Substantially lightweight brake discs with high wear resistance are highly desirable in the automotive industry.This paper presents an investigation of the precision-engineering design and development of automotive br...Substantially lightweight brake discs with high wear resistance are highly desirable in the automotive industry.This paper presents an investigation of the precision-engineering design and development of automotive brake discs using nonhomogeneous Al/SiC metal-matrixcomposite materials.The design and development are based on modeling and analysis following stringent precision-engineering principles,i.e.,brake-disc systems that operate repeatably and stably over time as enabled by precision-engineering design.The design and development are further supported by tribological experimental testing and finite-element simulations.The results show the industrial feasibility of the innovative design approach and the application merits of using advanced metal-matrix-composite materials for next-generation automotive and electric vehicles.展开更多
http://www.keaipublishing.com/en/journals/nanotechnology-and-precision-engineering/Nanotechnology and Precision Engineering (NPE) is a peer-reviewed, interdisciplinary research journal that covers all areas related to...http://www.keaipublishing.com/en/journals/nanotechnology-and-precision-engineering/Nanotechnology and Precision Engineering (NPE) is a peer-reviewed, interdisciplinary research journal that covers all areas related to nanotechnology and precision engineering, which provides a forum for researchers of the related fi eld all over the world.展开更多
Expanding the specific surface area of substrates and carrying out precise surface engineering of imprinted nanocavities are crucial methods for enhancing the identification efficiency of molecularly imprinted polymer...Expanding the specific surface area of substrates and carrying out precise surface engineering of imprinted nanocavities are crucial methods for enhancing the identification efficiency of molecularly imprinted polymers(MIPs).To implement this synergistic strategy,bioinspired surface engineering was used to incorporate dual covalent receptors via precise post-imprinting modifications(PIMs)onto mesoporous silica nanosheets.The prepared sorbents(denoted as‘‘D-PMIPs”)were utilized to improve the specific identification of adenosine 5-monophosphate(AMP).Significantly,the mesoporous silica nanosheets possess a high surface area of approximately 498.73 m^(2)·g^(-1),which facilitates the formation of abundant specific recognition sites in the D-PMIPs.The dual covalent receptors are valuable for estab-lishing the spatial orientation and arrangement of AMP through multiple cooperative interactions.PIMs enable precise site-specific functionalization within the imprinted cavities,leading to the tailor-made formation of complementary binding sites.The maximum number of high-affinity binding sites(Nmax)of the D-PMIPs is 39.99 lmol·g^(-1),which is significantly higher than that of imprinted sorbents with a sin-gle receptor(i.e.,S-BMIPs or S-PMIPs).The kinetic data of the D-PMIPs can be effectively described by a pseudo-second-order model,indicating that the main binding mechanism involves synergistic chemisorption from boronate affinity and the pyrimidine base.This study suggests that using dual cova-lent receptors and PIMs is a reliable approach for creating imprinted sorbents with high selectivity,allow-ing for the controlled engineering of imprinted sites.展开更多
Metal superhydrophobic surfaces with anisotropic wettability and adhesion have become more and more important due to their promising applications. Herein, we report a new fabrication strategy through a combination of ...Metal superhydrophobic surfaces with anisotropic wettability and adhesion have become more and more important due to their promising applications. Herein, we report a new fabrication strategy through a combination of pulsed laser ablation and low-temperature annealing post-processing. An inclined cone structure array is made on stainless steel surfaces, and then 120 °C low-temperature annealing is applied. Such surface displays excellent mechanical durability and anisotropic superhydrophobicity. It is demonstrated experimentally that the contact angle of water droplets on the surface is different along the parallel(167° ±2°) and perpendicular directions(157° ±2°) of the inclined cone structure. The sliding behaviors of water droplets and mechanical durability of the inclined cone structures are studied. These surfaces obtained in a short time with environmentally friendly fabrication can be applied in industries for water harvesting, droplet manipulation, and pipeline transportation.展开更多
A new type of air bearing with flexure structure is introduced. The new bearing is designed for precision mechanical engineering devices such as mechanical watch movement. The new design uses the flexure structure to ...A new type of air bearing with flexure structure is introduced. The new bearing is designed for precision mechanical engineering devices such as mechanical watch movement. The new design uses the flexure structure to provide 3D damping to absorb shocks from all directions. Two designs are presented： one has 12 T-shape slots in the radian direction while the other has 8 spiral slots in the radian direction. Both designs have flexure mountings on the axial directions. Based on the finite element analysis （FEA）, the new bearing can reduce the vibration （displacement） by as much as 8.37% and hence, can better protect the shafts.展开更多
Past 25 y have witnessed an exponential increase in knowledge and understanding of ocular diseases and their respective genetic underpinnings. As a result, scientists have mapped many genes and their variants that can...Past 25 y have witnessed an exponential increase in knowledge and understanding of ocular diseases and their respective genetic underpinnings. As a result, scientists have mapped many genes and their variants that can influence vision and health of our eyes. Based on these findings, it is becoming clear that an early diagnosis employing genetic testing can help evaluate patients＇ conditions for instituting treatment plan（s） and follow-up care to avoid vision complications later. For example, knowing family history becomes crucial for inherited eye diseases as it can benefit members in family who may have similar eye diseases or predispositions. Therefore, gathering information from an elaborate examination along with complete assessment of past medical illness by ophthalmologists followed by consultation with geneticists can help create a roadmap for making diagnosis and treatment precise and beneficial. In this review, we present an update on ocular genomic medicine that we believe has tremendous potential towards unraveling genetic implications in ocular diseases and patients＇ susceptibilities. We also discuss translational aspects of genetic ophthalmology and genome engineering that may help advance molecular diagnostics and therapeutics.展开更多
CONSPECTUS:Nanozymes are nanomaterials with intrinsic enzyme-like properties that can overcome the current limitations of natural enzymes,such as high preparation cost,instability,restricted application scenarios,etc....CONSPECTUS:Nanozymes are nanomaterials with intrinsic enzyme-like properties that can overcome the current limitations of natural enzymes,such as high preparation cost,instability,restricted application scenarios,etc.Since the Fe3O4 nanoparticles(NPs)were shown to possess the peroxidase(POD)-like activity in 2007,thousands of nanomaterials were reported to mimic the catalytic properties of various types of enzymes including catalase(CAT),haloperoxidase,superoxide dismutase(SOD),glucose oxidase,glutathione peroxidase,hydrolase,nuclease,nitroreductase,and others.展开更多
Precise chromosome engineering has traditionally relied on the Cre-Lox recombination system-an approach in which the enzyme Cre functions like molecular scissors,cutting and rejoining DNA at specific“Lox”sites to ad...Precise chromosome engineering has traditionally relied on the Cre-Lox recombination system-an approach in which the enzyme Cre functions like molecular scissors,cutting and rejoining DNA at specific“Lox”sites to add,remove,or flip genomic DNA segments inside living cells.展开更多
This paper introduces a non-assembly manufacturing case with microstereolithography technology. The design and manufacturing process of a pneumatic thrust bearing is described, and a special tessellation method is dev...This paper introduces a non-assembly manufacturing case with microstereolithography technology. The design and manufacturing process of a pneumatic thrust bearing is described, and a special tessellation method is developed to further improve the capability of the manufacturing system thus bigger products can also be easily manufactured. Implemented in a layer-by-layer fashion, stereolithography has been used for the rapid manufacturing of complex devices, and it avoids the expensive assembly process in the traditional manufacturing. This paper presents that microstereolithography can produce high-resolution products with intricate details, small openings, and smooth surfaces. The potential of the microstereolithograhy technique is explored for the rapid manufacturing of small and complex objects.展开更多
Atmospheric pressure plasma polishing （APPP） high quMity optical surfaces. The changes of is a precision machining technology used for manufacturing surface modulus and hardness after machining prove the distinct im...Atmospheric pressure plasma polishing （APPP） high quMity optical surfaces. The changes of is a precision machining technology used for manufacturing surface modulus and hardness after machining prove the distinct improvement of surface mechanical properties. The demonstrated decrease of surface residual stresses testifies the removal of the former deformation layer. And the surface topographies under atomic force microscope （AFM） and scanning electron microscope （SEM） indicate obvious amelioration of the surface status, showing that the 0.926-nm average surface roughness has been achieved.展开更多
An aided Inertial Navigation System(INS)is increasingly exploited in precise engineering surveying,such as railway track irregularity measurement,where a high relative measurement accuracy rather than absolute accurac...An aided Inertial Navigation System(INS)is increasingly exploited in precise engineering surveying,such as railway track irregularity measurement,where a high relative measurement accuracy rather than absolute accuracy is emphasized.However,how to evaluate the relative measurement accuracy of the aided INS has rarely been studied.We address this problem with a semi-analytical method to analyze the relative measurement error propagation of the Global Navigation Satellite System(GNSS)and INS integrated system,specifically for the railway track irregularity measurement application.The GNSS/INS integration in this application is simplified as a linear time-invariant stochastic system driven only by white Gaussian noise,and an analytical solution for the navigation errors in the Laplace domain is obtained by analyzing the resulting steady-state Kalman filter.Then,a time series of the error is obtained through a subsequent Monte Carlo simulation based on the derived error propagation model.The proposed analysis method is then validated through data simulation and field tests.The results indicate that a 1 mm accuracy in measuring the track irregularity is achievable for the GNSS/INS integrated system.Meanwhile,the influences of the dominant inertial sensor errors on the final measurement accuracy are analyzed quantitatively and discussed comprehensively.展开更多
The effective utilization of solar energy for hydrogen production requires an abundant supply of thermodynamically active photo-electrons;however,the photocatalysts are generally impeded by insufficient light absorpti...The effective utilization of solar energy for hydrogen production requires an abundant supply of thermodynamically active photo-electrons;however,the photocatalysts are generally impeded by insufficient light absorption and fast photocarrier recombination.Here,we report a multiple-regulated strategy to capture photons and boost photocarrier dynamics by devel-oping a broadband photocatalyst composed of defect engineered g-C_(3)N_(4)(DCN)and upconversion NaYF4:Yb^(3+),Tm^(3+)(NYF)nanocrystals.Through a precise defect engineering,the S dopants and C vacancies jointly render DCN with defect states to effectively extend the visible light absorption to 590 nm and boost photocarrier separation via a moderate electron-trapping ability,thus facilitating the subsequent re-absorption and utilization of upconverted photons/electrons.Importantly,we found a promoted interfacial charge polarization between DCN and NYF has also been achieved mainly due to Y-N interaction,which further favors the upconverted excited energy transfer from NYF onto DCN as verified both theoretically and experimentally.With a 3D architecture,the NYF@DCN catalyst exhibits a superior solar H2 evolution rate among the reported upconversion-based system,which is 19.3 and 1.5 fold higher than bulk material and DCN,respectively.This work provides an innovative strategy to boost solar utilization by using defect engineering and building up interaction between hetero-materials.展开更多
Developing approaches for precise engineering of the optical response of plasmonic nanocavities at the postfabrication stage is important for achieving enhanced and tunable light-matter interactions.In this work,we de...Developing approaches for precise engineering of the optical response of plasmonic nanocavities at the postfabrication stage is important for achieving enhanced and tunable light-matter interactions.In this work,we demonstrate selective enhancement/suppression of specific plasmonic modes by embedding nanocube-on-mirror plasmonic nanocavities into a poly(methyl methacrylate)(PMMA)layer with a controllable thickness.With the increase of the PMMA thickness from 0 to approximately 100 nm,the dominating out-of-plane plasmonic modes are significantly suppressed in the scattering spectra,while the in-plane plasmonic modes are greatly enhanced with a factor reaching 102±20.This enhancement is related to the variation of momentum matching between the plasmonic modes and the radiative fields,affecting both mode excitation and emission properties.In addition,the spectral positions of the in-plane and out-of-plane plasmonic modes shift up to 52±5 and 81±2 nm,respectively.These properties are important for matching and enhancing plasmonic and molecular resonances in a variety of applications.展开更多
文摘Substantially lightweight brake discs with high wear resistance are highly desirable in the automotive industry.This paper presents an investigation of the precision-engineering design and development of automotive brake discs using nonhomogeneous Al/SiC metal-matrixcomposite materials.The design and development are based on modeling and analysis following stringent precision-engineering principles,i.e.,brake-disc systems that operate repeatably and stably over time as enabled by precision-engineering design.The design and development are further supported by tribological experimental testing and finite-element simulations.The results show the industrial feasibility of the innovative design approach and the application merits of using advanced metal-matrix-composite materials for next-generation automotive and electric vehicles.
文摘http://www.keaipublishing.com/en/journals/nanotechnology-and-precision-engineering/Nanotechnology and Precision Engineering (NPE) is a peer-reviewed, interdisciplinary research journal that covers all areas related to nanotechnology and precision engineering, which provides a forum for researchers of the related fi eld all over the world.
基金supported by the National Natural Science Foundation of China(22078132,22108103,and U22A20413)the Open Funding Project of the National Key Labora-tory of Biochemical Engineering(2021KF-02)+3 种基金China Postdoctoral Science Foundation(2021M691301)Jiangsu Key Research and Development Program(BE2022356)the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation(CPSF)(GZ20230989)Jiangsu Agricultural Independent Innovation Fund Project(CX(21)3079).
文摘Expanding the specific surface area of substrates and carrying out precise surface engineering of imprinted nanocavities are crucial methods for enhancing the identification efficiency of molecularly imprinted polymers(MIPs).To implement this synergistic strategy,bioinspired surface engineering was used to incorporate dual covalent receptors via precise post-imprinting modifications(PIMs)onto mesoporous silica nanosheets.The prepared sorbents(denoted as‘‘D-PMIPs”)were utilized to improve the specific identification of adenosine 5-monophosphate(AMP).Significantly,the mesoporous silica nanosheets possess a high surface area of approximately 498.73 m^(2)·g^(-1),which facilitates the formation of abundant specific recognition sites in the D-PMIPs.The dual covalent receptors are valuable for estab-lishing the spatial orientation and arrangement of AMP through multiple cooperative interactions.PIMs enable precise site-specific functionalization within the imprinted cavities,leading to the tailor-made formation of complementary binding sites.The maximum number of high-affinity binding sites(Nmax)of the D-PMIPs is 39.99 lmol·g^(-1),which is significantly higher than that of imprinted sorbents with a sin-gle receptor(i.e.,S-BMIPs or S-PMIPs).The kinetic data of the D-PMIPs can be effectively described by a pseudo-second-order model,indicating that the main binding mechanism involves synergistic chemisorption from boronate affinity and the pyrimidine base.This study suggests that using dual cova-lent receptors and PIMs is a reliable approach for creating imprinted sorbents with high selectivity,allow-ing for the controlled engineering of imprinted sites.
基金Project(A19C2a0019) supported by the Advanced Remanufacturing and Technology Centre (ARTC) under its RIE2020 Advanced Manufacturing and Engineering (AME) IAF PP,Singapore。
文摘Metal superhydrophobic surfaces with anisotropic wettability and adhesion have become more and more important due to their promising applications. Herein, we report a new fabrication strategy through a combination of pulsed laser ablation and low-temperature annealing post-processing. An inclined cone structure array is made on stainless steel surfaces, and then 120 °C low-temperature annealing is applied. Such surface displays excellent mechanical durability and anisotropic superhydrophobicity. It is demonstrated experimentally that the contact angle of water droplets on the surface is different along the parallel(167° ±2°) and perpendicular directions(157° ±2°) of the inclined cone structure. The sliding behaviors of water droplets and mechanical durability of the inclined cone structures are studied. These surfaces obtained in a short time with environmentally friendly fabrication can be applied in industries for water harvesting, droplet manipulation, and pipeline transportation.
基金Selected from Proceedings of the 7th International Conference on Frontiers of DesignManufacturing(ICFDM'2006)This project is partially sup-ported by the Research Grant from the Hong Kong Watch Manufacturers Association the Federation of Hong Kong Watch TradeIndustry Technology Commission China(No.ITS/001/05).
文摘A new type of air bearing with flexure structure is introduced. The new bearing is designed for precision mechanical engineering devices such as mechanical watch movement. The new design uses the flexure structure to provide 3D damping to absorb shocks from all directions. Two designs are presented： one has 12 T-shape slots in the radian direction while the other has 8 spiral slots in the radian direction. Both designs have flexure mountings on the axial directions. Based on the finite element analysis （FEA）, the new bearing can reduce the vibration （displacement） by as much as 8.37% and hence, can better protect the shafts.
基金Supported in part by NIH Heart,Lung,and Blood Institute(No.HLO74815)Institute of Neurological Disorders and Stroke(No.NS-084823)
文摘Past 25 y have witnessed an exponential increase in knowledge and understanding of ocular diseases and their respective genetic underpinnings. As a result, scientists have mapped many genes and their variants that can influence vision and health of our eyes. Based on these findings, it is becoming clear that an early diagnosis employing genetic testing can help evaluate patients＇ conditions for instituting treatment plan（s） and follow-up care to avoid vision complications later. For example, knowing family history becomes crucial for inherited eye diseases as it can benefit members in family who may have similar eye diseases or predispositions. Therefore, gathering information from an elaborate examination along with complete assessment of past medical illness by ophthalmologists followed by consultation with geneticists can help create a roadmap for making diagnosis and treatment precise and beneficial. In this review, we present an update on ocular genomic medicine that we believe has tremendous potential towards unraveling genetic implications in ocular diseases and patients＇ susceptibilities. We also discuss translational aspects of genetic ophthalmology and genome engineering that may help advance molecular diagnostics and therapeutics.
基金supported by the National Key R&D Program of China(No.2022YFA1205801)the National Natural Science Foundation of China(Nos.T2225026,82172087,52202344,82071308)the Beijing Institute of Technology Research Fund Program for Young Scholars.
文摘CONSPECTUS:Nanozymes are nanomaterials with intrinsic enzyme-like properties that can overcome the current limitations of natural enzymes,such as high preparation cost,instability,restricted application scenarios,etc.Since the Fe3O4 nanoparticles(NPs)were shown to possess the peroxidase(POD)-like activity in 2007,thousands of nanomaterials were reported to mimic the catalytic properties of various types of enzymes including catalase(CAT),haloperoxidase,superoxide dismutase(SOD),glucose oxidase,glutathione peroxidase,hydrolase,nuclease,nitroreductase,and others.
文摘Precise chromosome engineering has traditionally relied on the Cre-Lox recombination system-an approach in which the enzyme Cre functions like molecular scissors,cutting and rejoining DNA at specific“Lox”sites to add,remove,or flip genomic DNA segments inside living cells.
基金financially supported by National Natural Science Foundation of China(22172077,T2322013)the Scientific Research Foundation of Chemistry and Chemical Engineering Guangdong Laboratory(2011001)the support by the National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICT(2018M3D1A1058624,2019R1A2C3010479)。
基金Supported by Centre of Excellence in Customized Assembly(CECA)
文摘This paper introduces a non-assembly manufacturing case with microstereolithography technology. The design and manufacturing process of a pneumatic thrust bearing is described, and a special tessellation method is developed to further improve the capability of the manufacturing system thus bigger products can also be easily manufactured. Implemented in a layer-by-layer fashion, stereolithography has been used for the rapid manufacturing of complex devices, and it avoids the expensive assembly process in the traditional manufacturing. This paper presents that microstereolithography can produce high-resolution products with intricate details, small openings, and smooth surfaces. The potential of the microstereolithograhy technique is explored for the rapid manufacturing of small and complex objects.
基金supported by the National Natural Science Foundation of China (Nos.50535020 and 50775055)the Defense Advanced Research Foundation (No.9140A180202-06HT0132)the Natural Science Foundation of Heilongjiang Province (No.E200622)
文摘Atmospheric pressure plasma polishing （APPP） high quMity optical surfaces. The changes of is a precision machining technology used for manufacturing surface modulus and hardness after machining prove the distinct improvement of surface mechanical properties. The demonstrated decrease of surface residual stresses testifies the removal of the former deformation layer. And the surface topographies under atomic force microscope （AFM） and scanning electron microscope （SEM） indicate obvious amelioration of the surface status, showing that the 0.926-nm average surface roughness has been achieved.
基金the National Natural Science Foundation of China(41904019).
文摘An aided Inertial Navigation System(INS)is increasingly exploited in precise engineering surveying,such as railway track irregularity measurement,where a high relative measurement accuracy rather than absolute accuracy is emphasized.However,how to evaluate the relative measurement accuracy of the aided INS has rarely been studied.We address this problem with a semi-analytical method to analyze the relative measurement error propagation of the Global Navigation Satellite System(GNSS)and INS integrated system,specifically for the railway track irregularity measurement application.The GNSS/INS integration in this application is simplified as a linear time-invariant stochastic system driven only by white Gaussian noise,and an analytical solution for the navigation errors in the Laplace domain is obtained by analyzing the resulting steady-state Kalman filter.Then,a time series of the error is obtained through a subsequent Monte Carlo simulation based on the derived error propagation model.The proposed analysis method is then validated through data simulation and field tests.The results indicate that a 1 mm accuracy in measuring the track irregularity is achievable for the GNSS/INS integrated system.Meanwhile,the influences of the dominant inertial sensor errors on the final measurement accuracy are analyzed quantitatively and discussed comprehensively.
基金support provided by the ARC through the ARC DP200101249 project.J.Feng would like to thank the computational resources provided by the High-Performance Computing Center of Qufu Normal University.D.Wang would like to acknowledge the National Natural Science Foundation of China(21903048,21971244,51932001,21931012,21590795)and National Key R&D Program of China(2018YFA0703504,2021YFB3802600).
文摘The effective utilization of solar energy for hydrogen production requires an abundant supply of thermodynamically active photo-electrons;however,the photocatalysts are generally impeded by insufficient light absorption and fast photocarrier recombination.Here,we report a multiple-regulated strategy to capture photons and boost photocarrier dynamics by devel-oping a broadband photocatalyst composed of defect engineered g-C_(3)N_(4)(DCN)and upconversion NaYF4:Yb^(3+),Tm^(3+)(NYF)nanocrystals.Through a precise defect engineering,the S dopants and C vacancies jointly render DCN with defect states to effectively extend the visible light absorption to 590 nm and boost photocarrier separation via a moderate electron-trapping ability,thus facilitating the subsequent re-absorption and utilization of upconverted photons/electrons.Importantly,we found a promoted interfacial charge polarization between DCN and NYF has also been achieved mainly due to Y-N interaction,which further favors the upconverted excited energy transfer from NYF onto DCN as verified both theoretically and experimentally.With a 3D architecture,the NYF@DCN catalyst exhibits a superior solar H2 evolution rate among the reported upconversion-based system,which is 19.3 and 1.5 fold higher than bulk material and DCN,respectively.This work provides an innovative strategy to boost solar utilization by using defect engineering and building up interaction between hetero-materials.
基金National Key Research and Development Program of China(2023YFB2806701)National Natural Science Foundation of China(92250305,62305293)+2 种基金Natural Science Foundation of Zhejiang Province(LR25F050001,LDT23F04015F05)Engineering and Physical Sciences Research Council(EP/W017075/1)New Cornerstone Science Foundation(NCI202216)。
文摘Developing approaches for precise engineering of the optical response of plasmonic nanocavities at the postfabrication stage is important for achieving enhanced and tunable light-matter interactions.In this work,we demonstrate selective enhancement/suppression of specific plasmonic modes by embedding nanocube-on-mirror plasmonic nanocavities into a poly(methyl methacrylate)(PMMA)layer with a controllable thickness.With the increase of the PMMA thickness from 0 to approximately 100 nm,the dominating out-of-plane plasmonic modes are significantly suppressed in the scattering spectra,while the in-plane plasmonic modes are greatly enhanced with a factor reaching 102±20.This enhancement is related to the variation of momentum matching between the plasmonic modes and the radiative fields,affecting both mode excitation and emission properties.In addition,the spectral positions of the in-plane and out-of-plane plasmonic modes shift up to 52±5 and 81±2 nm,respectively.These properties are important for matching and enhancing plasmonic and molecular resonances in a variety of applications.
