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As one of the most promising critical technologies for realizing 5G networks, mmWave communication technology has received more and more attention and research. At the same time, due to the integration and symbiosis of mmWave communication, massive MIMO, and ultra-dense network, recent organizations have also jointly proposed the rational introduction of these three technologies in mobile communication systems to improve spectrum efficiency and energy efficiency in 5G. This paper focuses on a single-cell multi-user mmWave massive MIMO system. To optimize the total data rate, we propose a beam allocation algorithm based on a one-to-one matching game under the condition that the number of RF chains is less than the number of users. The simulation results show that the proposed algorithm obtains almost the same performance as the exhaustive method on the premise that the algorithm complexity is lower than the thorough method.

The spherically convergent plasma fusion (SCPF) scheme is a robust approach to provide a high-brightness pulsed neutron source. The performance of the SCPF driven by the long-pulsed laser is investigated. The experiments, with the laser pulse duration in a range of 0.5 ns to 3 ns, were implemented on the ShenGuang-II Upgrade facility and a 100 kJ level laser facility. The intensity of the laser beam was about multiple 1014 W cm−2. The measured D–D reaction neutron yields were in a range of 7.3 × 108 to 1.01 × 1011, while the driven laser energies were in a range of 2.1 kJ to 100.5 kJ. The temporal self-emitted x-ray flux and image were measured. It showed that the plasma core could be maintained for a longer time in the long duration shots. The neutron reaction rate was measured on the 100 kJ level laser facility. The full width at half maximum reached about 1 ns in the shot with 2 ns duration laser. The scaling law of the measured yields with respect to the laser power and the pulse duration were presented. The neutron yield was able to be increased by increasing the power and extending the duration.

In view of the complex stability calculation of double-row steel sheet piles in soft soil foundation, based on the theory of soil mechanics, the control analysis was carried out from the aspects of anti-uplift stability, overall anti-slip stability, anti-overturning stability, and overall sliding stability of the sheet pile. By theoretical derivation and calculation, the calculation formula of the minimum penetration depth Ld of steel sheet piles is given. Taking the double-row steel sheet pile cofferdam project of the sluice of the Oufei Reclamation Project in Zhejiang Province of China as a case, according to the formula in this paper, the recommended minimum depth of soil penetration is 17.01m, which is basically the same as the actual design value of 18.50m. Combined with the finite element soft foundation, the comparative analysis of simulation calculation results and the measured horizontal displacement monitoring data of steel sheet piles provides references for related engineering applications.

This study experimentally examined the flow phenomena and pressure distribution on the wing of Advisory Group for Aerospace Research and Development Model B (AGARD-B) at a Mach number of 0.83. For simultaneous pressure and temperature measurement, a mesoporous pressure-sensitive paint (PSP) sensor was applied to one of the wings of AGARD-B at an angle of attack (AOA) of 0°–8° and a temperature-sensitive paint sensor was applied to the other wing. The collected temperature data were used for pixel-by-pixel temperature correction in a PSP experiment. The pressure distribution obtained on the AGARD-B wing through the PSP experiment with temperature correction agreed well with that obtained through computational flow dynamics (CFD) simulation and accurately indicated the low-pressure regions introduced by the vortex generated from the leading edge at an AOA larger than 4°. The lift coefficient calculated using the PSP data agreed well with that calculated using CFD.

The promotion of the level of social urbanization puts forward higher requirements for the functionality of the city, and it is the most important auxiliary for the city function to play and reflect. The utilization of PPGIS in urban-rural schematization incalculably accelerates the improvement and development of urban-rural schematization level. Based on this, this paper first analyses the connotation, typical features and functions of PPGIS, then studies the utilization of PPGIS in urban-rural schematization, and finally gives the utilization strategies of PPGIS and network info tech in urban-rural schematization.

At present, the classification system of urban and rural planning land still lacks the division of land functions, especially the in-depth study of land data conversion, which leads to the lack of effective use of land spatial classification data and the failure to establish effective classification system criteria. Based on this, this paper first analyses the construction of urban-rural planning land classification system and land type conversion convergence criteria, then studies the land type recognition based on multi-source data of IoT, and finally gives the optimization strategy of urban-rural planning land classification recognition based on multi-source data of IoT.

OpenFOAM is a free, open-source software package that can be used for the solutions of computational fluid dynamics and simulation of various fluid flow processes. Nevertheless, OpenFOAM still lacks default settings and a large number of different numerical schemes and turbulent models should be validated. In this paper, the unsteady flow around a cylinder (Re=3900) is calculated by the large eddy simulation of OpenFOAM. The predictions include the drag and lift coefficient, the pressure distribution around the cylinder, the velocity distribution and Reynolds stress distribution in the wake region, as well as the prediction of the recirculation length and separation angle. Thanks to several simulations, these five subgrid-scale (SGS) models are compared and studied: The Smagorinsky SGS model, wall adaptive local eddy visibility SGS model, dynamic SGS model with Lagrangian averaging, dynamic one equation eddy visibility model, one equation eddy visibility model. The numerical results are verified with the published experimental data.

The influence of low-mode-driven asymmetry on yield degradation in shaped-pulse indirect-drive implosions has been investigated at the 100 kJ laser facility. In this work, P2- and P4-driven asymmetries were tuned by varying hohlraum gas-fill density and capsule diameter. The measured neutron yield varied from 2.1 × 109 to 7.6 × 109 and the yield measured by a 1D simulation (YOC1D) was increased from 3% to 16%. Meanwhile, considering the temporal P2- and P4-driven asymmetries, the yields measured by 2D simulations (YOC2D) were from 26% to 81% (the YOC2D of the majority of the shots was higher than 50%). Furthermore, both the ion temperature and neutron bang-time showed good agreement between the measurements and the 2D simulations. The simulations demonstrated that the temporal P2- and P4-driven asymmetries can decrease the efficiency of PdV work and increase the energy loss due to electron thermal conduction. In addition, the internal energy of the deuterium (DD) fuel clearly decreased and the neutron yield was degraded by low-mode asymmetry. In a future work, we will enlarge the cylindrical hohlraum diameter or use an I-hohlraum to improve the low-mode-driven symmetry, along with measurement of the hot-spot shape.

Clustering is one of the important techniques for pattern recognition. Traditional clustering methods often group data objects by distance measurement. However, it is difficult to measure data in high-dimensional space. This paper proposes a clustering method for high-dimensional data. It combines the information theory criteria to establish clustering rules. The improved of K-Means is used to generate basis clustering, then the clustering ensemble is used to integrate the initial clusters to obtain a more stable final result. Our proposed method is tested on standard datasets, and its performance is compared with K-means ensemble. The experimental results indicate effectiveness for high-dimensional data clustering.

Vertically stacked devices of two-dimensional layered materials (2DLMs) based on van der Waals heterostructures (vdWHs) have recently attracted considerable attention due to their good properties. A tunneling structure is presented in this paper that, unlike other tunneling structures, has no specific insulating two-dimensional materials, such as boron nitride. The tunneling structure is comprised of graphene and black phosphorus. Black phosphorus is chemically active, and can be easily oxidized in the air to form an insulating layer. A tunneling device was produced based on this characteristic of black phosphorus. The insulation layer was an oxide layer formed by the oxidation of black phosphorus. The structure takes advantage of the easy oxidation ability of black phosphorus. The presence of a black phosphorus oxide layer was determined by XPS analysis. The tunneling characteristics of the overlay structure were determined by measuring the current-voltage (Id-V) curve of the device. Simulation studies showed that the oxidation layer was responsible for the tunneling effect. Compared with other black phosphorus devices, the photoelectric properties of the proposed device were greatly improved.

The washing and elution behaviour of carbon nanotubes (CNTs), following soaking in radioactive (I-125)NaI and (Ag-110m)AgNO3 solutions, was investigated using the radioactive-trace technique. High-resolution electron microscopy and x-ray energy dispersive spectroscopy observations showed the validity of filling CNTs with soluble inorganic salts using this simple method. A great difference in the release of (I-125)NaI and (Ag-110m)AgNO3 from CNTs was found and discussed in terms of the chemical transformation occurring in CNT cavities. The amount of the filled materials was also estimated using the radioactive-trace technique.

Radiation-induced defect annealing in He+ ion-implanted 4H-SiC via H+ ion irradiation is investigated by Raman spectroscopy. There are 4H-SiC wafers irradiated with 230 keV He+ ions with fluences ranging from 5.0x10(15) cm(-2) to 2.0 x 10(16) cm(-2) at room temperature. The post-implantation samples are irradiated by 260 keV H+ ions at a fluence of 5.0 x 10(15) cm(-2) at room temperature. The intensities of Raman lines decrease after He implantation, while they increase after H irradiation. The experimental results present that the magnitude of Raman line increment is related to the concentration of pre-existing defects formed by He implantation. A strong new peak located near 966 cm(-1), which is assigned to 3C-SiC LO (Gamma) phonon, is found in the He-implanted sample with a fluence of 5.0 x 10(15) cm(-2) followed by H irradiation. However, for the He-implanted sample with a fluence of 2.0 x 10(16) cm(-2) followed by H irradiation, no 3C-SiC phonon vibrations are found. The detailed reason for H irradiation-induced phase transformation in the He-implanted 4H-SiC is discussed.

Electron emission from ferroelectric cathode (FEE) is unconventional electron emission effect. Experimental studies on ferroelectric emission (properties of PLZST antiferroelectric ceramics samples) at room temperature and in low vacuum had been carried out. Both islands electrode and stripes electrode were used in experiments. The influences of front electrode patterns on electron emission were investigated by measuring the emission current from the sample. It had been found that different patterned front electrodes yielded different emission current. The islands electrode emitted lower current than the stripes electrode.