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HF Communications: Past, Present, and Future

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China Communications 2018年第9期15卷 1-9页

作者： Jinlong wang Guoru Ding haichao wang College of Communications Engineering Army Engineering University of PLA National Mobile Communications Research Laboratory Southeast University

High frequency(HF) communication, commonly covering frequency range between 3 and 30 MHz, is an important wireless communication paradigm to offer over-thehorizon or even global communications with ranges up to thousands of kilometers via skywave propagation with ionospheric refraction. It has widespread applications in fields such as emergency communications in disaster areas, remote communications with aircrafts or ships and non-light-of-the-sight military operations. This tutorial article overviews the history of HF communication, demystifies the recent advances, and provides a preview of the next few years, which the authors believe will see fruitful outputs towards wideband, intelligent and integrated HF communications. Specifically, we first present brief preliminaries on the unique features of HF communications to facilitate general readers in the communication community. Then, we provide a historical review to show the technical evolution on the three generations of HF communication systems. Further, we highlight the key challenges and research directions. We hope that this article will stimulate more interests in addressing the technical challenges on the research and development of future HF radio communication systems.

关键词： HF communications skywave propagation ionospheric refraction cognitive radio artificial intelligence

Betaine affects muscle lipid metabolism via regulating the fatty acid uptake and oxidation in finishing pig

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Journal of Animal Science and Biotechnology 2018年第1期9卷 187-195页

作者： Sisi Li haichao wang Xinxia wang Yizhen wang Jie Feng Key Laboratory of Animal Nutrition & Feed Zhejiang Province College of Animal Science Zhejiang University

Background： Betaine affects fat metabolism in animals, but the specific mechanism is still not clear. The purpose of this study was to investigate possible mechanisms of betaine in altering lipid metabolism in muscle tissue in finishing ***： A total of 120 crossbred gilts（Landrace × Yorkshire × Duroc） with an average initial body weight of 70.1 kg were randomly allotted to three dietary treatments. The treatments included a corn–soybean meal basal diet supplemented with 0, 1250 or 2500 mg/kg betaine. The feeding experiment lasted 42 ***： Betaine addition to the diet significantly increased the concentration of free fatty acids（FFA） in muscle（P 〈 0.05）. Furthermore, the levels of serum cholesterol and high-density lipoprotein cholesterol were decreased（P 〈 0.05） and total cholesterol content was increased in muscle（P 〈 0.05） of betaine fed pigs. Experiments on genes involved in fatty acid transport showed that betaine increased expression of lipoprotein lipase（LPL）, fatty acid translocase/cluster of differentiation（FAT/CD36）, fatty acid binding protein（FABP3） and fatty acid transport protein（FATP1）（P 〈 0.05）. The abundance of fatty acid transport protein and fatty acid binding protein were also increased by betaine（P 〈 0.05）. As for the key factors involved in fatty acid oxidation, although betaine supplementation didn＇t affect the level of carnitine and malonyl-CoA, betaine increased mR NA and protein abundance of carnitine palmitransferase-1（CPT1）and phosphorylated-AMPK（P 〈 0.05）.Conclusions： The results suggested that betaine may promoted muscle fatty acid uptake via up-regulating the genes related to fatty acid transporter including FAT/CD36, FATP1 and FABP3. On the other hand, betaine activated AMPK and up-regulated genes related to fatty acid oxidation including PPARα and CPT1. The underlying mechanism regulating fatty acid metabolism in pigs supplemented with betaine is associated with the up-regulation of genes involved in fatty acid transport

关键词： Betaine Fatty acid intake Fatty acid oxidation Muscle Pig

Influence of C/Ti stoichiometry in TiC_x on the grain refinement efficiency of Al–Ti–C master alloy

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Journal of Materials Science & Technology 2017年第7期33卷 616-622页

作者： Huabing Yang Tong Gao haichao wang Jinfeng Nie Xiangfa Liu Nano Structural Materials Center School of Materials Science and Engineering Nanjing University of Science and Technology Nanjing 210094 China

TiC_x contained Al-Ti-C is a kind of grain refiner for Al alloys. In this work, the influence of C/Ti stoichiometry, i.e. the x value in TiC_x on grain refinement efficiency was investigated. TiC_x particles have been obtained in five Al-5Ti-m C（m = 0.1, 0.5, 0.8, 1, 1.25） master alloys and the x values were measured to be0.72, 0.75, 0.79, 0.81 and 0.8, respectively. It was found that the refinement performance of the master alloys had a close relationship with the x value of TiC_x . The Al-5Ti-m C alloy with lower-x TiC_x shows better refinement efficiency and anti-fading capability. It is supposed that TiC_x particles with lower x are more preferred to release Ti atoms during nucleating process and have a better Ti-absorbing *** contributes to the Ti-rich zone formation at TiC_x /melt interface, thus enhancing the refinement and anti-fading capability.

关键词： Al alloys Nucleation Grain refinement TiC_x

Network-Connected UAV Communications: Potentials and Challenges

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China Communications 2018年第12期15卷 111-121页

作者： haichao wang Jinlong wang Jin Chen Yuping Gong Guoru Ding College of Communications Engineering Army Engineering University National Mobile Communications Research Laboratory Southeast University

This article explores the use of network-connected unmanned aerial vehicle(UAV) communications as a compelling solution to achieve high-rate information transmission and support ultra-reliable UAV remote command and control. We first discuss the use cases of UAVs and the resulting communication requirements, accompanied with a flexible architecture for network-connected UAV communications. Then, the signal transmission and interference characteristics are theoretically analyzed, and subsequently we highlight the design and optimization considerations, including antenna design, nonorthogonal multiple access communications, as well as network selection and association optimization. Finally, case studies are provided to show the feasibility of network-connected UAV communications.

关键词： UAV communications signal transmission interference

Sustainability Evaluation of Modern Photovoltaic Agriculture Based on Interval Type-2 Fuzzy AHP-TOPSIS and Least Squares Support Vector Machine Optimized by Fireworks Algorithm

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Energy Engineering 2022年第1期119卷 163-188页

作者： Yi Liang haichao wang Wei-Chiang Hong School of Management Hebei GEO UniversityShijiazhuang050031China Strategy and Management Base of Mineral Resources in Hebei Province Hebei GEO UniversityShijiazhuang050031China Long Yuan(Beijing)Wind Power Engineering&Consulting Co. Ltd.Beijing100034China Department of Information Management Oriental Institute of TechnologyNew TaipeiTaiwanChina

Photovoltaics(PV)has been combined with many other industries,such as *** there are many problems for the sustainability of PV *** and accurate sustainability evaluation of modern photovoltaic agriculture is of great significance for accelerating the sustainable development of modern photovoltaic *** order to improve the timeliness and accuracy of evaluation,this paper proposes an evaluation model based on interval type-2 Fuzzy AHP-TOPSIS and least squares support vector machine optimized by fireworks ***,the criteria system of modern photovoltaic agriculture sustainability is constructed from three dimensions including technology sustainability,economic sustainability and social ***,analytic hierarchy process(AHP)and technique for order preference by similarity to an ideal solution(TOPSIS)methods are improved by using interval type-2 fuzzy theory,and the traditional evaluation model based on interval type-2 Fuzzy AHP-TOPSIS is obtained,and the improved model is used for comprehensive *** that,the optimal parameters of least squares support vector machine(LSSVM)model are obtained by Fireworks algorithm(FWA)training,and the intelligent evaluationmodel for the sustainability of modern photovoltaic agriculture is constructed to realize fast and intelligent ***,an empirical analysis is conducted to demonstrate the scientificity and accuracy of the proposed *** study is conducive to the comprehensive evaluation of the sustainability of modern photovoltaic agriculture,and can provide decision-making support for more reasonable development model in the future of modern photovoltaic agriculture.

关键词： Modern photovoltaic agriculture sustainability evaluation interval type-2 fuzzy numbers AHP TOPSIS FWA LSSVM

Navigation for UAV Pair-Supported Relaying in Unknown IoT Systems with Deep Reinforcement Learning

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Chinese Journal of Electronics 2022年第3期31卷 416-429页

作者： HUANG Fei LI Guangxia wang haichao TIAN Shiwei YANG Yang CHANG Jinghui The College of Communications Engineering Army Engineering University of PLA The National Innovation Institute of Defense Technology Chinese Academy of Military Sciences The Satellite Communication Center

Unmanned aerial vehicles(UAVs) have recently been regarded as a promising technology in Internet of things(IoT). UAVs functioned as intermediate relay nodes are capable of establishing uninterrupted and high-quality communication links between remotely deployed IoT devices and the destination. Multiple UAVs are required to be deployed due to their limited onboard energy. We study a UAV pair-supported relaying in unknown IoT systems, which consists of transmitter and receiver. Our goal is that transmitter gathers the data from each device then transfers the information to receiver,and receiver finally transmits the information to the destination, while meeting the constraint that the amount of information received from each device reaches a certain threshold. This is an optimization problem with highly coupled variables, such as trajectories of transmitter and receiver. On account of no prior knowledge of the environment, a dueling double deep Q network(dueling DDQN) algorithm is proposed to solve the *** it is in the phase of transmitter’s receiving information or the phase of transmitter’s forwarding information to receiver, the effectiveness and superiority of the proposed algorithm is demonstrated by extensive simulationsin in comparison to some base schemes under different scenarios.

关键词： deep reinforcement learning unmanned aerial vehicles deep learning (artificial intelligence) reinforcement learning transmitter UAV pair-supported relaying autonomous aerial vehicles high-quality communication links unknown IoT systems remotely deployed IoT devices aircraft navigation dueling DDQN algorithm Internet of Things intermediate relay nodes dueling double deep Q network algorithm

Formation mechanism and control strategy for particulate nitrate in China

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Journal of Environmental Sciences 2023年第1期123卷 476-486页

作者： haichao wang Keding Lu Zhaofeng Tan Xiaorui Chen Yuhan Liu Yuanhang Zhang School of Atmospheric Sciences Sun Yat-sen UniversityGuangzhou 510275China State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and EngineeringPeking UniversityBeijing 100871China Institute of Energy and Climate Research IEK-8:TroposphereForschungszentrum Jülich GmbHJülich 52428Germany Department of Civil and Environmental Engineering The Hong Kong Polytechnic UniversityHong Kong 999077China China Institute of Atomic Energy Beijing 100193China

Over the past decade,fine particulate matter(PM)pollution in China has been abated significantly,benefiting from strict emission control measures,but particulate nitrate continues to ***,we review the progress in particulate nitrate(p NO3-)pollution characterization,nitrate formation mechanisms,and the proposed control strategies in *** spatial and temporal distributions of p NO3-are *** current status of knowledge on the chemical mechanism is updated,and the significance of its formation pathways is assessed by various approaches such as field observation and modelling of nitrate production rate,as well as isotopic *** factors impacting p NO3-formation and the corresponding pollution regulation strategies are discussed,in which the importance of atmospheric oxidation capacity and ammonia are ***,the challenges and open questions in p NO3-pollution control in China are outlined.

关键词： Particulate nitrate Reactive nitrogen Particulate matter Formation mechanism Air pollution control

Fast spreading of surface ozone in both temporal and spatial scale in Pearl River Delta

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Journal of Environmental Sciences 2024年第3期137卷 540-552页

作者： Tianhui Cao haichao wang Lei Li Xiao Lu Yiming Liu Shaojia Fan School of Atmospheric Sciences Sun Yat-sen University and Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Zhuhai 519082China Guangdong Provincial Observation and Research Station for Climate Environment and Air Quality Change in the Pearl River Estuary Key Laboratory of Tropical Atmosphere-Ocean SystemMinistry of EducationZhuhai 519082China

Surface ozone(O_(3))is a major air pollutant and draw increasing attention in the Pearl River Delta(PRD),***,we characterize the spatial-temporal variability of ozone based on a dataset obtained from 57 national monitoring sites during *** results show that:(1)the seasonal difference of ozone distribution in the inland and coastal areas was significant,which was largely affected by the wind pattern reversals related to the East Asian monsoon,and local ozone production and destruction;(2)the daily maximum 8hr average(MDA8 O_(3))showed an overall upward trend by 1.11 ppbv/*** the trends in the nine cities varied differently by ranging from-0.12 to 2.51 ppbv/*** hot spots of ozone were spreading to southwestern areas from the central areas since *** ozone is becoming a year-round air pollution problem with the pollution season extending to winter and spring in PRD region.(3)at the central and southwestern PRD cities,the percentage of exceedance days from the continuous type(defined as≥3 days)was ***,the ozone concentration of continuous type was much higher than that of scattered exceedance type(<3 days).In addition,although the occurrence of continuous type starts to decline since2017,the total number of exceedance days during the continuous type is *** results indicate that it is more difficult to eliminate the continuous exceedance than the scatter pollution days and highlight the great challenge in mitigation of O_(3)pollution in these cities.

关键词： Surface ozone pollution Ozone trend Spatial and temporal variability Pearl River Delta Pollution mitigation

Sustainability Intelligent Evaluation of Regional Microgrid Interconnection System Based on Combination Entropy Weight Rank Order-TOPSIS and NILA-KELM

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Energy Engineering 2022年第3期119卷 1075-1101页

作者： haichao wang Yingying Fan Weigao Meng Qiaoran Yang Long Yuan(Beijing)Wind Power Engineering&Consulting Co. Ltd.Beijing100034China School of Art Hebei GEO UniversityShijiazhuang050031China Strategy and Management Base of Mineral Resources in Hebei Province Hebei GEO UniversityShijiazhuang050031China School of Urban Geology and Engineering Hebei GEO UniversityShijiazhuang050031China School of Management Hebei GEO UniversityShijiazhuang050031China

Sustainability evaluation of regional microgrid interconnection system is conducive to a profound and comprehensive understanding of the impact of interconnection system *** order to realize the comprehensive and scientific intelligent evaluation of the system,this paper proposes an evaluation model based on combination entropy weight rank order-technique for order preference by similarity to an ideal solution(TOPSIS)and Niche Immune Lion Algorithm-Extreme Learning Machine with Kernel(NILAKELM).Firstly,the sustainability evaluation indicator system of the regional microgrid interconnection system is constructed fromfour aspects of economic,environmental,social,and technical characteristics,and the evaluation indicators are ***,the classical evaluationmodel based on TOPSIS is constructed,and the entropy weight method and rank order method(RO)are coupled to obtain the indicator *** niche immune algorithm is used to improve the lion algorithm,and the improved lion algorithm is used to optimize the parameters of KELM,and the intelligent evaluation model based on NILA-KELM is obtained to realize fast real-time ***,the scientificity and accuracy of themodel proposed in this paper are *** model proposed in this paper has the lowest RMSE,MAE and RE values,indicating that its intelligent evaluation results are the most *** study is conducive to the horizontal comparison of the overall performance of regional microgrid interconnection system projects,helps investors to choose the most promising project scheme,and helps the government to find feasible project.

关键词： Regional microgrid interconnection system intelligent evaluation of sustainability combination entropy weight rank order TOPSIS NILA KELM