Miracle-dz/UniFAR-FTUs huggingface dataset:
Invariant theory, tensors and group characters

In Part I is developed the theory of the tensor as a device for the construction of concomitants. This part includes the specific separation of a complete cogredient tensor of rank r into simple tensors, with a formula indicating the corresponding separation of a mixed tensor; also the corresponding theory in tensors to the Glebsch theory of algebraic forms, and a compact proof of the fundamental theorem that all concomitants under the full linear group can be obtained by the multiplication and contraction of tensors. The general equivalence is demonstrated, so far as elementary applications are concerned, of the method of tensors with the classical symbolic method of invariant theory. The first part forms a foundation for the principal theory of the paper which is developed in Part II. This primarily consists of an analysis of the properties of S-functions which provides methods for predicting the exact number of linearly independent concomitants of each type, of a given set of ground forms. Complementary to this, a method of substitutional analysis based on the tableaux which must be constructed in obtaining a product of S-functions, enables the specific concomitants of each type to be written down. Part III consists of applications to the classical problems of invariant theory. For ternary perpetuants a generating function is obtained which is not only simpler than that given by Young, but is also more general, in so far as it indicates, as well as the covariants, also the mixed concomitants. Extension is made to any number of variables. The complete sets of concomitants, up to degree 5 or 6 m the coefficients, are obtained for the cubic, quartic and quadratic complex in any number of variables. Alternating concomitant types are described and enumerated. A theorem of conjugates is proved which associates the concomitants of one ground form with the concomitants of a ground form of a different type, namely, that which corresponds to the conjugate partition. Some indication is made of the extension of this theory to invariants under restricted groups of transformations, e.g. the orthogonal group, but the full development of this extended theory is to be the subject of another paper.
Classical Spin Models

Classical spin models bridge the gap between a full electronic description of a magnetic material and conventional micromagnetism, where magnetic properties are calculated on the basis of a continuum theory for the energy of the system under consideration. Since spin models take into account magnetic configurations on an atomic level, they make it possible to investigate ferromagnets as well as antiferromagnets or even heterostructures composed of both of them. While well-established methods exist for the calculation of thermal equilibrium properties, the investigation of thermally activated spin dynamics is a newer field of research which is currently developing. One goal of this review is to give an overview on numerical approaches related to classical spin systems, where the most established methods are either a numerical solution of the Landau–Lifshitz–Gilbert equation with Langevin dynamics or Monte Carlo simulations. Special emphasis is laid on the relation between these two methods and on the possibility to quantify the steps of a Monte Carlo procedure in terms of realistic time intervals. Furthermore, as typical applications of these numerical techniques, this overview includes a description of thermally activated magnetization switching in cylindrical geometries as well as an introduction to the simulation of exchange bias. Keywords: spin models; stochastic Landau–Lifshitz–Gilbert equation; Monte Carlo simulation; magnetization switching; exchange bias
Thermally mediated droplet formation in microchannels

Precise dispensing of microdroplets is an important process for droplet-based microfluidics. The dropletformation by shear force between two immiscible fluids depends on their flow rates, the viscosities, and the interfacial tension. In this letter, the authors report the use of integrated microheater and temperature sensor for controlling the dropletformation process. The technique exploits the dependency on temperature of viscosities and interfacial tension. Using a relatively low heating temperature ranging from 25 to 70 ° C , the droplet diameter can be adjusted to over two times of its original value. The relatively low temperature range makes sure that this concept is applicable for droplets containing biological samples.
Dense Z-pinch plasma as a dynamical percolating network : From laboratory plasmas to a magnetoplasma universe

The results of a high-resolution processing, based on techniques of fractal dimension analysis, of experimental data from earlier experiments on the linear Z-pinches are presented, which prove the electric current-carrying plasmas to be a random fractal medium. The basic building block of this medium is identified to be an almost-closed helical filamentary magnetoplasma configuration (we call it heteromac). The heteromacs are coupled together through long-range self-sustained filamentation and, thus, form a dynamical percolating network with dissipation. The results (i) extend recently identified phenomenon of the 3D large-scale (up to several centimeter size) helical filamentary plasma structures (Kukushkin et al. 1994, 1995, 1997a) in plasma focus gaseous discharges to the case of Z-pinch gaseous discharges and (ii) provide a novel view into the dynamics of Z-pinch's necks, plasma spikes, and magnetic bubbles as well as into generic features of electric current-carrying plasmas varying from low-electric current laboratory plasmas to cosmic plasmas. This covers about 30 orders of magnitude of length scale and suggests unprecedented opportunities for interpolating between and extrapolating from well-understood phenomena. A magnetoplasma universe model is suggested.
The environment and physics of the early solar system

Astronomical observations and modelling suggest that stars assemble out of the gas and dust collected in the cores of vast clouds in interstellar space. These cores gravitationally attract more material from the surrounding cloud, until enough mass is concentrated to trigger their gravitational collapse. The result of this process is a growing object (a protostar), slowly fed by a flattened disc of material (aprotostellar disc) that encircles it. These discs are the analogues of the early solar system, and potential sites of current planet formation. Provided that disc material can shed its excess angular momentum, matter will flow onto the central object, and it is believed that this is how stars typically gain most of their mass. Although this basic paradigm appears solid, many aspects of this process remain unexplained. The mechanisms responsible for this transport of angular momentum are not well understood. The most promising are turbulent motions driven by the magnetorotational instability, and large-scale outflows accelerated from the disc surfaces. Both processes are driven by magnetic fields and are, in turn, likely to strongly affect the structure, evolution and planet-forming processes in the disc. The low ionisation of the material, however, may prevent the magnetic field from driving these processes in some regions of the disc. On the other hand, a record of the formation process of our own solar system is preserved in primitive meteorites, the ‘building blocks’ of the solar nebula. Preserved in the samples are a variety of objects that have experienced very high temperatures (∼1700–2000 K), evidence that could imply a hot ambient temperature in the solar nebula. In contrast, the preservation of presolar grains in meteorites, geochemical evidence for a poorly mixed nebula, and astrophysical observations of forming stars suggest a cool protoplanetary disc, where temperatures are too low to produce this thermal processing. The coexistence of hot and cold material in the early solar system has remained unexplained for many decades. Magnetic fields, again, may hold the key to solve this longstanding puzzle in planetary science. In this review I first examine the meteoritic record and key properties of protostellar discs. I then discuss the nature and viability of the processes thought to enable accretion in these systems, focussing on the dependence of these processes on the disc environmental conditions. The implications for planet formation are also discussed.
Robustifying Multivariate Trend Tests to Nonstationary Volatility

This article studies inference of multivariate trend model when the volatility process is nonstationary. Within a quite general framework we analyze four classes of tests based on least squares estimation, one of which is robust to both weak serial correlation and nonstationary volatility. The existing multivariate trend tests, which either use non-robust standard errors or rely on non-standard distribution theory, are generally non-pivotal involving the unknown time-varying volatility function in the limit. Two-step residual-based i.i. d. bootstrap and wild bootstrap procedures are proposed for the robust tests and are shown to be asymptotically valid. Simulations demonstrate the effects of nonstationary volatility on the trend tests and the good behavior of the robust tests in finite samples.
Calculation of Transonic Aileron Buzz

An implicit finite-difference computer code that uses a two-layer algebraic eddy viscosity moc*°* <*nd evart geometric specification of the airfoil has been used to simulate transonic aileron buzz. The calculated results, which were performed on the Illiac IV parallel computer processor and the Control Data 7600 computer, are in essential agreement with the original expository wind-tunnel data taken in the Ames 16-ft wind tunnel just after World War II. These results and a description of the pertinent numerical techniques are included. N a previous publication,1 a general viscous airfoil computer code that uses an implicit finite-difference scheme was described. By comparison to available numerical and experimental data, the computer code was shown to be accurate for various inviscid and viscous, steady and unsteady transonic flows about airfoils. The computer program employs general coordinate transformations that allow arbitrary body shape and motion. The purpose of this paper is twofold: 1) to further demonstrate the numerical technique and 2) to further investigate unsteady flow phenomena about airfoils. To these ends, the calculation of aileron buzz phenomena was undertaken using the Control Data Corporation 7600 computer and the Illiac IV parallel processor computer. The latter machine is more economical for extensive viscous flowfield calculations than the Control Data machine. The problem of transonic aileron buzz was apparently first encountered by pilots in World War II. Because later flight tests of the P-80 (i.e., F-80) proved hazardous,2 Erickson and Stephenson3 undertook wind tunnel tests of a P-80 half-span wing mounted in the Ames 16-ft wind tunnel. From these experiments, Erickson and Stephenson concluded that aileron buzz is a one-degree-of-freedom flutter in which shock-wave motion causes a phase shift in the response of the hinge moment to the aileron movement. Oscillatory aileron motion was observed for various combinations of Mach number, geometry, and mechanical damping. Although aileron buzz is no longer as serious a problem because of the introduction of hydraulically actuated controls, we can now use modern numerical techniques to explore questions still unanswered by experiment and simplified theory.4 In this paper then, we begin to investigate the aileron buzz problem using numerical techniques. In Sec. II, the governing flowfield equations are briefly sketched. The numerical method, with extensions over Ref. 1, and the boundary and grid treatment of the moving aileron are reviewed in Sec. III. Finally, numerical results are discussed in Sec. IV and compared to the data of Ref. 3.
A Theory of Gross and Net Capital Flows Over the Global Financial Cycle

We develop a theory to account for changes in gross and net capital flows over the global financial cycle (GFC). The theory relies critically on portfolio heterogeneity among investors within and across countries, related to risky portfolio shares and portfolio shares allocated to foreign assets. A global drop in risky asset prices during a downturn of the GFC changes relative wealth within and across countries due to portfolio heterogeneity. This leads to changes in gross and net capital flows that are consistent with the stylized facts: all countries experience a decline in gross capital flows (retrenchment), while countries that have a net debt of safe assets experience a rise in total net outflows and net outflows of safe assets and a drop in net outflows of risky assets. The model is applied to 20 advanced countries and calibrated to micro data related to within country portfolio heterogeneity, as well as cross country heterogeneity of net foreign asset positions of safe and risky assets. The implications of the calibrated model for gross and net capital flows are quantitatively consistent with the data.
Social anxiety and depression symptoms in Chinese left-behind children after the lifting of COVID-19 lockdown: A network analysis

Background: Returning to social life after the lifting of COVID-19 lockdown may increase risk of social anxiety, which is highly co-morbid with depression. However, few studies have reported the association between them. Aims: To explore the complex relationship between social anxiety and depression symptoms in left-behind children after the lifting of the COVID-19 lockdown. Methods: A cross-sectional survey was conducted 6 months after the lockdown removal. A total of 3,107 left-behind children completed the survey with a mean age of 13.33 and a response rate of 87.77%. Depression and social anxiety severity were assessed by the DSM-5 Patient Health Questionnaire for Adolescents and the DSM-5 Social Anxiety Disorder Questionnaire, respectively. The symptom-level association between the two disorders was examined using network analysis. Results: After the lifting of COVID-19 lockdown, the prevalence of depression and social anxiety in left-behind children was 19.57% and 12.36%, respectively, with a co-morbidity rate of 8.98%. Network analysis showed that “Social tension” and “Social avoidance” had the greatest expected influence; “Humiliation” and “Motor” were bridge symptom nodes in the network. The directed acyclic graph indicated that “Social fright” was at the upstream of all symptoms. Conclusion: Attention should be paid to social anxiety symptoms in left-behind children after the lifting of COVID-19 lockdown. Prevention and intervention measures should be taken promptly to reduce the comorbidity of social anxiety and depression symptoms in the left-behind children after the lifting of lockdown.
Direct imaging of quantum antidots in MgO dispersed with Au nanoclusters

Formation of quantum antidots at the immediate neighborhood of Au nanocluster has been proposed in order to explain the observed nonlinear optical behavior of magnesium oxide (MgO) when Au nanoclusters were dispersed in it. In this letter, using high-angle annular dark-field imaging in an aberration-corrected scanning transmission electron microscope, we report the direct observation of clustering of vacancies in excess of Au atoms to form quantum antidots at the immediate neighborhood of the Au clusters, leading to a spatially associated Au nanoclusters and the quantum antidots. The antidots show a terraced layer structure and are typically faceted along the MgO{100} planes.
Measuring adherence to inhaled control medication in patients with asthma: Comparison among an asthma app, patient self‐report and physician assessment

Abstract Background Previous studies have demonstrated the feasibility of using an asthma app to support medication management and adherence but failed to compare with other measures currently used in clinical practice. However, in a clinical setting, any additional adherence measurement must be evaluated in the context of both the patient and physician perspectives so that it can also help improve the process of shared decision making. Thus, we aimed to compare different measures of adherence to asthma control inhalers in clinical practice, namely through an app, patient self‐report and physician assessment. Methods This study is a secondary analysis of three prospective multicentre observational studies with patients (≥13 years old) with persistent asthma recruited from 61 primary and secondary care centres in Portugal. Patients were invited to use the InspirerMundi app and register their inhaled medication. Adherence was measured by the app as the number of doses taken divided by the number of doses scheduled each day and two time points were considered for analysis: 1‐week and 1‐month. At baseline, patients and physicians independently assessed adherence to asthma control inhalers during the previous week using a Visual Analogue Scale (VAS 0–100). Results A total of 193 patients (72% female; median [P25–P75] age 28 [19–41] years old) were included in the analysis. Adherence measured by the app was lower (1 week: 31 [0–71]%; 1 month: 18 [0–48]%) than patient self‐report (80 [60–95]) and physician assessment (82 [51–94]) (p < 0.001). A negligible non‐significant correlation was found between the app and subjective measurements (ρ 0.118–0.156, p > 0.05). There was a moderate correlation between patient self‐report and physician assessment (ρ = 0.596, p < 0.001). Conclusions Adherence measured by the app was lower than that reported by the patient or the physician. This was expected as objective measurements are commonly lower than subjective evaluations, which tend to overestimate adherence. Nevertheless, the low adherence measured by the app may also be influenced by the use of the app itself and this needs to be considered in future studies.
Employer branding and employee performance at KAI: employee retention' role as mediator

Today's job seekers prefer well-known companies, even though they're less likely to be accepted. The HR team must brand the company as an employer. Employer branding can be a company's image, values, and work culture. Employer branding has a greater impact on employee loyalty than non-emotional factors on employees. This study aims to explain 1) employer branding's impact on employee retention and performance, 2) employee retention's impact on employee performance, and 3) employer branding's impact on employee performance through employee retention as a mediator. 110 frontline workers from PT Kereta Api Indonesia (Persero) DAOP VII Madiun made up the research sample. The sampling was proportional random. Using SPSS and Sobel, this study uses descriptive and inferential analysis. Influence test results show that employer branding increases employee retention and performance, and employee retention increases employee performance. The results of path analysis and Sobel test of the mediator's role show that the direct effect of employer branding on employee retention after being controlled by employee retention as a mediator is not significant. Employee retention acts as a full mediator for employer branding's effect on employee performance, according to the mediator test. 2) Companies can improve employee performance by improving employee retention via career opportunities, awards, and employee relationships.
Wernicke Encephalopathy Presenting with Dysphagia: A Case Report and Systematic Literature Review

Wernicke encephalopathy (WE) is a well-known neurological condition caused by thiamine (vitamin B1) deficiency that occurs in both alcoholic and non-alcoholic populations. We aimed to report a case of a patient with WE who presented with dysphagia and dysphonia and later developed typical symptoms of thiamine deficiency and to conduct a systematic review of the literature on this rare presentation of WE. We searched two databases (PubMed and Scopus) and included publications up to November 2022. We found 12 cases of WE and dysphagia, aged between 12 and 81 years; swallowing problems presented at the onset in nine patients (including the current case report). Our findings suggest that thiamine deficiency should be suspected in patients with dysphagia of unknown cause, even in the absence of alcohol abuse. In contrast to most WE patients, the majority of patients included in this review presented with dysphagia at the onset of their disease, even in the absence of the classic triad of cognitive impairment, ataxia, and oculomotor abnormalities, indicating that there could be varying susceptibilities to clinical manifestations of thiamine deficiency in different brain regions.
Dynamics of flare-driven chromospheric condensations

A general model of chromospheric condensation dynamics is developed under the assumption of sudden impulsive-phase flare energy release. The basic equation of motion for the downward-moving condensation is derived from the momentum equation and from general features seen in numerical simulations. This equation is solved for a number of different cases. The 'lifetime' of condensation and the time for the velocity to drop to half its peak value are computed. The peak downflow speed is examined as a function of the flare energy flux, and comparisons are made between downflow speeds predicted by both thick-target 'explosive evaporation' and evaporation driven conductively. 43 refs.
Recent Progress on AlGaN Based Deep Ultraviolet Light-Emitting Diodes below 250 nm

AlGaN based deep ultraviolet (DUV) light-emitting diodes (LEDs), especially with a wavelength below 250 nm, have great application potential in the fields of sterilization and disinfection, gas sensing, and other aspects. However, with the decrease of emission wavelength, performance collapse occurs and the external quantum efficiencies (EQE) of sub-250 nm LEDs are usually below 1% for a long time. Low efficiencies are resulted from problem accumulation of all aspects, including n/p-type doping and contacts, carrier confinements and transports, light extraction, etc. To achieve high EQE of sub-250 nm LEDs, problems and solutions need to be discussed. In this paper, the research progress, development bottlenecks, and corresponding solutions of sub-250 nm LEDs are summarized and discussed in detail.
Detection of CO J = 2 goes to 1 emission from the polar rings of NGC 2685 and NGC 4650A

We report the detection of the J = 2 goes to 1 (230 GHz) line of carbon monoxide in the polar rings of the galaxies NGC 2685 and NGC 4650A, and we use the results in a simple analysis of the composition of the neutral interstellar medium therein. Only 17%-35% of the gas mass of the NGC 4650A ring is provided by molecular clouds, perhaps consistent with the conventional picture of the origin of polar rings in the capture of a dwarf galaxy or tidal mass transfer from a spiral galaxy. The polar ring of NGC 2685, however, is quite rich in molecular matter, with an H2 mass greater than the neutral atomic hydrogen mass. Such a composition may be difficult to explain with the picture that applies to NGC 4650A.
Characteristics of the persistent emission of SGR 1806-20

Earlier, using the X-ray satellite ASCA, we had identified the soft gamma-ray burst repeater (SGR) 1806-20 with a persistent X-ray source, AX 1805.7-2025 which is located close to the center of the radio supernova remnant G10.0-0.3. A burst seen by Burst and Transient Source Experiment (BATSE) was shown to be centered on G10.0-0.3. Here we report detailed temporal and spectral analysis of the persistent source. We find that AX 1805.7-2025 is a very compact source, size less than 30 sec in diameter, with a power-law spectrum. The count rate from AX 1805.7-2025 is steady on timescales of minutes, days, and 1 week. Most supernova remnants have extended X-ray emission ascribed to shocked gas. We set an upper limit to an extended X-ray emission both in continuum and line emission. We conclude that an isolated neutron star, most likely a pulsar, powers the radio remnant G10.0-0.3. Finally, we note that the persistent spectrum appears to be less absorbed than the burst spectrum.