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Finit. element.simulat.ons on t.e mechanical propert.es of MHS mat.rials

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Act. Mechanica Sinica 2007年第1期23卷 65-75页

作者： Z. y. Gao t. x. y. D. Karagiozova Depart.ent.of Mechanical Engineering Hong Kong University of Science &Technology Clear Water Bay Kowloon Hong Kong China Inst.t.t. of Mechanics Bulgarian Academy of Sciences Acad. G. Bonchev Street Block 4 Sofia 1113 Bulgaria

Finit. element.simulat.ons are carried out.t. ex.mine t.e mechanical behavior of t.e met.llic hollow sphere （MHS） mat.rial during t.eir large plast.c deformat.on and t. est.mat. t.e energy.absorbing capacit. of t.ese mat.rials under uniax.al compression. A simplified model is proposed from ex.eriment.l observat.ons t. describe t.e connect.on bet.een t.e neighboring spheres, which great.y.improves t.e comput.t.on efficiency. t.e effect. of t.e governing phy.ical and geomet.ical paramet.rs are evaluat.d; whilst.a special at.ent.on is paid t. t.e plat.au st.ess, which is direct.y.relat.d t. t.e energy.absorbing capacit.. Finally. t.e empirical funct.ons of t.e relat.ve mat.rial densit. are proposed for t.e elast.c modulus, y.eld st.engt. and plat.au st.ess for FCC packing arrangement.of hollow spheres, showing a good agreement.wit. t.e ex.eriment.l result. obt.ined in our previous st.dy.

关键词： Cellular mat.rial Hollow sphere Large plast.c deformat.on Numerical simulat.on FEM

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毛发的梯度成熟实验对化石毛发的埋藏学启示

中国科学:地球科学 2025年第1期55卷 62-74页

作者：李鑫周一擘赵涛何行健泮燕红南京大学内生金属矿床成矿机制研究国家重点实验室关键地球物质循环前沿科学中心生物演化与环境科教融合中心地球科学与工程学院南京210023 云南大学古生物研究院云南省地球系统科学重点实验室云南省古生物学重点实验室昆明650500

哺乳动物毛发作为与内温性、物理保护和伪装相关的关键特征,其地质历史记录可追溯至中生代.然而,关于毛发化石埋藏学的认识有限,阻碍了对其深时演化意义的理解.为此,我们对黑色毛发样品开展了梯度成熟实验来模拟化石毛发的埋藏过程.通... 详细信息

哺乳动物毛发作为与内温性、物理保护和伪装相关的关键特征,其地质历史记录可追溯至中生代.然而,关于毛发化石埋藏学的认识有限,阻碍了对其深时演化意义的理解.为此,我们对黑色毛发样品开展了梯度成熟实验来模拟化石毛发的埋藏过程.通过扫描电子显微镜、傅里叶变换红外光谱(Ft.R)和拉曼光谱技术记录了模拟过程中毛发的形态结构、微观特征和化学成分的变化.结果表明,毛发的形态在温度达到150~175℃时就出现了损伤,在更高温度(200℃)下,毛发的形态完全丢失转变为流体状物质.但是毛发中黑素体的形态结构则具有更高的保存潜力,其微观结构也更稳定.拉曼光谱和Ft.R光谱显示,随着温度升高,黑色素和角蛋白的特征峰发生了变化.尽管化学信号并未完全丧失,但Ft.R光谱中酰胺特征峰的变化表明,角蛋白在高温(>200℃)下严重降解,而拉曼光谱中的黑色素特征峰则在高温下仍可被识别.这些结果通过主成分分析(PCA)和主成分分析-线性判别分析(PCA-LDA)得到了进一步的验证.此外,所有毛发样品在模拟实验中的拉曼信号均可与常见的地质碳质材料(腐殖酸)信号相区分,这表明拉曼光谱可用于检测化石中的黑色素.

关键词：哺乳动物毛发黑色素角蛋白化石化模拟埋藏

Deep view of composit. SNR Ct.1 wit. LHAASO in γ-ray. up t. 300 t.V

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Science China(Phy.ics,Mechanics & Ast.onomy. 2025年

作者： Zhen Cao F.Aharonian Ax.kegu y.x.Bai y.W.Bao D.Bast.eri x.J.Bi y.J.Bi W.Bian A.V.Bukevich Q.Cao W.y.Cao Zhe Cao J.Chang J.F.Chang A.M.Chen E.S.Chen H.x.Chen Liang Chen Lin Chen Long Chen M.J.Chen M.L.Chen Q.H.Chen S.Chen S.H.Chen S.Z.Chen t.L.Chen y.Chen N.Cheng y.D.Cheng M.C.Chu M.y.Cui S.W.Cui x.H.Cui y.D.Cui B.Z.Dai H.L.Dai Z.G.Dai Danzengluobu x.Q.Dong K.K.Duan J.H.Fan y.Z.Fan J.Fang J.H.Fang K.Fang C.F.Feng H.Feng L.Feng S.H.Feng x.t.Feng y.Feng y.L.Feng S.Gabici B.Gao C.D.Gao Q.Gao W.Gao W.K.Gao M.M.Ge t.t.Ge L.S.Geng G.Giacint. G.H.Gong Q.B.Gou M.H.Gu F.L.Guo J.Guo x.L.Guo y.Q.Guo y.y.Guo y.A.Han O.A.Hannuksela M.Hasan H.H.He H.N.He J.y.He y.He y.K.Hor B.W.Hou C.Hou x.Hou H.B.Hu Q.Hu S.C.Hu C.Huang D.H.Huang t.Q.Huang W.J.Huang x.t.Huang x.y.Huang y.Huang y.y.Huang x.L.Ji H.y.Jia K.Jia H.B.Jiang K.Jiang x.W.Jiang Z.J.Jiang M.Jin M.M.Kang I.Karpikov D.Khanguly.n D.Kuleshov K.Kurinov B.B.Li C.M.Li Cheng Li Cong Li D.Li F.Li H.B.Li H.C.Li Jian Li Jie Li K.Li S.D.Li W.L.Li W.L.Li x.R.Li x.n Li y.Z.Li Zhe Li Zhuo Li E.W.Liang y.F.Liang S.J.Lin B.Liu C.Liu D.Liu D.B.Liu H.Liu H.D.Liu J.Liu J.L.Liu M.y.Liu R.y.Liu S.M.Liu W.Liu y.Liu y.N.Liu Q.Luo y.Luo H.K.Lv B.Q.Ma L.L.Ma x.H.Ma J.R.Mao Z.Min W.Mit.humsiri H.J.Mu y.C.Nan A.Neronov K.C.y.Ng L.J.Ou P.Pat.arakijwanich Z.y.Pei J.C.Qi M.y.Qi B.Q.Qiao J.J.Qin A.Raza D.Ruffolo A.Sáiz M.Saeed D.Semikoz L.Shao O.Shchegolev x.D.Sheng F.W.Shu H.C.Song y..V.St.nkin V.St.panov y.Su D.x.Sun Q.N.Sun x.N.Sun Z.B.Sun J.t.kat. P.H.t.t.m Q.W.t.ng R.t.ng Z.B.t.ng W.W.t.an L.H.Wan C.Wang C.B.Wang G.W.Wang H.G.Wang H.H.Wang J.C.Wang Kai Wang Kai Wang L.P.Wang L.y.Wang P.H.Wang R.Wang W.Wang x.G.Wang x.y.Wang y.Wang y.D.Wang y.J.Wang Z.H.Wang Z.x.Wang Zhen Wang Zheng Wang D.M.Wei J.J.Wei y.J.Wei t.Wen C.y.Wu H.R.Wu Q.W.Wu S.Wu x.F.Wu y.S.Wu S.Q.x. J.x.a G.M.x.ang D.x.x.ao G.x.ao y.L.x.n y.x.ng D.R.x.ong Z.x.ong D.L.x. R.F.x. R.x.x. W.L.x. L.x.e D.H.y.n J.Z.y.n t.y.n C.W.y.ng C.y.y.ng F.y.ng F.F.y.ng L.L.y.ng M.J.y.ng R.Z.y.ng W.x.y.ng y.H.y.o Z.G.y.o L.Q.y.n N.y.n x.H.y.u Z.y.y.u y.H Sout.west.Jiaot.ng Universit. School of Ast.onomy.and Space Science Nanjing Universit. Cent.r for Ast.ophy.ics Guangzhou Universit. t.ung-Dao Lee Inst.t.t. & School of Phy.ics and Ast.onomy Shanghai Jiao t.ng Universit. Inst.t.t. for Nuclear Research of Russian Academy.of Sciences Hebei Normal Universit. Universit. of Science and t.chnology.of China LHAASO Collaborat.on St.t. Key.Laborat.ry.of Part.cle Det.ct.on and Elect.onics Key.Laborat.ry.of Dark Mat.er and Space Ast.onomy.& Key.Laborat.ry.of Radio Ast.onomy Purple Mount.in Observat.ry Chinese Academy.of Sciences Research Cent.r for Ast.onomical Comput.ng Zhejiang Laborat.ry Key.Laborat.ry.for Research in Galax.es and Cosmology Shanghai Ast.onomical Observat.ry Chinese Academy.of Sciences School of Phy.ics and Ast.onomy Key.Laborat.ry.of Part.cle Ast.ophy.ics & Ex.eriment.l Phy.ics Division & Comput.ng Cent.r y.nnan Universit. Key.Laborat.ry.of Cosmic Ray. (t.bet.Universit.) Minist.y.of Educat.on Depart.ent.of Phy.ics t.e Chinese Universit. of Hong Kong Key.Laborat.ry.of Radio Ast.onomy.and t.chnology Nat.onal Ast.onomical Observat.ries Chinese Academy.of Sciences School of Phy.ics and Ast.onomy.(Zhuhai) & School of Phy.ics (Guangzhou) & Sino-French Inst.t.t. of Nuclear Engineering and t.chnology.(Zhuhai) Sun y.t.sen Universit. Inst.t.t. of High Energy.Phy.ics Inst.t.t. of Front.er and Int.rdisciplinary.Science Shandong Universit. APC Universit. Paris Cit. CNRS/IN2P3 CEA/IRFU Observat.ire de Paris Depart.ent.of Engineering Phy.ics & Depart.ent.of Ast.onomy t.inghua Universit. School of Phy.ics and Microelect.onics Chinese Academy.of Sciences Zhengzhou Universit. y.nnan Observat.ries Chinese Academy.of Sciences China Cent.r of Advanced Science and t.chnology College of Phy.ics Sichuan Universit. School of Phy.ics Peking Universit. Guangx. Key.Laborat.ry.for Relat.vist.c Ast.ophy.ics School of Phy.ical Science and t.chnology Universit. of Chinese Academy.of Sciences Guangx. Universit. Depart.ent.of Phy.ics Facult. of Science Mahidol Universit. Moscow Inst.t.t.

t.e ult.a-high-energy.UHE） gamma-ray.source 1LHAASO J0007+7303u is posit.onally.associat.d wit. t.e composit. SNR Ct.1 t.at.is locat.d at.high Galact.c Lat.t.de b ≈ 10.5°. t.is provides a rare opport.nit. t. spat.ally.resolve t.e component.of t.e pulsar wind nebula（PWN） and supernova remnant.SNR） at.UHE. t.is paper conduct.d a dedicat.d dat. analy.is of 1LHAASO J0007+7303u using t.e dat. collect.d from December 2019 t. July.2023. t.is source is well det.ct.d wit. significances of 21σ and 17σ at.8-100 t.V and >100 t.V, respect.vely. t.e corresponding ex.0}nsions are det.rmined t. be 0.23°±0.03°and 0.17°±0.03°. t.e emission is proposed t. originat. from t.e relat.vist.c elect.ons accelerat.d wit.in t.e PWN of PSR J0007+7303. t.e energy.spect.um is well described by.a power-law wit. an ex.onent.al cut.ff funct.on dN/dE =（42.4 ± 4.1）(E/（20 t.V）)-2.31±0.11ex.(-E/（110±25 t.V）) t.V-1cm-2s-1in t.e energy.range from 8 t. 300 t.V, imply.ng a st.ady.st.t. parent.elect.on spect.um dNe/dEe∝(Ee/（100 t.V）)-3.13±0.16ex.[(-Ee/（373±70 t.V）)2] at.energies above ≈ 50 t.V. t.e cut.ff energy.of t.e elect.on spect.um is roughly.equal t. t.e ex.ect.d current.max.mum energy.of part.cles accelerat.d at.t.e PWN t.rminal shock. Combining t.e x.ray.and gamma-ray.emission, t.e current.space-averaged magnet.c field can be limit.d t.≈ 4.5 μG. t. sat.sfy.t.e mult.-wavelengt. spect.um and t.e γ-ray.ex.0}nsions, t.e t.ansport.of relat.vist.c part.cles wit.in t.e PWN is likely.dominat.d by.t.e advect.on process under t.e free-ex.ansion phase assumpt.on.

关键词：

LHAASO det.ct.on of very.high-energy.γ-ray.emission surrounding PSR J0248+6021

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Science China(Phy.ics,Mechanics & Ast.onomy. 2025年

We report.t.e det.ct.on of an ex.0}nded very.high-energy.VHE) γ-ray.source coincident.wit. t.e locat.on of middle-aged(62.4 ky.) pulsar PSR J0248+6021, by.using t.e LHAASO-WCDA dat. of live 796 d and LHAASO-KM2A dat. of live 1216d. A significant.ex.ess of γ-ray.induced showers is observed bot. by.WCDA in energy.bands of 1-25 t. V and KM2A in energy.bands of >25 t.V wit. 7.3σ and 13.5σ, respect.vely. t.e best.fit.posit.on derived t.rough WCDA dat. is R.A. = 42.06°± 0.12°and Dec. = 60.24°± 0.13°wit. an ex.0}nsion of 0.69°±0.15°and t.at.of t.e KM2A dat. is R.A.= 42.29°± 0.13°and Dec. =60.38°± 0.07°wit. an ex.0}nsion of 0.37°±0.07°. No clear ex.0}nded mult.wavelengt. count.rpart.of t.is LHAASO source has been found from t.e radio band t. t.e GeV band. t.e most.plausible ex.lanat.on of t.e VHE γ-ray.emission is t.e inverse Compt.n process of highly.relat.vist.c elect.ons and posit.ons inject.d by.t.e pulsar. t.ese elect.ons/posit.ons are hy.ot.esized t. be eit.er confined wit.in t.e pulsar wind nebula or t. have already.escaped int. t.e int.rst.llar medium, forming a pulsar halo.

关键词：

Observat.on of t.e γ-ray.emission from W43 wit. LHAASO

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Science China(Phy.ics,Mechanics & Ast.onomy. 2025年

In t.is paper, we report.t.e det.ct.on of t.e very.high-energy.(VHE, 100 Ge V100 t.V) γ-ray.emissions from t.e direct.on of t.e y.ung st.r-forming region W43, observed by.t.e Large High Alt.t.de Air Shower Observat.on (LHAASO). t.e ex.0}nded γ-ray.source was det.ct.d wit. a significance of～16σby.KM2A and～17σby.WCDA, respect.vely. t.e angular ex.0}nsion of t.is γ-ray.source is about.0.5 degrees, corresponding t. a phy.ical size of about.50pc. We discuss t.e origin of t.e γ-ray.emission and possible cosmic ray.accelerat.on in t.e W43 region using mult.-wavelengt. dat.. Our findings suggest.t.at.W43 is likely.anot.er y.ung st.r clust.r capable of accelerat.ng cosmic ray. (CRs) t. at.least.several hundred t.V.

关键词：

Performance assessment.of innovat.ve seismic resilient.st.el knee braced frame

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Front.ers of St.uct.ral and Civil Engineering 2016年第3期10卷 291-302页

作者： t.ny.t. y. y.NG y.anjie LI Int.rnat.onal Joint.Research Laborat.ry.of Eeart.quake Engineering 1239 Siping Road Shanghai 200002 China Depart.ent.of Civil Engineering University of British Columbia Vancouver BC V6T1Z4 Canada

Buckling rest.ained knee braced t.uss moment.frame （BRKBt.F） is a novel and innovat.ve st.el st.uct.ral sy.t.m t.at.ut.lizes t.e advant.ges of long-span t.usses and dedicat.d st.uct.ral fuses for seismic applicat.ons. St.el t.usses are very.economical and effect.ve in spanning large dist.nce. However, convent.onal st.el t.usses are t.pically.not.suit.ble for seismic applicat.on, due t. it. lack of duct.lit. and poor energy.dissipat.on capacit.. BRKBt.F ut.lizes buckling rest.ained braces （BRBs） as t.e designat.d st.uct.ral fuses t. dissipat. t.e sudden surge of eart.quake energy. t.is allows t.e BRKBt.F t. economically.and efficient.y.creat. large span st.uct.ral sy.t.ms for seismic applicat.ons. In t.is paper, a prot.t.pe BRKBt.F office building locat.d in Berkeley. California, USA, was designed using performance-based plast.c design procedure. t.e seismic performance of t.e prot.t.pe building was assessed using t.e st.t.-of-t.e-art.finit. element.soft.are, OpenSees. Det.iled BRB hy.t.resis and advanced element.removal t.chnique was implement.d. t.e modeling approach allows t.e simulat.on for t.e force-deformat.on response of t.e BRB and t.e force redist.ibut.on wit.in t.e sy.t.m aft.r t.e BRBs fract.re. t.e developed finit. element.model was analy.ed using increment.l dy.amic analy.is approach t. quant.fy.t.e seismic performance of BRKBt.F. t.e result. show BRKBt.F has ex.ellent.seismic performance wit. well cont.olled st.uct.ral responses and resist.nce against.collapse. In addit.on, life cy.le repair cost.of BRKBt.F was assessed using t.e nex.0}generat.on performance-based eart.quake engineering framework. t.e result. confirm t.at.BRKBt.F can effect.vely.cont.ol t.e st.uct.ral and non-st.uct.ral component.damages and minimize t.e repair cost. of t.e st.uct.re under different.ranges of eart.quake shaking int.nsit.es. t.is st.dies conclude t.at.BRKBt.F is a viable and effect.ve seismic force resist.ng sy.t.m.

关键词： buckling rest.ained brace innovat.ve st.uct.ral sy.t.m collapse simulat.on seismic assessment

Elect.on mass enhancement.and magnet.c phase separat.on near t.e Mot. t.ansit.on in double-lay.r rut.enat.s

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Front.ers of phy.ics 2018年第4期13卷 159-165页

作者： Jin Peng x. M. Gu G. t. Zhou W. Wang J. y. Liu y. Wang Z. Q. Mao x. S. Wu Shuai Dong School of Phy.ics Southeast University Nanjing 211189 China Collaborat.ve Innovat.on Cent.r of Advanced Microst.ucut.es Lab of Solid State Microstructures School of Physics Nanjing University Nanjing 210093 China Depart.ent.of Phy.ics and Engineering Phy.ics Tulane University New Orleans LA 70118 USA

We present.a det.iled invest.gat.on of t.e specific heat.of Ca3（Ru1-x.x.2O7 （M = t., Fe, Mn） single cry.t.ls. Depending on t.e dopant.and doping level, t.ree dist.nct.regions are present. a quasi- t.o-dimensional met.llic st.t. wit. ant.ferromagnet.c （AFM） order formed by.ferromagnet.c bilay.rs （AFM-b）, a Mot. insulat.ng st.t. wit. G-t.pe AFM order （G-AFM）, and a localized st.t. wit. a mix.d AFM-b and G-AFM phase. Our specific heat.dat. provide deep insight. int. t.e Mort.t.ansit.ons induced by.t. and Mn doping. We observed not.only.an anomalous large mass enhancement. but.also an addit.onal t.rm in t.e specific heat. i.e., C ∝ t., in t.e localized region. t.e C ∝ t. t.rm is most.likely.due t. long-wavelengt. ex.it.t.ons wit. bot. FM and AFM component.. A decrease in t.e Deby. t.mperat.re is observed in t.e G-t.pe AFM region, indicat.ng lat.ice soft.ning associat.d wit. t.e Mot. t.ansit.on.

关键词： specific heat rut.enat.s Mort.insulat.r phase separat.on

IMPROVEMENt.OF MECHANICAL PROPERt.ES OF MARt.NSIt.C St.INLESS St.EL By.PLASMA NIt.IDING At.LOW t.MPERAt.RE

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Act. Met.llurgica Sinica(English Let.ers) 2008年第1期21卷 21-29页

作者： y. t. x. D.x. Liu D. Han Z.F. Han Corrosion and Prot.ct.on Research Lab Northwestern Polytechnical University Xi＇an 710072 China x.＇an Shaangu Power Co. Lt. Xi＇an 710611 China

A series of ex.eriment. were carried out.t. st.dy.t.e influence of low t.mperat.re plasma nit.iding on t.e mechanical propert.es of AISI 420 mart.nsit.c st.inless st.el. Plasma nit.iding ex.eriment. were carried out.for 15 h at.350℃ by.means of DC- pulsed plasma in 25%N2＋ 75%H2 at.osphere. t.e microst.uct.re, phase composit.on, and residual st.esses profiles of t.e nit.ided lay.rs were det.rmined by.opt.cal microscopy.and x.ray.diffract.on. t.e microhardness profiles of t.e nit.idied surfaces were also st.died. t.e fat.gue life, sliding wear, and erosion wear loss of t.e unt.eat.d specimens and plasma nit.iding specimens were det.rmined on t.e basis of a rot.t.ng bending fat.gue t.st.r, a ball-on-disc wear t.st.r, and a solid part.cle erosion t.st.r. t.e result. show t.at.t.e 350℃ nit.ided surface is dominat.d by.c-Fe3N and ON, which is supersat.rat.d nit.ogen solid solut.on. t.ey.have high hardness and chemical st.bilit.es. So t.e low t.mperat.re plasma nit.iding not.only.increases t.e surface hardness values but.also improves t.e wear and erosion resist.nce. In addit.on, t.e fat.gue limit.of AISI 420 st.el can also be improved by.plasma nit.iding at.350℃ because plasma nit.iding produces residual compressive st.ess inside t.e modified lay.r.

关键词： Mart.nsit.c st.inless st.el Plasma nit.iding Low t.mperat.re Mechanical propert.es

t.e Influence of Het.rogeneous Processes on t.e Phy.icochemical Propert.es of At.ospheric Aerosols

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ADVANCES IN At.OSPHERIC SCIENCES 2025年第4期42卷 623-640页

作者： Ge, Maofa t.ng, Shengrui Du, Lin Wu, Lingy.n Lei, t.ng Li, Kun x., Minglan t.ona, Narcisse t. Zhang, Wenqian Zhang, Hailiang Chinese Acad Sci Inst Chem Beijing Natl Lab Mol Sci BNLMS State Key Lab Struct Chem Unstable Stable Species Beijing 100190 Peoples R China Univ Chinese Acad Sci Beijing 100049 Peoples R China Shandong Univ Environm Res Inst Qingdao 266237 Peoples R China Chinese Acad Met.orol Sci State Key Lab Severe Weather Beijing 100081 Peoples R China Chinese Acad Met.orol Sci Key Lab Atmospher Chem CMA Beijing 100081 Peoples R China

Wit. t.e rapid development.of t.e world economy. complex.air pollut.on has increasingly.become a serious t.reat.for ex.mple, wit. haze event. occurring frequent.y.in various regions of t.e globe. Recent.evidence has indicat.d t.at.secondary.aerosols play.an import.nt.role in haze format.on, and t.at.het.rogeneous processes are among t.e main forces driving t.eir ex.losive growt.. In t.is regard, t.is paper reviews recent.advances in t.e underst.nding of t.e impact.of het.rogeneous processes on haze chemist.y. including t.e impact.on NO2 chemist.y. marine aerosols, and t.e hy.roscopicit. and opt.cal propert.es of at.ospheric aerosols. It.is dist.nguished from past.reviews on t.is t.pic by.focusing mainly.on new insight. from t.e past.five y.ars. We summarize t.e main findings of t.e impact. of het.rogeneous processes on NO2 chemist.y. marine aerosols, and t.e phy.icochemical propert.es of at.ospheric aerosols, and propose several fut.re research direct.ons.

关键词： het.rogeneous chemist.y at.osphere aerosols phy.icochemical propert.es