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Study on the adaptability of augmented reality smartglasses for astigmatism based on holographic waveguide grating

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Virtual Reality & Intelligent Hardware 2020年第1期2卷 79-85页

作者： Shenze WANG Kaikai DU Ningfang SONG Dongfeng ZHAO Di FENG Zhengqian TU Beihang University Beijing 100083China Qingdao Research Institute of Beihang University Qingdao 266100ShandongChina Goertek co. Ltd.Qingdao 266100ShandongChina

Background Augmen ted reality(AR)smartglasses are co.sidered as the next generation of smart devices to replace mobile phones,and are widely *** at present,AR smartglasses are usually designed acco.ding to the human normal *** order to experience AR smartglasses perfectly,abnormal eye users must first wear *** For people with astigmatism to use AR smartglasses without wearing a diopter lens,a cylindrical lens waveguide grating is designed in this study based on the principle of holographic waveguide ***,a cylindrical lens waveguide substrate is co.structed for external light deflection to satisfy the users'normal viewing of the real ***,a variable period grating structure is established based on the cylindrical lens waveguide substrate to normally emit the light from the virtual world in the optical machine to the human ***,the structural parameters of grating are optimized to improve the diffraction *** The results show that the structure of cylindrical lens waveguide grating allows people with astigmatism to wear AR smartglasses *** total light utilization rate reaches 90%with excellent imaging *** brightness difference is less than 0.92%and the vertical field of view is 10°.co.clusions This research serves as a guide for AR product designs for people with long/short sightedness and promotes the development of such products.

关键词： Holographic waveguide grating Augmented reality smartglasses Cylindrical lens Astigmatism

Biological Stability of Water-Based Cutting Fluids:Progress and Application

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Chinese Journal of Mechanical Engineering 2022年第1期35卷 7-30页

作者： Lizhi Tang Yanbin Zhang Changhe Li Zongming Zhou Xiaolin Nie Yun Chen Huajun Cao Bo Liu Naiqing Zhang Zafar Said Sujan Debnath Muhammad Jamil Hafiz Muhammad Ali Shubham Sharma School of Mechanical and Automotive Engineering Qingdao University of TechnologyQingdao 266520China Hanergy(Qingdao)Lubrication Technology co. Ltd.Qingdao 266200China Nanjing Kerun Lubricants co. Ltd.Nanjing 211106China Chengdu Tool Research Institute co. LtdChengdu 610500China School of Mechanical Engineering Chongqing UniversityChongqing 400044China Sichuan Future Aerospace Industry LLC Shifang 618400China Shanghai Jinzhao Energy Saving Technology co. Ltd.Shanghai 200436China Department of Sustainable and Renewable Energy Engineering University of Sharjah27272 SharjahUnited Arab Emirates Mechanical Engineering Department Curtin University98009 MiriMalaysia co.lege of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China Mechanical Engineering Department King Fahd University of Petroleum and MineralsDhahran 31261Saudi Arabia Department of Mechanical Engineering IK Gujral Punjab Technical UniversityKapurthala 144603PunjabIndia

The application of cutting fluid in the field of engineering manufacturing has a history of hundreds of years,and it plays a vital role in the processing efficiency and surface quality of *** them,water-based cutting fluid acco.nts for more than 90%of the co.sumption of cutting ***,long-term recycling of water-based cutting fluid co.ld easily cause deterioration,and the breeding of bacteria co.ld cause the cutting fluid to fail,increase manufacturing co.ts,and even endanger the health of *** bactericides co.ld improve the biological stability of cutting fluids,but they are toxic to the environment and do not co.form to the development trend of low-carbon ***-carbon manufacturing is inevitable and the direction of sustainable *** use of nanomaterials,transition metal co.plexes,and physical sterilization methods on the bacterial cell membrane and genetic material co.ld effectively solve this *** this article,the mechanism of action of additives and microbial metabolites was first ***,the denaturation mechanism of traditional bactericides on the target protein and the effect of sterilization efficiency were ***,the mechanism of nanomaterials disrupting cell membrane potential was *** effects of lipophilicity and the atomic number of transition metal co.plexes on cell membrane penetration were also summarized,and the effects of ultraviolet rays and ozone on the destruction of bacterial genetic material were *** other words,the bactericidal performance,hazard,degradability,and eco.omics of various sterilization methods were co.prehensively evaluated,and the potential development direction of improving the biological stability of cutting fluid was proposed.

关键词： Cutting fluid Microorganism Bactericide Sterilization

Technology and Experiments of 42CrMo Bearing Ring Forming Based on Casting Ring Blank

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Chinese Journal of Mechanical Engineering 2014年第2期27卷 418-427页

作者： LI Yongtang JU Li QI Huiping ZHANG Feng CHEN Guozhen WANG Mingli School of Material Science and Engineering Taiyuan University of Science and Technology Luoyang LYC Bearing co. Ltd

Bearing ring is the crucial co.ponent of bearing. With regard to such problems as material waste, low efficiency and high energy co.sumption in current process of producing large bearing ring, a new process named ＂casting-rolling co.pound forming technology＂ is researched by taking the typical 42CrMo slew bearing as object. Through theoretical analysis, the design criteria of the main casting-rolling forming parameters are put forward at first. Then the co.stitutive relationship model of as-cast 42CrMo steel and its mathematical model of dynamic recrystallization are obtained acco.ding to the results of the hot co.pression experiment. By a co.pled thermal-mechanical finite element model for radial-axial rolling of bearing ring, the fraction of dynamic recrystallization is calculated and recrystallized grains size are predicated. Meanwhile, the effects of the initial rolling temperature and feed rate of idle roll on material microstructure evolution are analyzed. Finally, the industrial rolling experiment is designed and performed, based on the simulation results. In addition, mechanical and metallographic tests are co.ducted on rolled bearing ring to get the mechanical parameters and metallographic structure. The experimental data and results show that the mechanical properties of bearing ring produced by casting-rolling co.pound forming technology are up to industrial standard, and a qualified bearing ring can be successfully formed by employing this new technology. Through the study, a process of forming large bearing ring directly by using casting ring blank is obtained, which co.ld provide an effective theoretical guidance for manufacturing large ring parts. It also has an edge in saving material, lowering energy and improving efficiency.

关键词： bearing ring 42CrMo casting ring blank casting-rolling co.pound forming microstructure evolution

Multi-Layer Reco.struction Errors Autoenco.ing and Density Estimate for Network Anomaly Detection

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co.puter Modeling in Engineering & Sciences 2021年第7期128卷 381-397页

作者： Ruikun Li Yun Li Wen He Lirong Chen Jianchao Luo University of Electronic Science and Technology of China Chengdu611730China Guangdong Weichen Information Technology co. Ltd.Guangzhou510000China Chongqing Changan Automobile co.poration Chongqing400000China

Anomaly detection is an important method for intrusion *** recent years,unsupervised methods have been widely researched because they do not require *** example,a nonlinear autoenco.er can use reco.struction errors to attain the discrimination *** method is not effective when the model co.plexity is high or the data co.tains *** method for detecting the density of co.pressed features in a hidden layer can be used to reduce the influence of noise on the selection of the threshold because the density of abnormal data in hidden layers is smaller than normal ***,co.pressed features may lose some of the high-dimensional distribution information of the original *** this paper,we present an efficient anomaly detection framework for unsupervised anomaly detection,which includes network data capturing,processing,feature extraction,and anomaly *** employ a deep autoenco.er to obtain co.pressed features and multi-layer reco.struction errors,and feeds them the same to the Gaussian mixture model to estimate the *** proposed approach is trained and tested on multiple current intrusion detection datasets and real network scenes,and performance indicators,namely accuracy,recall,and F1-sco.e,are better than other autoenco.er models.

关键词： Anomaly detection deep autoenco.er density estimate

Research on Phase-Shifted Full-Bridge Circuit Based on Frequency and Phase-Shift Synthesis Modulation Strategy

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Energy Engineering 2022年第2期119卷 699-721页

作者： Mingda Jiang Yanbo Che Hongfeng Li Muhammad Ishaq Chao Xing Key Laboratory of Smart Grid of Education Ministry Tianjin UniversityTianjinChina Electric Power Research Institute of Yunnan Power Grid co. Ltd.KunmingChina

The full-bridge co.verters usually use transformer leakage inductance and parallel resonant capacitors to achieve smooth current co.mutation and soft switching functions,which can easily cause problems such as energy leakage and significant duty cycle *** paper designs a novel full-bridge zero-current(FB-ZCS)co.verter with series resonant capacitors and proposes a frequency and phase-shift synthesis modulation(FPSSM)co.trol strategy based on this *** with the traditional parallel resonant capacitor circuit,the passive co.ponents used are significantly reduced,the structure is simple,and there is only a slight energy *** co.trolling the charging time of the capacitor,it can be achieved without additional switches or auxiliary *** automatic co.trol of capacitor energy based on input current addresses the low efficiency of the traditional co.trol *** paper introduces its principle in detail and verifies it through ***,an experimental prototype was built further to demonstrate the feasibility of the theory through *** module can be applied to a photovoltaic DC co.lection system using input parallel output series(IPOS)cascade to provide a new topology for large-scale,long-distance DC transmission.

关键词： Full-bridge co.verter frequency and phase-shift synthesis modulation(FPSSM) photovoltaic DC co.lection system co.trol strategy

Evaluation of the performance of a centralized ground-water heat pump system in co.d climate region

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Frontiers in Energy 2014年第3期8卷 394-402页

作者： Shilei LU Zhe CAI Yiran LI Li ZHANG School of Environmental Science and Engineering Tianjin University Tianjin 300072 China China Aerospace co.struction Group co. Ltd. Beijing 100071 China

The aim of this study is to performance of a centralized open-loop evaluate the ground-water heat pump （GWHP） system for climate co.ditioning in Beijing with a co.d climate in China. Thus, a long-time test was co.ducted on a running GWHP system for the heating season from December 2011 to March 2012. The analysis of the testing data indicates that the average heat-pump co.fficient of performance （co.） and the co. of the system （co.s） are 4.27 and 2.59. The low value and large fluctuation in the range of co. are found to be caused by the heat transfixion in the aquifer and the bypass in the circulation loop. Therefore, some suggestions are proposed to improve the performance for GWHPs in the co.d climate region in China.

关键词： ground-water heat pump (GWHP) actualco.fficient of performance heat transfixion

Formation of Polytypoids(12H and 21R)in High Temperature Nitrogen Atmosphere and Their Effects on SiC-MgAl_(2)O_(4) co.posites

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China's Refractories 2023年第2期32卷 45-50页

作者： GU Chenwei WANG Zhanmin ZHAO Shixian SI Yaochen XIA Miao State Key Laboratory of Advanced Refractories Sinosteel Luoyang Institute of Refractories Research Co.Ltd.Luoyang 471039China

SiC-MgAl_(2)O_(4) co.posites with SiAlON polytypoids(12H and 21R)as the bonding phases were prepared using SiC fine powder,MgAl_(2)O_(4)fine powder and Al powder as raw *** effects of the firing temperature and the mass ratio of SiC to MgAl_(2)O_(4) on the formation of SiAlON polytypoids as well as on the properties of samples were *** formation mechanism of SiAlON polytypoids was *** results show that firing at 1650℃in the nitrogen atmosphere,SiC-MgAl_(2)O_(4) co.posites with SiAlON polytypoids can be *** the gradual increase of the mass ratio of SiC to MgAl_(2)O_(4) in the raw materials,12H forms first,and then co.xists with 21H,finally,all 12H co.verts into 21R in *** phases are plate crystals with flat and smooth *** with 21R,12H is co.ducive to improving the density and the co.d mechanical properties of *** firing at 1650℃in the nitrogen atmosphere,with the mass ratio of SiC to MgAl_(2)O_(4) of 6:4,the sample has the co.d modulus of rupture of 27 MPa,showing the optimal performance.

关键词： silico. carbide MgAl_(2)O_(4) silico. carbide-MgAl_(2)O_(4)co.posites SiAION polytypoids 12H 21R

Detection technology of micro residual co.e in small inner cavity of co.plex castings

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China Foundry 2018年第4期15卷 307-313页

作者： jun-hao zhao shi-ping wu yin dong tao-qi chang school of material science and engineering harbin institute of technologyHarbin 150001China avic xi'an aero-engine precision casting co. ltd.Xi'an 710021China

A new technology for detecting a tiny residual co.e in the small inner cavity of co.plex castings is proposed. The residual co.e is identified by using image reco.nition technology. Tracer processing and image signal processing are co.bined to enhance the image co.trast. The relationships between the co.centration of tracer, the size of the residual co.e, the wall thickness of the castings and the co.trast were obtained. Based on the experimental data, the minimum detectable amount of residual co.e under different co.ditions was obtained. The results show that the minimum detectable amount decreases from 4.398 mg to 0.438 mg for the 1.0 mm wall thickness casting when the co.centration of tracer increases from 0% to 20%. The signal-to-noise ratio(SNR) of the detection results increases by 27.010 by means of average filtering and linear point operation. The subtraction of image and image background was performed, and then the boundary extraction was carried out to obtain a clear and reliable result. The experimental results show that the non-traced residual co.e cannot be detected for a blade with a thickness less than 5 mm. The residual co.e of 1 mm thickness can be barely identified by artificial reco.nition after tracer processing and image processing, while the residual co.e of 0.6 mm thickness can be detected clearly using image reco.nition technology.

关键词： hollow blades X-ray detection residual ceramic co.e tracer image processing

co.parative Study of Earing Behavior in co.d Rolled-batch Annealed and co.d Rolled-co.tinuous Annealed of DoubleReduced (DR) Tinplate Steels

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Journal of Harbin Institute of Technology(New Series) 2019年第2期26卷 48-54页

作者： Xiaofei Zheng Yan Yan Yonglin Kang School of Materials Science and Engineering University of Science and Technology Beijing Shougang Jingtang Iron and Steel United co. Ltd.

Two double co.d reduction-drawn and redrawn(DRD) tinplate steels of the same chemistries that have been processed by co.tinuous and batch annealing line have been researched. The co.position of fibers were studied through X-ray diffraction. The results indicate that a strong intensity of {114} was formed in the co.tinuous annealing steel and a strong intensity of {111} was formed in the batch annealing steel; not only that but the γ fiber slowly rotated to the low angel α fiber with the angel being about 30° nearly {112}texture owing to the higher seco.d reduction.

关键词： earing behavior annealing process texture double co.d reduction-drawn and redrawn(DRD)