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Prediction of separation flows around a 6:1 prolate spheroid using RANS/LES hybrid approaches

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Acta Mechanica Sinica 2007年第4期23卷 369-382页

作者： zhixiang xiao Yufei zhang jingbo huang Haixin Chen song fu school of aerospace engineering,tsinghua university,beijing 100084,china school of aerospace engineering Tsinghua University Beijing China

This paper presents hybrid Reynolds-averaged Navier-Stokes （RANS） and large-eddy-simulation （LES） methods for the separated flows at high angles of attack around a 6：1 prolate spheroid. The RANS/LES hybrid meth- ods studied in this work include the detached eddy simulation （DES） based on Spalart-Allmaras （S-A）, Menter＇s k-ω shear-stress-transport （SST） and k-o9 with weakly nonlinear eddy viscosity formulation （Wilcox-Durbin＋, WD＋） models and the zonalANS/LES methods based on the SST and WD＋ models. The switch from RANS near the wall to LES in the core flow region is smooth through the implementation of a flow-dependent blending function for the zonal hybrid method. All the hybrid methods are designed to have a RANS mode for the attached flows and have a LES behavior for the separated flows. The main objective of this paper is to apply the hybrid methods for the high Reynolds number separated flows around prolate spheroid at high-incidences. A fourth-order central scheme with fourth-order artificial viscosity is applied for spatial differencing. The fully implicit lower-upper symmetric-Gauss-Seidel with pseudo time sub-iteration is taken as the temporal differentiation. Comparisons with available measurements are carried out for pressure distribution, skin friction, and profiles of velocity, etc. Reasonable agreement with the experiments, accounting for the effect on grids and fundamental turbulence models, is obtained for the separation flows.

关键词： RANS/LES hybrid methods DES Zonal-RANS/LES Weakly nonlinear correction

Structure-regulated fluorine-containing additives to improve the performance of perovskite solar cells

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Nano Research 2024年第7期17卷 6080-6086页

作者： Peiya Chen xiaoman Bi Hao Yan Yingjie Zhao Yihao Liu Zhuo huang Qian xiao Yongpeng Yang Shasha zhang Yiqiang zhang Yanlin song Henan Institute of Advanced Technology College of ChemistrySchool of Materials Science and EngineeringZhengzhou UniversityZhengzhou 450001China Key Laboratory of Green Printing CAS Research/Education Center for Excellence in Molecular SciencesInstitute of ChemistryChinese Academy of Sciences(ICCAS)Beijing Engineering Research Center of Nanomaterials for Green Printing TechnologyNational Laboratory for Molecular Sciences(BNLMS)Beijing 100190China

Perovskite solar cells(PSCs)have seen remarkable progress in recent years,largely attributed to various additives that enhance both efficiency and *** these,fluorine-containing additives have garnered significant interest because of their unique hydrophobic properties,effective defect passivation,and regulation capability on the crystallization ***,a targeted structural approach to design such additives is necessary to further enhance the performance of ***,fluoroalkyl ethylene with different fluoroalkyl chain lengths(CH_(2)CH(CF_(2))nCF_(3),n=3,5,and 7)as liquid additives is used to investigate influences of fluoroalkyl chain lengths on crystallization regulation and defect *** findings indicate that optimizing the quantity of F groups plays a crucial role in regulating the electron cloud distribution within the additive *** optimization fosters strong hydrogen bonds and coordination effects with FA+and uncoordinated Pb^(2+),ultimately enhancing crystal quality and device ***,1H,1H,2H-perfluoro-1-hexene(PF_(3))with the optimal number of F presents the most effective modulation effect.A PSC utilizing PF_(3)achieves an efficiency of 24.05%,and exhibits exceptional stability against humidity and thermal *** work sheds light on the importance of tailored structure designs in additives for achieving high-performance PSCs.

关键词： perovskite solar cells fluorine number additive structure crystallization regulation defect passivation

In situ forming injectable MSC-loaded GelMA hydrogels combined with PD for vascularized sweat gland regeneration

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Military Medical Research 2024年第1期11卷 152-155页

作者： Enhe Jirigala Bin Yao Zhao Li Yi-Jie zhang Chao zhang Li-Ting Liang Fan-Liang zhang Xing-Yu Yuan Xian-Lan Duan Wei song Meng-De zhang Yi Kong xiao-Bing fu Sha huang Research Center for Tissue Repair and Regeneration Medical Innovation Research DepartmentChinese PLA General Hospital and PLA Medical CollegeBeijing 100048China Institute of Basic Medical Research Inner Mongolia Medical UniversityHohhot 010110China Academy of Medical engineering and Translational Medicine Tianjin UniversityTianjin 300072China school of Medicine Nankai UniversityTianjin 300071China

Dear Editor,Three dimensional(3D)bioprinted extracellular matrix(ECM)can be used to provide both biochemical and biophysical cues to direct mesenchymal stem cells(MSCs)differentiation,and then differentiated cells were isolated for implantation in vivo using surgical ***,the reduced cell activity after cell isolation from 3D constructs and low cell retention in injured sites limit its application[1].Methacrylated gelatin(GelMA)hydrogel has the advantage of fast crosslinking,which could resemble complex architectures of tissue construct in vivo[2].Here,we adopted a noninvasive bioprinting procedure to imitate the regenerative microenvironment that could simultaneously direct the sweat gland(SG)and vascular differentiation from MSCs and ultimately promote the replacement of glandular tissue in situ(Fig.1a).

关键词： Sweat gland GelMA In situ niche Cell differentiation Tissue incorporation Vascularization

Overcoming Spatial Constraints in VR:A Survey of Redirected Walking Techniques

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Journal of Computer Science & Technology 2024年第4期39卷 841-870页

作者： Jia-Hong Liu Yang-fu Ren Qi Wen Gan Kui huang Fiona xiao Yu Chen Er-Xia Luo Khang Yeu Tang Yue-Yao fu Cheng-Wei Fan Sen-Zhe Xu song-Hai zhang Academy of Arts and Design Tsinghua UniversityBeijing 100084China Department of Computer Science and Technology Tsinghua UniversityBeijing 100084China College of Computer Technology and Application Qinghai UniversityXining 810016China Zhili College Tsinghua UniversityBeijing 100084China school of Computer Beijing Information Science and Technology UniversityBeijing 100192China Department of Physics Tsinghua UniversityBeijing 100084China school of Computer and Communication engineering University of Science and Technology BeijingBeijing 100083China

As the virtual reality(VR)technology strives to provide immersive and natural user experiences,the challenge of aligning vast virtual environments with limited physical spaces remains *** survey comprehensively explores the advancements in redirected walking(RDW)techniques aimed at overcoming spatial constraints in *** addresses this by subtly manipulating users’physical movements to allow for seamless navigation within constrained *** survey delves into gain perception mechanisms,detailing how slight discrepancies between virtual and real-world movements can be utilized without user awareness,thus extending the effective navigable *** RDW control algorithms for gain-based RDW are analyzed,highlighting their implementation and effectiveness in maintaining immersion and minimizing perceptual ***,novel methods extending beyond traditional gain-based techniques are discussed,showcasing innovative approaches that further refine VR *** practical implications of RDW in enhancing safety and reducing physical collisions in VR environments are underscored,alongside its potential to improve user experience by aligning virtual exploration more closely with natural human behavior *** a thorough review of existing literature and recent advancements,this survey provides a systematic understanding for researchers,developers,and industry *** underscores the importance of RDW in the future of VR,emphasizing RDW's role in making VR more accessible and practical across various applications,from education and training to therapy and *** paper concludes with a forward-looking perspective on the continued evolution and potential of RDW in revolutionizing virtual reality experiences.

关键词： virtual reality(VR) redirected walking(RDW) redirection gain perception

A multicenter prospective study on the management of hepatoblastoma in children:a report from the Chinese Children's Cancer Group

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World Journal of Pediatrics 2024年第6期20卷 590-601页

作者： Meng-Jie Tang xiao-Li Ma Xiang-Ling He Wei-Hua Pan xiao-Hong zhang Sha-Yi Jiang Ju Gao fu Li Wei Yao song Gu Wei-Ling zhang Qiang Zhao Shi-Hao huang Yong-Jun Fang Wei Liu Hui-Zhong Niu Chun-Mei Wang Li-Rong Sun Hui Gao Yun-Peng Dai Shun-Gen huang Zhi-Yong Zhong Xi-Ge Wang Zhong-Rong Li Liang-Chun Yang Ye-Ming Wu Huan-Min Wang Xin Sun xiao-Jun Yuan Department of Pediatric Hematology/Oncology Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of MedicineNo.1665Kongjiang RoadYangpu DistrictShanghai 200092China Medical Oncology Department Pediatric Oncology CenterBeijing Children's HospitalCapital Medical UniversityNational Center for Children's HealthBeijing 100045China Department of Hematology/Oncology Children's Medical CenterHunan Provincial People's HospitalThe First Affiliated Hospital of Hunan Normal UniversityChangsha 41005China Department of Pediatric Surgery Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of MedicineShanghai 200092China Department of Hematology/Oncology Guangzhou Women and Children's Medical CenterNational Children's Medical Center for South Central RegionGuangzhou 510623China Department of Hematology Shanghai Children's HospitalShanghai Jiao Tong UniversityShanghai 200062China Department of Pediatrics West China Second University HospitalSichuan UniversityChengdu 610041China Department of Hematology/Oncology Qilu Children's Hospital of Shandong UniversityJinan 250022China Department of Pediatric Surgery Children's Hospital of Fudan UniversityShanghai 201102China Department of General Surgery Shanghai Children's Medical Center(National Children's Medical Center-Shanghai)Shanghai Jiao Tong University School of MedicineShanghai 200127China Department of Pediatrics Beijing Tongren HospitalCapital Medical UniversityBeijing 100730China Department of Pediatric Oncology Tianjin Medical University Cancer Institute and HospitalTianjin 300060China Department of Hematology/Oncology Children's Hospital of Nanjing Medical UniversityNanjing 210008China Department of Hematology/Oncology Henan Children's HospitalZhengzhou 450018China Department of Pediatric General Surgery Hebei Children's Hospital of Hebei Medical UniversityShijiazhuang City 050031China Children's Hospital the First Affliated Hospital of Zhengzhou UniversityZhengzhou 450052China Department of Paediatric

Background This study aimed to identify survival risk factors in Chinese children with hepatoblastoma(HB)and assess the effectiveness of the new treatment protocol proposed by the Chinese Children's Cancer Group(CCCG)in *** A multicenter,prospective study that included 399 patients with HB from January 2015 to June 2020 was *** demographics,treatment protocols,and other related information were *** regression models and Kaplan-Meier curve methods were *** The 4-year event-free survival(EFS)and overall survival(OS)were 76.9 and 93.5%,*** 4-year EFS rates for the very-low-risk,low-risk,intermediate-risk,and high-risk groups were 100%,91.6%,81.7%,and 51.0%,*** 4-year 0S was 100%,97.3%,94.4%,and 86.8%,*** regression analysis found that age,tumor rupture(R+),and extrahepatic tumor extension(E+)were independent prognostic factors.A total of 299 patients had complete remission,and 19 *** with declining alpha-fetoprotein(AFP)>75%after the first two cycles of neoadjuvant chemotherapy had a better EFS and OS than those≤75%.Conclusions The survival outcome of HB children has dramatically improved since the implementation of CCCG-HB-2016 ***≥8 years,R+,and E+were independent risk factors for *** with a declining AFP>75%after the first two cycles of neoadjuvant chemotherapy had better EFS and OS.

关键词： Alpha-fetoprotein Hepatoblastoma Multicenter Prospective study Survival

Simulation of shock wave buffet and its suppression on an OAT15A supercritical airfoil by IDDES

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Science china(Physics,Mechanics & Astronomy) 2012年第2期55卷 260-271页

作者： huang jingbo xiao zhixiang LIU Jian fu song school of aerospace engineering Tsinghua UniversityBeijing 100084China china Aerodynamics Research&Development Center Mianyang 621000China

In the present paper,extremely unsteady shock wave buffet induced by strong shock wave/boundary-layer interactions (SWBLI) on the upper surface of an OAT15A supercritical airfoil at Mach number of 0.73 and angle of attack of 3.5 degrees is first numerically simulated by IDDES,one of the most advanced RANS/LES hybrid *** results imply that conventional URANS methods are unable to effectively predict the buffet phenomenon on the wing surface;IDDES,which involves more flow physics,predicted buffet *** complex flow phenomena are predicted and demonstrated,such as periodical oscillations of shock wave in the streamwise direction,strong shear layer detached from the shock wave due to SWBLI and plenty of small scale structures broken down by the shear layer instability and in the *** root mean square (RMS) of fluctuating pressure coefficients and streamwise range of shock wave oscillation reasonably agree with experimental ***,two vortex generators (VG) both with an inclination angle of 30 degrees to the main flow directions are mounted in front of the shock wave region on the upper surface to suppress shock wave *** results show that shock wave buffet can be significantly suppressed by VGs,the RMS level of pressure in the buffet region is effectively reduced,and averaged shock wave position is obviously pushed downstream,resulting in increased total lift.

关键词： supercritical airfoil vortex generator shock wave buffet

STUDIES OF SUPERSONIC BASE FLOWS WITH COMPRESSIBLE RANS/LES METHODS

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STUDIES OF SUPERSONIC BASE FLOWS WITH COMPRESSIBLE RANS/LES ...

Massive water production from lunar ilmenite through reaction with endogenous hydrogen

庆祝中国力学学会成立50周年暨中国力学学会学术大会’2007

作者： xiao ZX huang JB zhang YF LI QB CHEN HX fu S~(1)) (school of aerospace engineering,tsinghua university,beijing 100084,china)

For the supersonic air vehicles,the base drag could be amount to 30%～40%of the total *** in the base drag is highly desirable to achieve the overall drag reduction and longer flight *** base drag reduction control methods generally contain two typical forms,*** active and passive *** control methods can reduce the base drag by increasing the base pressure,even achieve thrust,but they need additional devices and complex control *** modifications of base geometry can be considered as effectively passive drag reduction methods which do not alter base structures and induce little additional skin friction drag.

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The Innovation 2024年第5期5卷 47-53,46页

作者： xiao Chen Shiyu Yang Guoxin Chen Wei Xu Lijian song Ao Li Hangboce Yin Weixing Xia Meng Gao Ming Li Haichen Wu Junfeng Cui Lei zhang Lijing miao xiaoxue Shui Weiping Xie Peiling Ke Yongjiang huang Jianfei Sun Bingnan Yao Min Ji Mingliang Xiang Yan zhang Shaofan Zhao Wei Yao Zhigang Zou Mengfei Yang Weihua Wang Juntao Huo Jun-Qiang Wang Haiyang Bai Key Laboratory of Magnetic Materials and Devices Ningbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo 315201China Center of Materials Science and Optoelectronics engineering University of Chinese Academy of SciencesBeijing 100049China Center of Test and Analysis Ningbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo 315201China school of Materials Science and engineering Harbin Institute of TechnologyHarbin 150001China Qian Xuesen Laboratory of Space Technology China Academy of Space Technology(CAST)Beijing 100049China College of engineering and Applied Science Nanjing UniversityNanjing 210093China Institute of Physics Chinese Academy of SciencesBeijing 100049China songshan Lake Materials Laboratory Dongguan 523830China

Finding water resources is a crucial objective of lunar ***,both hydroxyl(OH)and natural water(H2O)have been reported to be scarce on the *** propose a potential method for obtaining water on the Moon through H2O formation via endogenous reactions in lunar regolith(LR),specifically through the reaction FeO/Fe2O3+H/Fe+*** process is demonstrated using LR samples brought back by the Chang’E-5 *** and Fe2O3 are lunar minerals containing Fe ***(H)retained in lunar minerals from the solar wind can be used to produce *** results of this study reveal that 51–76 mg of H2O can be generated from 1 g of LR after melting at temperatures above 1,200 *** amount is10,000 times the naturally occurring OH and H2O on the *** the five primary minerals in LR returned by the Chang’E-5 mission,FeTiO3 ilmenite contains the highest amount of H,owing to its unique lattice structure with sub-nanometer *** the first time,in situ heating experiments using a transmission electron microscope reveal the concurrent formation of Fe crystals and H2O *** irradiation promotes the endogenous redox reaction,which is helpful for understanding the distribution of OH on the *** findings suggest that the hydrogen retained in LR is a significant resource for obtaining H2O on the Moon,which is helpful for establishing a scientific research station on the Moon.

关键词： establishing endogenous hydrogen

A Localization Method of High Energy Transients for All-sky Gamma-ray Monitor

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Research in Astronomy and Astrophysics 2024年第10期24卷 25-35页

作者： Yi Zhao Wangchen Xue Shaolin Xiong Qi Luo Yuanhao Wang Jiacong Liu Heng Yu xiaoyun Zhao Yue huang Jinyuan Liao Jianchao Sun xiaobo Li Qibin Yi Ce Cai Shuo xiao Shenglun Xie Chao Zheng Yanqiu zhang Chenwei Wang Wenjun Tan Zhiwei Guo Chaoyang Li Zhenghua An Gang Chen Yanqi Du Min Gao Ke Gong Dongya Guo Jiang He Jianjian He Bing Li Gang Li Xinqiao Li Jing Liang xiaohua Liang Yaqing Liu Xiang Ma Rui Qiao Liming song Xinying song Xilei Sun Jin Wang Ping Wang Xiangyang Wen Hong Wu Yanbing Xu Sheng Yang Dali zhang Fan zhang Hongmei zhang Peng zhang Shu zhang Zhen zhang Shijie Zheng Keke zhang Xingbo Han Haiyan Wu Hu Tai Hao Geng Gaopeng Lu Wei Xu Fanchao Lyu Hongbo zhang Fangjun Lu Shuangnan zhang Department of Astronomy Beijing Normal UniversityBeijing 100875China Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China university of Chinese Academy of Sciences Beijing 100049China school of Physics and Optoelectronics Xiangtan UniversityXiangtan 411105China College of Physics Hebei Normal UniversityShijiazhuang 050024China Guizhou Provincial Key Laboratory of Radio Astronomy and Data Processing Guizhou Normal UniversityGuiyang 550001China school of Physics and Electronic Science Guizhou Normal UniversityGuiyang 550001China Institute of Astrophysics Central China Normal UniversityWuhan 430079China College of physics Sciences Technology Hebei UniversityBaoding 071002China Physics and Space Science College China West Normal UniversityNanchong 637002China school of Computing and Artificial Intelligence Southwest Jiaotong UniversityChengdu 611756China College of Electronic and information engineering Tongji UniversityShanghai 201804China Innovation Academy for Microsatellites of Chinese Academy of Sciences Shanghai 201304China National Space Science Center Chinese Academy of SciencesBeijing 100190China school of Earth and Space Sciences University of Science and Technology of ChinaHefei 230026China Electronic Information school Wuhan UniversityWuhan 430072China Key Laboratory of Transportation Meteorology of china Meteorological Administration Nanjing Joint Institute for Atmospheric SciencesNanjing 210000China Key Laboratory of Middle Atmosphere and Global Environment Observation Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China

Fast and reliable localization of high-energy transients is crucial for characterizing the burst properties and guiding the follow-up *** based on the relative counts of different detectors has been widely used for all-sky gamma-ray *** are two major methods for this count distribution localization:χ^(2)minimization method and the Bayesian *** we propose a modified Bayesian method that could take advantage of both the accuracy of the Bayesian method and the simplicity of the χ^(2)*** comprehensive simulations,we find that our Bayesian method with Poisson likelihood is generally more applicable for various bursts than the χ^(2)method,especially for weak *** further proposed a location-spectrum iteration approach based on the Bayesian inference,which could alleviate the problems caused by the spectral difference between the burst and location *** method is very suitable for scenarios with limited computation resources or timesensitive applications,such as in-flight localization software,and low-latency localization for rapidly follow-up observations.

关键词： methods:data analysis methods:analytical (stars:)gamma-ray burst:general