Large Positive Slope Research Articles

Energetic Proton Distributions in the Inner and Middle Magnetosphere of Jupiter Using Juno Observations

AbstractJupiter is known to have a complex magnetosphere containing energetic (above 10s of keV) electrons, protons, and heavy ions. However, a global distribution of these energetic particles is not fully understood before the era of the polar‐orbiting Juno mission. In this study, we focus on the energetic proton distribution at M < 50 by taking advantage of Juno's measurement covering various magnetic latitudes and M‐shells, and find that energetic proton fluxes are higher off‐equator than that near the equator at M > ∼20, and become comparable or lower at high latitudes than those near the equator at low M‐shells. Pitch angle distributions of energetic protons are field‐aligned, isotropic, and weak pancake‐like from high to low M‐shells. Proton phase space density shows a weak M‐shell dependence at M > 30 and a large positive slope at M < 30, suggesting their potential source and loss processes.

Imaging paleoslabs and inferring the Clapeyron slope in D″ beneath the northern Pacific based on high-resolution inversion of seismic waveforms for 3-D transversely isotropic structure

We use waveform inversion to infer high-resolution 3-D models of the S-velocity perturbation δV S and the anisotropy parameter δξ in the lowermost 400 km of the mantle beneath the northern Pacific. Our inferred models show three prominent features: (i) a widespread positive δV S layer with ~100 km thickness that exists ~250 km above the core-mantle boundary (CMB), which could be due to a bridgmanite to post-perovskite phase transition related to the D″ discontinuity; (ii) distinct positive - δV S anomalies with positive δξ resolved from 100 km to more than 400 km above the CMB, which could be the subducted Izanagi, Farallon, and Telkhinia slabs; (iii) a vertically continuous low- δV S anomaly with negative δξ at the edge of the subducted slab, which we interpret as an upwelling plume induced by slab sinking. We infer the Clapeyron slope of the post-perovskite phase transition in the lowermost mantle beneath the northern Pacific to be 10.2 ± 1.3 MPa/K, based on the δV S gradient as a function of depth for the inferred 3-D V S structure. Our estimated large positive Clapeyron slope at the CMB suggests vigorous convection in the lowermost mantle. • We use waveform inversion to infer 3-D local V S and anisotropy structure in D″. • We image Izanagi, Farallon, and Telkhina slabs in D″ beneath the northern Pacific. • Hot upwelling plumes are forming at the edges of the descending cold slab. • Inferred Clapeyron slope is 10.2 ± 1.3 MPa/K in D″ beneath the northern Pacific.

A Longitudinal Study on Vocational Maturity Development using Growth Mixture Model: From Late Adolescence to Early Adulthood

본 연구에서는 고등학교 2학년부터 고등학교 졸업 후 4년이 지난 시점까지 진로성숙도의 변화를 성장혼합모형을 적용한 잠재계층분석을 통해 알아보고자 하였다.「한국교육종단연구2005」의 진로성숙도 자료를 분석한 결과, 후기 청소년기부터 초기 성인기까지의 진로성숙도 변화에 있어서 초기값이 가장 높고 작은 변화율로 성장하는 집단, 초기값은 중간이고 시간에 따라 변화하지 않는 집단, 초기값이 가장 낮고 큰 변화율로 성장하는 집단으로 세 개의 잠재계층이 존재하는 것을 확인할 수 있었다. 또한 잠재계층의 특성을 알아보기 위하여 가정배경, 개인 특성 및 경험, 진로계획, 고교 특성 및 경험, 진로활동 영역의 다양한 배경변수의 계층 간 차이를 분석하였다. 개인특성 및 경험 변수 중 성별과 자아개념, 교사관계 변수가, 진로계획 영역에서는 교육포부, 고교특성 및 경험에서는 동아리 활동, 진로활동과 관련해서는 고등학교 재학 중 진로와 직업 교과를 이수했는지 여부가 응답자의 잠재계층 분류에 영향을 미치는 것으로 나타났다.The purpose of this study was to investigate vocational maturity development from second grade of high school to four years after high school graduation through latent class analysis by applying growth mixture model. Results from analyzing 5th-, 7th-, 9th-wave data collected by Korean Educational Longitudinal Study(2005) suggested that three latent classes were found: class with high initial status and small positive slope, class with medium initial status and insignificant slope, and class with low initial status and large positive slope. Additionally, in order to explore characteristics of latent classes, differences in variables related to family backgrounds, personal characteristics and experiences, career plan, high school characteristics and experiences, and career-related activities were investigated. Variables including gender, self-concept, and relation with teachers, aspiration for education, club involvement while attending middle and high schools, whether the subject took career and vocation class while attending high school were found to affect classification of subjects into latent classes.

A Novel Frequency-Dependent Coupling With Flexibly Controllable Slope and Its Applications on Substrate-Integrated Waveguide Filters

This letter reports a novel realization of frequency-dependent coupling (FDC) structure, which can realize both the positive and negative slopes. The FDC is constructed by two coupled stepped-impedance grounded coplanar waveguides with opened ends. The characteristics of the FDC are studied, which indicates that the proposed FDC has advantages of the flexibly controllable slope, zero of position, and weak/strong strength. For the verification of the characteristics of the proposed FDC, an inline-line fourth-order substrate integrated waveguide bandpass filter (BPF) with one large positive slope and a third-order triplet BPF with one small negative slope for additional finite transmission zero with controllable position were designed, fabricated, and measured. Measured results agree well with simulated ones.

Plastic deformation modes in paramagnetic γ-Fe from longitudinal spin fluctuation theory

Abstract Using an efficient first-principles computational scheme, we calculate the intrinsic stacking fault energy ( γ i s f ) and the unstable stacking fault energy ( γ u s f ) of paramagnetic γ-Fe as a function of temperature. The formation energies are derived from free energies accounting for thermal longitudinal spin fluctuations (LSFs). LSFs are demonstrated to be important for the accurate description of the temperature-dependent magnetism, intrinsic and unstable stacking fault energies, and have a comparatively large effect on γ i s f of γ-Fe. Dominated by the magneto-volume coupling at thermal excitations, γ i s f of γ-Fe exhibits a positive correlation with temperature, while γ u s f declines with increasing temperature. The predicted stacking fault energy of γ-Fe is negative at static condition, crosses zero around 540 K, and reaches 71.0 mJ m−2 at 1373 K, which is in good agreement with the experimental value. According to the plasticity theory formulated in terms of the intrinsic and unstable stacking fault energies, twinning remains a possible deformation mode even at elevated temperatures. Both the large positive temperature slope of γ i s f and the predicted high-temperature twinning are observed in the case of austenitic stainless steels.

Brønsted versus Lewis Acid Type Anion Recognition by Arylboronic Acids.

Interactions between arylboronic acids and a series of anions as tetrabutylammonium salts in DMSO and MeCN were studied by (1)H and (11)B NMR as well as spectrophotometrically. Boronic acids act as Brønsted acid type receptors through hydrogen bonding with B(OH)2 hydroxyl groups toward Cl(-), Br(-), HSO4(-), and AcO(-), but they act as Lewis acid type receptors toward F(-) and H2PO4(-), which form tetrahedral adducts with the B(III) center of boronic acids, although there is also evidence for some contribution of hydrogen bonding with these anions. The Hammett plot for the binding constants of AcO(-) with 3- and 4-substituted phenylboronic acids in DMSO is nonlinear, with a small negative slope for electron-donating and weakly electron-accepting substituents and a large positive slope for strongly electron-accepting substituents. 3-Nitrophenylboronic acid recognizes zwitterions of amino acids in DMSO, and its UV absorption maximum undergoes a significant red shift in the presence of acetate anions, providing a means for sensing anions optically. Arylboronic acids as Brønsted acid type receptors show relatively low sensitivity to solvent polarity and are equally or even more efficient than widely employed proton donors such as ureas or dicarboxamides.

Generation of a direct-current, atmospheric-pressure microplasma at the surface of a liquid water microjet for continuous plasma-liquid processing

Plasmas at the surface of or inside liquids are of importance for emerging applications, and are often formed with stagnant liquids. Here, the authors present the generation of a direct-current, atmospheric-pressure microplasma at the surface of a liquid water microjet that enables solution species to be transported by forced convection. The water jet is formed by pumping conductive ionic solutions through a plastic capillary tube in a vertically falling geometry, and overcomes Plateau–Rayleigh instabilities by controlling the flow rate, resulting in a constant diameter jet of ∼0.45 mm over lengths of more than 30 mm. Analysis of the electrical characteristics of the complete microplasma-water jet system shows that the current–voltage (I-V) relationship is linear with a large positive slope when the solution conductivity is relatively low. The authors show that the primary contribution to this large resistance is the confined solution geometry. As proof-of-concept, the authors demonstrate that plasmonic Ag nanoparticles can be continuously produced at steady state from solutions of silver nitrate, opening up the possibility of scaled-up production of materials by plasma-liquid processes.

Evolution of the derivative skewness for high-amplitude sound propagation

The skewness of the first time derivative of a pressure waveform has been used as an indicator of shocks and nonlinearity in both rocket and jet noise data [e.g., Gee et al., J. Acoust. Soc. Am. 133, EL88–EL93 (2013)]. The skewness is the third central moment of the probability density function and demonstrates asymmetry of the distribution, e.g., a positive skewness may indicate large, infrequently occurring values in the data. In the case of nonlinearly propagating noise, a positive derivative skewness signifies occasional instances of large positive slope and more instances of negative slope as shocks form [Shepherd et al., J. Acoust. Soc. Am. 130, EL8–EL13 (2011)]. In this paper, the evolution of the derivative skewness, and its interpretation, is considered analytically using key solutions of the Burgers equation. This paper complements a study by Muhlestein et al. [J. Acoust. Soc. Am. 134, 3981 (2013)] that used similar methods but with a different metric. An analysis is performed to investigate the effect of a finite sampling frequency and additive noise. Plane-wave tube experiments and numerical simulations are used to verify the analytic solutions and investigate derivative skewness in random noise waveforms. [Work supported by ONR.]

Google search patterns suggest declining interest in the environment

Public interest in most aspects of the environment is sharply declining relative to other subjects, as measured by internet searches performed on Google. Changes in the search behavior by the public are closely tied to their interests, and those interests are critical to driving public policy. Google Insights for Search (GIFS) was a tool that provided access to search data but is now combined with another tool, Google Trends. We used GIFS to obtain data for 19 environment-related terms from 2001 to 2009. The only environment-related term with large positive slope was climate change. All other terms that we queried had strong negative slopes indicating that searches for these topics dropped over the last decade. Our results suggest that the public is growing less interested in the environment.

The heterocyclic ring of 4-substituted-1,8-naphthalimides is NOT inert to nucleophilic attack, contrary to earlier reports

The heterocyclic ring of N-aryl-4-chloro-1,8-naphthalimides, reported to be resistant to nucleophilic attack, reacts with primary amine nucleophiles at room temperature to give 4-chloro-N-alkyl-1,8-naphthalimides. The reaction is first order in the naphthalimide. The Hammett plot is linear (R(2) 0.996) with a large positive slope (+3.0), consistent with substantial negative charge development at nitrogen in the activated complex.

Thickness and Clapeyron slope of the post-perovskite boundary

The thicknesses and Clapeyron slopes of mantle phase boundaries strongly influence the seismic detectability of the boundaries and convection in the mantle. The unusually large positive Clapeyron slope found for the boundary between perovskite (Pv) and post-perovskite (pPv) (the 'pPv boundary') would destabilize high-temperature anomalies in the lowermost mantle, in disagreement with the seismic observations. Here we report the thickness of the pPv boundary in (Mg(0.91)Fe(2+)(0.09))SiO(3) and (Mg(0.9)Fe(3+)(0.1))(Al(0.1)Si(0.9))O(3) as determined in a laser-heated diamond-anvil cell under in situ high-pressure (up to 145 GPa), high-temperature (up to 3,000 K) conditions. The measured Clapeyron slope is consistent with the D'' discontinuity. In both systems, however, the pPv boundary thickness increases to 400-600 +/- 100 km, which is substantially greater than the thickness of the D'' discontinuity (<30 km). Although the Fe(2+) buffering effect of ferropericlase could decrease the pPv boundary thickness, the boundary may remain thick in a pyrolitic composition because of the effects of Al and the rapid temperature increase in the D'' layer. The pPv boundary would be particularly thick in regions with an elevated Al content and/or a low Mg/Si ratio, reducing the effects of the large positive Clapeyron slope on the buoyancy of thermal anomalies and stabilizing compositional heterogeneities in the lowermost mantle. If the pPv transition is the source of the D'' discontinuity, regions with sharp discontinuities may require distinct compositions, such as a higher Mg/Si ratio or a lower Al content.

From slow to superluminal propagation: Dispersive properties of surface plasmon polaritons in linear chains of metallic nanospheroids

We consider propagation of surface plasmon polaritons (SPPs) in linear periodic chains (LPCs) of prolate and oblate metallic spheroids. We show that the SPP group velocity can be efficiently controlled by varying the aspect ratio of the spheroids. For sufficiently small aspect ratios, a gap appears in the first Brillouin zone of the chain lattice in which propagating modes do not exist. Depending on the SPP polarization, the gap extends to certain intervals of the Bloch wave number $q$. Thus, for transverse polarization, no propagating SPPs exist with wave numbers $q$ such that ${q}_{c}^{\ensuremath{\perp}}&lt;|q|&lt;\ensuremath{\pi}/h$, $h$ being the chain period. For longitudinally polarized SPPs, the gap spans the interval $|q|&lt;{q}_{c}^{\ensuremath{\parallel}}$. Here ${q}_{c}^{\ensuremath{\perp}}$ and ${q}_{c}^{\ensuremath{\parallel}}$ are different constants, which depend on the chain parameters, spheroid aspect ratio, and its orientation with respect to the chain axis. The dependence of the dispersion curves on the spheroid aspect ratio leads to a number of interesting effects. In particular, bandwidth of SPPs that can propagate in an LPC can be substantially increased by utilizing prolate or oblate spheroids. When $q$ is close to a critical value, so that $|q\ensuremath{-}{q}_{c}^{\ensuremath{\perp}}|⪡\ensuremath{\pi}/h$ or $|q\ensuremath{-}{q}_{c}^{\ensuremath{\parallel}}|⪡\ensuremath{\pi}/h$, the decay length of the SPPs is dramatically increased. In addition, the dispersion curves acquire a very large positive or negative slope. This can be used to achieve superluminal group velocity for realistic chain parameters. We demonstrate superluminal propagation of Gaussian wave packets in numerical simulations. Both theory and simulations are based on Maxwell equations with account of retardation and, therefore, are fully relativistic.

FFLO Superconductivity near the Antiferromagnetic Quantum Critical Point

The Fulde–Ferrel–Larkin–Ovchinnikov (FFLO) state near the antiferromagnetic quantum critical point (AFQCP) is investigated by analyzing the two dimensional Hubbard model on the basis of the fluctuation exchange (FLEX) approximation. The phase diagram against the magnetic field and temperature is compared with that obtained in the BCS theory. We discuss the influences of the antiferromagnetic spin fluctuation through the quasiparticle scattering, retardation effect, parity mixing and internal magnetic field. It is shown that the FFLO state is stable in the vicinity of AFQCP even though the quasiparticle scattering due to the spin fluctuation is destructive to the FFLO state. The large positive slope d H FFLO /d T and the convex curvature (d 2 H FFLO /d T 2 > 0) are obtained, where H FFLO is the critical magnetic field for the second order phase transition from the uniform BCS state to the FFLO state. These results are consistent with the experimental results in CeCoIn 5 . The possible magnetic transition in the FFLO state is examined.

The Postperovskite Transition

The discovery of the postperovskite (PPv) transition has profound impact on our understanding of the core-mantle boundary (CMB) region. Unlike perovskite (Pv), the PPv phase has a layered structure of the SiO6octahedra, which may lead to a large contrast in some properties with Pv. Recent studies have proposed unusual properties of PPv, such as a large positive Clapeyron slope, a large sensitivity of the transition depth to iron, a decrease in bulk sound speed at the transition, and a development of significant lattice preferred orientation. Many of the proposed properties can provide explanations for the intriguing seismic observations at the CMB region. Yet significant discrepancies still exist. However, rapid developments in mineral physics will continue to improve our knowledge on the changes across the PPv transition.

Thermochemistry and high-pressure equilibria of the post-perovskite phase transition in CaIrO3

To study the ambient analog of the deep mantle MgSiO 3 perovskite to post-perovskite phase transition, high-temperature drop calorimetry experiments of perovskite and post-perovskite phases of CaIrO 3 system as well as high-pressure phase equilibrium experiments in the CaIrO 3 system were made. The enthalpies for dissociation of CaIrO 3 (298 K) to CaO + Ir + O2 (1573 K) were 486.7 ± 9.2 kJ/mol for post-perovskite and 454.5 ± 12.5 kJ/mol for perovskite. From the difference between them, the phase transition enthalpy from perovskite to post-perovskite at 298 K is -32.2 ± 15.5 kJ/mol. This gives 2.7 ± 15.6 kJ/mol as formation enthalpy of CaIrO 3 perovskite from CaO + IrO 2 at 298 K. Using the phase transition enthalpy and volume change of .0.48 ± 0.02 cm 3 /mol determined in this study, the phase equilibrium boundary is calculated to be P (GPa) = 0.040 T (K) - 67.1. The strongly positive slope agrees with that obtained in high-pressure experiments. This is consistent with a large positive Clapeyron slope of post-perovskite phase transition in MgSiO 3 recently reported from experimental and theoretical studies.

The trouble with seeing double

The recently discovered phase transition for (Mg,Fe)SiO3 from perovskite to post‐perovskite structure for pressure‐temperature conditions in the lowermost mantle provides a plausible mechanism to explain a several percent shear velocity increase detected at the top of the D″ region in many regions. The phase transition has a large positive Clapeyron slope, and given the likely presence of a strong temperature increase just above the core‐mantle boundary, D″ conditions may reintersect the phase boundary, resulting in a thin layer of perovskite below a lens of post‐perovskite, separated by a few percent velocity decrease. Detection of such a velocity decrease is shown to be much harder than detection of the shallower velocity increase due to fundamental properties of seismic waves; purported observations in support of a double‐discontinuity are re‐evaluated based on waveform modeling. Waveform stacking procedures are required for reliable detection of the lower half of any double‐crossing of the phase boundary.

Multipolar excitations in the antiferroquadrupolar phase of CeB 6

Abstract The hexaboride compound CeB 6 exhibits quadrupolar O xy type and magnetic order due to the four-fold degenerate Ce 3+ –Γ 8 CEF-states. The B - T phase diagram shows anomalous large positive slope of the critical field curve. This is due to a new type of induced octupolar T xyz order parameter. Inelastic neutron scattering experiments by Bouvet have provided direct evidence for the existence of collective excitations. Their nature is shown to be of mixed multipolar character and their dispersion and intensities are calculated using a RPA-type approach and a Holstein–Primakoff approach which show excellent agreement. Temperature and field dependence of the multipolar excitations are calculated and the latter is compared to experimental results.

On the preattentive accessibility of stereoscopic disparity: evidence from visual search.

We examined the generality of the claim that stereoscopic disparity is detectable in parallel across the visual field. Using a search paradigm with random-dot stereograms, we varied the relative disparity of target and distractor items. When both target and distractors had crossed disparities, both search functions (i.e., target in front of distractors and target behind distractors) were linear with positive slopes. When both target and distractors had uncrossed disparities, the pattern of results depended upon whether the target was in front of or behind the distractors-specifically, when the target was in front of the distractors, search functions were similar to those seen for "crossed" search, but when the target was behind the distractors, a nonlinear search function was found. Finally, when the target and distractors straddled the plane of fixation, a nonlinear search function was found when the target was in front of the distractors; however, when the target was behind the distractors, a linear search function with a large positive slope was found. We show that the nonlinear search functions are consistent with the effects of an intervening global surface percept. We also show that the size of the stimulus display may be a factor in some relative depth cases. Additionally, we replicate Steinman's (1987) finding that search is parallel when the distractors are located at the plane of fixation and the target disparity is crossed, eliminating monocular and spatial cues to target presence that may have been present in his original study. In a final control experiment, we showed that reaction times did not increase with set size when observers performed another kind of perceptual task on similar random-dot stereogram displays. This eliminates the possibility that some of the results obtained here can be explained by increases in the difficulty of perceiving/fusing the stimuli when the number of distractors is increased.

Thermoelectric power of Ce-based Kondo alloys

Abstract The Kondo lattice compounds CePdSn, CePdGa and CePtGa display pronounced anomalies in thermopower as a function of temperature, with a characteristic inverted tilda ( ∼ ) shape. We have attempted to correlate these anomalies with the dynamical susceptibility derived from inelastic neutron scattering. The TEP of CePdSb has a large positive slope, while that of CeRhSb shows a large peak at 20 K, signalling the onset of the Kondo insulator state.

Analysis of the current-voltage characteristic of the rf SQUID

The electrical equations of a resonant circuit fed with a radio-frequency current and inductively coupled to a weakly superconducting loop have been derived. The current-voltage characteristic of the rf superconducting quantum interference device can then be calculated and studied as a function of the junction resistance or of the resonance frequency, enabling its behavior to be better understood. As shown by Kurkijärvi, the large positive slope of the steps and the rounding of the characteristic result from thermal noise. However, in order to explain quantitatively the experimental results concerning, namely, point contact weak links which are generally oxidized or which have several contact points, it is useful to remark that the connection between the two superconductors constituting the Josephson junction may be made from n resistive paths. The mean thermal energy of the fluctuating flux is then close to nkbT instead of kbT if the inductances linking the contact points are large enough, that is, on the order of 10−11 H.