共查询到20条相似文献,搜索用时 15 毫秒
1.
B. T. Baisova V. I. Strunin N. N. Strunina G. Zh. Khudaiergenov 《Journal of Applied Spectroscopy》2008,75(5):739-742
We have determined the absolute populations of argon metastable states in the plasma of a high-frequency discharge in a pure
argon atmosphere and in a mixture of argon and silane.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 5, pp. 733–736, September–October, 2008. 相似文献
2.
Syuya Nakamura 《光谱学快报》2013,46(5):497-509
The emission intensities and the signal‐to‐background ratios (SBRs) of copper emission lines in the wavelength range 200–360 nm were observed from a medium‐voltage spark discharge plasma when argon or helium was employed as the surrounding gas. The observed copper spectra comprised Cu(I) lines having excitation energy of 3.8–9.3 eV, and Cu(II) lines assigned to three different transitions: 3d 84p–3d 84s transition (excitation energy of 8.2–9.2 eV), 3d 85s–3d 84p transition (13.4–13.6 eV), and the 3d 84d–3d 84p transition (14.2–14.8 eV). The Cu(I) lines have much smaller intensities in the helium plasma compared with the argon plasma, whereas the Cu(II) lines have similar intensities between both plasmas. The SBRs of some ionic copper lines are larger in the helium plasma compared with the argon plasma. Therefore, when an ionic line has to be measured in the analytical applications, the helium plasma should be recommended. 相似文献
3.
D. Sahu S. Bhattacharjee M. Bandyopadhyay A. K. Chakraborty 《Indian Journal of Physics》2011,85(12):1871-1878
A microwave driven multicusp plasma based volume negative ion source equipped with a magnetic filter is developed. Instead
of employing any electrodes or current carrying filaments, microwaves of frequency 2.45 GHz is used to generate plasma by
resonance heating mechanisms namely the electron cyclotron resonance (ECR) and upper hybrid resonances (UHR), occurring near
the boundary plasma layers. The principal process of negative ion production in hydrogen is dissociative attachment of low
energy (0.5–1.0 eV) electrons to vibrationally excited neutral molecules generated from high energy (15–20 eV) electron impact.
The source therefore necessitates two distinct spatial regions (a) production and (b) attachment chambers; which would contain
electrons with optimum cross section for the aforementioned processes. A biased grid after the magnetic filter further helps
to lower down the electron temperature to ≤1 eV which is favorable for the dissociative attachment process. 相似文献
4.
Chemical effects on the K shell fluorescence yields of Fe, Mn, Co, Cr and Cu compounds were investigated. Samples were excited
using 59.5 keV energy photons from a241 Am radioisotope source. K X-rays emitted by samples were counted by a Si(Li) detector with a resolution 160 eV at 5.9 keV.
Chemical effects on the K shell fluorescence yields (ωk) for Fe, Mn, Co, Cr and Cu compounds were observed. The values are
compared with theoretical, semiempirical fit and experimental ones for the pure elements. 相似文献
5.
Vineet Panchal Manoj Neergat Upendra Bhandarkar 《Journal of nanoparticle research》2011,13(9):3825-3833
Core–shell nanoparticles coated with carbon have been synthesized in a single chamber using a continuous and entirely low-pressure
plasma-based process. Nanoparticles are formed in an argon plasma using iron pentacarbonyl Fe(CO)5 as a precursor. These particles are trapped in a pure argon plasma by shutting off the precursor and then coated with carbon
by passing acetylene along with argon as the main background gas. Characterization of the particles was carried out using
TEM for morphology, XPS for elemental composition and PPMS for magnetic properties. Iron nanoparticles obtained were a mixture
of FeO and Fe3O4. TEM analysis shows an average size of 7–14 nm for uncoated particles and 15–24 nm for coated particles. The effect of the
carbon coating on magnetic properties of the nanoparticles is studied in detail. 相似文献
6.
Production and characterization of Nd,Cr:GSGG thin films on Si(001) grown by pulsed laser ablation 总被引:2,自引:0,他引:2
P.R. Willmott P. Manoravi K. Holliday 《Applied Physics A: Materials Science & Processing》2000,70(4):425-429
Nd,Cr:Gd3Sc2Ga3O12 (GSGG) thin films have been produced for the first time. They were grown on Si(001) substrates at 650 °C by pulsed laser
ablation at 248 nm of a crystalline Nd,Cr:GSGG target rod. The laser plume was analyzed using time-of-flight quadrupole mass
spectroscopy, and consisted of elemental and metal oxide fragments with kinetic energies typically in the range 10 to 40 eV,
though extending up to 100 eV. Although films deposited in vacuum using laser fluences of 0.8±0.1 J cm−2 reproduced the Nd,Cr:GSGG bulk stoichiometry, those deposited using fluences above ≈3 J cm−2 resulted in noncongruent material transfer and were deficient in Ga and Cr. Attempts to grow films using synchronized oxygen
or oxygen/argon pulses yielded mixed oxide phases. Under optimal growth conditions, the films were heteroepitaxial, with GSGG(001)[100]∥Si(001)[100],
and exhibited Volmer–Weber-type growth. Room-temperature emission spectra of the films suggest efficient non-radiative energy
transfer between Cr3+ and Nd3+ ions, similar to that of the bulk crystal.
Received: 1 October 1999 / Accepted: 15 October 1999 / Published online: 23 February 2000 相似文献
7.
The method of nitriding of metals in an electron beam plasma is used to change the current density and energy of nitrogen
ions by varying the electron beam parameters (5–20 A, 60–500 eV). An electron beam is generated by an electron source based
on a self-heated hollow cathode discharge. Stainless steel 12Kh18N10T is saturated by nitrogen at 500°C for 1 h. The microhardness
is measured on transverse polished sections to obtain the dependences of the nitrided layer thickness on the ion current density
(1.6–6.2 mA/cm2), the ion energy (100–300 eV), and the nitrogen-argon mixture pressure (1–10 Pa). The layer thickness decreases by 4–5 μm
when the ion energy increases by 100 V and increases from 19 to 33 μm when the ion current density increases. The pressure
dependence of the layer thickness has a maximum. These results are in conflict with the conclusions of the theory of the limitation
of the layer thickness by ion sputtering, and the effective diffusion coefficient significantly exceeds the well-known reported
data. 相似文献
8.
A comparison has been made between some kinds of configuration temperatures of the argon II spectrum and the temperatures of the atoms, ions and electrons for a hollow cathode, low-pressure, magnetically-confined, argon arc discharge in the 10–80 A current region. We found that thermalization by heavy particle collisions does not occur within the 4p group of the argon II spectrum (excitation energies 19·22-19·97 eV). and that relative line-intensity measurements over a large spectral range of 19–25 eV give hardly any relevant information on the electron temperature. Our conclusion is that the population densities of the excited levels are mainly determined by the excitation cross-section functions for the levels concerned. Furthermore, we have compared published transition probabilities (to 1970) for the argon II 4p group transitions. The mean values were obtained for 31 transitions with uncertainties (with two exceptions) between 1 and 20 per cent. 相似文献
9.
N.?A.?Borisevich A.?L.?Ivanov S.?M.?Kazakov A.?V.?Kukhto A.?I.?Mit'kovets D.?V.?Murtazaliev V.?A.?Povedailo O.?V.?Khristoforov 《Journal of Applied Spectroscopy》2005,72(4):503-508
The electron energy loss spectra (EELS) of indole, 3-indolyl propionic acid, 3-indolealdehyde, 3-dimethylaminomethylindole,
tryptophan, and N-acetyl-L-tryptophan in the gas phase upon excitation by monokinetic electrons with an energy of E0 = 11–50 eV are obtained. The structure of EELS is determined in the main by the indole chromophore; the side groups, except
for the C=O group of 3-indolealdehyde, exert an insignificant influence. The energy of the lower triplet level 3La is 3.3 eV for indole and its derivatives and 3.2 eV for tryptophan and N-acetyl-L-tryptophan. Four singlet transitions in
the region of 4.4–7.2 eV have been identified. The molecules studied, except for tryptophan, fluoresce in the gas phase on
excitation by electrons. At low values of E0 (10–25 eV), the fluorescence spectra are similar and are due to the indole fluorophore. Just as in the case of optical excitation,
fluorescence on excitation by electrons is associated with the 1Lb-S0 transitions. An increase in the energy E0 up to 60–80 eV leads to dissociation of a portion of the indole molecules and to the appearance of additional bands in the
fluorescence spectrum.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 4, pp. 468–472, July–August, 2005. 相似文献
10.
Yu. M. Smirnov 《Optics and Spectroscopy》2011,111(3):346-352
The excitation of singlet levels of the singly charged scandium ion is experimentally studied in collisions of slow electrons
with scandium atoms. At the exciting electron energy of 30 eV, 59 excitation cross sections are measured. In the electron
energy range of 0–200 eV, seven optical excitation functions are recorded. On the basis of these data the total excitation
cross sections are calculated for 11 even and 9 odd levels of Sc II, as well as the contribution of cascade population to
8 even and 7 odd levels. 相似文献
11.
Galina A. Vergunova Sergey Yu. Gus’kov Vladislav B. Rozanov Olga N. Rozmej 《Journal of Russian Laser Research》2010,31(5):509-518
We investigate theoretically the formation of a plasma in a plane layer of polymer foam (density ρ = 0.002 g/cm3 and thickness 800 μm) under the action of an external source of soft X-ray radiation under the conditions of PHELIX experiments. The incident
flux is assumed to have a Planck’s distribution over the spectrum with T
rad = 20–40 eV. In numerical calculations, the flux of incident X-ray radiation and the spectral constants of the target substance
are varied. The action of an external X-ray radiation source on a low-density foam substance with a density of 2 mg/cm3 causes a plasma to be formed with relatively homogeneous profiles of density and temperature T = 15–35 eV. Absorption of externalradiation energy is distributed in the volume. The plasma temperature increases with increase
in the external energy, and the energy passed through the plasma also increases. The results prove to be sensitive to the
values of optical constants used in numeral simulation. The spectral flux of external radiation passed through the plasma
is chosen as a criterion of correctness of the optical constants used in the calculations. In future experiments using the
PHELIX facility, we plan to investigate the slowing-down of an ion beam in a plasma formed as a result of indirect heating
of low-density polymer triacetate cellulose (TAC) foam with densities ρ = 0.001–0.01 g/cm3 under the action of a pulse of X-ray radiation, into which the laser radiation is preliminarily transformed. 相似文献
12.
R. Weißmann R. Koschatzky W. Schnellhammer K. Müller 《Applied Physics A: Materials Science & Processing》1977,13(1):43-46
Auger electron spectra of the transition metals Cr, Mn, Fe, Co and Ni as well as their oxides have been investigated in the
energy range between 0–100 eV. In each case of the clean metal surface the observed spectrum consists essentially of one Auger
line identified asM
2,3
VV transition. After oxidation a line doublet is observed revealing two transitions instead of one. Additional new Auger peaks
appear in the low energy range between 0–30 eV. The “splitting” of the Auger line can be explained as resulting from aM
2,3
V
dVd and aM
2,3
V
pVp transition. The latter is characteristic for the compound and can in a simple way be interpreted as a cross transition. 相似文献
13.
Yu. M. Smirnov 《Optics and Spectroscopy》2011,110(4):493-499
The electron-impact excitation of even levels of Tm II from the ground level of the thulium atom is studied by the method
of extended crossing beams with recording the optical emission of excited ions. At the exciting electron energy of 50 eV,
54 excitation cross sections are measured. In the electron energy range of 0–200 eV, 12 excitation optical functions are recorded.
The most probable channels of the excitation process are discussed. 相似文献
14.
Yu. M. Smirnov 《Journal of Applied Spectroscopy》2007,74(3):315-320
The extended crossed-beam method has been used to study excitation of high-lying levels in the tungsten atom. 40 excitation
cross sections of WI spectral lines have been measured for exciting electron energy 50 eV. Two optical excitation functions
were recorded in the electron energy range 0–200 eV. The results obtained were used to calculate the total excitation cross
sections of 24 odd WI energy levels.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 3, pp. 283–288, May–June, 2007. 相似文献
15.
G. Tsilimis J. Kutzner H. Zacharias 《Applied Physics A: Materials Science & Processing》2003,76(5):743-749
An extreme ultraviolet (EUV) laser light source based on high-harmonic generation is presented. Coherent radiation in the
photon energy range hν=20–120 eV is produced in the conversion media argon, neon and helium. High-harmonic radiation in the
energy range 20–50 eV is applied to investigate photoemission spectra of Pt (111) and CO/Pt (111). In the photoemission spectra
of the clean surface, new secondary electron emission structures are found which influence the cross section analysis of the
CO states. When taking these Pt resonances into consideration, the 4σ and 5σ CO shape resonances are found at photon energies
of 37 eV and 28 eV, respectively. Additionally, a resonance at hν=31 eV is also observed for the CO 1π state, in contrast
to formerly published experimental data. Experimental and theoretical data suggest that this resonance is not connected to
the well-known shape resonances in the σ-channel. Based on theoretical approaches, it is identified as an autoionization resonance.
Received: 8 April 2002 / Accepted: 22 May 2002 / Published online: 22 November 2002
RID="*"
ID="*"Corresponding author. Fax: +49-251/833-3604, E-mail: kutzner@uni-muenster.de 相似文献
16.
C. G. Jin T. Yu Z. F. Wu F. Wang M. Z. Wu Y. Y. Wang Y. M. Yu L. J. Zhuge X. M. Wu 《Applied Physics A: Materials Science & Processing》2012,106(4):961-966
Al-doped zinc oxide (AZO) films are prepared on quartz substrates by dual-ion-beam sputtering deposition at room temperature
(∼25°C). An assisting argon ion beam (ion energy E
i
=0–300 eV) directly bombards the substrate surface to modify the properties of AZO films. The effects of assisted-ion beam
energy on the characteristics of AZO films were investigated in terms of X-ray diffraction, atomic force microscopy, Raman
spectra, Hall measurement and optical transmittance. With increasing assisting-ion beam bombardment, AZO films have a strong
improved crystalline quality and increased radiation damage such as oxygen vacancies and zinc interstitials. The lowest resistivity
of 4.9×10−3Ω cm and highest transmittance of above 85% in the visible region were obtained under the assisting-ion beam energy 200 eV.
It was found that the bandgap of AZO films increased from 3.37 to 3.59 eV when the assisting-ion beam energy increased from
0 to 300 eV. 相似文献
17.
In this study, the optical properties as well as mechanical and electrical degradation of low-density polyethylene (LDPE)/polypropylene
fiber (PP fiber) (10–50% PP fiber), polypropylene (PP)/PP fiber (10–50% PP fiber), and LDPE/diamond (0.1–3% diamond) blends,
which are prepared by hot pressing method, with changing thicknesses ranging from 30 to 225 μm, are compared. The spectra,
in the wavelength range 200–2500 nm, are examined. Based on optical absorption spectra obtained, Tauc graphs are plotted.
Determined values of the direct optical energy gap (E
d
opt
), the indirect optical energy gap (E
i
opt
), the width of the band (ΔE), and ultraviolet transmittance (TUV) are listed. The direct E
d
opt
and indirect E
i
opt
values for organic blends are in the range of 3.10–3.17 eV and 1.52–2.99 eV; for inorganic blends they are 1.80–4.13 eV and
1.55–4.7 eV respectively. The electrical strength (ε) and the mechanical tension (σ) have been investigated, and graphs (the
dependence of the electrical life time log τε on ε) are given. The experimental results are analyzed from the viewpoint of the validity of the thermofluctuation theory.
LDPE and LDPE/0.5% diamond composite parameters consecutively changed: σ from 68 to 82 MPa, ε from 60·106 to 85·106 V/m, mechanical lifetime τσ from 10 to 1.5·105 sec, electrical lifetime τε from 2· 103 to 2·105 sec, and structure-sensitive parameters γ and χ — from 1.48 to 1.18 (J)MPa/mole and from 0.97 to 0.70 (J)Vm−1/mole respectively. The values of mechanical and electrical durability were observed to increase by 20 and 41%, respectively,
for LDPE/0.5% diamond composite.
Published in Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 5, pp. 677–683, September–October, 2007. 相似文献
18.
A.?Giuliani P.?Lim?o-Vieira D.?Duflot A. R.?Milosavljevic B. P.?Marinkovic S. V.?Hoffmann N.?Mason J.?Delwiche M.-J.?Hubin-Franskin 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,51(1):97-108
The electronic spectroscopy of isolated tetrahydrofuran (THF) in the gas phase has been investigated using high-resolution
photoabsorption spectroscopy in the 5.8–10.6 eV with absolute cross-section measurements derived. In addition, an electron
energy loss spectrum was recorded at 100 eV and 10° over the 5–11.4 eV range. The He(I) photoelectron spectrum was also collected
to quantify ionisation energies in the 9–16.1 eV spectral region. These experiments are supported by the first high-level
ab initio calculations performed on the excited states of the neutral molecule and on the ground state of the positive ion.
The excellent agreement between the theoretical results and the measurements allows us to solve several discrepancies concerning
the electronic state spectroscopy of THF. The present work reconsiders the question of the lowest energy conformers of the
molecule and its population distribution at room temperature.
Electronic supplementary material Supplementary Online Material 相似文献
19.
O. Sueoka C. Makochekanwa M. Kimura 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,37(3):377-383
Total cross-sections (TCSs) for 0.2–1000 eV positrons and 0.4–1000 eV
electrons colliding with normal-octane and cyclo-octane molecules have been
studied using a relative measurement method. The TCS curves for positron and
electron vary smoothly and compare well with other alkane molecules, in
order of increasing carbon number. For positron scattering, weak humps at
1.5–2.5 eV for both normal- and cyclo-octane were observed. In the energy
range lower than 2.2 eV, positron TCSs are roughly equal to or larger than
electron TCSs. For electron scattering, a resonance peak at 8 eV and a
shoulder at 25.0 eV were observed for both molecules. Over all the energy
range, the TCS values for normal-octane are larger than those of
cyclo-octane. The positron and electron TCS data for normal- and
cyclo-octane molecules are briefly compared with those for normal- and
cyclo-hexane. 相似文献
20.
M. Ijjaali K. Kowalski T. Bak B. Dupre C. Gleitzer J. Nowotny M. Rekas C. C. Sorrell 《Ionics》2001,7(4-6):351-359
This paper reports the results of the electrical conductivity measurements for polycrystalline specimens of undoped and Cr-doped
CoO in the ranges of p(O2) (10−5 – 105 Pa) and temperature (1223 – 1373 K). The experimental data are considered in terms of the effect of Cr on semiconducting
properties of CoO. It is shown that Cr results in a decrease of the reciprocal of the p(O2) exponent of electrical conductivity, however, the obtained experimental values are substantially lower than those predicted
by defect chemistry. The activation energy of the electrical conductivity remains independent of p(O2) and Cr content (at the level of about 0.5 eV) except strongly reduced CoO, at p(O2)=2.10−4 Pa, of which the activation energy is substantially higher. Thermopowervs p(O2) exhibits maximum at p(O2)=10 Pa (except of thermopower data for Cr-doped CoO at the highest temperature). The experimental data are considered in
terms of the effect of both p(O2) and Cr on semiconducting properties. 相似文献