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Numerical analysis of wind effects on aerodynamic characteristics of a ducted fan

Chinese Journal of Aeronautics 2024年第5期37卷 263-280页

作者： yiwei luo Tianfu AI Yuhang HE Bin XU Yuping QIAN Yangjun ZHANG State Key Laboratory of Intelligent Green Vehicle and Mobility School of Vehicle and MobilityTsinghua UniversityBeijing 100084China Key Laboratory of Conveyance and Equipment Ministry of Education East China Jiaotong UniversityNanchang 330013China Vehicle Research Center School of Mechanical EngineeringBeijing Institute of TechnologyBeijing 100081China Beijing Institute of Technology Chongqing Innovation Center Chongqing 401120China

Ducted fans have been extensively used in Unmanned Aerial Vehicles(UAVs)for a variety of missions because of high efficiency,high safety and low ***,as a kind of typical meteorological condition,brings significant aerodynamic interference to the ducted fan,which seriously threatens flight stability and *** this work,the numerical simulation with the Unsteady Reynolds Averaged Navier-Stokes(URANS)method and the sliding mesh technique is performed to evaluate the steady wind *** results show that the wind will lead to serious unsteady effects in the flow field,and the thrust fluctuates at the blade passing frequency of 200 *** the wind speed increases,the rotor thrust increases,the duct thrust decreases,and the total thrust changes *** instability may occur when the wind speed exceeds 8 m/*** the angle of low-speed wind increases,the rotor thrust changes little,the duct thrust increases,and the total thrust *** addition,we figure out that cases with the same crosswind ratio are similar in results,and increasing the rotating speed or fan radius is beneficial to performance improvement in *** findings are essential to the ducted fan design and UAV flight control design for stable and safe operations in wind conditions.

关键词： Unmanned Aerial Vehicle(UAV) Ducted fan Wind effect Thrust fluctuations Computational Fluid Dynamics(CFD)

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Improving the performance of ducted fans for VTOL applications:A review

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Science China(Technological Sciences) 2022年第11期65卷 2521-2541页

作者： QIAN YuPing luo yiwei HU XuanYang ZENG ZeZhi ZHANG YangJun State Key Laboratory of Automotive Safety and Energy School of Vehicle and MobilityTsinghua UniversityBeijing 10o084China

Ducted fans have been widely used in VTOL aircraft due to the high propulsion efficiency and *** efficiency and stability of ducted fans deteriorate in some flight conditions such as hovering in crosswinds or ground *** is necessary to optimize the ducted fan’s structures or apply flow control methods for better adaptions to the typical *** paper presents a detailed review on the ducted fan technology for VTOL applications,especially the methods for improving its efficiency and *** first simplified the classification categories based on boundary conditions instead of flight conditions,since the new classification method covers more situations and is easier to distinguish flow field *** flow characteristics,thrust properties and the optimal structures under different boundary conditions were summarized and ***,new configurations and flow control methods for increasing the efficiency and stability were *** newly proposed integration design between the ducted fan and the motor was emphasized for increasing the power density of the ducted *** review would be helpful to improve our understanding of the relationship between the structures,flow characteristics and thrust properties of ducted fans under different flight conditions,and inspires scientists to design high-efficiency and high-stability propulsion systems with ducted fans.

关键词： ducted fan VTOL figure ofmerit working stability aerodynamic stability

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Recent advances in acid-resistant zeolite T membranes for dehydration of organics

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Chinese Journal of Chemical Engineering 2019年第6期27卷 1449-1457页

作者： yiwei luo Waseem Raza Jianhua Yang Liangqing Li Ying Lu State Key Laboratory of Fine Chemicals School of Chemical EngineeringDalian University of TechnologyDalian 116024China Collaborative Innovation Center of Fine Chemical and Materials Technology School of Chemistry and Chemical EngineeringHuangshan UniversityHuangshan 245041China

Zeolite membranes offer outstanding potentials in separation of many molecular mixtures due to their molecular sieving selectivity and the high thermal and mechanical stability that allow them to operate at harsh *** of durable and high separation performance membranes with lower fabrication and operation cost are highly demanded for industrial applications. Zeolite T membrane possesses good acid-resistance with excellent hydrophilic properties as compared to NaA zeolite membrane and can be extended to industrial organic dehydrations under an acidic environment. In the present review the research advances in development of zeolite T membranes for the dehydration of organic mixtures in acidic conditions are summarized. Especially the low temperature synthesis, and epitaxial growth of the zeolite membrane with high performance are well addressed, besides emphasis is particularly placed on ensemble synthesis of hollow fiber zeolite T membrane module and its future prospects for industrial separations.

关键词： Dehydration of organics Epitaxial growth Zeolite T membrane Membrane pervaporation

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Numerical investigation on unsteady characteristics of ducted fans in ground effect

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中国航空学报:英文版 2023年第9期36卷 79-95页

作者： yiwei luo Tianfu AI Yuhang HE Bin XU Yuping QIAN Yangjun ZHANG State Key Laboratory of Automotive Safety and Energy School of Vehicle and MobilityTsinghua UniversityBeijing 100084China Vehicle Research Center School of Mechanical EngineeringBeijing Institute of TechnologyBeijing 100081China Beijing Institute of Technology Chongqing Innovation Center Chongqing 401120China

Ducted fans are widely used in various applications of Unmanned Aerial Vehicles(UAVs)due to the high efficiency,low noise and high *** unsteady characteristics of ducted fans flying near the ground are significant,which may bring stability *** this paper,the sliding mesh technology is applied and the Unsteady Reynolds Averaged Navier-Stokes(URANS)method is adopted to evaluate the influence of ground on the aerodynamic performance of ducted *** time-averaged results show that the ground leads to the decrease of duct thrust,the increase of rotor thrust and the decrease of total *** transient results show that there exist small-scale stall cells with circumferential movements in ground *** stall cells start to appear at the blade root when the height is 0.8 rotor radius distance,and arise at both the blade root and tip when the height drops to *** is found that the unsteady cells rotate between blade passages with an approximate relative speed of 30%-80%of the fan speed,and lead to thrust fluctuations up to 37%of the total *** results are essential to the flight control design of the ducted fan flying vehicle,to ensure its stability in ground effect.

关键词： Computational fluid dynamics Ducted fan Ground effect Thrust fluctuations UAV

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不同种类及浓度激素处理对3个果桑品种嫩枝扦插的影响

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蚕业科学 2024年第2期50卷 97-105页

作者：袁姜莲李炎罗义维杨超轩亚辉何宁佳资源昆虫高效养殖与利用全国重点实验室西南大学重庆400716

以3个果桑品种一年生半木质化枝条为扦插材料,探讨不同浓度ABT-1、IBA、NAA处理对果桑扦插成活率及生长指标的影响,并采用排队评分法和公式评分法筛选最佳处理条件,旨在为实现果桑优良品种的规模化生产提供技术支持。结果表明:在不同处... 详细信息

以3个果桑品种一年生半木质化枝条为扦插材料,探讨不同浓度ABT-1、IBA、NAA处理对果桑扦插成活率及生长指标的影响,并采用排队评分法和公式评分法筛选最佳处理条件,旨在为实现果桑优良品种的规模化生产提供技术支持。结果表明:在不同处理条件下,3个果桑品种的扦插成活率与对照相比均有明显提高,且在不同品种、激素种类和激素浓度间扦插成活率均存在极显著差异,各因素影响程度由大到小依次为品种、激素浓度、激素种类;总体上,与对照相比,不同激素种类及浓度处理均能显著提高3个果桑品种的新梢重、新梢长、根重、根数、根总长、根直径和根尖数等扦插生长指标。综合评分结果表明,激素对台湾大果桑和红果2号扦插效果的促进作用排序分别为IBA、NAA、ABT-1和IBA、ABT-1、NAA,最佳处理条件都是200 mg/L IBA处理;对台湾四季果桑扦插效果的促进作用排序为ABT-1、NAA、IBA,最佳处理条件为200 mg/L ABT-1处理。在最佳处理条件下,台湾大果桑、台湾四季果桑、红果2号的嫩枝扦插成活率最高,分别可达79%、96%、72%,且3个果桑品种各扦插生长指标均表现良好。该研究为进一步研发高效实用的果桑扦插技术提供了一定的理论指导,也为桑树扦插生根机制的深入研究提供了参考。

关键词：果桑嫩枝扦插成活率生长指标排队评分法公式评分法

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Genome-wide identification and expression analyses of cytochrome P450 genes in mulberry(Morus notabilis)

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Journal of Integrative Plant Biology 2014年第9期56卷 887-901页

作者： Bi Ma yiwei luo Ling Jia Xiwu Qi Qiwei Zeng Zhonghuai Xiang Ningjia He State Key Laboratory of Silkworm Genome Biology Southwest University

Cytochrome P450 S play critical roles in the biosynthesis of physiologically important compounds in *** compounds often act as defense toxins to prevent *** the present study,a total of 174 P450 genes of mulberry（Morus notabilis ***） were identified based on bioinformatics *** mulberry P450 genes were divided into nine clans and 47 families and were found to be expressed in a tissue-preferential *** genes were compared to the P450 genes in Arabidopsis *** CYP80,CYP92,CYP728,CYP733,CYP736,and CYP749 were found to exist in mulberry,and they may play important roles in the biosynthesis of mulberry secondary *** of the functional and metabolic pathways of these genes indicated that mulberry P450 genes may participate in the metabolism of lipids,other secondary metabolites,xenobiotics,amino acids,cofactors,vitamins,terpenoids,and *** results provide a foundation for understanding of the structures and biological functions of mulberry P450 genes.

关键词： Cytochrome P450 metabolism Morus notabilis pathway silkworm

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Confined Ni-In intermetallic alloy nanocatalyst with excellent coking resistance for methane dry reforming

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Journal of Energy Chemistry 2022年第2期31卷 34-47页

作者： Wenming Liu Le Li Sixue Lin yiwei luo Zhenghong Bao Yiru Mao Kongzhai Li Daishe Wu Honggen Peng College of Chemistry Key Laboratory of Poyang Lake Environment and Resource UtilizationMinistry of EducationSchool of Resources Environmental and Chemical EngineeringNanchang UniversityNanchang 330031JiangxiChina Chemical Sciences Divison Oak Ridge National LaboratoryOak RidgeTN 37830USA State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Engineering Kunming University of Science and TechnologyKunming 650093YunnanChina

Carbon dioxide and methane are two main greenhouse gases which are contributed to serious global ***,dry reforming of methane(DRM),a very important reaction developed decades ago,can convert these two major greenhouse gases into value-added syngas or *** main problem retarding its industrialization is the seriously coking formation upon the nickel-based ***,a series of confined indium-nickel(In-Ni)intermetallic alloy nanocatalysts(In_(x)Ni@SiO_(2))have been prepared and displayed superior coking resistance for DRM *** sample containing 0.5 wt.%of In loading(In_(0.5)Ni@SiO_(2))shows the best balance of carbon deposition resistance and DRM reactivity even after 430 h long term stability *** boosted carbon resistance can be ascribed to the confinement of core–shell structure and to the transfer of electrons from Indium to Nickel in In-Ni intermetallic alloys due to the smaller electronegativity of *** the silica shell and the increase of electron cloud density on metallic Ni can weaken the ability of Ni to activate C–H bond and decrease the deep cracking process of *** reaction over the confined InNi intermetallic alloy nanocatalyst was conformed to the Langmuir-Hinshelwood(L-H)mechanism revealed by in situ diffuse reflectance infrared Fourier transform spectroscopy(in-situ DRIFTS).This work provides a guidance to design high performance coking resistance catalysts for methane dry reforming to efficiently utilize these two main greenhouse gases.

关键词： Methane dry reforming InNi intermetallic alloy Confinement Coking resistance Utilization of greenhouse gases

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Abnormal expression of bHLH3 disrupts a flavonoid homeostasis network,causing differences in pigment composition among mulberry fruits

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Horticulture Research 2020年第1期7卷 1725-1743页

作者： Han Li Zhen Yang Qiwei Zeng Shibo Wang yiwei luo Yan Huang Youchao Xin Ningjia He State Key Laboratory of Silkworm Genome Biology Southwest UniversityBeibei400715 ChongqingP.R.China

Mulberry fruits with high concentrations of anthocyanins are favored by consumers because of their good taste,bright color,and high nutritional ***,neither the regulatory mechanism controlling flavonoid biosynthesis in mulberry nor the molecular basis of different mulberry fruit colors is fully ***,we report that a flavonoid homeostasis network comprising activation and feedback regulation mechanisms determines mulberry fruit *** vitro and in vivo assays showed that MYBA-bHLH3-TTG1 regulates the biosynthesis of anthocyanins,while TT2L1 and TT2L2 work with bHLH3 or GL3 and form a MYB-bHLH-WD40(MBW)complex with TTG1 to regulate proanthocyanidin(PA)*** and expression analyses showed that bHLH3 is a key regulator of the regulatory network controlling mulberry fruit coloration and that MYB4 is activated by MBW complexes and participates in negative feedback control of the regulatory network to balance the accumulation of anthocyanins and *** research demonstrates that the interaction between bHLH3 and MYB4 in the homeostasis regulatory network ensures that the fruits accumulate desirable flavonoids and that this network is stable in pigmentrich mulberry ***,the abnormal expression of bHLH3 disrupts the balance of the network and redirects flavonoid metabolic flux in pale-colored fruits,resulting in differences in the levels and proportions of anthocyanins,flavones,and flavonols among differently colored mulberry fruits(red,yellow,and white).The results of our study reveal the molecular basis of the diversity of mulberry fruit colors.

关键词： synthesis colored controlling

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肝移植患儿父母领悟社会支持与家庭功能间的关系:链式中介效应分析

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中华现代护理杂志 2024年第23期30卷 3110-3116页

作者：祝亚宁刘彦慧蒋莹李静高伟冯子航孙颖罗屹惟罗如珍天津中医药大学护理学院天津301617 天津市第一中心医院儿童器官移植科天津300110 天津医科大学护理学院天津300203

目的探讨心理灵活性和二元应对在肝移植患儿父母领悟社会支持与家庭功能间的链式中介效应。方法采用便利抽样法,选取2023年4—10月在天津市第一中心医院儿童器官移植科就诊的320名肝移植患儿父母为研究对象,应用一般资料调查表、领悟社... 详细信息

目的探讨心理灵活性和二元应对在肝移植患儿父母领悟社会支持与家庭功能间的链式中介效应。方法采用便利抽样法,选取2023年4—10月在天津市第一中心医院儿童器官移植科就诊的320名肝移植患儿父母为研究对象,应用一般资料调查表、领悟社会支持量表(PSSS)、接纳与行动问卷第2版(AAQ-Ⅱ)、二元应对量表(DCI)和家庭关怀度指数问卷(APGAR)对研究对象进行调查。采用Pearson相关性分析肝移植患儿父母的领悟社会支持、心理灵活性、二元应对和家庭功能的相关性;采用Amos 26.0软件构建结构方程模型,分析心理灵活性和二元应对在肝移植患儿父母领悟社会支持和家庭功能间的链式中介作用,并采用Bootstrap法进行模型检验。结果本研究共发放问卷320份,回收有效问卷312份,问卷有效回收率为97.50%(312/320)。312名肝移植患儿父母PSSS得分为(59.29±15.64)分,AAQ-Ⅱ得分为(20.35±9.07)分,DCI得分为(124.64±32.65)分,APGAR得分为(6.98±2.74)分。家庭功能与领悟社会支持和二元应对均呈正相关(P<0.01);领悟社会支持与二元应对呈正相关(P<0.01);心理灵活性与家庭功能、领悟社会支持和二元应对均呈负相关(P<0.01)。结构方程模型结果显示心理灵活性和二元应对在领悟社会支持和家庭功能间起链式中介作用且中介效应显著,中介效应值为0.059,心理灵活性与二元应对在领悟社会支持和家庭功能间的链式中介效应占总效应的13.81%(0.059/0.427)。结论肝移植患儿父母领悟社会支持不但直接对其家庭功能产生影响,还通过心理灵活性和二元应对间接影响其家庭功能。

关键词：儿童肝移植父母领悟社会支持心理灵活性二元应对家庭功能中介效应

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Oxidative stress-initiated one-carbon metabolism drives the generation of interleukin-10-producing B cells to resolve pneumonia

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Cellular & Molecular Immunology 2024年第1期21卷 19-32页

作者： Ying Fu Baichao Yu Qi Wang Zhou Lu Hushan Zhang Dan Zhang Feifei luo Ronghua Liu Luman Wang yiwei Chu Department of Immunology School of Basic Medical SciencesShanghai Key Laboratory of Medical Epigenetics and MetabolismInstitutes of Biomedical SciencesFudan UniversityShanghaiChina Zhongshan Hospital Institute of Clinical Science Zhongshan HospitalShanghaiChina Zhaotong Health Vocational College ZhaotongYunnanChina Department of Digestive Diseases Huashan HospitalFudan UniversityShanghaiChina Shanghai Fifth People’s Hospital Fudan UniversityShanghaiChina

The metabolic reprogramming underlying the generation of regulatory B cells during infectious diseases remains *** a Pseudomonas aeruginosa-induced pneumonia model,we reported that IL-10-producing B cells(IL-10+B cells)play a key role in spontaneously resolving infection-mediated *** cytosolic reactive oxygen species(ROS)during inflammation were shown to drive IL-10+B-cell generation by remodeling one-carbon *** of the enzyme serine hydroxymethyltransferase 1(Shmt1)led to inadequate one-carbon metabolism and decreased IL-10+B-cell ***,increased one-carbon flux elevated the levels of the methyl donor S-adenosylmethionine(SAM),altering histone H3 lysine 4 methylation(H3K4me)at the Il10 gene to promote chromatin accessibility and upregulate Il10 expression in B ***,the one-carbon metabolism-associated compound ethacrynic acid(EA)was screened and found to potentially treat infectious pneumonia by boosting IL-10+B-cell ***,these findings reveal that ROS serve as modulators to resolve inflammation by reprogramming one-carbon metabolism pathways in B cells.

关键词： IL-10-producing B cell Reactive oxygen species One-carbon metabolism H3K4me Pneumonia

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