States Of N2 Research Articles

Modeling the spectrum of the 2ν2 and ν4 states of ammonia to experimental accuracy.

The vibrational spectrum of ammonia has received an enormous amount of attention due to its potential prevalence in hot exo-planet atmospheres and persistent challenges in assigning and modeling highly excited and often highly perturbed states. Effective Hamiltonian models face challenges due to strong coupling between the large amplitude inversion and the other small amplitude vibrations. To date, only the ground and ν2 positions could be modeled to experimental accuracy using effective Hamiltonians. Several previous attempts to analyze the 2ν2 and ν4 energy levels failed to model both the microwave and infrared transitions to experimental accuracy. In this work, we performed extensive experimental measurements and data analysis for the 2ν2 and ν4 inversion-rotation and vibrational transitions. We measured 159 new transition frequencies with microwave precision and assigned 1680 new ones from existing Fourier transform spectra recorded in Synchrotron SOLEIL. The newly assigned data significantly expand the range of assigned quantum numbers; combined with all the previously published high-resolution data, the 2ν2 and ν4 states are reproduced to experimental accuracy using a global model described here. Achieving experimental accuracy required inclusion of a number of terms in the effective Hamiltonian that were neglected in previous work. These terms have also been neglected in the analysis of states higher than 2ν2 and ν4 suggesting that the inversion-rotation-vibration spectrum of ammonia may be far more tractable to effective Hamiltonians than previously believed.

Transition from direct to sequential two-proton decay in s–d shell nuclei

Transitions among different mechanisms of two-proton decay are studied in general. The introduced improved direct-decay model generalizes the semi-analytical models used before and provides flawless phenomenological description of three-body correlations in $2p$ decays. This is demonstrated by examples of the low-lying $^{16}$Ne state decays. Different forms of transition dynamic are shown to be highly probable beyond the proton dripline for the $s$-$d$ shell nuclei. It is demonstrated that transition dynamic of $2p$ emitters can provide means for extraction of a width of the ground-state resonance of a core+$p$ subsystem of the core+$2p$ system. Practical applicability of the method is demonstrated by properties of the $^{14}$F ground state derived from the $^{15}\mbox{Ne}\rightarrow ^{\,13\!\!}\mbox{O}+2p$ decay data and of the $^{29}$Cl ground state derived from the $^{30}\mbox{Ar}\rightarrow ^{\,28\!\!}\mbox{S}+2p$ decay data.

Stereoselectivity in Autoionization Reactions of Hydrogenated Molecules by Metastable Noble Gas Atoms: The Role of Electronic Couplings.

Focus in the present paper is on the analysis of total and partial ionization cross sections, measured in absolute value as a function of the collision energy, representative of the probability of ionic product formation in selected electronic states in Ne*-H2 O, H2 S, and NH3 collisions. In order to characterize the imaginary part of the optical potential, related to electronic couplings, we generalize a methodology to obtain direct information on the opacity function of these reactions. Such a methodology has been recently exploited to test the real part of the optical potential (S. Falcinelli et al., Chem. Eur. J., 2016, 22, 764-771). Depending on the balance of noncovalent contributions, the real part controls the approach of neutral reactants, the removal of ionic products, and the structure of the transition state. Strength, range, and stereoselectivity of electronic couplings, triggering these and many other reactions, are directly obtained from the present investigation.

Dot-ring nanostructure: Rigorous analysis of many-electron effects.

We discuss the quantum dot-ring nanostructure (DRN) as canonical example of a nanosystem, for which the interelectronic interactions can be evaluated exactly. The system has been selected due to its tunability, i.e., its electron wave functions can be modified much easier than in, e.g., quantum dots. We determine many-particle states for Ne = 2 and 3 electrons and calculate the 3- and 4-state interaction parameters, and discuss their importance. For that purpose, we combine the first- and second-quantization schemes and hence are able to single out the component single-particle contributions to the resultant many-particle state. The method provides both the ground- and the first-excited-state energies, as the exact diagonalization of the many-particle Hamiltonian is carried out. DRN provides one of the few examples for which one can determine theoretically all interaction microscopic parameters to a high accuracy. Thus the evolution of the single-particle vs. many-particle contributions to each state and its energy can be determined and tested with the increasing system size. In this manner, we contribute to the wave-function engineering with the interactions included for those few-electron systems.

Probing electron correlation through radiative lifetime measurements upon inner-valence photoionization of Ne and Ar

This work demonstrates that electron correlation can have a strong effect on the radiative lifetime of atoms. We report measurements of the radiative lifetimes of inner-valence hole states, the 3s3p6 2S1/2 state of Ar+ and the 2s2p6 2S1/2 state of Ne+ by using the time-correlated single photon counting technique combined with photoionization by synchrotron radiation. Theoretical calculations utilizing the multi-configuration Dirac–Fock method agreed well with the experimental results. In particular, the radiative lifetime was found to depend very sensitively on the mixing of valence excited state configurations. While the Ne+ 2s2p6 2S1/2 state only has relatively weak inter-shell correlation, Ar+ 3s3p6 2S1/2 state has strong intra-shell correlation within the M-shell. This intra-shell correlation enhances configuration mixing and causes the radiative lifetime of the Ar+ 3s3p6 2S1/2 state to become very much longer than that of the Ne+ 2s2p6 2S1/2 state.

Towards data oriented analysis of the art market: survey and outlook

Due to the constantly growing interest in alternati ve investments, the art market has become the subject of numerous studies. By publishing sales data, many services and aucti on houses provide a foundati on for further research on the latest trends. Determining the defi niti on of the arti sti c value or formalisati on of appraisal may be considered quite complex. Stati sti cal analysis, econometric methods or data mining techniques could pave the way towards bett er understanding of the mechanisms occurring on the art market. The goal of this paper is to identi fy, describe and compare soluti ons (and related challenges) that help to analyse, make decisions and defi ne state of the art in the context of the intersecti on of econometrics on art markets and computer science. This work is also a starti ng point for further research.

Hill horticulture-status, problems and strategies

The hilly areas constitute undulated terrains with a variety of agro-climatic conditions, low population density, very low per capita availability of land and practical difficulties in intensive cropping. For economic upliftment of the rural hilly community and environmental restoration, proper land use planning has to be done with different horticultural and plantation crops. Cultivation in these regions is carried out in fragmented and terrace fields. The farming system i.e. agriculture as well as horticulture is mainly dependent on composition of the soil, position of the field, slope aspects, presence/absence of irrigation, density of the population and their literacy rates etc. In order to boost up the horticulture sector central and state governments are working through introduction of Horticulture Mission for North East and Himalayan (HMNEH) States is a part of Mission for Integrated Development of Horticulture (MIDH) scheme, being implemented for overall development of Horticulture in NE and Himalayan states. A complete package of supply coupled with marketing and processing facilities should be made available at subsidized prices to the farmers in the hilly areas. Crop diversification should be targeted with special emphasis on high value crops such as vegetables, vegetable seeds, orchids, spices and mushrooms with adequate marketing facilities.

Global performance of multireference density functional theory for low-lying states insd-shell nuclei

We present a comprehensive study of low-lying states in even-even Ne, Mg, Si, S, Ar isotopes with the multireference density functional theory (MR-DFT) based on a relativistic point-coupling energy density functional (EDF). Beyond mean-field (BMF) effects are taken into account by configuration mixing of both particle-number and angular-momentum projected axially deformed states with generator coordinate method (GCM). Global performance of the MR-DFT for the properties of both ground state and of the first $2^+, 4^+$ states is examined, in comparison with previous studies based on nonrelativistic EDFs and available data. Our results indicate that an EDF parameterized at the BMF level is demanded to achieve a quantitative description.

Multiple Auger decay of the neon1s-core-hole state studied by multielectron coincidence spectroscopy

The Auger decay processes from the $1s$-core-hole state of Ne have been investigated with a multielectron coincidence method. We have observed the double and triple Auger decays, in which both cascade and direct processes are identified from different ways in energy sharing between the Auger electrons. Branching ratios for the different electronic configurations of the Auger final states are determined from the corresponding electron coincidence yields. Particularly for the double Auger decay, the branching ratios are divided into the individual contributions from direct and cascade paths.

Properties of a weakly ionized NO gas sensor based on multi-walled carbon nanotubes

Nitric oxide NO is one of the major targets for environmental monitoring, but the existing NO sensors are limited by their low sensitivity and narrow test range. Here, a NO gas sensor employing multiwalled carbon nanotubes (MWCNTs) was fabricated, and its properties in NO–N2 mixture were investigated from both emission and ionization. The current Ie passing through the nanotubes cathode was found to decrease with increasing NO concentration and increase linearly in different slopes with the extracting voltage Ue. It is shown that the Schottky barrier of the MWCNTs calculated by Ie increased with NO concentration due to the adsorption of NO gas, which restrained the electron emission and consequently weakened the ionization. The positive ion currents Ic passing through the collecting electrode at different voltages of Ue were found to monotonically decrease with increasing NO concentration, which was induced by both of the reduced electron emission and the consumption of the two excited metastable states N2(A3∑u+) and N2(a′1∑u−) by NO. The sensor exhibited high sensitivity at the low temperature of 30 °C. The calculated conductivity was found to be able to take place of Ic for NO detection in a wide voltage range of 80–150 V Ue.

Millimeter-wave spectroscopy of the FeCO radical in the ν2 and ν3 vibrationally excited states.

The pure rotational spectra of the FeCO radical in the ν2 (bending) and ν3 (Fe-C stretching) vibrational states of the ground X̃(3)Σ(-) electronic state were observed in the millimeter-wave region. The equilibrium rotational and centrifugal distortion constants were determined to be Be = 4374.631 (58) MHz and De = 1.1666 (20) kHz together with the spin-spin coupling constant λe = 691.89 (37) GHz and spin-rotation coupling constant γe = - 1079.4 (55) MHz with use of the millimeter-wave results and the ν1 IR data. The equilibrium bond length for Fe-C was derived to be 1.725 Å assuming that for C-O to be 1.159 Å. Since the vibronic symmetry of the excited state of bending vibration is (3)Π, the analysis of spectrum in the ν2 state required an effective spin-orbit interaction constant of A2 = 6.0219 (61) GHz together with three parity doubling constants of o2 = 36.168 (10) GHz, p2 = 85.18 (34) MHz, and q2 = 4.7024 (17) MHz. The effective spin-orbit interaction constant A2 is attributed to the vibronic mixing of the (3)Π excited electronic states. The vibronic mixing also cause the parity doubling constants o2 and p2, but the main contribution to q2 is given by the vibrational l-type doubling.

Population of 2p 54p levels of Ne in the afterglow of discharge in helium with small admixtrue of neon

The processes of population of 3p1, 3p3, 3p6, and 3p9 levels (in Paschen’s notation) of neon atom has been studied by spectroscopic methods during the decay period of plasma produced in helium containing small concentrations of neon ([Ne]/[He] ≈ 10–5). Based on the comparative analysis of temporal variation of the intensities of NeI spectral lines of 2p54p → 2p53s and 2p54d → 2p53p transitions, it is established that the formation of exited Ne(2p54p) atoms in the afterglow is related to the dissociative recombination (DR) of homo- and heteronuclear ions and electrons via reactions HeNe+ + e → Ne(2p54p) + Ne and Ne2+ e → Ne(2p54p) + Ne. The relative contributions of these processes to the rate of population of various Ne(3pj) states depend on the energies of 3pj levels. The upper 3p1 level lying above the ground state of Ne2+(v = 0) ion is populated almost entirely due to the DR of HeNe+ heteronuclear ions. The DR of Ne2+ ions and electrons significantly contributes to \(\Gamma _{3p_j }^{Ne_2^ + }\) flux in population of low-lying 3p3, 3p6, and 3p9 levels; \(\Gamma _{3p_j }^{Ne_2^ + }\) value increases with decreasing energy of 3pj level.

A Simplified Method for Identification of the Vibrational Series of Long-Range States in Na2

We performed two-color photoassociative ionization experiments in cold sodium atoms in a dark MOT. We produce a sample where most of the atoms were in the ground hyperfine state F=1. Applying a laser with variable frequency, in the region of 0 to −32 GHz, we obtained a photoassociative spectra containing sequences of different long-range potentials. Using the scaling law for intermediate states, we identified the vibrational series of involved states, separating the sequences. In this way, we have identified the vibrational series for the $1_{g}, 0_{u}^{+}$ , and $0_{g}^{-}$ states contributions.

Food Security in North-East Region of India — A State-wise Analysis

With the adoption of high-yielding varieties of paddy, the foodgrains production has increased in North-East region of India. To estimate the growth performance of agriculture, time series data on area, production and productivity of foodgrains have been analysed for the period 1972–73 to 2011–12, which was divided into three decades, viz. 1982–83 to 1991–92 (I decade), 1992–93 to 2001–02 (II decade), 2002–03 to 2011–12 (III decade) and overall period 1972–73 to 2011–12. During the overall period, among the states, Nagaland registered the highest significant growth in area, production and yield, followed by Arunachal Pradesh and Mizoram. All the NE states have shown positive growth rates in area, production and yield increase. The decomposition analysis of growth has suggested that sources of output growth were almost same in all the periods. During the first decade, the major contribution in the change of foodgrain production in the region was of area effect (74.8%), followed by yield effect (22.8%), whereas in all-India, the yield effect was 71 per cent. During the second period, the region had almost half sharer (50.3%) of area effect in food security, followed by yield effect (42.7%). In the third decade, yield effect was the major contributing factor to food security of the region (98.6%), except of Nagaland and Sikkim where major contribution has been found of area effect.

Alpha condensates and nonlocalized cluster structures

We discuss a container structure for non-gaslike cluster states, in which single Tohsaki-Horiuchi-Schuck-ROpke (THSR) wave functions are shown to be almost 100% equivalent to the full solutions of the corresponding RGM/GCM equations, for the inversion doublet band states in 20Ne, α-linear-chain states, and α + α + A cluster states in 9ΛBe. The recognition of the fact that the THSR wave function describes well not only gaslike cluster states but also non-gaslike cluster states is a recent remarkable development of nuclear cluster physics. This fact tells us that the cluster structure is composed of cluster-mean-field motion under the constraint of inter-cluster Pauli repulsion, in which we call the cluster-mean-field potential the container. We demonstrate that the evolution of the cluster structure of a nucleus is governed by the size parameter of the cluster-mean-field potential (container), for 16O nucleus.

Effects of Direct Double Auger Decay on the Population Dynamics of Neon Irradiated by Ultraintense x‐ray Pulses

AbstractThe population and charge state distribution of neon interacting with ultraintense x‐ray pulses are investigated by solving a time‐dependent rate equation in the detailed level‐accounting (DLA) approximation. Due to the detailed description of neon atom and ions, our DLA result improves the agreement between predictions and experimental measurements for odd neon charge states. In the framework of the DLA formalism, we further studied the effects of direct double Auger decay (DDAD) on charge state distribution. After the 1s photoionization of neon atom, the DDAD processes give accessible decay channels from the K‐shell hole state of Ne+ to levels of Ne3+, resulting in an increase of the population fraction of Ne3+ and a decrease of that of Ne2+. Compared with the results without considering the DDAD effects, better agreement is obtained between theory and experiment. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Observation of long-range three-body coulomb effects in the decay of (16)Ne.

The interaction of an E/A=57.6-MeV ^{17}Ne beam with a Be target is used to populate levels in ^{16}Ne following neutron knockout reactions. The decay of ^{16}Ne states into the three-body ^{14}O+p+p continuum is observed in the High Resolution Array (HiRA). For the first time for a 2p emitter, correlations between the momenta of the three decay products are measured with sufficient resolution and statistics to allow for an unambiguous demonstration of their dependence on the long-range nature of the Coulomb interaction. Contrary to previous measurements, our measured limit Γ<80 keV for the intrinsic decay width of the ground state is not in contradiction to the small values (of the order of keV) predicted theoretically.

Dipole moments of CH3F in the ν3 and ν6 vibrational excited states from the Stark effect

Both the parallel and perpendicular rotational Stark components of the methyl fluoride J, k, l: 2, ±1, 0←1, ±1, 0 and 2, ±1, ∓1←1, ±1, ∓1 lines in the ν3 and ν6 excited vibrational states were measured in the microwave region of ca 100GHz at the Stark fields in the range of ca 150–1100V/cm. The analysis of the Stark components was complicated by unexpected hyperfine structure patterns spanning a few MHz, which were observed for MJ components with large Stark shifts (>300MHz), most probably due to an enhancement through the Stark effect. The permanent electric dipole moments for these two vibrational states were derived from selected separated hyperfine components of the Stark components: μ3=1.90345(46)D, μ6=1.86394(32)D (the expanded uncertainties are given with the coverage factor k=2). The significant perturbational second-order Stark contributions were simply eliminated using a Stark component difference approach. Third-order Stark contributions were included in the analysis, and higher-order Stark contributions and polarizability contributions were neglected since they are inconsequential in this study.

Vibrational relaxation of O3(ν2) by O((3)P).

Laboratory measurements of the rate coefficient for quenching of O3(ν2) by ground-state atomic oxygen, kO(ν2), at room temperature are presented. kO(ν2) is currently not well known and is necessary for appropriate nonlocal thermodynamic equilibrium modeling of the upper mesosphere and lower thermosphere. In this work, a 266 nm laser pulse photolyzes a small amount of O3 in a slow-flowing gas mixture of O3, Xe, and Ar. This process simultaneously produces atomic oxygen and increases the temperature of the gas mixture slightly, thereby increasing the population in the O3(ν2) state. Transient diode laser absorption spectroscopy is used to monitor the populations of the O3(ν2) and ground vibrational states as the system re-equilibrates. Relaxation rates are measured over a range of quencher concentrations to extract the rate coefficient of interest. The value of kO(ν2) was determined to be (2.2 ± 0.5) × 10(-12) cm(3) s(-1).

Three-body model calculations for N = Z odd-odd nuclei with T = 0 and T = 1 pairing correlations

We study the interplay between the isoscalar (T=0) and isovector (T=1) pairing correlations in N=Z odd-odd nuclei from 14N to 58Cu by using three-body model calculations. The strong spin-triplet T=0 pairing correlation dominates in the ground state of 14N, 18F, 30P, and 58Cu with the spin-parity J^{\pi}=1+, which can be well reproduced by the present calculations. The magnetic dipole and Gamow-Teller transitions are found to be strong in 18F and 42Sc as a manifestation of SU(4) symmetry in the spin-isospin space. We also discuss the spin-quadrupole transitions in these nuclei.