Miracle-dz/UniFAR-FTUs huggingface dataset:
Accelerating Star Formation in Clusters and Associations

We use our own, recently developed pre-main-sequence evolutionary tracks to investigate the star formation histories of relatively nearby associations and clusters. We first employ published luminosities and effective temperatures to place the known members of each region in the H-R diagram. We then construct age histograms detailing that region's history. The groups studied include Taurus-Auriga, Lupus, Chamaeleon, ρ Ophiuchi, Upper Scorpius, IC 348, and NGC 2264. This study is the first to analyze a large number of star-forming regions with the same set of theoretical tracks. Our investigation corroborates and extends our previous results on the Orion Nebula Cluster. In all cases, we find that star formation began at a relatively low level some 107 yr in the past and has more recently undergone a steep acceleration. This acceleration, which lasts several million years, is usually continuing through the present epoch. The one clear exception is the OB association Upper Scorpius, where the formation rate climbed upward, peaked, and has now died off. Significantly, this is also the only region of our list that has been largely stripped of molecular gas. The acceleration represents a true physical phenomenon that cannot be explained away by incompleteness of the samples; nor is the pattern of stellar births significantly affected by observational errors or the presence of unresolved binaries. We speculate that increasing star formation activity arises from contraction of the parent cloud. Despite the short timescale for acceleration, the cloud is likely to evolve quasi-statically. Star formation itself appears to be a critical phenomenon, occurring only in locations exceeding some threshold density. The cloud's contraction must reverse itself, and the remnant gas dissipate, in less than 107 yr, even for aggregates containing no massive stars. In this case, molecular outflows from the stars themselves presumably accomplish the task, but the actual dispersal mechanism is still unclear.
PR ] 2 2 M ay 2 01 1 Conditional central limit theorem via martingale approximation Dedicated to the memory of

In this paper we survey and further study partial sums of a stationary process via approximation with a martingale with stationary differences. Such an approximation is useful for transferring from the martingale to the original process the conditional central limit theorem. We study both approximations in L1 and in L2. The results complement the work of Dedecker Merlevède and Volný (2007), Zhao and Woodroofe (2008), Gordin and Peligrad (2009). The method provides an unitary treatment of many limiting results for dependent random variables including classes of mixing sequences, additive functionals of Markov chains and linear processes.
Charge fluctuations and fractional charge of fermions in 1+1 dimensions

Charge fluctuations of solitons with arbitrary fractional fermion number in 1+1 dimensions are calculated, generalizing the result of Kivelson and Schrieffer for solitons with fermion number 1/2. The soliton charge is measured by a sampling function f(x) such that f(x)approx. =1 over a region of width L around the soliton and then falls to zero in a distance l. It is shown that vacuum fluctuations vanish as l/sup -1/ for large l while the additional fluctuations due to the presence of a soliton vanish as either exp(-L/xi) or exp(-2.delta./sub 0/L); xi is the soliton width and . delta. /sub 0/ is the mass gap of a ground state. This result establishes that the fractional fermion charge is a well-defined observable.
The essential set of function algebras

Let Jbea compact Hausdorff space and C(X) the Banach algebra of all complex-valued continuous functions on X under the sup-norm. By a function algebra A we mean a closed subalgebra of C(X) which separates points and contains the constant functions. Let S(A) denote the space of maximal ideals of A and let E(A) denote the essential set of A as defined by Bear [l], i.e. E(A) is the hull of the largest closed ideal of C(X) which is contained in A. We will obtain another characterization of the essential set in the case when S(A) =X and thereby obtain some results of a global nature from local hypotheses.
Temporal correlation in cat striate-cortex neural spike trains

The authors draw on point-process theory and wavelet analysis to examine the variability and correlation properties of spike trains from single neurons in the cat striate cortex, under conditions of spontaneous and stimulated (driven) firing. It is not possible to infer the long-term correlation properties of a spike train from measures that reset at short times; thus, often-used spike-train measures, such as the interevent-interval histogram (IIH) and post-stimulus time (PST) histogram, cannot serve this purpose. Rather, the authors make use of the event-number histogram (ENH), also called the spike-number or spike-count distribution. This measure affords the experimenter the opportunity of externally controlling the counting time, T, and therefore the duration over which spike correlations can be viewed. A useful and relatively simple gauge of the correlation properties is obtained from the first two moments of the ENH. In particular, the Fano factor (FF), defined as the ratio of the spike-count variance to the spike-count mean: F(T)=var(N)|N, plotted as a function of the counting time, T, serves this purpose quite well. The FF is a special case of the wavelet Fano factor (WFF) implemented using the Haar wavelet basis.
Entropy and Exergy in the Development of Living Systems : A Case Study of Lake-Ecosystems

The entropy production in lake-ecosystem consists of the entropy production dependent on solar radiation and that independent of solar radiation. These entropy productions are calculated and compared for oligotrophic (not so polluted) Lake Biwa and eutrophic (polluted) Lake Mendota. Based on the results, an entropy law for eutrophication is proposed: Entropy production in lake-ecosystems increases with time in the course of eutrophication. On the contrary, in the senescent stage of lake-ecosystems, the trend will be reversed. By extending and generalizing the arguments, an entropy principle is proposed for the life span of living systems from organisms to ecosystems, that is, entropy production in living systems consists of an early increasing stage, an intermediate/transitional stage and a later decreasing stage. By virtue of the Gouy-Stodola theorem, these tendencies are also applied to exergy destruction, which is a thermodynamical quantity closely related to irreversibility of process like entropy pro.
Predicting the Impact of Climate Change on Severe Wintertime Particulate Pollution Events in Beijing Using Extreme Value Theory

We use extreme value theory to develop point process statistical models relating the probability of extreme winter particulate pollution events in Beijing (“winter haze”) to local meteorological variables. The models are trained with the 2009–2017 record of fine particulate matter concentrations (PM2.5) from the U.S. embassy. We find that 850‐hPa meridional wind velocity (V850) and relative humidity successfully predict the probability for 24‐hr average PM2.5 to exceed 300 μg/m3 (95th percentile of the frequency distribution) as well as higher thresholds. We apply the point process models to mid‐21st century climate projections from the Coupled Model Intercomparison Project Phase 5 model ensemble under two radiative forcing scenarios (RCP8.5 and RCP4.5). We conclude that 21st century climate change alone is unlikely to increase the frequency of severe PM2.5 pollution events (PM2.5 > 300 μg/m3) in Beijing and is more likely to marginally decrease the probability of such events.
Polarization beats in ballistic propagation of exciton-polaritons in microcavities

The emission from a microcavity in the strong coupling regime excited resonantly by linearly polarized light has been measured with spatial, directional, and temporal resolution. We observe ballistic propagation of the excited polaritons as a ring spreading in real space. The linear polarization degree P of the emission at the ring is found to oscillate as a function of the azimuthal angle θ and of time t according to P=sin(2θ)sin(ΩLTt∕2), where ΩLT is the longitudinal-transverse splitting of the exciton-polariton modes. This dependence holds for all investigated excitation energies corresponding to different values of ΩLT. The theoretical model assuming ballistic propagation of exciton polaritons in the specific cavity structure yields a detailed agreement with the experimental data. The observed polarization beats have the same nature as the recently predicted optical spin Hall effect.
Perceptual evaluation of filters controlling source direction : Customized and generalized HRTFs for binaural synthesis

This paper reviews development of spatial auditory display technology based upon 20 years of research evaluating digital filters designed to spatially position auditory images associated with sound sources presented via earphones. The motivation for this review was to attempt to provide clarification regarding some of the issues and assumptions that underlie such research-driven binaural technology development. After a general discussion of research goals and methods, instructive research results are presented to underscore the main points, especially with regard to questions that could serve to stimulate further useful work on directional filter design. These include questions of how best to customize filters for individual users, and, conversely, how to optimize filters for general use. Also considered are the related questions of how best to evaluate the performance of generic Head-Related Transfer Functions (HRTFs), in contrast to those that are measured for the use of a specific individual. At the heart of this review is a focus on the methods that are most appropriate for the evaluation of auditory imagery resulting from synthetic sound spatialization. While a primary goal for binaural synthesis is to spatially position an auditory image, methods typically employed to study the ability of human listeners to spatially localize an actual sound source address only a narrow subset of the issues that are important to the development of adequate spatial auditory display technology.
The evolution of the dust shell of Nova Serpentis 1978

Photometric measurements of Nova Serpentis 1978 from V to 19.5 microns covering the first 240 days of the nova's development are reported. A free-free expansion phase was followed by the condensation of a dust shell that became optically thick at both visible and infrared wavelengths. Carbon grains grew to radii of approximately 0.3 microns during the condensation period. The grains appeared to sputter or evaporate for a period of approximately 100 days following infrared maximum. It is found that the condensed carbon comprised 2% of the ejected mass, which implies that carbon abundance was enhanced in the nova shell. The angular expansion rate of the shell yields a distance of approximately 5 kpc and a luminosity of approximately 3000 solar luminosities for Nova Serpentis 1978.
Nonparametric tests for block experiments

SUMMARY A method is described for constructing nonparametric tests for experiments arranged in blocks when the underlying distributions are of Lehmann's form. In simple cases the resulting test statistics are those that would be obtained by an analysis of variance following a trans- formation of the data into exponential scores. In the past considerable work has been done on examining the power of various standard nonparametric tests under the so-called Lehmann alternative, where the probability in the upper tail of the alternative distribution is a power of the probability in the upper tail of the null distribution. With the exception of certain two-sample tests little effort seems to have been devoted to deriving tests more appropriate to this underlying situation, which is of considerable importance in life testing. In this note it is shown how the condi- tional likelihood approach adopted by Cox (1972) may be used to derive nonparametric test statistics for a variety of situations. Because of their method of construction the resulting tests necessarily have asymptotically optimal properties under the Lehmann alternative, but their small-sample behaviour still needs investigation. In some cases the test derived by this method is a generalization of an existing well-known test.
INEQUALITIES BETWEEN EVENT AND TIME AVERAGES

We consider a stochastic process with an embedded point process in a stationary and ergodic context. Under a “lack of anticipation” assumption for the evolution of the process vis-à-vis the point process, a new better (worse) than used expectation property for the point process, and a monotonicity assumption for the behavior of the process between points, inequalities between event and time averages are obtained. Sample path monotonicity between points is not required (as is the case with existing approaches) and can be replaced with a simple monotonicity requirement for the expected value of the process between points. Inequalities between conditional event and time averages are also examined via a novel argument involving a conditional version of the Palm inversion formula.
ADJACENCY PARAMETERS IN PHONOLOGY

One motivation for nonlinear phonology is the potential for eliminating the devices of linear phonology needed to allow rules to apply to nonadjacent segments. Imposing hierarchical structure on the organization of features within a segment and allowing segments to be unspecified for certain features makes it possible to view apparently longdistance rules as rules operating between segments which are adjacent at a specified level, even though the segments are not adjacent at all levels of representation. This paper presents a theory of phonological adjacency requirements. Locality Theory is defined by a universal Locality Condition, which requires elements to be local within a plane, the Adjacency Parameter, which in turn allows rules to impose further constraints on the maximal distance between interacting segments, and by Transplanar Locality, which bans certain types of relations across featural planes. A survey of phonological processes demonstrates the generality of this theory across feature tiers. *
Melting study of a peridotite KLB-1 to 6.5 GPa, and the origin of basaltic magmas

With a newly established multi-anvil press in the Tokyo Institute of Technology, we have carried out a series of melting experiments on peridotite KLB-1 up to 6.5 GPa. Melt fractions of the peridotite were determined in a wide P-T range using extensive X -ray mapping analysis of run products by EPMA and a digitalized back-scattered electron image technique. Compositions of partial melts and solid residues were determined in the whole melting range up to 6.5 GPa. Given quantitative information on mantle melting, we discuss conditions of melting of various basalt magmas and the nature of their source materials. Our conclusions are consistent with the hypothesis that typical mid oceanic ridge basalts represent low pressure (ca. 1 GPa), low temperature (Tp ≈ 1300 °C) partial melting products of mantle peridotite. Island arc picritic tholeiites may also be regarded as partial melts of a peridotitic source, at 1-2 GPa pressures and Tp ranging from 1400 to 1500 °C. However, proposed primary magmas for Hawaiian tholeiite are difficult to produce by partial melting of typical mantle peridotite at any depth under anhydrous conditions. Source materials for magmas in large hotspots (e.g. Hawaii, Iceland and some continental flood basalts (CFBS)) may be anomalously enriched in FeO and TiO2 relative to typical upper mantle peridotites such as KLB-1.
Effect of Seed Mass and Cotyledon Removal THE EFFECT OF SEED MASS AND COTYLEDON REMOVAL ON THE GERMINATION AND GROWTH OF FLUTED PUMPKIN

INTRODUCTION Seed mass plays a vital role in reproductive biology (Cordazzo 2002). Research has revealed that there is great variation of seed mass both within and between species and even in an individual plant (Leishman & Westby 1994). Bonfil (1998) reported that seedling survival was greatly affected by excision of cotyledons of Quercus rugosa and Q. laurina. Carbon supplies from cotyledons and other carbohydrates reserves apparently enhanced ability of seedlings to cope with herbivory, pests and diseases (Kitajima 2003).
Efficient block preconditioners for the coupled equations of pressure and deformation in highly discontinuous media

Large‐scale simulations of flow in deformable porous media require efficient iterative methods for solving the involved systems of linear algebraic equations. Construction of efficient iterative methods is particularly challenging in problems with large jumps in material properties, which is often the case in geological applications, such as basin evolution at regional scales. The success of iterative methods for this type of problems depends strongly on finding effective preconditioners. This paper investigates how the block‐structured matrix system arising from single‐phase flow in elastic porous media should be preconditioned, in particular for highly discontinuous permeability and significant jumps in elastic properties. The most promising preconditioner combines algebraic multigrid with a Schur complement‐based exact block decomposition. The paper compares numerous block preconditioners with the aim of providing guidelines on how to formulate efficient preconditioners. Copyright © 2010 John Wiley & Sons, Ltd.
Unique nanostructures and enhanced thermoelectric performance of melt-spun BiSbTe alloys

We report a melt spinning technique followed by a quick spark plasma sintering procedure to fabricate high-performance p-type Bi0.52Sb1. 48Te3 bulk material with unique microstructures. The microstructures consist of nanocrystalline domains embedded in amorphous matrix and 5–15 nm nanocrystals with coherent grain boundary. The significantly reduced thermal conductivity leads to a state-of-the-art dimensionless figure of merit ZT∼1.56 at 300 K, more than 50% improvement of that of the commercial Bi2Te3 ingot materials.
Numerical computation of collisionless drift Alfvén turbulence

Collisionless drift waves are studied by means of nonlinear numerical simulations in a three-dimensional sheared slab geometry. The electron dynamics is described by a drift-kinetic equation, and the ions are treated as a cold fluid. The energy spectra of the turbulent fluctuations and the dependence of the resulting anomalous transport on various dimensionless plasma parameters are investigated. It is shown that this model resolves fundamental contradictions between experimental results and linear drift wave theory, especially the dependence of turbulent transport on radial position but also the scaling with ion mass.
On the flow between a rotating and a stationary disk

The analysis and experiments in this paper are restricted to the flow between two coaxial, infinite disks, one rotating and one stationary. The results of numerical calculations show that many solutions can exist for a given Reynolds number Ωl2/v (Ω is the angular velocity of the rotating disk and I is the spacing between the two disks). Out of a greater number of possible solutions, three solution branches have been identified; the branches correspond to one-, two- and three-flow cells in the meridional plane. The one-cell branch has been accorded detailed treatment. Within this branch there are two subbranches. The first, now well documented in the literature, includes solutions from zero to infinite Reynolds number. The latter limiting case is characterized by an inward-flowing boundary layer on the stationary disk and an outward-flowing boundary layer on the rotating disk. In between is a core flow rotating with a constant angular velocity. The second sub-branch of the single-cell flows, apparently unknown heretofore, begins with an infinite Reynolds number, decreases to a minimum and then increases to an infinite Reynolds number again. The first infinite Reynolds number limit again corresponds to two boundary-layer flows separated by a core flow with constantangular velocity opposite in direction to the angular velocity of the rotating disk. The second limiting case of infinite Reynolds number is the free-disk solution of von Kármán (1921). Asymptotic solutions have been obtained which more fully describe the nature of this flow as the Reynolds number increases. The second part of the paper presents experimental measurements corresponding to the Reynolds number range 0–100. Profiles were measured with a hot-wire anemometer. The measurements are in agreement with the first, one-cell branch of solutions. A semi-quantitative evaluation of edge effects is obtained.
Void distribution and bubble motion in bubbly flows in a 4×4 rod bundle. Part I: Experiments

Lack of local void fraction data in a rod bundle makes it difficult to validate a numerical method for predicting gas–liquid two-phase flow in the bundle. Distributions of local void fraction and bubble velocity in each subchannel in a 4×4 rod bundle were, therefore, measured using a double-sensor conductivity probe. Liquid velocity in the subchannel was also measured using laser Doppler velocimetry (LDV) to obtain relative velocity between bubbles and the liquid phase. The size and pitch of rods were 10 and 12.5 mm, respectively. Air and water at atmospheric pressure and room temperature were used for the gas and liquid phases, respectively. The volume fluxes of gas and liquid phases ranged from 0.06 to 0.15 m/s and from 0.9 to 1.5 m/s, respectively. Experimental results showed that the distributions of void fraction in inner and side subchannels depend not only on lift force acting on bubbles but also on geometrical constraints on bubble dynamics, i.e. the effects of rod walls on bubble shape and rise velocity. The relative velocity between bubbles and the liquid phase in the subchannel forms a non-uniform distribution over the cross-section, and the relative velocity becomes smaller as bubbles approach the wall due to the wall effects.
Secondary instability of crossflow vortices and swept-wing boundary-layer transition

Crossflow instability of a three-dimensional boundary layer is a common cause of transition in swept-wing flows. The boundary-layer flow modified by the presence of finite-amplitude crossflow modes is susceptible to high-frequency secondary instabilities, which are believed to harbinger the onset of transition. The role of secondary instability in transition prediction is theoretically examined for the recent swept-wing experimental data by Reibert et al. (1996). Exploiting the experimental observation that the underlying three-dimensional boundary layer is convectively unstable, non-linear parabolized stability equations are used to compute a new basic state for the secondary instability analysis based on a two-dimensional eigenvalue approach. The predicted evolution of stationary crossflow vortices is in close agreement with the experimental data. The suppression of naturally dominant crossflow modes by artificial roughness distribution at a subcritical spacing is also confirmed. The analysis reveals a number of secondary instability modes belonging to two basic families which, in some sense, are akin to the ‘horseshoe’ and ‘sinuous’ modes of the Görtler vortex problem. The frequency range of the secondary instability is consistent with that measured in earlier experiments by Kohama et al. (1991), as is the overall growth of the secondary instability mode prior to the onset of transition (e.g. Kohama et al. 1996). Results indicate that the N-factor correlation based on secondary instability growth rates may yield a more robust criterion for transition onset prediction in comparison with an absolute amplitude criterion that is based on primary instability alone.