Qualitative Explanation In Terms Research Articles

Galaxy evolution in the metric of the cosmic web

The role of the cosmic web in shaping galaxy properties is investigated in the GAMA spectroscopic survey in the redshift range $0.03 \leq z \leq 0.25$. The stellar mass, $u - r$ dust corrected colour and specific star formation rate (sSFR) of galaxies are analysed as a function of their distances to the 3D cosmic web features, such as nodes, filaments and walls, as reconstructed by DisPerSE. Significant mass and type/colour gradients are found for the whole population, with more massive and/or passive galaxies being located closer to the filament and wall than their less massive and/or star-forming counterparts. Mass segregation persists among the star-forming population alone. The red fraction of galaxies increases when closing in on nodes, and on filaments regardless of the distance to nodes. Similarly, the star-forming population reddens (or lowers its sSFR) at fixed mass when closing in on filament, implying that some quenching takes place. Comparable trends are also found in the state-of-the-art hydrodynamical simulation Horizon-AGN. These results suggest that on top of stellar mass and large-scale density, the traceless component of the tides from the anisotropic large-scale environment also shapes galactic properties. An extension of excursion theory accounting for filamentary tides provides a qualitative explanation in terms of anisotropic assembly bias: at a given mass, the accretion rate varies with the orientation and distance to filaments. It also explains the absence of type/colour gradients in the data on smaller, non-linear scales.

Estimation of surface O3 from lower-troposphere partial-column information: Vertical correlations and covariances in ozonesonde profiles

Analysis of the spatial correlation of ozone mixing ratio in the vertical provides information useful for several purposes: (a) it aids description of the degree of regionality of the ozone transport-transformation processes, (b) the information provided in the form of a priori covariance matrices for remote retrieval algorithms can simplify and sharpen accuracy of the resulting estimates, and most importantly, (c) it allows a first evaluation of the improvement that remote retrievals can give over boundary-layer climatology. Vertical profiles of mean, variance, and vertical autocovariance, and vertical autocorrelation of ozone mixing ratios were estimated and given parameterizations. The WOUDC ozonesonde network database was used. During the years 2004–2006, these were considerably augmented by sondes taken by NASA, NOAA, and Canadian agencies during recent summertime intensive periods in North America. There are large differences across the North American continent in the patterns and magnitudes of correlation, especially in the lowest 2–3 km of the troposphere. This is especially significant for the near-surface layers (100's of meters deep) which determine actual surface O3 smog exposure and phytotoxicity, since satellite retrievals typically characterize at best a thick layer extending 3 km or more from the surface. The relative variation of O3 decreases in the vertical, particularly for the somewhat polluted launch stations, and this affects inference of surface O3 significantly. We outline a simple synthesis of mixed-layer and ozone-chemistry behavior to aid discussion of this and similar phenomena. Regional differences suggest broad if qualitative explanations in terms of larger-scale (interstate-transport) and local-scale phenomena (lake and sea breezes, degree/frequency of subsidence), inviting future study. The character of near-surface-to-full-layer covariance suggests that remote retrieval can describe surface ozone surprisingly well using 0–3 km partial-column ozone… for many situations. This indicates that there is substantial utility for new remote-retrieval methods that exploit ozone absorption in multiple wavelength regions, e.g., UV + Vis, UV + IR, or UV + Vis + IR. In summary, we find considerable value in interpreting retrievable O3 columns to estimate O3 quantities that are closely relevant to air pollution mitigation.

Tunable phase resonances in a compound metallic grating with perpendicular bumps and cuts

We propose a compound metallic grating with perpendicular bumps in each slit and investigate its transmission property theoretically. As the bumps are set symmetrically in the slits, the waveguide resonant peaks for the even (odd) modes exhibit a red-shift (blue-shift) compared with the resonant peaks of grating composed of bare slit. As the bumps are set asymmetrically, we show that the dips in transmission spectrum can be tuned by shifting the position and changing the size of bumps in the slit. The corresponding physical mechanisms for above phenomenon are discussed, followed by some qualitative explanations in terms of field distribution. We also investigate the optical transmission through a compound metallic grating with perpendicular bumps in one slit and cuts in another slit, and find that the dips in transmission spectrum are more sensitive to the simultaneous change of the bumps and cuts.

The vibrational spectrum of thiazole between 600 and 1400 cm −1 revisited: A combined high-resolution infrared and theoretical study

The Fourier transform infrared gas-phase spectrum of thiazole, C 3H 3NS, has been recorded in the 600–1400 cm −1 wavenumber region with a resolution around 0.0030 cm −1. Nine fundamental bands ( ν 5(A′) to ν 11(A′), ν 15(A″), and ν 16(A″)) are analysed employing the Watson model. Ground-state rotational and quartic centrifugal distortion constants as well as upper state spectroscopic constants have been obtained from the fits. A detailed analysis of perturbations identified in the ν 11(A′) band at 866.5 cm −1 enables a definitive location of the very weak ν 10(A′) and ν 14(A″) bands at 879.3 and 888.7 cm −1, respectively. The three levels are analysed simultaneously by a model including Coriolis resonance using an ab initio predicted first order c-Coriolis coupling constant; second and higher order Coriolis parameters are determined. Qualitative explanations in terms of Coriolis resonances are given for a number of crossings observed in ν 5(A′), ν 6(A′), and ν 7(A′) at 1383.7, 1325.8, and 1240.5 cm −1, respectively. The rotational constants, anharmonic frequencies, and vibration–rotation constants (alphas, α ν A , B , C ) calculated by quantum chemical calculations using a cc-pVTZ and TZ2P basis with B3LYP methodology, have been compared with the present experimental data. The rotation constant differences for each vibrational state, from the ground state values, are closer to experiment from the TZ2P calculations relative to those using cc-pVTZ. The values for Δ J, Δ JK, Δ K, δ J, and δ K are close to experiment with both basis sets.

Effects of morphology and optical contrast in organic distributed feedback lasers

Optically pumped organic distributed feedback lasers, based on the same cavity geometry and polymeric active material, but patterned with different methods, are compared. In one case, the pattern is transferred into the polymer by spin coating the latter on top of a silica master. In the other case, the master is used as a mold to imprint a polymer film. The comparison shows that the imprinted structures, even though a lower quality copy of the master at morphological level, exhibit better performance. This result is checked for different laser cavities, and a qualitative explanation in terms of optical contrast is provided.

Variable trends in R-X bond dissociation energies (R = Me, Et, i-Pr, t-Bu).

[structure: see text] High level ab initio molecular orbital calculations confirm experimental indications that the effect of alkyl substituents (R = Me, Et, i-Pr, t-Bu) on R-X bond dissociation energies varies considerably according to the nature of X. A simple qualitative explanation in terms of valence-bond theory is presented, highlighting the increasing importance of the stabilization of R-X by the ionic R(+)X(-) configuration for electronegative X substituents (such as F, OH, and OCH(3)).

B211 鉛直管内上昇乱流場における単一気泡の挙動

Quasi-equilibrium radial position of a single bubble in turbulent upflow in a vertical tube were experimentally investigated. The liquid phase was water of several temperatures and the range of bubble size was 0.35-3.8mm. It was suggested that the bubble whose diameter is approximately smaller than 1mm is more probably located in the center part in the tube, while the bubble approximately larger than 1.5mm migrates towards the wall; we call these bubbles coring and sliding bubbles, respectively. The critical bubble size for the transition from coring to sliding bubbles increased with the increase of liquid flowrate but it was not significantly affected by the water temperature. A qualitative explanation in terms of lift force and drag force was given for these results.

Indium adsorption at the surface of liquid In+Ga alloy electrodes in contact with an aqueous 1 M NaClO4 solution

Abstract The surface charge densities of liquid In+Ga alloy electrodes with indium bulk contents ranging from 0 to 16.5 mol% were obtained as functions of the electrode potential by means of dropping microelectrode charging current and ac impedance measurements in aqueous 1 M NaClO4 solutions of varied pH at 32°C. Using surface tension literature data of liquid In+Ga in vacuum and quasi-chemical multilayer model calculations they were integrated to electrocapillary curves. From the latter, the dependences of the indium surface excess on alloy composition, electrode potential and charge density were derived. A strong indium adsorption was found in the entire accessible range of bulk compositions. It extends over several atomic surface layers and can be accounted for by the surface tension difference between pure liquid gallium and indium, combined with the positive heat of mixing of the liquid In+Ga alloy system. It is shown that the indium surface excess decreases if the electrode potential or surface charge density is made more negative. A qualitative explanation in terms of pure component work function differences is given.

Influence of the adsorption phenomena on the NPP and RPP limiting currents for labile metal-macromolecule systems

Abstract The impact of adsorption effects on limiting currents obtained in reverse pulse (RPP) and normal pulse polarography (NPP) is analysed critically for induced reactant adsorption systems with any ligand to metal ratio. Qualitative explanations in terms of the concentration profiles are provided. We demonstrate that, for labile systems, no influence on the RPP limiting current can be found from the complex adsorption. However, ligand adsorption increases the RPP limiting current, this influence decreasing as the total metal concentration decreases. So, RPP normalised limiting current values ( φ ) are suggested to improve the fitting of the stability constant at very low total metal concentrations. If the total ligand concentration is chosen for maximum sensitivity, the remaining effect of the ligand adsorption leads to a bias in the stability constant of less than 14%, provided that the diffusion coefficient of the complex and ligand is 20-fold lower than the diffusion coefficient of the metal ion. Because the limiting NPP and RPP currents are equal for any ligand to metal ratio and without adsorption, approximate expressions derived for NPP facilitate the determination of the stability constant from the φ versus total metal concentration plot. This procedure is applied to some experimental results of Zn and Cd complexed with poly(methacrylic) acid.

Mixed-Valent Diruthenium Long-Chain Carboxylates. 2. Magnetic Properties.

The magnetic properties of several mixed-valent diruthenium long-chain carboxylates of general formula Ru(2)(RCO(2))(4)X (X = Cl, DOS, or RCO(2), DOS = dodecyl sulfate, and RCO(2) = linear aliphatic carboxylate or dialkoxy- or trialkoxybenzoate) were studied in the temperature range 6-400 K. All of the compounds exhibit a strong zero-field splitting (D = ca. 75 cm(-)(1)), independent of the nature of the axial anion X or of the equatorial substituent R. In the X = RCO(2) series an intermolecular antiferromagnetic (AF) interaction zJ = ca. -2 cm(-)(1) was found, whereas in the case of an X = DOS analogue, this interaction is very weak (-0.2 cm(-)(1)). The X = Cl series shows three distinct types of interdimer magnetic exchange: very weak, moderate (|zJ| approximately 2 cm(-)(1)), or strong (|zJ| > 10 cm(-)(1)). One representative complex in this series, Ru(2)(C(4)H(9)CO(2))(4)Cl, has been structurally characterized by X-ray crystallography. Crystal data: tetragonal system, space group I&fourmacr;2d, a = 14.137(3) Å, c = 26.246(5) Å, and Z = 8. Examination of the structures and magnetic behaviors suggests that the AF exchange in this series correlates with the Ru-Cl-Ru intermolecular angle; a qualitative explanation in terms of overlap of magnetic orbitals is proposed. Magnetic susceptibility measurements in the columnar mesophase of the mesomorphic congeners indicate that no significant structural change occurs at the crystal-liquid crystal transition.

‘‘Spin’’ splitting in asymmetric double quantum wells: A mechanism for ‘‘spin’’-dependent hole delocalization

We show how the breakdown of Kramers degeneracy for spin-orbit coupled bands in asymmetric double quantum wells may give rise to a new mechanism for tunneling which does not require resonant conditions. The most interesting aspect of this finding is that, in this case, there is a ``spin''-dependent delocalization of the wave function, leading to preferential tunneling of one ``spin'' state. We relate this effect to the symmetry properties of the wave functions of both single and asymmetric double quantum wells, and provide a qualitative explanation in terms of perturbation theory.

Adsorbate Induced Surface Reconstruction on W(100)

We have studied a hydrogen induced structural phase transition on a W(100) surface. The surface atoms on a clean W(100) are displaced along the ⟨11⟩ direction. Hydrogen adsorption tends to switch the displaced surface atoms along the ⟨10⟩ direction. We discuss the nature of this transition, present Monte Carlo simulation results as well as give qualitative explanation in terms of competing anisotropy fields.

Plasticity and space distribution of the phases in an iron/silver two-phase material

In order to check the influence of the space phase distribution on the overall plastic behaviour of microinhomogeneous materials, a study of an iron/silver aggregate has been undertaken. The first results show a strong influence of phase concentration on the yielding and plastic flow stages. A qualitative explanation in terms of phase connectivity is proposed for yielding and a systematic discrepancy between a two-phase self-consistent model prediction and the experimental results is established for the plastic flow stage.

Dynamics of the order parameter of superfluid phases of helium-3

The spin dynamics and the orbital dynamics in the A and B phases of superfluid 3He are analyzed. Attention is focused on solitons and instantons: nonsingular configurations of the field of the order parameter of the 3He superfluid phases. A qualitative explanation in terms of solitons and instantons is offered for several experiments involving the A and B phases of 3He. The analysis of these questions is prefaced by some general information on the order parameter and the free energy in superfluid 3He.

Semi-empirical models for the electric field gradient in metals

A survey over the present state of the empirical investigation of the electric field gradient at the nuclear site of impurity atoms and of matrix atoms in noncubic metal matrices is given. A qualitative explanation in terms of the electronic charge distribution typical for the host's group in the periodic system of elements is discussed. For group IIb hosts, two semi-empirical models which were developed in Bonn are described in more detail, i.e. the ‘naive model’ and the ‘Thomas-Fermi model’.

Angular distributions of Sc fragments from the interaction ofU238with 0.8-400 GeV protons

Angular distributions of $^{44}\mathrm{Sc}^{m}$, $^{46}\mathrm{Sc}$, $^{47}\mathrm{Sc}$, and $^{48}\mathrm{Sc}$ emitted in the interaction of $^{238}\mathrm{U}$ with 0.8, 3.0, 11.5, and 400 GeV protons have been measured. The angular distributions peak at forward angles at 0.8 and 3 GeV but are sideward-peaked at 11.5 and 400 GeV. At 400 GeV, fewer fragments are emitted at forward than at backward angles. Isotopic differences were found to be small. The data were fitted with the function ${F}_{L}({\ensuremath{\theta}}_{L})=1+{A}_{1}{cos\ensuremath{\theta}}_{L}+{A}_{2}{{cos}^{2}\ensuremath{\theta}}_{L}$ and were also analyzed in terms of the two-step model. The values of ${A}_{1}$ peak at 3 GeV, go through zero at 11.5 GeV, and become negative at 400 GeV. The values of ${A}_{2}$ are zero at 0.8 GeV and become increasingly negative with increasing proton energy. A qualitative explanation in terms of a possible change in the nature of proton-nucleus interactions at high energies is presented.

Effect of morphological structure on photosensitivity of chemically deposited PbS thin films

Chemically deposited PbS thin films have been prepared for use as infrared detectors. A systematic and elaborate study using scanning electron microscopy shows that the structure and crystallite size are related to the photosensitivity. Both the role of chemical oxidant influencing the type of conductivity and morphological details such as crystallite size distribution have been investigated. It is observed that in the absence of oxidant the average size of crystallites is about 0.9 mu m. This decreases to 0.3 mu m for the concentration of oxidant imparting maximum photosensitivity and further reduces to 0.2 mu m or less at higher concentrations. A good photosensitive film is electronically p-type and has a more uniform crystallite size distribution with relatively loose compact structure. Annealing of the films at 393K under vacuum (5*10-2 Torr) for 4-5 h affects the electronic properties considerably but does not cause any appreciable change in the structure except in smoothing the grain boundaries to a certain extent. A qualitative explanation in terms of rate of chemical reaction is offered for the morphological parameters observed in these experiments. It is also suggested that the photocharacteristics could be viewed partly as a support for barrier modulation but having its origin in the physical nature of the films.

Effect of pre-soak and dissolved gas content on craze nucleation and creep of poly(methyl methacrylate) in methanol

Craze nucleation and growth in stressed poly(methyl methacrylate) exposed to a methanol environment is strongly influenced by any exposure to that environment before application of the stress. It is also significantly influenced by the dissolved gas content of the methanol. It is demonstrated that increased exposure to methanol prior to application of the creep stress results in a decreased craze density and there exists a critical pre-soak time after which no crazes are nucleated. The critical pre-soak time is a function of dissolved gas content and creep stress. The variation in creep response is examined and a qualitative explanation in terms of fluid penetration is proposed.

Compounds and pseudo-binary alloys with the CuAl 2 ( C16)-type structure II. Theoretical discussion of crystallographic parameters

A qualitative explanation in terms of band structure effects is given for the observed oscillatory dependence of the c a ratio of C16-type compounds and alloys on the concentration of valence electrons. The fact that the x-parameter more or less follows the oscillations in the c a ratio is explained in a semi-quantitative way with the help of a model that considers the atoms as elastic balls.

Non-velocity Redshifts and Photon–Photon Interactions

RECENT data on galactic redshift anomalies have led Hoyle and Narlikar1, for example, to propose a qualitative explanation in terms of spatio-temporal variation of proper mass. The consequences of hypotheses such as this are evidently worthy of study, but there are other redshift anomalies, which should also be considered in this context. A possible alternative explanation is in terms of an inelastic photon–photon interaction; this has the advantages of being more inclusive, more quantitative (at least in order of magnitude) and immediately testable in the laboratory.