共查询到20条相似文献,搜索用时 31 毫秒
1.
Huailiang Xu Tomoya Okino Kaoru Yamanouchi 《Applied Physics A: Materials Science & Processing》2011,104(3):941-945
Ultrafast delocalization of hydrogen atoms in allene (CH2=C=CH2) induced by intense laser fields was investigated by the Coulomb explosion coincidence momentum imaging method. On the basis
of the kinetic energy distributions of the fragment ions produced through the two three-body Coulomb explosion pathways, C3H43+ ? H+ + CH+ + C2H2+\mathrm{C}_{3}\mathrm{H}_{4}^{3+} \rightarrow \mathrm{H}^{+} + \mathrm{CH}^{+} + \mathrm{C}_{2}\mathrm{H}_{2}^{+} and C3H43+ ? H+ + C2H+ +CH2+\mathrm{C}_{3}\mathrm{H}_{4}^{3+} \rightarrow \mathrm{H}^{+} + \mathrm{C}_{2}\mathrm{H}^{+} +\mathrm{CH}_{2}^{+}, and the proton maps for both pathways, it was shown that the decomposition proceeds in a stepwise manner as well as in a
concerted manner. The time scale of the hydrogen migration within an allene molecule was estimated to be ∼20 fs. 相似文献
2.
V. V. Afrosimov A. A. Basalaev V. V. Kuz’michev M. N. Panov O. V. Smirnov 《Technical Physics》2016,61(3):342-348
The relative cross sections of elementary processes occurring in single collisions of tryptophan molecules in the gaseous phase with He2+ ions with energy 4 keV/u are measured using time-of-flight mass spectrometry for studying the mechanism of radiation damage of amino acid molecules. The fragmentation channels for intermediate singly and doubly charged tryptophan molecular ions formed during one-electron capture, two-electron capture, and electron capture with ionization are investigated. Significant difference is observed in the mass spectra of fragmentation of intermediate doubly charged ions formed during the capture with ionization and double capture, which is associated with different energies of excitation of {C11H12N2O2}2+* ions. 相似文献
3.
Time evolution of the Infrared Laser Induced Breakdown Spectroscopy of DNA bases Guanine and Adenine
L. Diaz L. Rubio J. J. Camacho 《Applied Physics A: Materials Science & Processing》2013,110(4):847-851
Laser-Induced Breakdown Spectroscopy (LIBS) of DNA bases Guanine and Adenine was studied using a high-power CO2 pulsed laser (λ=10.591 μm, τ FWHM=64 ns and fluences ranging from 25 to 70 J/cm2). The strong emission of the adenine and guanine plasma, collected using a high-resolution spectrometer, at medium-vacuum conditions (4 Pa) and at 1 mm from the target, exhibits excited molecular bands of CN (B2 Σ +–X2 Σ +) and excited neutral H and ionized N+ and C+. The medium-weak emission is due to excited species C2+, C3+, N, O, O+, O2+ and molecular band systems of $\mathrm{C}_{2}(\mathrm{d}^{3}\varPi_{\mathrm{g}}\mbox{--}\mathrm{a}^{3}\varPi_{\mathrm{u}};\ \mathrm{D}^{1}\varSigma_{\mathrm{u}}^{+}\mbox{--}\mathrm{X}^{1}\varSigma_{\mathrm{g}}^{+})$ , OH(A2 Σ +–X2 Π), NH(A3 Π–X3 Σ ?), CH(A2 Π–X2 Π), $\mathrm{N}_{2}^{+}(\mathrm{B}^{2}\varSigma_{\mathrm{u}}^{+}\mbox{--} \mathrm{X}^{2}\varSigma_{\mathrm{g}}^{+})$ and N2(C3 Π u–B3 Π g). We focus our attention on the temporal evolution of different atomic/ionic and molecular species. The velocity distributions for various (different) species were obtained from time-of-flight (TOF) measurements. Intensities of some lines from C+ were used for determining electron temperature and their Stark-broadened profiles were employed to estimate the temporal evolution of electron density. 相似文献
4.
Ashok Kumar Baral V. Sankaranarayanan 《Applied Physics A: Materials Science & Processing》2010,98(2):367-373
The nanocrystalline material of 15 mol% Gd-doped ceria (Ce0.85Gd0.15O2−δ
) was prepared by citrate auto ignition method. The electrical study and dielectric relaxation technique were applied to investigate
the ionic transport process in this nanocrystalline material with an average grain size of 13 nm and the dynamic relaxation
parameters are deduced in the temperature range of 300–600°C. The ionic transference number in the material is found to be
0.85 at 500°C at ambient conditions. The oxygen ionic conduction in the nanocrystalline Ce0.85Gd0.15O2−δ
material follows the hopping mechanism. The grain boundary relaxation is found to be associated with migration of charge
carriers. The frequency spectra of modulus M″ exhibited a dielectric relaxation peak corresponding to defect associates
(Gd-Vo\blacksquare \blacksquare)\blacksquare(\mathrm{Gd}\mbox{-}\mathrm{V}_{\mathrm{o}}^{_{_{{\blacksquare\,\blacksquare}}}})^{_{_{{\blacksquare}}}}. The material exhibits very low values of migration energy and association energy of the oxygen vacancies in the long-range
motion, i.e., 0.84 and 0.07 eV, respectively. 相似文献
5.
Magnetocaloric properties of as-quenched Ni50.4Mn34.9In14.7 ferromagnetic shape memory alloy ribbons
Sánchez Llamazares J. L. García C. Hernando B. Prida V. M. Baldomir D. Serantes D. González J. 《Applied Physics A: Materials Science & Processing》2011,103(4):1125-1130
The temperature dependences of magnetic entropy change and refrigerant capacity have been calculated for a maximum field change
of Δ
H=30 kOe in as-quenched ribbons of the ferromagnetic shape memory alloy Ni50.4Mn34.9In14.7 around the structural reverse martensitic transformation and magnetic transition of austenite. The ribbons crystallize into
a single-phase austenite with the L21-type crystal structure and Curie point of 284 K. At 262 K austenite starts its transformation into a 10-layered structurally
modulated monoclinic martensite. The first- and second-order character of the structural and magnetic transitions was confirmed
by the Arrott plot method. Despite the superior absolute value of the maximum magnetic entropy change obtained in the temperature
interval where the reverse martensitic transformation occurs
(|\varDelta SMmax|=7.2 J kg-1 K-1)(|\varDelta S_{\mathrm{M}}^{\max}|=7.2\mbox{ J}\,\mbox{kg}^{-1}\,\mbox{K}^{-1}) with respect to that obtained around the ferromagnetic transition of austenite
(|\varDelta SMmax|=2.6 J kg-1 K-1)(|\varDelta S_{\mathrm{M}}^{\max}|=2.6\mbox{ J}\,\mbox{kg}^{-1}\,\mbox{K}^{-1}), the large average hysteretic losses due to the effect of the magnetic field on the phase transformation as well as the narrow
thermal dependence of the magnetic entropy change make the temperature interval around the ferromagnetic transition of austenite
of a higher effective refrigerant capacity (RCmagneff=95J kg-1\mathrm{RC}^{\mathrm{magn}}_{\mathrm{eff}}=95\mbox{J}\,\mbox{kg}^{-1} versus RCstructeff=60J kg-1)\mathrm{RC}^{\mathrm{struct}}_{\mathrm{eff}}=60\mbox{J}\,\mbox{kg}^{-1}). 相似文献
6.
P. Ortwein W. Woiwode S. Wagner M. Gisi V. Ebert 《Applied physics. B, Lasers and optics》2010,100(2):341-347
A high-resolution spectrometer based on a vertical-cavity surface-emitting laser (VCSEL) was developed and used to determine
the line strength S(T
0)=12.53(11)×10−21 cm−1/(molec cm−2) and the self-broadening coefficient
g0HCl=0.021787(61)\gamma^{0}_{\mathrm{HCl}}=0.021787(61)
cm−1/atm of the R(3) absorption line in the first rovibrational overtone (2←0) band of H35Cl. Furthermore, the first laser-based high-pressure study on the pressure broadening of HCl by He, N2 and
O2(g0N2=0.07292(5)\mathrm{O}_{2}(\gamma^{0}_{\mathrm{N}_{2}}=0.07292(5)
cm−1/atm,
g0He=0.02113(1)\gamma^{0}_{\mathrm{He}}=0.02113(1)
cm−1/atm,
g0O2=0.03978(6)\gamma^{0}_{\mathrm{O}_{2}}=0.03978(6)
cm−1/atm) is presented covering pressures of up to 1 MPa. The results are compared to previously available low-pressure data. 相似文献
7.
S. Corradetti L. Biasetto M. Manzolaro D. Scarpa A. Andrighetto S. Carturan G. Prete P. Zanonato D. W. Stracener 《The European Physical Journal A - Hadrons and Nuclei》2011,47(10):119
The temperature dependence of neutron-rich isotope yields was studied within the framework of the HRIBF-SPES Radioactive Ion
Beams (RIB) project. On-line release measurements of fission fragments from a uranium carbide target at $\ensuremath 1600 {}^{\circ}\mathrm{C}$\ensuremath 1600 {}^{\circ}\mathrm{C} , 1800 °C\ensuremath 1800 {}^{\circ}\mathrm{C} and 2000 °C\ensuremath 2000 {}^{\circ}\mathrm{C} were performed at ORNL (USA). The fission reactions were induced by a 40MeV proton beam accelerated into a uranium carbide
target coupled to a plasma ion source. The experiments allowed for tests of performance of the SPES multi-foil target prototype
loaded with seven UC2/graphite discs (ratio C/U = 4 with density about 4g/cm3. 相似文献
8.
Michalis Velegrakis Maria Massaouti Maria Jadraque 《Applied Physics A: Materials Science & Processing》2012,108(1):127-131
Titanium oxide cluster cations $\mathrm{Ti}_{x}\mathrm{O}_{y}^{+}$ are produced in a molecular beam by combining laser ablation of titanium with the supersonic expansion of oxygen into vacuum. The size distribution of the clusters produced is analyzed by time-of-flight reflectron mass spectrometry. The stable clusters appearing in the mass spectrum can be described by the general formula $(\mathrm{TiO})_{m}(\mathrm{TiO}_{2})_{n}(\mathrm{O}_{2})_{k}^{+}$ (with m,n=0,1,2,?? and k=0,1). Additionally, collision-induced dissociation studies of mass selected clusters colliding with Kr atoms in a gas cell have been performed. The results show that the clusters lose neutral O2, TiO and/or (TiO2) n units, and the remaining charged fragments are those with the lowest ionization potentials. From these results the fragmentation cross section of the selected clusters is obtained. 相似文献
9.
Tonietto Serena Nestola Fabrizio Redhammer Gunther J. Silvestri Alberta Molin Gianmario Bruno Marco 《Applied Physics A: Materials Science & Processing》2011,103(1):207-212
The mineral inclusions of two orange glass tesserae from paleo-Christian mosaics were investigated in order to derive the
melting temperature reached during their production (sourced from Padua and Vicenza, Veneto region, Italy). In particular,
clinopyroxene crystals were studied by single-crystal X-ray diffraction and electron microprobe WDS analysis. The crystals
show C2/c symmetry, typical of disordered Ca/Na and Mg/Al distributions indicating high-temperature of formation (>700°C). The cation
site populations were obtained by combining results from the two experimental techniques enabled us to derive the following
stoichiometric formula:
lM2[Ca0.819Na0.172Mn0.006K0.003]M1[Mg0.765Fe3+0.210 Cu0.015Ti0.006Zn0.006]T[Si1.933Al0.037Sn0.024]O6\begin{array}{l}{}^{M2}[\mathrm{Ca}_{0.819}\mathrm{Na}_{0.172}\mathrm{Mn}_{0.006}\mathrm{K}_{0.003}]{}^{M1}[\mathrm{Mg}_{0.765}\mathrm{Fe}^{3+}_{0.210}\\[3pt]\quad{}\mathrm{Cu}_{0.015}\mathrm{Ti}_{0.006}\mathrm{Zn}_{0.006}]{}^{T}[\mathrm{Si}_{1.933}\mathrm{Al}_{0.037}\mathrm{Sn}_{0.024}]\mathrm{O}_{6}\end{array} 相似文献
10.
This paper considers Hardy–Lieb–Thirring inequalities for higher order differential operators. A result for general fourth-order
operators on the half-line is developed, and the trace inequality
|