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| 1 | An area-based position and attitude estimation for unmanned aerial vehicle navigation显示文摘The paper aims to challenge non-GPS navigation problems by using visual sensors and geo-referenced images. An area-based method is proposed to estimate full navigation parameters(FNPs), including attitude, altitude and horizontal position, for unmanned aerial vehicle(UAV) navigation. Our method is composed of three main modules: geometric transfer function, local normalized sobel energy image(LNSEI) based objective function and simplex-simulated annealing(SSA) based optimization algorithm. The adoption of relatively rich scene information and LNSEI, makes it possible to yield a solution robustly even in the presence of very noisy cases, such as multi-modal and/or multi-temporal images that differ in the type of visual sensor, season, illumination, weather, and so on, and also to handle the sparsely textured regions where features are barely detected or matched. Simulation experiments using many synthetic images clearly support noise resistance and estimation accuracy, and experimental results using 2367 real images show the maximum estimation error of 5.16(meter) for horizontal position, 9.72(meter) for altitude and 0.82(degree) for attitude. | LIU XiaoChun WANG Hou FU Dan YU QiFeng GUO PengYu LEI ZhiHui SHANG Yang | 2015 | Science China(Technological Sciences)2015，58，5： | 7 |
| 2 | Characteristics of reactivity and structures of palm kernel shell (PKS) biochar during CO_2/H_2O mixture gasification显示文摘Palm kernel shell(PKS)biochars with different levels of carbon conversion were initially prepared using a tube furnace,after which the reactivity of each sample was assessed with a thermogravimetric analyzer under a CO_2 atmosphere.The pore structure and carbon ordering of each biochar also examined,employing a surface area analyzer and a Raman spectroscopy.Thermogravimetric results showed that the gasification index R_sof the PKS biochar decreased from 0.0305 min^(-1) at carbon conversion(x)=20% to 0.0278 min^(-1)at x=40%.The expansion of micropores was the dominant process during the pore structure evolution,ad mesopores with sizes ranging from 6 to 20,48 to 50 nm were primarily generated during gasification under a CO_2/H_2O mixture.The proportion of amorphous carbon in the PKS biochar decreased significantly as x increased,suggesting that the proportion of ordered carbon was increased during the CO_2/H_2O mixed gasification.A significantly reduced total reaction time was observed when employing a CO_2/intermittent H_2O process along with an 83.46% reduction in the steam feed,compared with the amount required using a CO_2/H_2O atmosphere. | Guozhang Chang Ximin Yan Pengyu Qi Mei An Xiude Hu Qingjie Guo | 2018 | Chinese Journal of Chemical Engineering2018，26，10： | 3 |
| 3 | Enlightenments of “White Space” in Traditional Chinese Painting on Landscape Architecture Design显示文摘By analyzing different expressions of 'white space' in classical and modern Chinese gardens, the authors proposed that 'white space' theory has infiltrated in graphic and spatial designs and has been widely applied in spatial layouts of gardens. On the basis of elaborating conceptual origin, characteristics and its connotations in the creation of artistic ambience, 'white space' was believed valuable and enlightening for the artistic creation of modern landscape architecture. | LI Pengyu GUO Yifan LI Yi ZHU Qi | 2013 | Journal of Landscape Research2013，5，Z1： | 2 |
| 4 | Orbital rendezvous performance comparison of differential geometric and ZEM/ZEV feedback guidance algorithms显示文摘In this paper,the performance of two distinct classes of feedback guidance algorithms is evaluated for a spacecraft rendezvous problem utilizing a continuous low-thrust propulsion system.They are the DG(Differential Geometric)and ZEM/ZEV(Zero-Effort-Miss/Zero-Effort-Velocity)feedback guidance algorithms.Even though these two guidance algorithms do not attempt to minimize the onboard fuel consumption orΔV directly,theΔV requirement is used as a measure of their orbital rendezvous performance for various initial conditions and a wide range of the rendezvous time(within less than one orbital period of the target vehicle).For the DG guidance,the effects of its guidance parameter and terminal time on the closed-loop performance are evaluated by numerical simulations.For the ZEM/ZEV guidance,its nearfuel-optimality is further demonstrated for a rapid,short-range orbital rendezvous,in comparison with the corresponding open-loop optimal solutions.Furthermore,the poorΔV performance of the ZEM/ZEV guidance for a slow,long-range orbital rendezvous is remedied by simply adding an initial drift phase.The ZEM/ZEV feedback guidance algorithm and its appropriate variants are then shown to be a simple practical solution to a non-impulsive rendezvous problem,in comparison with the DG guidance as well as the open-loop optimal guidance. | Pengyu Wang Yanning Guo Bong Wie | 2019 | Astrodynamics2019，3，1： | 2 |
| 5 | Near-infrared quantum cutting in Ho 3+ , Yb 3+ -codoped BaGdF 5 nanoparticles via first-and second-order energy transfers显示文摘 | Linna Guo Yuhua Wang Jia Zhang Yanzhao Wang Pengyu Dong | 2012 | Nanoscale Research Letters2012，，1： | 1 |
| 6 | Optimal terminal-time determination for the ZEM/ZEV feedback guidance law with generalized performance index显示文摘This paper investigates a problem of determining the optimal terminal-time or time-to-go of the ZEM/ZEV(Zero-E ort-Miss/Zero-E ort-Velocity)feedback guidance law for a variety of orbital intercept or rendezvous maneuvers.A generalized ZEM/ZEV guidance problem,whose objective is to minimize a combination of the control energy and terminal time,is examined.Algebraic equations whose solution provides the optimal terminal-time of the orbital intercept/rendezvous problems are derived based on the optimal control theory.The e ectiveness of the proposed approach is demonstrated for various orbital maneuver problems. | Jaemyung Ahn Pengyu Wang Yanning Guo Bong Wie | 2019 | Astrodynamics2019，3，2： | 1 |
| 7 | Airborne Vision-Based Navigation Method for UAV Accuracy Landing Using Infrared Lamps显示文摘 | Yang Gui Pengyu Guo Hongliang Zhang Zhihui Lei Xiang Zhou Jing Du Qifeng Yu | 2013 | Journal of Intelligent & Robotic Systems2013，，2： | 1 |
| 8 | Chemically bonded multi-nanolayer inorganic aerogel with a record-low thermal conductivity in a vacuum显示文摘Inorganic aerogels have exhibited many superior characteristics with extensive applications,but are still plagued by a nearly century-old tradeoff between their mechanical and thermal properties.When reducing thermal conductivity by ultralow density,inorganic aerogels generally suffer from large fragility due to their brittle nature or weak joint crosslinking,while enhancing the mechanical robustness by material design and structural engineering,they easily sacrifice thermal insulation and stability.Here,we report a chemically bonded multi-nanolayer design and synthesis of a graphene/amorphous boron nitride aerogel to address this typical tradeoff to further enhance mechanical and thermal properties.Attributed to the chemically bonded interface and coupled toughening effect,our aerogels display a low density of 0.8 mg cm-3 with ultrahigh flexibility(elastic compressive strain up to 99%and bending strain up to 90%),and exceptional thermostability(strength degradation<3%after sharp thermal shocks),as well as the lowest thermal conductivities in a vacuum(only 1.57 mW m-1 K-1 at room temperature and 10.39 mW m-1 K-1 at500℃)among solid materials to date.This unique combination of mechanical and thermal properties offers an attractive material system for thermal superinsulation at extreme conditions. | Hongxuan Yu Menglin Li Yuanpeng Deng Shubin Fu Jingran Guo Han Zhao Jianing Zhang Shixuan Dang Pengyu Zhang Jian Zhou Dizhou Liu Duola Wang Chuanwei Zhang Menglong Hao Xiang Xu | 2023 | National Science Review2023，10，10： | 0 |
| 9 | Carbonaceous ceramic nanofibrous aerogels for high-temperature thermal superinsulation显示文摘Ultralight ceramic aerogels are attractive thermal superinsulating materials,but display a formidable tradeoff between low and high temperature thermal conductivity(κ)due to their low-density features.Embedding carbon species as infrared opacifier in ultralight ceramic aerogels can substantially reduce the thermal radiation heat transfer without compromising the ultralow solid conduction.However,the oxidation resistance of embedded carbon species still remains inadequate to prevent thermal etching at high temperatures.Herein,we report a carbonaceous design and synthesis of ceramic nanofibrous aerogels with amorphous carbon embedded in the yttrium-stabilized zircon nanofibers to achieve a high-temperature thermal superinsulating performance with robust thermomechanical stability.The aerogels display one of the lowestκof 95 mW·m^(−1)·K^(-1)at 1,000℃in air among ultralight material family,as well as robust mechanical flexibility with up to 95%compressive strain,30%non-linear fracture strain,and 99%bending strain,and high thermal stability with ultralow strength degradation less than 1%after sharp thermal shocks(240℃·s^(-1))and working temperature up to 1,200℃.The combined high-temperature thermal superinsulating and thermomechanical properties offer an attractive material system for robust thermal insulation under extreme conditions. | Shubin Fu Dizhou Liu Yuanpeng Deng Jingran Guo Han Zhao Jian Zhou Pengyu Zhang Hongxuan Yu Shixuan Dang Jianing Zhang Hui Li Xiang Xu | 2023 | Nano Research2023，16，4： | 0 |
| 10 | Stress sensitivity of carbonate gas reservoirs and its microscopic mechanism显示文摘In order to evaluate the stress sensitivity of carbonate reservoirs,a series of rock stress sensitivity tests were carried out under in-situ formation temperature and stress condition.Based on the calibration of capillary pressure curve,the variable fractal dimension was introduced to establish the conversion formula between relaxation time and pore size.By using the nuclear magnetic resonance(NMR)method,the pore volume loss caused by stress sensitivity within different scales of pore throat was quantitatively analyzed,and the microscopic mechanism of stress sensitivity of carbonate gas reservoirs was clarified.The results show that fractures can significantly affect the stress sensitivity of carbonate reservoirs.With the increase of initial permeability,the stress sensitivity coefficient decreases and then increases for porous reservoirs,but increases monotonously for fractured-porous reservoirs.The pore volume loss caused by stress sensitivity mainly occurs for mesopores(0.02–0.50μm),contributing more than 50%of the total volume loss.Single high-angle fracture contributes 9.6%of the stress sensitivity and 15.7%of the irreversible damage.The microscopic mechanism of the stress sensitivity of carbonate gas reservoirs can be concluded as fracture closure,elastic contraction of pores and plastic deformation of rock skeleton. | CHENG Youyou GUO Chunqiu CHEN Pengyu SHI Haidong TAN Chengqian CHENG Muwei XING Yuzhong LUO Xiang | 2023 | Petroleum Exploration and Development2023，50，1： | 0 |
| 11 | Simultaneously realizing good volumetric entropy change and mechanical strength of La_(0.8)Ce_(0.2)Fe_(11.51)Mn_(0.19)Si_(1.3)H_(y) plates显示文摘It is hard to get a high-strength La(Fe,Si)_(13)-based hydrides owing to the brittle feature of hydrides.In this work,we fabricated the La_(0.8)Ce_(0.2)Fe_(11.51)Mn_(0.19)Si_(1.3)plates through hot pressing at 1323 K for various time.Subsequently,the saturated hydrogenization is achieved at 593 K in H_2 atmosphere of 0.13 MPa for 210 min.The microstructure and magnetocaloric properties were investigated by an X-ray diffractometer,a scanning electron microscope and the Versa-Lab.Under magnetic fields of 0-2 T,the maximal volumetric entropy change is 91.4 mJ/(cm^(3)·K)at 297 K for the hydride plates.The hydride plate simultaneously has excellent mechanical properties with the maximum bending strength of 213 MPa,which suggest that the hot pressing followed by hydrogenation could be an effective route of fabricating La(Fe,Si)_(13)-based hydrides for the potential application in the magnetic refrigerator. | Juan Cheng Caiyin You Bo Li Yaru Guo Zhaojie Li Lei Gao Pengyu Wang | 2023 | Journal of Rare Earths2023，41，10： | 0 |
| 12 | Human intrusion detection for high-speed railway perimeter under all-weather condition显示文摘Purpose – The paper aims to solve the problem of personnel intrusion identification within the limits of highspeed railways. It adopts the fusion method of millimeter wave radar and camera to improve the accuracy ofobject recognition in dark and harsh weather conditions.Design/methodology/approach – This paper adopts the fusion strategy of radar and camera linkage toachieve focus amplification of long-distance targets and solves the problem of low illumination by laser lightfilling of the focus point. In order to improve the recognition effect, this paper adopts the YOLOv8 algorithm formulti-scale target recognition. In addition, for the image distortion caused by bad weather, this paper proposesa linkage and tracking fusion strategy to output the correct alarm results.Findings – Simulated intrusion tests show that the proposed method can effectively detect human intrusionwithin 0–200 m during the day and night in sunny weather and can achieve more than 80% recognitionaccuracy for extreme severe weather conditions.Originality/value – (1) The authors propose a personnel intrusion monitoring scheme based on the fusion ofmillimeter wave radar and camera, achieving all-weather intrusion monitoring;(2) The authors propose a newmulti-level fusion algorithm based on linkage and tracking to achieve intrusion target monitoring underadverse weather conditions;(3) The authors have conducted a large number of innovative simulationexperiments to verify the effectiveness of the method proposed in this article. | Pengyue Guo Tianyun Shi Zhen Ma Jing Wang | 2024 | Railway Sciences2024，3，1： | 0 |
| 13 | No evidence of superconductivity in a compressed sample prepared from lutetium foil and H_(2)/N_(2) gas mixture显示文摘A material described as lutetium–hydrogen–nitrogen(Lu-H-N in short)was recently claimed to have“near-ambient superconductivity”[Dasenbrock-Gammon et al.,Nature 615,244–250(2023)].If this result could be reproduced by other teams,it would be a major scientific breakthrough.Here,we report our results of transport and structure measurements on a material prepared using the same method as reported by Dasenbrock-Gammon et al.Our x-ray diffraction measurements indicate that the obtained sample contains three substances:the facecentered-cubic(FCC)-1 phase(Fm-3m)with lattice parameter a=5.03Å,the FCC-2 phase(Fm-3m)with a lattice parameter a=4.755Å,and Lu metal.The two FCC phases are identical to the those reported in the so-called near-ambient superconductor.However,we find from our resistance measurements in the temperature range from 300 K down to 4 K and the pressure range 0.9–3.4 GPa and our magnetic susceptibility measurements in the pressure range 0.8–3.3 GPa and the temperature range down to 100 K that the samples show no evidence of superconductivity.We also use a laser heating technique to heat a sample to 1800 XC and find no superconductivity in the produced dark blue material below 6.5 GPa.In addition,both samples remain dark blue in color in the pressure range investigated. | Shu Cai Jing Guo Haiyun Shu Liuxiang Yang Pengyu Wang Yazhou Zhou Jinyu Zhao Jinyu Han Qi Wu Wenge Yang Tao Xiang Ho-kwang Mao Liling Sun | 2023 | Matter and Radiation at Extremes2023，8，4： | 0 |
| 14 | Pedestrian wind flow prediction using spatial-frequency generative adversarial network显示文摘Pedestrian wind flow is a critical factor in designing livable residential environments under growing complex urban conditions.Predicting pedestrian wind flow during the early design stages is essential but currently suffers from inefficiencies in numerical simulations.Deep learning,particularly generative adversarial networks(GAN),has been increasingly adopted as an alternative method to provide efficient prediction of pedestrian wind flow.However,existing GAN-based wind flow prediction schemes have limitations due to the lack of considering the spatial and frequency characteristics of wind flow images.This study proposes a novel approach termed SFGAN,which embeds spatial and frequency characteristics to enhance pedestrian wind flow prediction.In the spatial domain,Gaussian blur is employed to decompose wind flow into components containing wind speed and distinguished flow edges,which are used as the embedded spatial characteristics.Detailed information of wind flow is obtained through discrete wavelet transformation and used as the embedded frequency characteristics.These spatial and frequency characteristics of wind flow are jointly utilized to enforce consistency between the predicted wind flow and ground truth during the training phase,thereby leading to enhanced predictions.Experimental results demonstrate that SFGAN clearly improves wind flow prediction,reducing Wind_MAE,Wind_RMSE and the Fréchet Inception Distance(FID)score by 5.35%,6.52%and 12.30%,compared to the previous best method,respectively.We also analyze the effectiveness of incorporating the spatial and frequency characteristics of wind flow in predicting pedestrian wind flow.SFGAN reduces errors in predicting wind flow at large error intervals and performs well in wake regions and regions surrounding buildings.The enhanced predictions provide a better understanding of performance variability,bringing insights at the early design stage to improve pedestrian wind comfort.The proposed spatial-frequency loss term is general and can be flexibly integrated with other generative models to enhance performance with only a slight computational cost. | Pengyue Wang Maozu Guo Yingeng Cao Shimeng Hao Xiaoping Zhou Lingling Zhao | 2024 | Building Simulation2024，17，2： | 0 |
| 15 | Transaldolase inhibits CD36 expression by modulating glutathione-p38 signaling,exerting protective effects against macrophage foam cell formation显示文摘In atherosclerosis,macrophage-derived foam cell formation is considered to be a hallmark of the pathological process;this occurs via the uptake of modified lipoproteins.In the present study,we aim to determine the role of transaldolase in foam cell formation and atherogenesis and reveal the mechanisms underlying its role.Bone marrow-derived macrophages(BMDMs)isolated from mice successfully form foam cells after treatment with oxidized low-density lipoprotein(80μg/mL).Elevated transaldolase levels in the foam cell model are assessed by quantitative polymerase chain reaction and western blot analysis.Transaldolase overexpression and knockdown in BMDMs are achieved via plasmid transfection and small interfering RNA technology,respectively.We find that transaldolase overexpression effectively attenuates,whereas transaldolase knockdown accelerates,macrophagederived foam cell formation through the inhibition or activation of cholesterol uptake mediated by the scavenger receptor cluster of differentiation 36(CD36)in a p38 mitogen-activated protein kinase(MAPK)signaling-dependent manner.Transaldolase-mediated glutathione(GSH)homeostasis is identified as the upstream regulator of p38 MAPK-mediated CD36-dependent cholesterol uptake in BMDMs.Transaldolase upregulates GSH production,thereby suppressing p38 activity and reducing the CD36 level,ultimately preventing foam cell formation and atherosclerosis.Thus,our findings indicate that the transaldolase-GSH-p38-CD36 axis may represent a promising therapeutic target for atherosclerosis. | Chengyi Li Zihao Song Pengyue Gao Wei Duan Xiu Liu Sijia Liang Quan Gong Jiawei Guo | 2023 | Acta Biochimica et Biophysica Sinica2023，55，9： | 0 |
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