Emission spectra in orthorhombic PbCl2 at low temperature

The emission spectra and its time decay in PbCl₂ at low temperature are reported. Three emission bands lying at 3.81 (uv), 2.93 (blue) and 2.60 eV are found for the photo-excitation in the intrinsic absorption region, at 4.2 K. An exponential decay with decay time of 11.4 μs is observed for the uv emission. For the blue emission two kinds of time decay spectra are observed: a second order process below 10 K and an exponential decay above 14 K. The mechanisms of these emission are discussed by taking into account the above results.     

Concepts of probabilistic sets

In the field of pattern recognition or decision making theory, the important subjects are as follows: (1) ambiguity of property of objects, (2) variety of character of objects, (3) subjectivity of observers, (4) evolution of knowledge of observers (i.e. learning). Considering these points, the concept of probabilistic set is proposed. It is based on both probability theory and fuzzy concepts. A probabilistic set on a total space is defined by a point wise measurable function from a parameter space (which is a probability space) to a characteristic space (which is a measurable space). It is shown that the family of all probabilistic sets constitutes a complete pseudo-Boolean algebra. Moment analysis is possible by using a probability measure of the parameter space. Other useful concepts are also mentioned such as probabilistic mappings and expected cardinal numbers.     

Inverse scattering problem for internal waves with finite fluid depth

In this paper, we derive the Bäcklund transformation, an infinite set of conservation laws and the inverse scattering transform of nonlinear equation that describes the internal waves of fluids with finite depth, ø_t + 2øø_x + (C/S)ø_xx = 0, which has been shown before to have N-soliton solutions.     

Hyperfine structure in the à state of PH2 arising from the fermi interaction of 31P

The photoluminescence spectrum of PH₂ excited by a cw dye laser shows resolved ¹³P hyperfine structure for the 0₀₀ level even in the presence of Doppler broadening. The observed splittings give a Femi contact constant for the (0,0,0) òA₁ state of PH₂ of 1.8 ± 0.1 GHz.     

Second-order Coriolis resonance between ν2 and ν5 of CH3F by microwave spectroscopy

The J = 1 ← 0 and J = 2 ← 1 transitions and the l-doubling transitions of J = 2 – 6 of ¹²CH₃F in the ν₂ and ν₅ states were analyzed by taking into account the Coriolis interaction between the two modes. The molecular constants which are derived are: ν₅ - ν₂, 252 412 ± 112; $\text{B}{}_5{}^1$, 25 611.60 ± 0.40; A_ζ5, ?38 772 ± 116; $\text{B}{}_2{}^1$, 25 432.52 ± 0.33; D, 21 838.4 ± 8.2; $\text{q}{}_5{}^1$, 39.58 ± 0.30 MHz; in addition to a few other minor constants. The present result is completely consistent with the recent Raman data of Escribano, Mills, and Brodersen, J. Mol. Spectrosc.61, 249 (1976). Molecular constants in the ν₃ and ν₆ states have also been obtained: B₃, 25 197.570 ± 0.020; B₆, 25 418.917 ± 0.047; A_ζ6ηJ, ?0.562 ± 0.030; |q₆|, 8.70 ± 0.13 MHz. Errors are 2.5 times the standard deviations.     

Doppler-limited dye laser excitation spectroscopy of the HSO radical

The cw dye laser excitation spectrum of the vibronic transition of the HSO radical was observed between 16 420 and 16 520 cm⁻¹ with Doppler-limited resolution, 0.03 cm⁻¹. The HSO radical was produced by reaction of discharged oxygen with H₂S or CH₃SH. The observed spectra were assigned to 751 transitions of the K′_a ← K″_a = 2 ← 3, 1 ← 2, 0 ← 1, 1 ← 0, 2 ← 1, and 3 ← 2 subbands, and were analyzed to determine rotational constants, centrifugal distortion constants, and spin-rotation interaction constants with good precision. The signs of the spin-rotation interaction constants were determined for both the upper and the lower state from the observed spectra. The band origin obtained is 16 483.0252 (2.5σ = 0.0013) cm⁻¹. The molecular constants which were determined reproduce the observed transitions with an average deviation of 0.0045 cm⁻¹.     

Microwave spectroscopic study of the SiF radical

The microwave spectrum of the SiF radical was observed in both ${}^2\text{Π}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ and ${}^2\text{Π}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$ of the ground vibronic state. The SiF radical was produced by a dc discharge either in a $\text{SiF}{}_4\text{SiH}{}_4$ mixture or in a transient molecule SiF₂ generated by the reaction of SiF₄ with heated solid silicon. The latter gave twice as intense a spectrum. A least-squares fit to the observed spectrum showed the rotational constant and the centrifugal distortion constant to be 17 350.2752(63) and 0.03188(13) MHz, respectively, with three standard errors in parentheses applying to the last digits of the constants. The lambda-doubling parameter p₀ was found to be negative, ?87.67 MHz, indicating that the ²Σ⁺ excited state contributions dominate over those of ²Σ^?. All four hyperfine coupling constants a, b, c, and d were determined and were employed to discuss the unpaired-electron spin and orbital distributions in the SiF radical.