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Journal of materials Science & Technology 2017年第7期33卷 744-750页

作者： b.Q.Geng Y.Q.ma m.Wang Z.L.Ding W.H.Song b.c.Zhao Key Laboratory of materials Physics Institute of Solid State Physics Chinese Academy of Sciences Hefei 230031 China

The coFe_2alloy（cF） was prepared by reducing coFe_2O_4 in the H_2 ambient. Subsequently the cF sample was nitrided in the NH_3 atmosphere to produce the composite of coFe_2N and coFe_2. The magnetostriction, thermal expansion, resistivity and corrosion resistance of cF sample and the nitrided sample（cFN）at 1000？c were investigated. The saturation magnetostriction coefficiency λ_s and thermal expansion coefficient ？ at 300 K for the nitrided cFN were 50 ppm and 10 ppm/K, respectively, approximately equal to those for the cF sample. However, compared with cF, cFN presents a decrease in temperature coefficient R_λ（300 K） of magnetostriction by 11%. The smaller resistivity and improved corrosion resistance in the H_2SO_4 solution may expand the applications of the coFe_2 in the fields needing lower resistivity or in the acidic environment.

关键词： coFe alloy coFe_2N alloy magnetostriction Resistivity corrosion resistance

chemical forms and extractability of iron in sediments of three contrasting lakes of china and UK

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Journal of Environmental Sciences 2003年第6期15卷 728-733页

作者： Gibson c.E.,Stewart b.m. Key Laboratory of Terrestrial Ecological Process Institute of Applied Ecology chinese Academy of Sciences Department of Agricultural and Environmental Science Queen's University belfast Shenyang 110016 china Newforge Lane belfast bT9 5PX UK

Iron is a limiting factor for the eutrophication of lakes, especially those lakes that are enriched with phosphorus. Extractability of iron in sediments of West Lake and Taihu Lake in china and Lower Lough Erne in Northern Ireland of UK was comparatively investigated on the basis of analysing chemical forms of iron using different extractants. It was shown that extractable iron in sediments of the lakes was greatly different using various extractants. Reactive iron or easily released iron such as “active" iron oxides, total free iron oxide and water-soluble iron was not high, only accounting for 0.01%—0.15% of total iron. The efficiency of the extractants for exchangeable iron was decreased in the sequence 0.1 mol/L Hcl DTPA+TEA mixed solution > 1 mol/L NH 4OAc > 0.5 mol/L mgcl 2 = 0.5 mol/L cacl 2. It seems that the complexion of iron by organic matter was not strong b.c.use the concentration of organically bound iron was significantly lower than the concentration it was forecasted. Extractable iron is not entirely consistent with or dependent on total iron in lake sediments. To a certain extent, phosphate can inhibit the release of iron in sediments of the lakes. The selection of extractants is thus the first key step to evaluate bioavailability of iron in lake sediments.

关键词： iron chemical form extractability lake sediment eutrophication

EmDEN-FOWLER TYPE SYSTEm:NOETHER SYmmETRIES AND FIRST INTEGRALS

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Acta mathematica Scientia 2012年第5期32卷 1959-1966页

作者： b.muatjetjeja c.m.Khalique International Institute for Symmetry Analysis and mathematical modelling Department of Mathematical SciencesNorth-West UniversityMafikeng CampusPrivate Bag X 2046Mmabatho 2735Republic of South Africa

We classify a generalized coupled singular Emden-Fowler type system ＋a（t）vn=0,v＋b（t）um=0 with respect to the standard first-order Lagrangian according to the Noether point symmetries which it *** integrals of the various cases which admit Noether point symmetries are then *** system was discussed in the literature from the view-point of existence and uniqueness of positive solutions.

关键词： Lagrangian Noether symmetry first integrals Emden-Fowler type system Gauge function

Hole burning in the Fock Space: from Single to Several Holes

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chinese Physics Letters 2001年第11期18卷 1467-1469页

作者： b.baseia J.m.c.malbouisson Instituto de Fisica Universidade Federal de Goias74001-970GoianiaGOBrazil Instituto de Fisica Universidade Federal da Bahia40210-340SalvadorBABrazil

In our previous papers we have studied the production of a single hole in the photon number distribution of a field state [Phys. Lett. A 240 (1998) 277;253 (1999) 123]. In this letter we extend the procedure for the c... 详细信息

关键词： letter creation distribution

Effect of the textural properties of rocks on their crushing and grinding features

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Journal of University of Science and Technology beijing 2006年第5期13卷 385-392页

作者： b. Kekec m. Unal c. Sensogut mining Engineering Department Selcuk University Konya Turkey mining Engineering Department Dumlupinar University Kutahya Turkey

To study the effect of the textural properties of rocks on their crushing feature, the distribution of particle size, the texture, grinding and crushing characteristics of the rocks were investigated, and the relations among them were then analyzed using statistical methods. The relations between the textural properties and the physical and mechanical features of rocks were determined.

关键词： rock textural properties crushing grinding

ZrO2 strengthened NiAl/cr（mo,Hf） composite fabricated by powder metallurgy

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Progress in Natural Science:materials International 2012年第3期22卷 231-236页

作者： L.Y. Sheng a,b, J.T. Guo c, T.F. Xi a,b, b.c. Zhang c, H.Q. Ye c a PKU-HKUST ShenZhen-Hong Kong Institution, Shenzhen 518057, china b.c.llege of Engineering, Peking University, beijing 100871, china c Institute of metal Research, chinese Academy of Sciences, Shenyang 110016, china [a] PKU-HKUST ShenZhen-Hong Kong Institution Shenzhen 518057 China [b] college of Engineering Peking University Beijing 100871 China [c] Institute of metal Research Chinese Academy of Sciences Shenyang 110016 China

The ZrO2 ceramic particles strengthened NiAl/cr(mo,Hf) composite was fabricated from the rapidly solidified NiAl/cr(mo,Hf) pre-alloyed powder and the ZrO2 powder by powder metallurgy technique. microstructure examination revealed that in the prepared composite NiAl and cr(mo) phases distributed at the eutectic cell boundary b.c.me coarse but many cr(mo) platelets inside the eutectic cell were broken, which was different from the original powder. moreover, fine Ni2AlHf and Hf solid solution particles distributed uniformly in the composite, and the ZrO2 particles mainly segregated along eutectic cell boundary. In addition, twin crystal and stacking faults were observed inside of ZrO2 grains. The experimental results showed that the ZrO2 ceramic particles strengthened NiAl/cr(mo,Hf) composite exhibited better room temperature and high temperature mechanical properties than the NiAl/cr(mo,Hf) alloy, which may be attributed to the fine structure and the strengthening effect of ZrO2 particles.

关键词： NiAl intermetallics NiAl/cr(mo) composite Powder metallurgy ZrO2 strengthening

Semi-analytical investigation of heat transfer in a porous convective radiative moving longitudinal fin exposed to magnetic field in the presence of a shape-dependent trihybrid nanofluid

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Applied mathematics and mechanics(English Edition) 2024年第1期45卷 197-216页

作者： c.G.PAVITHRA b.J.GIREESHA m.L.KEERTHI Department of PG Studies and Research in mathematics Kuvempu UniversityShankaraghatta 577451India Department of mathematics and Statistics M.S.Ramaiah University of Applied SciencesBengaluru 560058India

The thermal examination of a non-integer-ordered mobile fin with a magnetism in the presence of a trihybrid nanofluid(Fe_3O_4-Au-Zn-blood) is carried out. Three types of nanoparticles, each having a different shape, are considered. These shapes include spherical(Fe_3O_4), cylindrical(Au), and platelet(Zn) configurations. The combination approach is utilized to evaluate the physical and thermal characteristics of the trihybrid and hybrid nanofluids, excluding the thermal conductivity and dynamic viscosity. These two properties are inferred by means of the interpolation method based on the volume fraction of nanoparticles. The governing equation is transformed into a dimensionless form, and the Adomian decomposition Sumudu transform method(ADSTm) is adopted to solve the conundrum of a moving fin immersed in a trihybrid nanofluid. The obtained results agree well with those numerical simulation results, indicating that this research is reliable. The influence of diverse factors on the thermal overview for varying noninteger values of γ is analyzed and presented in graphical representations. Furthermore, the fluctuations in the heat transfer concerning the pertinent parameters are studied. The results show that the heat flux in the presence of the combination of spherical, cylindrical, and platelet nanoparticles is higher than that in the presence of the combination of only spherical and cylindrical nanoparticles. The temperature at the fin tip increases by 0.705 759% when the value of the Peclet number increases by 400%, while decreases by 11.825 13% when the value of the Hartman number increases by 400%.

关键词： convection radiation moving longitudinal fin Adomian decomposition Sumudu transform method(ADSTm) trihybrid nanofluid magnetic field

Fundamental Groups of Graphs of cyclic Subgroup Separable and Weakly Potent Groups

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Algebra colloquium 2021年第1期28卷 119-130页

作者： m.S.m.Asri K.b.Wong P.c.Wong Institute of mathematical Sciences Faculty of ScienceUniversity of Malaya50603 Kuala LumpurMalaysia

We give a characterization of the cyclic subgroup separability and weak potency of the fundamental group of a graph of polycyclic-by-finite groups and free-by-finite groups amalgamating edge subgroups of the form×D,w... 详细信息

关键词： HNN extensions fundamental groups of graphs of groups weakly potent residually finite

GIANT mAGNETO-ImPEDANcE OF PATTERNED FeSib.c./FeSib TRI-LAyer FILmS

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Acta metallurgica Sinica(English Letters) 2003年第5期16卷 327-331页

作者： X.H. mao, Y. Zhou, m.S. Wu and b.c. caiKey Laboratory for Thin Film and microfabrication of ministry of Education, Research Institute of micro/ Nanometer Science and Technology, Shanghai Jiaotong University, Shanghai 200030, china Key Laboratory for Thin Film and microfabrication of ministry of Education Research Institute of Micro/Nanometer Science and Technology Shanghai Jiaotong University Shanghai 200030 China

Sensitive magnetic field sensor with good performances can be fabricated utilizing the giant magneto-impedance (GmI) effect of soft magnetic multi-layer thin films. The transverse and longitudinal GmI effect in patterned FeSib.c./FeSib tri-layer films with the change of external magnetic field and frequency were studied at the same time. The change of the impedance of the films with the external magnetic fieldand frequency was shown. comparing the longitudinal and transverse effect, the transverse effect has a larger linear range from zero magnetic field to a quite large magnetic field at all frequencies, and the change still were not saturated until the external magnetic field reached 1.2×104A/m, which illustrated that the films can be utilized to detect larger magnetic fields than now presented GmI sensors.

关键词： giant magneto-impedance effect FeSib.c./FeSib films tri- layer films

Delayed Ionization and Delayed Detachment in molecules and clusters

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chinese Journal of chemical Physics 2009年第2期22卷 162-170页

作者： F. Lépine b. baguenard b. concina m. A. Lebeault c. bordas Université de Lyon F-69522 Lyon France Université Lyon 1 Villeurbanne cNRS UMR 5579 LASIM

The evolution of a molecular system excited above its ionization threshold depends on a number of parameters that include the nature of the excited states and their couplings to the various continua. The general nature of the processes governing this evolution depends also essentially on the complexity of the molecule, more precisely on its size, density of states, and strength of the couplings among the various internal degrees of freedom. In this paper we address the question of the transition between autoionization that prevails in small molecules, and delayed ionization occurring in larger molecules or clusters. This transition is illustrated by autoionization of Na2 Rydberg states on one hand, delayed ionization in fullerene c60, and delayed detachment in small cluster anions on the other hand. All processes are studied in the case of nanosecond laser excitation, corresponding to a rather slow deposition of the internal energy.

关键词： Autoionization Autodetachment Thermionic emission