Miracle-dz/UniFAR-FTUs huggingface dataset:
The k-local Pauli Commuting Hamiltonians Problem is in P

Given a Hamiltonian that is a sum of commuting few-body terms, the commuting Hamiltonian problem is to determine if there exists a quantum state that is the simultaneous eigenstate of all of these terms that minimizes each term individually. This problem is known to be in the complexity class quantum Merlin-Arthur, but is widely thought to not be complete for this class. Here we show that a limited form of this problem when the individual terms are all made up of tensor products of Pauli matrices is efficiently solvable on a classical computer and thus in the complexity class P. The problem can be thought of as the classical XOR-SAT problem over a symplectic vector space. This class of problems includes instance Hamiltonians whose ground states possess topological entanglement, thus showing that such entanglement is not always a barrier for the more general problem.
Limit curve theorems in Lorentzian geometry

The subject of limit curve theorems in Lorentzian geometry is reviewed. A general limit curve theorem is formulated, which includes the case of converging curves with endpoints and the case in which the limit points assigned since the beginning are one, two, or at most denumerable. Some applications are considered. It is proved that in chronological spacetimes, strong causality is either everywhere verified or everywhere violated on maximizing lightlike segments with open domain. As a consequence, if in a chronological spacetime two distinct lightlike lines intersect each other then strong causality holds at their points. Finally, it is proved that two distinct components of the chronology violating set have disjoint closures or there is a lightlike line passing through each point of the intersection of the corresponding boundaries.
GALAXY CLUSTERS AT HIGH REDSHIFT AND EVOLUTION OF BRIGHTEST CLUSTER GALAXIES

Identification of high-redshift clusters is important for studies of cosmology and cluster evolution. Using photometric redshifts of galaxies, we identify 631 clusters from the Canada–France–Hawaii Telescope (CFHT) wide field, 202 clusters from the CFHT deep field, 187 clusters from the Cosmic Evolution Survey (COSMOS) field, and 737 clusters from the Spitzer Wide-area InfraRed Extragalactic Survey (SWIRE) field. The redshifts of these clusters are in the range 0.1 ≲ z ≲ 1.6. Merging these cluster samples gives 1644 clusters in the four survey fields, of which 1088 are newly identified and more than half are from the large SWIRE field. Among 228 clusters of z ⩾ 1, 191 clusters are newly identified, and most of them from the SWIRE field. With this large sample of high-redshift clusters, we study the color evolution of the brightest cluster galaxies (BCGs). The r′ − z′ and r+ − m3.6 μm colors of the BCGs are consistent with a stellar population synthesis model in which the BCGs are formed at redshift zf ⩾ 2 and evolved passively. The g′ − z′ and B − m3.6 μm colors of the BCGs at redshifts z > 0.8 are systematically bluer than the passive evolution model for galaxies formed at zf ∼ 2, indicating star formation in high-redshift BCGs.
Suppression of the stochastic fluctuations of suspended nanowires by temperature-induced single-electron tunneling

We theoretically investigate the electromechanical properties of freely suspended nanowires that are in tunneling contact with the tip of a scanning tunneling microscope (STM) and two supporting metallic leads. The aim of our analysis is to characterize the fluctuations of the dynamical variables of the nanowire when a temperature drop is maintained between the STM tip and the leads, which are all assumed to be electrically grounded. By solving a quantum master equation that describes the coupled dynamics of electronic and mechanical degrees of freedom, we found that the stationary state of the mechanical oscillator has a Gaussian character, but that the amplitude of its root-mean square center-of-mass fluctuations is smaller than would be expected if the system were coupled only to the leads at thermal equilibrium.
The Globular Cluster Systems around NGC 3311 and NGC 3309

We present extensive new photometry in (g′, i′) of the large globular cluster (GC) system around NGC 3311, the central cD galaxy in the Hydra cluster. Our GMOS data cover a 5.5′ field of view and reach a limiting magnitude i′ ≃ 26.0, about 0.5 mag fainter than the turnover point of the GC luminosity function. We find that NGC 3311 has a huge population of ≃16,000 GCs, closely similar to the prototypical “high specific frequency” Virgo giant M87. The color-magnitude distribution shows that the metal-poor “blue” GC sequence and the more metal-rich “red” sequence are both present, with nearly equal numbers of clusters. Bimodal fits to the color distributions confirm that the blue sequence shows the same trend of progressively increasing metallicity with GC mass that has previously been found in many other large galaxies; the correlation we find corresponds to a scaling of GC metallicity with mass of Z ∼ M0.6. By contrast, the red sequence shows no change of mean metallicity with mass but does show an upward extension to much higher than normal luminosity into the UCD-like range, strengthening the potential connections between massive GCs and UCDs. The GC luminosity function, which we measure down to the turnover point at MI≃ − 8.4, also has a normal form like those in other giant ellipticals. Within the Hydra field, another giant elliptical NGC 3309 is sitting just 100″ from the cD NGC 3311. We use our data to solve simultaneously for the spatial structure and total GC populations of both galaxies. Their specific frequencies are SN(N 3311) = 12.5 ± 1.5 and SN(N 3309) = 0.6 ± 0.4. NGC 3311 is completely dominant and entirely comparable with other cD-type systems such as M87 in Virgo.
Reversing cooling flows with AGN jets: shock waves, rarefaction waves and trailing outflows

The cooling flow problem is one of the central problems in galaxy clusters, and active galactic nucleus (AGN) feedback is considered to play a key role in offsetting cooling. However, how AGN jets heat and suppress cooling flows remains highly debated. Using an idealized simulation of a cool-core cluster, we study the development of central cooling catastrophe and how a subsequent powerful AGN jet event averts cooling flows, with a focus on complex gasdynamical processes involved. We find that the jet drives a bow shock, which reverses cooling inflows and overheats inner cool core regions. The shocked gas moves outward in a rarefaction wave, which rarefies the dense core and adiabatically transports a significant fraction of heated energy to outer regions. As the rarefaction wave propagates away, inflows resume in the cluster core, but a trailing outflow is uplifted by the AGN bubble, preventing gas accumulation and catastrophic cooling in central regions. Inflows and trailing outflows constitute meridional circulations in the cluster core. At later times, trailing outflows fall back to the cluster centre, triggering central cooling catastrophe and potentially a new generation of AGN feedback. We thus envisage a picture of cool cluster cores going through cycles of cooling-induced contraction and AGN-induced expansion. This picture naturally predicts an anti-correlation between the gas fraction (or X-ray luminosity) of cool cores and the central gas entropy, which may be tested by X-ray observations.
Barefoot pressure image recognition and analysis in natural walking state based on selective fusion attention network

Footprint is a human biological trait with a high extraction rate from crime scenes. It plays an essential role in criminal investigation and security operations. The majority of footprint studies are currently conducted under controlled conditions. However, footprints formed under natural walking are affected by physiological and behavioral characteristics such as posture and walking state, and have variability, which makes it difficult to accurately identify footprints. In this paper, multi-state barefoot pressure images under natural walking state are taken as the research object, and the selective attention network is used for high precision recognition. It can provide a theoretical foundation as well as technical support for later comparison and identification of footprints on-site.
A metrics-based recommendation strategy for code obfuscation

Obfuscation is a method of endogenous security commonly used to thwart software vulnerabilities exploitation and protect important properties such as intellectual property rights, software algorithms and user privacy. Numerous obfuscation techniques and products have been developed after decades of research while it is hard for users to are easy to figure out how to apply these obfuscation rules properly or if a program is obfuscated sufficiently. To solve this problem, this paper proposes a recommendation strategy for code obfuscation based on comprehensive metrics, providing a new scope for obfuscation development and applications. The strategy was implemented and verified on obfuscators and a suit of program benchmarks, demonstrating the strategy could obfuscate programs sufficiently with cost reduced by 30% within five obfuscation rules in average.
High-resolution spectroscopy of the extended narrow-line region of IC 5063 and NGC 7212

We studied the properties of the gas of the extended narrow line region (ENLR) of two Seyfert 2 galaxies: IC 5063 and NGC 7212. We analysed high resolution spectra to investigate how the main properties of this region depend on the gas velocity. We divided the emission lines in velocity bins and we calculated several line ratios. Diagnostic diagrams and SUMA composite models (photo-ionization + shocks), show that in both galaxies there might be evidence of shocks significantly contributing in the gas ionization at high |V|, even though photo-ionization from the active nucleus remains the main ionization mechanism. In IC 5063 the ionization parameter depends on V and its trend might be explained assuming an hollow bi-conical shape for the ENLR, with one of the edges aligned with the galaxy disk. On the other hand, NGC 7212 does not show any kind of dependence. The models show that solar O/H relative abundances reproduce the observed spectra in all the analysed regions. They also revealed an high fragmentation of the gas clouds, suggesting that the complex kinematics observed in these two objects might be caused by interaction between the ISM and high velocity components, such as jets.
Constraints of the compactness of the isolated neutron stars via X-ray phase-resolved spectroscopy

Abstract A model with a condensed iron surface and partially ionized hydrogen-thin atmosphere allows us to fit simultaneously the observed general spectral shape and the broad absorption feature (observed at 0.3 keV) in different spin phases of the isolated neutron star RBS 1223. We constrain some physical properties of the X-ray emitting areas, i.e. the temperatures (Tpole1 ~ 105 eV, Tpole2 ~ 99 eV), magnetic field strengths (Bpole1 ≈ Bpole2 ~ 8.6 × 1013 G) at the poles, and their distribution parameters (a1 ~ 0.61, a2 ~ 0.29, indicating an absence of strong toroidal magnetic field component). In addition, we are able to place some constraints on the geometry of the emerging X-ray emission and the gravitational redshift (z ~ 0.160.03−0.01) of the isolated neutron star RBS 1223.
Scrape-Off Layer Turbulence in Tokamaks Simulated with a Continuum Gyrokinetic Code

We are developing a new continuum gyrokinetic code, Gkeyll, for use in edge plasma simulations, and here present initial simulations of turbulence on open field lines with model sheath boundary conditions. The code implements an energy conserving discontinuous Galerkin scheme, applicable to a general class of Hamiltonian equations. Several applications to test problems have been done, including a calculation of the parallel heat-flux on divertor plates resulting from an ELM crash in JET, for a 1x/1v SOL scenario explored previously, where the ELM is modeled as a time-dependent intense upstream source. Here we present initial simulations of turbulence on open field lines in the LAPD linear plasma device. We have also done simulations in a helical open-field-line geometry. While various simplifications have been made at present, this still includes some of the key physics of SOL turbulence, such as bad-curvature drive for instabilities and rapid parallel losses with sheath boundary conditions. This is useful for demonstrating the overall feasibility of this approach and for initial physics studies of SOL turbulence. We developed a novel version of DG that uses Maxwellian-weighted basis functions while still preserving exact particle and energy conservation. The Maxwellian-weighted DG method achieves the same error with 4 times less computational cost in 1v, or 16 times lower cost in the 2 velocity dimensions of gyrokinetics (assuming memory bandwidth is the limiting factor).
Hidden topological angles and Lefschetz thimbles

We demonstrate the existence of hidden topological angles (HTAs) in a large class of quantum field theories and quantum mechanical systems. HTAs are distinct from theta-parameters in the lagrangian. They arise as invariant angle associated with saddle points of the complexified path integral and their descent manifolds (Lefschetz thimbles). Physical effects of HTAs become most transparent upon analytic continuation in n f to non-integer number of flavors, reducing in the integer n f limit to a Z2 valued phase difference between dominant saddles. In N = 1 super Yang-Mills theory we demonstrate the microscopic mechanism for the vanishing of the gluon condensate. The same effect leads to an anomalously small condensate in a QCD-like SU(N) gauge theory with fermions in the two-index representation. The basic phenomenon is that, contrary to folklore, the gluon condensate can receive both positive and negative contributions in a semi-classical expansion. In quantum mechanics, a HTA leads to a difference in semi-classical expansion of integer and half-integer spin particles.
MORPHOLOGICAL EVOLUTION OF GALAXIES FROM ULTRA-DEEP HUBBLE SPACE TELESCOPE WIDE FIELD CAMERA 3 IMAGING: THE HUBBLE SEQUENCE AT z ∼ 2

We use ultra-deep Hubble Space Telescope Wide Field Camera 3/infrared imaging of the Hubble Ultra Deep Field to investigate the rest-frame optical morphologies of a mass-selected sample of galaxies at z ∼ 2. We find a large variety of galaxy morphologies, ranging from large, blue, disk-like galaxies to compact, red, early-type galaxies. We derive rest-frame u − g color profiles for these galaxies and show that most z ∼ 2 galaxies in our sample have negative color gradients such that their cores are red. Although these color gradients may partly be caused by radial variations in dust content, they point to the existence of older stellar populations in the centers of z ∼ 2 galaxies. This result is consistent with an “inside-out” scenario of galaxy growth. We find that the median color gradient is fairly constant with redshift: (Δ(u − grest)/Δ(log r))median = −0.47, −0.33, and −0.46 for z ∼ 2, z ∼ 1, and z = 0, respectively. Using structural parameters derived from surface brightness profiles we confirm that at z ∼ 2 galaxy morphology correlates well with specific star formation rate. At the same mass, star-forming galaxies have larger effective radii, bluer rest-frame u − g colors, and lower Sérsic indices than quiescent galaxies. These correlations are very similar to those at lower redshift, suggesting that the relations that give rise to the Hubble sequence at z = 0 are already in place for massive galaxies at this early epoch.
Multi-agent-based microgrid cluster power coordinated autonomous control strategy

With the emergence of environmental protection, energy crisis and other problems, distributed photovoltaic microgrid has received wide attention from various countries. The traditional distribution grid dispatching system to monitor the microgrid makes most of the distributed power sources out of control, so it is very important to research and innovate the new microgrid operation mode. By interconnecting microgrids with similar geographic areas and related characteristics electrically and communicatively, and interacting with the distribution grid through a unique access point, microgrid clusters are formed, which is a higher level of distributed power structure. For the stability problem of autonomous operation of microgrid clusters, multi-agent microgrid clusters can not only solve the autonomous operation of the grid, but also make the microgrid with higher stability. In this paper, a coordinated autonomous control strategy for microgrid clusters with ring-type multi-agent is proposed. The method uses a ring network structure between agents to control each microgrid. In this approach, Agents communicate with each other and microgrid units are electrically interconnected to form microgrid clusters with stable power output. Finally, the PSCAD platform simulation verifies the stability of autonomous operation of microgrid clusters with multiple Agents.
Dominance of magnetic cataclysmic variables in the resolved Galactic ridge X‐ray emission of the limiting window

The diffuse appearance of the Galactic ridge X-ray emission has been puzzling since its discovery due to the lack of compelling theories for sustainable hot diffuse X-ray emission in the Galactic plane. Recently, Revnivtsev et al. claimed that ∼90 per cent of the 6.5–7.1 keV X-ray flux from a small section of a low-extinction region at 1°. 4 south of the Galactic Centre has been resolved to discrete sources with erg s−1 cm−2, using ultradeep (1 Ms) observations made by the Chandra X-ray Observatory. They also concluded that coronally active stars such as active binaries (ABs) contribute ∼60 per cent of the resolved flux. However, our recent discovery of a large population of magnetic cataclysmic variables (MCVs) in the same region suggests their significant role in the resolved hard X-ray flux. In addition, deep X-ray surveys of other several Galactic bulge fields over the past decade have indicated that MCVs are likely the major contributor in the hard X-ray emission above 2–3 keV. To solve this mystery, we have conducted an independent in-depth analysis of discrete X-ray sources in the low-extinction region. The total fraction of the 6.5–7.1 keV flux we can confidently claim as resolved is ∼70–80 per cent, which largely agrees with Revnivtsev et al., but leaves some room for diffuse components. However, despite the various attempts, we consistently find that the resolved hard X-ray flux above 3 keV is dominated by relatively bright, hard X-ray sources such as MCVs, whereas the contribution from relatively faint, soft sources such as ABs is below 20 per cent. We describe in detail our analysis procedure in order to elucidate possible origins of the discrepancy.
Comparison of dynamic models for the lower limb exoskeleton based on absolute and relative coordinates

A precise and accurate dynamic model of the lower limb exoskeleton is particularly important for the optimization of the exoskeleton mechanical structure parameters and the design of the control system. Different scholars choose different ways of modeling, which can be generally based on absolute coordinates and relative coordinates. In order to analyze the correctness of the two modeling methods, the dynamic model of the lower limb exoskeleton with 2 degrees of freedom in absolute coordinates and relative coordinates is established by using Lagrange equation. The contribution of this paper is that by comparing the torque expressions of hip and knee joint under the two modeling methods and combining with the derivation process, the correctness of the dynamic model under the two coordinate systems is qualitatively analyzed. This provides a reference for researchers to accurately model the lower limb exoskeleton.
Posterior hemivertebra resection and reconstruction for the correction of old AO type B2.3 thoracic fracture kyphosis: A case report

Background Post-traumatic malunion is one of the main causes of kyphosis and usually has serious consequences. We report a case of kyphosis caused by an old AO type B2.3 thoracic fracture, which was corrected with posterior hemivertebra resection and reconstruction. Case presentation A 41-year-old male was diagnosed with kyphosis caused by an old AO type B2.3 thoracic fracture. Preoperative examination and preparation were performed. His exam images showed a comminuted fracture in the left half of the T12 vertebral body, while chance-type fractures were seen in the right half of T12 vertebral body and its accessories. During the operation, posterior hemivertebra resection and reconstruction techniques were used to remove nearly half of the left vertebral body of the affected vertebra, preserve the right vertebral body and the facet joints of the affected vertebra, correct the kyphosis, and rebuild spinal stability. The patient's low back pain was completely relieved, and his thoracic kyphosis was corrected at the seventh post-operative day. CT reconstruction of the spine showed that the residual vertebrae healed well during his nine- and 18-month follow-ups. Continuous callus formation was observed inside and outside of the titanium cage at the reconstructed site, and there was no sign of subsidence of the titanium cage. The heights between the vertebrae were restored to within normal ranges and the physiological curvature of the thoracolumbar spine was achieved. The patient recovered well. Conclusion This operation preserved the hemivertebral body and facet joints, and maintains intervertebral height and local stability, thus avoiding titanium cage collapse, titanium cage movement, and other complications. This surgical approach is ideal for treating complex thoracic vertebral kyphosis caused by old fractures, and is worth utilizing in the clinic.
He 3 on preplated graphite

By using the diffusion Monte Carlo method, we obtained the full phase diagram of $^{3}\mathrm{He}$ on top of graphite preplated with a solid layer of $^{4}\mathrm{He}$. All the $^{4}\mathrm{He}$ atoms of the substrate were explicitly considered and allowed to move during the simulation. We found that the ground state is a liquid of density $0.007\ifmmode\pm\else\textpm\fi{}0.001$ ${\AA{}}^{\ensuremath{-}2}$, in good agreement with available experimental data. This is significantly different from the case of $^{3}\mathrm{He}$ on clean graphite, in which both theory and experiment agree on the existence of a gas-liquid transition at low densities. Upon an increase in $^{3}\mathrm{He}$ density, we predict a first-order phase transition between a dense liquid and a registered 7/12 phase, the 4/7 phase being found metastable in our calculations. At larger second-layer densities, a final transition is produced to an incommensurate triangular phase.
Optimal capacity allocation method of multivariate composite energy storage system considering service life

Compound energy storage has been widely used in practice, but there is no effective method to realize the optimal capacity allocation of multiple compound energy storage. This paper presents a multi-objective compound energy storage optimal allocation model and method based on economy, environmental protection and reliability. Firstly, the life quantitative model of each component of the combined energy storage system is established. Secondly, the distribution network structure and the efficiency index of the energy storage system are proposed. Then, the joint optimal configuration model of the combined energy storage system is established. Finally, the proposed method is verified by an example simulation.