Field-dependent Effects Research Articles

The Effect of Field Dependence on Repurchase Intention: The Moderating Effect of Satisfaction

<p>在探討場地依賴對學習成效和表現之影響、及其後續之消費行為的研究中，大多以實體教學環境為研究情境，而欠缺以虛擬教學環境為研究情境背景。本研究以近一年內曾經參與過補教業線上語言學習平台之人士為研究對象，探討消費者之場地依賴與其再購意願之關係，及滿意度對上述關係的中介效果。本研究以網路電子問卷採便利抽樣方法收集資料，樣本來源包含Facebook、Google等社群平台使用者，共收集221份有效樣本。分析結果顯示，消費者之場地依賴與其再購意願為顯著正相關，滿意度為上述關係之部分中介變數，本研究的所有假說都獲得支持。根據研究結果，本研究提出理論與管理意涵。</p> <p> </p><p>Research on the effects of field dependence on learning output and outcome, and the following consumer behavior, has mainly been conducted in the context of physical environment of learning. Little research has been conducted in the context of virtual environment. Using customers who have learned language online within one year before this study as subjects, this study investigates the relationship between field dependence and repurchase intention, and the moderating effect of satisfaction on the above relationship. An online questionnaire was distributed to users of Facebook and Google communities by convenience sampling method. A total of 221 valid responses are collected. The results show that field dependence is positively and significantly related to repurchase intention, and satisfaction is a partial mediator of the relationship between field dependence and repurchase intention. All of the hypotheses are supported. The managerial and theoretical implications of the results are discussed.</p> <p> </p>

Tuning of memory effect with magnetic field of Ni and Co-doped ferrite-PbZr0.58Ti0.42O3 nanocomposite

The magnetoelectric nanocomposite Ni0.5Co0.5Fe2O4-PbZr0.58Ti0.42O3, having a weight ratio of 3:7, has been fabricated through a low temperature “Pyrophoric reaction process”. The structural and surface characterizations of the composite have been established by the X-ray diffraction technique and scanning electron micrographs, respectively. The magnetic field dependent electrical memory effect has been examined by the study of direct current electrical characterization of the composite at room temperature. In an applied magnetic field, the open circuit current increases by 21 % at room temperature. The current versus voltage characteristic of the nanocomposite expresses non-Ohmic behavior and follows the Child’s Law. For alignment of the magnetic dipoles of the piezo-magnetic phase of the magnetoelectric composite with a space charge effect, the current increases with the applied magnetic field, where the maximum change is found to be ∼28 % in the measured range. The maximum value of the magneto-capacitance has been noted as ∼5 % for the low frequency region.

PENETRATIVE THERMO-GRAVITATIONAL AND SURFACE-TENSION DRIVEN CONVECTION IN A FERROFLUID LAYER THROUGH VOLUMETRIC INTERNAL HEATING WITH VARIABLE VISCOSITY

This work pertaining to analytical and numerical studies on FTC in a FF layer with impact of coupled buoyancy-gravitational and surface-tension forces through the strength of internal heat source on the system subjected to the magnetic field dependent (MFD) viscosity effect. The lower boundary is considered to be rigid at either conducting or insulating to temperature perturbations, while upper boundary free open to the atmosphere is flat and subject to a Robin-type of thermal boundary condition. The Rayleigh-Ritz method with Chebyshev polynomials of the second kind as trial functions is employed to extract the critical stability parameters numerically. The onset of FTC is delayed with an increase in MFD (  ) parameter and Biot number ( Bi ) but opposite is the case with an increase in Rayleigh number( M1 ), non-linearity of fluid magnetization ( M 3 ) and strength of internal heat source ( Ns ). Their effects are complementary in the sense that the critical Mac and Rmc decrease with an increase in Rt .

The magnetic field dependent displacement effect and its correction in reference and relative dosimetry

Objective. This study investigates the perturbation correction factors of air-filled ionization chambers regarding their depth and magnetic field dependence. Focus has been placed on the displacement or gradient correction factor Additionally, the shift of the effective point of measurement that can be applied to account for the gradient effect has been compared between the cases with and without magnetic field. Approach. The perturbation correction factors have been simulated by stepwise modifications of the models of three ionization chambers (Farmer 30013, Semiflex 3D 31021 and PinPoint 3D 31022, all from PTW Freiburg). A 10 cm × 10 cm 6 MV photon beam perpendicular to the chamber’s axis was used. A 1.5 T magnetic field was aligned parallel to the chamber’s axis. The correction factors were determined between 0.4 and 20 cm depth. The shift of from the chamber’s reference point was determined by minimizing the variation of the ratio between dose-to-water and the dose-to-air along the depth. Main Results. The perturbation correction factors with and without magnetic field are depth dependent in the build-up region but can be considered as constant beyond the depth of dose maximum. Additionally, the correction factors are modified by the magnetic field. at the reference depth is found to be larger in 1.5 T magnetic field than in the magnetic field free case, where an increase of up to 1% is observed for the largest chamber (Farmer 30013). The magnitude of for all chambers decreases by 40% in a 1.5 T magnetic field with the sign of remains negative. Significance. In reference dosimetry, the change of in a magnetic field can be corrected by applying the magnetic field correction factor when the chamber is positioned with its at the depth of measurement. However, due to the depth dependence of the perturbation factors, it is more convenient to apply the -shift during chamber positioning in relative dosimetry.

Effects of localization length and spatial disorder on a charge carrier mobility in organic disordered semiconductors

We investigate the transport properties of charge carrier disordered organic semiconductors with a focus on the determination and analysis of charge carrier mobility. By understanding that charge transport is due to incoherent hopping of charge carriers across localized states, we use a model that relates mobility to charge carrier (not small polarons) hopping by thermal activation. We consider the Miller–Abrahams expression to describe the hopping rate of charge carriers and employ kinetic Monte Carlo simulation methods to generate data from which we can analyze charge carrier mobility as a function of applied electric field, temperature, localization length, and spatial and energetic disorder parameters. Based on our results, we discuss the effects of these parameters on charge carrier mobility. Our results show the importance of the spatial disorder parameter and localization length in the effects of electric field dependence on charge carrier mobility, and we also evaluate the value of localization length that has been mostly considered as 0.1b, where b is the lattice parameter.

Poling magnetic field dependence and memory effect of magnetoelectric coupling in honeycomb antiferromagnet cobalt niobate

We have firstly studied the poling magnetic field dependence of magnetoelectric (ME) coupling in a honeycomb antiferromagnet Co4Nb2O9, and found that the ME susceptibilities do not increase monotonously with increasing the poling magnetic field strength (HPole) as the usual case, but reach maxima around 10 kGs. This phenomenon results from opposite HPole dependences of domain wall thickness and energitically preferred domain's proportion. More interestingly, if the sample returns to paramagnetic phase after being poled and then reenters antiferromagnetic phase without being poled, ME coupling still exists. This memory effect is attributed to the presence of ME domain nucleation centers in paramagnetic phase.

Phase diagram for strongly interacting matter in the presence of a magnetic field using the Polyakov–Nambu–Jona-Lasinio model with magnetic field dependent coupling strengths

We study the phase diagram for strongly interacting matter using the 't Hooft determinant extended Nambu--Jona-Lasinio model with a Polyakov loop in the light and strange quark sectors (\emph{up}, \emph{down} and \emph{strange}) focusing on the effect of a magnetic field dependence of the coupling strengths of these interactions. This dependence was obtained so as to reproduce recent lattice QCD results for the magnetic field dependence of the quarks dynamical masses. A finite magnetic field is known to induce several additional first-order phase transition lines with the respective Critical End Points (CEP) in the temperature-quark chemical potential phase diagram when compared to the zero magnetic field case. A study of the magnetic field dependence in the range $eB=0-0.6~\mathrm{GeV}^2$ of the location of these CEPs reveals that the initial one as well as several of the new ones only survive up to a critical magnetic field. Only two remain in the upper limit of the studied magnetic field strength. A comparison of the results obtained with versions of the model with and without Polyakov loop is also done. We also found that the inclusion of the magnetic field dependence on the coupling strengths, while not changing the qualitative features of the phase diagram, affects the location of these CEPs. The comparison of results with and without a regularization cutoff in the medium part of the integrals does not show a significant change.

Dampak Visual Complexity Terhadap Minat Beli Konsumen dalam Bisnis Ritel

Abstract. Along with the rapid economic growth in Indonesia, high buying power led to significant emergence of new-comers brand in retail market. Bottled tea business that used to dominated by two brands, now become highly competitive with more than 20 brands in the market, also an increase in chocolate consumption by more than 25 percent per year making chocolate display in supermarkets become remarkably widespread. This is challenge for manufacturers and retailers to develop strategy to gain maximum profit. This research aims to analyze the effect of display's visual complexity on consumers evaluation process and purchase intention. This research also analyzes the effect of consumer field dependence and shopping goal on perceived target attractiveness. This research consists of 3 experimental studies, each in ANOVA 2x2. Study 1 analyze abstract stimuli, study 2 analyze real product and study 3 complements with eye tracking data. The results prove that the more complex is the product's display, the more product target attractiveness will be rated lower, especially for utilitarian customer with field dependent character. Keywords: Package, processing fluency, purchase intention, retail, visual complexity

Temperature-Driven Pinned Layer Magnetization Reversal in Exchange Biased Fe₃O₄/Alq₃/Co/CoO Hybrid Spin Valve

In this article, we provide an initial qualitative description of the basic magnetization reversal processes behind temperature and cooling field-dependent exchange bias effect at Co/CoO interface of Fe3O4/Alq3/Co/CoO/Au hybrid spin valve (SV) device structure. The exchange field at Co/CoO interface is observed to be inversely proportional to temperature, indicating enhanced magnetic field sensitivity of Co reverse domain nucleation at the high-temperature region. The exchange field, at constant temperature, is found to be insensitive to change in the cooling field, which may be due to efficient ferromagnetic coupling at the Co/CoO interface of the device. Sudden decrease of exchange field with training cycle number ( $n$ ) has been observed at lower values of $n$ , which may be attributed to rearrangement of Co pinned layer spin configuration toward equilibrium. Interestingly, incorporation of antiferromagnetic CoO layer has not been observed to bring any change in magnetoresistance (MR) behavior of the exchange biased SV device, which shows a two-step switching pattern of MR at 100 K.

Temperature and magnetic field dependent Raman study of electron-phonon interactions in thin films of Bi2Se3 and Bi2Te3 nanoflakes

We have investigated two-dimensional nanostructures of the topological insulators ${\mathrm{Bi}}_{2}{\mathrm{Se}}_{3}$ and ${\mathrm{Bi}}_{2}{\mathrm{Te}}_{3}$ by means of temperature and magnetic field dependent Raman spectroscopy. The surface contribution of our samples was increased by using thin films of dropcasted nanoflakes with the aim of enhancing their topological properties. Raman spectroscopy provides a contact-free method to investigate the behavior of topological properties with temperature and magnetic fields at lower dimensions. The temperature dependent Raman study reveals anharmonic phonon behavior for ${\mathrm{Bi}}_{2}{\mathrm{Te}}_{3}$ indicative of a two-phonon relaxation mechanism in this material. Contrary to this, ${\mathrm{Bi}}_{2}{\mathrm{Se}}_{3}$ shows clear deviations from a two-phonon anharmonic decay model at temperatures below 120 K exhibiting a hardening and broadening, especially of the ${A}_{1\text{g}}^{2}$ mode. Similarly, the magnetic field dependent self-energy effects are only observed for the ${A}_{1\text{g}}^{2}$ mode of ${\mathrm{Bi}}_{2}{\mathrm{Se}}_{3}$, showing a broadening and hardening with increasing field. We interpret our results in terms of corrections to the phonon self-energy for ${\mathrm{Bi}}_{2}{\mathrm{Se}}_{3}$ at temperatures below 120 K and magnetic fields above 4 T due to electron-hole pair excitations associated with the conducting surface states. The phonon renormalization with increasing magnetic field is explained by a gap opening in the Dirac cone that enables phonon coupling to the changing electric susceptibility.

High-performance optoelectronic devices based on van der Waals vertical MoS2/MoSe2 heterostructures

Monolayer MoS2 is a direct band gap semiconductor with large exciton binding energy, which is a promising candidate for the application of ultrathin optoelectronic devices. However, the optoelectronic performance of monolayer MoS2 is seriously limited to its growth quality and carrier mobility. In this work, we report the direct vapor growth and the optoelectronic device of vertically-stacked MoS2/MoSe2 heterostructure, and further discuss the mechanism of improved device performance. The optical and high-resolution atomic characterizations demonstrate that the heterostructure interface is of high-quality without atomic alloying. Electrical transport measurements indicate that the heterostructure transistor exhibits a high mobility of 28.5 cm2/(V·s) and a high on/off ratio of 107. The optoelectronic characterizations prove that the heterostructure device presents an enhanced photoresponsivity of 36 A/W and a remarkable detectivity of 4.8 × 1011 Jones, which benefited from the interface induced built-in electric field and carrier dependent Coulomb screening effect. This work demonstrates that the construction of two-dimensional (2D) semiconductor heterostructures plays a significant role in modifying the optoelectronic device properties of 2D materials.

Exchange bias in Fe/Ir20Mn80 bilayers: Role of spin-glass like interface and ‘bulk’ antiferromagnet spins

We have performed magnetic measurements such as temperature (T), cooling field (μ0HFC) dependence and training effect of exchange bias (EB) to investigate the magnetic nature of the interface in the Fe/Ir20Mn80 system. Bilayers of different thicknesses of Ir20Mn80 (antiferromagnetic) have been prepared by dc magnetron sputtering at room temperature. The variation of exchange bias field (μ0HEB) with Ir20Mn80 thickness indicates that the ‘bulk’ spins of the antiferromagnet contribute to EB. Exponential decay of μ0HEB and coercive field (μ0HC) with T reveals the possible presence of a spin glass (SG) like interface. The decrease of μ0HEB with increasing μ0HFC provides further evidence of SG like behaviour at the interface. The results of training effect data indicate the presence of frozen and rotatable spins at the magnetically frustrated interface of these Fe/Ir20Mn80 bilayers.

Tunneling magnetoresistance of hydrothermally sintered La1-Sr MnO3-silica nanocomposites

Abstract The study deals with tunneling magnetoresistance in a series of composite systems of so-called 0–3 connectivity, in which highly conducting manganite nanoparticles of ferromagnetic groundstate (0-dim objects) are embedded in the (3-dim) insulating matrix of silica. The sample fabrication included the sol-gel preparation of La1–xSrxMnO3 particles of the x = 0.35 composition and 25 nm mean crystallite size, their coating by silica of controlled thicknesses in the 1–5 nm range, and subsequent consolidation by hydrothermal sintering at 300 °C. Temperature dependent electric resistivities of the materials were measured in magnetic fields of 0 and 40 kOe down to 5 K, and field-dependent isothermal curves were taken by sweeping magnetic field up to 140 kOe. The field-dependent effects were interpreted in terms of the low- and high-field magnetoconductance. It is important that extents of these phenomena are markedly independent of the silica amount, despite the five orders change in absolute resistivity values. Microscopic mechanisms of the intergrain transport, applicable to polycrystalline manganites, nanogranular compacts and nanocomposites in general, are proposed.

Large anomalous Nernst effect across the magneto-structural transition in a bulk Ni-Co-Mn-Sn full Heusler alloy

We report on the observation of a temperature and field dependent anomalous Nernst effect (ANE) in a Ni-rich bulk Ni-Co-Mn-Sn full Heusler alloy. A large change in the transverse Nernst coefficient (N) is obtained across the first order magneto-structural transition from a tetragonal martensite to a cubic austenite phase. The saturation fields of both the ANE and the magnetization appear to depend largely on the magnetic anisotropy of the device. Such a change in the Nernst co-efficient may prove to be useful for switching applications controlled by temperature and magnetic field changes.

Influence of spin fluctuations on the magnetocaloric behavior of Gd2Co3Al9 compound

Arc melted Gd2Co3Al9 compound crystallizes in orthorhombic Y2Co3Ga9 structure type (space group Cmcm, No. 63) as single phase. The magnetization M(T), specific heat C(T) and the resistivity ρ(T) measurements reveal an antiferromagnetic transition at 9.6 K. The temperature dependence of magnetic entropy change, -ΔSM(T), calculated from the M(B) data, gives a maximum value of entropy change -ΔSMMax=6.3J/kg.K for a field change of 0–7 T in a broad temperature range of ΔT=32K above the magnetic ordering temperature. B2 dependence of magnetic field dependent magnetocaloric effect (MCE) data in the paramagnetic regime indicates the role of applied magnetic field in suppressing the spin fluctuations. The interesting observation in this compound is that the presence of spin fluctuation smears out the MCE peak at the transition temperature and drags it to higher temperatures as a broad peak.

Magnetic phase inhomogeneity in frustrated intermetallic compound Sm2Ni0.87Si2.87

A new ternary compound Sm2Ni0.87Si2.87, belonging to intermetallic R2TX3 family (R = rare-earth, T = transition metals, X = Si, Ge, etc.), could be synthesized in single phase only by the deliberate introduction of lattice vacancies in the Ni and Si sites. The detailed studies of heat capacity as well as dc and ac magnetization including different non-equilibrium dynamical behaviour, viz., aging effect, temperature and field dependent magnetic relaxation and magnetic memory effect establish the compound to be a cluster-glass material having a spin freezing temperature ∼6.6 K. To understand the nature of the glassy phase, experimental results have been analysed using a few different theoretical models and found that the observed magnetic memory effect favours the hierarchical model over the droplet model. Competing exchange interaction driven magnetic phase inhomogeneity could be further confirmed through exchange bias effect. The observed magnetic phase inhomogeneity has been attributed to random magnetic anisotropy that develops due to local environmental variations between the rare-earth ions.

Chemical disorder driven reentrant spin cluster glass state formation and associated magnetocaloric properties of Nd2Ni0.94Si2.94.

In this work, we report the synthesis of a new ternary intermetallic compound, Nd2Ni0.94Si2.94, that forms in single phase only in a defect crystal structure. The compound exhibits an antiferromagnetic transition below 7.2 K (TN) followed by a spin cluster freezing behaviour below 2.85 K (Tf), which makes the compound a reentrant spin cluster glass system. The detailed studies of dc and ac magnetization, heat capacity, non-equilibrium dynamical behaviour, viz., aging effect, temperature and field dependent magnetic relaxation and magnetic memory effect establish the compound to be a cluster-glass material below freezing temperature. The interplay between competing exchange coupling (c/a ≃ 1.04 ⇒ JNN ≃ JNNN) and chemical disorder driven variation in the electronic environment among the Nd ions has been argued to be responsible for such a metastable state formation. A considerable value of MCE parameters (-ΔS ∼ 11.4 J kg-1 K-1, RCP ∼ 160 J kg-1 and ΔTad ∼ 5.2 K for a field change of 70 kOe) is obtained for this magnetically frustrated glassy compound.

Differences in Spatial Memory Recognition Due to Cognitive Style.

Field independence refers to the ability to perceive details from the surrounding context as a whole and to represent the environment by relying on an internal reference frame. Conversely, field dependence individuals tend to focus their attention on single environmental features analysing them individually. This cognitive style affects several visuo-spatial abilities including spatial memory. This study assesses both the effect of field independence and field dependence on performance displayed on virtual environments of different complexity. Forty young healthy individuals took part in this study. Participants performed the Embedded Figures Test for field independence or dependence assessment and a new spatial memory recognition test. The spatial memory recognition test demanded to memorize a green box location in a virtual room picture. Thereafter, during ten trials participants had to decide if a green box was located in the same position as in the sample picture. Five of the pictures were correct. The information available in the virtual room was manipulated. Hence, two different experimental conditions were tested: a virtual room containing all landmarks and a virtual room with only two cues. Accuracy and reaction time were registered. Analyses demonstrated that higher field independent individuals were related to better spatial memory performance in two landmarks condition and were faster in all landmark condition. In addition, men and women did not differ in their performance. These results suggested that cognitive style affects spatial memory performance and this phenomenon is modulated by environment complexity. This does not affect accuracy but time spent. Moreover, field dependent individuals are unable to organize the navigational field by relying on internal reference frames when few landmarks are available, and this causes them to commit more errors.

Cooling field dependent exchange bias in Mn2Ni1.4Ga0.6: A reentrant spin glass system with short range ferromagnetic ordering

The intermetallic alloy, Mn2Ni1.4Ga0.6, has been investigated by x-ray diffraction, dc magnetization, and ac susceptibility measurements. The material exhibits a non-modulated tetragonal structure, and undergoes a ferromagnetic transition near room temperature. Ac susceptibility and dc magnetization measurements show that below the Curie temperature, short range ferromagnetic ordering and reentrant spin glass state coexist in the material. A cooling field dependent exchange bias effect, with a maximum exchange bias field of 730 Oe, for a cooling field of 1 kOe, has also been observed in the material. The experimental observations suggest that the exchange bias effect in Mn2Ni1.4Ga0.6 is a result of the interaction between the coexisting spin glass and short range ferromagnetic ordering in the material.

Bose glass behavior in(Yb1−xLux)4As3representing randomly diluted quantum spin-12chains

The site-diluted compound (Yb$_{1-x}$Lu$_x$)$_4$As$_3$ is a scarce realization of the linear Heisenberg antiferromagnet partitioned into finite-size segments and is an ideal model compound for studying field-dependent effects of quenched disorder in the one-dimensional antiferromagnets. It differentiates from the systems studied so far in two aspects - the type of randomness and the nature of the energy gap in the pure sample. We have measured the specific heat of single-crystal (Yb$_{1-x}$Lu$_x$)$_4$As$_3$ in magnetic fields up to 19.5 T. The contribution $C_{\perp}$ arising from the magnetic subsystem in an applied magnetic field perpendicular to the chains is determined. Compared to pure Yb$_4$As$_3$, for which $C_{\perp}$ indicates a gap opening, for diluted systems a non-exponential decay is found at low temperatures which is consistent with the thermodynamic scaling of the specific heat established for a Bose-glass phase.