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Experimental and numerical investigation on opposing plasma synthetic jet for drag reduction

Chinese Journal of Aeronautics 2022年第8期35卷 75-91页

作者： Wei XIE Zhenbing LUO Yan ZHOU Wenqiang PENG Qiang LIU Dengpan WANG College of Aerospace Engineering National University of Defense TechnologyChangsha 410073China Beijing Special Engineering Design and Research Institute Beijing 100000China

Experimental and numerical studies are carried out to validate the potential of opposing Plasma Synthetic Jet(PSJ)for drag reduction for a hemisphere.Firstly,flow field changes of opposing PSJ are analyzed by comparing the experimental schlieren images and simulation results in a supersonic free stream of Mach number 3.As PSJ is a kind of unsteady pulsed jet,the shock standoff distance increases initially and then decreases under the control of PSJ,which corresponds to the change of the strength of PSJ.Accordingly,the amount of drag reduction of the hemisphere increases initially and then decreases.It is found that there is a short period of“drag rise”during the formation of PSJ before the drag reduction,which is induced by the generation of normal shock waves and the area difference of the cavity wall of PSJ Actuator(PSJA).Secondly,the effects of five parameters,including exit diameter,discharge energy of PSJA,Mach number,static pressure of incoming flow and angle of attack,on drag reduction of opposing PSJ were studied in detail by using numerical method.It is found that the Maximum Pressure Ratio(MPR)has a significant impact on the average drag reduction for a configuration-determined PSJA.For the configuration selected in this study,the flow field of opposing PSJ shows typical Short Penetration Mode(SPM)in a control cycle of PSJ when the MPR is less than 0.89.However,the flow field shows typical Long Penetration Mode(LPM)at some time when the MPR is bigger than 0.89.Relatively better drag reduction is achieved in this case.

关键词： Drag reduction Opposing jet Parameter study Plasma synthetic jet(PSJ) Supersonic flow

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MRCKα is a novel regulator of prolactin-induced lactogenesis in bovine mammary epithelial cells

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Animal Nutrition 2022年第3期10卷 319-328页

作者： Fang wang Jürgen van Baal Lu Ma Xuejun Gao Jan Dijkstra dengpan Bu State Key Laboratory of Animal Nutrition Institute of Animal ScienceChinese Academy of Agricultural SciencesBeijing100193China Animal Nutrition Group Wageningen University and ResearchWageningen6708WDthe Netherlands College of Animal Science Yangtze UniversityJingzhou434020China Joint Laboratory on Integrated Crop-Tree-Livestock Systems of the Chinese Academy of Agricultural Sciences(CAAS) Ethiopian Institute of Agricultural Research(EIAR)and World Agroforestry Center(ICRAF)Beijing100193China

Myotonic dystrophy-related Cdc42-binding kinase alpha(MRCKα)is an integral component of signaling pathways controlling vital cellular processes,including cytoskeletal reorganization,cell proliferation and cell survival.In this study,we investigated the physiological role of MRCKα in milk protein and fat production in dairy cows,which requires a dynamic and strict organization of the cytoskeletal network in bovine mammary epithelial cells(BMEC).Within a selection of 9 Holstein cows,we found that both mRNA and protein expression of MRCKα in the mammary gland were upregulated during lactation and correlated positively(r>0.89)with the mRNA and protein levels of b-casein.Similar positive correlations(r>0.79)were found in a primary culture of BMEC stimulated with prolactin for 24 h.In these cells,silencing of MRCKα decreased basal b-casein,sterol-regulatory element binding protein(SREBP)-1 and cyclin D1 protein level,phosphorylation of mTOR,triglyceride secretion,cell number and viabilitydwhile overexpression of MRCKα displayed the reversed effect.Notably,silencing of MRCKα completely prevented the stimulatory action of prolactin on the same parameters.These data demonstrate that MRCKα is a critical mediator of prolactin-induced lactogenesis via stimulation of the mTOR/SREBP1/cyclin D1 signaling pathway.

关键词： Myotonic dystrophy-related Cdc42-binding kinase alpha Bovine mammary gland Prolactin Mechanistic target of rapamycin Sterol regulatory element-binding protein-1 Cyclin D1

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Imaging of the Space-time Structure of a Vortex Generator in Supersonic Flow

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Chinese Journal of Aeronautics 2012年第1期25卷 57-63页

作者： wang dengpan XIA Zhixun ZHAO Yuxin wang Bo ZHAO Yanhui Science and Technology on Scramjet Laboratory National University of Defense TechnologyChangsha 410073China

The fine space-time structure of a vortex generator （VG） in supersonic flow is studied with the nanoparticle-based planar laser scattering （NPLS） method in a quiet supersonic wind tunnel. The fine coherent structure at the symmetrical plane of the flow field around the VG is imaged with NPLS. The spatial structure and temporal evolution characteristics of the vortical structure are analyzed, which demonstrate periodic evolution and similar geometry, and the characteristics of rapid movement and slow change. Because the NPLS system yields the flow images at high temporal and spatial resolutions, from these images the position of a large scale structure can be extracted precisely. The position and velocity of the large scale structures can be evaluated with edge detection and correlation algorithms. The shocklet structures induced by vortices are imaged, from which the generation and development of shocklets are discussed in this paper.

关键词： vortex generator nanoparticle-based planar laser scattering vortical structure evolution characteristic shocklet

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Multi-resolution Analysis of Density Fluctuation of Coherent Structures About Supersonic Flow over VG

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Chinese Journal of Aeronautics 2012年第2期25卷 173-181页

作者： wang dengpan ZHAO Yuxin XIA Zhixun wang Qinghua HUANG Xu Science and Technology on Scramjet Laboratory National University of Defense Technology Changsha 410073 China The ThirdInstitute the SecondArtillery Equipment Academy Beijing 100085 China

The density field around a vortex generator （VG） in supersonic flow is studied with a nanoparticle-based planar laser scattering （NPLS） method. Based on the calibration, i.e., the density distribution of the supersonic flow around a wedge, the density field of a supersonic VG is measured. According to movement characteristics of coherent structure in VG’s flow fields and the basic concepts of wavelet, the density fluctuating signals and multi-resolution characteristics of density field images are studied. The multi-resolution characteristics of density fluctuation can be analyzed with wavelet transformation of NPLS images. The wavelet approximate coefficients of density fluctuating signals exhibit their characteristics at different scales, and the corresponding detail coefficients show the difference of diverse layer smooth approximation in some way. Based on 2D wavelet decomposition and reconstruction of density field images, the approximate and detail signals at different scales are studied, and the coherent structures at different scales are extracted and analyzed.

关键词： vortex generator nanoparticle-based planar laser scattering coherent structure density fluctuation multi-resolution analysis

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The background calculation of the filter-fluorescer method

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Nuclear Science and Techniques 2010年第5期21卷 281-284页

作者： wang Dong YANG Gaozhao TANG dengpan Institute of Nuclear Physics and Chemistry China Academy of Engineering Physics Mianyang 621900

For the measurement of X-ray energy spectrum with filter-fluorescer method,the high energy tail at the rearward of response function is the main source of background.There are,traditionally,two techniques for measuring the background contributions:the same element Z for the fluorescer and filter,or the same element Z?1 for them.Using the formula of fluorescence intensity,and the elemental combinations of cobalt and iron,the backgrounds which the two techniques provide and the real one for measuring black-body radiation at equilibrium temperature of 7×106 K,were calculated.The results show that the Co-Co combination for the filter-fluorescer spectrometer can achieve better effect.A semi-quantitative analysis for the calculation results is discussed.

关键词：计算结果过滤器荧光剂后台测量方法相同元素半定量分析响应函数

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Structural design and parameter determination for fluted-roller fertilizer applicator

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International Journal of Agricultural and Biological Engineering 2020年第2期13卷 101-110页

作者： Shan Zeng Yipeng Tan Yu wang Xiwen Luo Lamei Yao dengpan Huang Zewen Mo Key Laboratory of Key Technology on Agricultural Machine and Equipment Ministry of EducationSouth China Agricultural UniversityGuangzhou 510642China College of Engineering South China Agricultural UniversityGuangzhou 510642China

The instability of the motion layer of fertilizer particle influences the precision and the accuracy of the amount of fertilizer application in the working process of fluted-roller fertilizer applicator.The characteristics of the motion layer were investigated,and a systematic scheme was proposed for designing the structures of fertilizer-filling cavity,fertilizer-filling surface and fertilizer-delivery cavity.The key parameters of the structure were studied by discrete element method.It was figured out that to ensure the smooth operation of fertilizer applicator,the fertilizer-filling angle was 105°,fertilizer-contact angle should be large than 100°,and the fertilizer-resistance angle should be smaller than 35°.Moreover,the stability of fertilizer motion morphology was investigated to verify the design.The results showed that when the roll rotational speed was larger than 120 deg/s,compared with the conventional design the CV of the amount of fertilizer application was reduced from 1.5%-3.5%to 0.5%-1.0%,and the accuracy of the fertilizer discharge was improved with the square of the correlation coefficient between the amount of fertilizer application and the roll rotational speed was larger than 0.999.It was deduced from the results that the precision and accuracy of the amount of fertilizer application are improved via eliminating the driving layer and enhancing the stable filling and conveying of the forced layer.

关键词： fertilizer applicator fluted-roller precision fertilization structural design structural parameters

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Defend Against Adversarial Samples by Using Perceptual Hash

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Computers, Materials & Continua 2020年第3期62卷 1365-1386页

作者： Changrui Liu dengpan Ye Yueyun Shang Shunzhi Jiang Shiyu Li Yuan Mei Liqiang wang Key Laboratory of Aerospace Information Security and Trusted Computing Ministry of EducationSchool of Cyber Science and EngineeringWuhan UniversityWuhan430072China School of Mathematics and Statistics South Central University for NationalitiesWuhan430074China University of Central Florida 4000 Central Florida Blvd.OrlandoFlorida32816USA

Image classifiers that based on Deep Neural Networks(DNNs)have been proved to be easily fooled by well-designed perturbations.Previous defense methods have the limitations of requiring expensive computation or reducing the accuracy of the image classifiers.In this paper,we propose a novel defense method which based on perceptual hash.Our main goal is to destroy the process of perturbations generation by comparing the similarities of images thus achieve the purpose of defense.To verify our idea,we defended against two main attack methods(a white-box attack and a black-box attack)in different DNN-based image classifiers and show that,after using our defense method,the attack-success-rate for all DNN-based image classifiers decreases significantly.More specifically,for the white-box attack,the attack-success-rate is reduced by an average of 36.3%.For the black-box attack,the average attack-success-rate of targeted attack and non-targeted attack has been reduced by 72.8%and 76.7%respectively.The proposed method is a simple and effective defense method and provides a new way to defend against adversarial samples.

关键词： Image classifiers deep neural networks adversarial samples attack defense perceptual hash image similarity

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Identification of Potential Therapeutic Targets of Alzheimer's Disease By Weighted Gene Co-Expression Network Analysis

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Chinese Medical Sciences Journal 2020年第4期35卷 330-341页

作者： Fan Zhang Siran Zhong Siman Yang Yuting Wei Jingjing wang Jinlan Huang dengpan Wu Zhenguo Zhong Pharmacy School Guangxi University of Chinese MedicineNanning 530200China Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy Pharmacy SchoolXuzhou Medical UniversityXuzhouJiangsu 221004China

Objective Alzheimer's disease(AD)is the most common cause of dementia.The pathophysiology of the disease mostly remains unearthed,thereby challenging drug development for AD.This study aims to screen high throughput gene expression data using weighted co-expression network analysis(WGCNA)to explore the potential therapeutic targets.Methods The dataset of GSE36980 was obtained from the Gene Expression Omnibus(GEO)database.Normalization,quality control,filtration,and soft-threshold calculation were carried out before clustering the co-expressed genes into different modules.Furthermore,the correlation coefiidents between the modules and clinical traits were computed to identify the key modules.Gene ontology and pathway enrichment analyses were performed on the key module genes.The STRING database was used to construct the protein-protein interaction(PPI)networks,which were further analyzed by Cytoscape app(MCODE).Finally,validation of hub genes was conducted by external GEO datasets of GSE 1297 and GSE 28146.Results Co-expressed genes were clustered into 27 modules,among which 6 modules were identified as the key module relating to AD occurrence.These key modules are primarily involved in chemical synaptic transmission(G0:0007268),the tricarboxylic acid(TCA)cycle and respiratory electron transport(R-HSA-1428517).WDR47,OXCT1,C3orfl4,ATP6V1A,SLC25A14,NAPB were found as the hub genes and their expression were validated by external datasets.Conclusions Through modules co-expression network analyses and PPI network analyses,we identified the hub genes of AD,including WDR47,0XCT1,C3orfl4i ATP6V1A,SLC25A14 and NAPB.Among them,three hub genes(ATP6V1A,SLC25A14,OXCT1)might contribute to AD pathogenesis through pathway of TCA cycle.

关键词： bioinformatics analysis Alzheimer's disease Tricarboxylic acid(TCA)cycle weighted gene co-expression network analysis OXCT1 ATP6V1A

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Energy partitioning and environmental influence factors in different vegetation types in the GEWEX Asian Monsoon Experiment

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Frontiers of Earth Science 2014年第4期8卷 582-594页

作者： Fengshan LIU Fulu TAO Shenggong LI Shuai ZHANG dengpan XIAO Meng wang Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China Graduate University of Chinese Academy of Sciences Beijing 100049 China Institute of Geographical Sciences Hebei Academy of Sciences Shijiazhuang 050011 China

Environmental influences upon energy balance in areas of different vegetation types （i.e., forest at Kog-Ma in Thailand and at Yakutsk in Russia, grassland at Amdo in Chinese Tibet and at Arvaikheer in Mongolia, and mixed farmland at Tak in Thailand） in the GEWEX Asian Monsoon Experiment were investigated. The sites we investigated are geographically and climatologically different; and consequently had quite large variations in temperature （T）, water vapor pressure deficit （VPD）, soil moisture （SM）, and precipitation （PPT）. During May- October, the net radiation flux （Rn）（in W·m^-2） was 406.21 at Tak, 365.57 at Kog-Ma, 390.97 at Amdo, 316.65 at Arvaikheer, and 287.10 at Yakutsk. During the growing period, the Rn partitioned into latent heat flux （2E/Rn） was greater than that partitioned into sensible heat flux （H/Rn） at Tak and at Kog-Ma. In contrast, 2E/Rn was lower than H/Rn at Arvaikheer, H/Rn was less than 2E/Rn between DOY 149 and DOY 270 at Amdo, and between DOY 165 and DOY 235 at Yakutsk. The R, partitioned into ground heat flux was generally less than 0.15. The short-wave albedo was 0.12, 0.18, and 0.20 at the forest, mixed land, and grass sites, respectively. At an hourly scale, energy partitions had no correlation with environmental factors, based on average summer half- hourly values. At a seasonal scale energy partitions were linearly correlated （usually p 〈 0.05） with T, VPD, and SM. The 2E/Rn increased with increases in SM, T, and VPD at forest areas. At mixed farmlands, ）λE/Rn generally had positive correlations with SM, T, and VPD, but was restrained at extremely high values of VPD and T. At grasslands, λE/Rn was enhanced with increases of SM and T, but was decreased with VPD.

关键词： energy balance vegetation type netradiation latent heat flux sensible heat flux short-wavealbedo GEWEX Asian Monsoon Experiment

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Impact of thermal time shift on wheat phenology and yield under warming climate in the Huang-Huai-Hai Plain, China

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Frontiers of Earth Science 2017年第1期11卷 148-155页

作者： dengpan XIAO Yongqing QI Zhiqiang LI Rende wang Juana P. MOIWO Fengshan LIU Institute of Geographical Sciences Hebei Academy of Sciences Shijiazhuang 050011 China Key Laboratory for Agricultural Water Resources Hebei Key Laboratory for Agricultural Water-Saving Center for Agricultural Resource Research Institute of Genetics and Development Biology Chinese Academy of Sciences Shijiazhnang 050021 China Department of Agricultural Engineering School of Technology Njala University Freetown Sierra Leone Juncao Research Institute Fujian Agriculture and Forestry University Fuzhou 350002 China

Given climate change can potentially influence crop phenology and subsequent yield, an investigation of relevant adaptation measures could increase the understanding and mitigation of these responses in the future. In this study, field observations at 10 stations in the Huang- Huai-Hai Plain of China （HHHP） are used in combination with the Agricultural Production Systems Simulator （APSIM）-Wheat model to determine the effect of thermal time shift on the phenology and potential yield of wheat from 1981-2009. Warming climate speeds up winter wheat development and thereby decreases the duration of the wheat growth period. However, APSIM-Wheat model simulation suggests prolongation of the period from flowering to maturity （Gr） of winter wheat by 0.2-0.8 d·10yr^-1 as the number of days by which maturity advances, which is less than that by which flowering advances. Based on computed thermal time of the two critical growth phases of wheat, total thermal time from floral initiation to flowering （TT_floral_initiation） increasesd in seven out of the 10 investigated stations. Altematively, total thermal time from the start of grainfilling to maturity （TT_start grain_fill） increased in all investigated stations, except Laiyang. It is thus concluded that thermal time shift during the past three decades （1981- 2009） prolongs Gr by 0.2-3.0 d·10yr^-1 in the study area. This suggests that an increase in thermal time （TT） of the wheat growth period is critical for mitigating the effect of growth period reduction due to warming climatic condition. Furthermore, climate change reduces potential yield of winter wheat in 80% of the stations by 2.3-58.8 kg·yr^-1. However, thermal time shift （TTS） increases potential yield of winter wheat in most of the stations by 3.0-51.0 Received September 16, 2015; accepted January 24, 2016 kg·yr^-1. It is concluded that wheat cultivars with longer growth periods and higher thermal requirements could mitigate the negative effects of warming climate on crop production in the study area.

关键词： adaptation thermal time shift crop phenology winter wheat warming climate

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