Miracle-dz/UniFAR-FTUs huggingface dataset:
Inflated Bendable Eversion Cantilever Mechanism With Inner Skeleton for Increased Stiffness

Inflatable structures used in soft robotics applications have unique characteristics. In particular, the tip-extension structure, which extends the structure from its tip, can grow without creating friction with the environment. However, these inflatable structures need high pressure to maintain their stiffness under various conditions. Excessive inner pressure limits their application in that it prevents the structure from maintaining its curved shape and from complying with specifications. This study aimed to simultaneously lower the pressure and increase the rigidity of the structure. Our work resulted in the proposal of a mechanism that combines a skeleton structure consisting of multi-joint links with functions to increase the rigidity. Insertion of this mechanism into an inflatable structure obviates the need for high inner pressure, yet enables the structure to bend and maintain the intended shape. We devised a design based on rigid articulated links and combined it with a membrane structure that utilizes the advantages of the tip-extension structure. The experimental results show that the payload of the structure designed to operate at low pressure increases compared to that of the membrane-only structure. The findings of this research can be applied to long robots that can be extended into open space without drooping and to mechanisms that enable structures to wrap around the human body.
Exact steady states for quantum quenches in integrable Heisenberg spin chains

What is the long-time behavior of a quantum system after it is brought out of equilibrium? In a generic case, it has been proposed that an effective thermalization occurs, and the local properties of the system can then be described by a thermal Gibbs ensemble. However, in integrable systems, with infinitely many conservation laws, the answer is far more complicated. It was shown in several special cases that the long-time steady state can be exactly described by the so called complete generalized Gibbs ensemble. The latter can be obtained by maximizing the entropy with constraints imposed by the conservation of energy, but also by additional carefully chosen subset of the integrals of motion. In this work, the authors analyze more general initial states, focusing on integrable XXZ Heisenberg spin chains. They find that the complete generalized Gibbs ensemble indeed correctly describes the system at long times after the quench.
Symmetry breaking and universality of decaying MHD Taylor-Green flows

We investigate the evolution and stability of a decaying magnetohydrodynamic (MHD) Taylor-Green flow. The chosen flow has been shown to result in a steep total energy spectrum with power law behaviour $k^{-2}$. We investigate the symmetry breaking of this flow by exciting perturbations of different amplitudes. It is shown that for any finite amplitude perturbation there is a high enough Reynolds number for which the perturbation will grow enough at the peak of dissipation rate resulting to a non-linear feedback in the flow and subsequently break the Taylor-Green symmetries. In particular, we show that symmetry breaking at large scales occurs if the amplitude of the perturbation is $\rho_{crit} \sim Re^{-1}$ and at small scales occurs if $\rho_{crit} \sim Re^{-3/2}$. This symmetry breaking modifies the scaling laws of the energy spectra at the peak of dissipation rate away from the $k^{-2}$ scaling and towards the classical $k^{-5/3}$ and $k^{-3/2}$ power laws.
Phases of driven two-level systems with nonlocal dissipation

We study an array of two-level systems arranged on a lattice and illuminated by an external plane wave which drives a dipolar transition between the two energy levels. In this set up, the two-level systems are coupled by dipolar interactions and subject to nonlocal dissipation, so behave as an open many-body quantum system. We investigate the long-time dynamics of the system at the mean-field level, and use this to determine a phase diagram as a function of external drive and detuning. We find a multitude of phases including antiferromagnetism, spin density waves, oscillations and phase bistabilities. We investigate these phases in more detail and explain how nonlocal dissipation plays a role in the long-time dynamics. Furthermore, we discuss what features would survive in the full quantum description.
Pure Fulde-Ferrell-Larkin-Ovchinnikov state in optical lattices

Department of Physics, Zhejiang Normal University, Jinhua, Zhejiang Province, 321004, China(Dated: October 11, 2011)We study the phase diagram of a one-dimensional, two-component attractive fermions on optical latticesin an off-diagonal conﬁnement. We identify in this system a pure Fulde-Ferrell-Larkin-Ovchinnikov (FFLO)state with spatially modulated superﬂuidity and polarizat ion in a large parameter window, which provides aneasier playground to detect the FFLO state experimentally. The clear signature of FFLO state is analyzed in theground state properties, the pair correlation functions, and the magnetic structure factor, using the density-matrixrenormalization group method.
Energy Minimization of Dynamic Multi-UAV Communication Network for Cooperative MultiHop Data Gathering

This study proposes a minimum-energy operational planning problem for multiple unmanned aerial vehicles (UAVs) conducting a cooperative multihop data-gathering mission. A multi-UAV ad hoc network collects data from multiple sources and transmits them to a ground base station. The proposed mixed-integer nonlinear programming formulation simultaneously determines cooperative task allocation, data gathering schedule, dynamic aerial data flow, and UAV trajectories to minimize operational energy consumption. A hierarchical two-phase solution procedure that decomposes the original problem into a series of less complex problems and solves them efficiently is developed. The effectiveness of the proposed formulation and the solution procedure is demonstrated through numerical experiments and comparison with benchmarking operational schemes.
Characteristic Polynomials of Random Matrices and Noncolliding Diffusion Processes

We consider the noncolliding Brownian motion (BM) with $N$ particles starting from the eigenvalue distribution of Gaussian unitary ensemble (GUE) of $N \times N$ Hermitian random matrices with variance $\sigma^2$. We prove that this process is equivalent with the time shift $t \to t+\sigma^2$ of the noncolliding BM starting from the configuration in which all $N$ particles are put at the origin. In order to demonstrate nontriviality of such equivalence for determinantal processes, we show that, even from its special consequence, determinantal expressions are derived for the ensemble averages of products of characteristic polynomials of random matrices in GUE. Another determinantal process, noncolliding squared Bessel process with index $\nu >-1$, is also studied in parallel with the noncolliding BM and corresponding results for characteristic polynomials are given for random matrices in the chiral GUE as well as in the Gaussian ensembles of class C and class D.
A SPECTROSCOPICALLY CONFIRMED X-RAY CLUSTER AT z = 1.62 WITH A POSSIBLE COMPANION IN THE SUBARU/XMM-NEWTON DEEP FIELD

We report on a confirmed galaxy cluster at z = 1.62. We discovered two concentrations of galaxies at z ∼ 1.6 in the Subaru/XMM-Newton deep field based on deep multi-band photometric data. We made a near-IR spectroscopic follow-up observation of them and confirmed several massive galaxies at z = 1.62. One of the two is associated with an extended X-ray emission at 4. 5σ on a scale of 0. ′5, which is typical of high-z clusters. The X-ray detection suggests that it is a gravitationally bound system. The other one shows a hint of an X-ray signal, but only at 1.5σ, and we obtained only one secure redshift at z = 1.62. We are not yet sure if this is a collapsed system. The possible twins exhibit a clear red sequence at K < 22 and seem to host relatively few number of faint red galaxies. Massive red galaxies are likely old galaxies—they have colors consistent with the formation redshift of zf = 3, and a spectral fit of the brightest confirmed member yields an age of 1.8+0.1−0.2 Gyr with a mass of 2.5+0.2−0.1 × 1011 M☉. Our results show that it is feasible to detect clusters at z > 1.5 in X-rays and also to perform detailed analysis of galaxies in them with the existing near-IR facilities on large telescopes.
Stochastic bias in multidimensional excursion set approaches

We describe a simple fully analytic model of the excursion set approach associated with two Gaussian random walks: the first walk represents the initial overdensity around a protohalo, and the second is a crude way of allowing for other factors which might influence halo formation. This model is richer than that based on a single walk, because it yields a distribution of heights at first crossing. We provide explicit expressions for the unconditional first crossing distribution which is usually used to model the halo mass function, the progenitor distributions, and the conditional distributions from which correlations with environment are usually estimated. These latter exhibit perhaps the simplest form of what is often called nonlocal bias, and which we prefer to call stochastic bias, since the new bias effects arise from `hidden-variables' other than density, but these may still be defined locally. We provide explicit expressions for these new bias factors. We also provide formulae for the distribution of heights at first crossing in the unconditional and conditional cases. In contrast to the first crossing distribution, these are exact, even for moving barriers, and for walks with correlated steps. The conditional distributions yield predictions for the distribution of halo concentrations at fixed mass and formation redshift. They also exhibit assembly bias like effects, even when the steps in the walks themselves are uncorrelated. Finally, we show how the predictions are modified if we add the requirement that halos form around peaks: these depend on whether the peaks constraint is applied to a combination of the overdensity and the other variable, or to the overdensity alone. Our results demonstrate the power of requiring models to reproduce not just halo counts but the distribution of overdensities at fixed protohalo mass as well.
Galaxy evolution in cosmological simulations with outflows ― I. Stellar masses and star formation rates

We examine the growth of the stellar content of galaxies from z = 3 → 0 in cosmological hydrodynamic simulations incorporating parametrized galactic outflows. Without outflows, galaxies overproduce stellar masses (M * ) and star formation rates (SFRs) compared to observations. Winds introduce a three-tier form for the galaxy stellar mass and star formation rate functions, where the middle tier depends on the differential (i.e. mass-dependent) recycling of ejected wind material back into galaxies. A tight M * ―SFR relation is a generic outcome of all these simulations and its evolution is well described as being powered by cold accretion, although current observations at z ≳ 2 suggest that the star formation in small early galaxies must be highly suppressed. Roughly, one-third of z = 0 galaxies at masses below M * are satellites and the star formation in satellites is not much burstier than in centrals. All models fail to suppress the star formation and stellar mass growth in massive galaxies at z ≲ 2, indicating the need for an external quenching mechanism such as black hole feedback. All models also fail to produce dwarfs as young and rapidly star forming as observed. An outflow model following scalings expected for momentum-driven winds broadly matches the observed galaxy evolution around M * from z = 0 to 3, which is a significant success since these galaxies dominate cosmic star formation, but the failures at higher and lower masses highlight the challenges still faced by this class of models. We argue that central star-forming galaxies are well described as living in a slowly evolving equilibrium between inflows from gravity and recycled winds, star formation, and strong and ubiquitous outflows that regulate how much inflow forms into stars. Star-forming galaxy evolution is thus primarily governed by the continual cycling of baryons between galaxies and intergalactic gas.
A search for rocky planets transiting brown dwarfs

Exoplanetary science has reached a historic moment. The James Webb Space Telescope will be capable of probing the atmospheres of rocky planets, and perhaps even search for biologically produced gases. However this is contingent on identifying suitable targets before the end of the mission. A race therefore, is on, to find transiting planets with the most favorable properties, in time for the launch. Here, we describe a realistic opportunity to discover extremely favorable targets - rocky planets transiting nearby brown dwarfs - using the Spitzer Space Telescope as a survey instrument. Harnessing the continuous time coverage and the exquisite precision of Spitzer in a 5,400 hour campaign monitoring nearby brown dwarfs, we will detect a handful of planetary systems with planets as small as Mars. The survey we envision is a logical extension of the immense progress that has been realized in the field of exoplanets and a natural outcome of the exploration of the solar neighborhood to map where the nearest habitable rocky planets are located (as advocated by the 2010 Decadal Survey). Our program represents an essential step towards the atmospheric characterization of terrestrial planets and carries the compelling promise of studying the concept of habitability beyond Earth-like conditions. In addition, our photometric monitoring will provide invaluable observations of a large sample of nearby brown dwarfs situated close to the M/L transition. This is why, we also advocate an immediate public release of the survey data, to guarantee rapid progress on the planet search and provide a treasure trove of data for brown dwarf science.
Towards a future-proof climate database for European energy system studies

In 2013, the European Network of Transmission System Operators (TSOs) for electricity (ENTSO-E) created the Pan-European Climate Database (PECD), a tool that has underpinned most studies conducted by TSOs ever since. So far, the different versions of the PECD have used so-called modern-era ‘reanalysis’ products that represent a gridded amalgamation of historical conditions from observations. However, scientific evidence suggests, and recent European regulation requires, that power system adequacy studies should take climate change into account when estimating the future potential of variable renewable resources, such as wind, solar and hydro, and the impact of temperature on electricity demand. This paper explains the need for future climate data in energy systems studies and provides high-level recommendations for building a future-proof reference climate dataset for TSOs, not just in Europe, but also globally.
Synthesis and Iodine Adsorption Properties of Organometallic Copolymers with Propeller-Shaped Fe(II) Clathrochelates Bridged by Different Diaryl Thioether and Their Oxidized Sulfone Derivatives

Three organometallic copolymers, ICP1-3, containing iron(II) clathrochelate units with cyclohexyl lateral groups and interconnected by various thioether derivatives were synthesized. The reaction of the latter into their corresponding OICP1-3 sulfone derivatives was achieved quantitatively using mild oxidation reaction conditions. The target copolymers, ICP1-3 and OICP1-3, were characterized by various instrumental analysis techniques, and their iodine uptake studies disclosed excellent iodine properties, reaching a maximum of 360 wt. % (qe = 3600 mg g−1). The adsorption mechanisms of the copolymers were explored using pseudo-first-order and pseudo-second-order kinetic models. Furthermore, regeneration tests confirmed the efficiency of the target copolymers for their iodine adsorption even after several adsorption-desorption cycles.
Quasar emission lines, radio structures and radio unification

Unified schemes of radio sources, which account for different types of radio AGN in terms of anisotropic radio and optical emission, together with different orientations of the ejection axis to the line of sight, have been invoked for many years. Recently, large samples of optical quasars, mainly from the Sloan Digital Sky Survey, together with large radio samples, such as FIRST, have become available. These hold the promise of providing more stringent tests of unified schemes but, compared to previous samples, lack high resolution radio maps. Nevertheless they have been used to investigate unified schemes, in some cases yielding results which appear inconsistent with such theories. Here we investigate using simulations how the selection effects to which such investigations are subject can influence the conclusions drawn. In particular, we find that the effects of limited resolution do not allow core-dominated radio sources to be fully represented in the samples, that the effects of limited sensitivity systematically exclude some classes of sources and the lack of deep radio data make it difficult to decide to what extent closely separated radio sources are associated. Nevertheless, we conclude that relativistic unified schemes are entirely compatible with the current observational data. For a sample selected from SDSS and FIRST which includes weak-cored triples we find that the equivalent width of the [OIII] emission line decreases as core-dominance increases, as expected, and also that core-dominated quasars are optically brighter than weak-cored quasars.
A complete sample of bright Swift short gamma-ray bursts

We present a carefully selected sample of short gamma-ray bursts (SGRBs) observed by the Swift satellite up to June 2013. Inspired by the criteria we used to build a similar sample of bright long GRBs (the BAT6 sample), we selected SGRBs with favorable observing conditions for the redshift determination on ground, ending up with a sample of 36 events, almost half of which with a redshift measure. The redshift completeness increases up to about 70% (with an average redshift value of z = 0.85) by restricting to those events that are bright in the 15-150 keV Swift Burst Alert Telescope energy band. Such flux-limited sample minimizes any redshift-related selection effects, and can provide a robust base for the study of the energetics, redshift distribution and environment of the Swift bright population of SGRBs. For all the events of the sample we derived the prompt and afterglow emission in both the observer and (when possible) rest frame and tested the consistency with the correlations valid for long GRBs. The redshift and intrinsic X-ray absorbing column density distributions we obtain are consistent with the scenario of SGRBs originated by the coalescence of compact objects in primordial binaries, with a possible minor contribution (�10%– 25%) of binaries formed by dynamical capture (or experiencing large natal kicks). This sample is expected to significantly increase with further years of Swift activity.
Gravitational Lensing by Spherical Lenses

In this work we introduced a new proposal to study the gravitational lensing theory by spherical lenses, starting from its surface mass density ∑(x) written in terms of a decreasing function f of a dimensionless coordinate x on the lens plane. The main result is the use of the function f(x) to find directly the lens properties, at the same time that the lens problem is described by a first order differential equation which encodes all information about the lens. SIS and NIS profiles are used as examples to find their functions f(x). Using the Poisson equation we find that the deflection angle is directly proportional to f(x), and therefore the lens equation can be written in terms of the function and the parameters of the lens. The critical and caustic curves, as well as image formation and magnification generated by the lens are analyzed. As an example of this method, the properties of a lens modeled by a NFW profile are determined. Although the puntual mass is spherically symmetric, its mass density is not continuous so that its f(x) function is discussed in Appendix 1.
Wikstroemiafragrans (Thymelaeaceae, Daphneae), a new species from Mount Danxia, China based on morphological and molecular evidence

﻿Abstract A new species, Wikstroemiafragrans (Thymelaeaceae, Daphneae), from Danxiashan National Park, Shaoguan, Guangdong of China is described and illustrated. It is similar to the sympatric W.trichotoma, but can be differentiated easily from the latter by its shorter racemose inflorescences, yellowish green calyx tube, and smaller leaves. It also resembles the allopatric W.fargesii, but differs from it by its strigose-pubescent ovary and disk scale that is 2- or 3-dentate apically. Phylogenetic analysis using the nuclear DNA internal transcribed spacer (ITS) region revealed that W.fragrans falls within the Wikstroemia clade; based on current sampling, W.fragrans is closely-related to W.capitata. It is also the first species of Wikstroemia known to be endemic to the Danxia landform and is classified provisionally as Critically Endangered according to the IUCN Red List Categories and Criteria.
Coupling of a locally implanted rare-earth ion ensemble to a superconducting micro-resonator

We demonstrate the coupling of rare-earth ions locally implanted in a substrate (Gd$^{3+}$ in Al$_{2}$O$_{3}$) to a superconducting NbN lumped-element micro-resonator. The hybrid device is fabricated by a controlled ion implantation of rare-earth ions in well-defined micron-sized areas, aligned to lithographically defined micro-resonators. The technique does not degrade the internal quality factor of the resonators which remain above $10^{5}$. Using microwave absorption spectroscopy we observe electron-spin resonances in good agreement with numerical modelling and extract corresponding coupling rates of the order of $1$ MHz and spin linewidths of $50 - 65$ MHz.
Gated Recurrent Unit Network for Psychological Stress Classification Using Electrocardiograms from Wearable Devices

In recent years, research on human psychological stress using wearable devices has gradually attracted attention. However, the physical and psychological differences among individuals and the high cost of data collection are the main challenges for further research on this problem. In this work, our aim is to build a model to detect subjects’ psychological stress in different states through electrocardiogram (ECG) signals. Therefore, we design a VR high-altitude experiment to induce psychological stress for the subject to obtain the ECG signal dataset. In the experiment, participants wear smart ECG T-shirts with embedded sensors to complete different tasks so as to record their ECG signals synchronously. Considering the temporal continuity of individual psychological stress, a deep, gated recurrent unit (GRU) neural network is developed to capture the mapping relationship between subjects’ ECG signals and stress in different states through heart rate variability features at different moments, so as to build a neural network model from the ECG signal to psychological stress detection. The experimental results show that compared with all comparison methods, our method has the best classification performance on the four stress states of resting, VR scene adaptation, VR task and recovery, and it can be a remote stress monitoring solution for some special industries.