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Trajectory optimisation in electrical discharge machining of three-dimensional curved and twisted channels

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Chinese Journal of Aeronautics 2022年第4期35卷 473-484页

作者： jianshe ZHAO Yicong qiu jian YUAN Chao LIU College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China Laboratory of Integrated Electrical Processing Nanjing HANGPU Machinery Technology Company LimitedNanjing 210000China Military Representative Bureau of the Air Force Equipment Department in Shanghai and Military Representative Office in zhuzhou Region Zhuzhou 412002China AECC South Industry Company Limited Zhuzhou 412002China

Numerical control electrical discharge machining(NC EDM) is one of the most widely used machining technologies for manufacturing a closed blisk flow path, particularly for three-dimensional(3D) curved and twisted flow channels. In this process, tool electrode design and machining trajectory planning are the key factors affecting machining accessibility and efficiency. Herein, to reduce the difficulty in designing the electrode and its motion path in the closed curved and twisted channels, a heuristic search hybrid optimisation strategy based on channel grids is adopted to realise the initial electrode trajectory design search and optimised size reduction. By transferring the trajectory optimisation constraints from the complex free-form surface to numbered grids, the search is found to be more orderly and accurate. The two trajectory indicators, namely argument angle and minimum distance, are analysed separately for the optimised results of the adaptive learning particle swarm optimisation algorithm, demonstrating that they can meet the actual processing *** results of NC EDM indicate that the motion path generated by this design method can meet the machining requirements of 3D curved and twisted flow channels.

关键词： Blisk Electrical discharge machining(EDM) Electrode Objective functions Trajectory generation

Suppression of Rayleigh-Taylor instability by gyroviscosity and sheared axial flow in imploding plasma pinches

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核聚变与等离子体物理 2007年第2期27卷 87-94页

作者： HUANG Lin jian Guang-de qiu Xiao-ming Southwestern In stitute of Physics Chengdu 610041

The synergistic stabilizing effect of gyroviscosity and sheared axial flow on the Rayleigh-Taylor instability in Z-pinch implosions is studied by means of the incompressible viscid magneto-hydrodynamic *** gyroviscosity(or finite Larmor radius) effects are introduced in the momentum equation through an anisotropic ion stress *** relation with the effect of a density discontinuity is *** results indicate that the short-wavelength modes of the Rayleigh-Taylor instability are easily stabilized by the gyroviscosity *** long wavelength modes are stabilized by the sufficient sheared axial ***,the synergistic effects of the finite Larmor radius and sheared axial flow can heavily mitigate the Rayleigh-Taylor *** synergistic effect can compress the Rayleigh-Taylor instability to a narrow wave number *** with a sufficient gyroviscosity and large enough flow velocity,the synergistic effect can completely suppressed the Rayleigh-Taylor instability in whole wave number region.

关键词：雷利-泰勒不稳定性回转粘性内向爆炸等离子体箍缩增敏作用有限拉莫尔旋进半径增长比率

Down-regulation and Clinical Implication of Galectin-9 Levels in Patients with Acute Coronary Syndrome and Chronic Kidney Disease

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Current Medical Science 2020年第4期40卷 662-670页

作者： jian-hua XIE Rui-rui zhu Li ZHAO Yu-cheng ZHONG qiu-tang ZENG Department of Cardiology Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430022China Department of Gastroenterology Hubei Provincial Hospital of Integrated Traditional Chinese and Western MedicineWuhan 430022China

Summary:In various autoimmune diseases,Galecin-9(Gal-9)has been shown to regulate the T-cell balance by decreasing Th1 and Th17,while increasing the number of regulatory T cells(Tregs).However,the role of Gal-9 in the patients with acute coronary syndrome(ACS)and chronic kidney disease(CKD)remains *** study aims to measure the Gal-9 levels in serum and peripheral blood mononuclear cells(PBMCs)in patients with ACS plus CKD and examine their clinical *** serum levels of Gal-9 were determined by enzyme linked immunosorbent assay(ELISA),the expression levels of Gal-9,Tim-3,and Foxp3 mRNA in PBMCs were detected by real-time reverse transcription-polymerase chain reaction(RT-PCR),and the expression of Gal-9 on the surface of PBMCs and in PBMCs was analyzed by flow ***,the correlation of serum Gal-9 levels with anthropometric and biochemical variables in patients with ACS plus CKD was *** lowest levels of Gal-9 in serum and PBMCs were found in the only ACS group,followed by the ACS+CKD group,and the normal coronary artery(NCA)group,.*** Gal-9 levels were increased along with the progression of glomerular filtration rate(GFR)categories of G1 to ***,serum Gal-9 levels were negatively correlated with high-sensitivity C-reactive protein(hs-CRP),estimated GFR(eGFR),and lipoprotein(a),but positively with creatinine,age,osmotic pressure,and blood urea nitrogen(BUN).Notably,serum Gal-9 was independently associated with hs-CRP,osmotic pressure,and lipoprotein(a).Furthermore,serum Gal-9 levels were elevated in patients with type 2 diabetes(T2DM)and impaired glucose tolerance(IGT)in ACS *** was suggested that the levels of Gal-9 in serum and PBMCs were decreased in patients with simple ACS and those with ACS plus CKD,and hs-CRP,eGFR,osmotic pressure and T2DM may have an influence on serum Gal-9 levels.

关键词： Galectin-9 inflammation acute coronary syndrome chronic kidney disease

Uplift and exhumation in the Tianshan,western China:New insights from detrital zircon morphology and thermochronology

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Science China Earth Sciences 2022年第3期65卷 449-461页

作者： jian CHANG Yinglin ZHANG Nansheng qiu Chenxing LI State Key Laboratory of Petroleum Resources and Prospecting China University of PetroleumBeijing 102249China College of Geosciences China University of PetroleumBeijing 102249China

The Tianshan in western China is rich in ore resources,but its tectonic uplift and exhumation history closely related to the resource exploration is still *** study provides a new strategy to uncover the tectonic uplift processes in southern Tianshan by combining the morphological characteristics and thermochronological ages of detrital zircons in the Tarim *** morphology of the Meso-Cenozoic detrital zircons in the Kuqa Foreland Basin,a secondary tectonic unit of the Tarim Basin,is dominated by three types of P,S,and G,and their average alkaline and temperature indexes are 668.0-677.2 and 347.6-413.5,***,the U-Pb ages of these detrital zircons are primarily divided into two groups of 270-330 and 380-470 *** features indicate that the Early Carboniferous-Early Permian and Middle Ordovician-Middle Devonian alkaline granites distributed in the South Tianshan and southern Central Tianshan were the main sources of the detrital zircons in the Kuqa Foreland *** decomposition of the detrital zircon fission track ages further reveals that the provenances of the Kuqa Foreland Basin primarily consisted of the southern Central Tianshan,the eastern South Tianshan,and the central South Tianshan during *** them,the eastern South Tianshan played a dominant role in the material *** synthesis of the decomposed zircon fission track(ZFT)ages and the lag-time evolution pattern indicated that the South Tianshan and the southern Central Tianshan mainly experienced five stages of tectonic uplifting that occurred in the Devonian,the Permian,the Middle Triassic-Middle Jurassic,the Cretaceous,and since the Miocene,*** were related to the subduction of the South Tianshan Ocean northward to the bottom of the Central Tianshan,the compression and accretion after the closure of the South Tianshan Ocean,and a series of collisions between the Qiangtang-Lassa-India plates and the southern margin of the Eurasia pla

关键词： Tianshan Kuqa Foreland Basin Provenance analysis Zircon morphology Thermochronology Lag-time evolution

Linking soil organic carbon mineralization to soil physicochemical properties and bacterial alpha diversity at different depths following land use changes

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Ecological Processes 2023年第1期12卷 545-559页

作者： Jing Guo Wulai Xiong jian qiu Guibin Wang Co-Innovation Center for Sustainable Forestry in Southern China College of ForestryNanjing Forestry University159 Longpan RoadNanjing 210037China

Background Anthropogenic land use changes(LUCs)impart intensifying impacts on soil organic carbon(SOC)turnover,leading to uncertainty concerning SOC mineralization patterns and determining whether soils act as“source”or“sink”in the global carbon ***,understanding the SOC mineralization characteristics of different LUC patterns and their potential influencing factors is *** indoor incubation experiment was conducted to study the SOC mineralization patterns and their relevance to soil physicochemical properties,soil enzyme activity,SOC fractions,and bacterial alpha *** soils were collected from two layers of five typical LUC patterns in Yellow Sea Forest Park,including four that were converted from wheat-corn rotation systems[a gingko plantation(G),a metasequoia plantation(M),a gingko-wheat-corn agroforestry system(GW),and a gingko-metasequoia system(GM)]and a traditional wheat-corn system(W).Results LUCs had significant and diverse impacts on the SOC content and SOC fraction contents and on soil enzyme *** cumulative SOC mineralization was significantly higher in the M systen than in the W and GW systems at 0-20 cm depth and higher in the G system than in the GW system at 20-40 cm depth after 60-day *** mineralization ratio was highest in the W system and lowest in the GW *** soil pH and bulk density had a significant negative correlation with the cumulative SOC mineralization,while the soil bacterial Shannon index had a significant positive correlation with cumulative SOC *** stepwise linear regression analysis showed that the SOC mineralization potential was dominantly explained by the bacterial Shannon index and operational taxonomic units(OTUs).The GW system had lower potentially mineralizable SOC and higher SOC ***,the incubation time and cumulative SOC mineralization were well fitted by the first-order kinetic *** LUCs significantly changed SOC miner

关键词： Land use change Indoor incubation Soil organic carbon mineralization Soil enzyme activity Bacterial alpha diversity

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Insight into the change in carbon structure and thermodynamics during anthracite transformation into graphite

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International Journal of Minerals,Metallurgy and Materials 2020年第2期27卷 162-172页

作者： Tian qiu jian-guo Yang Xue-jie Bai National Engineering Research Center of Coal Preparation and Purification China University of Mining and TechnologyXuzhou 221116China School of Chemical Engineering and Technology China University of Mining and TechnologyXuzhou 221116China

The thermodynamic and kinetic mechanisms of Taixi anthracite during its graphitization process were *** understand the variation trends of carbon arrangement order,microcrystal size,and graphitization degree against temperature during the graphitization process,a series of experiments were performed using Raman spectroscopy and X-ray diffraction(XRD).Subsequently,the influencing factors of the dominant reaction at different temperatures were analyzed using thermodynamics and *** results showed that the graphitization process of Taixi anthracite can be divided into three stages from the perspective of reaction thermodynamics and *** played a crucial role in the formation and growth of a graphitic ***,multivariate mechanisms coexisted in the graphitization *** ultrahigh temperatures,the defects of synthetic graphite could not be completely eliminated and perfect graphite crystals could not be *** low temperatures,the reaction is mainly controlled by dynamics,while at high temperatures,thermodynamics dominates the direction of the reaction.

关键词： anthracite graphitization thermodynamics kinetics

Effect of friction heat on tribological behavior of M2 steel against GCr15 steel in dry sliding systems

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Journal of University of Science and Technology Beijing 2007年第6期14卷 512-516页

作者： Ming qiu Yongzhen Zhang Jun zhu School of Mechatronic Engineering Henan University of Science and Technology Luoyang 471003 China Theory of Lubrication and Bearing Institute Xi＇an Jiaotong University Xi＇an 710049 China School of Material Science and Engineering Henan University of Science and Technology Luoyang 471003 China

The tribological behavior depends significantly on friction heat under high sliding velocity. Many factors influence the conduction rate of friction heat, such as thermophysical properties of the pairs, the formation components of interface-film, environment mediums, etc. Through theoretical and experimental studies on surface temperature, the heat partition approaches have been applied to the pairs of M2 steel against GCr 15 steel to compare and discuss their tribological behavior in dry sliding contact. The results indicate that the values of the contact pressure have little effect on the heat partition at a high sliding velocity of 40 m/s. Furthermore, the degree of correlation between the dynamic temperature and friction coefficient is obvious, and the correlation degree of parameters increases as the pressure grows. A close correlation exists among the temperatures measured from different points of the pin specimen. At last, X-ray diffraction analysis denotes that the carbides of secondary M6C are separated out during the process of friction.

关键词： heat partition contact temperature dry friction dynamic temperature

Synthesis and adsorption performance of lead ion-imprinted micro-beads with combination of two functional monomers

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Journal of Environmental Sciences 2011年第12期23卷 1955-1961页

作者： Linyan zhu Zhiliang zhu Ronghua Zhang Jun Hong Yanling qiu State Key Laboratory of Pollution Control and Resource Reuse Tongji University Shanghai 200092 China Department of Chemistry Tongji University Shanghai 200092 China Key Laboratory of Yangtze River Water Environment Ministry of Education of China Shanghai 200092 China

A novel ion-imprinted polymer, lead ion-imprinted micro-beads with combination of two functional monomers, was synthesized using the W/O/W polymerization method. Two functional monomers, 1,12-dodecanediol-O,O’-diphenyl-phosphonic acid （DDDPA） and 4-vinylpyridine, were used to form a suitable construction with micro-pores fitting the template and recognition sites. The eflects of adsorbent dosage, solution pH and the competitive ions on the adsorption and separation eflciency of lead ions were investigated. The lead ion-imprinted micro-beads were eflcient for lead ions removal from aqueous solution in a broad pH range （4–9）, when the adsorbent dosage was above 0.1 g/L. The adsorption process obeyed the pseudo second-order kinetics model and it only took half an hour to reach the equilibrium. The adsorption isotherm of lead ion was described by the Langmuir model （R2 0.99） with a maximum adsorption capacity of 116.9 mg/g. In the presence of competitive ions Co2＋ and Cd2＋, the lead ion-imprinted micro-beads showed a high selectivity for lead ions. The selectivity coeficient of Pb2＋/Cd2＋ and Pb2＋/Co2＋are 99.3 and 114.7, respectively.

关键词： lead ions adsorption lead ion-imprinted micro-beads selective separation recognition

Microstructure and properties of mullite-based porous ceramics produced from coal fly ash with added Al_2O_3

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International Journal of Minerals,Metallurgy and Materials 2017年第3期24卷 309-315页

作者： jian-bin zhu Hong Yan Department of Materials Processing Engineering School of Mechanical Electrical EngineeringNanchang University School of Mechanical Electrical Engineering Nanchang Institute of Technology

Using coal fly ash slurry samples supplemented with different amounts of Al2O3, we fabricated mullite-based porous ceramics via a dipping-polymer-replica approach, which is a popular method suitable for industrial application. The microstructure, phase composition, and compressive strength of the sintered samples were investigated. Mullite was identified in all of the prepared materials by X-ray diffraction analysis. The microstructure and compressive strength were strongly influenced by the content of Al2O3. As the Al/Si mole ratio in the starting materials was increased from 0.84 to 2.40, the amount of amorphous phases in the sintered microstructure decreased and the compressive strength of the sintered samples increased. A further increase in the Al2O3content resulted in a decrease in the compressive strength of the sintered samples. The mullite-based porous ceramic with an Al/Si molar ratio of 2.40 exhibited the highest compressive strength and the greatest shrinkage among the investigated samples prepared using coal fly ash as the main starting material. © 2017, University of Science and Technology Beijing and Springer-Verlag Berlin Heidelberg.

关键词： Aluminum Amorphous materials Ceramic materials Coal Coal ash Fly ash Microstructure Mullite Porous materials Silicate minerals Sintering Strength of materials X ray diffraction analysis