bluuebunny/crossref_metadata_2025_split huggingface dataset:
Isotope effects on transport in LHD
Authors: Tanaka K , Nagaoka K , Ida K , Yamada H , Kobayashi T , Satake S , Nakata M , Kinoshita T , Ohtani Y , Tokuzawa T , Takahashi H , Warmer F , Mukai K , Murakami S , Sakamoto R , Nakano H , Osakabe M , Morisaki T , Nunami M , Tala T , Tsujimura T , Takemura Y , Yokoyama M , Seki R , Igami H , Yoshimura Y , Kubo S , Shimozuma T , Akiyama T , Yamada I , Yasuhara R , Funaba H , Yoshinuma M , Goto M , Oishi T , Morita S , Motojima G , Shoji M , Masuzaki S , Michael C A , Vacheslavov L N 
Published: July 2021

Abstract
Isotope effects are one of the most important issues for predicting future reactor operations. Large helical device (LHD) is the presently working largest stellarator/helical device using super conducting helical coils. In LHD, deuterium experiments started in 2017. Extensive studies regarding isotope effects on transport have been carried out. In this paper, the results of isotope effect studies in LHD are reported. The systematic studies were performed adjusting operational parameters and nondimensional parameters. In L mode like normal confinement plasma, where internal and edge transport barriers are not formed, the scaling of global energy confinement time (τ
E) with operational parameters shows positive mass dependence (M
0.27; where M is effective ion mass) in electron cyclotron heating plasma and no mass dependence (M
0.0) in neutral beam injection heating plasma. The non-negative ion mass dependence is anti-gyro-Bohm scaling. The role of the turbulence in isotope effects was also found by turbulence measurements and gyrokinetic simulation. Better accessibility to electron and ion internal transport barrier (ITB) plasma is found in deuterium (D) plasma than in hydrogen (H). Gyro kinetic non-linear simulation shows reduced ion heat flux due to the larger generation of zonal flow in deuterium plasma. Peaked carbon density profile plays a prominent role in reducing ion energy transport in ITB plasma. This is evident only in plasma with deuterium ions. New findings on the mixing and non-mixing states of D and H particle transports are reported. In the mixing state, ion particle diffusivities are higher than electron particle diffusivities and D and H ion density profiles are almost identical. In the non-mixing state, ion particle diffusivity is much lower than electron diffusivity. Deuterium and hydrogen ion profiles are clearly different. Different turbulence structures were found in the mixing and non-mixing states suggesting different turbulence modes play a role.
Physical aspects of anisotropic compact stars in

gravity with off diagonal tetrad
Authors: Zubair M. , Ditta Allah , Abbas G. , Saleem Rabia 
Published: July 2021

Abstract
This study addresses the formation of anisotropic compact star models in the background of

gravity (where T and

represent the torsion and trace of the energy momentum tensor, respectively).

gravity is an extension of the

theory, and it allows a general non-minimal coupling between T and

. In this setup, we apply Krori and Barua's solution to the static spacetime with the components

and

. To develop viable solutions, we select a well-known model

(where αand β are coupling parameters, and ϕ indicates the cosmological constant). We adopt the conventional matching of interior and exterior space time to evaluate the unknowns, which are employed in the stellar configuration. We present a comprehensive discussion on the stellar properties to elaborate the anisotropic nature of compact stars corresponding to well-known models:

,

,

,

, and

. Via physical analysis, it is observed that the solution of compact spheres satisfy the acceptability criteria, and its models behave optimally and depict stability and consistency, in accordance with

gravity.
Ultraviolet communication technique and its application
Authors: Guo Liang , Guo Yanan , Wang Junxi , Wei Tongbo 
Published: July 2021

Abstract
With recent developments of deep ultraviolet (DUV) light-emitting diodes and solar-blind detectors, UV communication (UVC) shows great potential in replacing traditional wireless communication in more and more scenarios. Based on the atmospheric scattering of UV radiation, UVC has gained considerable attention due to its non-line-of-sight ability, omnidirectional communication links and low background noise. These advantages make UVC an ideal option for covert secure communication, especially for military communication. In this review, we present the history and working principle of UVC with a special focus on its light sources and detectors. Comprehensive comparison and application of its light sources and detectors are provided to the best of our knowledge. We further discuss the future application and outlook of UVC. Hopefully, this review will offer valuable insights into the future development of UVC.
First-principles study of the growth and diffusion of B and N atoms on the sapphire surface with h-BN as the buffer layer
Authors: Zhao Jianyun , Li Xu , Liu Ting , Lu Yong , Zhang Jicai 
Published: July 2021

Abstract
Currently, the preparation of large-size and high-quality hexagonal boron nitride is still an urgent problem. In this study, we investigated the growth and diffusion of boron and nitrogen atoms on the sapphire/h-BN buffer layer by first-principles calculations based on density functional theory. The surface of the single buffer layer provides several metastable adsorption sites for free B and N atoms due to exothermic reaction. The adsorption sites at the ideal growth point for B atoms have the lowest adsorption energy, but the N atoms are easily trapped by the N atoms on the surface to form N–N bonds. With the increasing buffer layers, the adsorption process of free atoms on the surface changes from exothermic to endothermic. The diffusion rate of B atoms is much higher than that of the N atoms thus the B atoms play a major role in the formation of B–N bonds. The introduction of buffer layers can effectively shield the negative effect of sapphire on the formation of B–N bonds. This makes the crystal growth on the buffer layer tends to two-dimensional growth, beneficial to the uniform distribution of B and N atoms. These findings provide an effective reference for the h-BN growth.
Impact of switching frequencies on the TID response of SiC power MOSFETs
Authors: Yang Sheng , Liang Xiaowen , Cui Jiangwei , Zheng Qiwen , Sun Jing , Liu Mohan , Zhang Dang , Feng Haonan , Yu Xuefeng , Xiang Chuanfeng , Li Yudong , Guo Qi 
Published: July 2021

Abstract
Different switching frequencies are required when SiC metal–oxide–semiconductor field-effect transistors (MOSFETs) are switching in a space environment. In this study, the total ionizing dose (TID) responses of SiC power MOSFETs are investigated under different switching frequencies from 1 kHz to 10 MHz. A significant shift was observed in the threshold voltage as the frequency increased, which resulted in premature failure of the drain–source breakdown voltage and drain–source leakage current. The degradation is attributed to the high activation and low recovery rates of traps at high frequencies. The results of this study suggest that a targeted TID irradiation test evaluation method can be developed according to the actual switching frequency of SiC power MOSFETs.
Reliability evaluation on sense-switch p-channel flash
Authors: Song Side , Liu Guozhu , Zhang Hailiang , Chao Lichao , Wei Jinghe , Zhao Wei , Hong Genshen , He Qi 
Published: July 2021

Abstract
In this paper, the reliability of sense-switch p-channel flash is evaluated extensively. The endurance result indicates that the p-channel flash could be programmed and erased for more than 10 000 cycles; the room temperature read stress shows negligible influence on the p-channel flash cell; high temperature data retention at 150 °C is extrapolated to be about 5 years and 53 years corresponding to 30% and 40% degradation in the drive current, respectively. Moreover, the electrical parameters of the p-channel flash at different operation temperature are found to be less affected. All the results above indicate that the sense-switch p-channel flash is suitable to be used as the configuration cell in flash-based FPGA.
X-band monolithic three-stage LNA with GaAs E-mode PHEMT
Authors: Zuo Zhengxing , Sun Shufeng 
Published: July 2021

Abstract
An LNA for 8∼12 GHz is proposed in this paper. The amplifier uses a GaAs process with cost-effective, E-mode HEMTs with gate widths of 0.25 µm and 0.45 µm. The three stages of the LNA are powered by dual power supplies, with a drain operating voltage of +3V and a gate operating voltage of +0.7V. The simulation results of the schematic diagram show that the noise factor of the low-noise amplifier is less than 2.5dB in the frequency range of 8-12GHz, the in-band gain is greater than 30dB, the gain flatness is ±1.5dB, the 1dB compression point is 7dbm, the VSWRs are less than -10dB, and the LNA is absolutely stable in the X-band.
A line spectrum detector based on improved coherent power spectrum estimation
Authors: Feng Song , Jiang Keyu , Kong Xiaopeng 
Published: July 2021

Abstract
The line spectrum detection method based on coherent power spectrum estimation is one of the important research directions of weak signal line spectrum detection. For the purpose of resolving the problem of phase compensation inaccurate introduced by limited frequency search accuracy with the existing coherent power spectral estimate method, a modified line spectrum detector is proposed. The zero padding is used to improve the line spectrum frequency search accuracy in discrete Fourier transform (DFT) for phase compensation calculations, thereby obtaining more accurate line spectrum frequencies and phase compensation, which further improves Line spectrum detection performance. The detection performances of three detections based on Welch’s method, coherently averaged power spectral estimate(CAPSE) and modified method are compared each other by computer simulations. The results show modified line spectrum detection can obtain a gain of 2-3dB, which verifies the effectiveness of the modified method.
Design of multi-channel digital correlator in SAMR
Authors: Ma Xiaoqing , Sun Baohua , Liu Jie , Ren Hongxuan , Jiang Tong 
Published: July 2021

Abstract
Synthetic Aperture Microwave Radiometer (SAMR) can be carried on the satellite to realize the global large-scale measurement of ocean salinity and soil moisture. As a key component of SAMR, the multi-channel digital correlator has been introduced in this paper from three aspects: an improved method to implement multi-channel correlation, the correlator design and the test results of the correlator. The improved method which effectively reduces the FPGA resource utilization and system complexity is applied to the multi-channel digital correlator system which consists of three signal collectors and one signal processor. The design of multi-channel digital correlator can ensure the real-time signal sampling and processing of 144 ADC channels. The results demonstrate that the measurement accuracy of correlation coefficient can exceed 0.99.
Optimal Design of Antenna for Spaceborne SAR Based on Differential Evolution Algorithm
Authors: Zhang Xingang , Shi Zhengxin , Gao Men 
Published: July 2021

Abstract
An important feature of future spaceborne synthetic aperture radar (SAR) is the adoption of large mesh reflectors fed by arrays. The main advantage of this SAR sensor is the provision of large antenna apertures and reconfigurable feed excitation. A large deployable mesh-reflector antennas combinaed with feed arrays is designed for the application of spaceborne SAR on geosynchronous orbit. To decrease the transmit power of feed element and increase the flexibility, a large scale of two-dimensional feedarray is adopted. An approach based on defocused reflector is used to broaden the beams from feed element, so almost all the feed elements can participate in the pattern synthesis in the complete angular domain. This paper presents a new optimization method of the defocused reflector system. The method aims at getting high gain and low sidebobes by optimizing the reflector parameters together with the feed array. The differential evolution algorithm(DE) is used to get globally optimal solution. The performance of the reflector after optimization is computed to demonstrate the effective of the method presented.
Electro-thermal Coupling Model for Radial Temperature and Electric Field Distribution Computation and Experimental Research of 550kV RIP AC Oil-gas Bushings
Authors: Shiling Zhang , Wei Song , Huaxia Yang 
Published: July 2021

Abstract
The condenser of 550kV RIP oil-gas bushings is in the solid structure of resin-epoxy impregnated paper(RIP), which has large difference with the oil-immersed one (OIP). Oil-gas bushings has compact configuration and heat conduction condition is harsh, while temperature distribution has direct relationship with bushings’ long-term stable operation performance, so it’s essential to carry out research in radial temperature within condenser during production of RIP oil-gas bushing prototype. In this paper, radial temperature distribution principle of bushing condenser under linear material conditions has been summarized by building electrothermal coupling theoretical model of bushing condenser. The model has been generalized by electro-thermal coupling finite element mode under nonlinear material conditions, and electrothermal coupling iterative computation process has also been proposed, then experimental measurement study in local temperature points of bushing condenser has been carried out. The study shows that plate model has advantages of high accuracy and simple form in calculating radial temperature distribution of bushing condenser; the hot-spot temperature of 550kV RIP oil-gas bushings is about 95°C which appears near the center conductor; radial temperature of bushings under nonlinear material conditions is lower than that under linear material conditions and the thermal breakdown voltage of condenser under rated current is 538kV which is higher than the maximum operation phase voltage. This paper provides theoretical foundation for radial temperature computation within RIP bushing condenser and has some reference value for the design of HVAC RIP bushings.
Study on the damage effect of optical detector irradiated by CW laser
Authors: Zhang Peng , Zhang Zhening 
Published: July 2021

Abstract
In order to study the damage effect of continuous laser on optical detectors, an equivalent experimental method of laser irradiated optical detectors was designed and constructed in the laboratory. The damage mechanism and phenomenon of the laser are analyzed through experiments, and the power density of the laser to the target and the size of the saturated spot on the surface of the detector are measured, and the corresponding relationship between the saturation of a single pixel of the detector and the power of the laser to the target is obtained, which reveals the influence of laser power on detection The influence law of the interference characteristic of the device. The experimental results show that under the condition that the diameter of the laser beam and the distance to the target are the same, as the power of the laser to the target increases, the saturated spot size of the detector (that is, the number of saturated pixels) increases, and the saturated spot size increases with the power within the error range. The relationship is approximately linear; for a typical optical detector, the laser power at which the pixels are disturbed by saturation is a fixed value. Increasing the laser power can increase the number of saturated pixels, and the area disturbed by laser saturation is further expanded.
Optimal Design of Shaped Multiple-Beam Antenna Based on Artificial Bee Colony Algorithm
Authors: Shi Zhengxin , Zhang Xingang , Yu Fei , Gao Men 
Published: July 2021

Abstract
In order to maximize the multiple-beam performance in a specific service area, a new optimization design method of shaped single-aperture single-feed multiple-beam antenna was proposed. The contradiction between the layout of satellite platform and the performance of specific service area was solved by comprehensively optimizing the reflector and feed position. As the reflector surface and the feed position were taken as optimization variables, the objective function was constructed by the gain and XPD in the service area, and then the artificial bee colony algorithm was used for optimization, so as to obtain the optimal performance of the whole service area. Finally, an optimization design example was given, and the simulation results indicated the effectiveness of the optimization method.
Analysis and design of voltage doubling circuit for 500kV 15mA high voltage supply
Authors: Li Xiaofeng , Huang Yiyun , Rui Junhui 
Published: July 2021

Abstract
Among many important equipment and instruments, in order to obtain a stable HVDC output, a high voltage multiplier power supply is usually used. With the development of science and technology, higher requirements are put forward for the performance parameters of high voltage multiplier power supply. In this paper, the core part of the high voltage multiplier power supply - voltage doubling circuit as the focus of research. Firstly, the principle of various voltage doubling circuits are analyzed, the steady state analytical formula under ideal state is obtained and their advantages and disadvantages are analyzed. According to the above analysis and comparison, this paper proposes that the topological structure of the voltage doubling circuit for the 500kV HV power supply is the symmetrical CW multiplier circuit. Then the ripple expression of the symmetrical CW multiplier is deduced, the reason of voltage sag is analyzed, and the calculation expression is given. Finally, a simulation model of the voltage doubling circuit of the HV multiplier power supply was built in ANSYS Simplorer. The validity of the analytical design is verified by experimental simulation.
A Transformer using two RDL metal layers based on Fan-Out Panel Level Package Technology
Authors: Wang Zixu , Niu Xulei , Lin Shaopan , Lin Tingyu , Huang Guochi 
Published: July 2021

Abstract
Under the background that electronic products have been developing in the direction of being smaller, lighter and cheaper, the packaging of chip components has also been continuously improved. Fan-out panel-level package (FOPLP) is one of the latest development trends in microelectronics package, which can achieve higher productivity and lower costs. A planar toroidal spiral transformer is designed based on Fan-Out Panel Level Package technology. The transformer is constructed by two RDL layers provided by the packaging process. The size of the proposed transformer is 434um×434um. The simulated primary and secondary inductance is 2.5nH and 2.5nH respectively. The coupling factor of the transformer is 0.845. The quality factor of the transformer is higher than 800 during the entire working frequency range. The self-resonant frequency of the present transformer is 20 GHz. Compared to the on-chip counterpart, the transformer designed based on Fan-Out Panel Level Package technology can achieve higher coupling factor and quality factor. Therefore, the proposed transformer can save chip size and reduce the cost through avoiding using area hungry passive on chip transformer.
Research on control strategy and dynamic test of multi-port electric energy router
Authors: Yang Zaixin , Jian Xusheng , Ya Sitai 
Published: July 2021

Abstract
Researching an electric energy router and analyzing the control and operation characteristics are of significant importance for bi-high power system. In this study, a multi-modal two-level coordinated control strategy of multi-port electric energy router is proposed to achieve fast and flexible regulation of power flow. a prototype of multi-port energy router is trial-produced with an energy storage system, a sending-end power grid and a receiving-end power grid. Furthermore, a comprehensive dynamic test for the prototype of multi-port energy router is completed. The results show that the dynamic performance of the multi-port energy router in power step test is found to conform to the test standard. The charging and discharging modes of the energy storage unit under multi-modal control strategy are switched correctly. During the energy exchange process, multi-port AC/DC voltage operates stably. It can be applied to multi-port, multi-cascade, multi-flow distribution network.
Research on Evaluation of Port Logistics Efficiency Based on DEA-Malmquist Model
Authors: Zhang Xiaoning 
Published: July 2021

Abstract
Port logistics, as an important carrier supporting the trade exchanges of countries around the world, has a positive driving effect on economic growth. This paper adopts the DEA-Malmquist index evaluation model and takes the panel data of my country’s top ten coastal port logistics from 2012 to 2019 as the research object for empirical research. By constructing a reasonable evaluation index system, using DEA method to conduct static analysis of port logistics efficiency, and using Malmquist index method to conduct dynamic analysis of port logistics efficiency. Finally, according to the results of the logistics efficiency evaluation, targeted countermeasures and suggestions are put forward to provide reference for the improvement of my country’s port logistics efficiency.
Analysis of THz space communication link based on STK
Authors: Bai Langtao , Zhu Zhongbo , Li Xiaojun 
Published: July 2021

Abstract
The characteristics of terahertz communication technology, such as large capacity, high speed and high security, make it stand out among many wireless communication technologies. For future space communication application scenarios, the link performance and beam pointing accuracy of the terahertz communication system were analyzed. The beam adjustment angular acceleration index were analyzed through STK.
Non-continuous Orthogonal Frequency Division Multiplexing Satellite Communication Model and Analysis of Interference to Authorized System
Authors: Wang Yong , Lin Zhi , Ye Zhongfu , Wang Lei , Zhao Qingsong 
Published: July 2021

Abstract
With the aim at improving the efficiency of satellite communication spectrum utilization, this paper proposes a non-continuous orthogonal frequency division multiplexing (NC-OFDM) satellite communication model based on convolutional code and LDPC code. We further analyze the bit error rate performance of the NC-OFDM system and evaluates the interference of the authorized system. Simulation experiment results show that NC-OFDM model can significantly improve the spectrum utilization of satellite communication, which can achieve spectrum compatibility with authorized users by adopting adaptive channel access and spectrum sensing technologies.
Analysis on the Development of Radio and Television 5G IoT
Authors: Zou Feng , Shi Yuhai , Gong Yuanjia 
Published: July 2021

Abstract
This paper introduces the technical characteristics and end-to-end typical application systems of NB-IoT, puts forward the overall network architecture of NB-IoT. Based on the development status of the industry, the network deployment scheme and relevant development suggestions are proposed, providing reference for the innovative development and commercial implementation of 5G IoT in radio and television industry.