Miracle-dz/UniFAR-FTUs huggingface dataset:
Phonon thermal conductivity of monolayer MoS2 sheet and nanoribbons

We investigated the thermal conduction of monolayer MoS2 sheet and nanoribbons using molecular dynamics simulations. Room temperature thermal conductivity of monolayer MoS2 is found to be 1.35 W/mK, which is three orders of magnitude lower than that of graphene. In contrast to the remarkable size effect observed in graphene nanoribbons, the thermal conductivity of MoS2 nanoribbons is insensitive to width (3–16 nm), length (4–111 nm), and the type of edge, which are explained by the local heat flux analysis and phonon scattering mechanisms. The low thermal conductivity together with reported high Seebeck coefficient opens up the possibility to realize MoS2-based two-dimensional thermoelectric devices.
Effects of Diabatic Heating and Cooling in the Rapid Filamentation Zone on Structure and Intensity of a Simulated Tropical Cyclone

AbstractThe effects of diabatic heating and cooling in the rapid filamentation zone (RFZ), within which inner rainbands are often active, on tropical cyclone (TC) structure and intensity are investigated based on idealized numerical experiments using a cloud-resolving TC model (TCM4). The results show that removal of heating (cooling) in the RFZ would reduce (increase) the TC intensity. Diabatic heating in the RFZ plays an important role in increasing the inner-core size whereas diabatic cooling tends to limit the inner-core size increase or even reduce the inner-core size of a TC. Removal of both diabatic heating and cooling in the RFZ greatly suppresses the activity of inner rainbands but leads to the quasi-periodic development of a convective ring immediately outside of the inner core. A similar convective ring also develops in an experiment with the removal of diabatic heating only in the RFZ. With diabatic cooling removed only in the RFZ, an annular-hurricane-like structure arises with the outer rain.
The spread of (mis)information: A social media experiment in Pakistan

This randomized experiment on a social media platform in Pakistan measures the impact of two treatments that fully control access to misinformation relative to a more standard ex-post approach to controlling misinformation. In the ﬁrst treatment, no misinformation was allowed on the platform, while in the second, it was allowed with an o ﬃ cial rebuttal. The experiment focuses on misinformation regarding COVID-19 and is combined with an intervention to disseminate o ﬃ cial information about the pandemic on the platform. Controlling misinformation through either treatment reduces platform usage. It also reduces exposure to o ﬃ cial information by more than it reduces exposure to misinformation.
Localized Representation of Formative Assessment in China: A Regional Study from a Sociocultural Perspective

Formative assessment originated and developed in a Western context. With its function of learning improvement being evidenced in research, formative assessment has been adopted in assessment initiatives in multiple contexts including that of China. Research, however, reveals that formative assessment as implemented in Chinese contexts is by no means equivalent to what is understood and implemented in the West; rather, in many cases, it is decontextualised and recontextualised, or culturally appropriated. This paper presents findings of a study which examined the culturally appropriated representation of formative assessment within eight universities in a mid-western province of China. Senior administrators in each university were interviewed face-to-face and individually to fulfill three purposes: (1) To clarify understandings of formative assessment in the area of college English education; (2) To explore the existing gap between formative assessment principles and their representation in College English Curriculum Requirements (CECR), and the gap between formative assessment initiatives at the national level and local contexts; and (3) To distill implications for policy-borrowing and effective implementation in the Chinese context.
Observation of ferromagnetism at room temperature in ZnO thin films

Room-temperature ferromagnetism (FM) has been observed in laser-ablated ZnO thin films. The FM in this type of compound does not stem from oxygen vacancies as in the case of TiO2 and HfO2 films, but from defects on Zn sites. Magnetization of very thin films is much larger than that of the thicker films, showing that defects must be located mostly at the surface and/or the interface between the film and the substrate. Results on Fe-doped ZnO and Mn-doped ZnO films reveal clearly that the metal-transition doping does not play any essential role in introducing the magnetism in ZnO.
High resolution numerical studies of separatrix splitting due to non-axisymmetric perturbation in DIII-D

In DIII-D the splitting and deformation of the separatrix due to externally applied resonant magnetic perturbations is calculated using a vacuum field line integration code (TRIP3D–MAFOT). The resulting footprint pattern on the divertor target plates is shown in high resolution by contour plots of the connection lengths and penetration depths of the magnetic field lines. Substructures inside the divertor footprint stripes are discovered. Regions of deep penetrating long connecting field lines, which are related to the internal resonances by their manifolds, alternate with regions of regular short connecting field lines. The latter are identified as compact laminar flux tubes, which perforate the perturbed plasma region close to the x-point. The properties and consequences of such flux tubes are investigated in detail. The interaction of different resonant magnetic perturbations is analysed considering the separatrix manifolds. Constructive and destructive interference of the manifolds is discovered and studied.
The Mount Wilson Observatory Metallicity Index, C RV: Comparison with Other Photometric Systems

A new spectrophotometric index, C RV , is assessed as a metallicity indicator for late-type stars. The index is the ratio of the measured photospheric fluxes in 20 A wide passbands centered at 4001 and 3901 A. C RV correlates directly with the metallicity index, m 1 , of the Stromgren uvby system and with the metallicity index hk, of Anthony-Twarog et al. (1991). Using observations of 236 dwarfs and 140 giants combined with stellar atmosphere models (Kurucz 1991), we compared the sensitivity of the C RV , m 1 , and hk indices to metal abundance. We also studied the sensitivity of the C RV , c 1 , and hk indices to surface gravity
Asymptotic Theory of Overparameterized Structural Models

Abstract A theory of overparameterized structural models is presented. In such a model some “redundant” parameters are involved; the parameter vector is not identified, and the information matrix is not nonsingular. The minimum discrepancy function (MDF) test statistic is shown to have an asymptotic chi-squared distribution almost everywhere for a wide class of discrepancy functions. Asymptotic distribution properties of the MDF estimators are investigated. The factor analysis model is discussed as an example.
Electronic structure of FeS 2 : The crucial role of electron-lattice interaction

Using the results of fully self-consistent all-electron first-principles calculations for semiconducting iron pyrite we discuss the major factors governing the semiconducting properties as well as the chemical bonding of this material. The calculations are based on density functional theory within the local density approximation and employ the augmented spherical wave method in its scalar-relativistic implementation. The electronic properties are dominated by strongly hybridized Fe $3d$ and S $3p$ states. The chemical bonding is analyzed using an ab initio implementation of the crystal orbital overlap population. Chemical stability is shown to result mainly from the Fe-S bonding. While the upper part of the valence band is formed mainly from Fe ${3dt}_{2g}$-derived states the conduction band comprises the ${e}_{g}$-derived levels. The conduction band minimum, in contrast, is exclusively due to S $3p$ states, this fact explaining the observed high optical absorption. For the same reason the optical properties are strongly influenced by the short sulfur-sulfur bonds. We demonstrate that only small deviations in the sulfur pair bond lengths involve rather drastic changes of the near-gap electronic states which might even turn the indirect band gap into a direct one. These findings allow us to understand the rather high sensitivity of the optical band gap to the incorporation of defects. Finally, our results open perspectives for photovoltaic applications of ${\mathrm{FeS}}_{2}$.
Assessment of Experimental and Computational Transonic Base Pressure Using Flight Data

The transonic base pressure distributions on a winged reentry vehicle configuration derived from wind-tunnel tests and computational fluid dynamics analyses are compared with flight data from the High Speed Flight Demonstration Phase II test. Results show that wind-tunnel forebody axial-force data agree well with the flight test data, but the base pressures differ. For a wind-tunnel model supported by a straight sting, base pressure correction using ventral model support data was found to be effective when the model was located far upstream of the roll pod. The base pressure obtained by computational fluid dynamics depends greatly on the number of grid points used in the base flow region, and it is shown that dense grids are able to reproduce the effect of the existence of the support sting despite the use of a classical turbulence model.
Dayside pickup oxygen ion precipitation at Venus and Mars: Spatial distributions, energy deposition and consequences

The fluxes and energy spectra of picked-up planetary O+ ions incident on the dayside atmospheres of Venus and Mars are calculated using the neutral exosphere models of Nagy and Cravens (1988) and the Spreiter and Stahara (1980) gasdynamic model of the magnetosheath electric and magnetic field. Cold (∼10 eV) O+ ions are launched from hemispherical grids of starting points covering the daysides of the planets and their trajectories are followed until they either impact the dayside “obstacle” or cross the terminator plane. The impacting, or precipitating, ion fluxes are weighted according to the altitude of the hemispherical starting point grid in a manner consistent with the exosphere density models and the local photoion production rate. Maps of precipitating ion number flux and energy flux show the asymmetrical distribution of dayside energy deposition expected from this source which is unique to the weakly magnetized planets. Although the associated heating of the atmosphere and ionosphere is found to be negligible compared to that from the usual sources, backscattered or sputtered neutral oxygen atoms are produced at energies exceeding that needed for escape from the gravitational fields of both planets. These neutral “winds,” driven by pickup ion precipitation, represent a possibly significant loss of atmospheric constituents over the age of the solar system.
The Effect of Human Resource Management Practices on the Quality of Service, Customer Satisfaction, and Organizational Performance in Cypriot Urban Hotel Industry

The article examines the effects of Human Resource Management (HRM) practices on the quality of service, customer satisfaction, and organizational performance in the urban hotel industry. The data was gathered through a survey of urban hotels in Cyprus. Quantitative method was used in order to collect necessary data from human resource managers, employees, and consumers from each urban hotel under study. Specifically, the researchers used questionnaires. According to the research findings, HRM practices have a significant impact on customer satisfaction. The strongest association was found between organizational performance and customer satisfaction, which is a significant finding because it is proven for the first time in a study related to the Cypriot urban hotel industry. HRM practices and service quality practices both have an impact on customer satisfaction. Finally, this study supports the close relationship between HRM practices and hotel performance. The research findings reveal that the HRM practices have an extremely effect on customer satisfaction. The strongest correlation was between organizational performance and customer satisfaction, which an outcome of a major importance since it is confirmed for the first time in a study connected with Cypriot urban hotel industry. HRM practices as well as service quality practices reveal their consequences on customers satisfaction. Finally, this research confirms the strong connection between HRM practices and Hotel Performance.
Nucleation and growth of single crystals with uniform crystallographic orientation inside alumina nanopores

Single crystal rods, having nanometer-size diameter, were grown with uniform crystallographic orientation inside a matrix of alumina nanopores. The fabrication process of this nanocomposite structure consists of several stages. First, a highly dense array of alumina pores (about 1011cm−2 and an average diameter of about 35nm) is prepared by an electrochemical anodization process of pure Al substrate. Then, the pores are filled with a liquid solution aided by the pores’ capillary forces. Finally, the temperature of the liquid solution is slightly decreased to a supersaturated state where precipitation starts only at the pore bottom. The nucleation preference at the pore bottom is explained thermodynamically based on the contact angle, geometrical parameters of the nucleus, surface curvature, and pore diameter. In each pore the nucleus is grown to a single crystal that completely fills its volume. The crystallographic orientation of the single crystals inside the pores can be controlled by temperature and c.
Substrate-induced phases: transition from a liquid-crystalline to a plastic crystalline phase via nucleation initiated by the substrate

The presence of substrate-induced phases in thin films is an intriguing phenomenon with the physical and chemical factors responsible for their formation are not yet clearly understood. In this article, we present the structure and morphological changes associated with a substrate-induced phase in a discotic liquid crystal. The thin films of the discotic molecule are characterised by a combination of various X-ray diffraction methods to investigate the structural properties. Atomic force microscopy and polarised optical microscopy are used to determine the thin film morphologies. This is the first experimental proof of the presence of a substrate-induced phase in discotic liquid crystal, although they are known in thin films of molecular crystals. Moreover, we sought to decipher how the substrate-induced phase behaves with the evolution of time, temperature and changes at the interfaces. This work gives a unique example where the two-dimensional liquid-crystalline phase converts to a three-dimensional crystal plastic phase because of nucleation caused by the solid substrate over a time scale of a month or longer.
An algorithm for inferring the two‐dimensional structure of the nighttime ionosphere from radiative recombination measurements

We present a technique for retrieving the two‐dimensional structure of the ionosphere using the measured variations of ultraviolet emissions produced by radiative recombination at 911 and 1356 Å as measured by satellite‐based limb scanning instruments. The algorithm uses an iterative scheme based on discrete inverse theory to determine the best fit to the data. We present the results of a simulation that demonstrates the algorithm's performance for an inversion covering the nighttime half of the orbit. The algorithm was tested using “data” generated with the international reference ionosphere (IRI‐90; Bilitza [1990]). The algorithm accurately retrieved the nighttime F region electron density.
Ueber die Integration logarithmisch-rationaler Differentiale.

Bekanntlich reduciren sich viele Aufgaben der Geometrie und Physik zuletzt auf die Auflösung von Gleichungen, welche in den schwierigeren Fällen sowohl die unbekannten Gröfsen als deren Ableitungen (Differential Coefficienten) enthalten können. Zuweilen lassen sich in sol.chen Gleichungen entweder die veränderlichen Gröfsen absondern, oder es lassen sich wenigstens Ausdrücke für die unbekannten Grö'fsen mit Hülfe bestimmter Integrale (integrales definies) finden. In beiden Fällen beruhet zuletzt die Auflösung auf Integrationen nach E ine r Veränderlichen, wie fdx.fx, welche im Allgemeinen Q u a d r a t u r e n heifsen, und welche also für beliebige Functionen wie fx verlangt werden. Die Mathematik löset im Allgemeinen ihre Aufgaben durch vorausgerechnete Tafeln, in welchen für jeden Werth der willkürlich veränderlichen Gröfsen die zugehörigen Werthe der Functionen gefunden werden. ' Solche Tafeln sind also im Allgemeinen für jede Function, die in den Elementen des Calculs vorkommt, nothwendig. Wenn z. B. das Product zweier Zahlen verlangt wird, so findet man dasselbe in der Producten Tafel, oder dem sogenannten Einmaleins. Ob die Tabelle niedergeschrieben sei, oder ob der Rechner sie im Gedächtnifs habe, ist offenbar gleichgültig.
A New Derivation of the Extinction-to-CO Column Density Ratio in the Chamaeleon I Dark Cloud

We have analyzed new datasets of 13CO (J = 1-0) and C 18 0 (J = 1-0) emission obtained with NANTEN and visual extinction, Ay, derived from DENIS J-band observations in the Chamaeleon I dark cloud. The column densities of both molecular isotopes, 7V(13CO) and iV(C180), have been derived as­ suming LTE. Both 7V(13CO) and 7V(C180) are linearly correlated with Ay in the range Ay < 10 mag. We established the relationships iV(13CO)(cm-2) = (1.2 ± 0.1) x 10 15Av(mag) + (0.7 ± 0.3) x 10 15 and 7V(C180)(cmT2) - (3.5 ± 0.3) x 10 14Av(mag) - (5.7 ± 1.3) x 10 14. In a region of clustered T Tauri stars, however, both the Ay-N(13CO) and Ay-N(ClsO) relationships are by a factor of ~ 2 steeper than the above. This may be mainly due to underestimate s of the Ay values, and the J-band star count might deserve a more careful examination for possible underestimates of associated young stars. Compared with the relationships for the other clouds, the slope of the Ay-N(13CO) relationship is relatively shallower and that of the Ay-N(ClsO) relationship in a non-cluster forming region is slightly steeper. These facts suggest that cloud-to-cloud variation is significant in the Ay-N(CO) relationships.
Dislocations and stacking faults in hexagonal GaN

We present experimental and theoretical results on extended defects of hexagonal GaN grown by metal organic vapour deposition (MOCVD). Transmission electron microscopy (TEM) measurements indicate the presence of 3 nm wide type I1 stacking faults (SFs) related to the MOCVD growth, and 2–4 nm SFs of unidentified type related to the ion implantation. We simulated infinite SFs of different types I1, I2 and I3. First principles calculations were used to model Shockley partial dislocations, the core structure of the dislocations and intrinsic SFs. We estimate defect level positions and the formation energy of the infinite SFs. We also present results of the calculations and available experimental data on finite size SFs bounded by partial dislocations in wurtzite GaN. Calculation of the infinite SFs revealed shallow levels, but no deep levels. In the SFs bound by dislocations there are deep filled levels in the range of 0.4–0.8 eV from the valence band maximum (VBM) located at the atoms of the 90° dislocations. We also calculated the segregation of the C, n‐dopant, Si or O and the p‐dopant, Mg, to the dislocations and SFs. The effect of the segregation is found to be stronger for the SFs with partials. The results of the calculations are correlated with the experimental data on GaN obtained from high resolution TEM and Hall measurements. We suggest mechanisms of the formation of the SFs I1 and I2 after ion implantation and high temperature anneal and explain the difficulties of p‐type doping with the formation of the extended defects.
FAR-ULTRAVIOLET SPECTRAL IMAGES OF THE ORION–ERIDANUS SUPERBUBBLE REGION

The far-ultraviolet (FUV) continuum and spectral images of C iv and H2 emission lines for the region of the Orion–Eridanus Superbubble are hereby presented and compared with maps obtained in other wavelengths. While the region shows complex structures, consisting of hot gases and cold dust, a close examination reveals that the FUV emission in this region can be understood reasonably as the result of their interactions. We confirm the origin of most diffuse FUV continuum to be starlight scattered by dust, but we also find that ionized gas contributes 50%–70% of the total FUV intensity in the regions of Hα arcs. We note the bright diffuse FUV continuum in the eastern part of the northern region, which has a lot of dust, and attribute it to a greater abundance of bright, early-type stars in this region than in the west, as the amount of dust itself does not seem to be much different across “arc A,” which separates the two regions. In addition, two P Cygni-type stars are identified in this eastern region and their peculiar spectral profiles around the C iv emission line are manifested in the scattered diffuse spectrum. Besides this, the C iv emission is generally enhanced at the boundaries of the hot X-ray cavities where thin dust regions are located, confirming the thermal interface nature of the origin of this cooling emission line. The morphology of the H2 emission shows a general correlation with dust extinction features but its intensity peaks are located in thin dust areas, rather than the peak dust regions. Furthermore, H2 emission is weak in the arc A region even though the arc passes through the center of the dust-rich area. Hence, the H2 emission and dust features, together with those of X-ray and ion line emissions, show the stratified structure of arc A quite well, again confirming its thermal interface nature.
Effect of seepage on scour due to submerged jets and resulting flow field

Experiments were conducted to investigate the effect of upward seepage on the characteristics of scour hole due to horizontal submerged jets and the resulting flow field within the scour hole. In the experiments, the submerged jets had a range of submergence factors from 3.22 to 26.5 and jet Froude numbers from 0.82 to 1.48 over beds of sediments (median sizes = 0.8 mm, 1.86mm and 3 mm) downstream of a sluice gate under different upward seepage velocities. The characteristic lengths of the scour hole determined from the equilibrium scour profiles are: The maximum equilibrium scour depth, the horizontal distance of maximum scour depth from the sluice gate, the horizontal extension of scour hole from the sluice gate, the dune height and the horizontal distance of dune crest from the sluice gate. The experimental results show that all the characteristic lengths decrease with increase in seepage velocity, as a result of jet deflection by the upward seepage velocity. Using the experimental data, the time-variation of scour depth is scaled by an exponential law, where the time scale decreases linearly with increase in the ratio of seepage velocity to issuing jet velocity. The flow field within scour hole under different upward seepage velocities was detected by the acoustic Doppler velocimeter. Vector plots of the flow field show that the decay rate of submerged jet increases with increase in seepage velocity. The vertical profiles of turbulent kinetic energy and Reynolds stress at different streamwise distances and the horizontal distributions of bed shear stress acting on the scoured beds are plotted for different (with and without) upward seepage velocities.