An analysis of the four nuclear quadrupole problem: The microwave spectrum of cyanogen azide

We have derived expressions for the Hamiltonian matrix elements for the coupling of any number of quadrupolar nuclei with the molecular rotation using the Wigner n-j formalism. These expressions have been used to analyse the nuclear quadrupole hyperfine structure of the rotational spectrum of cyanogen azide, NCN₃. The analysis was effected by comparing the experimental high resolution spectral traces with computer simulated traces from which the nuclear quadrupole coupling constants obtained are (MHz)

$\text{x}{}_{\mathrm{aa}}\text{(1) = 4.82 ± 0.02,}\text{x}{}_{\mathrm{bb}}\text{(1) = ?0.70±0.08,}$

$\text{x}{}_{\mathrm{aa}}\text{(2) = ?0.85 ± 0.07,}\text{x}{}_{\mathrm{bb}}\text{(2) = 0.70±0.08,}$

$\text{x}{}_{\mathrm{aa}}\text{(3) = ?0.75 ± 0.07,}\text{x}{}_{\mathrm{bb}}\text{(3) = 0.70±0.05,}$

$\text{x}{}_{\mathrm{aa}}\text{(4) = ?2.27 ± 0.04,}\text{x}{}_{\mathrm{bb}}\text{(4) = 0.70±0.07,}$

Small corrections to the previously reported rotational constants are given.     

The centrifugal distortion constants of disulfur monoxide

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):

$\text{A = 41915.44,}\text{B = 5059.07,}\text{C = 4507.19}$

$\text{δ}{}_{\mathrm{J}}\text{= 1.895 X 10}{}^{\mathrm{?}}\text{, δ}{}_{\mathrm{JK}}\text{= ?3.192 X 10}{}^{\mathrm{?2}}\text{,}\text{δ}{}_{\mathrm{K}}\text{= 1.197 X 10}{}^0$

$\text{δ}{}_{\mathrm{J}}\text{= 3.453 X 10}{}^{\mathrm{?4}}\text{and δ}{}_{\mathrm{K}}\text{= 1.223 X 10}{}^{\mathrm{?2}}$

The centrifugal distortion constants obtained from the rotational spectrum are used to discuss the vibrational spectrum of disulfur monoxide.     

Environmental gamma radiation measurements in Bangladeshi houses

Indoor gamma dose rate in air measured using TLDs in the Dhaka district is not wide ranging and follows a normal distribution with an arithmetic mean of $\text{1.54±0.26}\text{mGy}\text{y}{}^{\mathrm{-1}}$. The result has been compared with those found by other investigators for different locations of the world. Measurements were made on a monthly basis for a year period, and a sinusoidal variation of monthly indoor gamma radiation of the type: $\text{d=160+65}\text{cos}\text{π/6}\text{(m−1)}$, where d is the indoor dose rate $\text{(}\text{nGy}\text{h}{}^{\mathrm{-1}}\text{)}$ and m the month. This might be due to the seasonally varied air exchange rates of the houses. The average annual effective dose and the collective dose equivalent for the residents were estimated to be $\text{0.86}\text{mSv}$ and $\text{172.20}\text{man}$-Sv, respectively, based on the indoor gamma exposure.     

Ambiguities on structure analysis of Fe–N thin films

Fe–N thin films with good soft magnetic properties were prepared by RF sputtering and vacuum annealed at 250°C under 12000 A/m magnetic field for 4 h. The structure of α′ in thin films deposited at room temperature is different from α′ formed through the Bain mechanism in bulk samples. In thin films, the lattice parameters of α′ are $\text{c=2.866+1.559}\text{C}{}_{\mathrm{<mtext>N</mtext>}}{}^{\mathrm{<mtext>\alpha </mtext><mtext>\prime </mtext>}}\text{,a=2.864+0.181}\text{C}{}_{\mathrm{<mtext>N</mtext>}}{}^{\mathrm{<mtext>\alpha </mtext><mtext>\prime </mtext>}}$.     

Emission and excitation spectra of feldspar inclusions within quartz

Emission spectra obtained for three irradiated granular quartz samples under $\text{1.43}\text{eV}$ excitation exhibited the 2.2 and $\text{3.1}\text{eV}$ emission bands characteristic of feldspars. Excitation spectra of these same samples and several others show the $\text{1.44}\text{eV}$ resonance typical of feldspars. This provides convincing evidence that the 2.2 and $\text{3.1}\text{eV}$ infrared stimulated luminescence observed in these granular quartz samples arises from feldspar inclusions.     

A time-resolved luminescence spectroscopy study of self-trapped excitons in KH2PO4 crystals

A complex investigation of the dynamics of electronic excitations in potassium dihydrophosphate (KDP) crystals is performed by the low-temperature time-resolved vacuum ultraviolet optical luminescence spectroscopy with subnanosecond time resolution and with selective photoexcitation by synchrotron radiation. For KDP crystals, data on the kinetics of the photoluminescence (PL) decay, time-resolved PL spectra (2–$\text{6.2}\text{eV}$), and time-resolved excitation PL spectra (4–$\text{24}\text{eV}$) at $\text{10}\text{K}$ were obtained for the first time. The intrinsic character of the PL of KDP in the vicinity of $\text{5.2}\text{eV}$, which is caused by the radiative annihilation of self-trapped excitons (STEs), is ascertained; σ and π bands in the luminescence spectra of the STEs, which are due to singlet and triplet radiative transitions, are resolved; and the shift of the σ band with respect to the π band in the spectra of the STEs is explained.