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Morphology and features of Cambrian oncoids and responses to palaeogeography of the North China Platform

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Journal of Palaeogeography 2020年第2期9卷 150-167页

作者： En-Zhao Xiao Ming-Xiang Mei Shu Jiang Tehseen zafar School of Earth Sciences and Resources China University of Geosciences(Beijing)Beijing 100083China Key Laboratory of Tectonics and Petroleum Resources of Ministry of Education and Faculty of Earth Resources China University of Geosciences(Wuhan)Wuhan 430074China Institute of Geochemistry Chinese Academy of SciencesGuiyang 550081China Institute of Geology University of the PunjabLahore 54590Pakistan

The Cambrian strata in the North China Platform are fully exposed. A wide variety of carbonate oncoids with different shapes occur in the Xuzhuang and Zhangxia formations(Miaolingian Series) from six Cambrian sections in the study area. A comprehensive study involving outcrop description, microscopic observation, scanning electron microscopy(SEM), energy dispersive X-ray spectroscopy(EDX), X-ray diffraction(XRD), and carbon and oxygen isotope analysis is conducted to determine the facies, morphology, internal structure, and geochemical properties of the oncoids. The oncoids are divided into six types based on their morphology and internal *** and ultrastructural observations reveal typical microbial fossils(Girvanella) and microbially-related sediments(framboidal pyrite), indicating the biogenicity of the oncoids. Additionally, the XRD and carbon and oxygen isotope analysis results suggest that the formational environments of these oncoids are different due to terrestrial influences. Statistical data on the oncoids from the six sections show that there are obvious differences in the types of oncoids and the proportions of different varieties in each section. The spatial differences in the oncoid morphologies are associated with different palaeogeographic settings. The rough oncoid growth patterns developed in nearshore environments were influenced by terrigenous debris and steep terrain, whereas the delicate oncoid growth patterns developed in offshore environments were less affected by terrestrial factors and were featured by more stable depositional processes related to microbial mats.

关键词： Morphological classification Microbial m at Girvonello Carbon and oxygen isotopes Miaolingian series North China

High power supercontinuum generation by dual-color femtosecond laser pulses in fused silica

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Chinese Physics B 2022年第8期31卷 436-439页

作者： Saba zafar Dong-Wei Li Acner Camino Jun-Wei Chang Zuo-Qiang Hao Shandong Provincial Engineering and Technical Center of Light Manipulation&Shandong Provincial Key Laboratory of Optics and Photonic Device School of Physics and ElectronicsShandong Normal UniversityJinan 250358China Department of Physics Women University MardanMardan 23200Pakistan School of Science Changchun University of Science and TechnologyChangchun 130022China

High power supercontinuum(SC) is generated by focusing 800 nm and 400 nm femtosecond laser pulses in fused silica with a microlens array. It is found that the spectrum of the SC is getting broader compared with the case of a single laser pulse, and the spectral energy density between the two fundamental laser wavelengths is getting significantly higher by optimizing the phase matching angle of the BBO. It exceeds μJ/nm over 490 nm range which is from 380 nm to 870 nm,overcoming the disadvantage of relative lower power in the ranges far from the fundamental wavelength.

关键词： filamentation supercontinuum generation microlens array

Prediction model of volume average diameter and analysis of atomization characteristics in electrostatic atomization minimum quantity lubrication

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Friction 2023年第11期11卷 2107-2131页

作者： Dongzhou JIA Changhe LI Jiahao LIU Yanbin ZHANG Min YANG Teng GAO zafar SAID Shubham SHARMA School of Mechanical&Automotive Engineering Qingdao University of TechnologyQingdao 266520China College of Mechanical Engineering and Automation Liaoning University of TechnologyJinzhou 121001China State Key Laboratory of Ultra-precision Machining Technology Department of Industrial and Systems EngineeringThe Hong Kong Polytechnic UniversityHong Kong 999077China College of Engineering University of SharjahSharjah 27272United Arab Emirates Mechanical Engineering Department University Center for Research and DevelopmentChandigarh UniversityMohaliPunjab 144603India

Minimum quantity lubrication(MQL)is a relatively efficient and clean alternative to flooding workpiece *** atomization has the merits of small droplet diameter,high uniformity of droplet size,and strong coating,hence its superiority to pneumatic ***,as the current research hotspot,the influence of jet parameters and electrical parameters on the average diameter of droplets is not ***,by observing the shape of the liquid film at the nozzle outlet,the influence law of air pressure and voltage on liquid film thickness(h)and transverse and longitudinal fluctuations are ***,the mathematical model of charged droplet volume average diameter(VAD)is constructed based on three dimensions of the liquid film,namely its thickness,transverse wavelength(λ_(h)),and longitudinal wavelength(λ_(z)).The model results under different working conditions are obtained by numerical *** of the model results with the experimental VAD of the droplet confirm the error of the mathematical model to be less than 10%.The droplet diameter distribution span value Rosin–Rammler distribution span(R.S)and percentage concentrations of PM10(particle size of less than 10μm)/PM2.5(particle size of less than 2.5μm)under different working conditions are further *** results show that electrostatic atomization not only reduces the diameter distribution span of atomized droplets but also significantly inhibits the formation of PM10 and PM2.5 fine-suspension *** the air pressure is 0.3 MPa,and the voltage is 40 kV,the percentage concentrations of PM10 and PM2.5 can be reduced by 80.72%and 92.05%,respectively,compared with that under the pure pneumatic atomization condition at 0.3 MPa.

关键词： minimum quantity lubrication(MQL) electrostatic atomization volume average diameter(VAD) atomization characteristics

Machinability of ultrasonic vibration-assisted micro-grinding in biological bone using nanolubricant

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Frontiers of Mechanical Engineering 2023年第1期18卷 115-130页

作者： Yuying YANG Min YANG Changhe LI Runze LI zafar SAID Hafiz Muhammad ALI Shubham SHARMA School of Mechanical and Automotive Engineering Qingdao University of TechnologyQingdao 266520China College of Physics Qingdao UniversityQingdao 266071China Department of Biomedical Engineering University of Southern CaliforniaLos AngelesCA 90089USA Department of Sustainable and Renewable Energy Engineering University of SharjahSharjah 27272United Arab Emirates Mechanical Engineering Department King Fahd University of Petroleum and MineralsDhahran 31261Saudi Arabia Department of Mechanical Engineering IK Gujral Punjab Technical UniversityJalandhar 144603India

Bone grinding is an essential and vital procedure in most surgical ***,the insufficient cooling capacity of dry grinding,poor visibility of drip irrigation surgery area,and large grinding force leading to high grinding temperature are the technical bottlenecks of micro-grinding.A new micro-grinding process called ultrasonic vibration-assisted nanoparticle jet mist cooling(U-NJMC)is innovatively proposed to solve the technical *** combines the advantages of ultrasonic vibration(UV)and nanoparticle jet mist cooling(NJMC).Notwithstanding,the combined effect of multi parameter collaborative of U-NJMC on cooling has not been *** grinding force,friction coefficient,specific grinding energy,and grinding temperature under dry,drip irrigation,UV,minimum quantity lubrication(MQL),NJMC,and U-NJMC micro-grinding were compared and *** showed that the minimum normal grinding force and tangential grinding force of U-NJMC micro-grinding were 1.39 and 0.32 N,which were 75.1%and 82.9%less than those in dry grinding,*** minimum friction coefficient and specific grinding energy were achieved using *** with dry,drip,UV,MQL,and NJMC grinding,the friction coefficient of U-NJMC was decreased by 31.3%,17.0%,19.0%,9.8%,and 12.5%,respectively,and the specific grinding energy was decreased by 83.0%,72.7%,77.8%,52.3%,and 64.7%,*** with UV or NJMC alone,the grinding temperature of U-NJMC was decreased by 33.5%and 10.0%,*** results showed that U-NJMC provides a novel approach for clinical surgical micro-grinding of biological bone.

关键词： micro-grinding biological bone ultrasonic vibration(UV) nanoparticle jet mist cooling(NJMC) grinding force grinding temperature

Intense supercontinuum generation in the near-ultraviolet range from a 400-nm femtosecond laser filament array in fused silica

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Chinese Physics B 2017年第7期26卷 149-152页

作者：李东伟张兰芝 Saba zafar 宋鹤郝作强奚婷婷高勋林景全 School of Science Changchun University of Science and Technology School of Physics University of Chinese Academy of Sciences

An intense supercontinuum（SC） in the near-ultraviolet range is generated from filamentation by focusing a 400-nm laser into fused silica with a microlens array（MLA）. The spectrum of the SC is shown to be sensitive to the distance between the MLA and fused silica. In our optimal conditions, the near-ultraviolet SC can cover a range of 350-600 nm,where a bandwidth of approximately 55 nm above the 1μJ/nm spectral energy density and 20 nm bandwidth with tens ofμJ/nm are achieved. In addition, the energy conversion efficiency of the 400 nm laser for SC generation is further analyzed.A maximum conversion efficiency of 66% is obtained when the entrance face of fused silica is set around the focus of the MLA.

关键词： filamentation supercontinuum generation microlens array fused silica

Heavy atom-free triplet photosensitizer based on thermally activated delayed fluorescence material for NIR-to-blue triplet-triplet annihilation upconversion

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Chinese Chemical Letters 2023年第2期34卷 403-406页

作者： Hui Liang Xiaoyu Liu Liting Tang zafar Mahmood Zeduan Chen Guowei Chen Shaomin Ji Yanping Huo School of Chemical Engineering and Light Industry Guangdong University of TechnologyGuangzhou 510006China

Triplet-triplet annihilation(TTA) upconversion-based materials have potential application in the broad range of research areas, including photocatalysis and life sciences. However, near-infrared(NIR)-to-blue upconverted emission is preferred for most of the practical applications, but developing a NIR-to-blue TTA upconversion system is a challenging task in photochemistry. In this work, a thermally activated delayed fluorescence(TADF) material with intense visible-to-NIR absorption is demonstrated that shows a longer triplet state lifetime(32 μs) and high triplet state energy(E_(T)= 1.55 e V). For the first time, a heavy atomfree NIR(λ_(ex)> 650 nm) to blue(λ_(em)< 460 nm) TTA upconversion system was devised, employing the dimeric borondifluoride curcuminoid TADF material as triplet photosensitizer(PS) and a large anti-Stokes shift(0.88 e V) along with moderate upconversion yield was achieved. Our work provides the solution and guidance for the future development of purely organic heavy atom-free NIR activating TTA upconversion system for a wide array of applications.

关键词： Heavy atom-free Triplet state Photosensitizer TTA-upconversion

Mechanical behavior and semiempirical force model of aerospace aluminum alloy milling using nano biological lubricant

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Frontiers of Mechanical Engineering 2023年第1期18卷 55-69页

作者： Zhenjing DUAN Changhe LI Yanbin ZHANG Min YANG Teng GAO Xin LIU Runze LI zafar SAID Sujan DEBNATH Shubham SHARMA School of Mechanical and Automotive Engineering Qingdao University of TechnologyQingdao 266520China School of Mechanical Engineering Dalian University of TechnologyDalian 116024China State Key Laboratory of Ultra-precision Machining Technology Department of Industrial and Systems EngineeringThe Hong Kong Polytechnic UniversityHong Kong 999077China Department of Biomedical Engineering University of Southern CaliforniaLos AngelesCA 90089-1111USA College of Engineering University of SharjahSharjah 27272United Arab Emirates Mechanical Engineering Department Curtin UniversityMiri 98009Malaysia Department of Mechanical Engineering IK Gujral Punjab Technical UniversityPunjab 144603India

Aerospace aluminum alloy is the most used structural material for rockets,aircraft,spacecraft,and space *** deterioration of surface integrity of dry machining and the insufficient heat transfer capacity of minimal quantity lubrication have become the bottleneck of lubrication and heat dissipation of aerospace aluminum ***,the excellent thermal conductivity and tribological properties of nanofluids are expected to fill this *** traditional milling force models are mainly based on empirical models and finite element simulations,which are insufficient to guide industrial *** this study,the milling force of the integral end milling cutter is deduced by force analysis of the milling cutter element and numerical *** instantaneous milling force model of the integral end milling cutter is established under the condition of dry and nanofluid minimal quantity lubrication(NMQL)based on the dual mechanism of the shear effect on the rake face of the milling cutter and the plow cutting effect on the flank surface.A single factor experiment is designed to introduce NMQL and the milling feed factor into the instantaneous milling force *** average absolute errors in the prediction of milling forces for the NMQL are 13.3%,2.3%,and 7.6%in the x-,y-,and z-direction,*** with the milling forces obtained by dry milling,those by NMQL decrease by 21.4%,17.7%,and 18.5%in the x-,y-,and z-direction,respectively.

关键词： milling force nanofluid minimum quantity lubrication aerospace aluminum alloy nano biological lubricant

Comparative assessment of force,temperature,and wheel wear in sustainable grinding aerospace alloy using biolubricant

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Frontiers of Mechanical Engineering 2023年第1期18卷 1-33页

作者： Xin CUI Changhe LI Yanbin ZHANG Wenfeng DING Qinglong AN Bo LIU Hao Nan LI zafar SAID Shubham SHARMA Runze LI Sujan DEBNATH School of Mechanical and Automotive Engineering Qingdao University of TechnologyQingdao 266520China State Key Laboratory of Ultra-precision Machining Technology Department of Industrial and Systems EngineeringThe Hong Kong Polytechnic UniversityHong KongChina College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China Sichuan Future Aerospace Industry LLC. Shifang 618400China School of Aerospace University of Nottingham Ningbo ChinaNingbo 315100China College of Engineering University of SharjahSharjah 27272United Arab Emirates Department of Mechanical Engineering IK Gujral Punjab Technical UniversityPunjab 144603India Department of Biomedical Engineering University of Southern CaliforniaLos AngelesCA 90089USA Mechanical Engineering Department Curtin UniversityMiri 98009Malaysia

The substitution of biolubricant for mineral cutting fluids in aerospace material grinding is an inevitable development direction,under the requirements of the worldwide carbon emission ***,serious tool wear and workpiece damage in difficult-to-machine material grinding challenges the availability of using biolubricants via minimum quantity *** primary cause for this condition is the unknown and complex influencing mechanisms of the biolubricant physicochemical properties on *** this review,a comparative assessment of grindability is performed using titanium alloy,nickel-based alloy,and high-strength ***,this work considers the physicochemical properties as the main factors,and the antifriction and heat dissipation behaviours of biolubricant in a high temperature and pressure interface are comprehensively ***,the comparative assessment of force,temperature,wheel wear and workpiece surface for titanium alloy,nickel-based alloy,and high-strength steel confirms that biolubricant is a potential replacement of traditional cutting fluids because of its improved lubrication and cooling ***-viscosity biolubricant and nano-enhancers with high thermal conductivity are recommended for titanium alloy to solve the burn puzzle of the *** with high viscosity and high fatty acid saturation characteristics should be used to overcome the bottleneck of wheel wear and nickel-based alloy surface *** nano-enhancers with high hardness and spherical characteristics are better ***,a different option is available for high-strength steel grinding,which needs low-viscosity biolubricant to address the debris breaking difficulty and wheel ***,the current challenges and potential methods are proposed to promote the application of biolubricant.

关键词： grinding aerospace difficult-to-machine material biolubricant physicochemical property grindability

Vegetable Oil-Based Nanolubricants in Machining:From Physicochemical Properties to Application

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Chinese Journal of Mechanical Engineering 2023年第4期36卷 4-42页

作者： Xiaotian Zhang Changhe Li Zongming Zhou Bo Liu Yanbin Zhang Min Yang Teng Gao Mingzheng Liu Naiqing Zhang zafar Said Shubham Sharma Hafiz Muhammad Ali School of Mechanical and Automotive Engineering Qingdao University of TechnologyQingdao 266520China Hanergy(Qingdao)Lubrication Technology Co. Ltd.Qingdao 266200China 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 Department of Mechanical Engineering and Advanced Materials Science Regional Center for Extension and DevelopmentCouncil of Scientific and Industrial Research(CSIR)-Central Leather Research Institute(CLRI)Jalandhar 144021India Mechanical Engineering Department King Fahd University of Petroleum and MineralsDhahran 31261Saudi Arabia

Cutting fluid is crucial in ensuring surface quality and machining accuracy during ***,traditional mineral oil-based cutting fluids no longer meet modern machining’s health and environmental protection *** a renewable,pollution-free alternative with excellent processing characteristics,vegetable oil has become an inevitable ***,vegetable oil lacks oxidation stability,extreme pressure,and antiwear proper-ties,which are essential for machining *** physicochemical characteristics of vegetable oils and the improved methods’application mechanism are not fully *** study aims to investigate the effects of viscosity,surface tension,and molecular structure of vegetable oil on cooling and lubricating *** mechanisms of autoxidation and high-temperature oxidation based on the molecular structure of vegetable oil are also *** study further investigates the application mechanism and performance of chemical modification and antioxidant *** study shows that the propionic ester of methyl hydroxy-oleate obtained by epoxidation has an initial oxidation temperature of 175℃.The application mechanism and extreme pressure performance of conventional extreme pressure additives and nanoparticle additives were also investigated to solve the problem of insufficient oxidation resistance and extreme pressure performance of nanobiological ***,the study discusses the future prospects of vegetable oil for chemical modification and nanoparticle *** study provides theoretical guidance and technical support for the industrial application and scientific research of vegetable oil in the field of lubrication and *** is expected to promote sustainable development in the manufacturing industry.

关键词： Cutting fluid Vegetable oil Chemical modification Antioxidant Extreme pressure additive Minimum quality lubrication