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Modeling and analysis for material removal and surface roughness in fluid jet polishing of optical glass

Friction 2024年第7期12卷 1548-1563页

作者： zhongchen cao Ming WANG Haitao LIU Tian HUANG Key Laboratory of Mechanism Theory and Equipment Design of Ministry of Education Tianjin UniversityTianjin 300072China School of Engineering The University of WarwickCoventry CV47ALUK

luid jet polishing(FJP)is a non-contact polishing technology that can fabricate free-form optical surfaces with sub-micron-level form accuracy and nano-level surface roughness,especially for hard and brittle *** surface generation model of FJP can be used to guide the determination and optimization of process parameters and is of great significance for understanding the evolution mechanism of surface ***,predictive models for the microscopic topography of polished surfaces are still *** study established a macroscopic surface profile model for predicting 3D material removal characteristics and surface texture by combining the 3D computer fluid dynamics(CFD)simulation model and single-particle erosion mechanism.A fractal theory-based erosion model has been built to calculate the material removal caused by the erosion of a single abrasive particle on the rough surface;thus,it predicts the micro-topography and surface roughness of the polished samples.A series of polishing experiments were conducted to analyze the feasibility and accuracy of the model quantitatively and study the influence mechanism of process parameters on the material removal characteristics and surface *** indicated that the models could well predict material removal and surface *** prediction accuracy of the surface roughness Ra and maximum removal depth is better than 91.6%and 90%,*** is also found that the material removal rate of FJP could reach 0.517 mm3/min,and the surface roughness convergence rate could reach 62.9%.

关键词： fluid jet polishing(FJP) computational fluid dynamics(CFD) material removal mechanism surface roughness theoretical model

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固结磨料确定性研磨表面生成建模与实验分析

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天津大学学报（自然科学与工程技术版） 2019年第9期52卷 917-931页

作者：林彬李凯隆曹中臣姜向敏黄田天津大学先进陶瓷与加工技术教育部重点实验室天津300350 天津大学机械工程学院天津300350

基于CCOS技术原理,提出高效、高可控性的固结磨料确定性研磨工艺.通过线研磨实验发现采用中心供给研磨液方式相比于传统四周供液方式有利于提高加工效率及表面质量.分析了工艺参数对加工后表面硬度的影响,通过扫描电镜观察研磨后的表面... 详细信息

基于CCOS技术原理,提出高效、高可控性的固结磨料确定性研磨工艺.通过线研磨实验发现采用中心供给研磨液方式相比于传统四周供液方式有利于提高加工效率及表面质量.分析了工艺参数对加工后表面硬度的影响,通过扫描电镜观察研磨后的表面形貌,分析固结磨料研磨的材料去除机制.通过不同参数线研磨实验验证了材料去除率与工具转速、载荷、时间呈线性关系,表明固结磨料研磨工艺的材料去除过程符合CCOS的卷积迭代原理.基于晶胞理论和磨粒粒径均匀的假设,建立了固结磨料研磨垫表面形貌的仿真模型.同时,模型考虑了磨粒浓度、磨粒粒度、研磨垫形状参数的影响.在固结磨料研磨垫形貌仿真数据的基础上,基于硬脆材料去除机理以及研磨垫与工件微观接触模型,考虑工件表面的力学性能,建立了一定参数条件下研磨垫与工件的接触间隙计算模型,进而建立了单点研磨去除斑模型.通过定点研磨实验验证了不同压力、转速、时长条件下单点研磨去除斑模型的准确性.将连续的研磨轨迹进行离散,考虑研磨垫形状、磨粒的尺寸和浓度、研磨工具的转速和承受的载荷、轨迹参数建立了总去除量与单点研磨去除量的卷积运算关系,提出固结磨料确定性研磨表面生成模型.开展不同参数下面研磨实验与表面仿真.结果表明,固结磨料确定性研磨表面生成模型能很好地预测不同参数下研磨去除的深度和研磨表面的残留误差,提高固结磨料研磨工艺的可控性.

关键词：固结磨料研磨工艺参数表面生成模型轨迹

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杯形砂轮磨削熔融石英玻璃机理与实验研究

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机械科学与技术 2019年第1期38卷 67-72页

作者：苏蕴华林彬曹中臣天津大学机械工程学院天津300350

熔融石英玻璃是一种工程领域常用的光学玻璃材料。针对在陶瓷材料端面快速磨削中具有广泛应用的杯形砂轮,综合考虑了磨削过程中的脆性断裂和对材料造成的冲击效应,基于单颗粒磨削理论对砂轮运动轨迹和去除效率理论建模分析。在此基础上... 详细信息

熔融石英玻璃是一种工程领域常用的光学玻璃材料。针对在陶瓷材料端面快速磨削中具有广泛应用的杯形砂轮,综合考虑了磨削过程中的脆性断裂和对材料造成的冲击效应,基于单颗粒磨削理论对砂轮运动轨迹和去除效率理论建模分析。在此基础上,对熔融石英玻璃材料进行多参数的单颗粒金刚石刻划实验,以验证理论预测模型,实际测得的磨削力数值与刻划后三维表面形貌,与理论分析结果吻合。结果表明,这一理论模型可以用于预测磨削力数值和优化加工参数。

关键词：杯形砂轮单颗粒磨削磨削力熔融石英玻璃表面形貌

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Zeros of Complete Symmetric Polynomials over Finite Fields

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Journal of Systems Science & Complexity 2024年第4期37卷 1772-1788页

作者： cao Wei School of Mathematics and Statistics Minnan Normal UniversityZhangzhou 363000China

Wan and Zhang(2021) obtained a nontrivial lower bound for the number of zeros of complete symmetric polynomials over finite fields,and proposed a problem whether their bound can be *** this paper,the author improves Wan-Zhang's bound from three *** proposed results are based on the estimates related to the number of certain permutations and the value sets of non-permutation polynomials associated to the complete symmetric *** the author believes that there are still possibilities to improve the bounds and hence Wan-Zhang's bound.

关键词： Complete symmetric polynomial finite field permutation polynomial value set

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Pt nanodendrites with a PtIr alloy surface structure exhibit excellent stability toward acidic hydrogen evolution reaction

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Nano Research 2024年第6期17卷 4844-4849页

作者： Chang Liu Zongnan Wei Minna cao Rong cao State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China University of Chinese Academy of Sciences Beijing 100049China Fujian Science and Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou 350108China

The development of effective and stable electrocatalysts for the hydrogen evolution reaction(HER)in acidic electrolytes is a significant *** this work,homogeneous Pt nanodendrites(Pt NDs)with a PtIr shell were successfully synthesized by a two-step wet chemical *** open three-dimensional(3D)dendritic structure exhibited exceptional electrocatalytic characteristics,exposing as many active sites as ***,by alloying Ir with Pt on the surface,catalytic activity was greatly enhanced while ensuring extremely high *** surface-enriched platinum nanodendritic catalysts(Pt@PtIr NDs)outperformed the control samples and the commercial *** acidic HER test,Pt@PtIr NDs had a lower overpotential(22 mV)than Pt NDs(26 mV)and commercial Pt/C(31 mV)at 10 mA/cm^(2),and the activity of Pt@PtIr NDs remained consistent even after undergoing a continuous durability test for at least 168 h,which was much superior to the performance of commercial Pt/C(10 h)under identical test *** study revealed that the application of 3D Pt dendritic metal alloys may offer a chance for the development of enhanced electrocatalysts in acidic HER.

关键词： Pt nanodendrites iridium high stability hydrogen evolution reaction alloy

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Quantitative phase imaging based on holography:trends and new perspectives

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Light(Science & Applications) 2024年第7期13卷 1235-1277页

作者： Zhengzhong Huang Liangcai cao Department of Precision Instrument Tsinghua UniversityBeijing 100084China

In 1948,Dennis Gabor proposed the concept of holography,providing a pioneering solution to a quantitative description of the optical *** 75 years of development,holographic imaging has become a powerful tool for optical wavefront measurement and quantitative phase *** emergence of this technology has given fresh energy to physics,biology,and materials *** holography(DH)possesses the quantitative advantages of wide-field,non-contact,precise,and dynamic measurement capability for *** has unique capabilities for the propagation of optical fields by measuring light scattering with phase *** offers quantitative visualization of the refractive index and thickness distribution of weak absorption samples,which plays a vital role in the pathophysiology of various diseases and the characterization of various *** provides a possibility to bridge the gap between the imaging and scattering *** propagation of wavefront is described by the complex *** complex-value in the complex-domain is reconstructed from the intensityvalue measurement by camera in the ***,we regard the process of holographic recording and reconstruction as a transformation between complex-domain and real-domain,and discuss the mathematics and physical principles of *** review the DH in underlying principles,technical approaches,and the breadth of *** conclude with emerging challenges and opportunities based on combining holographic imaging with other methodologies that expand the scope and utility of holographic imaging even *** multidisciplinary nature brings technology and application experts together in label-free cell biology,analytical chemistry,clinical sciences,wavefront sensing,and semiconductor production.

关键词： holographic phase precise

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Dynamic Setting Method of Assessment Indicators for Power Curves of Renewable Energy Sources Considering Scarcity of Reserve Resources

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Journal of Modern Power Systems and Clean Energy 2024年第1期12卷 101-114页

作者： Minghao cao Jilai Yu the Department of Electrical Engineering Harbin Institute of TechnologyHarbinChina

With the increasing proportion of renewable energy sources(RESs)in power grid,the reserve resource(RR)scarcity for correcting power deviation of RESs has become a potential ***,the power curve of RES needs to be more rigorously *** RR scarcity varies during different time periods,so the values of assessment indicators should be dynamically *** assessment indicators in this paper include two aspects,i.e.,deviation exemption ratio and penalty ***,this paper proposes a method for dynamically calculating the supply capacity and RR cost,primarily taking into account the operating status of thermal units,forecast information of RES,and load ***,after clarifying the logical relationship between the degree of RR scarcity and the values of assessment indicators,this paper establishes a mapping function between *** on this mapping function,a dynamic setting method for assessment indicators is *** the future,RES will generally be equipped with battery energy storage systems(BESSs).Reasonably utilizing BESSs to reduce the power deviation of RESs can increase the expected income of ***,this paper proposes a power curve optimization strategy for RESs considering self-owned *** case study demonstrates that the dynamic setting method of assessment indicators can increase the revenue of RESs while ensuring that the penalty fees paid by RESs to the grid are sufficient to cover the RR ***,the power curve optimization strategy can help RESs further increase income and fully utilize BESSs to reduce power deviation.

关键词： Renewable energy battery energy storage system(BESS) power curve assessment reserve service parameter setting

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Bioinspired Closed-loop CPG-based Control of a Robotic Manta for Autonomous Swimming

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Journal of Bionic Engineering 2024年第1期21卷 177-191页

作者： Yiwei Hao Yonghui cao Yingzhuo cao Xiong Mo Qiaogao Huang Lei Gong Guang Pan Yong cao School of Marine Science and Technology Northwestern Polytechnical UniversityXi'an 710072China Unmanned Vehicle Innovation Center Ningbo Institute of NPUNingbo 315103China Key Laboratory of Unmanned Underwater Vehicle Technology of Ministry of Industry and Information Technology Xi'an 710072China

Fish in nature exhibit a variety of swimming modes such as forward swimming,backward swimming,turning,pitching,etc.,enabling them to swim in complex scenes such as coral *** is still difficult for a robotic fish to swim autonomously in a confined area as a real ***,we develop an untethered robotic manta as an experimental platform,which consists of two flexible pectoral fins and a tail fin,with three infrared sensors installed on the front,left,and right sides of the head to sense the surrounding *** generate multiple swimming modes of the robotic manta and online switching of different modes,we design a closed-loop Central Pattern Generator(CPG)controller based on distance information and use a combination of phase difference and amplitude of the CPG model to achieve stable and rapid adjustment of yaw *** verify the autonomous swimming ability of the robotic manta in complex scenes,we design an experimental scenario with a concave *** experimental results show that the robotic manta can achieve forward swimming,backward swimming,in situ turning within the concave obstacle,and finally exit from the area safely while relying on the perception of external obstacles,which can provide insight into the autonomous exploration of complex scenes by the biomimetic robotic ***,the swimming ability of the robotic manta is verified by field tests.

关键词： Biomimetic robotic manta Central Pattern Generator Closed-loop control Backward swimming

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Multi-scenario land use prediction and layout optimization in Nanjing Metropolitan Area based on the PLUS model

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Journal of Geographical Sciences 2024年第7期34卷 1415-1436页

作者： cao Ji cao Weidong cao Yuhong WANG Xuewei ZHANG Yizhen MA Jinji School of Geography and Tourism Anhui Normal UniversityWuhuAnhui241002China School of Ecology and Environment Anhui Normal UniversityWuhuAnhui241002China

The metropolitan area is a crucial spatial element in promoting new urbanization in *** possesses theoretical and empirical value in the determination of the evolutionary patterns and development trends necessary for regional integration and high-quality *** study focused on Nanjing Metropolitan Area,the first national metropolitan area in China,and established three development scenarios by combining ecological–economic spatial conflict(EESC)zones and national key ecological functional *** scenarios simulate the spatial distribution of future land use and land cover change(LUCC)using the development zone planning function of the patch generation land use simulation(PLUS)*** results show that:(1)Between 2000 and 2020,the most prominent characteristics of land use change were largely the massive expansion of built-up land and the significant decline of farmland,while changes in the area of ecological land were less evident.(2)EESC areas experienced significant changes over the past 20 years,but the overall level of conflict was *** land was the main land use type in the lowest-conflict area,while built-up land was the main land use type in the highest-conflict area.(3)From 2030 to 2050,further expansion of built-up areas is expected,with continued decrease of *** regulation of these land use changes can be achieved through different development zone *** economic development scenario had the largest built-up land area,while the ecological protection scenario had the largest farmland *** study simulates the spatial pattern changes in the metropolitan area based on spatial conflict patterns and national main functional area planning process,providing a scientific reference for future spatial planning and management.

关键词： land use change spatial conflict patch-generating simulation land use prediction Nanjing Metropolitan Area

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Making the Complicated Simple:A Minimizing Carrier Strategy on Innovative Nanopesticides

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Nano-Micro Letters 2024年第10期16卷 31-46页

作者： Wenjie Shangguan Qiliang Huang Huiping Chen Yingying Zheng Pengyue Zhao Chong cao Manli Yu Yongsong cao Lidong cao State Key Laboratory for Biology of Plant Diseases and Insect Pests Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijing 100193People's Republic of China College of Plant Protection China Agricultural UniversityBeijing 100193People's Republic of China State Key Laboratory of Element-Organic Chemistry Department of Chemical BiologyCollege of ChemistryNankai UniversityTianjin 300071People's Republic of China

The flourishing progress in nanotechnology offers boundless opportunities for agriculture,particularly in the realm of nanopesticides research and ***,concerns have been raised regarding the human and environmental safety issues stemming from the unrestrained use of non-therapeutic nanomaterials in *** is also important to consider whether the current development strategy of nanopesticides based on nanocarriers can strike a balance between investment and return,and if the complex material composition genuinely improves the efficiency,safety,and circularity of ***,we introduced the concept of nanopesticides with minimizing carriers(NMC)prepared through prodrug design and molecular self-assembly emerging as practical tools to address the current limitations,and compared it with nanopesticides employing non-therapeutic nanomaterials as carriers(NNC).We further summarized the current development strategy of NMC and examined potential challenges in its preparation,performance,and ***,we asserted that the development of NMC systems can serve as the innovative driving force catalyzing a green and efficient revolution in nanopesticides,offering a way out of the current predicament.

关键词： Nanopesticides Green agrochemicals Self-assembly Nanomaterial safety Sustainable development strategies

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