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A Statistical An.lysis of Poin.-lik. Sources in.the Chan.ra Galactic Cen.er Survey

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Chin.se Journ.l of Astron.my an. Astrophysics 2007年第1期7卷 81-90页

作者： J. E Wu S. n. Zhan. F.J. Lu Y. k. Jin Departmen. of Physics an. Cen.er for Astrophysics Tsinghua University Beijing 100084 k.y Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy ofSciences Beijing 100049 Departmen. of En.in.erin. Physics an. Cen.er for Astrophysics Tsinghua University Beijing 100084

The Chan.ra Galactic Cen.er Survey detected -800 X-ray poin.-lik. sources in.the 2°× 0.8° sk. region.aroun. the Galactic Cen.er. We study the spatial an. lumin.sity distribution. of these sources accordin. to their spectral properties. Fourteen.bright sources detected are used to fit join.ly an.absorbed power-law model, from which the power-law photon.in.ex is determin.d to be -2.5. Assumin. that all other sources have the same power-law form, the relation.between.hardn.ss ratio an. HI column.den.ity n. is used to estimate the n. values for all sources. Mon.e Carlo simulation. show that these sources are more lik.ly con.en.rated in.the Galactic cen.er region. rather than.distributed throughout the Galactic disk. We also fin. that the lumin.sities of the sources are positively correlated with their HI column.den.ities, i.e., a more lumin.us source has a higher HI column.den.ity. From this relation. we suggest that the X-ray lumin.sity comes from the in.eraction.between.an.isolated old n.utron.star an. in.erstellar medium （main.y den.e molecular clouds）. Usin. the stan.ard Bon.i accretion.theory an. the statistical in.ormation.of molecular clouds in.the Galactic cen.er, we con.irm this positive correlation.an. calculate the lumin.sity ran.e in.this scen.rio, which is con.isten. with the observation.（10^32 - 10^35 erg s^-1）.

关键词： methods data an.lysis-Galaxy cen.er-X-ray stars

TRISO fuel volume fraction.an. homogen.ity:a n.n.estructive characterization

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n.clear Scien.e an. Techn.ques 2019年第3期30卷 46-52页

作者： k. V. Vrin.a Devi J. n. Dubey Jyoti Gupta I. H. Shaik. Radiometallurgy Division Bhabha Atomic Research CentreMumbaiIndia

A n.w n.n.estructive method to estimate the volume fraction.an. homogen.ity of tristructural isotropic(TRISO)-coated fuel particles in.fuel compacts design.d for high-temperature reactors has been.developed usin. image an.lysis of con.en.ion.l X-radiographs. The method is demon.trated on.surrogate fuel compacts con.ain.n. TRISO-coated particles with k.rn.ls made of zircon.um dioxide. The methodology in.orporates a correction.for superimposed images of TRISO particles such that a sin.le X-ray image obtain.d in.an. on. ran.om orien.ation.is sufficien. to characterize the fuel compact in.terms of volume fraction.an. homogen.ity. The method is based on.the virtual segregation.of images of each particle in.ide the compact with the aid of a calibration.stan.ard.

关键词： TRISO Volume fraction Homogen.ity Radiography

In.ibition.of retroviral Gag assembly by n.n.silen.in. miRn.s promotes autophagic viral degradation

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Protein.& Cell 2018年第7期9卷 640-651页

作者： n. Qu Zhao Ma Men.rao Zhan. Muaz n. Rushdi Christopher J. k.ueger An.on. k. Chen Departmen. of Biomedical En.in.erin. College of Engineering Peking University Beijing 100871 China Wallace H Coulter Departmen. of Biomedical-En.in.erin. Georgia Institute of Technology Atlanta GA 30332 USA

We recen.ly reported an.un.on.en.ion.l mechan.sm by which miRn.s in.ibit HIV-1 viral production. This occurs when.miRn.s bin. n.n.pecifically to the viral structural protein.Gag, in.erferin. with viral Rn.-medi- ated Gag assembly at the plasma membran.. Con.e- quen.ly, misassembled viral complexes are redirected in.o the en.ocytic pathway where they are delivered to lysosomes for degradation. In.this study, we demon. strate that autophagy is a critical mediator of the viral degradation.pathway an. that this pathway is n.t HIV-1 specific. Misassembled viral complexes were foun. to colocalize exten.ively with LC3 an. p62 in.late en.o- somesllysosomes, demon.tratin. a con.ergen.e of autophagy with fun.tion.l degradative compartmen.s. k.0}ck.n. down.autophagosome formation.machin.ries reduced this con.ergen.e, while treatmen. with autop- hagy-in.ucer rapamycin.en.an.ed the con.ergen.e. Furthermore, similar autophagy-depen.en. n.n.pecific miRn. in.ibition.of murin. leuk.mia virus （MLV） assembly was shown. Overall, these results reveal autophagy as a crucial regulator of the retroviral degradation.pathway in.host cells in.tiated by n.n. specific miRn.-Gag in.eraction.. These fin.in.s could have sign.fican. implication. for un.erstan.in. how cells may regulate retroviral complex assembly by miRn. expression.an. autophagy, an. raise the possi- bility that similar regulation. can.occur in.other biolog- ical con.exts.

关键词： microRn. Gag protein autophagy

Distin.t Electrical an. Mechan.cal Respon.es of a Cu-10Fe Composite Prepared by Hot-Pressed Sin.erin. an. Post Treatmen.

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Acta Metallurgica Sin.ca(En.lish Letters) 2024年第2期37卷 255-265页

作者： X.Y.Yue S.Y.Pen. X.Zhan. C.n.He Y.Z.Tian k.y Laboratory for An.sotropy an. Texture of Materials(Min.stry of Education. School of Materials Science and EngineeringNortheastern UniversityShenyang110819China School of Materials Scien.e an. En.in.erin. an. Tian.in.k.y Laboratory of Composite an. Fun.tion.l Materials Tianjin UniversityTianjin300350China Research Cen.re for Metallic Wires Northeastern UniversityShenyang110819China

A Cu-10wt%Fe composite was prepared through hot-pressed sin.erin.,an. the material was subsequen.ly solution.*** hot-pressed sin.ered an. solution.treated materials were rolled an. *** precipitation.behavior an. performan.e chan.es were systematically studied by usin. scan.in. electron.microscopy an. tran.mission.electron.*** con.rast to the hot-pressed sin.ered specimen.the solution.treatmen. sign.fican.ly affects the thermal stability an. properties of the Cu-10wt%Fe *** Cu-10wt%Fe composite was prepared after solid solution.cold rollin. an. agin. at 773 k.for 1 h,an. it obtain.d excellen. ten.ile stren.th of 494 MPa,un.form elon.ation.of 16.3%,electrical con.uctivity of 51.1%IACS an. soften.n. temperature of 838 *** for the distin.t differen.e in.thermal stability an. properties between.hot-pressed sin.ered an. solution.treated specimen. were *** fin.in.s provide a theoretical basis for design.n. high-performan.e Cu-based in.situ composites by post treatmen..

关键词： Cu-Fe composite Hot-pressed sin.erin. Thermal stability Stren.th Electrical con.uctivity

Determin.tion.of k.n.tic parameters from calorimetric study of solid state reaction. in.7150 Al-Zn.Mg alloy

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Tran.action. of n.n.errous Metals Society of Chin. 2011年第6期21卷 1199-1209页

作者： k. S. GHOSH n. GAO Departmen. of Metallurgical an. Materials En.in.erin. National Institute of Technology Durgapur 713 209 India Materials Research Group School of Engineering Science University of Southampton Southampton SO 17 1B J UK

Differen.ial scan.in. calorimetric （DSC） study was carried out at differen. heatin. rates to examin. the solid state reaction. in.a 7150 A1-Zn.Mg alloy in.water-quen.hed （WQ） state, n.turally an. artificially aged tempers. The exothermic an. en.othermic peak. of the thermograms in.icatin. the solid state reaction.sequen.e were iden.ified. The shift of peak.temperatures to higher temperatures with in.reasin. heatin. rates suggests that the solid state reaction. are thermally activated an. k.n.tically con.rolled. The artificial agin. behaviour of the alloy was assessed by measurin. the variation. of hardn.ss with agin. time. The fraction.of tran.formation.（Y）, the rate of tran.formation.（dY/dt）, the tran.formation.fun.tion.lY）, an. the k.n.tic parameters such as activation.en.rgy （Q） an. frequen.y factor （k.） of all the solid state reaction. in.the alloy were determin.d by an.lyzin. the DSC data, i.e. heat flow in.olved with the correspon.in. DSC peak.. It was foun. that the k.n.tic parameters of the solid state reaction. are in.good agreemen. with the published data.

关键词： 7150 Al-Zn.Mg alloy DSC agin. behaviour activation.en.rgy tran.formation.fun.tion

Crystal structure an. lumin.scen.e dyn.mics of highly pure LiM(PO_(3))_(3):Eu^(3+)(M=Sr,Ca) red phosphors for white light emittin. diodes

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Journ.l of Rare Earths 2024年第8期42卷 1470-1478,I0002页

作者： Payal k.ajuria M.Man.as A.k.Bedyal An.ush Vij H.C.Swart Vin.y k.mar Departmen. of Physics an. Astron.mical Scien.es Central University of JammuRahy-Suchani.Samba1143J&KIndia Departmen. of Physics School of SciencesCluster University of JammuCanal RoadJammu180001India Departmen. of Physics University of Petroleum and Energy StudiesDehradunUttarakhand248007India Departmen. of Physics University of the Free StateP.O.Box 339BloemfonteinZA 9300South Africa

Highly pure red phosphors LiM(PO_(3))_(3):Eu^(3+)(M=Sr,Ca) doped with Eu^(3+)(1 mol%) were syn.hesized via solution.combustion.method an. their crystal structure an. lumin.scen.e dyn.mics were studied to explore its suitability in.white light emittin. *** Rietveld refin.men. an.lysis of the powder Xray diffraction.pattern. reveals that the phosphors belon. to the pure triclin.c phase of LiSr(PO_(3))_(3) an. LiCa(PO_(3)) with space group P-1(2).The scan.in. electron.microscopy images showed the agglomerated *** photolumin.scen.e emission.spectra un.er 393 n. show an.oran.e ban. at 594 n. an. a red ban. at 613 n. ascribed to ^(5)D_(0)→^(7)F_(1).^(5)D_(0)→^(7)F_(2) tran.ition. of Eu^(3+)ion.in.both the ***,the spectroscopic properties such as lumin.scen.e behaviour,an. Stark.splittin. were used to examin. the symmetry of Eu^(3+)ion. in.LiM(PO_(3))_(3):Es^(3+)(M=Sr,Ca) phosphors in.terms of distortion.in.uced upon.*** Stark.splittin. shows that the actual site symmetry for Eu^(3+)ion.was estimated to be D_(2) type for both *** photometric properties of LiCa(PO_(3))_(3):Eu^(3+)such as Commission.In.ern.tion.l de l'Eclairage coordin.tes(x=0.64,y=0.36) n.ar to the stan.ard on.(red),high color purity(95%) an. higher brightn.ss reveal that the phosphor has the capability of actin. as a red compon.n. in.n.UV white light emittin. diodes.

关键词： Photolumin.scen.e Phosphate WLEDs Stark.splittin. Rare earths

Catalytic role of Cu(I) species in.Cu_2O/CuI supported on.MWCn.s in.the oxidative amidation.of aryl aldehydes with 2-amin.pyridin.s

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Chin.se Journ.l of Catalysis 2015年第11期36卷 1825-1836页

作者： H. n. Hareesh k. U. Min.hitha n. n.garaju n. k.thyayin. 耆那大学纳米生物科学系新兴技术中心印度卡纳塔克邦格讷格布尔圣约学院及研究中心化学系催化研究实验室印度卡纳塔克邦班加罗尔

Cu2O an. Cul were supported on.multiwalled carbon.n.n.tubes （MWCn.s） usin. a wet impregn.- tion.method, an. the resultin. materials were fully characterized by powder X-ray diffraction. Fourier tran.form in.rared spectroscopy, scan.in. electron.microscopy with en.rgy dispersive X-ray spectroscopy, tran.mission.electron.microscopy, an. temperature-programmed desorption.with ammon.a an.lysis. The results of these experimen.s revealed that Cu2O an. CuI were deposited on.the MWCn.s in.the cubic an. γ phases, respectively. These results also showed that the Cu-con.ain.n. MWCn.s exhibited weak.to stron. electron.acceptin. （Lewis acidic） properties. The catalytic activities of these materials were studied for the syn.hesis of biologically sign.fican. n.（pyridin.2-yl）ben.amides via the oxidative amidation.of aryl aldehydes with 2-amin.pyridin.s. The yields of the products were in.the ran.e 50%-95% with 100% selectivity. n.tably, the CuI/MWCn. catalyst was much more effective than.the Cu2O/MWCn. catalyst with respect to the isolated yield of the product, although the latter of these two catalysts exhibited much better recyclability. A preferen.ial in.eraction.was observed between.the polar n.ture of the acid-activated MWCn.s an. the ion.c Cu2O compared with covalen. CuL The differen.es in.these in.eraction. had a sign.fican. impact on.the rate of the n.cleophilic attack.of the amin. group of 2-amin.pyridin. substrate on.the carbon.l group of the aryl aldehyde.

关键词： Cuprous oxide Cuprous iodide Multiwalled carbon.n.n.tube2-Amin.pyridin. Oxidative amidation

A Mitochon.rial Magn.sium Tran.porter Fun.tion. in.Arabidopsis Pollen.Developmen.

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Molecular Plan. 2008年第4期1卷 675-685页

作者： Le-Gon. Li Lubomir n. Sok.lov Yon.-Hua Yan. Don.-Pin. Li Julie Tin. Girdhar k. Pan.y Shen. Luan College of Life Scien.es Capital Normal University Beijing 100037 China Departmen. of Plan. an. Microbial Biology University of California Berkeley CA 94720 USA n.U-n.FU Join. In.titute for Plan. Molecular Biology College of life Sciences Nanjing University Nanjing 210093 China College of Life Scien.es Hunan Normal University Changsha 410006 China

Magn.sium is an.abun.an. divalen. cation.in.plan. cells an. plays a critical role in.man. physiological processes. We have previously described the iden.ification.of a 10-member Arabidopsis gen. family en.odin. putative magn.sium tran.port （MGT） protein.. Here, we report that a member of the MGT family, AtMGTS, fun.tion. as a dual-fun.tion.l Mg-tran.porter that operates in.a con.en.ration.depen.en. man.er, n.mely it serves as a Mg-importer at micromolar levels an. facilitates the efflux in.the millimolar ran.e. The AtMGT5 protein.is localized in.the mitochon.ria, suggestin. that AtMGTS mediates Mg-traffick.n. between.the cytosol an. mitochon.ria. The AtMGT5 gen. was exclusively expressed in.an.hers at early stages of flower developmen.. Examin.tion.of two in.epen.en. T-Dn. in.ertion.l mutan.s of AtMGT5 gen. demon.trated that AtMGT5 played an.essen.ial role for pollen.developmen. an. male fertility. This study suggests a critical role for Mg^2＋ tran.port between.cytosol an. mitochon.ria in.male gametogen.sis in.plan.s.

关键词： Mg^2+ -tran.porter pollen mitochon.ria Arabidopsis

The Soft X-ray Imager(SXI)on.the SMILE Mission

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Earth an. Plan.tary Physics 2024年第1期8卷 5-14页

作者： S.Sembay A.L.Alme D.Agn.lon.T.Arn.ld A.Beardmore A.Belén.Balado Margeli C.Bick.0}ll C.Bouldin.G.Bran.uardi-Raymon. T.Crawford J.P.Breuer T.Buggey G.Butcher R.Can.hal J.A.Carter A.Chen.y Y.Collado-Vega H.Con.or T.Crawford n.Eaton.C.Feldman.C.Forsyth T.Fran.zen.G.Galgóczi J.Garcia G.Y.Gen.v C.Gordillo H-P.Gröbelbauer M.Guedel Y.Guo M.Hailey D.Hall R.Hampson.J.Hasiba O.Hetherin.ton.A.Hollan. S-Y.Hsieh M.W.J.Hubbard H.Jeszen.zk. M.Jon.s T.k.n.edy k.koch-Mehrin.S.k.gl S.k.uck.r k.D.k.n.z C.Lak.n.G.Lak. O.Lylun. A.Martin.ale J.Miguel Mas Hesse R.n.k.mura k.Ok.avik.n.Østgaard H.Ottacher R.Otten.amer C.Pagan. S.Parson. P.Patel J.Pearson.G.Peik.rt F.S.Porter T.Poulian.is B.H.Qureshi W.Raab G.Ran.al A.M.Read n.M.M.Roque M.E.Rostad C.Run.iman.S.Sachdev A.Samson.v M.Soman.D.Sibeck.S.Smit J.Søn.ergaard R.Speight S.Stavlan. M.Steller Tian.an.Sun.J.Thorn.ill W.Thomas k.Ullalan. B.Walsh D.Walton.C.Wan. S.Yan. School of Physics an. Astron.my University of LeicesterLeicesterLE17RHUK Space Park.Leicester University of LeicesterLeicesterLE17RHUK Mullard Space Scien.e Laboratory University College LondonDorkingRH56NTUK Cen.re for Electron.c Imagin. Open UniversityMilton KeynesMK76 AAUK Birk.lan. Cen.re for Space Scien.e Department of Physics and TechnologyUniv.of BergenN-5007 BergenNorway Un.versity of Vien.a A-1010 ViennaAustria Space Research In.titute Austrian Academy of SciencesA-8042 GrazAustria n.tion.l In.titute of Aerospace Techn.logy MadridSpain ESTEC European Space Agency2201 AZ NoordwijkNetherlands State k.y Laboratory of Space Weather National Space Science CentreBeijing 100190China Un.versity of Applied Scien.es an. Arts n.rthwestern.Switzerlan. CH-5210 WindischSwitzerland k.egl Space GmbH CH-8157 DielsdorfSwitzerland Space Acoustics GmbH CH-8157 DielsdorfSwitzerland Zurich Un.versity of Applied Scien.es 8400 WinterhurSwitzerland Gen.v Solution. N-5172 LoddefjordNorway STM En.in.erin. N-5165 LaksevagNorway John.Hopk.n. Un.versity Applied Physics Laboratory MD 20723USA n.SA/Goddard Space Flight Cen.re MD 20771USA Cen.er for Space Physics Boston UniversityBostonMA 02215USA Departmen. of Theoretical Physics an. Astrophysics Masaryk University60177 BrnoCzech Republic In.titute of Physics E¨otvo¨s Lor´and University1053 BudapestHungary Aerospace In.ormation.Research In.titute Chinese Academy of SciencesBeijing 100045China Cen.ro de Astrobiologia(CAB) CSIC-INTAMadridSpain

The Soft X-ray Imager(SXI)is part of the scien.ific payload of the Solar win. Magn.tosphere Ion.sphere Lin. Explorer(SMILE)*** is a join. scien.e mission.between.the European.Space Agen.y(ESA)an. the Chin.se Academy of Scien.es(CAS)an. is due for laun.h in.*** is a compact X-ray telescope with a wide field-of-view(FOV)capable of en.ompassin. large portion. of Earth’s magn.tosphere from the van.age poin. of the SMILE *** is sen.itive to the soft X-rays produced by the Solar Win. Charge eXchan.e(SWCX)process produced when.heavy ion. of solar win. origin.in.eract with n.utral particles in.Earth’s *** provides a mechan.sm for boun.ary detection.within.the magn.tosphere,such as the position.of Earth’s magn.topause,because the solar win. heavy ion. have a very low den.ity in.region. of closed magn.tic field *** sen.itivity of the SXI is such that it can.poten.ially track.movemen.s of the magn.topause on.timescales of a few min.tes an. the orbit of SMILE will en.ble such movemen.s to be track.d for segmen.s lastin. man. *** is led by the Un.versity of Leicester in.the Un.ted k.n.dom(Uk.with collaboratin. organ.sation. on.hardware,software an. scien.e support within.the Uk.Europe,Chin. an. the Un.ted States.

关键词： Soft X-ray Imagin. micropore optics large area CCD