752 research outputs found

    Deep learning method in testing the cosmic distance duality relation

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    The cosmic distance duality relation (DDR) is constrained from the combination of type-Ia supernovae (SNe Ia) and strong gravitational lensing (SGL) systems using deep learning method. To make use of the full SGL data, we reconstruct the luminosity distance from SNe Ia up to the highest redshift of SGL using deep learning, then it is compared with the angular diameter distance obtained from SGL. Considering the influence of lens mass profile, we constrain the possible violation of DDR in three lens mass models. Results show that in the SIS model and EPL model, DDR is violated at high confidence level, with the violation parameter η0=−0.193−0.019+0.021\eta_0=-0.193^{+0.021}_{-0.019} and η0=−0.247−0.013+0.014\eta_0=-0.247^{+0.014}_{-0.013}, respectively. In the PL model, however, DDR is verified within 1σ\sigma confidence level, with the violation parameter η0=−0.014−0.045+0.053\eta_0=-0.014^{+0.053}_{-0.045}. Our results demonstrate that the constraints on DDR strongly depend on the lens mass models. Given a specific lens mass model, DDR can be constrained at a precision of O(10−2)\textit{O}(10^{-2}) using deep learning.Comment: 11 pages,4 figure

    Crystallization and Preliminary X-Ray Analysis of Human Muscle Creatine Kinase

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    This is the publisher's version, also available electronically from "http://scripts.iucr.org".Creatine kinase is a key enzyme in the energy homeostasis of cells and tissues with high and fluctuating energy demands. Human muscle MM creatine kinase is a dimeric protein with a molecular weight of \sim43 kDa for each subunit. It has been crystallized by the hanging-drop vapor-diffusion method using 2-methyl-2,4-pentanediol as precipitant. The crystals belong to the enantiomorphous space group P6_222 or P6_422 with cell parameters of a=b=89.11 and c=403.97 Ã…. The asymmetric unit of the crystal contains two subunits. A data set at 3.3 Ã… resolution has been collected using synchrotron radiation

    The Pantheon+ supernovae are consistent with a large-scale isotropic universe

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    We investigate the possible anisotropy of the universe using the most up-to-date type Ia supernovae, i.e. the Pantheon+ compilation. We fit the full Pantheon+ data with the dipole-modulated Λ\LambdaCDM model, and find that it is well consistent with a null dipole. We further divide the full sample into several subsamples with different high-redshift cutoff zcz_c. It is shown that the dipole appears at 2σ2\sigma confidence level only if zc≤0.1z_c\leq 0.1, and in this redshift region the dipole is very stable, almost independent of the specific value of zcz_c. For zc=0.1z_c=0.1, the dipole amplitude is D=1.0−0.4+0.4×10−3D=1.0_{-0.4}^{+0.4}\times 10^{-3}, pointing towards $(l,b)=(334.5_{\ -21.6^{\circ}}^{\circ +25.7^{\circ}},16.0_{\ -16.8^{\circ}}^{\circ +27.1^{\circ}}),whichisabout, which is about 65^{\circ}$ away from the CMB dipole. This implies that the full Pantheon+ is consistent with a large-scale isotropic universe, but the low-redshift anisotropy couldn't be purely explained by the peculiar motion of the local universe.Comment: 11 pages, 6 figure

    Crystal structure of human muscle creatine kinase

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    This is the publisher's version, also available electronically from "http://scripts.iucr.org".The crystal structure of human muscle creatine kinase has been determined by the molecular-replacement method and refined at 3.5 Ã… resolution. The structures of both the monomer and the dimer closely resemble those of the other known structures in the creatine kinase family. Two types of dimers, one with a non-crystallographic twofold symmetry axis and the other with a crystallographic twofold symmetry axis, were found to occur simultaneously in the crystal. These dimers form an infinite `double-helix'-like structure along an unusual long crystallographic 31 axis

    Study of an Improved Fuzzy Direct Torque Control of Induction Motor

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    The conventional direct torque control will inevitably produce torque ripple because of its way of flux estimates. For the purpose of handling this problem, a new control strategy was presented in this paper. This strategy combined subdivides control with voltage vector and fuzzy logic control in traditional direct torque control. In this model, the fuzzy logic combined the phase angle of the flux, the flux error and torque error as fuzzy variables and classified these fuzzy variables, in order to optimize the choice of voltage space vector, and the same time the traditional PID regulator is replaced by a fuzzy regulator. Simulation results show that, a great improvement torque responses , a great reduction of torque ripples is achieved and the strategy has a better dynamic and steady performance, especially in low-speed area

    Exploring Boarding Strategies for High-Speed Railway

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    In light of the increasing demand for passenger transportation on high-speed railway (HSR), the pedestrian flow at HSR stations has become quite crowded in many countries, which has attracted researchers to study the HSR boarding behavior. In this paper, we propose three boarding strategies based on the features of the boarding behavior at an origin HSR station; we then use a cellular automaton (CA) model to study the impacts of boarding strategies on each passenger’s motion during the boarding process at HSR station. The simulation results indicate that some of the three strategies can optimize some passengers’ boarding time and relieve the congestion degree, and the positive impacts on the boarding process are the most prominent when the three strategies are used simultaneously. The results can help administrators to effectively organize the boarding process at the origin HSR station

    Uniform design for the optimization of Al2O3 nanofilms produced by electrophoretic deposition

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    Surface modification by means of nanostructures is of interest to enhance boiling heat transfer in various applications including the organic Rankine cycle (ORC). With the goal of obtaining rough and dense aluminum oxide (Al2O3) nanofilms, the optimal combination of process parameters for electrophoretic deposition (EPD) based on the uniform design (UD) method is explored in this paper. The detailed procedures for the EPD process and UD method are presented. Four main influencing conditions controlling the EPD process were identified as nanofluid concentration, deposition time, applied voltage and suspension pH. A series of tests were carried out based on the UD experimental design. A regression model and statistical analysis were applied to the results. Sensitivity analyses of the effect of the four main parameters on the roughness and deposited mass of Al2O3 films were also carried out. The results showed that Al2O3 nanofilms were deposited compactly and uniformly on the substrate. Within the range of the experiments, the preferred combination of process parameters was determined to be nanofluid concentration of 2 wt.%, deposition time of 15 min, applied voltage of 23 V and suspension pH of 3, yielding roughness and deposited mass of 520.9 nm and 161.6 × 10− 4 g/cm2, respectively. A verification experiment was carried out at these conditions and gave values of roughness and deposited mass within 8% error of the expected ones as determined from the UD approach. It is concluded that uniform design is useful for the optimization of electrophoretic deposition requiring only 7 tests compared to 49 using the orthogonal design method
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