** data from empirical potentials,we demonstrate the exact retrieval of the *** data from density functional theory,the predicted energies,forces,and derived properties,including phonon spectra,elastic constants,and melting points,closely match those of the reference *** introduced potentials might contribute towards accurate all-atom dynamics simulations of large atomistic systems over long-time scales.

关键词： method spline faster

study of transversity gPDs from pseudoscalar mesons production at EIC of China

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Communications in Theoretical Physics 2023年第6期75卷 86-95页

作者： s V goloskokov Ya-Ping xie Xurong Chen Bogoliubov Laboratory of Theoretical Physics Joint Institute for Nuclear ResearchDubna 141980Moscow regionRussia Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China University of Chinese Academy of sciences Beijing 100049China Institute of Quantum Matter South China Normal UniversityGuangzhou 510006China

The exclusive η and π^(0)electroproduction is studied in the handbag approach based on the generalized parton distributions(gPDs)*** of π^(0)and η mesons are calculated for future electron-ion collider in China(EicC)energy ranges,using obtained cross sections we extract information on the transversity gPDs contributions to these processes.

关键词： meson production general parton distributions handbag method

Deciphering deformation mechanisms of hierarchical dual-phase CrCoNi coatings

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Journal of Materials science & Technology 2020年第4期39卷 7-13页

作者： s.J.Tsianikas Y.Chen Z.xie school of Mechanical Engineering The University of AdelaideAdelaideSA5005Australia Centre for Advanced Thin Film Materials and Device Faculty of Materials and EnergySouthwest UniversityChongqing400715China school of Engineering Edith Cowan UniversityWA6027Australia

Hierarchical Cr Co Ni medium entropy alloy(MEA)thin films with a dual-phase face-centred cubic(FCC)and hexagonal closed-packed(HCP)nanostructure were prepared on M2 steel substrates by closed field unbalanced magnetron *** tests show an ultra-high hardness of 9.5 gPa,attributable to large amounts of innate planar defects(i.e.,growth twins and stacking faults)impeding dislocation motion in the coatings.A deep analysis of undeformed and post-mortem samples reveals grain refinement as the dominant deformation mechanism in FCC dominated regions,while phase transformation and shear banding played major roles in regions occupied by HCP *** grain refinement was facilitated by twin/matrix lamellae,with dislocations piling up and arranging into interconnecting grain *** shear banding was accelerated by innate planar defects in the HCP phase due to a lack of slip *** particular interest is the observation of HCP→FCC phase transformation,which was catalysed by deformation-induced grain reorientation with innate stacking faults acting as embryos to grow the FCC *** results of this work suggest that multiple deformation pathways could be activated in Cr Co Ni coatings with assistance of growth defects,thereby imparting these technically important coatings appreciable ductility.

关键词： Medium entropy alloys sputter deposition grain refinement shear banding Phase transformation

Mechanistic investigation on Ce addition in tuning recrystallization behavior and mechanical property of Mg alloy

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Journal of Materials science & Technology 2023年第1期132卷 1-17页

作者： J.R.Li D.s.xie Z.R.Zeng B.song H.B.xie R.s.Pei H.C.Pan Y.P.Ren g.W.Qin Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education) College of Materials Science and EngineeringNortheastern UniversityShenyang110819China College of Engineering and Computer science Australian National UniversityACT 2601Australia school of Materials and Energy Southwest UniversityChongqing 400715China Institute for Physical Metallurgy and Materials Physics RWTH Aachen UniversityAachen 52062Germany

Constructing bimodal grain structure is a promising approach to achieve the high strength-ductility syn-ergy in Mg *** of bimodal grain is closely related to the dynamic and/or static recrystal-lization process,which has not been fully understood in the typical Mg-RE based *** this work,it is claimed for the first time that the minor Ce addition(∼0.3 wt%)into Mg matrix significantly pro-motes the pyramidaland non-basaldislocations at the early stage of extrusion,which con-sequently enhances the formation of sub-grain boundaries via the movement and recovery of pyramidal II-type*** this stage,fine sub-grain lamellae are widely observed predominantly due to the low migration rate of sub-grain boundary caused by the limited mobility of*** the later stage,the sub-grains continuously transform into dynamic recrystallized(DRXed)grains that have10¯10Taylor axis and also strong fiber texture,indicating substantial activation of pyramidal II-type*** low mobility ofdislocations,accompanied with the solute drag from grain boundary(gB)segregation and pinning from nano-phases,cause a sluggish DRX process and thus a bimodal microstructure with ultra-fined DRXed grains,∼0.51μ*** resultant texture hardening and grain refinement hardening effects,originated from bimodal microstructure,result in a yield strength of∼352 MPa,which is exceptional in Mg-Ce dilute *** work clarifies the critical role of Ce addition in tuning recrystallization behavior and mechanical property of magnesium,and can also shed light on designing the other high-performance Mg alloys.

关键词： Mg alloys Recrystallization behavior Mechanical property Pyramidal dislocation Thermal stability

service-oriented infrastructure for flood mapping using optical and sAR satellite data

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International Journal of Digital Earth 2014年第10期7卷 829-845页

作者： N.Kussul A.shelestov s.skakun g.Li O.Kussul J.xie Department of space Information Technologies and systems Space Research Institute NASU-NSAUKyivUkraine Departemnt of Information security Physics and Technology InstituteNational Technical University of Ukraine“Kyiv Polytechnic Institute”KyivUkraine Department of software Engineering National University of Life and Environmental Sciences of UkraineKyivUkraine Data Technology Division Center of Earth Observation and Digital EarthChinese Academy of SciencesBeijingChina

In this paper,we present the service-oriented infrastructure within the Wide Area grid project that was carried out within the Working group on Information systems and services of the Committee on Earth Observation *** developed infrastructure integrates services and computational resources of several regional and national grid systems:Ukrainian Academician grid(with satellite data processing grid segment,UAspacegrid)and grid system at the Center on Earth Observation and Digital Earth of Chinese Academy of *** study focuses on integrating geo-information services on flood mapping provided by Ukrainian and Chinese entities to benefit from information acquired from multiple *** also describe services for workflow automation and management in grid environment and provide an example of workflow automation for generating flood maps from optical and synthetic-aperture radar satellite *** also discuss issues of enabling trust for the infrastructure using certificates and reputation-based *** of utilizing the developed infrastructure for operational flood mapping in Ukraine and China are given as well.

关键词： earth observation geoinformatics geospatial data integration image processing remote sensing

Dynamic Impact of High-Density Aluminum Foam

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Acta Mechanica solida sinica 2022年第2期35卷 198-214页

作者： Q.Peng J.xie H.s.Ma X.Ling X.Liu Y.g.Wei LNM Institute of MechanicsChinese Academy of SciencesBeijing 100190China school of Engineering science University of Chinese Academy of SciencesBeijing 100049China school of Engineering and Technology China University of GeosciencesBeijing 100083China College of Engineering Peking UniversityBeijing 100871China

High-density aluminum foam can provide higher stiffness and absorb more energy during the impact Obtaining the constitutive law of such foam requires tri-axial tests with very high pressure,where difficulty may arise because the hydrostatic pressure can reach more than 30 *** this paper,instead of using tri-axial tests,we proposed three easier tests-tension,compression and shear to obtain the parameters of constitutive model(the Deshpande-Fleck model).To verify the constitutive model both statically and dynamically,we carried out addi-tional triaxial tests and direct impact tests,*** on the derived model,we performed finite element simulation to study the impact response of the present *** dimensional analysis,we proposed an empirical equation for a non-dimensional impact time the impact time divided by the time required for plastic wave travelling from the impact surface to the bottom surface,to det ermine the deformation charac teristic of the aluminum foam after *** the case with t_(d)≤1,the deformation tends to exhibit a shock-type characteristic,while for the case with t_(d)>5,the deformation tends to exhibit an upsetting-type characteristic.

关键词： High density aluminum Foam Deshpande-Fleck model Finite element method Impact analysis Plastic wave