Low Structure Research Articles

Structure and electronic excitation spectra of low-lying isomers of Aun clusters (n = 2–20). A DFT study

The global structure optimization using the DFT-calibrated empirical potentials followed by the geometry optimization at the DFT level (BPW91/LANL2DZ) has been carried out in order to locate the low-lying isomers of Aun clusters (n = 2–20) modeling the sub-nanoparticles of the photocatalytic composite materials. The total energies, thermodynamic parameters and electronic properties of the located global and low-lying structures of various multiplicities are estimated, and their dependence on the nuclearity and cluster morphology are discussed. For the low-lying isomers, the electronic excitations spectra were calculated at the CAM-B3LYP/LANL2DZ level, and the electronic density redistribution during the excitations were analyzed. This analysis demonstrates that the planar clusters have the highest absorption ability and, at the same time, are the favorable structures for the intermolecular charge redistribution.

Measurement of Personality Structure by the OPD Structure Questionnaire Can Help to Discriminate Between Subtypes of Eating-Disorders.

BackgroundDifferentiation between purging type (AN-P) and restricting type (AN-R) is common in anorexia nervosa (AN) and relevant for clinical practice. However, differences of personality pathology in eating disorders (ED) and their subtypes, which can be captured by the operationalized psychodynamic diagnosis (OPD) system, have not been systematically investigated to date.ObjectivesThe aim of this study was to explore differences in personality structure between the subtypes of AN and bulimia nervosa (BN) using the OPD structure questionnaire (OPD-SQ). In addition, the ability of the instrument to support the classification of eating disorders was examined.Materials and MethodsWe conducted a retrospective, exploratory study in a subset sample of a larger validation study. The OPD-SQ had been collected from n = 60 patients with AN or BN. Patients were assigned to the ED groups by clinical assessment. Statistical analyses included multivariate analysis of variance (MANOVA) and discriminant analysis.ResultsDifferences between ED groups were observed on 5 OPD-SQ main scales and 9 subscales, as well as on the global scale. AN-P patients demonstrated the lowest personality structure on most of the main scales and subscales, whereas AN-R patients showed a higher personality structure level as compared to both BN and AN-P patients. The OPD-SQ scales with the largest differences include self-perception, object perception, and attachment to internal objects. Discriminant analysis resulted in satisfactory assignment to ED groups by OPD-SQ subscales.ConclusionsPersonality structure was found to be less developed in patients with BN and AN-P as compared to patients with AN-R. Although the results have to be proven in larger prospective studies, these results suggest that the OPD-SQ may be used to support the clinical assessment and classification in patients with EDs.

Hydration of acetic acid-dimethylamine complex and its atmospheric implications

Atmospheric aerosols are closely related to weather, climate and human health, and New particle formation (NPF) is a major source of atmospheric aerosols. Currently, some field observations and experiments indicate that acetic acid (HOAc) could be involved in NPF events. However, mechanism of acetic acid nucleation is still unclear. In this study, the low-lying structures and thermodynamics of acetic acid (HOAc)-dimethylamine (DMA)-water (W) system were studied at PW91PW91/6–311++G (3df, 3pd) level. We found that acetic acid forms relatively stable clusters with dimethylamine, and that proton transfer enhances the strength of the hydrogen bond in (HOAc) (DMA) (H2O)n (n = 2–4) clusters. Temperature has an important effect on the distribution of isomers, especially for (HOAc) (DMA) (H2O)2 clusters. Besides, all the isomers contribute to the nucleation of clusters. The various RH has a negligible effect on the hydrate distribution. However, the non-hydrated clusters are always dominant and they are easy to form stable cluster, as seen from the comparison of hydrate distributions and cluster formation rates. The above analyses indicate that (HOAc) (DMA) is relatively stable and some larger clusters based on (HOAc) (DMA) may participate in new particle formation.

Low-lying states of 92,93Nb excited in the reactions induced by the weakly-bound nucleus 6Li near the Coulomb barrier * * Supported by National Natural Science Foundation of China (U1867210, 11775098, 11475013, U1832130 and 11775316)

Excited states of odd-odd nucleus 92Nb and odd-A nucleus 93Nb were populated in the 6Li+ 89Y reaction with an incident energy of 34 MeV. The processes that produce 92,93Nb and can be measured by a combination of light charged particle and gamma ray measurements are discussed. Twenty new transitions are observed and eight new levels are constructed in 92Nb, and in addition two new transitions are added to the level scheme of 93Nb. Using shell model calculations, the low-lying structure of 92Nb is investigated and compared with the experimental results.

Thermochemistry of Intermediates and Products in the Oxidation Reaction of 1,1,2-Trifluoroethene via OH Radical.

Density functional theory (DFT) and composite ab initio based calculations are performed on trifluoroethane along with intermediate radicals, parent molecules of the radicals, and products related to the reaction of hydroxyl radical with 1,1,2-trifluoroethene, as a reference for hydrofluoroolefins (HFO). Potential energy barriers for internal rotations have been computed. Calculated torsional potentials are incorporated into the determination of entropy, S°298, and heat capacities as a function of temperature, Cp(T), for each target molecule. Six isodesmic or isogyric reactions and five calculation methods are used to determine heats of formation at 298 K (ΔfH298) in kcal mol-1 of each target species. The CBS-APNO method shows the best agreement with experimental data in comparisons from 16 reference reactions on ΔrxnH of each method. The lowest configuration structures of each target species are reported. Intramolecular hydrogen bonds between the hydroxyl hydrogen atom and the fluorine atom on the adjacent carbon can stabilize molecules by up to 3 kcal mol-1. R-OH bond dissociation energies are observed to increase with the number of fluorine atoms on the carbon connected to hydroxy group. Recommended ΔfH298 values in kcal mol-1 derived from the most stable conformers are CF2(OH)CH2F (-213.0), CF2(O•)CH2F (-148.6), CF2(OH)C•FH (-162.4), CHF2CHFOH (-207.5), CHF2C•FOH (-158.3), C•F2CHFOH (-155.5), CHF2CHFO• (-150.4), CF3CH2OH (-212.5), and CF3C•HOH (-167.9).

Theoretical investigations on stable structures of C60-nNn (n=2–12): Symmetry, model interaction, and global optimization

Combining the extended cluster expansion method and the first-principles calculations, we have systematically investigated the structural stabilities of nitrogen doped C60 fullerene. With the structural recognition, we have calculated all possible isomers of C60-nNn (n = 1–4) to obtain their ground state structures using the first-principles method. For C60-nNn (n = 5–9) heterofullerenes, we have estimated the energy by the extended cluster expansion method to screen the candidates efficiently, followed by first-principles confirmation for the low-lying structures. For C60-nNn with more than 9 nitrogen atoms, we developed a classification method to select the candidates and successfully obtained the low-lying isomers. The most stable structures for C60-nNn (n = 3–11) we obtained have lower energies compared to the structures in previous studies. Notably, we have found 26 low-lying structures of C48N12 azafullerenes, from their 11.6 billion isomers.

Spin and parity determination of the 3.004-MeV level in Al27 : Its low-lying multiplet structure

Spin and parity determination of the 3.004-MeV level in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Al</mml:mi><mml:mprescripts /><mml:none /><mml:mn>27</mml:mn></mml:mmultiscripts></mml:math> : Its low-lying multiplet structure

English

In this study, multistage sampling technique was used. 132 households were selected out of 2,943 households in three sampled kebeles (the lowest administrative structure in Ethiopia) of Godere Woreda (Woreda is administrative structure above Kebele). Household-based interview, key informants interview (KII) and transect walk were used in order to collect data. Practiced households have harvested an average of 44.74 quintal of crop production per hectare per year while non-practiced households reaped a mean of 23.29 quintal of crop production per hectare per year with mean difference equivalent to 21.5 kg while practiced households earned an average of 3282.58 and non-practiced households earned a mean of 2661.97 Ethiopian birr per household per year with mean difference equivalent to 620.6. Practiced households demand an average of four persons while non-practiced households require an average of two persons per household. Practiced households use a mean of 30.89 kg of Di-amonnium phosphate (DAP) while non-practiced households use an average of 62.92 kg in their crop fields with mean difference equivalent to 32.03 kg. Practiced households use a mean of 22.27 kg of Urea fertilizer per household in their crop fields whereas non-practiced households use an average of 53.56 kg with mean difference equivalent to 31.28 kg of Urea fertilizer per household. With these findings, it is rationale to conclude that SWC measures have positive impact on crop production. It has slight contribution to household income. Labour demand (household and hired) increase, level of inorganic fertilizer use decrease but use of organic fertilizer increase. Thus, it is worth to recommend that non-practiced households need to be aware about the advantages of conservation measures but with due consideration to challenges hindering adoption. SWC measures need to be integrated with other income generating activities. &nbsp; Key words: Impacts, Livelihood, practiced, non-practiced, household, adoption.

Emerging collectivity from the nuclear structure of Xe132 : Inelastic neutron scattering studies and shell-model calculations

Inelastic neutron scattering was used to study the low-lying nuclear structure of $^{132}\mathrm{Xe}$. A comprehensive level scheme is presented, as well as new level lifetimes, multipole mixing ratios, branching ratios, and transition probabilities. Comparisons of these data as well as previously measured $E2$ strengths and $g$ factors are made with new shell-model calculations for $^{132,134,136}\mathrm{Xe}$ to explore the emergence of collectivity in the Xe isotopes with $N&lt;82$ near the closed shell.

Two-Neutron Correlations in a Borromean $$\varvec{^{20}\mathrm{C}+n+n}$$ System: Sensitivity of Unbound Subsystems

The structure of $^{22}$C plays a vital role in the new physics at subshell closure of $N=16$ in the neutron-rich region. We study the two-neutron correlations in the ground state of the weakly-bound Borromean nucleus $^{22}$C sitting at the edge of the neutron-drip line and its sensitivity to ${\rm core}$-$n$ potential. For the present study, we employ a three-body (${\rm core}+n+n$) structure model designed for describing the Borromean system by explicit coupling of unbound continuum states of the subsystem (${\rm core}+n$). We use a density-independent contact-delta interaction to describe the neutron-neutron interaction and its strength is varied to fix the binding energy. Along with the ground-state properties of $^{22}$C, we investigate its electric-dipole and monopole responses, discussing the contribution of various configurations. Our results indicate more configuration mixing as compared to the previous studies in the ground state of $^{22}$C. However, they strongly depend upon the choice of the $^{20}{\rm C}$-$n$ potential as well as the binding energy of $^{22}$C, which call for new precise measurements for the low-lying continuum structure of the binary system ($^{20}{\rm C}+n$) and the mass of $^{22}$C. These measurements will be essential to understand the Borromean three-body system $^{22}$C with more accuracy.

To the Safety of Small Reservoirs Ground Structures

There are several hundred low-pressure soil structures, which belong to the IV and III classes of building on the territory of the Russian Federation. In recent years, the maintenance of normal operation and the maintenance of dams in satisfactory condition has become quite an acute problem. The decrease in the water objects’ security level of this kind is due to the long period of facilities’ operation, the reduction of the maintenance staff, the complete or partial lack of project documentation in this field and even the absence of owners. The main damaging factor in a hydrodynamic accident is a breakthrough wave. The flow of water moving at high speed damages to some extent buildings and structures, floods vast areas, and in the event of a breakthrough in a large reservoir, it can lead to the death of people. This article proposes constructive solutions that improve the safety of low-lying ground structures, and thus reduce the risk of accidents and flooding of the underlying areas.

Effect of Geranylgeraniol and Green Tea Polyphenols on High-fat-diet-induced Bone Deterioration in Male B6 Mice (P06-025-19)

ObjectivesTo investigate the combined effects of geranylgeraniol (GG, a 20-carbon isoprenoid found in fruits, vegetables, and grains) and green tea polyphenols (GTP, extracted from green tea) on high-fat-diet (HFD) induced bone deterioration in obese male mice. Our previous studies demonstrated that GG or GTP, when supplemented separately, was beneficial to the bone health of obese animals. Therefore, we hypothesized that GG combined with GTP would improve bone structure of obese mice fed a HFD. MethodsForty-eight male C57BL/6 J mice were assigned to 4 groups (n = 12/group) in a 2 (no GG vs. GG) × 2 (no GTP vs. GTP) factorial design: HFD, HFD + GG (400 mg GG/kg diet), HFD + GTP [0.5% (w/v) in drinking water], and HFD + GG + GTP. Animals were fed the respective diet ad libitum for 14 weeks. ResultsGTP supplementation, not GG, resulted in lower final body weight and greater fasting serum insulin concentrations. Supplementation of GG or GTP (separate, but not together) lowered blood glucose concentrations at 120 min. A decreased area under the curve of glucose tolerance tests and insulin tolerance test in the HFD + GG + GTP group was observed suggesting improved glucose clearance and insulin sensitivity, but no interaction was found between GG and GTP. Neither GG nor GTP affected serum concentrations of insulin or procollagen type I intact N-terminal (a bone formation marker). There was an interaction effect for serum concentrations of collagen type 1 cross-linked C-telopeptide (CTX, a bone resorption marker), resulting in HFD + GG + GTP being the lowest. Neither GG nor GTP supplementation affected the total area, bone area, and cortical thickness at the femur midshaft or the bone volume/total volume at the lumbar vertebrae. GG supplementation increased trabecular number and decreased trabecular separation at the lumbar vertebrae. GTP supplementation increased trabecular thickness at lumbar vertebrae. HFD + GG produced the greatest connectivity density and the lowest structure model index. ConclusionsThis study suggests a beneficial role of supplementing GG with GTP in bone health of obese animals. Funding SourcesThe study was supported by American River Nutrition to CLS and USDA ARS Project no. 3062-51,000-053-00D.

Crystal Structure Prediction via Basin-Hopping Global Optimization Employing Tiny Periodic Simulation Cells, with Application to Water-Ice.

A crystal structure prediction algorithm for use in periodic boundary conditions with empirical rigid models is presented, which employs (i) unrestricted cutoff radii for the real-space interactions, thus allowing the treatment of even very small unit cells, and (ii) a global-optimization algorithm based on the basin-hopping method of Wales et al. (D. J. Wales and J. P. K. Doye, J. Phys. Chem. A 1997, 101, 5111). The algorithm is then applied to the TIP4P model of water (W. L. Jorgensen et al., J. Chem. Phys. 1983, 79, 926.) in order to find the lowest enthalpy water-ice crystalline structures in the pressure region 0-8000 bar, in unit cells holding in the range of 1-16 molecules, and a database of the 10 lowest enthalpy structures found at pressures 0, 4000, and 8000 bar is presented. The algorithm finds many of the ice polymorphs and, in particular, finds that the lowest energy structure at zero pressure is almost exactly tied between an ice Ic (cubic ice) and ice Ih (hexagonal ice) structure, having near-identical energies.

Triaxiality in selenium-76

Background: Selenium and germanium nuclei are associated with both triaxiality and shape coexistence. The relative influence of these deformation effects on the low-lying nuclear structure remains the subject of much discussion with additional attention drawn to $^{76}\mathrm{Se}$ and $^{76}\mathrm{Ge}$ due to the potential for the observation of neutrinoless double-$\ensuremath{\beta}$ decay.Purpose: Experimental observables related to the deformation of $^{76}\mathrm{Se}$ are lacking in precision. The purpose of the present paper is to provide electric quadrupole matrix elements with improved precision in order to determine the deformation of low-lying states in a model-independent manner.Methods: Sub-barrier Coulomb excitation was employed at the reaccelerated beam facility of the National Superconducting Cyclotron Laboratory using the JANUS setup. Using this method nineteen $E2$ matrix elements were extracted.Results: Extracted matrix elements agree within uncertainties with those in the literature but with improved precision. Through both a comparison with geometric models and a model-independent evaluation of $E2$ matrix elements using rotational invariants, the ground state of $^{76}\mathrm{Se}$ is best described as having a significant triaxial component, but is not maximally triaxially deformed.Conclusions: Selenium-76 exhibits a significant degree of triaxiality in its ground state. A detailed comparison with configuration-interaction calculations indicates that this can be well reproduced theoretically.

Data on the structural coexistence in the 96Zr nucleus

On the brink of the phase transition from spherical to deformed Zr isotopes, 96Zr shows a co-existence of low-lying level structures with different degrees of quadrupole collectivity. Experimental data are available, but a coherent description of the measured properties is yet missing. This paper analyses available data and critically compiles the information relevant for the interpretation of the quadrupole-collective structure of 96Zr .

Institutional trust and misinformation in the response to the 2018–19 Ebola outbreak in North Kivu, DR Congo: a population-based survey

The current outbreak of Ebola in eastern DR Congo, beginning in 2018, emerged in a complex and violent political and security environment. Community-level prevention and outbreak control measures appear to be dependent on public trust in relevant authorities and information, but little scholarship has explored these issues. We aimed to investigate the role of trust and misinformation on individual preventive behaviours during an outbreak of Ebola virus disease (EVD). We surveyed 961 adults between Sept 1 and Sept 16, 2018. We used a multistage sampling design in Beni and Butembo in North Kivu, DR Congo. Of 412 avenues and cells (the lowest administrative structures; 99 in Beni and 313 in Butembo), we randomly selected 30 in each city. In each avenue or cell, 16 households were selected using the WHO Expanded Programme on Immunization's random walk approach. In each household, one adult (aged ≥18 years) was randomly selected for interview. Standardised questionnaires were administered by experienced interviewers. We used multivariate models to examine the intermediate variables of interest, including institutional trust and belief in selected misinformation, with outcomes of interest related to EVD prevention behaviours. Among 961 respondents, 349 (31·9%, 95% CI 27·4-36·9) trusted that local authorities represent their interest. Belief in misinformation was widespread, with 230 (25·5%, 21·7-29·6) respondents believing that the Ebola outbreak was not real. Low institutional trust and belief in misinformation were associated with a decreased likelihood of adopting preventive behaviours, including acceptance of Ebola vaccines (odds ratio 0·22, 95% CI 0·21-0·22, and 1·40, 1·39-1·42) and seeking formal health care (0·06, 0·05-0·06, and 1·16, 1·15-1·17). The findings underscore the practical implications of mistrust and misinformation for outbreak control. These factors are associated with low compliance with messages of social and behavioural change and refusal to seek formal medical care or accept vaccines, which in turn increases the risk of spread of EVD. The Harvard Humanitarian Initiative Innovation Fund.

Infrared spectroscopy of closed s-shell gas-phase M+(N2O)n (M = Li, Al) ion-molecule complexes

ABSTRACTWe present the results of a combined experimental and computational study of the structures of gas-phase M+(N2O)n (M = Li, Al) complexes. Infrared spectra were recorded in the region of the N2O asymmetric (N = N) stretch using photodissociation spectroscopy employing the inert messenger technique. Unlike in our previous studies on M+(N2O)n (M = Cu, Ag, Au and M = Co, Rh, Ir) complexes, N– and O–bound isomers in this case are near isoenergetic and are not distinguished spectroscopically at this resolution. In the case of Li+ complexes, there is, however, evidence for the presence of bound N2 moieties, indicating the presence of inserted, OLi+N2(N2O)n–type structures. The weak N2 band lies to the blue of the signature of molecularly N– and O–bound ligands and is well–reproduced in the simulated spectra of energetically low-lying structures computed from density functional theory. No such inserted isomers are observed in the case of Al+(N2O)n complexes whose infrared spectra can be understood on the basis of molecularly-bound N2O ligands. The differences in M+(N2O)n structures observed for these closed–shell, ns2, metal centres relative to other metal cations are discussed in terms of the likely bonding motifs.

Cluster structures in C12 from global energy density functionals

Spectroscopic properties of low-lying states and cluster structures in $^{12}$C are analyzed in a "beyond mean-field framework" based on global energy density functionals (EDFs). To build symmetry-conserving collective states, axially-symmetric and reflection-asymmetric solutions of the relativistic Hartree-Bogoliubov equations are first projected onto good values of angular momentum, particle number, and parity. Configuration mixing is implemented using the generator coordinate method formalism. It is shown that such a global microscopic approach, based on a relativistic EDF, can account for the main spectroscopic features of $^{12}$C, including the ground-state and linear-chain bands as well as, to a certain approximation, the excitation energy of the Hoyle state. The calculated form factors reproduce reasonably well the available experimental values, and display an accuracy comparable to that of dedicated microscopic cluster models.

The performance space measurement of regional innovation system based on neuropsychology

In this paper, the performance space measurement of regional innovation system was studied based on neuropsychology. Firstly, the neuropsychology and neural evolution theory were elaborated. Secondly, the genetic algorithm was used to design a regional enterprise performance space measurement model, and this was obtained by connecting the ERP production module and RBF neural network order forecast module. Finally, the algorithm and model constructed in this paper were used to predict the performance of regional foreign trade innovation system. Then, it is concluded that the model constructed in this paper includes the network with the lowest network structure complexity, the smallest training error and the least test error. Therefore, based on this premise, a good neural network that meets the actual needs of users can be obtained, which indicates that the improved method based on evolutionary neural network is effective to measure the performance of regional innovation system.

Hydration Effect on Positron Binding Ability of Proline: Positron Attachment Induces Proton-Transfer To Form Zwitterionic Structure.

The positron binding abilities of proline and its hydrated clusters were theoretically studied using multicomponent molecular orbital (MC_MO) calculations. Low-lying equilibrium structures of the neutral proline·(H2O) n ( n = 0-2) clusters were systematically explored with the aid of global reaction route mapping code. The positron binding energies were then calculated for the equilibrium structures. We found that the zwitterionic forms generally displayed high positron binding energies owing to their highly polar nature. We also found that nonzwitterionic forms can exhibit high positron binding energies if the addition of water significantly increases the total electric dipole moment. These results demonstrate that the most stable positron-bound proline·(H2O) n ( n = 1 and 2) structures are more stable than the most stable neutral structures, which implies that the attachment of a positron to a neutral hydrated proline cluster can induce structural changes if the positron-electron annihilation lifetime is sufficiently long relative to the time scale of nuclear motion. We also examined the influence of positron binding on the energy profiles of the proton transfer reactions from the nonzwitterionic form to the zwitterionic form.