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Experimental study on the meso-scale milling of tungsten carbide WC-17.5Co with PCD end mills

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Advances in Manufacturing 2020年第2期8卷 230-241页

作者： Wei Zhao Asif Iqbal Ding fang ning He Qi Yang College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016People's Republic of China Faculty of Integrated Technologies Universiti Brunei DarussalamJalan Tungku LinkGadong BE1410Brunei Darussalam Chengdu Aircraft Industrial(Group)Co LtdChengdu 610092People's Republic of China

Tungsten carbide is a material that is very difficult to cut,mainly owing to its extreme wear *** high value of yield strength,accompanied by extreme brittleness,renders its machinability extremely poor,with most tools *** when cutting with tool materials of the highest quality,its mode of cutting is mainly brittle and marred by material *** ductile mode of cutting is possible only at micro leveIs of depth of cut and feed *** study aims to investigate the possibility of milling the carbide material at a meso-scale using polycrystaline diamond(PCD)end mills.A series of end milling experiments were performed to study the effects of cutting speed,feed per tooth,and axial depth of cut on performance measures such as cutting forces,surface roughness,and tool *** characterize the wear of PCD tools,a new approach to measuring the level of damage sustained by the faces of the cutter's teeth is *** of the experimental data show that the effects of all the cutting parameters on the three performance measures are *** major damage mode of the PCD end mills *** to be the intermittent *** progress of tool damage saw a long,stable,and steady period sandwiched between two short,abrupt,and intermittent *** forces and surface roughness are found to rise with increments in the three cutting parameters,although the latter shows signs of reduction during the initial increase in cutting speed *** results of this study find that an acceptable surface quality(average roughness Ra600mm)can be obtained under the conditions of the given cutting *** indicates that milling with PCD tools at a meso-scale is a suitable machining method for tungsten carbides.

关键词： Tungsten carbide Meso-scale milling Polycrystalline diamond(PCD)end mill Cutting force Surface roughness Tool wear

Angular velocity estimation using characteristics of star trails obtained by star sensor for spacecraft

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Science China(Information Sciences) 2021年第1期64卷 201-214页

作者： Xiaolin ning Pingping CHEN Yueqing HUANG Weiren WU Jiancheng fang School of Instrumentation Science & Opto-electronics Engineering Beihang University Lunar Exploration and Space Program Center China National Space Administration

Many studies have been conducted about angular velocity estimation using star sensors, and fairly good performance is achieved when the spacecraft is working at low-dynamic environments. However,when the spacecraft rotates at a large angular velocity, the star image will become blurred, which makes it difficult to identify and recognize star centroids, which, in turn, reduces the accuracy of angular velocity estimation. Therefore, to solve the problem with angular velocity estimation in highly dynamic situations,this research studies a method of angular velocity estimation using blurred star images. The length and ending point coordinates of star trails obtained from these blurred star images are used for a series of processes, which includes the pre-processing of blurred star images, determination of starting and ending points, thinning and selection of star trails, and calculation of trail lengths. Simulations show that the effectiveness of the proposed method in highly dynamic situations and the angular velocity estimation errors in constant and sinusoidal variation are reduced by at least 66% and 62%, respectively, compared with those of the traditional method.

关键词： angular velocity estimation star sensor blurred star images star trail characteristics unscented Kalman filter

Antimagicness of Lexicographic Product Graph G[Pn]

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Acta Mathematicae Applicatae Sinica 2020年第3期36卷 603-619页

作者： ying-yu LU Guang-hua DONG ning WANG School of Mathematical Sciences Tiangong UniversityTianjin 300387China Lushan College of Guangxi University of Science and Technology Liuzhou 545000China Department of Information Science and Technology Tianjin University of Finance and EconomicsTianjin 300222China

Hartsfield and Ringel conjectured that every connected graph other than K2 is *** then,many classes of graphs have been proved to be *** few is known about the antimagicness of lexicographic product *** this paper,via the construction of a directed Eulerian circuit,the Siamese method,and some modification on graph labeling,the antimagicness of lexicographic product graph G[Pn]is obtained.

关键词： antimagic labeling lexicographic product

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Survey and Tutorial on Hybrid Human-Artificial Intelligence

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Tsinghua Science and Technology 2023年第3期28卷 486-499页

作者： Feifei Shi fang Zhou Hong Liu Liming Chen Huansheng ning School of Computer and Communication Engineering University of Science and Technology BeijingBeijing 100083China School of Computer Science and Software Engineering East China Normal UniversityShanghai 200062China Faculty of Computing Ulster UniversityNewtownabbey BT370QBUK

The growing computing power,easy acquisition of large-scale data,and constantly improved algorithms have led to a new wave of artificial intelligence(AI)applications,which change the ways we live,manufacture,and do *** with this development,a rising concern is the relationship between AI and human intelligence,namely,whether AI systems may one day overtake,manipulate,or replace *** this paper,we introduce a novel concept named hybrid human-artificial intelligence(H-AI),which fuses human abilities and AI capabilities into a unified *** presents a challenging yet promising research direction that prompts secure and trusted AI innovations while keeping humans in the loop for effective *** scientifically define the concept of H-AI and propose an evolution road map for the development of AI toward *** then examine the key underpinning techniques of H-AI,such as user profile modeling,cognitive computing,and human-in-the-loop machine ***,we discuss H-AI’s potential applications in the area of smart homes,intelligent medicine,smart transportation,and smart ***,we conduct a critical analysis of current challenges and open gaps in H-AI,upon which we elaborate on future research issues and directions.

关键词： hybrid human-artificial intelligence(H-AI) Internet of Things(IoT) artificial intelligence(AI)

Visualization of the protective role of estrogen against female liver fibrosis via an ER viscosity NIR fluorescent probe

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Science China Chemistry 2025年第1期 360-368页

作者： Zheng Liu Changyu Zhang Zipeng Li Wanying Ma Jia Liu Xiang Xia ning Xu Wen Sun Jianjun Du Jiangli Fan Xiaojun Peng State Key Laboratory of Fine Chemicals Dalian University of Technology ningbo Institute of Dalian University of Technology

Endoplasmic reticulum(ER) viscosity has emerged as a new potential biomarker for hepatic fibrosis(HF). Herein, we report the first ER-targeting viscosity-responsive near-infrared(NIR) fluorescent probe HBT-PP for investigations of HF *** twisted intramolecular charge transfer(TICT) and the excited state intramolecular proton transfer(ESIPT) are combined to endow HBT-PP with the selective response towards viscosity(～62-fold) and a super large stokes shift(～320 nm). HBT-PP mainly targets organelle ER and is able to image the drug-or alcohol-induced viscosity elevation in living cells. Significantly,HBT-PP was successfully applied to visualize the gender difference in HF and the protective role of estrogen in restraining HF progression. Of note, after 10 min of stain with HBT-PP, HF lesions showed a stage-based response, indicating the potential of this probe in fast and early diagnosis of HF. These results clearly demonstrated the promising application of HBT-PP as a new tool for exploring ER viscosity-involved physiological and pathological processes.

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A constitutive model based on the evolution and coalescence of elliptical micro-cracks for quasi-brittle materials

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Chinese Science Bulletin 2012年第28期57卷 3773-3781页

作者： ning JianGuo REN HuiLan fang MinJie State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology Beijing 100081 China

Damage and failure of quasi-brittle materials are caused by the evolution and coalescence of *** solve the problem of elliptical micro-crack growth at the elastic deformation stage,a method of complex potential functions is proposed and the effect of the initial orientation on micro-crack growth and deflection is *** critical stress condition for the initial damage is derived according to the criterion of micro-crack *** on energy conservation during wing-crack propagation,a damage constitutive model is developed with the strain criterion created in the condition of micro-crack *** stress-strain curves of quasi-brittle materials in uniaxial compression obtained based on this model are examined with the experimental results.

关键词：损伤本构模型准脆性材料微裂纹椭圆形合并基础演变裂纹生长

Significantly improved oxidation of bio-based furans into furan carboxylic acids using substrate-adapted whole cells

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Journal of Energy Chemistry 2020年第2期29卷 20-26页

作者： Mao Wen Xue-ying Zhang Min-Hua Zong ning Li School of Food Science and Engineering South China University of TechnologyGuangzhou 510640GuangdongChina

Furan carboxylic acids are important building blocks in polymer and fine chemical industries. In this work, a simple substrate adaptation strategy was applied to improve the catalytic performances of Comamonas testosteroni SC1588 cells for the synthesis of various furan carboxylic acids. It was found that biocatalytic synthesis of 5-hydroxymethyl-2-furancarboxylic acid(HMFCA) was substantially promoted by adding histidine and increasing cell concentrations. HMFCA was produced in a quantitative yield from200 m M HMF in 24 h. Besides, the HMFCA yields of 71%–81% were achieved with the substrate concentrations up to 250–300 m M. It was firstly found that 4-tert-butylcatechol(TBC), as the stabilizer present in HMF, exerted a significantly detrimental effect on whole-cell catalytic synthesis of HMFCA at high substrate concentrations(more than 130 m M). In addition, a variety of furan carboxylic acids such as2-furoic acid, 5-methyl-2-furancarboxylic acid and 5-methoxymethyl-2-furancarboxylic acid were synthesized with the yields up to 98%.

关键词： 5-hydroxymethylfurfural 5-hydroxymethyl-2-furancarboxylic acid Oxidation Substrate adaptation strategy Whole-cell biocatalysis

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Three-Dimensional Direct Numerical Simulation of Flow past A Near-Wall Circular Cylinder:Combined Effects of Gap Ratio and Boundary Layer Thickness on Flow Profiles and Pressure Distribution

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China Ocean Engineering 2023年第6期37卷 948-961页

作者： ying Chao HUA Yang WEI Yu-han JI Chun-ning Zhejiang Institute of Hydraulics&Estuary(Zhejiang Institute of Marine Planning and Design) Hangzhou 310020China Shanghai Investigation Design&Research Institute Co.Ltd.Shanghai 200335China State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China

Three-dimensional direct numerical simulations of the wake flow downstream of a near-wall circular cylinder at different gap ratios and boundary layer thicknesses are carried out by using the iterative immersed boundary *** non-dimensional gap between the cylinder and the wall,G/D=0.2,0.6 and 1.0,the non-dimensional boundary layer thickness,δ/D=0.0,0.7 and 1.6,the Reynolds number,Re=350,and the aspect ratio of the cylinder,L/D=25are ***-resolution visualizations of the complex vortex structures at differentδ/D and G/D are *** transition of the streamwise vortex mode,the combined effects ofδ/D and G/D on the flow statistics,the pressure and shear stress distribution and the hydrodynamic forces are *** show that with decreasing G/D and increasingδ/D,the gap flow and its vortex-shedding are significantly weakened,together with an elongated wake and an enlarged low-velocity area near the wall,leading to the wake mode transition from the two-sided to one-sided *** relative positions of the cylinder regarding the boundary layer alter the flow features of the shear *** an increase inδ/D,the front stagnation point shifts to the upper surface,and the distance between the flow divergence point and the maximum pressure position *** mean drag coefficient and *** of drag and lift coefficients decrease with a decrease in G/D and an increase inδ/D,while the mean lift coefficient increases with decreasing G/D but decreases with increasingδ/D.

关键词： cylinder wake near-wall effect direct numerical simulation boundary layer thickness gap ratio

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Palladium installed copper-organic framework for C–C coupling reactions

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Science China Chemistry 2025年

作者： Yu-Mei Wang Mei-Xia Tao Kai-Ming Mo Xu Chen Shu-Hua Zhong Elena S Shubina Guo-Hong ning Dan Li College of Chemistry and Materials Science Guangdong Provincial Key Laboratory of Supramolecular Coordination ChemistryJinan University A.N.Nesmeyanov Institute of Organoelement Compounds Russian Academy of Sciences

The formation of C–C bonds is a crucial aspect of organic synthesis. Synthesists' long-term objective is to identify novel catalysts to optimize reaction systems based on traditional transition metal catalysis. This study explores the synthesis and catalytic potential of palladium-installed covalent metal-organic frameworks(CMOFs) based on copper cyclic trinuclear units(Cu-CTUs). By incorporating palladium ions into the imine-based framework JNM-7 through a straightforward immersion method, we achieved a notable enhancement in catalytic activity for critical C–C coupling reactions, including C–H arylation and Sonogashira cross-coupling. The resulting JNM-7-Pd demonstrated remarkable stability and recyclability, maintaining its efficiency over at least three cycles without any decline in efficiency.

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