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| 1 | Numerical simulation and experimental verification on downwash air flow of six-rotor agricultural unmanned aerial vehicle in hover显示文摘Recently,multi-rotor unmanned aerial vehicle(UAV)becomes more and more significantly irreplaceable in the field of plant protection against diseases,pests and weeds of crops.The easy takeoff and landing performance,hover function and high spraying efficiency of UAV are urgently required to spray pesticide for crop timely and effectively,especially in dispersed plots and hilly mountains.In such situations,the current researches about UAV spray application mainly focus on studying the influence of the UAV spraying parameters on the droplet deposition,such as operation height,operation velocity and wind velocity.The deposition and distribution of pesticide droplets on crops which depends on installation position of nozzle and airflow distribution characteristics of UAV are directly related to the control effect of pesticide and crop growth in different growth periods.As a preliminary step,this study focuses on the dynamic development law and distribution characteristics of the downwash air flow for the SLK-5 six-rotor agricultural UAV.Based on compressible Reynolds-averaged Navier-Stokes(RANS)equations with an RNG k-εturbulence model and dynamic mesh technology,the efficient three-dimensional computational fluid dynamics(CFD)method was established to analyze the flow field distribution characteristics of UAV in hover.Then the unsteady interaction flow field of the wing was investigated in detail.The downwash wind speed of the marked points for the SLK-5 UAV in hover was also tested by weather tracker.It was found that the maximum velocity value of the downwash flow was close to 10 m/s;the z-direction velocity was the main body of the wind velocity in the downwash airflow,and the comparison of the wind velocity experiment test and simulation showed that the relative error was less than 12%between the experimental and simulated values of the z-direction velocity at the marked points.Then the flow characteristics of the longitudinal and cross section were analyzed in detail,the results obtained can be used as a reference for drift and sedimentation studies for multi-rotor unmanned aerial vehicle. | Yang Fengbo Xue Xinyu Zhang Ling Sun Zhu | 2017 | International Journal of Agricultural and Biological Engineering2017,10,4: | 28 |
| 2 | Bone marrow mesenchymal stem cell therapy in ischemic stroke: mechanisms of action and treatment optimization strategies显示文摘Animal and clinical studies have confirmed the therapeutic effect of bone marrow mesenchymal stem cells on cerebral ischemia, but their mechanisms of action remain poorly understood. Here, we summarize the transplantation approaches, directional migration, differentiation, replacement, neural circuit reconstruction,angiogenesis, neurotrophic factor secretion, apoptosis, immunomodulation, multiple mechanisms of action,and optimization strategies for bone marrow mesenchymal stem cells in the treatment of ischemic stroke.We also explore the safety of bone marrow mesenchymal stem cell transplantation and conclude that bone marrow mesenchymal stem cell transplantation is an important direction for future treatment of cerebral ischemia. Determining the optimal timing and dose for the transplantation are important directions for future research. | Guihong Li Fengbo Yu Ting Lei Haijun Gao Peiwen Li Yuxue Sun Haiyan Huang Qingchun Mu | 2016 | Neural Regeneration Research2016,11,6: | 22 |
| 3 | Vehicle Active Steering Control Research Based on Two-DOF Robust Internal Model Control显示文摘Because of vehicle's external disturbances and model uncertainties,robust control algorithms have obtained popularity in vehicle stability control.The robust control usually gives up performance in order to guarantee the robustness of the control algorithm,therefore an improved robust internal model control(IMC) algorithm blending model tracking and internal model control is put forward for active steering system in order to reach high performance of yaw rate tracking with certain robustness.The proposed algorithm inherits the good model tracking ability of the IMC control and guarantees robustness to model uncertainties.In order to separate the design process of model tracking from the robustness design process,the improved 2 degree of freedom(DOF) robust internal model controller structure is given from the standard Youla parameterization.Simulations of double lane change maneuver and those of crosswind disturbances are conducted for evaluating the robust control algorithm,on the basis of a nonlinear vehicle simulation model with a magic tyre model.Results show that the established 2-DOF robust IMC method has better model tracking ability and a guaranteed level of robustness and robust performance,which can enhance the vehicle stability and handling,regardless of variations of the vehicle model parameters and the external crosswind interferences.Contradiction between performance and robustness of active steering control algorithm is solved and higher control performance with certain robustness to model uncertainties is obtained. | WU Jian LIU Yahui WANG Fengbo BAO Chunjiang SUN Qun ZHAO Youqun | 2016 | Chinese Journal of Mechanical Engineering2016,29,4: | 11 |
| 4 | Research progress in ZnO single-crystal:growth, scientific understanding, and device applications显示文摘Zinc oxide,a wide band-gap semiconductor,has shown extensive potential applications in high-efficiency semiconductor photoelectronic devices,semiconductor photocatalysis,and diluted magnetic semiconductors.Due to the undisputed lattice integrity,ZnO single crystals are essential for the fabrication of high-quality ZnO-based photoelectronic devices,and also believed to be ideal research subjects for understanding the underlying mechanisms of semiconductor photocatalysis and diluted magnetic semiconductors.This review,which is organized in two main parts,introduces the recent progress in growth,basic characterization,and device development of ZnO single crystals,and some related works in our group.The first part begins from the growth of ZnO single crystal,and summarizes the fundamental and applied investigations based on ZnO single crystals.These works are composed of the fabrication of homoepitaxial ZnO-based photoelectronic devices,the research on the photocatalysis mechanism,and dilute magnetic mechanism.The second part describes the fabrication of highly thermostable n-type ZnO with high mobility and high electron concentration through intentional doping.More importantly,in this part,a conceptual approach for fabricating highly thermostable p-type ZnO materials with high mobility through an integrated three-step treatment is proposed on the basis of the preliminary research. | Feng Huang Zhang Lin Wenwen Lin Jiye Zhang Kai Ding Yonghao Wang Qinghong Zheng Zhibing Zhan Fengbo Yan Dagui Chen Peiwen Lv Xian Wang | 2014 | Chinese Science Bulletin2014,59,12: | 11 |
| 5 | Assessing changes in wind erosion climatic erosivity in China's dryland region during 1961-2012显示文摘 | YANG Fengbo LU Changhe | 2016 | Journal of Geographical Sciences2016,26,9: | 11 |
| 6 | Intermetallic Compounds in the Banded Structure and Their Effect on Mechanical Properties of Al/Mg Dissimilar Friction Stir Welding Joints显示文摘Dissimilar friction stir welding(FSW) between aluminum and magnesium alloy was performed, using various tool rotational speed(TRS) at a ?xed travel speed, with tool offset to aluminum to investigate the formation of intermetallic compounds(IMCs) in the banded structure(BS) zone and their effect on mechanical properties. Large quantities of IMCs, in the form of alternating bands of particles or lamellae, were found in the BS zone, where drastic material intermixing occurred during FSW. The BS microstructural characters in terms of the morphology of the bands and the quantity and distribution of IMC particles varied with TRS. All welds exhibited brittle fracture mode with their fracture paths propagating mainly in/along the IMCs in the BS. It is shown that these BS microstructural characters have signi?cant effect on the mechanical properties of the joints. Suggestions on tailoring the BS microstructure were proposed for improving the strength of the BS zone and the ?nal mechanical properties of the Al/Mg FSW joints. | Hui Shi Ke Chen Zhiyuan Liang Fengbo Dong Taiwu Yu Xianping Dong Lanting Zhang Aidang Shan | 2017 | Journal of Materials Science & Technology2017,33,4: | 8 |
| 7 | Blind Identification of Underdetermined Mixtures Using Second-Order Cyclostationary Statistics显示文摘 | LU Fengbo ZHANG Bisheng HUANG Zhitao JIANG Wenli | 2013 | Chinese Journal of Electronics2013,22,1: | 5 |
| 8 | Synthesis, bioactivity, action mode and 3D-QSAR of novel anthranilic diamide derivatives显示文摘To study the pesticide effect, action mode, structure-activity relationships (SARs) of anthranilic diamide insecticide and screen highly active pesticides, novel anthranilic diamide derivatives were synthesized.Bioassays indicated that all of the title compounds displayed 100% mortality against diamondback moth and oriental armyworm at 100 mg/L, among which 12 v and 12 w showed 100% insecticidal acitvity at 5 mg/L. Surprisingly compound 12 w exhibited better insecticidal acitvity than commercialized chlorantraniliprole against Pyrausta nubilalis (0.1 mg/L) and Cnaphalocrocis Medinalis (2 mg/L). 3 D-QSAR and SARs statistical analysis revealed that title compounds with R^2 fixed as methoxy had the highest probability possessing high activity. The calcium fluorescence measurements on neurons revealed that E series compounds containing pyrazinyl may have a molecular target different from caffeine on ryanodine receptors rather than the voltage-gated calcium channel present on cytomembran. | Weijie Liu Jiao Li Kai He Fangfang Huang Yi Ma Yuxin Li Qingshan Li Fengbo Xu | 2019 | Chinese Chemical Letters2019,30,2: | 4 |
| 9 | Effects of Rice-Fish Co-culture on Oxygen Consumption in Intensive Aquaculture Pond显示文摘Rice-fish co-culture has gained increasing attention to remediate the negative environmental impacts induced by intensive aquaculture. However, the effect of rice-fish co-culture on oxygen depletion has rarely been investigated. We constructed a rice-fish co-culture system in yellow catfish(Pelteobagrus fulvidraco) and freshwater shrimp(Macrobrachium nipponense) ponds using a new high-stalk rice variety, and conducted a field experiment to investigate the effect of rice-fish co-culture on water parameters and oxygen consumption. The results showed that rice-fish co-culture reduced the nutrients(total nitrogen, ammonia-N, total phosphorous and potassium) and the dissolved oxygen content in fish and shrimp ponds. However, they showed similar seasonal change of dissolved oxygen in the water of fish and shrimp ponds. Rice-fish co-culture reduced the total amount of oxygen consumption and optimized the oxygen consumption structure in pond. The respiration rates in water and sediment were significantly reduced by 66.1% and 31.7% in the catfish pond, and 64.4% and 38.7% in the shrimp pond, respectively, by additional rice cultivation. Rice-fish co-culture decreased the proportions of respiration in sediment and water, and increased the proportion of fish respiration. These results suggest that rice-fish co-culture is an efficient way to reduce hypoxia in intensive culture pond. | LI Fengbo SUN Zhiping QI Hangying ZHOU Xiyue XU Chunchun WU Dianxin FANG Fuping FENG Jinfei ZHANG Ning | 2019 | Rice science2019,26,1: | 4 |
| 10 | Impact of Rice-Catfish/Shrimp Co-culture on Nutrients Fluxes Across Sediment-Water Interface in Intensive Aquaculture Ponds显示文摘Exchange of nitrogen and phosphorus across sediment-water interface plays an important role in the management of nutrient recycling in the aquaculture pond. In this study, a plot experiment was conducted to study the effect of rice-catfish/shrimp co-culture on the micro-profile of oxygen (O2), pH and nutrient exchange across sediment-water interface in the intensive culture ponds. The results showed that rice-catfish co-culture increased the concentration and penetrating depth of O2, but decreased the pH value across the sediment-water interface, compared with catfish monoculture. Additional rice cultivation significantly reduced the flux rates of ammonium (NH4+) and nitrate (NO3-) across sediment-water interface in the catfish and shrimp ponds. The flux rates of NO2 - and soluble phosphorus (PO43-) showed no significant difference between rice-catfish/shrimp co-culture ponds and catfish/shrimp monoculture ponds. Rice only affected the dissolved inorganic nitrogen and phosphorus fractions in the sediment. The concentrations of NH4 + were significantly lower in the sediment of co-culture ponds than in the monoculture ponds. Additional rice cultivation also significantly reduced the content and percentage of dissolved inorganic phosphorus in the sediment of catfish ponds. | LIU Yaobin QIN Lin LI Fengbo ZHOU Xiyue XU Chunchun JI Long CHEN Zhongdu FENG Jinfei FANG Fuping | 2019 | Rice science2019,26,6: | 4 |
| 11 | Short-term Prediction of Ionospheric TEC Based on ARIMA Model显示文摘In order to achieve high short-term prediction accuracy of ionospheric TEC,first,we transform a seasonal time series for ionospheric Total Electron Content (TEC) into a stationary time series by seasonal differences and regular differences with a full consideration of the Multiplicative Seasonal model.Next,we use the Autoregressive Integrated Moving Average (ARIMA) model taken from time series analysis theory for modeling the stationary TEC values to predict the TEC series.Using TEC data from 2008 to 2012 provided by the Center for Orbit Determination in Europe (CODE) as sample data,we analyzed the precision of this method for prediction of ionospheric TEC values which vary from high to low latitudes during both quiet and active ionospheric periods.The effect of the TEC sample’s length on the predicted accuracy is analyzed,too.Results from numerical experiments show that during the ionospheric quiet period the average relative prediction accuracy for a six day time span reaches up to 83.3% with average prediction residual errors of about 0.18±1.9 TECu.During ionospheric active periods it changes to 86.6% with an average prediction residual error of about 0.69±2.6 TECu.For the quiet periods,above 90% of predicted residual is less than ±3 TECu while during active periods,it is only about 81%.The two periods show that that the higher the latitude,the higher the absolute precision,and the lower the predicted relative accuracy.In addition,the results show that prediction accuracy will improve with an increase of the TEC sample sequences length,but it will gradually reduce if the length exceeds the optimal length,about 30 days.On the other hand,with the same TEC sample,as the predicted days increase,the predictive accuracy decreases.Athough the predictive accuracy is not apparent at the beginning,it will be significantly reduced after 30 days. | Xiaohong ZHANG Xiaodong REN Fengbo WU Qi LU | 2019 | Journal of Geodesy and Geoinformation Science2019,2,1: | 4 |
| 12 | Atomic and electronic basis for the serrations of refractory high-entropy alloys显示文摘Refractory high-entropy alloys present attractive mechanical properties,i.e.,high yield strength and fracture toughness,making them potential candidates for structural applications.Understandings of atomic and electronic interactions are important to reveal the origins for the formation of high-entropy alloys and their structure−dominated mechanical properties,thus enabling the development of a predictive approach for rapidly designing advanced materials.Here,we report the atomic and electronic basis for the valence−electron-concentration-categorized principles and the observed serration behavior in high-entropy alloys and highentropy metallic glass,including MoNbTaW,MoNbVW,MoTaVW,HfNbTiZr,and Vitreloy-1 MG(Zr_(41)Ti_(14)Cu_(12.5)Ni_(10)Be_(22.5)).We find that the yield strengths of high-entropy alloys and high-entropy metallic glass are a power-law function of the electron-work function,which is dominated by local atomic arrangements.Further,a reliance on the bonding-charge density provides a groundbreaking insight into the nature of loosely bonded spots in materials.The presence of strongly bonded clusters and weakly bonded glue atoms imply a serrated deformation of high-entropy alloys,resulting in intermittent avalanches of defects movement. | William Yi Wang Shun Li Shang Yi Wang Fengbo Han Kristopher A.Darling Yidong Wu Xie Xie Oleg N.Senkov Jinshan Li Xi Dong Hui Karin A.Dahmen Peter K.Liaw Laszlo J.Kecskes Zi-Kui Liu | 2017 | npj Computational Materials2017,,1: | 3 |
| 13 | Cucurbit[10]uril-based chemistry显示文摘Cucurbit[n]urils(CB[n]s,n = 5-8,10,13-15) have been proven to be an interesting macrocyclic family with their distinctive molecular recognition properties and fascinating applications in fields such as catalysis,supramolecular materials, drug delivery and biological systems. With the biggest cavity in the CB[n]s family, CB[10] shows its unique molecular recognition properties that are rather distinctive from other CB[n]s. In this review, we summarize the progresses in CB[10]-based chemistry since CB[10] was first reported as CB[10] CB[5] complex in 2001. Purification, molecular recognition and supramolecular assembly of CB[10] will be described and an outlook will be given for further exploration of CB[10]-based chemistry. | Xiran Yang Fengbo Liu Zhiyong Zhao Feng Liang Haijun Zhang Simin Liu | 2018 | Chinese Chemical Letters2018,29,11: | 2 |
| 14 | Synthesis,bioactivities and 3D-QSAR of novel avermectin B2a aglycon derivatives显示文摘Fourteen avermectin B2 a aglycon derivatives were designed and synthesized after removing the oleandrose disaccharide of avermectin B2 a.Their structures were characterized by’H NMR,13 C NMR,HMRS.Preliminary bioassays indicated that these compounds exhibited good insecticidal activity against diamondback moth at 200 mg/L,with mortality no less than 90%.Compounds 10 b,12 a,12 c,17 demonstrated good acaricidal activity against the adult mites,larvae,and good inhibition rate of hatching to mite eggs of Tetranychus cinnabarinus.Compounds 5,10 b,10 c exhibited excellent fungicidal activity against fourteen fungal pathogens in vitro.3 D-QSAR analysis showed that the fungicidal activity of avermectin B2 a aglycon derivatives would be increased when a negatively charged and bulky group was introduced at 13-position,which will be instructive for the further modification of avermectin B2 aaglycon. | Fangfang Huang Huan Ling Jiao Li Sen Lu Weijie Liu Qingshan Li Fengbo Xu | 2020 | Chinese Chemical Letters2020,31,1: | 2 |
| 15 | Carbon dioxide reforming of methane over carbonaceous catalyst in a plug flow reactor显示文摘 | Guo Fengbo Zhang Yongfa | 2013 | Applied Mechanics and Materials2013,291,: | 1 |
| 16 | Nanoporous photocatalysts developed through heat-driven stacking of graphitic carbon nitride nanosheets 显示文摘 | Huang Zhijun Li Fengbo Chen Bingfeng | 2015 | The Royal Society of Chemistry2015,5,14: | 1 |
| 17 | Numerical Investigation of a Turbine Stator with Nonaxisymmetric Endwall Profiling显示文摘Nonaxisymmetric endwall is an effective method to reduce secondary loss and improve aerodynamic performance.In this paper,a nonaxisymmetric endwall automated optimization process based on the nonuniform rational B-spline surface(NURBS)technique was proposed.This technique was applied for the aerodynamic optimization of the turbine stator shroud endwall to reduce total pressure loss and secondary kinetic energy.The flow fields of the datum endwall design(Datum)and optimization endwall design(Opt)were investigated and compared.Quantitative loss analysis was performed with a loss breakdown method.The entropy generation was classified as profile loss,secondary loss and trailing edge loss,all of which were reduced.The secondary loss was much smaller than the profile loss.In general,the blade row total entropy loss decreased by 11.7%.The results showed that the Opt design reduced total pressure loss and coefficient of secondary kinetic energy by 11.1%and 11.0%,respectively.The decrease in secondary kinetic energy could be attributed to the reduction in the horseshoe vortex and the reduced transverse pressure gradient.When the outlet Mach numbers and inlet incidence angles vary,the performance of the profiled endwall design was always better than the datum design.In the turbine stage simulation,the efficiency was increased by 0.28%with nonaxisymmetric endwall. | LIU Wei WANG Songtao WEN Fengbo | 2022 | Journal of Thermal Science2022,31,5: | 1 |
| 18 | Research and experiments on cutting windows by water-jetting techniques显示文摘 | LIN Fengbo SHANG Qingchun XUE Ling | 2002 | Petroleum Drilling Techniques2002,30,5: | 1 |
| 19 | 显示文摘 | FengBo(冯波)etal | | 功能材料0,,: | 1 |
| 20 | Effect of Leading-Edge Optimization on the Loss Characteristics in a Low-Pressure Turbine Linear Cascade显示文摘This paper presents a numerical study on the aerodynamics loss reduction characteristics after the leading-edge(LE) optimization in a low-pressure turbine linear cascade. The LE was optimized with a simple and practical method of 'Class Function/Shape Function Transformation Technique'(CST). The simulation conditions, covering the whole working range, were independently determined by incidence, Reynolds number and Mach number. Quantitative loss analyses were carried out with a loss breakdown method based on volumetric integration of entropy production rates. To understand the reason of loss reduction, the local sources at different operating points were identified with entropy production rates. The results showed that LE optimization with the CST method played a positive role in decreasing the total losses, and the working range with lower loss was extended. The profile loss and the endwall loss were significantly reduced by the LE optimization, which were also verified to be the major causes of the total loss reduction by loss breakdown. The decrease of profile loss can be attributed to the boundary layer near the LE region and the boundary layer of downstream at off-design incidence. The reduction mostly came from the pressure side at negative incidence, while came from the suction side at the positive incidence. The endwall loss was decreased markedly about 2.5%–5% by the LE optimization at the incidence of-12°, which was 1% at the incidence of 12°. The mechanism for the endwall loss reduction at different incidences was different from each other. At negative incidence, the LE optimization diminished the corner separation vortex on the pressure side. While at positive incidence, the benefits came from three aspects, i.e., reduced suction LE separation bubbles close to the endwall, reduced passage vortex strength, and weakened shear process between passage vortex and trailing shed vortex. The loss of the downstream zone was relatively lower than that of the profile losses and the endwall losses. The effect of LE optimization on the loss of the downstream zone at different conditions was complex and it depended both on the profile boundary layer behavior at the suction trailing edge and on the passage vortex strength. | CUI Tao WANG Songtao TANG Xiaolei WEN Fengbo WANG Zhongqi | 2019 | Journal of Thermal Science2019,28,5: | 1 |