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Minimizing airfoil drag at low angles of attack with DBD-based turbulent drag reduction methods

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Chinese Journal of Aeronautics 2023年第4期36卷 104-119页

作者： zhi SU Haohua ZONG Hua LIANG Jun LI Like XIE Xuecheng LIU Weiliang kong Borui ZHENG Science and Technology on Plasma Dynamics Laboratory Air Force Engineering UniversityXi’an 710038China Institute of Aero-engine School of Mechanical EngineeringXi’an Jiaotong UniversityXi’an 710049China The Green Aerotechnics Research Institute of Chongqing Jiaotong University Chongqing 404100China

Dielectric Barrier Discharge(DBD)based turbulent drag reduction methods are used to reduce the total drag on a NACA 0012 airfoil at low angels of *** interaction of DBD with turbulent boundary layer was investigated,based on which the drag reduction experiments were *** results show that unidirectional steady discharge is more effective than oscillating discharge in terms of drag reduction,while steady impinging discharge fails to finish the mission(*** increase).In the best scenario,a maximum relative drag reduction as high as 64%is achieved at the freestream velocity of 5 m/s,and a drag reduction of 13.7%keeps existing at the freestream velocity of 20 m/*** unidirectional discharge,the jet velocity ratio and the dimensionless actuator spacing are the two key parameters affecting the *** drag reduction magnitude varies inversely with the dimensionless spacing,and a threshold value of the dimensionless actuator spac-ing of 540(approximately five times of the low-speed streak spacing)exists,above which the drag *** the jet velocity ratio smaller than 0.05,marginal drag variation is *** con-trast,when the jet velocity ratio larger than 0.05,the experimental data bifurcates,one into the drag increase zone and the other into the drag reduction zone,depending on the value of dimensionless actuator *** both zones,the drag variation magnitude increases with the jet velocity *** total drag reduction can be divided into the reduction in pressure drag and turbulent friction drag,as well as the increase in friction drag brought by transition *** reduction in tur-bulent friction drag plays an important role in the total drag reduction.

关键词： Dielectric barrier discharge Dimensionless scaling Plasma actuator Turbulent friction drag Wake

Fundamental kinematics laws of interstitial fluid flows on vascular walls

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Theoretical & Applied Mechanics Letters 2021年第3期11卷 146-150页

作者： Yajun Yin Hongyi Li gang Peng Xiaobin Yu Yiya kong Department of Engineering Mechanics Tsinghua UniversityBeijing 100084China Beijing Hospital National Center of GerontologyInstitute of Geriatric MedicineChinese Academy of Medical SciencesBeijing 100730China

In the previous studies,the phenomenon that the interstitial fluid(ISF)can flow along tunica adventitia of the arteries and veins in both human and animal bodies was *** the basis of these studies,this paper aims to:(i)summarize the basic properties of the ISF flows in the walls of arteries and veins,(ii)combine the basic properties with axiomaticism and abstract the axiom for ISF flows,and(iii)propose three fundamental laws of the ISF flow,(i.e.,the existence law,the homotropic law and the reverse law).The three laws provide solid theoretical basement for exploring the kinematic patterns of interstitial fluid flow in the cardiovascular system.

关键词： Vascular walls Interstitial fluid flow Essential flowing properties Fundamental kinematics laws

Morphology-Controlled Growth of A1N One-Dimensional Nanostructures

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Journal of Materials Science & Technology 2008年第4期24卷 608-614页

作者： Ting XIE Min YE Xiaosheng FANG zhi JIANG Li CHEN Mingguang kong Yucheng WU Lide ZHANG Institute of Tribology Hefei University .of Technology Hefei 230009 China Key laboratory of Materials Physics Institute of Solid State Physics Chinese Academy of Sciences Hefei 230031 China

Aluminum nitride （AIN） nanowires, serrated nanoribbons, and nanoribbons were selectively obtained through a simple chloride assisted chemical vapor deposition process. The morphologies of the products could be controlled by adjusting the deposition position and the flux of the reactant gas. The morphologies and structures of the AIN products were investigated in detail. The formation mechanism of the as-prepared different morphologies of AIN one-dimensional （ID） nanostructures was discussed on the basis of the experimental results.

关键词： Aluminum nitride Morphology-controlled growth One-dimensional nanostructure

Mesoscopic measurement of damage and shear bands of granite residual soil using Micro-CT and digital volume correlation

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Journal of Mountain Science 2023年第11期20卷 3423-3436页

作者： LI Cheng-sheng ZHANG Bing-xin LIU zhi-jun kong Ling-wei SHU Rong-jun Department of Civil and Environmental Engineering Shantou UniversityShantou 515000China State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChineseAcademy of SciencesWuhan 430000China College of Civil and Architecture Engineering Chuzhou UniversityChuzhou 239000China

The mesomechanics of geotechnical materials are closely related to the macromechanical properties,especially the mesoscale evolution of shear bands,which is helpful for understanding the failure mechanism of geotechnical ***,there is lack of effective quantitative analysis method for the complex evolution mechanism of threedimensional shear *** this work,we used X-ray computed tomography(CT)to reconstruct volume images and used the digital volume correlation(DVC)method to calculate the three-dimensional strain fields of granite residual soil samples at different loading *** trend of the failure surface of the shear bands was obtained by the planar fitting method,and the connectivity index was constructed according to the projection characteristics of the shear bands on the failure trend *** results support the following findings:the connectivity index of the shear band increases rapidly and then slowly with increasing axial strain,which is characterized by a near'S'*** the stress reaches the peak value,the connectivity index of the shear bands almost exceeds *** contribution of the new shear band volume to the connectivity of the shear bands becomes increasingly small with increasing axial *** by quartz grains and stress at the initial stage,the dip angle gradually and finally approaches the included angle of the maximum shear stress from the discrete state with increasing axial *** tendency and dip angle of the resulting shear bands are dynamic,and the tendency slightly deflects with increasing loading.

关键词： Damage Shear band Digital volume correlation Micro-CT Granite residual soil

Effect of Waxy Wheat Flour Blends on the Quality of Fresh and Stale Bread

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Agricultural Sciences in China 2009年第4期8卷 401-409页

作者： QIN Peng MA Chuan-Xi WU Rong-lin kong zhi-you ZHANG Bo-qiao College of Agronomy and Biotechnology Yunnan Agricultural University Kunming 650201 P.R.China Agricultural Research Institute of Lixiahe Region Yangzhou 225007 P.R. China College of Agronomy Anhui Agricultural University Hefei 230036 P.R. China Department of Biology and Chemistry Baoshan Teachers College Baoshan 678000 P.R.China

Starch is the major component in the wheat kernel, which is mainly composed of amylose and amylopectin. The wheat without amylose in its endosperm was called ＂waxy wheat＂. Waxy wheat can be used to adjust the amylose content and improve the wheat-based food quality by adding to non-waxy wheat flour. In order to investigate the effect of waxy wheat flour on the quality of fresh and stale bread, waxy wheat flour was added into the flour of Canadian Spring Wheat 2 at 0.0, 5.0, 10.0, 15.0, 20.0, 25.0, 30.0, and 35.0% to make breads. The physicochemical properties were adjusted to suitability by adding Yangmai 158 flour, and breads were evaluated for sensory quality, crumb firmness, loaf volume and weight loss over a period of 0, 2, 4, and 6 days. The result showed that the best total score of fresh bread was 82.9 by adding waxy flour at 7.0%, though no significant difference was found among blends with 0.0-15.0% of waxy flour. Breads with the addition of 22.0% waxy flour had lower firmness, and decreasing loss of weight. Waxy wheat flour blend at 15.0% was optimal in retarding staling without significant decreasing fresh bread quality in comparison to the control.

关键词： waxy wheat fresh bread stale bread quality

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铁基氧化物团簇催化CO还原NO反应模拟

原子与分子物理学报 2025年第6期42卷 22-30页

作者：刘众元孔繁宇陈琳梁五洲刘志兵高义斌国网山西省电力公司电力科学研究院太原030001 太原理工大学太原030024

固定床实验表明,在深度欠氧的条件下,铁基氧化物对CO还原NO的反应具有催化作用.为进一步理解脱销催化反应机理,本文利用量化软件Gaussian模拟了铁及其三种不同价态氧化物团簇:Fe_(2)团簇、Fe_(2)O_(2)团簇、Fe_(2)O_(3)团簇催化CO还原N... 详细信息

固定床实验表明,在深度欠氧的条件下,铁基氧化物对CO还原NO的反应具有催化作用.为进一步理解脱销催化反应机理,本文利用量化软件Gaussian模拟了铁及其三种不同价态氧化物团簇:Fe_(2)团簇、Fe_(2)O_(2)团簇、Fe_(2)O_(3)团簇催化CO还原NO的反应路径,为进一步改进脱硝反应提供理论基础.本文分析了反应过程的各阶段能量壁垒,三种团簇中最容易发生催化反应的团簇为Fe_(2),整个反应过程中的决速步为NO在Fe_(2)团簇上的解离吸附过程.

关键词：铁团簇脱硝模拟反应机理

维普期刊数据库博看期刊

Real-Time Slab Quality Diagnosis and Analysis System Based on Solidification Mechanism

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Journal of Iron and Steel Research International 2013年第12期20卷 40-46页

作者： FENG Ke WANG Shui-gen HAN zhi-wei kong Yi-wen CAO Jian-feng CISDI Research and Development Co. Ltd. Continuous Casting Department CISDI Engineering Co.Ltd.

According to the two types of slab defects （surface crack and internal crack）, a real-time slab quality diag nosis and analysis system named CISDI_SQDS ONLINE R2011 was developed based on heat transfer and solidifica tion simulation, stress and strain calculation as well as metallurgical process analysis about continuous casting, com- bined with expert knowledge database for specific casting events. The respective crack formation indexes were intro duced as the theoretical reference data for slab quality level evaluation. Meanwhile, both the quality loss factors relat ed to casting metallurgical rules and the adjusting factors related to casting events were taken into full consideration, which was integrated organically with theoretical analysis and expert system. The system can be widely used as an important theoretical tool for prediction and control of slab quality in slab continuous casting process.

关键词： slab continuous casting internal crack surface crack quality diagnosis

Lethal and Sub-Lethal Effects of Transgenic Rice Containing cry1Ac and CpTI Genes on the Pink Stem Borer, Sesamia inferens(Walker)

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Agricultural Sciences in China 2011年第3期10卷 384-393页

作者： HAN Lan-zhi HOU Mao-lin WU kong-ming PENG Yu-fa WANG Feng State Key Laboratory of Plant Disease and Insect Pests/Institute of Plant Protection Chinese Academy of Agricultural Sciences Beijing 100193P. R. China Key Laboratory of Agricultural Genetics Engineering Fujian Academy of Agricultural Sciences Fuzhou 350003 P.R.China

Lethal and sub-lethal effects of transgenic rice containing cry1Ac and CpTI genes on the pink stem borer, Sesamia inferens, were studied to collect information for ecological risk assessment on insect-resistance of transgenic rice. In vitro insect-feeding bioassays were conducted to evaluate the lethal and sub-lethal effects of transgenic rice lines （II YouKF6 and KF6） containing cry1Ac＋CpTI genes on S. inferens at four different growth stages, viz., seedling, tillering and elongation, booting, and milk and maturing. Transgenic rice at seedling stage showed significantly high lethal effect on S. inferens with the shortest lethal duration for 50 and 100% individuals and the highest corrected mortalities after feeding on transgenic lines at this stage for 3 and 6 d. Followed by tillering and elongation stage, 50 and 100% S. inferens were dead after feeding on transgenic lines at this stage for 4 and 10 d, respectively. Moreover, corrected mortalities for 6 d feeding on transgenic lines at this stage were significantly higher than that at booting, and milk and maturing stages. Lethal effect of KF6 on S. inferens decreased significantly at booting stage. Lethal duration for 50% S. inferens significantly extended and its corrected mortalities for 6 d feeding also declined remarkably. However, lethal effect of II YouKF6 on S. inferens did not decrease significantly at this stage. Transgenic rice at booting, and milk and maturing stages did not show significant lethal effect to S. inferens and it showed the longest lethal duration for 50% individuals and the lowest corrected mortalities for 3 and 6 d feeding. A few larvae of S. inferens could survive, pupate and emerge on these two transgenic lines at booting, and milk and maturing stages. Sub-lethal effect of two transgenic lines on S. inferens also differed significantly between different developmental stages. Continuously feeding on transgenic rice lines at seedling, and tillering and elongation stages delayed the devel

关键词： transgenic rice Sesamia inferens lethal and sub-lethal effect

Observations of Giant Pulses of the Crab Pulsar

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Chinese Journal of Astronomy and Astrophysics 2008年第3期8卷 277-284页

作者： Ling-Jun kong Ali Esamdin Cheng-Shi Zhao zhi-Yong Liu Jian-Ping Yuan Urumqi Observatory NAOC Chinese Academy of Sciences Urumqi 830011 China Graduate University of Chinese Academy of Sciences Beijing 100049 China

The Crab Pulsar was observed at 1540MHz with the 25m radio telescope at Urumqi with a filterbank de-dispersion backend. A total of 2436 giant pulses with pulse energies larger than 4300 Jy μs were detected in two observing sets. All of these giant pulses are located in the main pulse （MP） and inter pulse （IP） windows of the average profile of the Crab Pulsar. The ratio of the numbers of giant pulses detected in the IP and MP windows is about 0.05. Our results show that, at 1540MHz, the emission in the IP is contributed by giant and normal pulses, while that in the MP is almost dominated by giant pulses. The distribution of energy of the 2436 giant pulses at 1540 MHz can be described by a power-law with index α = 3.13 ± 0.09. The intrinsic threshold of giant pulse energy in the MP window is about 1400Jy μs at 1540MHz.

关键词： stars neutron -- pulsars general -- pulsars individual Crab Pulsar