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Heat Transfer Characteristics outside the Condenser of a Rotating Heat Pipe Grinding Wheel with a Lateral Air Impinging Jet

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Journal of Thermal Science 2021年第2期30卷 493-503页

作者： CHEN Jiajia ZHANG Liyong FU Yucan qian ning JIANG Huafei YANG Lin College of Mechanical and Electronic Engineering Nanjing Forestry UniversityNanjing 210037China College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China Jiangsu Wind Power Generation Engineering&Technology Center Nanjing 210023China

This study numerically analyzed the heat transfer characteristics outside the condenser of a rotating heat pipe grinding wheel(RHP-GW).The goal of this investigation is to determine the optimal structure and parameters for the condenser section of *** fin height(f=0-7 mm),rotational Reynolds number(Rer=1602-6408)and jet Reynolds number(Rej=42379-108302)were analyzed under input heat flux of 4000 W/m2.A fully developed flow was imposed at the outlet of the *** showed that the optimal heat transfer rate was obtained for fin height of 5 mm,which improved the average Nusselt number by 84%compared to the structure without fins.A critical Rej for each Rer that the impinging jet can reach the condenser section was *** critical Rej value increases with Rer,which is in the range from 42379 to 61215 and 61215 to 80050 for Rer=6408 and Rer=9610,respectively.

关键词： rotating heat pipe grinding wheel impinging jet heat transfer numerical analysis

Distributions of Visual Receptive Fields from Retinotopic to Craniotopic Coordinates in the Lateral Intraparietal Area and Frontal Eye Fields of the Macaque

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Neuroscience Bulletin 2024年第2期40卷 171-181页

作者： Lin Yang Min Jin Cong Zhang ning qian Mingsha Zhang Key Laboratory of Cognitive Neuroscience and Learning Division of PsychologyBeijing Normal UniversityBeijing 100875China Institute of Neuroscience Key Laboratory of Primate NeurobiologyCAS Center for Excellence in Brain Science and Intelligence TechnologyChinese Academy of SciencesShanghai 200031China Department of Neuroscience and Zuckerman Institute Columbia UniversityNew York 10027USA

Even though retinal images of objects change their locations following each eye movement,we perceive a stable and continuous *** possible mechanism by which the brain achieves such visual stability is to construct a craniotopic coordinate by integrating retinal and extraretinal *** have been several proposals on how this may be done,including eye-position modulation(gain fields)of retinotopic receptive fields(RFs)and craniotopic *** the present study,we investigated coordinate systems used by RFs in the lateral intraparietal(LIP)cortex and frontal eye fields(FEF)and compared the two *** mapped the two-dimensional RFs of neurons in detail under two eye fixations and analyzed how the RF of a given neuron changes with eye position to determine its coordinate *** same recording and analysis procedures were applied to the two brain *** found that,in both areas,RFs were distributed from retinotopic to craniotopic *** was no significant difference between the distributions in the LIP and *** a small fraction of neurons was fully craniotopic,whereas most neurons were between the retinotopic and craniotopic *** distributions were strongly biased toward the retinotopic side but with significant craniotopic *** results suggest that there is only weak evidence for craniotopic RFs in the LIP and FEF,and that transformation from retinotopic to craniotopic coordinates in these areas must rely on other factors such as gain fields.

关键词： Reference frames Eye-centered Headcentered Visual stability

Pulsed Unipolar-Polarisation Plasma Electrolytic Polishing of Ni-Based Superalloys: A Proof of Conception

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CHINESE JOURNAL OF MECHANICAL ENGINEERING 2024年第1期37卷 1-17页

作者： Zhou, Chuanqiang qian, ning Su, Honghua He, Jingyuan Ding, Wenfeng Xu, Jiuhua Nanjing Univ Aeronaut & Astronaut Jiangsu Key Lab Precis & Micromfg Technol Nanjing 210016 Peoples R China JITRI Inst Precis Mfg Nanjing 211806 Peoples R China

The enhanced performance of aerospace equipment drives parts development towards integration, complexity, and structural optimization. This advancement promotes metal near-net fabrication technologies like wire electrical discharge machining (WEDM) and 3D printing. However, the high initial surface roughness from WEDM or 3D printing poses significant challenges for the high-performance surface finishing required. To effectively reduce the surface roughness of the workpieces with high initial surface roughness, this paper proposes pulsed unipolar-polarisation plasma electrolytic polishing (PUP-PEP). The study examined the material removal mechanisms and surface polishing quality of PUP-PEP. This technique combines the high current density and material removal rate of the electrolytic polishing mode with the superior surface polishing quality of PEP through voltage waveform modulation. For an Inconel-718 superalloy part fabricated by WEDM, PUP-PEP reduced surface roughness from Ra 7.39 mu m to Ra 0.27 mu m in 6 min under optimal conditions. The roughness decreased from Ra 7.39 mu m to Ra 0.78 mu m in the first 3 min under pulsed unipolar-polarisation voltage, resulting in a remarkable 233% increase in efficiency compared to that with conventional PEP. Subsequently, the voltage output voltage is transformed into a constant voltage mode, and PEP is continued based on PUP-PEP to finally reduce the workpiece surface roughness value to Ra 0.27 mu m. The proposed PUP-PEP technology marks the implementation of 'polishing' instead of conventional rough-finish machining processes, presenting a new approach to the surface post-processing of metal near-net fabrication technologies.

关键词： Pulsed unipolar-polarisation Plasma electrolytic polishing Voltage waveform Superalloy Surface roughness Material removal rate

Neck-spinning quality analysis and optimization of process parameters for plunger components:Simulation and experimental study

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Chinese Journal of Aeronautics 2021年第4期34卷 174-191页

作者： Yang WANG Honghua SU ning qian Kui LIU Jianbo DAI Zhengcai ZHAO Wenfeng DING College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China Singapore Institute of Manufacturing Technology 73 Nanyang DriveSingapore 637662Singapore School of Mechatronic Engineering China University of Mining and TechnologyXuzhou 221116China

The plunger component is a key part of the plunger pump in the aircraft hydraulic ***-spinning process is commonly used to fabricate plunger components,of which the quality of the spinning process significantly affects the performance of plunger *** of the bottlenecks faced by the industry in the spinning process is to choose a suitable neck-spinning process so as to ensure the quality of plunger *** is necessary to propose a reliable method to optimize the process parameters which affect the neck-spinning quality of plunger *** this study,a calculable finite element analysis(FEA)model is established to simulate the threeroller neck-spinning process of the plunger component,which includes six typical slipper structures,two roller structures,and two spinning *** FEA model is then validated by comparing the simulated spinning forces with the corresponding experimental *** influence of the process conditions on the neck-spinning quality is *** the orthogonal simulation results are analyzed by a combination of range method and fuzzy mathematical analysis method to recommend a reasonable slipper structure,roller structure and neck-spinning *** study provides a promising method to improve the manufacturing quality of the typical plunger components.

关键词： Fuzzy method Neck-spinning quality Plunger component Range analysis Simulation

Neuroimmune connections between corticotropinreleasing hormone and mast cells:novel strategies for the treatment of neurodegenerative diseases

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Neural Regeneration Research 2021年第11期16卷 2184-2197页

作者： Piplu Bhuiyan Yi-Wei Wang Huan-Huan Sha Hong-Quan Dong Yan-ning qian Department of Anesthesiology The First Affiliated Hospital of Nanjing Medical UniversityNanjingJiangsu ProvinceChina Department of Anesthesiology Wuxi People’s HospitalNanjing Medical UniversityWuxiJiangsu ProvinceChina

Corticotropin-releasing hormone is a critical component of the hypothalamic–pituitary–adrenal axis,which plays a major role in the body’s immune response to *** cells are both sensors and effectors in the interaction between the nervous and immune *** first responders to stress,mast cells can initiate,amplify and prolong neuroimmune responses upon ***-releasing hormone plays a pivotal role in triggering stress responses and related diseases by acting on its receptors in mast ***-releasing hormone can stimulate mast cell activation,influence the activation of immune cells by peripheral nerves and modulate neuroimmune *** latest evidence shows that the release of corticotropin-releasing hormone induces the degranulation of mast cells under stress conditions,leading to disruption of the bloodbrain barrier,which plays an important role in neurological diseases,such as Alzheimer’s disease,Parkinson’s disease,multiple sclerosis,autism spectrum disorder and amyotrophic lateral *** studies suggest that stress increases intestinal permeability and disrupts the blood-brain barrier through corticotropin-releasing hormone-mediated activation of mast cells,providing new insight into the complex interplay between the brain and gastrointestinal *** neuroimmune target of mast cells is the site at which the corticotropin-releasing hormone directly participates in the inflammatory responses of nerve *** this review,we focus on the neuroimmune connections between corticotropin-releasing hormone and mast cells,with the aim of providing novel potential therapeutic targets for inflammatory,autoimmune and nervous system diseases.

关键词： blood-brain barrier corticotropin-releasing hormone gastrointestinal tract inflammatory mast cells neuroimmune neurological disorders

Towards Sustainable Grinding of Difficult-to-Cut Alloys-A Holistic Review and Trends

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Chinese Journal of Mechanical Engineering 2024年第2期37卷 1-28页

作者： ning qian Jiajia Chen Aqib Mashood Khan Biao Zhao Yurong Chen Wenfeng Ding Yucan Fu Jiuhua Xu Jiangsu Key Laboratory of Precision and Micro-Manufacturing Technology Nanjing University of Aeronautics and AstronauticsNanjing 210016China College of Mechanical and Electronic Engineering Nanjing Forestry UniversityNanjing 210037China JITRI Institute of Precision Manufacturing Nanjing 211805China

Grinding,a critical precision machining process for difficult-to-cut alloys,has undergone continual technological advancements to improve machining ***,the sustainability of this process is gaining heightened attention due to significant challenges associated with the substantial specific grinding energy and the extensive heat generated when working with difficult-to-cut alloys,renowned for their exceptional physical and mechanical *** response to these challenges,the widespread application of massive coolant in manufacturing industries to dissipate grinding heat has led to complex post-cleaning and disposal ***,in turn,has resulted in issues such as large energy consumption,a considerable carbon footprint,and concerns related to worker health and safety,which have become the main factors that restrict the development of grinding *** paper provides a holistic review of sustainability in grinding difficult-to-cut alloys,encompassing current trends and future *** examination extends to developing grinding technologies explicitly tailored for these alloys,comprehensively evaluating their sustainability ***,the exploration delves into innovative sustainable technologies,such as heat pipe/oscillating heat pipe grinding wheels,minimum quantity lubrication,cryogenic cooling,and *** groundbreaking technologies aim to reduce dependence on hazardous coolants,minimizing energy and resource consumption and carbon emissions associated with coolant-related or subsequent disposal *** essence of these technologies lies in their potential to revolutionize traditional grinding practices,presenting environmentally friendly ***,future development trends and research directions are put forward to pursue the current limitation of sustainable grinding for difficult-to-cut *** paper can guide future research and development efforts toward more environmentally friendly

关键词： Grinding Sustainability Cooling Energy consumption Carbon footprint Difficult-to-cut alloys

A Study on Correlation Between Car Use Tax and Urban Space Development:Based on Bid Rent Function of Urban Land-use

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China City Planning Review 2011年第2期20卷 23-31页

作者： DU ning qian Fang

Based on the model of the bid rent function in a mono-centric city,this paper,by introducing the concept of opportunity cost and extending partial equilibrium analysis to general equilibrium analysis,conducts a theoretical analysis on the possibility that the typical car use taxes including fuel consumption tax,traffic congestion tax,and parking tax can affect the urban space development through their impact on transport cost and the rent bid under certain *** conclusions drawn from the comparison might be useful when it comes to the practical problems of urban space development.

关键词： tax bid rent function urban space development

Origin,discovery,exploration and development status and prospect of global natural hydrogen under the background of“carbon neutrality”

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China Geology 2022年第4期5卷 722-733页

作者： qian-ning Tian Shu-qing Yao Ming-juan Shao Wei Zhang Hai-hua Wang Geoscience Documentation Center China Geological SurveyMinistry of Natural ResourcesBeijing 100083China National Geological Library of Chin1 2eijing 100083China

Global energy structure is experiencing the third transition from fossil energy to non-fossil energy,to solve future energy problems,cope with climate change,and achieve net-zero emissions targets by *** is considered to be the most potential clean energy in this century under the background of carbon *** present,the industrial methods for producing hydrogen are mainly by steam-hydrocarbon(such as coal and natural gas)reforming and by electrolysis of water,while the exploration and development of natural hydrogen had just *** to this literature review:(1)Natural hydrogen can be divided into three categories,including free hydrogen,hydrogen in inclusions and dissolved hydrogen;(2)natural hydrogen could be mainly from abiotic origins such as by deep-seated hydrogen generation,water-rock reaction or water radiolysis;(3)natural hydrogen is widely distributed and presents great potential,and the potential natural hydrogen sources excluding deep source of hydrogen is about(254±91)×10^(9) m^(3)/a according to a latest estimate;(4)at present,natural hydrogen has been mined in Mali,and the exploration and development of natural hydrogen has also been carried out in Australia,Brazil,the United States and some European countries,to find many favorable areas and test some technical methods for natural hydrogen *** hydrogen is expected to be an important part of hydrogen energy production in the future energy *** on a thorough literature review,this study introduced the origin,classification,and global discovery of natural hydrogen,as well as summarized the current global status and discussed the possibility of natural hydrogen exploration and development,aiming to provide reference for the future natural hydrogen exploration and development.

关键词： Carbon neutrality Energy transition New energy Hydrogen energy Natural hydrogen Occurrence Genesis Resources Exploration and development Potential

Respect and Protection:A Review of the Implementation of the Law of the P.R.C. on the Protection of Rights and Interests of Women

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Women of China 1995年第5期 24-26页

作者： LIU qian ZHAO ning

JIANG Zemin, President of the People’s Republic of China, once said: "Respecting women and protecting women is an important sign of social progress. It should become a civilized society’s legal provision and moral concept." On October 1, 1992 the Law of the P.R.C. on the Protection of Rights and Interests of Women was put into effect, which was considered a major accomplishment for China and Chinese women. More than two years have passed since the implementation of the law. How well has the law

关键词： on the Protection of Rights and Interests of Women Respect and Protection:A Review of the Implementation of the Law of the P.R.C