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1.
This paper reports that the absorption spectra of H2O^+ have been measured by tunable mid-infrared diode laser spectroscopy in the spectral range of 1100-1380 cm^-1. The H2O+ ions are generated in an AC glow discharge of the gaseous mixtures of H2O/He and detected with the velocity modulation technique. Forty new lines are assigned to the ν2 fundamental band of H2O^+ (X^2B1). The observed lines together with other data published previously are fitted to the standard effective Hamiltonian of an asymmetric top, yielding a set of improved rotational constants, spin-rotation constants and their quartic and sextic centrifugal distortion constants for the ν2=1 vibrational state of H2O+. 相似文献
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Calculations of state-selective differential cross sections for charge transfer in collisions between O3+ and H2 下载免费PDF全文
The non-dissociative charge-transfer processes in collisions between O^3+ and H2 are investigated by using the quantum-mechanical molecular-orbital coupled-channel (QMOCC) method. The adiabatic potentials and radial coupling matrix elements utilized in the QMOCC calculations are obtained with the spin-coupled valence-bond approach. Electronic and vibrational state-selective differential cross sections are presented for projectile energies of 0.1, 1.0 and 10.0eV/u in the H2 orientation angles of 45° and 89°. The electronic and the vibrational state-selective differential cross sections show similar behaviours: they decrease as the scattering angle increases, and beyond a specific angle the oscillating structures appear. Moreover, it is also found that the vibrational state-selective differential cross sections are strongly orientation-dependent, which provides a possibility to determine the orientations of molecule H2 by identifying the vibrational state-selective differential scattering processes. 相似文献
4.
In order to understand the recycling and emission processes of hydrogen atoms in HT 7, spectral profiles of the Dα(Hα) line emitted in front of the limiter have been observed with a high-resolution spectrometer and simulated by using the neutral particle transport code DEGAS 2. The results show that four processes are necessary to interpret the Dα(Hα) line shape: 1) atom desorption, 2) molecular dissociation, 3) particle reflection, and 4) charge-exchange. The products of the first two processes are cold atoms which emit photons near the peak of Dα(Hα) line shape, and those from the last two are warm atoms contributing to the blue side of the spectrum. For a typical ohmic discharge (shot 68520 ne(0) ≈ 3× 10^19 m^-3. these components contribute 32%, 15%, 32% and 21%, respectively. Dα(Hα) line shapes under different plasma parameters are also discussed in this paper. 相似文献
5.
《中国物理 B》2021,30(5):56106-056106
Lattice defects induced by ion implantation into Si C have been widely investigated in the decades by various techniques. One of the non-destructive techniques suitable to study the lattice defects in Si C is the optical characterization. In this work, confocal Raman scattering spectroscopy and photoluminescence spectrum have been used to study the effects of 134-ke V H_2~+ implantation and thermal treatment in the microstructure of 6 H-Si C single crystal. The radiation-induced changes in the microstructure were assessed by integrating Raman-scattering peaks intensity and considering the asymmetry of Raman-scattering peaks. The integrated intensities of Raman scattering spectroscopy and photoluminescence spectrum decrease with increasing the fluence. The recovery of the optical intensities depends on the combination of the implantation temperature and the annealing temperature with the thermal treatment from 700℃ to 1100℃. The different characterizations of Raman scattering spectroscopy and photoluminescence spectrum are compared and discussed in this study. 相似文献
6.
Using the different level of methods B3P86, BLYP, B3PW91, HF, QCISD、 CASSCF (4,4) and MP2 with the various basis functions 6-311G^**, D95, cc-pVTZ and DGDZVP, the calculations of this paper confirm that the ground state is X^-3B1 with C2v group for CH2. Furthermore, the three kinds of theoretical methods, i.e. B3P86、 CCSD(T, MP4) and G2 with the same basis set cc-pVTZ only are used to recalculate the zero-point energy revision which are modified by scaling factor 0.989 for the high level based on the virial theorem, and also with the correction for basis set superposition error. These results are also contrary to X^-3∑^-g for the ground state of CH2 in reference. Based on the atomic and molecular reaction statics, this paper proves that the decomposition type (1) i.e. CH4 →CH2+H2, is forbidden and the decomposition type (2) i.e. CH4→CHa+H is allowed for CH4. This is similar to the decomposition of SiH4. 相似文献
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The role of hydrogen in hydrogenated microcrystalline silicon film and in deposition process with VHF-PECVD technique 下载免费PDF全文
The role of hydrogen in hydrogenated microcrystalline silicon ($\mu $c-Si:H)
thin films in deposition processes with very high frequency
plasma-enhanced chemical vapour deposition (VHF-PECVD) technique have been
investigated in this paper. With \textit{in situ} optical emission spectroscopy (OES)
diagnosis during the fabrication of $\mu $c-Si:H thin films under different
plasma excitation frequency $\nu _{\rm e }$ (60MHz--90MHz), the
characteristic peak intensities ($I_{{\rm SiH}^*}$, $I_{{\rm H}\alpha^*}$
and $I_{{\rm H}\beta ^*}$) in SiHVHF-PECVD技术 氢化微晶硅 光发射光谱 薄膜学 VHF-PECVD technique, hydrogenated microcrystalline silicon, role of hydrogen, optical emission spectroscopy Project supported by the Natural Science Foundation of Guangdong
Province, China (Grant No 05300378), the State Key Development Program for Basic Research
of China (Grant Nos G2000028202 and G2000028203) and the Program on Natural
Science of Jinan University, Guangzhou, China (Grant No 51204056). 2005-11-25 2005-11-252006-01-05 The role of hydrogen in hydrogenated microcrystalline silicon (μc-Si:H) thin films in deposition processes with very high frequency plasma-enhanced chemical vapour deposition (VHF-PECVD) technique have been investigated in this paper. With in situ optical emission spectroscopy (OES) diagnosis during the fabrication of μc-Si:H thin films under different plasma excitation frequency Ve (60MHz-90MHz), the characteristic peak intensities (IsiH*, IHα* and IHβ* ) in SiH4+H2 plasma and the ratio of (IHα* + IHβ* ) to IsiH* were measured; all the characteristic peak intensities and the ratio (IHα* + IHβ* )/IsiH* are increased with plasma excitation frequency. It is identified that high plasma excitation frequency is favourable to promote the decomposition of SiH4+H2 to produce atomic hydrogen and SiHx radicals. The influences of atomic hydrogen on structural properties and that of SiHx radicals on deposition rate of μc-Si:H thin films have been studied through Raman spectra and thickness measurements, respectively. It can be concluded that both the crystalline volume fraction and deposition rate are enhanced with the increase of plasma excitation frequency, which is in good accord with the OES results. By means of FTIR measurements, hydrogen contents of μc-Si:H thin films deposited at different plasma excitation frequency have been evaluated from the integrated intensity of wagging mode near 640 cm^-1. The hydrogen contents vary from 4% to 5%, which are much lower than those of μc-Si:H films deposited with RF-PECVD technique. This implies that μc-Si:H thin films deposited with VHF-PECVD technique usually have good stability under light-soaking. 相似文献
9.
This paper reports that the optical emission spectroscopy (OES) is
used to monitor the plasma during the deposition process of
hydrogenated microcrystalline silicon films in a very high frequency
plasma enhanced chemical vapour deposition system. The OES
intensities (SiH\sj{*}, H微晶硅 VHF-PECVD 发射光谱学 薄膜物理学 microcrystalline silicon,
VHF-PECVD, optical emission spectroscopy 2005-11-09 2005-11-092005-12-12 This paper reports that the optical emission spectroscopy (OES) is used to monitor the plasma during the deposition process of hydrogenated microcrystalline silicon films in a very high frequency plasma enhanced chemical vapour deposition system. The OES intensities (Sill^*, H^* and H^*β) are investigated by varying the deposition parameters. The result shows that the discharge power, silane concentrations and substrate temperature affect the OES intensities. When the discharge power at silane concentration of 4% increases, the OES intensities increase first and then are constant, the intensities increase with the discharge power monotonously at silane concentration of 6%. The SiH^* intensity increases with silane concentration, while the intensities of H^*α and H^*β increase first and then decrease. When the substrate temperature increases, the SiH^* intensity decreases and the intensities of H^*α and H^*β are constant. The correlation between the intensity ratio of IH^*α/ISiH^* and the crystalline volume fraction (Xc) of films is confirmed. 相似文献
10.
Cluster-assisted generation of multicharged ions in nanosecond laser ionization of carbon bisulfide clusters at 1064nm 下载免费PDF全文
The photoionization of seeded carbon bisulfide molecular beam by a
1064\,nm nanosecond Nd-YAG laser with intensities varying from
$0.8\times10^{11}$ to $5.6\times10^{11}$\,W/cm$^{2}$ have been
studied by time-of-flight mass spectrometry. Multiply charged ions
of S$^{q + }$ ($q$ = 2--6) and C$^{q +}$ ($q$ = 2--4) with kinetic
energy of hundreds of electron volts have been observed, and there
are strong experimental evidences indicating that those multicharged
ions originate from the ionization of CS$_{2}$ neat clusters in the
beam. An electron recolliding ionization model is proposed to
explain the appearance of those multiply charged atomic ions under
such low laser intensities. 相似文献
11.
Wen-Ji Shen 《中国物理 B》2022,31(7):76102-076102
Solid H$_{2}$S as the precursor for H$_{3}$S with incredible superconducting properties under high pressure, has recently attracted extensive attention. Here in this work, we propose two new phases of H$_{2}$S with $P$4$_{2}/n$ and $I$4$_{1}/a$ lattice symmetries in a pressure range of 0 GPa-30 GPa through first-principles structural searches, which complement the phase transition sequence. Further an $ab initio$ molecular dynamics simulation confirms that the molecular phase $P2/c$ of H$_{2}$S is gradually dissociated with the pressure increasing and reconstructs into a new $P$2$_{1}/m$ structure at 160 GPa, exhibiting the superconductivity with $T_{\rm c}$ of 82.5 K. Our results may provide a guidance for the theoretical study of low-temperature superconducting phase of H$_{2}$S. 相似文献
12.
High density gas state at water/graphite interface studied by molecular dynamics simulation 下载免费PDF全文
In this paper molecular dynamics simulations are performed to study the accumulation behaviour of N2 and H2 at water/graphite interface under ambient temperature and pressure. It finds that both N2 and H2 molecules can accumulate at the interface and form one of two states according to the ratio of gas molecules number to square of graphite surface from our simulation results: gas films (pancake-like) for a larger ratio and nanobubbles for a smaller ratio. In addition, we discuss the stabilities of nanobubbles at different environment temperatures. Surprisingly, it is found that the density of both kinds of gas states can be greatly increased, even comparable with that of the liquid N2 and liquid H2. The present results are expected to be helpful for the understanding of the stable existence of gas film (pancake-like) and nanobubbles. 相似文献
13.
Absolute optical oscillator strength density and double differential cross section spectra of CO below 120 eV are determined by fast electron impact. Some peaks above the first ionization threshold stand out as the momentum transfer square K2 increases. The doubly excited Rydberg states converging to C 2∑^+, D ^2∏, and F ^2∏ states of CO^+, respectively, are confirmed in our spectra. Another peak at around 32eV is assigned to the transition of (3σ)^-1(2π)^1^1∏←X^1∑^+. 相似文献
14.
This paper studies the isotopic effect of Cl2+ rovibronic spectra in the A2Πu(Ω=1/2) X 2Πg(Ω= 1/2) system.Based on the experimental results of the molecular constants of 35 Cl2+,it calculates the vibrational isotope shifts of the(2,7) and(3,7) band between the isotopic species 35 Cl+2,35 Cl 37 Cl+and 37 Cl2+,and estimates the rotational constants of both A 2 Π u and X 2 Π g states for the minor isotopic species 35 Cl 37 Cl+and 37 Cl2+.The experimental results of the spectrum of 35 Cl 37 Cl+(3,7) band proves the above mentioned theoretical calculation.The molecular constants and thus resultant rovibronic spectrum for 37 Cl2+ were predicted,which will be helpful for further experimental investigation. 相似文献
15.
Studies on heteronuclear diatomic molecular dissociation energies using algebraic energy method 总被引:1,自引:0,他引:1 下载免费PDF全文
The algebraic energy method (AEM) is applied to the study of
molecular dissociation energy $D_e$ for 11 heteronuclear diatomic
electronic states: $a^3\Sigma^+$ state of NaK, $X^2\Sigma^+$ state
of XeBr, $X^2\Sigma^+$ state of HgI, $X^1\Sigma^+$ state of LiH,
$A^3\Pi(1)$ state of ICl, $X^1\Sigma^+$ state of CsH, $A(^3\Pi_1)$
and $B0^+(^3\Pi)$ states of ClF, $2^1\Pi$ state of KRb,
$X^1\Sigma^+$ state of CO, and $c^3\Sigma^+$ state of NaK molecule.
The results show that the values of $D_e$ computed by using the AEM
are satisfactorily accurate compared with experimental ones. The AEM
can serve as an economic and useful tool to generate a reliable
$D_e$ within an allowed experimental error for the electronic states
whose molecular dissociation energies are unavailable from the
existing literature. 相似文献
16.
Computational simulation of ionization processes in single-bubble and multi-bubble sonoluminescence 下载免费PDF全文
Jin-Fu Liang 《中国物理 B》2022,31(11):117802-117802
The most recent spectroscopic studies of moving-single bubble sonoluminescence (MSBSL) and multi-bubble sonoluminescence (MBSL) have revealed that hydrated electrons (e$_{{\rm aq}}^{-}$) are generated in MSBSL but absent in MBSL. To explore the mechanism of this phenomenon, we numerically simulate the ionization processes in single- and multi-bubble sonoluminescence in aqueous solution of terbium chloride (TbCl$_{3}$). The results show that the maximum degree of ionization of single-bubble sonoluminescence (SBSL) is approximately 10000 times greater than that of MBSL under certain special physical parameters. The hydrated electrons (e$_{{{\rm aq}}}^{-}$) formed in SBSL are far more than those in MBSL provided these electrons are ejected from a bubble into a liquid. Therefore, the quenching of e$_{{{\rm aq}}}^{-}$ to SBSL spectrum is stronger than that of the MBSL spectrum. This may be the reason that the trivalent terbium [Tb(III)] ion line intensities from SBSL in the TbCl$_{3}$ aqueous solutions with the acceptor of e$_{{{\rm aq}}}^{-}$ are stronger than those of TbCl$_{3}$ aqueous solutions without the acceptor of e$_{{{\rm aq}}}^{-}$. Whereas the Tb(III) ion line intensities from MBSL are not variational, which is significant for exploring the mechanism behind the cavitation and sonoluminescence. 相似文献
17.
Investigation of the transfer ionization process in collisions of partially stripped ions on He 下载免费PDF全文
In this paper a projectile ion-recoil ion coincidence
technique is used to investigate the transfer ionization processes
in collisions of 0.22--6.30~MeV C^{q + } ions and 0.25--6.35~MeV
O^{q + } ions (q=1, 2, 3, 4) with the He atom separately. The cross
section ratio f of transfer ionization to single electron transfer
is measured, and the dependence of f on both charge state q and
energy E of the projectiles is investigated. The
electron-structure and the mechanisms leading to transfer ionization
affect the dependence of f on q and E. Our measurements, along
with other data published previously, suggest a similar dependence
of f on charge state and energy of projectile for partially
stripped ions over a large energy range. The maximum value of f is
approximately 0.17q^{0.60}; the energy corresponding to maximum
f is about 160q^{0.60}~keV/u. 相似文献
18.
The ionization spectrum of sulfur dioxide has been successfully studied by using the symmetry-adapted-cluster configuration-interaction (SAC-CI) general-R and SD-R methods and the basis set correlation-consistent polarized valence triple-zeta (cc-pVTZ). The SAC-CI general-R method reproduces the experimental spectrum well for both the main peaks and the satellite peaks of ionization spectrum of SO2. The sequence of ionic states corresponding to main peaks of SO2 has been re-determined according to the SAC-CI conclusions and it is reordered as X^2A1, A^2B2, B2A2, C^2B1,D^2A1, E^2B2 and F^2A1. Besides, the equilibrium structures and adiabatic ionization potentials (AIPs) of ionic states of main peaks of SO2 are calculated by using the SAC-CI SD-R method. 相似文献
19.
In this paper, a rotational invariant of interaction energy between two biaxial-shaped molecules is assumed and in the mean field approximation, nine elastic constants for simple distortion patterns in biaxial nematics are derived in terms of the thermal average (Dmn^(l)) (Dm'n'^(l')), where Dmn^(l) is the Wigner rotation matrix. In the lowest order terms, the elastic constants depend on coefficients Γ,Γ', λ, order parameters Q0 = Q0(D00^(2)) +Q2(D02^(2)+D0-2^(2)) and Q2 = Q0(D20^(2)) + Q2(D22^(2)+D2-2^(2)). Here Γ and Γ' depend on the function form of molecular interaction energy vj′j″j (τ12) and probability function fk′k″k (τ12), where r12 is the distance between two molecules, and λ is proportional to temperature. Q0 and Q2 are parameters related to multiple moments of molecules. Comparing these results with those obtained from Landau-de Gennes theory, we have obtained relationships between coefficients, order parameters used in both theories. In the special case of uniaxial nematics, both results are reduced to a degenerate case where K11=K33. 相似文献
20.
Zhi-Gang Wang 《理论物理通讯》2021,73(6):65201
In this article, we construct the color-singlet-color-singlet type currents and the color-singlet-colorsinglet-color-singlet type currents to study the scalar D*■*, D*D* tetraquark molecular states and the vector D*D*■*, D*D*D* hexaquark molecular states with the QCD sum rules in details. In calculations, we choose the pertinent energy scales of the QCD spectral densities with the energy scale formula ■for the tetraquark and hexaquark molecular states respectively in a consistent way. We obtain stable QCD sum rules for the scalar D*■*, D*D*tetraquark molecular states and the vector D*D*■* hexaquark molecular state, but cannot obtain stable QCD sum rules for the vector D*D*D* hexaquark molecular state. The connected(nonfactorizable)Feynman diagrams at the tree level(or the lowest order) and their induced diagrams via substituting the quark lines make positive contributions for the scalar D*D* tetraquark molecular state, but make negative or destructive contributions for the vector D*D*D* hexaquark molecular state. It is of no use or meaningless to distinguish the factorizable and nonfactorizable properties of the Feynman diagrams in the color space in the operator product expansion so as to interpret them in terms of the hadronic observables, we can only obtain information about the short-distance and long-distance contributions. 相似文献