Wei Hua's Four Parameter Potential Comments and Computation of Moleculer Constants \alpha_e and \omega_e x_e

The value of adjustable parameter $C$ and the four-parameter potential $U(r) = D_{e}\left [ \frac{1-{exp}[-b(r-r_{e})]}{1-C{exp} [-b(r-r_{e})]} \right ]^{2}$ has been expressed in terms of molecular parameters and its significance has been brought out. The potential so constructed, with $C$ derived from the molecular parameters, has been applied to ten electronic states in addition to the states studied by Wei Hua. Average mean deviation has been found to be 3.47 as compared to 6.93, 6.95 and 9.72 obtained from Levine2, Varshni and Morse potentials, respectively. Also Dunham's method has been used to express rotation-vibration interaction constant $(\alpha_{e})$ and anharmonocity constant $(\omega_{e}x_{e})$ in terms of $C$ and other molecular constants. These relations have been employed to determine these quantities for 37 electronic states. For $\alpha_{e}$, the average mean deviation is 7.2% compared to 19.7% for Lippincott's potential which is known to be the best to predict the values. Average mean deviation for $(\omega_{e}x_{e})$ turns out to be 17.4% which is almost the same as found from Lippincott's potential function.Comment: 19 RevTex Pages, 1 Ps figure, submitted to J. Phys.

Electronic transitions of cobalt carbide, CoC, near 750 nm: a good example of case (b(betaS)) hyperfine coupling

The laser induced fluorescence spectrum of jet-cooled CoC near 750 nm has been measured at high resolution following the reaction of laser-ablated cobalt atoms with methane. The X2Σ+ ground state of CoC is an unusually good example of Hund's case (bβS) coupling. Since Co has a nuclear spin I=7/2, each rotational level is split by the Fermi contact interaction into G=3 and G=4 components, where G=I+S; the splitting for N=0 is more than 0.5 cm-1. The X2Σ+ state begins to uncouple toward case (bβJ) with increasing rotation. Transitions to various 2Π excited states occur in the region 13 000-14 500 cm-1; the most prominent of these (for which high resolution spectra have been recorded) lie at 13 079 cm-1 ( 2Π3/2) and 13 343 cm-1 (2Π 1/2). The (bβS) coupling in the ground state produces some unexpected hyperfine intensity patterns, which have been studied in detail. A very low-lying 2Δi state, whose Ω=5/2 and Ω=3/2 components lie at 221 and 1173 cm-1, has been identified. Laser excitation of the 2Π3/2- 2Δ5/2 transition has been observed by monitoring the strong 2Π3/2-X2Σ+ emission, which has allowed the 2Δ5/2 state to be characterized at high resolution. A total of 879 rotational-hyperfine transitions between the various 2Π1/2, 2Π3/2, 2Δ5/2, and 2Σ+ states have been assigned and fitted. Matrix elements for a 2Σ+ state in case (b βS) coupling are listed. © 1995 American Institute of Physics.M. Barnes, A. J. Merer and G. F. Meth

Avaliação de diferentes tubos de acesso para medição da umidade do solo através do uso de sonda de nêutrons.

bitstream/CNPAB-2010/27253/1/doc059.pd

Effect of the first wave of COVID-19 on Poison Control Centre activities in 21 European countries : an EAPCCT initiative

Peer reviewe

HIGH RESOLUTION FOURIER TRANSFORM SPECTROSCOPY OF THE SINGLET MOLECULAR OXYGEN-IODINE REACTION AND POPULATIONS OF THE BOu+B O^{+}_{u} AND A Iu STATES THROUGH NON LINEAR INVERSION OF EMISSION SPECTRA

Author Institution: Laboratoire de Specdrometrie lonique et Moleculairs; Laboratokire Aime Cotton, CNRS IIThe dissociation of molecular lodine $I_{2}$ by metastable oxygen $O_{2} (^{1}\Delta_{g})$ is poorly understood. It leads to the dissociation of $I_{2}$. Knowledge of this process is important to assessing the ultimate efficiencies of high-power Chemical Oxygen lodine Lasers. In our analysis $O_{2}(^{1}\Delta_{g})$ is obtained from a microwave discharge in oxygen. The flow of less than 10\% of $O_{2}(^{1}\Delta_{g})$ is mixed with pure lodine. The reaction gives a flame emitting from $3 700 cm^{-1}$ to $20000 cm^{-1}$. We observe this flame along the axis with a high resolution Fourier Transform spectrometer. The $10000 - 20000 cm^{-1}$ emission is due to the $BO^{+}_{u} -xO^{+}_{2}$ transition and allows to determine the populations of the $BO^{+}_{u}$ It rovibrational levels.The red region come from $A lu \rightarrow. X O^{+}_{9}$ from which we obtain the A 1u populations We have set a general program that gives from non linear least squares fits the rovibrational populations and their statistical errors A 1u serves as a reservoir with a non Boltzmann vibrational distrbition and B O has a maximum population around $v=30-35$ The rotational distribution in $A 1u or B O^{+}_{u}$ is boltzmann and corresponds to $370 \pm 20 K$. We will give our main results. Our general fitting method will be presented and statistical or systematic errors discussed

THE ELECTRONIC SPECTRA OF HYDRIDES OF GROUP IIIA METALS

Author Institution: Laboratoire de Spectrom\'{e}trie Ionique et Mol\'{e}culaireUsing a composite wall hollow cathode lamp we were able to excite easily the electronic spectra of group IIIa metal hydrides. Three new electronic band systems of LaH and LaD appearing between 5300 and 6500 {\AA} have been studied. The rotational structure, the intensity distribution in the P, Q, and R branches, and the A-doubling show that these bands may be ascribed to ($^{3}\Phi$ $\rightarrow^{3}\Delta$), ($^{1}\Delta$, $^{1}\Sigma \rightarrow ^{1}\Pi$) transitions. The rotational study of YD and YH has been undertaken