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Journal of Thermal Science 2020年第4期29卷 955-971页

作者： fu Jinglun CAO Ying ZHANG Chao ZHU Junqiang Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control Tianjin 300384China

Film cooling combined with internal impingement cooling is one of the most effective technologies to protect the gas turbine vanes and blades from the hot gas. In this study, conjugate heat transfer CFD study was undertaken for a flat plate with combined film cooling and impingement cooling. An experiment on conjugate heat transfer of a flat plate with combined film and impingement cooling was performed to validate the code. Then the effects of several parameters including Biot number, blowing ratio, film hole shape and impingement hole diameter on the overall cooling effectiveness were numerically studied. The results show that for a specific combined cooling scheme and a given blowing ratio, the coolant potential can be reasonably allocated to the internal and the external cooling to achieve the overall cooling effectiveness. As the blowing ratio increases, the overall cooling effectiveness trends to reach a maximum value. For different film hole geometrical, the maximum values of the overall cooling effectiveness at high blowing ratio approximate to the same value. At a given mass flow rate of coolant, the increase of the impingement hole diameter leads to the reduction of the overall cooling effectiveness.

关键词： conjugate heat transfer combined film and impingement cooling overall cooling effectiveness Biot number blowing ratio

Drag increment induced by a small-scale forward-facing step in Mach number5 turbulent boundary layer flows

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Chinese Journal of Aeronautics 2020年第10期33卷 2491-2498页

作者： Yifei XUE Jie REN Jinling LUO Song fu School of Aerospace Engineering Tsinghua UniversityBeijing 100084China Department of Mechanical Engineering University of NottinghamNottingham NG72RDUnited Kingdom Beijing Aerospace Technology Institute Beijing 100074China

Small-scale roughness elements or imperfections are inevitable over the surface of a flight *** aerodynamics of these small-scale structures is difficult to predict but may play an important role in the design of a flight vehicle at high *** forward-facing step is a typical type of roughness *** experiments have been conducted to study the aerodynamics of supersonic forward-facing step,especially with a step height larger than boundary layer ***,few studies focus on small *** improve the understanding of small-scale forwardfacing step flow,we perform a series of simulations to analyze its aerodynamic influence on a Mach number 5 turbulent boundary *** general flow structures are analyzed and *** shock waves can be induced by the step even if the step height is much smaller than the boundary layer *** significant shocks are the separation shock and the reattachment *** influenced area by the step is *** the increase of the step height,the non-dimensional influence area decreases and gradually converges when the step height reaches the boundary layer *** are two normalized distributions of the skin friction coefficient and pressure coefficient associated with step *** using the normalized parameters,a power-law relationship between the step height and the drag increment coefficient is revealed and fits the simulation results *** is further illustrated that this relationship still holds when changing the inlet angle of attack,but needs slight modification with the angle of attack.

关键词： Aerodynamics Drag increment Forward-facing step Hypersonic flow Turbulent boundary layer

Study on Soil Denitrification in Wheat-Maize Rotation System

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Agricultural Sciences in China 2006年第1期5卷 45-49页

作者： ZOU Guo-yuan ZHANG fu-suo JU Xiao-tang CHEN Xin-ping liu Xue-jun Institute of Plant Nutrition and Natural Resources Beijing Academy of Agricultural and Forestry Sciences Beijing 100089 P.R.China Department of Plant Nutrition China Agricultural University Beijing 100094 P.R.China

Soil denitrification was studied in wheat-maize rotation cropping system on an aquic cambisol. Results showed that the N loss amount by denitrification ranged from 4.7 to 9.7 kg per hectare with different levels of nitrogen application and the key stage for denitification was during summer maize-growth-period, especially within 1-2 weeks after fertilizer nitrogen was applied. Similar trend was found between soil N2O production/emission dynamic and denitrification dynamic in the rotation system, which may indicate that mainly N2O is produced in nitrification process.

关键词： aquic cambisol winter wheat summer maize denitrification N2O

LOW FLYING HEIGHT MEASUREMENT WITH MULTI-WAVELENGTH INTERFEROMETRY

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Chinese Journal of Mechanical Engineering 2008年第3期21卷 108-111页

作者： WANG Wei lai Wuxing SHI Tielin TAO Wei CHENG Xinjian School of Mechanical Science and Engineering Huazhong University of Science and Technology Wuhan 430074. China Tnbology ＆ Mechanical Characterization Division SAE Magnetics （H.K.） Ltd. Dongguan 523087 China

A method for measurement of ultra-low flying height in head-disk spacing is described. Three different wavelengths are selected out from white light by filters to measure the spacing simultaneously. Besides solving the ambiguity problem, a more reliable result is achieved by using weighted average of measurement results from three different wavelengths, where the weight is dependent upon spacing. Fringe-bunching correction algorithm （FBC） and spot-tilling technique are adopted to suppress calibration and random errors. Moreover, incident bandwidth correction （IBC） method is introduced to compensate the error caused by low monochromaticity of incident light. Based on dynamic flying height tester （DFHT Ⅱ）, with the redesigned of photo-electric conversion and signal acquirement module, an instrument has been developed. And comparing the experimental data from the instrument with those from a KLA-FHT D6, the discrepancy is less than 5%. It indicates that the instrument is suitable to perform ultra-low flying height measurement and satisfies the reauirement of magnetic heads manufacturing.

关键词： Flying height measurement Multi-wavelength interferometry Incident bandwidth

Energy absorption behaviors of a novel buffer lander-leg with Yoshimura core

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Chinese Journal of Aeronautics 2024年第4期37卷 333-342页

作者： Yan XU He HUANG Chao ZHANG Rongji fu School of Aeronautics and Astronautics Zhejiang UniversityHangzhou 310027China School of Mechanics Civil Engineering and Architecture Northwestern Polytechnical UniversityXi’an 710072China

In the current soft-landing system,the lander-leg and the buffer are two independent parts which may cause weight *** traditional mechanical buffers also have their own shortcomings such as small buffer stroke and being non-reusable.A Novel Buffer Lander-leg with Yoshimura core (NBLY) is proposed in this paper,inspired by the Buckling Restrained Brace(BRB).The design details of NBLY and parameter definitions of the core are *** finite element analysis modes have been employed to analyze the nonlinear mechanical behaviors of NBLY subjected to the cyclic *** with four different core styles of hexagon,octagon,dodecagon and hexadecagon are analyzed and *** restraining ratio and cumulative dissipation energy ratio have been obtained to evaluate the energy absorption *** results show that the origami pattern has significant influences on the deformation ductility,plastic energy absorbing and axial load transferring to the *** NBLY with octagon core has outstanding properties,especially the hysteretic energy dissipation and enhancement of compression *** interaction mechanism between the core and encasing member constrains the deformation extensions and contributes to the frictional energy dissipation of the *** paper provides a new conceptual design of buffer lander-leg for soft-landing *** can realize the reuse function as a buffer lander-leg with better loading-bearing and energy absorption behaviors.

关键词： Lander-leg structure Origami Energy absorption Cyclic loading Finite element analysis

Digital Twin for Integration of Design-Manufacturing-Maintenance:An Overview

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Chinese Journal of Mechanical Engineering 2022年第4期35卷 1-20页

作者： Yang fu Gang Zhu Mingliang Zhu fuzhen Xuan Key Laboratory of Pressure Systems and Safety Ministry of EducationSchool of Mechanical and Power EngineeringEast China University of Science and TechnologyShanghai 200237China

Traditional design,manufacturing and maintenance are run and managed independently under their own rules and regulations in an increasingly time-and-cost inefective manner.A unifed platform for efcient and intelligent designmanufacturing-maintenance of mechanical equipment and systems is highly needed in this rapidly digitized *** this work,the defnition of digital twin and its research progress and associated challenges in the design,manufacturing and maintenance of engineering components and equipment were thoroughly *** is indicated that digital twin concept and associated technology provide a feasible solution for the integration of design-manufacturingmaintenance as it has behaved in the entire lifecycle of *** this aim,a framework for information-physical combination,in which a more accurate design,a defect-free manufacturing,a more intelligent maintenance,and a more advanced sensing technology,is prospected.

关键词： Digital twin Design-manufacturing-maintenance integration Artifcial intelligence Deep learning Information fusion Cyber-physical systems

Linear recurring sequences and subfield subcodes of cyclic codes

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Science China Mathematics 2013年第7期56卷 1413-1420页

作者： GAO ZhiHan fu FangWei Department of Combinatorics and Optimization University of Waterloo Chern Institute of Mathematics and LPMC Nankai University

Linear recurring sequences over finite fields play an important role in coding theory and cryptography. It is known that subfield subcodes of linear codes yield some good codes. In this paper, we study linear recurring sequences and subfield subcodes. Let Mqm(f(x)) denote the set of all linear recurring sequences over Fqm with characteristic polynomial f(x) over Fqm . Denote the restriction of Mqm(f(x)) to sequences over Fq and the set after applying trace function to each sequence in Mqm(f(x)) by Mqm(f(x)) | Fq and Tr( Mqm(f(x))), respectively. It is shown that these two sets are both complete sets of linear recurring sequences over Fq with some characteristic polynomials over Fq. In this paper, we firstly determine the characteristic polynomials for these two sets. Then, using these results, we determine the generator polynomials of subfield subcodes and trace codes of cyclic codes over Fqm .

关键词： linear recurring sequences characteristic polynomial cyclic codes subfield subcodes trace codes

Triazole-gold (TAAu) catalyzed three-component coupling (A3 reaction) towards the synthesis of 2,4-disubstituted quinoline derivatives

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Chinese Chemical Letters 2019年第2期30卷 392-394页

作者： fusong Zhang Qi lai Xiaodong Shi Zhiguang Song Department of Chemistry Jilin University Department of Chemistry University of South Florida

A gold-catalyzed three-component coupling reaction (A3 reaction) was developed as an efficient approach for the synthesis of challenging 2, 4-disubstituted quinoline derivatives. Compared to previously reported Cu/Au bi-catalyst system, this protocol enables achieving A3 reaction only in the presence of triazole-gold catalyst. Notably, 4-alkyl substituted or 2-alkyl substituted quinoline derivatives were obtained with good yields, which highlighted the unique advantage of this new strategy.

关键词： Quinoline Gold catalysis A3 reaction Triazole-gold

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咏史怀古类古诗词教学价值分析及对策研究

科教文汇 2025年第1期 164-167页

作者：刘徽刘媛媛衡阳师范学院文学院

咏史怀古类古诗词对学生的知识、审美、情感等方面具有重要价值。针对当前咏史怀古类古诗词存在的一些问题，教师可以从创设情境、优化诵读、群文阅读等角度，探索咏史怀古类古诗词的教学对策。

关键词：咏史怀古类古诗词教学价值教学对策

Multi-dimensional force sensor for haptic interaction:a review

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Virtual Reality & Intelligent Hardware 2019年第2期1卷 121-135页

作者： Aiguo SONG Liyue fu School of Instrument Science and Engineering Southeast UniversityNanjing 210018China

Haptic interaction plays an important role in the virtual reality technology,which let a person not only view the 3D virtual environment but also realistically touch the virtual *** a key part of haptic interaction,force feedback has become an essential function for the haptic ***,multi-dimensional force sensors are widely used in the fields of virtual reality and augmented *** this paper,some conventional multi-dimensional force sensors based on different measurement principles,such as resistive,capacitive,piezoelectric,are briefly *** the mechanical structures of the elastic body of multi-dimensional force sensors are *** is obvious that the performance of the multi-dimensional force sensor is mainly dependent upon the mechanical structure of elastic ***,the calibration process of the force sensor is analyzed,and problems in calibration are *** coupling error is one of the main factors affecting the measurement precision of the multi-dimensional force ***,reducing or even eliminating dimensional coupling error becomes a fundamental requirement in the design of multi-dimensional force sensors,and the decoupling state-of-art of the multi-dimensional force sensors are introduced in this *** last,the trends and current challenges of multi-dimensional force sensing technology are proposed.

关键词： Haptic interaction Virtual reality Multi-dimensional force sensor Elastic body Decoupling Force sensor calibration