124 research outputs found
Multipartite entanglement detection via generalized Wigner-Yanase skew information
The detection of multipartite entanglement in multipartite quantum systems is
a fundamental and key issue in quantum information theory. In this paper, we
investigate -nonseparability and -partite entanglement of -partite
quantum systems from the perspective of the generalized Wigner-Yanase skew
information introduced by Yang .
[\href{https://doi.org/10.1103/PhysRevA.106.052401 }{Phys. Rev. A \textbf{106},
052401 (2022)}]. More specifically, we develop two different approaches in form
of inequalities to construct entanglement criteria, which are expressed in
terms of the generalized Wigner-Yanase skew information. Any violation of these
inequalities by a quantum state reveals its -nonseparability or -partite
entanglement, so these inequalities present the hierarchic classifications of
-nonseparability or -partite entanglement for all -partite quantum
states from -nonseparability to -nonseparability or from -partite
entanglement to -partite entanglement, which are more refined than
well-known ways.
It is shown that our results reveal some -nonseparability and -partite
entanglement that remain undetected by other methods, and these are illustrated
through some examples.Comment: 12 pages, 2 figure
Efficient detection for quantum states containing fewer than unentangled particles in multipartite quantum systems
In this paper, we mainly investigate the detection of quantum states
containing fewer than unentangled particles in multipartite quantum
systems. Based on calculations about operators, we derive two practical
criteria for judging -partite quantum states owning fewer than
unentangled particles. In addition, we demonstrate the effectiveness of our
frameworks through some concrete examples, and specifically point out the
quantum states having fewer than unentangled particles that our methods can
detect, while other criteria cannot recognize.Comment: 7 page
Criterion of mechanical instabilities for dislocation structures
To understand the nature of mechanical instabilities of dislocation structures, which plays a central role, for example, in determining the plastic behavior and fatigue in crystalline metals, it is essential to investigate a critical condition in which a dislocation structure collapses. A criterion for the mechanical instability of arbitrary dislocation structures is proposed in this paper. According to the criterion, the mechanical instability can be described by the positiveness of the minimum eigenvalue of the Hessian matrix, which is composed by the second-order differential of potential energy of the system with respect to the dislocation coordinates. In addition, the collapse mode can be simultaneously determined by the eigenvector of the minimum eigenvalue. We applied the proposed criterion to the veins and dislocation walls under external loading, and it successfully describes the onset of instabilities and the corresponding collapse modes, regardless of the difference in structures and sizes. This success in the criterion paves the way to address the mechanical instability issues on more complex dislocation structures
Pillar-type acoustic metasurface
International audienceWe theoretically investigate acoustic metasurfaces consisting of either a single pillar or a line of identical pillars on a thin plate, and we report on the dependence on the geometrical parameters of both the monopolar compressional and dipolar bending modes. We show that for specific dimensions of the resonators, a bending and a compressional modes may be simultaneously excited. We study their interaction with an anti-symmetric Lamb wave, whether or not they occur at the same frequency, with particular consideration for the amplitude and phase of waves emitted by the pillars at resonance. Especially, the analysis of both the amplitude and the phase of the wave at the common resonant frequency downstream a line of pillars, demonstrates that the reemitted waves allow for the transmission with phase shift of π
Duet: efficient and scalable hybriD neUral rElation undersTanding
Learned cardinality estimation methods have achieved high precision compared
to traditional methods. Among learned methods, query-driven approaches face the
data and workload drift problem for a long time. Although both query-driven and
hybrid methods are proposed to avoid this problem, even the state-of-the-art of
them suffer from high training and estimation costs, limited scalability,
instability, and long-tailed distribution problem on high cardinality and
high-dimensional tables, which seriously affects the practical application of
learned cardinality estimators. In this paper, we prove that most of these
problems are directly caused by the widely used progressive sampling. We solve
this problem by introducing predicates information into the autoregressive
model and propose Duet, a stable, efficient, and scalable hybrid method to
estimate cardinality directly without sampling or any non-differentiable
process, which can not only reduces the inference complexity from O(n) to O(1)
compared to Naru and UAE but also achieve higher accuracy on high cardinality
and high-dimensional tables. Experimental results show that Duet can achieve
all the design goals above and be much more practical and even has a lower
inference cost on CPU than that of most learned methods on GPU
Tunable waveguide and cavity in a phononic crystal plate by controlling whispering-gallery modes in hollow pillars
International audienceWe investigate the properties of a phononic crystal plate with hollow pillars and introduce the existence of whispering-gallery modes (WGMs). We show that by tuning the inner radius of the hollow pillar, these modes can merge inside both Bragg and low frequency band gaps, deserving phononic crystal and acoustic metamaterial applications. These modes can be used as narrow pass bands for which the quality factor can be greatly enhanced by the introduction of an additional cylinder between the hollow cylinder and the plate. We discuss some functionalities of these confined WGM in both Bragg and low frequency gaps for wavelength division in multiplexer devices using heteroradii pillars introduced into waveguide and cavity structures
Study on moisture re-absorption characteristics and equilibrium prediction model of coal dust with different rank
Moisture re-absorption is an effective method to measure wettability of coal dust, but for different types of coal dust, there are difference in their hydrophilicity. In order to explore the moisture re-absorption characteristics of coal dust with different degrees of coalification, the variation of moisture re-absorption rate of coal dust under different ambient temperature and relative humidity was compared and analyzed by a self-designing moisture re-absorption experimental system. The effect of coal dust properties on moisture re-absorption characteristics was clarified, and a prediction model for the moisture re-absorption equilibrium of coal dust with different degrees of coalification was established. The results showed that, with the increase of ambient temperature, the moisture re-absorption rate of coal sample firstly increased and then decreased, and the time to reach the re-absorption equilibrium was gradually shortened. In the same temperature condition, the moisture re-absorption rate of coal dust increased with increasing relative humidity, and the time to reach moisture re-absorption equilibrium was proportional to relative humidity. The higher the degree of coalification led to the stronger moisture re-absorption capacity. As the contact angle of coal dust increased, the moisture re-absorption rate was linearly inversely related to the contact angle, and the wettability of coal dust was positively linearly related to the moisture re-absorption capacity. The moisture re-absorption rate overall increased linearly with the increasing proportion of oxygen-containing functional groups. The increase of specific surface area of coal dust will inhibit the moisture re-absorption process, while the increase of pore size will promote the storage of adsorbed water, and the increase of total pore volume will provide more space for moisture re-absorption. The moisture re-absorption rate and wettability with different coalification can be effectively predicted based on the characteristic parameters of coal dust. By comparing and analyzing the fitted results of each prediction model, it was found that the Henderson model had the highest fitting degree among all the prediction models and was the most suitable for accurate prediction of moisture re-absorption equilibrium of coal dust at different coalification. The results will help to qualitatively analyze the hygroscopicity of different coal dust and provide a reference for coal dust wetting and reduction techniques
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Homozygosity Mapping and Genetic Analysis of Autosomal Recessive Retinal Dystrophies in 144 Consanguineous Pakistani Families.
PurposeThe Pakistan Punjab population has been a rich source for identifying genes causing or contributing to autosomal recessive retinal degenerations (arRD). This study was carried out to delineate the genetic architecture of arRD in the Pakistani population.MethodsThe genetic origin of arRD in a total of 144 families selected only for having consanguineous marriages and multiple members affected with arRD was examined. Of these, causative mutations had been identified in 62 families while only the locus had been identified for an additional 15. The remaining 67 families were subjected to homozygosity exclusion mapping by screening of closely flanking microsatellite markers at 180 known candidate genes/loci followed by sequencing of the candidate gene for pathogenic changes.ResultsOf these 67 families subjected to homozygosity mapping, 38 showed homozygosity for at least one of the 180 regions, and sequencing of the corresponding genes showed homozygous cosegregating mutations in 27 families. Overall, mutations were detected in approximately 61.8 % (89/144) of arRD families tested, with another 10.4% (15/144) being mapped to a locus but without a gene identified.ConclusionsThese results suggest the involvement of unmapped novel genes in the remaining 27.8% (40/144) of families. In addition, this study demonstrates that homozygosity mapping remains a powerful tool for identifying the genetic defect underlying genetically heterogeneous arRD disorders in consanguineous marriages for both research and clinical applications
Study on the Technology of Ultrasonic, Chemical and Mechanical Combined Treatment of Oilfield Aging Oil
Aging oil is a common pollutant in petrochemical enterprises due to its severe emulsification and flocculation, poor settling performance, low oil recovery rate, and high difficulty in treatment. This article adopts the method of mechanical, ultrasonic, and chemical coupling demulsification to treat aging oil, with the water content and oil recovery rate of the treated aging oil as the inspection indicators. The experiment shows that when the oil-water ratio is 1:4, the heating temperature is 50℃, the stirring speed is 180rpm, the ultrasonic frequency is 25kHz, the power is 40W, the ultrasonic time is 25min, and the pH is adjusted to 3-4. The additional amount of FeSO4 is 160mg/L, the additional amount of H2O2 is 0.11%, and the heating stirring reaction is 40min. When the dosage of cationic PAM with an ion degree of 50 is 35mg/L, the centrifugation speed is 3200rpm. The centrifugation time is 20 min, the crude oil recovery rate after aging oil treatment can reach over 94.6%, and the water content of the treated crude oil is less than 0.5%, meeting the standards for crude oil gathering and transportation in China. The oil content in the water generated after aging oil treatment is about 150 mg.L-1, the suspended solids content is 200 mg.L-1, the oil content in the residue is 6%, and the water content is 53%. By analyzing the appearance of aging oil before and after treatment, it was found that when using this process to treat aging oil, the original spatial cross-linking network structure of the aging oil was broken, allowing the water droplets wrapped in the oil to be released, thereby significantly reducing the water content in the recovered oil and improving the oil recovery rate
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