•The Ga-In eutectic melting plateau was realized for the first time for more than 80 h with the temperature change<1.5 mK.•The inflection point manner shows the best performance, and is recommend for ...Ga-In eutectic melting point determination.•The phase transition point temperature was determined to be (15.6479 ± 0.0009) °C, with reproducibility of less than 0.14 mK.
In this paper, the experimental results for binary alloys of gallium with indium melting plateau realization are reported. The Ga-In eutectic plateaus can last for more than 80 h with a temperature change of less than 1.5 mK. Various methods were employed to accurately determine the phase transition point of the Ga-In eutectic. By calculation, the point of inflection (POI) manner shows the best performance and is recommended for the determination of the Ga-In eutectic phase transition point. By repeatedly realising Ga-In eutectic melting plateaus, the melting point temperature was determined to be 15.6479 °C, with a reproducibility of less than 0.14 mK. The corresponding realization uncertainty of Ga-In eutectic was also analyzed and was found to be 0.90 mK (k = 2). These results are consistent with those of previous studies within the associated uncertainties and will help better understand the phase diagram and the corresponding thermal properties of the Ga-In eutectic.
Abstract Quantum phase transitions with multicritical points are fascinating phenomena occurring in interacting quantum many-body systems. However, multicritical points predicted by theory have been ...rarely verified experimentally; finding multicritical points with specific behaviors and realizing their control remains a challenging topic. Here, we propose a system that a quantized light field interacts with a two-level atomic ensemble coupled by microwave fields in optical cavities, which is described by a generalized Dicke model. Multicritical points for the superradiant quantum phase transition are shown to occur. We determine the number and position of these critical points and demonstrate that they can be effectively manipulated through the tuning of system parameters. Particularly, we find that the quantum critical points can evolve into a Lifshitz point (LP) if the Rabi frequency of the light field is modulated periodically in time. Remarkably, the texture of atomic pseudo-spins can be used to characterize the quantum critical behaviors of the system. The magnetic orders of the three phases around the LP, represented by the atomic pseudo-spins, are similar to those of an axial next-nearest-neighboring Ising model. The results reported here are beneficial for unveiling intriguing physics of quantum phase transitions and pave the way towards to find novel quantum multicritical phenomena based on the generalized Dicke model.
Interior Point Methods for Linear Optimization is a comprehensive, thorough textbook on interior point methods (IPMs). The era of IPMs was initiated by N. Karmarkar's 1984 paper, which triggered ...turbulent research and reshaped almost all areas of optimization theory and computational practice. This book gives a comprehensive review of the main results of more than a decade of IPM research. Numerous exercises are provided to aid in understanding the material.
In this paper, an iterative algorithm is introduced to solve the split common fixed point problem for asymptotically nonexpansive mappings in Hilbert spaces. The iterative algorithm presented in this ...paper is shown to possess strong convergence for the split common fixed point problem of asymptotically nonexpansive mappings although the mappings do not have semi-compactness. Our results improve and develop previous methods for solving the split common fixed point problem. MSC: 47H09, 47J25.
The dense matching of pairs is the basis of advanced image processing applications, such as 3D reconstruction and simultaneous localisation and mapping (SLAM). However, it is difficult to obtain ...efficient dense matching results in wide baseline image pairs due to various conditions. For this reason, the authors propose a dense matching method for wide baseline images based on an equal proportion of triangulation. Firstly, this Letter proves the mathematical property of equal proportion of triangulation affine transformation, and then builds a triangulation based on the set of sparse matching points. By using this property, the positions of equal proportion points in the corresponding triangulation of the two images to be matched are calculated, respectively. Secondly, to eliminate the points and obtain the inner point set, these proportional points are used to check the similarity of the matching triangle regions. Finally, the inner point set is used to calculate the positions of the dense matching points as the final dense matching result. The experimental results verified the validity and accuracy of the proposed method and this method is suitable for tilt photography, multispectral and multidate remote sensing image dense registration, and more.
One of unsolved puzzles about water lies in how ion-water interplay affects its freezing point. Here, we report the direct link between tetrahedral entropy and the freezing behavior of water in Zn
...-based electrolytes by analyzing experimental spectra and molecular simulation results. A higher tetrahedral entropy leads to lower freezing point, and the freezing temperature is directly related to the entropy value. By tailoring the entropy of water using different anions, we develop an ultralow temperature aqueous polyaniline| |Zn battery that exhibits a high capacity (74.17 mAh g
) at 1 A g
and -80 °C with ~85% capacity retention after 1200 cycles due to the high electrolyte ionic conductivity (1.12 mS cm
). Moreover, an improved cycling life is achieved with ~100% capacity retention after 5000 cycles at -70 °C. The fabricated battery delivers appreciably enhanced performance in terms of frost resistance and stability. This work serves to provide guidance for the design of ultralow temperature aqueous batteries by precisely tuning the water structure within electrolytes.
Metals usually exist in the form of polycrystalline solids, which are thermodynamically unstable because of the presence of disordered grain boundaries. Grain boundaries tend to be eliminated through ...coarsening when heated or by transforming into metastable amorphous states when the grains are small enough. Through experiments and molecular dynamics simulations, we discovered a different type of metastable state for extremely fine-grained polycrystalline pure copper. After we reduced grain sizes to a few nanometers with straining, the grain boundaries in the polycrystals evolved into three-dimensional minimal-interface structures constrained by twin boundary networks. This polycrystalline structure that underlies what we call a Schwarz crystal is stable against grain coarsening, even when close to the equilibrium melting point. The polycrystalline samples also exhibit a strength in the vicinity of the theoretical value.
Review of drop impact on heated walls Liang, Gangtao; Mudawar, Issam
International journal of heat and mass transfer,
March 2017, 2017-03-00, 20170301, Letnik:
106
Journal Article
Recenzirano
•Drop impact is reviewed in terms of heat transfer mechanisms and predictive tools.•It is segregated into film evaporation, nucleate, transition and film boiling.•Inconsistencies are found regarding ...impact process and ensuing heat transfer.•Recommendations are provided for future research.
This paper provides a comprehensive review of published literatures concerning the fluid mechanics and heat transfer mechanisms of liquid drop impact on a heated wall. The review is divided into four parts, each centered on one of the main heat transfer regimes: film evaporation, nucleate boiling, transition boiling, and film boiling. Each of these regimes is discussed in detail in terms of available depictions of drop deformation and/or breakup, proposed heat transfer mechanisms, predictive correlations and/or models. It is shown that understanding the underlying physics for each heat transfer regime is highly dependent on the experimental methods that investigators have adopted, and broadness of available databases in terms of liquid type, drop size and momentum, impact angle, and wall material and surface roughness. Despite significant advances in experimental, theoretical and computational research in understanding the interfacial behavior of the drop from the moment of impact, there are many inconsistencies concerning some of the most important aspects of the impact process and ensuing heat transfer, especially in regards to critical heat flux, transition boiling, and the Leidenfrost point. This review is concluded with recommendations concerning future work that is needed to address poorly understood and/or contradictory issues.
•The physical properties of the bio-jet fuel can be adjusted by controlling the CC coupling conditions.•The alkane with spiro ring structure has the low freezing point.•W/O microemulsion formed by ...the NaOH solution and cyclohexane favors the aldol condensation.•The density of the jet fuel is 0.869 g·ml−1 and the freezing point is lower than −60℃.
Production of jet fuel with high performance is attractive in the field of biomass utilization. This paper provides a way to controllably produce renewable jet fuel with high-density and low-freezing point by the condensation of biomass-derived cyclopentanone and followed hydrodeoxygenation. It is found that the freezing point of the jet fuel decreased rapidly with the increase of the content of spirocyclic alkane and the density increased gradually with content of tricyclic alkane. And the composition of jet fuel can be adjusted by controlling the reaction conditions of cyclopentanone condensation. At 30 °C and 3 h, the precursors of jet fuel were prepared by condensation of cyclopentanone over NaOH catalyst and the final obtained HDO products were comprised of 54.56% bicyclopentane, 31.88% tricyclic alkane and 13.56% spirocyclic alkane. The density of the jet fuel was 0.869 g·ml−1 and the freezing point was less than −60 °C. These parameters are obviously superior to that of commercial Jet-A.
Conductive fibers have received considerable interest due to their potential applications in the flexible electronics field. Fabricating a conductive fiber that can realize fast deformation with ...stretchability for multifunctional applications is still highly appealing. Here, we present a deformable conductive fiber (DCF) fabricated by injecting liquid metal (LM) into a hollow thermoplastic polyurethane (TPU) fiber; the DCF can be shaped into a 2D or 3D shape by an electrothermal method at the thermoplastic transition point of TPU. Combined with the solid-liquid phase transition characteristics of the LM at its melting point, the DCF exhibits a variable shape memory feature at two transition points. We have demonstrated that the double-torsional DCF and the helical DCF can act as a capacitive sensor and an inductive sensor, respectively, and they have both been used for human motion monitoring. In addition, the helical DCF can also act as a stretchable electrode with excellent electrical properties (resistance change <2%) under a maximal mechanical strain of 3300%. Overall, the DCF presents great potential for applications in human motion monitoring, soft robotics and smart electronic textiles.
We present a deformable conductive fiber composed of a hollow TPU fiber filled with liquid metal, which can realize fast shape transformation by electrothermal heating, for multifunctional applications.
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