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1.
TheY2Σ+–X2Πinear-infrared electronic transition of CuO was observed at high resolution for the first time. The spectrum was recorded with the Fourier transform spectrometer associated with the McMath–Pierce Solar Telescope at Kitt Peak. The excited CuO molecules were produced in a low pressure copper hollow cathode sputter with a slow flow of oxygen. Constants for theY2Σ+states of CuO are:T0= 7715.47765(54) cm−1,B= 0.4735780(28) cm−1,D= 0.822(12) × 10−6cm−1,H= 0.46(10) × 10−10cm−1, γ = −0.089587(42) cm−1, γD= 0.1272(79) × 10−6cm−1,bF= 0.12347(22) cm−1, andc= 0.0550(74) cm−1. ImprovedX2Πiconstants are also presented.  相似文献   

2.
Superstring theory in d = 10 dimensions after Calabi—Yau compactification yields a minimum low-energy gauge group SU(3)C × SU(2)L × U(1)Y × U(1)E. The low-energy theory includes particles with the quantum numbers of 27 representations of E6, each of which contains an extra neutrino νc conventionally called a “right-handed neutrino”. The contributions of ν and νc to through Z0 and ZE mixing is calculated. Small contributions are found of the new right-handed neutrino and of the superstring boson ZE to σ(e+e → γ + nothing).  相似文献   

3.
The 2ν3(A1) band of 12CD3F near 5.06 μm has been recorded with a resolution of 20–24 × 10−3 cm−1. The value of the parameter (αB − αA) for this band was found to be very small and, therefore, the K structure of the R(J) and P(J) manifolds was unresolved for J < 15 and only partially resolved for larger J values. The band was analyzed using standard techniques and values for the following constants determined: ν0 = 1977.178(3) cm−1, B″ = 0.68216(9) cm−1, DJ = 1.10(30) × 10−6 cm−1, αB = (B″ − B′) = 3.086(7) × 10−3 cm−1, and βJ = (DJDJ) = −3.24(11) × 10−7 cm−1. A value of αA = (A″ − A′) = 2.90(5) × 10−3 cm−1 has been obtained through band contour simulations of the R(J) and P(J) multiplets.  相似文献   

4.
The pure rotational spectrum of CH2F2 was recorded in the 20–100 cm−1 spectral range and analyzed to obtain rotation and centrifugal distortion constants. Analysis of the data yielded rotation constants: A = 1.6392173 ± 0.0000015, B = 0.3537342 ± 0.00000033, C = 0.3085387 ± 0.00000027, τaaaa = −(7.64 ± 0.46) × 10−5, τbbbb = −(2.076 ± 0.016) × 10−6, τcccc = −(9.29 ± 0.12) × 10−7, T1 = (4.89 ± 0.20) × 10−6, and T2 = −(1.281 ± 0.016) × 10−6cm−1.  相似文献   

5.
Using a Fourier transform spectrometer, we have recorded the spectra of ozone in the region of 4600 cm−1, with a resolution of 0.008 cm−1. The strongest absorption in this region is due to the ν1+ ν2+ 3ν3band which is in Coriolis interaction with the ν2+ 4ν3band. We have been able to assign more than 1700 transitions for these two bands. To correctly reproduce the calculation of energy levels, it has been necessary to introduce the (320) state which strongly perturbs the (113) and (014) states through Coriolis- and Fermi-type resonances. Seventy transitions of the 3ν1+ 2ν2band have also been observed. The final fit on 926 energy levels withJmax= 50 andKmax= 16 gives RMS = 3.1 × 10−3cm−1and provides a satisfactory agreement of calculated and observed upper levels for most of the transitions. The following values for band centers are derived: ν01+ ν2+ 3ν3) = 4658.950 cm−1, ν0(3ν1+ 2ν2) = 4643.821 cm−1, and ν02+ 4ν3) = 4632.888 cm−1. Line intensities have been measured and fitted, leading to the determination of transition moment parameters for the two bands ν1+ ν2+ 3ν3and ν2+ 4ν3. Using these parameters we have obtained the following estimations for the integrated band intensities,SV1+ ν2+ 3ν3) = 8.84 × 10−22,SV2+ 4ν3) = 1.70 × 10−22, andSV(3ν1+ 2ν2) = 0.49 × 10−22cm−1/molecule cm−2at 296 K, which correspond to a cutoff of 10−26cm−1/molecule cm−2.  相似文献   

6.
The ν3±1 perpendicular band of 14NF3 ( cm−1) has been studied with a resolution of 2.5 × 10−3 cm−1, and 3682 infrared (IR) transitions (Jmax=55, Kmax=45) have been assigned. These transitions were complemented by 183 millimeterwave (MMW) rotational lines (Jmax=25, Kmax=19) in the 150–550 GHz region (precision 50–100 kHz). The kl=+1 level reveals a strong A1/A2 splitting due to the l(2,2) rotational interaction (q=−4.05 × 10−3 cm−1) while the kl=−2 and +4 levels exhibit small A1/A2 splittings due to l(2,−4) and l(0,6) rotational interactions. All these splittings were observed by both experimental methods. Assuming the v3=1 vibrational state as isolated, a Hamiltonian model of interactions in the D reduction, with l(2,−1) rotational interaction (r=−1.96 × 10−4 cm−1) added, accounted for the observations. A set of 26 molecular constants reproduced the IR observations with σIR=0.175 × 10−3 cm−1 and the MMW data with σMMW=134 kHz. The Q reduction was also performed and found of comparable quality while the QD reduction behaved poorly. This may be explained by a predicted Coriolis interaction between v3=1 and v1=1 (A1, 1032.001 cm−1) which induces a slow convergence of the Hamiltonian in the QD reduction but has no major influence on the other reductions. The experimental equilibrium structure could be calculated as: re(N–F)=1.3676 Å and (FNF)=101.84°.  相似文献   

7.
The 2ν3 overtone (A1E) and the ν1 + ν3 (E) combination bands of the oblate symmetric top 14NF3 were studied by FTIR spectroscopy with a resolution of 2.5 × 10−3 cm−1. Nearly 500 lines up to Kmax/Jmax = 30/43 were observed for the weak A1 component reaching the v3 = 20 substate (1803.1302 cm−1), the majority of which corresponded to reinforced K = 3p-type transitions. For the strong E component reaching the v3 = 2±2 substate (1810.4239 cm−1), about 3550 transitions were assigned up to Kmax/Jmax = 65/69, favoring a clear observation of the ℓ(4, −2) and ℓ(4, 4) splittings within the kℓ = −2 and +4 sublevels, respectively. The two v3 = 2 substates are linked by the ℓ(2, 2)- and ℓ(2, −1)-type interactions, providing severe crossings, respectively, at K′ = 6 and near K′ = 24 on the v3 = 2+2 side. A model working in the D-reduction and including all these ℓ-type interactions could reproduce together 3695 nonzero weighted experimental data (NZW) through 33 free parameters with a standard deviation of σ = 0.357 × 10−3  cm−1. As for the ν1 + ν3 (E) combination band, about 3690 lines were assigned up to Kmax/Jmax = 45/55. Its v1 = v3 = 1 upper state (1931.577 5 cm−1) was treated using the same model recently applied to the v3 = 1 (E, 907.5413 cm−1) state. It yielded 21 free parameters through 3282 NZW experimental data, adjusted with σ = 0.344 × 10−3  cm−1 in the D-reduction. For the two excited states, the small and unobserved ℓ(0, 6) interaction was tested as useless. To confirm the adequacy of the vibrationally isolated models used, some other reductions of the Hamiltonian were tried. For the v3 = 2 state, the D-, L-, and LD-reductions led to similar σ’s, while the Q one was not successful. For the v1 = v3 = 1 state, the D- and Q-reductions gave comparable σ’s, while the QD-reduction was not as good. The corresponding unitary equivalence relations are generally more nicely fulfilled for the v3 = 2 state than for the v1 = v3 = 1 state. The three derivable anharmonicity constants in cm−1 are x33 = −4.1528, g33 = +1.8235 and x13 = −7.9652.  相似文献   

8.
The Ag2O–TiO2–SiO2 glasses were prepared by Ag+/Na+ ion-exchange method from Na2O–TiO2–SiO2 glasses at 380–450 °C below their glass transition temperatures (Tg), and their electrical conductivities were investigated as functions of TiO2 content and the ion-exchange ratio (Ag/(Ag+Na)). In a series of glasses 20R2xTiO2·(80−x)SiO2 with x=10, 20, 30 and 40 in mol%, the electrical conductivities at 200 °C of the fully ion-exchanged glasses of R=Ag were in the order of 10−5 or 10−4 S cm−1 and were 1 or 2 orders of magnitude higher than those of the initial glasses of R=Na. The glass of x=30 exhibited the highest increase of conductivity from 3.8×10−7 to 1.3×10−4 S cm−1 at 200 °C by Ag+/Na+ ion exchange among them. When the ion-exchange ratio was changed in 20R2O·30TiO2·50SiO2 system, the electrical conductivity at 200 °C exhibited a minimum value of 7.6×10−8 S cm−1 around Ag/(Ag+Na)=0.3 and increased steeply in the region of Ag/(Ag+Na)=0.5–1.0. When the ion-exchange temperature was changed from 450 to 400 °C, the conductivity of the ion-exchanged glass of x=30 decreased. The infrared spectroscopy measurement revealed that the ion-exchange temperature of 450 °C induced a structural change in the glass of x=30. The Tg of the fully ion-exchanged glass of x=30 was 498 °C. It was suggested that the incorporated silver ions changed the average coordination number of titanium ions to form higher ion-conducting pathway and resulted in high conductivity in the titanosilicate glasses.  相似文献   

9.
The high-resolution infrared spectrum of HCF3 was studied in the ν6 fundamental (near 500 cm−1) and in the 2ν6 overtones (near 1000 cm−1) regions. The present study reports on the analysis of the hot bands in the ν6 region, as well as the first observation and assignment of the 2ν62 perpendicular band. Using ν6, 2ν6±2ν6±1 and 2ν62 experimental wavenumbers, accurate coefficients C0 and DK0 of the K-dependent ground-state energy terms were obtained, using the so-called “loop method.” Ground-state energy differences Δ(K,J)=E0(K,J)−E0(K−3,J) were obtained for K=3–30. A least-squares fit of 81 such differences gave the following results (in cm−1): C0=0.1892550(15); DK0=2.779(26) × 10−7.  相似文献   

10.
We examine the reach of a Beta-beam experiment with two detectors at carefully chosen baselines for exploring neutrino mass parameters. Locating the source at CERN, the two detectors and baselines are: (a) a 50 kton iron calorimeter (ICAL) at a baseline of around 7150 km which is roughly the magic baseline, e.g., ICAL@INO, and (b) a 50 kton Totally Active Scintillator Detector at a distance of 730 km, e.g., at Gran Sasso. We choose 8B and 8Li source ions with a boost factor γ of 650 for the magic baseline while for the closer detector we consider 18Ne and 6He ions with a range of Lorentz boosts. We find that the locations of the two detectors complement each other leading to an exceptional high sensitivity. With γ=650 for 8B/8Li and γ=575 for 18Ne/6He and total luminosity corresponding to 5×(1.1×1018) and 5×(2.9×1018) useful ion decays in neutrino and antineutrino modes respectively, we find that the two-detector set-up can probe maximal CP violation and establish the neutrino mass ordering if sin22θ13 is 1.4×10−4 and 2.7×10−4, respectively, or more. The sensitivity reach for sin22θ13 itself is 5.5×10−4. With a factor of 10 higher luminosity, the corresponding sin22θ13 reach of this set-up would be 1.8×10−5, 4.6×10−5 and 5.3×10−5 respectively for the above three performance indicators. CP violation can be discovered for 64% of the possible δCP values for sin22θ1310−3 (8×10−5), for the standard luminosity (10 times enhanced luminosity). Comparable physics performance can be achieved in a set-up where data from CERN to INO@ICAL is combined with that from CERN to the Boulby mine in United Kingdom, a baseline of 1050 km.  相似文献   

11.
Several elementary reactions of formyl radical of combustion importance were studied using pulsed laser photolysis coupled to transient UV–Vis absorption spectroscopy: HCO → H + CO (1), HCO + HCO → products (2), and HCO + CH3 → products (3). One-pass UV absorption, multi-pass UV absorption as well as cavity ring-down spectroscopy in the red spectral region were used to monitor temporal profiles of HCO radical. Reaction (1) was studied over the buffer gas (He) pressure range 0.8–100 bar and the temperature range 498–769 K. Reactions (2a), (2b), (2c), (3a) and (3b) as well as the UV absorption spectrum of HCO, were studied at 298 and 588 K, and the buffer gas (He) pressure of 1 bar. Pulsed laser photolysis (308, 320, and 193 nm) of acetaldehyde, propionaldehyde, and acetone was used to prepare mixtures of free radicals. The second-order rate constant of reaction (1) obtained from the data at 1 bar is: k1(He) = (0.8 ± 0.4) × 10−10exp(−(66.0 ± 3.4) kJ mol−1/RT) cm3 molecule−1 s−1. The HCO dissociation rate constants measured in this work are lower than those reported in the previous direct work. The difference is a factor of 2.2 at the highest temperature of the experiments and a factor of 3.5 at the low end. The experimental data indicate pressure dependence of the rate constant of dissociation of formyl radical 1, which was attributed to the early pressure fall-off expected based on the theory of isolated resonances. The UV absorption spectrum of HCO was revised. The maximum absorption cross-section of HCO is (7.3 ± 1.2) × 10−18 cm2 molecule−1 at 230 nm (temperature independent within the experimental error). The measured rate constants for reactions (2a), (2b), (2c), (3a) and (3b) are: k2 = (3.6 ± 0.8) × 10−11 cm3 molecule−1 s−1 (298 K); k3 = (9.3 ± 2.3) × 10−11 cm3 molecule−1 s−1(298 and 588 K).  相似文献   

12.
In the experiments on 74Ge(d, pγ)75Ge, a 52.5±0.1 keV γ-ray was found in 75Ge with a half-life of 216±5 ns. From the analysis of the γ-ray spectra the conversion coefficient of the 52.5 keV γ-ray was determined. Then, a new level of is confirmed to exist at 192.5 keV. The reduced transition probabilities of the 52.5 keV transition are deduced to be (6.9+5.6 −2.1) × 10−5 for B(M1) and 31+3 −2 for B(E2) in Weisskopf units.  相似文献   

13.
The glasses with the composition of 37.5Li2O–(25 − x)Fe2O3xNb2O5–37.5P2O5 (mol%) (x = 5,10,15) are prepared, and it is found that the addition of Nb2O5 is effective for the glass formation in the lithium iron phosphate system. The glass–ceramics consisting of Nasicon-type Li3Fe2(PO4)3 crystals with an orthorhombic structure are developed through conventional crystallization in an electric furnace, showing electrical conductivities of 3 × 10− 6 Scm− 1 at room temperature and the activation energies of 0.48 eV (x = 5) and 0.51 eV (x = 10) for Li+ ion conduction in the temperature range of 30–200 °C. A continuous wave Nd:YAG laser (wavelength: 1064 nm) with powers of 0.14–0.30 W and a scanning speed of 10 μm/s is irradiated onto the surface of the glasses, and the formation of Li3Fe2(PO4)3 crystals is confirmed from XRD analyses and micro-Raman scattering spectra. The crystallization of the precursor glasses is considered as new route for the fabrication of Li3Fe2(PO4)3 crystals being candidates for use as electrolyte materials in lithium ion secondary batteries.  相似文献   

14.
This paper reports the spectral properties and energy levels of Cr3+:Sc2(MoO4)3 crystal. The crystal field strength Dq, Racah parameter B and C were calculated to be 1408 cm−1, 608 cm−1 and 3054 cm−1, respectively. The absorption cross sections σα of 4A24T1 and 4A24T2 transitions were 3.74×10−19 cm2 at 499 nm and 3.21×10−19 cm2 at 710 nm, respectively. The emission cross section σe was 375×10−20 cm2 at 880 nm. Cr3+:Sc2(MoO4)3 crystal has a broad emission band with a broad FWHM of 176 nm (2179 cm−1). Therefore, Cr3+:Sc2(MoO4)3 crystal may be regarded as a potential tunable laser gain medium.  相似文献   

15.
Nonlinear optical properties of Fe2O3 nanoparticles were investigated by the signal-beam Z-scan technique with Ar+ and Ne–He lasers. The largest reported effective nonlinear coefficient, n2=−8.07×10−7 cm2/W, was obtained. It is demonstrated that the nonlinear optical response originals from quantum confinement effect.  相似文献   

16.
The electron impact behavior of CO adsorbed on was investigated. The desorption products observed were neutral CO, CO+, and O+. After massive electron impact residual carbon, C/W = 0.15, but not oxygen was also found, suggesting that energetic neutral O, not detected in a mass analyzer must also have been formed. Formation of β-CO, i.e., dissociated CO with C and O on the surface was not seen. The total disappearance cross section varies only slightly with coverage, ranging from 9 × 10 −18 cm2 at low to 5 × 10−18 cm2 at saturation (CO/W = 0.75). The cross section for CO+ formation varies from 4 × 10−22 cm2 at satura to 2 × 10−21 cm2 at low coverage. That for O+ formation is 1.4 × 10−22 cm2 at saturation and 2 × 10−21 cm2 Threshold energies are similar to those found previously [J.C. Lin and R. Gomer, Surf. Sci. 218 (1989) 406] for and CO/Cu1/W(110) which suggests similar mechanisms for product formation, with the exception of β-CO on clean W(110). It is argued that the absence or presence of β-CO in ESD hinges on its formation or absence in thermal desorption, since electron impact is likely to present the surface with vibrationally and rotationally activated CO in all cases; β-CO formation only occurs on surfaces which can dissociate such CO. It was also found that ESD of CO led to a work function increase of the remaining Pd1/W(110) surface of 500 meV, which could be annealed out only at 900 K. This is attributed to surface roughness, caused by recoil momentum of energetic desorbing entities.  相似文献   

17.
An analysis of data on is presented at beam momenta 600 to 1940 MeV/c. There is evidence for an I=1, JPC=2−+ resonance in ηηπ0 with mass M=1880±20 MeV and width 255±45 MeV, decaying strongly to a2(1320)η; it is too strong to be explained as the high mass tail of π2(1670)→a2(1320)η. There is tentative evidence also for weak decays to f0(1500)π. It makes a natural partner to the η2(1860).  相似文献   

18.
《Physics letters. [Part B]》2008,660(5):466-470
A partial-wave analysis of the reaction πpηηπp at 18 GeV/c has been performed on a data sample of approximately 4000 events obtained by Brookhaven experiment E852. The JPC=0−+π(1800) state is observed in the a0(980)η and f0(1500)π decay modes. It has a mass of 1876±18±16 MeV/c2 and a width of 221±26±38 MeV/c2. The JPC=2−+π2(1880) meson is observed decaying through a2(1320)η. It has a mass of 1929±24±18 MeV/c2 and a width of 323±87±43 MeV/c2. Both states are potential candidates for non-exotic hybrid mesons.  相似文献   

19.
Intersubband transitions in quantum well have extremely large oscillator strengths and induce strong nonlinear effects in structures where inversion symmetry is broken, realized by growing AlGaAs quantum wells with asymmetrical A1 gradients. These compositionally asymmetrical multiquantum wells may thus be viewed as giant “quasimolecules” optimized for optimal nonlinearities in the mid infrared. Optical rectification as well as second harmonic generation have been measured in those structures using a continuous CO2 laser. At 10.6 μm the nonlinear coefficients are more than 3 orders of magnitude higher in these samples than for bulk GaAs (i.e. χ0(2) = 5.3 × 10−6m/V, χ2ω(2) = 7.2 × 10−7 m/V) and are in good agreement with theoretical predictions. We present more complex “pseudo-molecules” involving weakly coupled quantum wells. The optical rectification effects in these devices are so large χ0(2) = 1.6 × 10−3 m/V) that application to infrared detection may be envisioned.  相似文献   

20.
The Fourier transform infrared spectrum of monoisotopic SC80Se has been investigated in the ν2, ν3, 2ν2, 2ν3, and ν1 regions with a resolution between 3 and 4 × 10−3 cm−1. In addition, the millimeter-wave spectrum has been studied in the region 150 to 320 GHz, and ground and ν2 = 1 excited state transitions have been measured. Ground state constants, B0 = 2043.285 4(4) MHz and D0 = 146.53(5) Hz, have been determined from a merge of millimeter-wave data and ground state combination differences spanning J values up to 77 and 143, respectively. The band centers ν2 = 352.341 075(9) cm−1 and ν3 = 505.480 06(5)cm−1 have been determined. The rovibrational parameters of numerous overtone and combination levels (ν1νl22ν3) = 0200, 0220, 0310, 0330, 0400, 0420, 0002, and 0003 have been obtained from polynomial analyses whose standard deviations ranged from 0.7 to 3.5 × 10−4 cm−1. The 1000 level, νeff 1435.840 cm−1, is anharmonically perturbed by the 0400 level, with an avoided crossing at J = 55, and W12222 = 0.963 09(1) cm−1. Transitions to both the upper (E+) and lower (E) sublevels of the dyad were observed for 1 ≤ J′ ≤ 117 and 4 ≤ J′ ≤ 171, respectively, and the deperturbed wavenumbers ν1 = 1435.542 76(2) and 4ν02 = 1432.725 00(3) cm−1 were derived. Furthermore, a local crossing of the E and 0420 levels involving l-type resonance was observed at J = 91.  相似文献   

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