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Multi-objective optimization design of airfoil and wing

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Science China(Technological Sciences) 2004年第1期47卷 15-25页

作者： ZHU Ziqiang fu Hongyan yu Rixin liu Jie Beijing University of Aeronautics and Astronautics Beijing 100083China Beijing University of Aeronautics and Astronautics Beijing 100083China Beijing University of Aeronautics and Astronautics Beijing 100083China Beijing University of Aeronautics and Astronautics Beijing 100083China

To extend available monoobjective optimization methods to multiobjective and multidisciplinary optimization, the construction of a suitable resultant objective function (in deterministic method-DM) or a fitness function (in genetic algorithm-GA) is important. An objective function combination method (OFCM) of constructing such a function for constrained optimization problems is suggested. How to use both deterministic and genetic algorithms to biobjetive and bidisciplinary optimal design of high performance airfoils and wings is discussed. Numerical results in both 2D (airfoil) and 3D (wing) cases show that the present method can be used to optimaize different kinds of initial airfoils and wings. The performance of optimized shape is improved significantly. The method is successful and effective.

关键词： multiobjective optimization, genetic algorithm, deterministic optimization method.

Comparison of FGFR1 expression on lens epithelial cells between adults and fetuses

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International Journal of Ophthalmology(English edition) 2011年第1期4卷 37-39页

作者： yu-fu liu, Shu-Ling Peng Beijing Ophthalmology & Visual Sciences Key Lab Tongren Eye Center Beijing Tongren Hospital Capital Medical University Beijing 10005 China Beijing Institute of Ophthalmology Beijing 100730 China

AIM: To study the differences of fibroblast growth factor receptor 1 (FGFR1) gene on human lens epithelial cells (HLECs) of adults and fetuses. METHODS: Indirect in situ RT-PCR was adopted for detection of FGFR1 gene. The cDNA of the nnRNA in the paraffin sections of fetus and adult HLEC was synthesized by reverse transcription reaction. After PCR amplification, in situ hybridization test was performed with synthesized oligonucleotide probe and relative quantification was carried out using image analysis. RESULTS: HLECs of adults and fetuses expressed FGFR1 gene, the expression level was higher in fetuses than in adults. The difference between them had significance (P<0.05). CONCLUSION: FGFR1 Exist in HLEC and the expression is age-related, which could be one of causes of the high occurrence of post operational after-cataract in children.

关键词： human lens epithelial cells fibroblast growth factor receptor 1 indirect in situ RT-PCR after-cataract

A PARTIALLY-AVERAGED NAVIER-STOKES MODEL FOR HILL AND CURVED DUCT FLOW

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Journal of Hydrodynamics 2011年第4期23卷 466-475页

作者： MA Jia-mei WANG fu-jun yu Xin liu Zhu-qing College of Water Conservancy and Civil Engineering China Agricultural University Beijing 100083 China

Turbulent flows past hill and curved ducts exist in many engineering applications. Simulations of the turbulent flow arc carried out based on a newly developed technique, the Partially-Averaged Navier-Stokes （PANS） model, including separation, recirculation, reattachment, turbulent vortex mechanism. The focus is on how to accurately predict typical separating, reattaching and secondary motion at a reasonable computational expense. The effect of the parameter, the unresolved-to-total ratio of kinetic energy （ fk ）, is examined with a given unresolved-to-total ratio of dissipation （ fE ） for the hill flow with a much coarser grid system than required by the LES. An optimal value of fk can be obtained to predict the separation and reattachment locations and for more accurate simulation of the resolved turbulence. In addition, the turbulent secondary motions are captured by a smaller fi as compared with the RANS method with the same grid.

关键词： Partially-Averaged Navier-Stokes (PANS) flow separation recirculation reattachment resolved turbulence

Stereoselective　Syntheses　of　Some　β-D-1-Thioglycopyranosides　and　Bis(β-D-glycopyranosyl)　Sulfides　by　Phase　Transition　Catalysis

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Chemical Research in Chinese Universities 1997年第1期13卷 23-28页

作者： yu Jian xin, liu Fang min, SUN Wan fu and liu yu ting (Department of Chemistry, Xinjiang University, Ulumuqi, 830046) XINJIANG UNIV DEPT CHEMULUMUQI 830046PEOPLES R CHINA

The present paper covers the stereoselective syntheses of four 1 thiogalactopyranosides 1—4 and three thio disaccharides 5—7 through the PTC methods and their structures confirmed by means of elementary analysis, ... 详细信息

关键词： Synthesis Phase transition catalysis Thiogalactopyranoside Thio disaccharide Stereospecificity

A Strong,Tough,and Self-Healing Strengthening Thioctic Acid-based Elastomer for Highly Reliable Flexible Strain Sensor

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Chinese Journal of Polymer Science 2024年第10期42卷 1610-1618,I0016页

作者： Xin-yu Chen yu-Bing fu Xue-Ling Yan Lan liu School of Materials Science and Engineering Key Lab of Guangdong Province for High Property and Functional Polymer MaterialsSouth China University of TechnologyGuangzhou510641China

Elastomers with high strength and toughness,excellent self-healing properties,and biocompatibility have broad application prospects in wearable electronics and other fields,but preparing it remains a *** this work,we propose a highly adaptable strategy by introducing the small molecule crosslinking agent of triethanolamine(TEA)to the poly(thioctic acid)(PTA)chains and preparing the PAx Ey elastomers using a simple synthesis *** strategy stabilizes the PTA chains by constructing multiple non-covalent cross-linked dynamic networks,endowing materials with excellent strength and toughness(tensile strength of 288 kPa,toughness of 278.2 kJ/m3),admirable self-healing properties(self-healing efficiency of 121.6%within 7 h at 70℃),and good *** PAx Ey elastomers can also be combined with MWNTs to become flexible strain sensors,which can be used to monitor human joint movements with high sensitivity,repeatable responses,and stability.

关键词： Thioctic acid Ion clusters Multiple dynamic networks Self-healing strengthening Flexible strain sensor

A typhoon-induced storm surge numerical model with GPU acceleration based on an unstructured spherical centroidal Voronoi tessellation grid

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Acta Oceanologica Sinica 2024年第3期43卷 40-47页

作者： yuanyong Gao fujiang yu Cifu fu Jianxi Dong Qiuxing liu National Marine Environmental Forecasting Center Beijing 100081China Key Laboratory of Marine Hazards Forecasting Ministry of Natural ResourcesBeijing 100081China

Storm surge is often the marine disaster that poses the greatest threat to life and property in coastal *** and timely issuance of storm surge warnings to take appropriate countermeasures is an important means to reduce storm surge-related *** surge numerical models are important for storm surge *** further improve the performance of the storm surge forecast models,we developed a numerical storm surge forecast model based on an unstructured spherical centroidal Voronoi tessellation(SCVT)*** model is based on shallow water equations in vector-invariant form,and is discretized by Arakawa C *** SCVT grid can not only better describe the coastline information but also avoid rigid transitions,and it has a better global consistency by generating high-resolution grids in the key areas through transition *** addition,the simulation speed of the model is accelerated by using the openACC-based GPU acceleration technology to meet the timeliness requirements of operational ensemble *** only takes 37 s to simulate a day in the coastal waters of *** newly developed storm surge model was applied to simulate typhoon-induced storm surges in the coastal waters of *** hindcast experiments on the selected representative typhoon-induced storm surge processes indicate that the model can reasonably simulate the distribution characteristics of storm *** simulated maximum storm surges and their occurrence times are consistent with the observed data at the representative tide gauge stations,and the mean absolute errors are 3.5 cm and 0.6 h respectively,showing high accuracy and application prospects.

关键词： typhoon-induced storm surge numerical model GPU acceleration unstructured grid spherical centroidal Voronoi tessellation(SCVT)

Housing vacancy identification in shrinking cities based on multi-source data:A case study of fushun city in Northeast China

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Journal of Geographical Sciences 2024年第1期34卷 89-111页

作者： SUN Hongri ZHOU Guolei liu Yanjun fu Hui JIN yu School of Geographical Sciences Northeast Normal UniversityChangchun 130024China Northeast Institute of Geography and Agroecology CASChangchun 130102China

Urban shrinkage has attracted the attention of many geographers and urban planners in recent ***,there are fewer studies on vacant housing in shrinking ***,this study combines multi-source remote sensing images and urban building data to assess the spatiotemporal variation patterns of housing vacancy in a typical shrinking city in *** following points were obtained:(1)We developed an evaluation model to identify vacant residential buildings in shrinking cities by removing the contribution of nighttime lights from roads and non-residential buildings;(2)The residential building vacancy rate in fushun city significantly increased from 2013 to 2020,resulting in a significant high-value clustering *** impact of urban shrinkage on vacant residential buildings was higher than that on vacant non-residential buildings;(3)The World Pop population data demonstrated consistent spatial distribution and trend of population change in fushun with the residential building vacancy rate results,suggesting good reliability of the constructed evaluation model in this *** housing vacancies can help the local government to raise awareness of the housing vacancy problem in shrinking cities and to propose reasonable renewal strategies.

关键词： housing vacancy residential building vacancy urban shrinkage VIIRS

Controlling of coordination state of Ru_(x)N_(y) clusters for efficient oxygen reduction electrocatalysis

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Nano Research 2024年第3期17卷 1035-1041页

作者： Weiyang fu Yihuan yu Tongtong liu Yinliang Cao Zhengping Zhang Feng Wang State Key Laboratory of Chemical Resource Engineering Beijing Key Laboratory of Electrochemical Process and Technology for MaterialsBeijing University of Chemical TechnologyBeijing 100029China Beijing Advanced Innovation Center for Soft Matter Science and Engineering Beijing University of Chemical TechnologyBeijing 100029China Zhejiang Tianneng Hydrogen Energy Technology Co. Ltd.Huzhou 313100China

Ruthenium(Ru)is an attractive potential alternative to platinum as an electrocatalyst for the oxygen reduction reaction(ORR),in virtue of its high catalytic selectivity and relatively low *** this work,a series of well-dispersed nitrogen-coordinated Ru-clusters on carbon black(Ru_(x)N_(y)/C)were prepared by pyrolyzing different Ru-containing sandwich compounds as the Ru *** higher thermal stability of these complexed sandwich precursors(bis(1,2,3,4,5-pentamethylcyclopentadienyl)Ru(II)monomer,dichloro(p-cymene)Ru(II)dimer,and chloro(1,2,3,4,5-pentamethylcyclopentadienyl)Ru(II)tetramer)affords the control of coordinated state for the resulting Ru-clusters,in comparison of that derived from ruthenium *** the pyrolysis treatment,the Ru coordinated state in Ru_(x)N_(y)/C,with the Ru–N and Ru–Ru bonds,still showed the structural inheritance from the Ru(II)monomer,dimer,and tetramer,but using ruthenium chlorides as the Ru source resulted in the nanoscale Ru *** ORR testing exhibited that the Ru_(x)N_(y)/C sample derived from the Ru(II)tetramer(Ru_(x)N_(y)/C-T)presents the higher catalytic activity than the other obtained samples in either alkaline or acidic *** in the acidic electrolyte,Ru_(x)N_(y)/C-T shows the comparable ORR activity to that of Pt/C catalysts,and it shows the superior tolerance against methanol and *** X-ray absorption spectroscopy and density functional theory calculations demonstrate that these tetra-nuclear Ru-clusters could be the most active site due to their broadened d-orbital bands and lower energy d-band center than those of other subnano species and nanocrystals,and their favorable Yeager-type adsorption of O_(2)-molecules is also contributed to promoting O–O bond cleavage and accelerating the ORR process.

关键词： ruthenium clusters coordination environment sandwich compounds electrocatalysis oxygen reduction reaction

Improving Thermal-oxidative Aging Resistance of Styrene-butadiene Rubber by Antioxidant Loaded Silica Aerogel

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Chinese Journal of Polymer Science 2024年第8期42卷 1198-1209页

作者： Xue-Fei Ping yu Wang Lu liu fu-Yong liu Hong-Wei He Pi Wang Wen-Wen yu Qiang Zheng College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering Taiyuan 030032China Key Laboratory of Macromolecular Synthesis and functionalization Department of Polymer Science and EngineeringZhejiang UniversityHangzhou 310058China

The antioxidant N-isopropyl-N'-phenyl-p-phenylenediamine(4010NA)was dissolved in ethanol and impregnated into silica aerogel(SAG)via vacuum-pressure cycles,yielding composite particles(A-N)with enhanced sustained-release and reinforcing *** effect of A-N on the mechanical properties and thermal-oxidative aging resistance of styrene-butadiene rubber(SBR)vulcanizates was *** and BET assessments indicated that the loading efficiency of 4010NA in SAG reached 14.26%within ethanol's solu bility *** A-N into SBR vulcanizates significantly elevated tensile strength by 17.5%and elongation at break by 41.9%over those with fumed silica and ***,A-N notably enhanced the thermal-oxidative aging resistance of *** aging for 96 h at 100℃,the tensile strength and elongation at break of SBR with A-N sustained 70.09%and 58.61%of their initial values,respectively,with the retention rate of elongation at break being 62.8%higher than that of SBR with fumed silica and free *** study revealed that A-N composite particles significantly inhibited the crosslinking in SBR's molecular chains,reducing hardening and embrittlement during later thermal-oxidative aging stages.

关键词： Styrene-butadiene rubber Silica aerogel Loading modification Thermal-oxidative aging