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| 1 | Towards 6G wireless communication networks:vision,enabling technologies,and new paradigm shifts显示文摘The fifth generation(5G)wireless communication networks are being deployed worldwide from 2020 and more capabilities are in the process of being standardized,such as mass connectivity,ultra-reliability,and guaranteed low latency.However,5G will not meet all requirements of the future in 2030 and beyond,and sixth generation(6G)wireless communication networks are expected to provide global coverage,enhanced spectral/energy/cost efficiency,better intelligence level and security,etc.To meet these requirements,6G networks will rely on new enabling technologies,i.e.,air interface and transmission technologies and novel network architecture,such as waveform design,multiple access,channel coding schemes,multi-antenna technologies,network slicing,cell-free architecture,and cloud/fog/edge computing.Our vision on 6G is that it will have four new paradigm shifts.First,to satisfy the requirement of global coverage,6G will not be limited to terrestrial communication networks,which will need to be complemented with non-terrestrial networks such as satellite and unmanned aerial vehicle(UAV)communication networks,thus achieving a space-airground-sea integrated communication network.Second,all spectra will be fully explored to further increase data rates and connection density,including the sub-6GHz,millimeter wave(mmWave),terahertz(THz),and optical frequency bands.Third,facing the big datasets generated by the use of extremely heterogeneous networks,diverse communication scenarios,large numbers of antennas,wide bandwidths,and new service requirements,6G networks will enable a new range of smart applications with the aid of artificial intelligence(AI)and big data technologies.Fourth,network security will have to be strengthened when developing 6G networks.This article provides a comprehensive survey of recent advances and future trends in these four aspects.Clearly,6G with additional technical requirements beyond those of 5G will enable faster and further communications to the extent that the boundary between physical and cyber worlds disappears. | Xiaohu YOU Cheng-Xiang WANG Jie HUANG Xiqi GAO Zaichen ZHANG Mao WANG Yongming HUANG Chuan ZHANG Yanxiang JIANG Jiaheng WANG Min ZHU Bin SHENG Dongming WANG Zhiwen PAN Pengcheng ZHU Yang YANG Zening LIU Ping ZHANG Xiaofeng TAO Shaoqian LI Zhi CHEN Xinying MA Chih-Lin I Shuangfeng HAN Ke LI Chengkang PAN Zhimin ZHENG Lajos HANZO Xuemin(Sherman)SHEN Yingjie Jay GUO Zhiguo DING Harald HAAS Wen TONG Peiying ZHU Ganghua YANG Jun WANG Erik GLARSSON Hien Quoc NGO Wei HONG Haiming WANG Debin HOU Jixin CHEN Zhe CHEN Zhangcheng HAO Geoffrey Ye LI Rahim TAFAZOLLI Yue GAO HVincent POOR Gerhard P.FETTWEIS Ying-Chang LIANG | 2021 | Science China(Information Sciences)2021，64，1： | 122 |
| 2 | Key techniques for 5G wireless communications:network architecture, physical layer,and MAC layer perspectives显示文摘The fourth generation(4G) mobile communication systems are offering service worldwide steadily.Although 4G systems could be loaded with much more services and data than previous systems, there is still a dramatic gap between the people's practical requirements and what can be offered by the 4G technologies.Consequently, the research and development for the fifth generation(5G) systems have already been started. This article presents an overview of potential network architecture and highlights several promising techniques which could be employed in the future 5G systems. These techniques include non-orthogonal multiple access(NOMA),massive multiple input and multiple output(MIMO), cooperative communications and network coding, full duplex(FD), device-to-device(D2D) communications, millimeter wave communications, automated network organization, cognitive radio(CR), and green communications. The state-of-art and implementation issue of these techniques are also addressed. | MA Zheng ZHANG ZhengQuan DING ZhiGuo FAN PingZhi LI HengChao | 2015 | Science China(Information Sciences)2015，58，4： | 49 |
| 3 | Nitrogen and phosphorus removal in pilot-scale anaerobic-anoxic oxidation ditch system显示文摘完成氮和磷移动的高效率并且调查同时的氮的硝化作用和脱氮磷移动( SNDPR )的规则, SNDPR 损坏和恢复的一堂整个功课在飞行员规模被学习,厌氧--缺氧的氧化阴沟( OD ),在此厌氧的地区的体积, OD 系统的缺氧的地区,和阴沟地区分别地是 7 , 21 ,和 280 L 。反应堆与 336 L/d 的流动率用市政的废水被喂。同时的氮的硝化作用和脱氮(SND ) 的概念率(rSND ) 被提出确定 SND。结果显示那:(1 ) 高氮和磷移动效率在稳定的 SND 阶段,总氮(TN ) 和磷酸盐(TP ) 移动评估的总数期间被完成分别地是 80% 和 85% ;(2 ) 当系统过分地被充气时, SND 的稳定性从 80% ~ 20% 或少些被损坏,并且 rSND 落下;(3 ) 到在自河的 NH4+ 的 NOx 的比率的自然对数有一道线性相关到氧化减小潜力(ORP ) ;(4 ) 什么时候 NO3?是不到 6 mg/L,高磷移动效率能被完成;(5 ) 从磷移动(DNPR ) 能发生在嫌气的,厌气的,厌氧的,缺氧缺氧的 OD 系统。主要革新是 SND 率被设计并且确定。 | PENG Yongzhen HOU Hongxun WANG Shuying CUI Youwei Zhiguo Yuan | 2008 | Journal of Environmental Sciences2008，20，4： | 35 |
| 4 | Glacial distribution and mass balance in the Yarlung Zangbo River and its influence on lakes显示文摘Glaciers in the Yarlung Zangbo River witness severe glacial retreat nowadays,which gives important influence on lake processes in the region.We have studied glacial distribution,glacial mass balance and found large deficit in glacial mass and its impact in the region.Our study also integrated the variation in glacial-fed lakes of the Nam Co and Ranwu Lake,and presented an initial assessment of the impact of glacial mass balance on lakes.The study has shown a significant contribution of glacial melting to recent lake expansion and lake level rising. | YAO TanDong LI ZhiGuo YANG Wei GUO XueJun ZHU LiPing KANG ShiChang WU YanHong YU WuSheng | 2010 | Chinese Science Bulletin2010，55，20： | 34 |
| 5 | Direct reprogramming of Sertoli cells into multipotent neural stem cells by defined factors显示文摘Multipotent 神经干细胞为房间治疗保持大诺言。到导致的 pluripotent 干细胞以及成熟神经原的成纤维细胞的 reprogramming 建议可能性没有首先建立 pluripotency,把一个严重地区分的体的房间变换成一个 multipotent 状态。这里,我们证明房间从中层导出的那 Sertoli 能直接被变换成拥有神经干细胞性质的一个 multipotent 状态。导致的神经干细胞(iNSCs ) 表示多重 NSC 特定的标记,展出类似于正常 NSC 的全球基因表示侧面,并且能够自强并且区分功能的神经原进神经胶质并且 electrophysiologically。为酷氨酸 hydroxylase (TH ) 积极的导出 iNSC 的神经原污点, γ -aminobutyric 酸,和胆碱 acetyltransferase。另外, iNSCs 能熬过并且产生跟随移植进有牙齿的回转的触处。iNSCs 的产生可以为疾病建模和再生药有重要含意。 | Chao Sheng Qinyuan Zheng Jianyu Wu Zhen Xu Libin Wang Wei Li Haijiang Zhang Xiao-Yang Zhao Lei Liu Ziwei Wang Changlong Guo Hua-Jun Wu Zhonghua Liu Liu Wang Shigang He Xiu-Jie Wang Zhiguo Chen Qi Zhou | 2012 | Cell Research2012，22，1： | 31 |
| 6 | Analysis of pesticide residues in commercially available chenpi using a modified QuEChERS method and GC-MS/MS determination显示文摘To ensure the safety of the commercially available chenpi,a convenient and fast analytical method was developed for the determination of 133 pesticide residues in chenpi using gas chromatography-tandem mass spectrometry(GC-MS/MS).In this study,different extraction solvents,redissolution solvents and adsorbents were tested according to the recovery and purification effect to obtain a modified QuEChERS method.The samples were extracted with acetonitrile.During the clean-up step,octadecyl-modified silica(C18)and graphitized carbon black(GCB)were selected,and aminopropyl(NH2)was used instead of primary secondary amine(PSA)because of its weaker ion exchange capacity which had little effect on the recovery of ditalimfos.Samples were quantified by matrix-matched calibration with internal standards.All pesticides showed good linearity in the respective range,both with values of r2>0.99.The average recoveries of the pesticides spiked samples ranged from 70.0% to 112.2% with the RSDs of 0.2%–14.4%.The modified QuEChERS method was validated and applied to twenty real samples.Five pesticides were found in eight batches,but no pesticide exceeded the maximum residue limits(MRL,MRL reference to European commission). | Shuang Li Peipei Yu Ceng Zhou Ling Tong Dongxiang Li Zhiguo Yu Yunli Zhao | 2020 | Journal of Pharmaceutical Analysis2020，10，1： | 34 |
| 7 | Recent advances in solid-state LED phosphors with thermally stable luminescence显示文摘Phosphor-converted white light-emitting diode(LED) lighting has gained tremendous achievements since the invention of the InGaN blue LED by Nakamura et al., who won the Nobel Physics Prize in 2014.By far, a significant challenge comes from the thermal quenching(TQ) behavior of the present LED phosphors during the high-power LED operation or the updated laser lighting. But systematic research or review on the luminescence quenching character and/or how to realize thermally stable luminescence are lacking. Since TQ is an inherent property of phosphors, it can be diminished by different approaches.This review proceeds from the mechanism of TQ, summarizes previous researches on improving the thermal stability of LED phosphors and also discusses future research opportunities in this field. The developments of the phosphors with properties of high luminance and thermal stability, as well as the improved strategies involved,will benefit the basic researches and applications in high power lighting or high-luminance laser lighting. | Jianwei Qiao Jing Zhao Quanlin Liu Zhiguo Xia | 2019 | Journal of Rare Earths2019，37，6： | 34 |
| 8 | Palaeogeothermal response and record of the effusing of Emeishan basalts in the Sichuan basin显示文摘Thermal history of the Sichuan basin is reconstructed based on vitrinite reflectance from boreholes in the basin using a paleo-heat flow method.The results show that the Sichuan basin experienced a relatively low heat flow period in the Early Paleozoic,and an elevated paleo-heat flow,ranging 60-80 mW/m2 with a maximum as high as 100 mW/m2 around 259 Ma,from the beginning of the Late Paleozoic to the end of the early Permian,and a decreased paleo-heat flow from the late Permian to the late Triassic,and then maintained nearly stable to the present.The Late Paleozoic paleo-heat flow was quite high where there were extensive Emeishan flood basalts or concealed basalts which erupted between the early and the late Permian,such as the southwestern and northeastern areas of the Sichuan basin.According to the distribution of paleo-heat flow,it can be inferred that,the northeastern Sichuan basin was also influenced by the Emeishan magmatic activity during the Dongwu movement though there was lack of Emeishan flood basalts.In addition,the results of thermal history reconstruction of the Sichuan basin provide paleogeothermal evidence for the existence and onset of the Emaishan mantle plume. | ZHU ChuanQing XU Ming YUAN YuSon ZHAO YongQing SHAN JingNan HE ZhiGuo TIAN YunTao HU ShengBiao | 2010 | Chinese Science Bulletin2010，55，10： | 30 |
| 9 | Variations of organic carbon isotopic composition and its environmental significance during the last glacial on western Chinese Loess Plateau显示文摘A high-resolution loess section in the western Chinese Loess Plateau, Yuanbao Section, was sampled for organic carbon isotopic analyses. The soil organic carbon isotope (δ13Corg) varied be- tween ?22.6‰ and ?27.5‰ during the last glacial at the section. During the last interstadial, the δ 13Corg values were more negative than those in both early and late periods of the last glacial by 4‰. The iso- topic composition indicates a coupled response of the pure C3 plants to the temperature, precipitation and the concentration of atmospheric CO2. Decrease in temperature and the atmospheric CO2 concentration from the last interstadial to Last Glaicial Maximum (LGM) caused the organic carbon isotopes to be- come positive by 1.5‰―2.0‰. The amplitude of 4‰ in the δ 13Corg variation during the last glacial should be mainly caused by the precipitation change. Therefore, the δ 13Corg variations of the Yuanbao Section during the last glacial period documented the large-amplitude fluctuation of the monsoon precipita- tion, which is estimated to be 250―310 mm more during the last interstadial than that in the LGM, and 100 mm more than that during early last glacial. The rapid changes of the monsoon precipitation on mil-lennial scale during the last glacial have also been recorded in the isotopic variations in Yuanbao loess section. As the isotopic composition varies compli- catedly as shown in the loess-paleosol sequence, it cannot be simply attributed to the abundances of C3 and C4 plants or be used as an indicator of the summer monsoon variations. | CHEN Fahu RAO Zhiguo ZHANG Jiawu JIN Ming MA Jianying | 2006 | Chinese Science Bulletin2006，51，13： | 25 |
| 10 | Emerging ultra-narrow-band cyan-emitting phosphor for white LEDs with enhanced color rendition显示文摘Phosphor-converted white LEDs rely on combining a blue-emitting InGaN chip with yellow and red-emitting luminescent materials.The discovery of cyan-emitting(470-500 nm)phosphors is a challenge to compensate for the spectral gap and produce full-spectrum white light.Na_(0.5)K_(0.5)Li_(3)SiO_(4):Eu^(2+)(NKLSO:Eu^(2+))phosphor was developed with impressive properties,providing cyan emission at 486 nm with a narrow full width at half maximum(FWHM)of only 20.7 nm,and good thermal stability with an integrated emission loss of only 7% at 150℃.The ultra-narrow-band cyan emission results from the high-symmetry cation sites,leading to almost ideal cubic coordination for UCr_(4)C_(4)-type compounds.NKLSO:Eu^(2+) phosphor allows the valley between the blue and yellow emission peaks in the white LED device to be filled,and the color-rendering index can be enhanced from 86 to 95.2,suggesting great applications in full-spectrum white LEDs. | Ming Zhao Hongxu Liao Maxim S.Molokeev Yayun Zhou Qinyuan Zhang Quanlin Liu Zhiguo Xia | 2019 | Light(Science & Applications)2019，8，1： | 21 |
| 11 | Geochronological evidence for existence of South Mongolian microcontinent——A zircon U-Pb age of grantoid gneisses from the Yagan-Onch Hayr-han metamorphic core complex显示文摘A zircon U-Pb age of (916±16) Ma is measured for grantoid gneisses from the Yagan-Onch Hayrhan metamorphic core complex and represents the crystallization age of the grantoid magma. This age provides evidence for the existence of the South Mongolian microcontinent, which is consistent with the analysis of the regional geology. | WANG Tao ZHENG Yadong G.E.Gehrels MU Zhiguo | 2001 | Chinese Science Bulletin2001，46，23： | 20 |
| 12 | Formation mechanisms of megadunes and lakes in the Badain Jaran Desert,Inner Mongolia显示文摘Field observations demonstrate that calc-sinters occurred in the lakes of Badain Jaran Desert. 87Sr/86Sr ratios,14C,δ 13C and mineral com-positions of calc-sinters,and 3He/4He,4He/20Ne,δ 18O,δ D,pH and TDS of water from springs and lakes are analyzed in detail. The results indicate that the lake water is supplied through deep fault zone. The “ker-nel” of stabilized dunes in the Badain Jaran Desert perhaps consists of calc-sinters and calcareous ce-mentation layers. Deep-seated groundwater effuses from this “kernel” and recharges to lakes in desert. Precipitation and snowmelt water from the Qing-hai-Tibet Plateau is fed into the Badain Jaran Desert,Gurinai,Wentougaole and Ejinqi areas through the Xigaze-Langshan Fault zone. The isotopic composi-tions of groundwater in the Alax Plateau are abnor-mal due to the strong evaporation of the Gyaring and Ngoring lake water in the headstream of the Yellow River. Groundwater dissolves dissoluble fractions of rocks during its transportation through the fault zone and flows out of the mouth of spring in the Badan Jaran Desert. The dissoluble fractions are finally de-veloped into calc-sinters and calcareous cementation layers around the spring. Calci-sinters are gradually largened and eventually emerge on the surface of lake water. Eolian sands accumulate on the surfaces of calc-sinters and calcareous cementation layers,and eventually develop into dunes. Invasion of magma causes an increase in the temperature of groundwater within the faults. Groundwater evapora-tion provides water vapor for the formation of humid stabilized dunes during its upwelling. Rhizoconcre-tions found in Yihejigede indicate that the dune was formed and remained immovable 4700 years ago. The height of the megadunes is proportional to thermal quantity carried by the groundwater. | CHEN Jiansheng ZHAO Xia SHENG Xuefen DONG Haizhou RAO Wenbo SU Zhiguo | 2006 | Chinese Science Bulletin2006，51，24： | 19 |
| 13 | On the timing of the East Asian summer monsoon maximum during the Holocene Does the speleothem oxygen isotope record reflect monsoon rainfall variability?显示文摘The evolution of the East Asian summer monsoon(EASM) during the Holocene has long been of significant interest.Knowledge of past EASM variability not only increases our understanding of monsoon dynamics on a long timescale,but it also provides an environmental and climatic background for research into Chinese cultural development.However,the timing of the EASM maximum remains controversial.The popular concept of an 'early Holocene maximum' is mainly based on speleothemδ^(18)O(δ^(18)O_c) records from caves in southern China;however,the interpretation of δ^(18)O_C as a reliable proxy for EASM intensity is being increasingly challenged.The present paper is a critical review of the climatic significance of the δ^(18)O_C record from China.Firstly,we suggest that precipitation in northern China is an appropriate index of EASM intensity,the variation of which clearly indicates a mid-Holocene monsoon maximum.Secondly,an interregional comparison demonstrates that the precipitation record in northern China is quite different from that in southern China on a range of timescales,and is inconsistent with the spatial similarity exhibited by speleothem oxygen isotope records.Furthermore,both modeling and observational data show that the δ^(18)O_C records from southern China indeed reflect changes in precipitation δ^(18)O(δ^(18)O_P) rather than precipitation amount,and therefore that their use as an EASM proxy is inappropriate.Finally,we address several significant monsoon-related issues-including the driving mechanism of the EASM on an orbital timescale,the climatic significance of speleothem oxygen isotopes,and the relationship between atmospheric circulation and precipitation in monsoonal regions. | CHEN JianHui RAO ZhiGuo LIU JianBao HUANG Wei FENG Song DONG GuangHui HU Yu XU QingHai CHEN FaHu | 2016 | Science China(Information Sciences)2016，59，12： | 18 |
| 14 | Measuring reliability under epistemic uncertainty:Review on non-probabilistic reliability metrics显示文摘In this paper,a systematic review of non-probabilistic reliability metrics is conducted to assist the selection of appropriate reliability metrics to model the influence of epistemic uncertainty.Five frequently used non-probabilistic reliability metrics are critically reviewed,i.e.,evidencetheory-based reliability metrics,interval-analysis-based reliability metrics,fuzzy-interval-analysisbased reliability metrics,possibility-theory-based reliability metrics(posbist reliability) and uncertainty-theory-based reliability metrics(belief reliability).It is pointed out that a qualified reliability metric that is able to consider the effect of epistemic uncertainty needs to(1) compensate the conservatism in the estimations of the component-level reliability metrics caused by epistemic uncertainty,and(2) satisfy the duality axiom,otherwise it might lead to paradoxical and confusing results in engineering applications.The five commonly used non-probabilistic reliability metrics are compared in terms of these two properties,and the comparison can serve as a basis for the selection of the appropriate reliability metrics. | Kang Rui ZhangQingyuan Zeng Zhiguo Enrico Zio Li Xiaoyang | 2016 | Chinese Journal of Aeronautics2016，29，3： | 18 |
| 15 | A new criterion of coal burst proneness based on the residual elastic energy index显示文摘To evaluate the coal burst proneness more precisely,a new energy criterion namely the residual elastic energy index was proposed.This study begins by performing the single-cyclic loading-unloading uniaxial compression tests with five pre-peak unloading stress levels to explore the energy storage characteristics of coal.Five types of coals from different mines were tested,and the instantaneous destruction process of the coal specimens under compression loading was recorded using a high speed camera.The results showed a linear relationship between the elastic strain energy density and input energy density,which confirms the linear energy storage law of coal.Based on this linear energy storage law,the peak elastic strain energy density of each coal specimen was obtained precisely.Subsequently,a new energy criterion of coal burst proneness was established,which was called the residual elastic energy index(defined as the difference between the peak elastic strain energy density and post peak failure energy density).Considering the destruction process and actual failure characteristics of coal specimens,the accuracy of evaluating coal burst proneness based on the residual elastic energy index was examined.The results indicated that the residual elastic energy index enables reliable and precise evaluations of the coal burst proneness. | Fengqiang Gong Yunliang Wang Zhiguo Wang Junfeng Pan Song Luo | 2021 | International Journal of Mining Science and Technology2021，31，4： | 16 |
| 16 | The RNA Editing Factor WSP1 Is Essentia for Chloroplast Development in Rice显示文摘尽管在 Arabidopsis thaliana 的质体编辑因素(MORF ) 的多重 organellar RNA 是位于下面 MORF 怎么在另外的种类影响植物开发的广泛地学习的、分子的细节,特别地在米饭,仍然保持大部分未知。这里,我们描述 wsp1 的描述,有白条纹的叶子和圆锥花序的米饭异种。尤其是, wsp1 在出发舞台展出了将近白的不成熟的圆锥花序。传播电子显微镜学分析和叶绿素内容测量揭示了叶绿体在 wsp1 的发展缺点和减少的叶绿素累积。在 Os04g51280 发现一个点变化的 WSP1 的位置的克隆,份额其通常认为的产品高与 MORF 蛋白质定序类似。互补实验证明 WSP1 为 wsp1 的使成杂色的显型负责。WSP1 对叶绿体局部性,在 wsp1 的点变化影响编辑多重 organellar RNA 地点。由于在编辑的质体 RNA 的缺点,叶绿体核糖体生物的续生说并且 ndhA 拼接也在 wsp1 被损害,它可以在出发阶段在叶子和圆锥花序影响正常叶绿体开发。一起,我们的结果在叶绿体开发表明米饭 WSP1 蛋白质的重要性并且在米饭关于 MORF 家庭成员拓宽我们的知识。 | Zhiguo Zhang Xuean Cui Yanwei Wang JinxiaWu Xiaofeng Gu Tiegang Lu | 2017 | Molecular Plant2017，10，1： | 15 |
| 17 | Xuebijing injection alleviates liver injury by inhibiting secretory function of Kupffer cells in heat stroke rats显示文摘OBJECTIVE:To evaluate the effects of Xuebijing(XBJ) injection in heat stroke(HS) rats and to investigate the mechanisms underlying these effects.METHODS:Sixty anesthetized rats were randomized into three groups and intravenously injected twice daily for 3 days with 4 mL XBJ(XBJ group) or phosphate buffered saline(HS and Sham groups) per kg body weight.HS was initiated in the HS and XBJ groups by placing rats in a simulated climate chamber(ambient temperature 40 ℃,humidity 60%).Rectal temperature,aterial pressure,and heart rate were monitored and recorded.Time to HS onset and survival were determined,and serum concentrations of tumor necrosis factor(TNF)-α,inRESULTS:Time to HS onset and survival were significantly longer in the XBJ than in the HS group.Moreover,the concentrations of TNF-α,IL-1β,IL-6,ALT and AST were lower and liver injury was milder in the XBJ than in the HS group.Heat-stress induced structural changes in KCs and hepatic cells were more severe in the HS than in the XBJ group and the concentrations of TNF-α,IL-β and IL-6 secreted by KCs were lower in the XBJ than in the HS group.CONCLUSION:XBJ can alleviate HS-induced systemic inflammatory response syndrome and liver injury in rats,and improve outcomes.These protective effects may be due to the ability of XBJ to inhibit cytokine secretion by KCs. | Yi Chen Huasheng Tong Xingqin Zhang Liqun Tang Zhiguo Pan Zhifeng Liu Pengkai Duan Lei Su | 2013 | Journal of Traditional Chinese Medicine2013，33，2： | 14 |
| 18 | Testing method and distribution characteristics of spatial pesticide spraying deposition quality balance for unmanned aerial vehicle显示文摘In order to explore the spatial pesticide spraying deposition distribution,the downwash flow field characteristics for unmanned aerial vehicle(UAV)pesticide application with accurate flight height and velocity and the relationship of these two aspects,a novel measurement method was proposed in this paper.A model‘3WQF80-10’single-rotor diesel UAV was tested using this method in wheat field and the effects of flight direction,flight parameters and crosswind on the distribution of spatial spraying deposition quality balance(SSDQB)and the downwash flow field distribution were researched.A cuboid aluminum sampling frame of spatial spraying deposition quality balance(SFSSDQB)with monofilament wires was made for collecting the droplets in four directions,and a set of multi-channel micro-meteorology measurement system(MMMS)was applied for measuring the downwash wind speed in three directions.Besides,BeiDou Navigation Satellite System(BNSS)was used for controlling and recording the working height,velocity and track of this model of single-rotor UAV.The results showed the distribution of the spatial spray deposition and the downwash flow field of UAV could be measured effectively at exact flight height and velocity via this method.When the average wind speed was 0.9 m/s,the average temperature was 31.5℃ and the average relative humidity was 34.1%,and the average distribution ratios of spraying deposition for model‘3WQF80-10’UAV on the upwind part,the top part,the downwind part and the bottom part were 4.4%,2.3%,50.4%and 43.7%,respectively.The flight directions of forward and backward had an impact on droplet deposition distribution and the working effect of flying backwards,with 60%of deposition ratio of the bottom part of the SFSSDQB,was better than flying forward.There was a linear negative correlation between the coefficient of variation(CV)of the bottom part and the flight height and the coefficient of determination was 0.9178,which means that the deposition distribution becomes more uniform with the increase of height.Additionally,there was a linear positive correlation between weighted mean deposition rate and crosswind speed and the coefficient of determination was 0.9684,which shows the deposition distribution gets more concentrated towards the downwind part with the rise of crosswind speed.Therefore,according to the results of tests of downwash airflow speed,it is shown that regardless of the flight direction and height and the crosswind,all these factors influence the droplet deposition distribution via weakening the intensity of the downwash airflow field in the direction perpendicular to the ground.The results can provide valuable information for the research of UAV pesticide application techniques and the establishment of the standard of spraying deposition and drift tests of UAV in crop field. | Changling Wang Xiongkui He Xiaonan Wang Zhichong Wang Shilin Wang Longlong Li Jane Bonds Andreas Herbst Zhiguo Wang | 2018 | International Journal of Agricultural and Biological Engineering2018，11，2： | 14 |
| 19 | Effects of vegetation on flow conveyance and sediment transport capacity显示文摘In-stream and riparian vegetation may significantly affect flow and sediment transport in vegetated channels. A hydraulic model has been developed in this paper to compute the flow discharge in channels with rigid and flexible vegetation under emergent and submerged conditions. An empirical formula has also been presented to determine the bed-load discharge in vegetated channels. The model has been tested against experimental and field data available in the literature. The computed flow discharge and bed-load transport rate agree well with the measured data. | Weiming WU Zhiguo HE | 2009 | International Journal of Sediment Research2009，24，3： | 13 |
| 20 | High speed robust image registration and localization using optimized algorithm and its performances evaluation显示文摘Local invariant algorithm applied in downward-looking image registration,usually computes the camera's pose relative to visual landmarks.Generally,there are three requirements in the process of image registration when using these approaches.First,the algorithm is apt to be influenced by illumination.Second,algorithm should have less computational complexity.Third,the depth information of images needs to be estimated without other sensors.This paper investigates a famous local invariant feature named speeded up robust feature(SURF),and proposes a highspeed and robust image registration and localization algorithm based on it.With supports from feature tracking and pose estimation methods,the proposed algorithm can compute camera poses under different conditions of scale,viewpoint and rotation so as to precisely localize object's position.At last,the study makes registration experiment by scale invariant feature transform(SIFT),SURF and the proposed algorithm,and designs a method to evaluate their performances.Furthermore,this study makes object retrieval test on remote sensing video.For there is big deformation on remote sensing frames,the registration algorithm absorbs the Kanade-Lucas-Tomasi(KLT) 3-D coplanar calibration feature tracker methods,which can localize interesting targets precisely and efficiently.The experimental results prove that the proposed method has a higher localization speed and lower localization error rate than traditional visual simultaneous localization and mapping(vSLAM) in a period of time. | Meng An Zhiguo Jiang Danpei Zhao | 2010 | Journal of Systems Engineering and Electronics2010，21，3： | 13 |
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