Mingjin Xu

Ministry of Agriculture and Rural Affairs

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Trends

Author Order

Document Type

Co-Authors

Yifan Dai

National University of Defense Technology

Lin Zhou

Harbin University of Commerce

Xuhui Xie

Huazhong University of Science and Technology

Yaoyu Zhong

Academy of Military Medical Sciences

Wenlin Liao

China Aerodynamics Research and Development Center

Xiaoqiang Peng

National University of Defense Technology

Feng Shi

National University of Defense Technology

Zhaoliang Wu

Chongqing University

Weibin Wu

University of Shanghai for Science and Technology

Yifan Dai

National University of Defense Technology

Cooperative Institutions

National University of Defense Technology

Naval University of Engineering

Ministry of Agriculture and Rural Affairs

Ningbo University

Chinese Academy of Sciences

General Electric (Finland)

Academy of Military Medical Sciences

Xi'an Jiaotong University

China Aerodynamics Research and Development Center

Chongqing University

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Field

Investigation of surface damage precursor evolutions and laser-induced damage threshold improvement mechanism during Ion beam etching of fused silica

Optics Express (2016)

Feng Shi Yaoyu Zhong Yifan Dai Xiaoqiang Peng Mingjin Xu

Surface damage precursor evolution has great influence on laser-induced damage threshold improvement of fused silica surface during Ion beam etching. In this work, a series of ion sputtering experiment are carried out to obtain the evolutions of damage precursors (dot-form microstructures, Polishing-Induced Contamination, Hertz scratches, and roughness). Based on ion sputtering theory, surface damage precursor evolutions are analyzed. The results show that the dot-form microstructures will appear during ion beam etching. But as the ion beam etching depth goes up, the dot-form microstructures can be mitigated. And ion-beam etching can broaden and passivate the Hertz scratches without increasing roughness value. A super-smooth surface (0.238nm RMS) can be obtained finally. The relative content of Fe and Ce impurities both significantly reduce after ion beam etching. The laser-induced damage threshold of fused silica is improved by 34% after ion beam etching for 800nm. Research results can be a reference on using ion beam etching process technology to improve laser-induced damage threshold of fused silica optics.

Isotropic etching

10.1364/oe.24.020842

Cite

Citations (35)

Interfacial film properties of asphaltenes and resins

Fuel (2002)

Mingyuan Li Mingjin Xu Yu Ma Zhaoliang Wu Alfred A. Christy

Asphaltene

10.1016/s0016-2361(02)00050-9

Cite

Citations (62)

Optimization technique for rolled edge control process based on the acentric tool influence functions

Applied Optics (2017)

Hang Du Ci Song Shengyi Li Mingjin Xu Xiaoqiang Peng

In the process of computer controlled optical surfacing (CCOS), the uncontrollable rolled edge restricts further improvements of the machining accuracy and efficiency. Two reasons are responsible for the rolled edge problem during small tool polishing. One is that the edge areas cannot be processed because of the orbit movement. The other is that changing the tool influence function (TIF) is difficult to compensate for in algorithms, since pressure step appears in the local pressure distribution at the surface edge. In this paper, an acentric tool influence function (A-TIF) is designed to remove the rolled edge after CCOS polishing. The model of A-TIF is analyzed theoretically, and a control point translation dwell time algorithm is used to verify that the full aperture of the workpiece can be covered by the peak removal point of the tool influence functions. Thus, surface residual error in the full aperture can be effectively corrected. Finally, the experiments are carried out. Two fused silica glass samples of 100 mm×100 mm are polished by traditional CCOS and the A-TIF method, respectively. The rolled edge was clearly produced in the sample polished by the traditional CCOS, while residual errors do not show this problem the sample polished by the A-TIF method. Therefore, the rolled edge caused by the traditional CCOS process is successfully suppressed during the A-TIF process. The ability to suppress the rolled edge of the designed A-TIF has been confirmed.

Acentric factor

Aperture (computer memory)

Dwell time

10.1364/ao.56.004330

Cite

Citations (9)

Mechanism of Surface Hydroxylation Acceleration and Laser-Induced Damage Threshold Reduction during Ion Beam Sputtering of Fused Silica

Applied Sciences (2024)

Mingjin Xu Weibin Wu Yongsheng Ke Xiaohong Liu Yaoyu Zhong

The mechanism of the combined process of ion beam sputtering (IBS) and HF acid etching on the chemical structure defects of fused silica and its laser damage resistance performance were investigated in this paper. During the removal process of surface material, the sputtering effect causes lattice atoms to flee their native space locations, and a large amount of unsaturated chemical structures are produced on the silica surface, which improves the chemical activity of Si and O atoms, accelerates the chemical reaction process between surface atoms and water molecules, increases the content of hydroxyl groups (OH-) in the shallow layer, and enhances the photothermal weak absorption intensity. However, the increase in hydroxyl content weakens the binding strength of silicon–oxygen bonds, destroys the spatial network structure of silica bulk, and reduces its mechanical strength, resulting in a decrease in its laser damage resistance performance. The paper reveals for the first time the mechanism by which IBS changes the structure characteristics of silica material, accelerates the surface hydroxylation process, and thereby reduces the laser damage resistance performance. This work provides technical guidance for effectively suppressing chemical structure defects on silica surfaces and improving the laser damage resistance performance of optical components under high-flux laser irradiation.

10.3390/app14114550

Cite

Citations (1)

The Effect of HPAM on Crude Oil/Water Interfacial Properties and the Stability of Crude Oil Emulsions

Journal of Dispersion Science and Technology (2006)

Mingyuan Li Mingjin Xu Meiqin Lin Zhaoliang Wu

The influence of HPAM on interfacial properties and stability of the emulsions formed by formation water and asphaltene, resin, and crude model oils from Gudong crude oil was investigated by measurement of interfacial shear viscosity, interfacial tension, Zeta potential, and emulsion stability. HPAM may be adsorbed at the interface between the model oils and water, but the interfacial tension is not decreased. With increasing HPAM concentration, the interfacial shear viscosity, Zeta potential, and emulsion stability of the model oils system is increased. The o/w emulsion stability was enhanced with the polymer by steric and electrostatic stabilization.

Zeta potential

Asphaltene

Oil droplet

10.1080/01932690600992829

Cite

Citations (27)

Research on material removal accuracy analysis and correction of removal function during ion beam figuring

Optical Engineering (2016)

Weibin Wu Yifan Dai Lin Zhou Mingjin Xu

Material removal accuracy has a direct impact on the machining precision and efficiency of ion beam figuring. By analyzing the factors suppressing the improvement of material removal accuracy, we conclude that correcting the removal function deviation and reducing the removal material amount during each iterative process could help to improve material removal accuracy. Removal function correcting principle can effectively compensate removal function deviation between actual figuring and simulated processes, while experiments indicate that material removal accuracy decreases with a long machining time, so a small amount of removal material in each iterative process is suggested. However, more clamping and measuring steps will be introduced in this way, which will also generate machining errors and suppress the improvement of material removal accuracy. On this account, a free-measurement iterative process method is put forward to improve material removal accuracy and figuring efficiency by using less measuring and clamping steps. Finally, an experiment on a φ 100-mm Zerodur planar is preformed, which shows that, in similar figuring time, three free-measurement iterative processes could improve the material removal accuracy and the surface error convergence rate by 62.5% and 17.6%, respectively, compared with a single iterative process.

Figuring

10.1117/1.oe.55.9.095101

Cite

Citations (3)

Facile Fabrication of Superhydrophobic and Superoleophilic Polyurethane Foil with Micropillar and Microporous Structures for Efficient Oil/Water Separation

Applied Sciences (2024)

Weibin Wu Mingjin Xu Qinqin Wang Xue Yang Changgeng Shuai

Oil spill cleanup in water remains a critical challenge due to the harmful secondary pollution from conventional methods such as burning or chemical degradation. Herein, we present a facile method to fabricate a superhydrophobic and superoleophilic polyurethane (PU) foil for efficient and environmentally friendly oil/water separation. More specifically, micropillar arrays were embedded onto the foil surface through a nanoimprinting process. Microporous structures were generated at the foil cross-section by a supercritical carbon dioxide (CO2) saturation method. The dimensions of pillar and pore structures were optimized with the aim of boosting selective wetting (i.e., water repellency and oil attraction) properties. As a result, the developed PU foil shows an oil absorption efficiency nearly 4 times higher than a pristine reference. Moreover, the structured PU foil stably retains the absorbed oil for over a week, demonstrating an absorption capacity of nearly 400%, which is also much superior than the unstructured sample. Our concept of combining both topographical micropillars and cross-sectional micropores onto PU foil provides a novel approach for achieving efficient and environmental friendly oil/water separation.

10.3390/app14093935

Cite

Citations (1)

Evolution mechanism of surface roughness during ion beam sputtering of fused silica

Applied Optics (2018)

Mingjin Xu Yifan Dai Lin Zhou Xiaoqiang Peng Shaoshan Chen

Ultrasmooth surfaces with sub-nanometer roughness and low damage are a great challenge for optical fabrication. Ion beam sputtering (IBS) has obvious advantages on the improvement of surface quality and the removal of surface defects. However, surface defects with different properties and structures display different evolution laws during the IBS process, which affects the roughness change and needs classification studies. In this paper, classification experiments are carried out to study the surface topography evolution of plastic scratches, brittle scratches, and micro-particles during the IBS process. The plastic scratches and micro-particles can be removed, while the brittle scratches can be passivated, so that surface defects can be reduced and surface quality improved. The corresponding evolution mechanisms are discussed in depth, and we show that micro-topography characteristics and material properties are important factors affecting the evolution of surface topography. Through the summary of evolution laws of different surface states, the Gaussian distribution law of surface roughness is established. The evolution regularity and mechanism of surface roughness during the IBS process are expounded upon from the perspective of microscopic morphology, which lays a foundation for ultra-smooth surface manufacturing with low damage.

Brittleness

10.1364/ao.57.005566

Cite

Citations (20)

Dwelling time calculation for film uniformity correction by ion beam sputtering process on larger optical materials

Journal of Physics Conference Series (2020)

D S Wang Xinrui Li Fei-Fei Nie Si-Jia Zhao Mingjin Xu

Abstract It is difficult to obtain film with uniform thickness and constant performance for optical components with larger diameter. It is a critical technology to improve the film uniformity during the deposition process. The ion beam sputtering system was used to prepare the film on the surface of large-aperture optical elements. The performance of film including thickness and roughness were measured by step profiler and optical profilometer instrument. The film thickness correction model was proposed in this paper. The optimized dwell time ratio was obtained by the film thickness data obtained from former experiments, and the dwell time distribution was calculated, after several iteration with the model, uniform film can be achieved on optical elements over 300mm in diameter. Taking the Si film on the surface of fused silica as an example. The research results show that, different film thickness between 100nm and 400nm can be obtained, when the film thickness is more than 200 nm, the film uniformity from more than 13% to less than 0.5%. The surface roughness variation of optical material before and after film deposition were studied, which provide stable process for obtaining high performance film on larger optical components.

Dwell time

Deposition

Aperture (computer memory)

10.1088/1742-6596/1507/10/102003

Cite

Citations (0)

Structure optimization and fabricating capability analysis of an ion-beam machine for a subnanometer optical surface

Applied Optics (2015)

Mingjin Xu Yifan Dai Xuhui Xie Lin Zhou Wenlin Liao

Ultraprecise and ultrasmooth surfaces become critical requirements for some high-performance optical systems. Ion-beam figuring (IBF) is a good and highly deterministic method for the final precision optical figuring. However, the uniform convergences of all spatial frequency surface errors are strongly dependent on the dynamic performance and ion-beam stability of the IBF machine. In this paper, only the dynamic performance is discussed, which is limited by the acceleration and velocity of the motion system. So we discuss these problems and their influences on figuring optical surfaces in detail. The structure optimization principle is based on the fabricating capability of ultraprecise surface errors in all spatial frequency ranges. With this requirement, the structure optimization of a quick-response platform is performed to improve its dynamic performance. Manufacturing experiments on a fused silica spherical concave surface (Φ135.7 mm, radius of curvature 340.5 mm) are accomplished, and the IBF machine can effectively correct the figure errors and improve the surface quality simultaneously. The IBF process realizes the uniform convergence of surface errors in all spatial frequency ranges, which is reduced down to 0.368 nm RMS, 0.204 nm RMS, and 0.087 nm RMS, respectively. The final results indicate that the performance of the new designed IBF machine meets the requirements well for the fabrication of a subnanometer optical surface.

Figuring

Radius of curvature

Spatial frequency

10.1364/ao.54.008055

Cite

Citations (17)