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1.
2.
The sound velocities in GeS2 glass have been measured by means of ultrasonic interferometry as a function of temperature or pressure up to 1.8 kbar. The bulk modulus Ks = 117.6 kbar and shear modulus G = 60.60 kbar were obtained for GeS2 glass at 15°C and 1 atm. The temperature derivatives of both sound velocities and elastic moduli are negative :
(1?T)
p =
?1.54 × 10?4 kmsec
°C,
(1?T)
p =
?1.27× 10?4 kmsec
°C and
(?Ks?T)
p =
?1.27 × 10?2kbar°C
,
(?G?T)
p = ?1.23 × 10?2 kbar/°C,
(?Y?T)
p = ?2.93 × 10?2 their pressure derivatives are positive:
(1?P)
T = 4.43× 10?2km/kbar,
(1?P)
T =
0.633 × 10?2kmkbar
and (?Ks?P0)T=6.81,
(?G?P)T
= 1.03, (?Y?TT= 3.57. The Grüneisen parameter, γth= 0.298, and the second Grüneisen parameter, δs = 3.27, have also been calculated from these data. The elastic behavior of GeS2 glass has proved to be normal despite the structural similarity among the tetrahedrally coordinated SiO2, GeO2 and GeS2 glasses.  相似文献   

3.
The rotational spectrum of methylene cyanide has been measured up to J = 62 and a total of 82 b-type transitions have been obtained. These data have been analyzed with a semirigid rotor Hamiltonian to give accurate rotational and centrifugal distortion constants. The rotational constants are (in MHz) A = 20882.7537 ≠ 0.017, B = 2942.3003. ≠ 0.0031, C = 2616.7225 ≠ 0.0031 The quartic centrifugal distortion constants are (in MHz)
ΔJ (1.855455 ≠ 0.014) x 10?3 ΔJK = (?6.79218 ≠ 0.027) x 10?2
ΔK (8.621628 ≠ 0.013) x 10?1 δJ = (4.892607 ≠ 0.016) x 10?4
δK = (6.7501 ≠ 0.29) x 10?3
The uncertainties are twice the standard deviations in the constants obtained from the least squares analysis, and represent approximately 95% confidence limits.  相似文献   

4.
The production of a strange dibaryonic system called H+1 (M = 2.13 GeV/c2, S = ?1), has been studied with a missing mass spectrometer, at the CERN Proton Synchrotron, in the reaction K?d → π?H+1 and in the line-reversed reaction π+d → K+H+1 between 0.9 and 1.4 GeV/c.The reactions
K?d → π?X+
,
πdK+X+
,have been studied in a missing mass spectrometer at CERN. The experiment (PS159) is well adapted to search for a signal in the missing mass X+ (B = 2, S = ?1) produced in the backward c.m.s. direction, between 2.0 and 2.3 GeV/c2. The two reactions have been analysed at three different beam settings: 1.4, 1.06 and 0.92 GeV/c for reaction (1) and 1.4, 1.2 and 1.06 GeV/c for reaction (2).  相似文献   

5.
The 0-0, 1-1, 2-2, and 3-3 bands of the A2Π-X2Σ+ transition of the tritiated beryllium monohydride molecule have been observed at 5000 Å in emission using a beryllium hollow-cathode discharge in a He + T2 mixture. The rotational analysis of these bands yields the following principal molecular constants.
A2Π:Be = 4.192 cm?1; re = 1.333 A?
X2Σ:Be = 4.142 cm?1; re = 1.341 A?
ωe′ ? ωe″ = 16.36 cm?1; ωe′Xe′ ? ωe″Xe″ = 0.84 cm?1
From the pure electronic energy difference (EΠ - EΣ)BeT = 20 037.91 ± 1.5 cm?1 and the corresponding previously known values for BeH and BeD, the following electronic isotope shifts are derived
ΔEei(BeH?BeT) = ?4.7 ≠ 1.5cm1, ΔEei(BeH?BeT) = ?1.8 ≠ 1.5cm1
and related to the theoretical approach given by Bunker to the problem of the breakdown of the Born-Oppenheimer approximation.  相似文献   

6.
It is shown that for spinorial charges Q(L))α (α = 1, 2, L = 1, …, S) satisfying the commutation relations
{Q(L)α, Q(M)β} = εαβaLMQ,
{Q(L)α, Q(M)+β} = cσμαβPμδLM,
[Q(L))α, Pμ] = 0,
where Q is a scalar charge commuting with the spinor charges as well aswith the energy- momentum vector Pμ, there can exist several different multiplets for free massive scalar and spinor fields.  相似文献   

7.
The microwave spectrum of the molecular transient disulfur monoxide, S2O, has been reexamined and the microwave measurements have been extended into the millimeterwave region. From the present data, the following ground-state rotational constants and quartic distortion constants have been obtained (MHz):
A = 41915.44, B = 5059.07, C = 4507.19
δJ = 1.895 X 10?, δJK = ?3.192 X 10?2,δK = 1.197 X 100
δJ = 3.453 X 10?4 and δK = 1.223 X 10?2
The centrifugal distortion constants obtained from the rotational spectrum are used to discuss the vibrational spectrum of disulfur monoxide.  相似文献   

8.
The infrared spectrum of yttrium monoiodide has been excited in an electrodeless microwave discharge and explored between 2500 and 12 000cm?1 with a high-resolution Fourier transform spectrometer. A unique system is observed (ν00 = 9905.520 cm?1), which we attribute to a 1Π1Σ transition and an extensive analysis is made. Rovibrational constants are obtained for both states mainly from a simultaneous multiband fitting. This procedure is applied to the whole set of 2231 observed line wavenumbers in the 1-0, 0-0, and 0–1 bands, yielding a final weighted standard deviation of 0.0038 cm?1. Furthermore, a partial analysis of the 2-0 and 3-1 bands is performed. The following equilibrium constants are derived (cm?1):
ω′e=192.210 ω′ex′e=0.463
B′e=0.0399133 α′e=0.0001150
ω″e=215.815 ω″ex″e=0.514
B″e=0.0422163 α″e=0.0001125
High-order constants Dv and Hv are also calculated for the various vibrational levels (v′ = 0, 1, 2, 3; v″ = 0, 1).  相似文献   

9.
The investigation of the emission infrared spectrum of P2 was performed with a high resolution Fourier spectrometer. Two new electronic systems were attributed to b3Πgw3Δu and A1ΠgW1Δu transitions. The molecular parameters are obtained by a complete fitting procedure. The main equilibrium constants of the new states are (in cm?1):
ω3Δu Te = 243228.07 ωe = 591.3 ωeXe = 2.5
Be = 0.256040 δe = 0.001409 De = 19.0 X 10?8
W1ΔuTe = 31096.64 We = 627.206 WeXe = 2.331
Be = 0.2628 δe = 0.0014 De = 23 X 10?8
  相似文献   

10.
We prove that the topological closure of the cone K of positive elements in the algebra of test functions is the same for several topologies (K?τo° = K?τ). Further we show that all elements of the closure of K are of the form
I=1f(i)1f(i) with f(i)?L?
and the sum converges. Applying these results, we give a characterization of the elements of K?τo too.  相似文献   

11.
Molecular constants of the first E 0+ ion-pair state of IBr vapor have been determined using polarization-labeling spectroscopy applied to the sequential transitions E 0+B′ 0+X 0+, while the second f 0+ ion-pair state is reported and characterized for the first time. A least-squares, simultaneous analysis of data for the I79Br and I81Br isotopes gives the following constants (in cm?1) for I79Br:
E state: Te = 39487.32(12), ωe = 119.518(21), ωeξe = 0.2109(12)
,
ωeye = ? 2.34(22) × 10?4, Be = 2.9701(14) × 10?2
,
αe = 5.43(59) × 10?5, and γe = ? 6.8(16) × 10?7
.
F state: Te = 45382.58(17), ωe = 128.805(66), ωeξe = 0.3630(69)
,
ωeye = ? 9.7(22) × 10?4, Be = 3.0073(30) × 10?2, and αe = 8.52(48) × 10?5
. Preliminary data for the first Ω = 1 ion-pair state, accessed in the sequence 1(3P2) ← A(Ω = 1) ← X 0+, indicate that Te is ?30 cm?1 higher in energy than that of the E state.  相似文献   

12.
Concentration dependent diffusion coefficients for 45Ca2+ and 85Sr2+ in purified KCl were measured using a sectioning method. KCl was purified by an ion exchange — Cl2?HCl process and the crystals grown under 16 atmosphere of HCl. The tracers were purified on small disposable ion exchange columns to remove precessor and daughter impurities prior to use in a diffusion anneal. Isothermal diffusion anneals were made in the temperature range from 451% to 669%C. At temperatures above 580%C (the lowest melting eutectic in this system) diffusion was from a vapor source: below 580%C surface depositied sources were used. The saturation diffusion coefficients. enthalpies and entropies of impurity-vacancy associations were calculated using the common ion model for simultaneous diffusion of divalent ions in alkali halides. In KCl the saturation diffusion coefficients DS(ca) and Ds(Sr) are given by
Ds(Ca) = 9.93 × 10?5 exp(?0.592 eVkT)cm2sec
(1) and
Ds(Sr) = 1.20 × 10?3 exp(?0.871 eVkT)cm2sec
(2) for calcium and strontium, respectively. The Gibbs free energy of association of the impurity vacancy complex in KCl for calcium can be represented by
Δg(Ca) = ?-0.507 eV + (2.25 × 10?4eV%K)T
(3) and that for strontium by
Δg(Sr) = ?0.575 eV + (2.90 × 10?4eV%K)T
. (4)  相似文献   

13.
The transverse spin pair correlation function pxn=<SxmSxm+n>=<SxmSxm+n> is calculated exactly in the thermodynamic limit of the system described by the one-dimensional, isotropic, spin-12, XY Hamiltonian
H=?2Jl=1N(SxlSxl+1+SylSyl+1)
. It is found that at absolute zero temperature (T = 0), the correlation function ρxn for n ≥ 0 is given by
ρx2p=142π2pΠj=1p?14j24j2?12p?2jif n=2p
,
ρx2p+1142π2p+1Πj=1p4j24j2?12p+2jif n=2p+1
, where the plus sign applies when J is positive and the minus sign applies when J is negative. From these the asymptotic behavior as n → ∞ of |?xn| at T = 0 is derived to be xn| ~ an with a = 0.147088?. For finite temperatures, ρxn is calculated numerically. By using the results for ?xn, the transverse inverse correlation length and the wavenumber dependent transverse spin pair correlation function are also calculated exactly.  相似文献   

14.
It is proved that the quantum mechanical Hamiltonian H = Σi=1N (p2 + m2)12 ? κ Σi>j|xi ? xj|?1 for bosons (resp, fermions) is bounded from below if Ncbκ?1 (resp. N ≤ cfκ?32). H is unbounded from below if Ncblκ?1 (resp. N ≥ cflκ?32). The constants cb and cbl (resp. cf and cfl) differ by about a factor 2 (resp. 4).  相似文献   

15.
A rotational analysis of the satellite bands of the β system of ZrO gives the splittings in the triplet states. For the lowest triplet state X3Δ, these splittings are:
δF1,2 = 287.9 ± 0.1 cm?1,
δF2,3 = 337.6 ± 0.4 cm?1.
  相似文献   

16.
For the first time, the reactions π+p→K++ and K?p→π?+ have been studied in the same apparatus. This has been done at an adequately high momentum (10.1 GeV/c) to allow a check of the prediction of exchange degeneracy, that the differential cross sections should be converging at high energy. We have measured the cross section for momentum transfers t between tmin and t = ?0.3 (GeV/c)2. We find that for both reactions the differential cross section shows an exponential fall, with no deviations right in to t =tmin (where some other experiments have shown a dip in the cross section). Furthermore, we find the magnitude of the differential cross sections to be closely similar at t = 0, with a ratio
R=(dσdt)t=0(K?p→π?+)(dσdt)t=0+pK++
However, the slope for the positive reaction is about 19% steeper than that for the negative reaction.  相似文献   

17.
We study in detail the Lie-algebraical properties of the quantization condition for spinor fields
[a+i,a?j],a±i = ±2δija±j
.It turns out that the parafermi statistics is one particular solution of this relation: it is the minimal rank simple Lie algebra generated by the operators a±i entering into the above relation. We point out some other solutions.  相似文献   

18.
A rotational assignment of approximately 80 lines with Ka′ = 0, 1, 2, 3, and 4 has been made of the 593 nm 2A12B2 band of NO2 using cw dye laser excitation and microwave optical double-resonance spectroscopy. Rotational constants for the 2B2 state were obtained as A = 8.52 cm?1, B = 0.458 cm?1, and C = 0.388 cm?1. Spin splittings for the Ka′ = 0 excited state levels fit a simple symmetric top formula and give (?bb + ?cc)2 = ?0.0483 cm?1. Spin splittings for Ka′ = 1 (N′ even) are irregular and are shown to change sign between N′ = 6 and 8. Assuming that the large inertial defect of 4.66 amu Å2 arises solely from A, a structure for the 2B2 state is obtained which gives r (NO) = 1.35 A? and an ONO angle of 105°. Alternatively, weighting the three rotational constants equally gives r = 1.29 A? and θ = 118°.  相似文献   

19.
In the terminology of [4] it is shown that a normalized positive map ? from a C1-algebra A into M2 is a sum ?=ψ12, where ψ1 is completely positive and ψ2 is completely copositive, if and only if for all a?1 in A the normalized positive map
?a=?(a2)?12?(a·a)?(a2)?12
satisfies the “strong Kadison inequality” of S.L. Woronowicz ([4]). p. 178).  相似文献   

20.
The B?X? band system of NO2, 2Σ?gu) ← 2A1, has been measured in absorption in a neon matrix at 6 K, using 15NO2 and N18O2 in addition to the normal isotope. The spectrum consists essentially of a single, long progression of bands terminating on successive levels of the bending mode in the upper state. Transitions to odd- and even-v2′ states occur with a uniform intensity distribution indicating that the rotation of the bent ground state of NO2 about its near-prolate axis is hindered in the matrix. The observations strongly suggest that the top axis of the molecule coincides with a C2 axis of neon crystals in the polycrystalline matrix. Relative to the vapor absorption the matrix spectrum is red shifted by about 150 cm?1, the crystal field parameter V2 and principal constants of the B? state of 14N16O2 in neon being
T010 14 571 cm?1: x22, ?0.3 cm?1;
w2 460.2 cm?1: V2, 80 cm?1.
  相似文献   

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