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Interface dominated deformation transition from inhomogeneous to apparent homogeneous mode in amorphous/amorphous nanolaminates

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Journal of Materials Science & Technology 2022年第4期99卷 178-183页

作者： Z.q.chen M.c.Li J.S.cao F.c.Li S.W.Guo B.A.Sun h.B.Ke W.h.Wang Songshan Lake Materials Laboratory Dongguan 523808PR China Institute of Physics Chinese Academy of SciencesBeijing 100190PR China Institute of Materials engineering Nanjing UniversityNantong 226019PR China School of Physics Science and Technology Xinjiang UniversityXinjiang 830046PR China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049PR China State Key Laboratory for Mechanical Behavior of Material Xi'an Jiaotong UniversityXi’an 710049PR China

The amorphous/amorphous nanolaminates(A/ANLs)have aroused great attentions owing to their tunable structure and enhanced mechanical ***,the plastic deformation mechanism of A/ANLs have yet been ***,we systematically examined the mechanical properties and deformation behavior of series of NiNb/ZrcuNi Al A/ANLs via nanoindentaion *** was found that both the amount and morphology of amorphous/amorphous interface(A/AIs)played crucial roles in the plastic deformation of A/*** and straighter A/AIs facilitated multiple shear banding deformation,of which the hardness increased with decreasing layer thickness,as the A/AIs hindered the propagation of shear bands(SBs).Whilst,more and wavier A/AIs promoted homogeneous deformation,of which the hardness stayed at a much lower value and was relatively irrelevant with the layer thickness,for the promoted activation of shear transformation zones by A/*** results provide guidance for modifying the mechanical properties of amorphous alloys with interface engineering design.

关键词： Amorphous alloys Nanolaminates Shear bands hardness Interface

Water and thermal conditions variation and the vegetation response at semi⁃ arid Basin

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Shengtai Xuebao 2024年第16期44卷 7198-7212页

作者： Fang q. Zhang S. Wang G. Wang Y. Duan L. Liu T. Yao J. School of Water conservancy and hydropower engineering North China Electric Power University Beijing 102206 China college of Water Sciences Beijing Normal University Beijing 100875 China The college of Water conservancy and civil engineering Inner Mongolia Agricultural University Hohhot 010018 China The School of Ecology and environment Inner Mongolia University Hohhot 010021 China

Recently, most semi⁃arid basins in china have experienced vegetation greening under significant water and thermal conditions changes, which has exacerbated the shortage of water resources despite the positive effect of increasing carbon sinks and reducing carbon emissions. The study of vegetation response under variations of water and thermal conditions can help to understand the mechanism of the balance between the hydrological processes and vegetation pattern and is of great significance for the sustainable utilization of water resources and ecological protection. however, few studies have focused on the time⁃periodic and segmented response mechanisms of vegetation dynamics to variations of water and thermal conditions, resulting in unclear mechanisms of trade⁃off between vegetation greening and water resources. This study analyzed the varied trends of water and thermal conditions and discussed the spatio⁃temporal response of vegetation from two points: overall trends and varied processes at the upper and middle hailar River Basin from 1980 to 2012 by using trends and wavelet period analysis. The results show that: (1) spatially, the average annual precipitation increased and the temperature decreased from west (grassland) to east (forest). compared with the grassland area, the runoff and the Normalized Difference Vegetation Index (NDVI) in the forest area showed larger, and indicated slower warming and larger precipitation declining. (2) Temporally, the average annual precipitation and the runoff slightly decreased with a trend of 10 mm/ 10 a and 19.3 mm/ 10 a, respectively; the average annual temperature and NDVI in the growing season increased significantly with a trend of 0.65 ℃ / 10 a and 0.003—0.006/ 10 a, respectively. The results suggested that warming and drying inhibited the runoff and increased the vegetation growth, even in the context of precipitation increased and smooth increasing trend of temperature after 1998, showing the accumulative effect of w

关键词： runoff variations vegetation response water and thermal conditions water stress

Automotive revolution and carbon neutrality

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Frontiers in energy 2023年第6期17卷 693-703页

作者： c.c.chAN Wei hAN hanlei TIAN Yanbing LIU Tianlu MA c.q.JIANG Department of Electrical and Electronic engineering The University of Hong KongHong KongChina Sustainable energy and environment Thrust Hong Kong University of Science and Technology(Guangzhou)Guangzhou 511453China Department of Electronic and computer engineering Hong Kong University of Science and TechnologyHong KongChina Department of Electrical engineering City University of Hong KongHong KongChina hKUST Shenzhen-hong Kong collaborative Innovation Research Institute Shenzhen 518048China

The automotive industry is in the midst of a groundbreaking revolution,driven by the imperative to achieve intelligent driving and carbon neutrality.A crucial aspect of this transformation is the transition to electric vehicles(EVs),which necessitates widespread changes throughout the entire automotive *** paper examines the challenges and opportunities of this transition,including automotive electrification,intelligence-connected transportation system,and the potential for new technologies such as hydrogen fuel ***,it discusses the key technologies and progress of the hydrogen energy industry chain in the upstream hydrogen production,midstream hydrogen storage and transportation,downstream hydrogen station construction and hydrogen fuel cells in ***,it proposes the directions for future layout,providing guidance for future development.

关键词： automotive revolution electric vehicles(EVs) hydrogen energy fuel cell

characterization of face-centered cubic structure and deformation mechanisms in high energy shot peening process of Tc17

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Journal of Materials Science & Technology 2022年第15期110卷 136-151页

作者： c.Yang M.q.Li Y.G.Liu School of Materials Science and engineering Northwestern Polytechnical UniversityXi’an 710072China

The face-centered cubic structure(fcc)and its deformation behaviors,as well as the distinctive role of fcc-Ti in nanocrystallization in Tc17 subjected to high energy shot peening(hESP),were investigated by using comprehensive high-resolution transmission electron microscopy(hRTEM).The results showed that there was a stress-induced fcc-Ti in Tc17 with a lattice constant of 0.420–0.433 nm and the B-type orientation relationship between the hcp-Ti and the fcc-Ti as[2-1-10]_(hcp)//[-110]_(fcc)and(0001)_(hcp)//(111)_(fcc),which was accomplished by the gliding of Shockley partial dislocations with Burgers vector of 1/3[01-10]on the basal *** deformation twinning dominated the subsequent deformation of fcc-Ti,producing two types of{111}twins with different *** them,the I-type twin with complete structure was generated by successive gliding of Shockley partial dislocations with the same Burgers vector of 1/6[11-2].In contrast,the cooperative slip of three Shockley partials,whose sum of Burgers vectors was equal to zero,produced the II-type twin with zero net macroscopic *** then,the emission of Shockley partial with the Burgers vector of 1/6[11-2]on every three(111)fccplanes resulted in the formation of a 9R *** to the dissociation effect of lamellar fcc-Ti and the superior deformation ability of fcc structure,the occurrence of fcc-Ti effectively promoted surface nanocrystallization of Tc17.

关键词： Tc17 Severe plastic deformation Stress-induced phase transformation Deformation twinning Nanocrystallization

青藏高原及其周边新近纪综合地层、生物群与古地理演化

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中国科学：地球科学 2024年第4期54卷 1343-1378页

作者：邓涛方小敏李强王世骐吴飞翔侯素宽马姣江左其杲孙丹辉郑妍史勤勤孙博阳李录中国科学院古脊椎动物与古人类研究所中国科学院脊椎动物演化与人类起源重点实验室北京100044 中国科学院生物演化与环境卓越创新中心北京100044 中国科学院大学地球与行星科学学院北京100049 中国科学院青藏高原研究所中国科学院青藏高原地球科学卓越创新中心北京100101 北京大学地球与空间科学学院造山带与地壳演化教育部重点实验室北京100871

青藏高原在新近纪的显著隆升对东亚乃至全球的气候环境产生了巨大的影响,因此,建立青藏高原新近纪地层框架对地球科学各领域的研究都有重要的意义.国际新近纪年代地层系统以海相为标准,分为中新统的6个阶和上新统的2个阶.新生代以来,陆... 详细信息

青藏高原在新近纪的显著隆升对东亚乃至全球的气候环境产生了巨大的影响,因此,建立青藏高原新近纪地层框架对地球科学各领域的研究都有重要的意义.国际新近纪年代地层系统以海相为标准,分为中新统的6个阶和上新统的2个阶.新生代以来,陆相地层在陆地上所占的比例迅速增加,到新近纪时已远远超过海相地层,在青藏高原及其周边地区几乎全部为陆相地层.中国的中新统包括5个阶,上新统包括2个阶,除中中新统的通古尔阶以15Ma为底界外,其余各阶都与对应的国际海相阶具有相同的古地磁定义和时限.哺乳动物化石在新生代陆相地层的划分对比中占有非常重要的地位,在新近系尤其倚重于啮齿类、食肉类、长鼻类、奇蹄类和偶蹄类化石.青藏高原有不少地层出露好且富含哺乳动物化石的盆地,新近系谢家阶和灞河阶的底界层型剖面分别位于西宁盆地和临夏盆地,并有精细的古地磁定年与哺乳动物化石相互配合,其余各阶的底界在青藏高原也可以有效确定.东亚地区许多哺乳动物首现属出现在青藏高原及其周边地区,在东北缘的临夏盆地和西南缘的西瓦立克地区尤为典型,其中,西瓦立克的原恐象Prodeinotherium首现于中新统底界,旧大陆最早的三趾马hipparion首现于临夏盆地的灞河阶底界.对青藏高原及其周缘地区新生代沉积物及其所含的哺乳动物化石进行的牙釉质和古土壤碳氧同位素分析重建了气候环境背景及植被发育特征,发现其既与全球变化相关,又有地区性的特点.根据碳同位素变化得到的晚中新世c4植物扩张事件证据来自于青藏高原南缘,但形成鲜明对比的是,多个食草哺乳动物类群和古土壤碳酸盐及有机质的δ13c指示在青藏高原北缘直到新近纪末期仍然缺少明确或显著的c4植物信号.δ^(18)O分析显示在新生代存在几次重大的气候变化事件,尤其是晚中新世末期约7Ma的δ^(18)O正漂指示了青藏高原南北两侧向更干旱环境的转变.青藏高原在晚中新世的强烈隆升强化了海陆热力对比,由此加强了季风环流并导致c4植被在南亚扩张,但能够为中国北方带来大气降水和c4植物适宜气候的东亚夏季风还不足以影响到青藏高原北部地区.青藏高原在中新世整体上已上升至海拔3000m左右,成为阻碍大型哺乳动物交流的屏障;至上新世达到4000m以上的现代海拔高度,由此形成冰冻圈环境,导致冰期动物群祖先类型出现.

关键词：青藏高原新近系陆相地层哺乳动物化石古地磁

constructing an energy Function for Power Systems with DFIGWT Generation Based on a Synchronous-generator-mimicking Model

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cSEE Journal of Power and energy Systems 2022年第1期8卷 64-75页

作者： Yang Liu chenying Xu Zehui Lin Kaishun Xiahou q.h.Wu the School of Electric Power engineering South China University of TechnologyGuangzhou 510640China

In this paper we construct an energy function for multi-machine power systems with doubly-fed induction generator-based wind turbine(DFIGWT)according to a synchronous-generator-mimicking(SGM)model of the *** SGM model is proposed to approximate the dynamics of a *** to the modelling of a synchronous generator(SG),the internal dynamics of a DFIGWT are also described with differential equations of newly constructed virtual rotor angle and internal electromotive force(EMF)in the SGM ***,the power flow of a DFIGWT is expressed by nonlinear functions of its virtual rotor angle and internal *** SGM model bridges the gap between the irregular and complex modelling of DFIGWTs and the well-developed energy function construction techniques for SG *** on the SGM model,a numerical energy function is constructed for power systems with DFIGWT *** theoretical analysis and numerical studies were undertaken to validate that the proposed energy function satisfies the necessary conditions for an energy function of a power system.

关键词： DFIGWT energy function multi-machine power systems synchronous-generator-mimicking model

Laboratory study of fracture initiation and propagation in Barre granite under fluid pressure at stress state close to failure

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Journal of Rock Mechanics and Geotechnical engineering 2023年第3期15卷 538-550页

作者： Bing q.Li Michela casanova herbert h.Einstein Department of civil and environmental engineering Massachusetts Institute of TechnologyCambridgeUSA Department of civil and environmental engineering Western UniversityLondonCanada School of Architecture Civil and Environmental EngineeringÉcole Polytechnique Fédérale de LausanneLausanneSwitzerland

hydraulic fracturing is frequently used to increase the permeability of rock formations in energy extraction scenarios such as unconventional oil and gas extraction and enhanced geothermal systems(EGSs).The present study addresses uncertainties in the hydraulic fracturing process pertaining to EGSs in crystalline rock such as ***,there is debate in the literature on the mechanisms(*** and/or shear)by which these fractures initiate,propagate,and *** present experiments on Barre granite with pre-cut flaws where the material is loaded to high far-field stresses close to shear failure,and then the fluid pressure in the flaws is increased to move the Mohr’s circle to the left and observe the initiation and propagation of fractures using high-speed imaging and acoustic emissions(AEs).We find that the hydraulic fractures initiate as tensile microcracks at the flaw tips,and then propagate as a combination of tensile and shear *** focal mechanisms also show elevated levels of tensional microfracturing near the flaw tips during pressurization and final *** then consider a numerical model of the experimental setup,where we find that fractures are indeed likely to initiate at flaw tips in tension even at relatively high far-field stresses of 40 MPa where shear failure is generally expected.

关键词： Acoustic emission(AE) hydraulic fracturing enhanced geothermal system(EGS) Microseismicity

Further investigation on the fusion of ^(6)Li with ^(209)Bi target at near-barrier energies

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chinese Physics c 2024年第7期48卷 106-117页

作者：张高龙焦振威张广鑫 M.R.cortes 胡世鹏钱建强 D.Mengoni 屈卫卫李聪博郑云张焕乔孙慧斌王楠张春雷 J.J.Valiente-Dobón D.Testov M.Mazzocco A.Gozzelino c.Parascandolo D.Pierroutsakou M.La commara A.Goasduff D.Bazzacco D.R.Napoli F.Galtarossa F.Recchia A.Illana S.Bakes I.Zanon S.Aydin G.de Angelis M.Siciliano R.Menegazzo S.M.Lenzi J.L.Ferreira J.Rangel Serkan Akkoyun L.F.canto J.Lubian School of Physics Beihang UniversityBeijing 100191China Sino-French Institute of Nuclear engineering and Technology Sun Yat-Sen UniversityZhuhai 519082China Instituto de Física Universidade Federal Fluminense24210-340NiteróiRio de JaneiroBrazil Institute for Advanced Study in Nuclear energy&Safety Shenzhen UniversityShenzhen 518060China Shenzhen Key Laboratory of Research and Manufacture of high Purity Germanium Materials and Fetectors Shenzhen UniversityShenzhen 518060China INFN Sezione di PadovaPadovaItaly Dipartimento di fisica Astronomia dell'Universita di padova PadovaItaly State Key Laboratory of Radiation Medicine and Protection School of Radiation Medicine and ProtectionSoochow UniversitySuzhou 215123China china Institute of Atomic energy Beijing 102413China The Key Laboratory of Beam Technology and Material Modification of Ministry of Education College of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China INFN Laboratori Nazionali di LegnaroI-35020 LegnaroItaly INFN Sezione di NapoliI-80126 NapoliItaly Dipartimento di Farmacia Universitàdi Napoli"Federico II"I-80131 NapoliItaly Department of Natural and Mathematical Sciences Faculty of EngineeringTarsus University33480 MersinTurkiye Physics Division Argonne National LaboratoryLemont-ILUSA Departamento de Matemaética Física e Computaç˜ao Universidade do Estado do Rio de JaneiroFaculdade de Tecnologia27537-000ResendeRio de JaneiroBrazil Department of Physics Sivas Cumhuriyet UniversitySivasTurkey Instituto de Física Universidade Federal do Rio de JaneiroCP 6852821941-972Rio de JaneiroBrazil

The complete and incomplete fusion cross sections for ^(6)Li+^(209)Bi were measured using the in-beamγ-ray method around the coulomb *** cross sections of(deuteron captured)incomplete fusion(IcF)products were re-quantified experimentally for this reaction *** results reveal that the IcF cross section is equivalent to that of complete fusion(cF)above the coulomb barrier and dominant near or below the coulomb barrier.A theoretical calculation based on the continuum discretized coupled channel(cDcc)method was performed for the aforementioned cF and IcF cross sections;the result is consistent with the *** universal fusion function(UFF)was also compared with the measured cF cross section for different barrier parameters,demonstrating that the cF suppression factor is significantly influenced by the choice of potential,which can reflect both dynamic and static effects of breakup on the fusion process.

关键词： cross section incomplete fusion suppression factor weakly bound nuclei

Detection of false data injection attacks on power systems using graph edge-conditioned convolutional networks

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Protection and control of Modern Power Systems 2023年第2期8卷 1-12页

作者： Bairen chen q.h.Wu Mengshi Li Kaishun Xiahou School of Electric Power engineering South China University of TechnologyGuangzhou 510641China

State estimation plays a vital role in the stable operation of modern power systems,but it is vulnerable to cyber *** data injection attacks(FDIA),one of the most common cyber attacks,can tamper with measure-ment data and bypass the bad data detection(BDD)mechanism,leading to incorrect results of power system state estimation(PSSE).This paper presents a detection framework of FDIA for PSSE based on graph edge-conditioned convolutional networks(GEccN),which use topology information,node features and edge *** deep graph architecture,the correlation of sample data is effectively mined to establish the mapping relationship between the estimated values of measurements and the actual states of power *** addition,the edge-conditioned convolution operation allows processing data sets with different graph *** studies are undertaken on the IEEE 14-bus system under different attack intensities and degrees to evaluate the performance of *** results show that GEccN has better detection performance than convolutional neural networks,deep neural net-works and support vector ***,the satisfactory detection performance obtained with the data sets of the IEEE 14-bus,30-bus and 118-bus systems verifies the effective scalability of GEccN.

关键词： Power system state estimation(PSSE) Bad data detection(BDD) False data injection attacks(FDIA) Graph edge-conditioned convolutional networks(GEccN)