Laser anti-drone technology is entering the sequence of actual combat,and it is necessary to consider the vulnerability of typical functional parts of UAVs.Since the concept of"vulnerability"was proposed,a v...Laser anti-drone technology is entering the sequence of actual combat,and it is necessary to consider the vulnerability of typical functional parts of UAVs.Since the concept of"vulnerability"was proposed,a variety of analysis programs for battlefield targets to traditional weapons have been developed,but a comprehensive assessment methodology for targets'vulnerability to laser is still missing.Based on the shotline method,this paper proposes a method that equates laser beam to shotline array,an efficient vulnerability analysis program of target to laser is established by this method,and the program includes the circuit board and the wire into the vulnerability analysis category,which improves the precision of the vulnerability analysis.Taking the UAV engine part as the target of vulnerability analysis,combine with the"life-death unit method"to calculate the laser penetration rate of various materials of the UAV,and the influence of laser weapon system parameters and striking orientation on the killing probability is quantified after introducing the penetration rate into the vulnerability analysis program.The quantitative analysis method proposed in this paper has certain general expansibility,which can provide a fresh idea for the vulnerability analysis of other targets to laser.展开更多
The mechanical properties,such as hardness and modulus of elasticity of coatings and the part of thin walls of Ni-based and Co-based alloy prepared by LENS were measured by nanoindentation testing,scanning electron mi...The mechanical properties,such as hardness and modulus of elasticity of coatings and the part of thin walls of Ni-based and Co-based alloy prepared by LENS were measured by nanoindentation testing,scanning electron microscopy and energy dispersive spectroscopy were used to analyze their microstructure,the affect of parameters on structure and mechanical properties were studied.The results showed that the mechanical properties were basically identical with the whole coating;the hardness and modulus of elasticity of nanoindentation were evenly distributed in the defect field.The average hardness and modulus of elasticity of coating of Ni-based alloy are 8.29GPa and 235GPa.The average hardness and modulus of elasticity of coating of Co-based alloy are 7.08GPa and 243GPa.The modulus of elasticity of part of thin walls has relationship with the grain orientation.展开更多
Laser engineered net shaping(LENS) process was investigated using Co-based superalloy powder with a high power continuous wave CO2 laser. Thin wall part with smooth surface was obtained by LENS of layer-by-layer depos...Laser engineered net shaping(LENS) process was investigated using Co-based superalloy powder with a high power continuous wave CO2 laser. Thin wall part with smooth surface was obtained by LENS of layer-by-layer deposition of the powder materials. This thin wall sample was tested for metallographic examinations, micro-hardness, X-ray diffraction and mechanical property test. Microstructural results show that the layers possess rapid solidification microstructural feature, fine dendritic crystal and M7C3-type carbides (essentially chromium-rich carbide) dispersed in theγ(Co,Cr) phase matrix. Dendrite spacing as well as the solidification mode can be controlled through control process parameters. In addition, this microstructural feature of the as-formed Co-base sample leads to an evident hardening and a superior tensile strength and toughness.展开更多
In this work,the evolution of melt pool under single-point and single-line printing in the laser engineered net shaping(LENS)process is analyzed.Firstly,the basic structure of the melt pool model of the LENS process i...In this work,the evolution of melt pool under single-point and single-line printing in the laser engineered net shaping(LENS)process is analyzed.Firstly,the basic structure of the melt pool model of the LENS process is established and the necessary assumptions are made.Then,the establishment process of the multi-physical field model of the melt pool is introduced in detail.It is concluded that the simulation model results are highly consistent with the online measurement experiment results in terms of melt pool profile,space temperature gradient,and time temperature gradient.Meanwhile,some parameters,such as the 3D morphology and surface fluid field of the melt pool,which are not obtained in the online measurement experiment,are analyzed.Finally,the influence of changing the scanning speed on the profile,peak temperature,and temperature gradient of the single-line melt pool is also analyzed,and the following conclusions are obtained:With the increase in scanning speed,the profile of the melt pool gradually becomes slender;The relationship between peak temperature and scanning speed is approximately linear in a certain speed range;The space temperature gradient at the tail of the melt pool under different scanning speeds hardly changes with the scanning speed,and the time temperature gradient at the tail of the melt pool is in direct proportion to the scanning speed.展开更多
The concepts of “confining structure” and structure light are illuminated in this paper.A laser theodolite with three freedoms of rotation,which is aimed at “confining structure”,is developed.Various scanning mode...The concepts of “confining structure” and structure light are illuminated in this paper.A laser theodolite with three freedoms of rotation,which is aimed at “confining structure”,is developed.Various scanning modes and their mathematical models based on laser theodolite with three freedoms of rotation are discussed.According to the features of a huge object,,the structure light engineering surveying based on laser theodolite with three freedoms of rotation is determined as the main method in an actual application.The observation of four sound concrete posts and forced centering plates.Subsequently,it is transformed into the huge object coordinate system.The scanning mode with plumb plane is selected as the main mode in the whole work.And other assistant methods,such as close range photogrammetry and the method of using reflection sheet,are applied to the work of “scanning dead angle”.At last,a surveying accuracy estimation of this method is done and a surveying accuracy test is finished.It can be concluded that the structure light engineering surveying based on laser theodolite with three freedoms of rotation is considered to be an effective and applied method,and has many superiority to some other surveying methods in the work of surveying “confining structure”.展开更多
Purpose: Selective laser sintering (SLS) is a rapid pro- totyping technique applied to produce tissue-engineer- ing scaffolds from powder materials. The standard scanning technique, however, often produces struts of e...Purpose: Selective laser sintering (SLS) is a rapid pro- totyping technique applied to produce tissue-engineer- ing scaffolds from powder materials. The standard scanning technique, however, often produces struts of extensive thickness, which means fabrication of high- ly porous scaffolds with small overall dimensions is quite difficult. Nevertheless, this study aims to overcome this shortfall. Design/methodology/approach: To this end, three scanning methods were evaluated in terms of minimum feature size and freedom of design, using a test polyamide (PA) material. Polycaprolactone (PCL) was then employed to create highly porous 3D scaffolds using the preferred scanning me- thod to produce thin struts. Findings: While in normal scanning mode some features were well above the laser spot diameter, strut thicknesses below the laser spot diameter were achieved when using the “outline scan” function for PA material. Those achieved for PCL were slightly higher and in the 500-800 ?m range, with an average pore size of 400 μm. Investigations on the properties of the scaffolds revealed an effective compression modulus of the PCL scaffold of 6.5 MPa. Furthermore, there was no change in physical or che- mical properties when the scaffolds were stored in a physiological environment for 7 weeks. Originality/ value: Though SLS is considered as a fabrication te- chnique for tissue engineering scaffolds, actually pro- duced scaffolds did not comply with porosity requirements and limitations of the SLS process in produ- cing features at the size of the laser beam spot have not been discussed. The present paper shows the capabilities of the SLS process based on two materials and presents a method to minimize feature size in scaffolds.展开更多
MALDI-TOF-MS technology was used for identification of lipopeptide antibiotics producedby GEB3 strain, a derivative of Bacillus subtilis 168 which was transformed by lpaB3gene. The result showed GEB3 only produced lip...MALDI-TOF-MS technology was used for identification of lipopeptide antibiotics producedby GEB3 strain, a derivative of Bacillus subtilis 168 which was transformed by lpaB3gene. The result showed GEB3 only produced lipopeptide antibiotic surfactin. The analysisby LC-MS demonstrated that GEB3 produced standard surfactin isoforms with side chainlengths of 13,14 and 15 carbon atoms. The bioactivity detection of surfactin indicatedthat the surfactin produced by GEB3 had inhibition effect on plant pathogens Rhizoctoniasolani and Pyricularia oryzae.展开更多
In this paper,a series of new techniques are used to optimize typical laser scanning sensor.The integrated prototype is compared with traditional approach to demonstrate the much improved performance.In the research a...In this paper,a series of new techniques are used to optimize typical laser scanning sensor.The integrated prototype is compared with traditional approach to demonstrate the much improved performance.In the research and development,camera calibration is achieved by extracting characteristic points of the laser plane,so that the calibra- tion efficiency is improved significantly.With feedback control of its intensity,the laser is automatically adjusted for different material.A modified algorithm is presented to improve the accuracy of laser stripe extraction.The fusion of data extracted from left and right camera is completed with re-sampling technique.The scanner is integrated with a robot arm and some other machinery for on-line measurement and inspection,which provides a flexible measurement tool for reverse engineering.展开更多
Integration of sensors with engineering thermoplastics allows to track their health and surrounding stimuli.As one of vital backbones to construct sensor systems,copper(Cu)is highly conductive and cost-effective,yet t...Integration of sensors with engineering thermoplastics allows to track their health and surrounding stimuli.As one of vital backbones to construct sensor systems,copper(Cu)is highly conductive and cost-effective,yet tends to easily oxidize during and after processing.Herein,an in-situ integrated sensor system on engineering thermoplastics via hybrid laser direct writing is proposed,which primarily consists of laser-passivated functional Cu interconnects and laser-induced carbon-based sensors.Through a one-step photothermal treatment,the resulting functional Cu interconnects after reductive sintering and passivation are capable of resisting long-term oxidation failure at high temperatures(up to 170℃)without additional encapsulations.Interfacing with signal processing units,such an all-in-one system is applied for long-term and real-time temperature monitoring.This integrated sensor system with facile laser manufacturing strategies holds potentials for health monitoring and fault diagnosis of advanced equipment such as aircrafts,automobiles,high-speed trains,and medical devices.展开更多
A PVA-GAG-COL composite scaffold is fabricated by polyvinyl alcohol （PVA）, glyeosaminoglycan （GAG） and collagen （COL）. Laser surface modification technology is used to make holes on the surface of the scaffolds....A PVA-GAG-COL composite scaffold is fabricated by polyvinyl alcohol （PVA）, glyeosaminoglycan （GAG） and collagen （COL）. Laser surface modification technology is used to make holes on the surface of the scaffolds. Inside and outside interconnection micro-porous structure is obtained. Bioeompatibility test of the scaffolds shows that PVA-GAG-COL scaffold can promote the adhesion and proliferation of the fibroblast. Also, fibroblast can grow normally on the scaffolds with pore diameter from 115 um to 255 um and pore distance from 500 um to 2000 um. PVA-GAG-COL scaffolds possess excellent cell biocompatibility. The porous structure is suitable for cell culture in tissue engineering.展开更多
Semiconductor-molecule surface-enhanced Raman scattering(SERS),especially the stronger interfacial charge transfer process(ICTP),represents a frontier in the field of SERS with spectral reproducibility and unparallele...Semiconductor-molecule surface-enhanced Raman scattering(SERS),especially the stronger interfacial charge transfer process(ICTP),represents a frontier in the field of SERS with spectral reproducibility and unparalleled selectivity.Herein,through a laser microfabrication method in situ,the free-standing,super hydrophilic and vacancy-rich TiO_(2-x)/Ti is successfully synthesized.Using blue TiO_(x)/Ti(B-TiO_(x)/Ti)as preconcentrated substrate,a nanomolar-level limit of detection of 12 nmol/L at 1385 cm–1,is confirmed using crystal violet(CV)bacteriostat as a model under 532 nm excitation.Furthermore,the results demonstrate that the SERS enhancement mechanism is via the moderate adulteration of oxygen vacancy,which leads to a narrow value of band gap and increases the ICTP of substrate to molecules.Using a hand-held extractor assembled with B-TiO_(x)/Ti microfiber,the operando analysis of mixtures distributed information excited in different parts of Asian carp is facilely achieved.This work guides the controlled synthesis of vacancy-rich TiO_(2-x)/Ti nanostructure and its application in ultrasensitive extraction-SERS detection.It also provides the direction for the rapid and operando transmission of biological information with temporal and spatial concentration distribution in human tissues by highly sensitized materials.展开更多
基金National Natural Science Foundation of China(Grant Nos.62005276,62175234)the Scientific and Technological Development Program of Jilin,China(Grant No.20230508111RC)to provide fund for this research。
文摘Laser anti-drone technology is entering the sequence of actual combat,and it is necessary to consider the vulnerability of typical functional parts of UAVs.Since the concept of"vulnerability"was proposed,a variety of analysis programs for battlefield targets to traditional weapons have been developed,but a comprehensive assessment methodology for targets'vulnerability to laser is still missing.Based on the shotline method,this paper proposes a method that equates laser beam to shotline array,an efficient vulnerability analysis program of target to laser is established by this method,and the program includes the circuit board and the wire into the vulnerability analysis category,which improves the precision of the vulnerability analysis.Taking the UAV engine part as the target of vulnerability analysis,combine with the"life-death unit method"to calculate the laser penetration rate of various materials of the UAV,and the influence of laser weapon system parameters and striking orientation on the killing probability is quantified after introducing the penetration rate into the vulnerability analysis program.The quantitative analysis method proposed in this paper has certain general expansibility,which can provide a fresh idea for the vulnerability analysis of other targets to laser.
基金supported by the National Key Laboratory Foundation(No.51461010101JB3501)
文摘The mechanical properties,such as hardness and modulus of elasticity of coatings and the part of thin walls of Ni-based and Co-based alloy prepared by LENS were measured by nanoindentation testing,scanning electron microscopy and energy dispersive spectroscopy were used to analyze their microstructure,the affect of parameters on structure and mechanical properties were studied.The results showed that the mechanical properties were basically identical with the whole coating;the hardness and modulus of elasticity of nanoindentation were evenly distributed in the defect field.The average hardness and modulus of elasticity of coating of Ni-based alloy are 8.29GPa and 235GPa.The average hardness and modulus of elasticity of coating of Co-based alloy are 7.08GPa and 243GPa.The modulus of elasticity of part of thin walls has relationship with the grain orientation.
基金Project(51461010101JB3501) supported by National Key Laboratory for High Energy Density Beam Processing Technology Foundation of China
文摘Laser engineered net shaping(LENS) process was investigated using Co-based superalloy powder with a high power continuous wave CO2 laser. Thin wall part with smooth surface was obtained by LENS of layer-by-layer deposition of the powder materials. This thin wall sample was tested for metallographic examinations, micro-hardness, X-ray diffraction and mechanical property test. Microstructural results show that the layers possess rapid solidification microstructural feature, fine dendritic crystal and M7C3-type carbides (essentially chromium-rich carbide) dispersed in theγ(Co,Cr) phase matrix. Dendrite spacing as well as the solidification mode can be controlled through control process parameters. In addition, this microstructural feature of the as-formed Co-base sample leads to an evident hardening and a superior tensile strength and toughness.
基金This work was financially supported by the National Key R&D Program of China(Grant No.2017YFB1103900)National Natural Science Foundation of China(Grant No.11972084)+1 种基金National Science and Technology Major Project(2017-VI-0003-0073)Beijing National Science Foundation(1192014).
文摘In this work,the evolution of melt pool under single-point and single-line printing in the laser engineered net shaping(LENS)process is analyzed.Firstly,the basic structure of the melt pool model of the LENS process is established and the necessary assumptions are made.Then,the establishment process of the multi-physical field model of the melt pool is introduced in detail.It is concluded that the simulation model results are highly consistent with the online measurement experiment results in terms of melt pool profile,space temperature gradient,and time temperature gradient.Meanwhile,some parameters,such as the 3D morphology and surface fluid field of the melt pool,which are not obtained in the online measurement experiment,are analyzed.Finally,the influence of changing the scanning speed on the profile,peak temperature,and temperature gradient of the single-line melt pool is also analyzed,and the following conclusions are obtained:With the increase in scanning speed,the profile of the melt pool gradually becomes slender;The relationship between peak temperature and scanning speed is approximately linear in a certain speed range;The space temperature gradient at the tail of the melt pool under different scanning speeds hardly changes with the scanning speed,and the time temperature gradient at the tail of the melt pool is in direct proportion to the scanning speed.
文摘The concepts of “confining structure” and structure light are illuminated in this paper.A laser theodolite with three freedoms of rotation,which is aimed at “confining structure”,is developed.Various scanning modes and their mathematical models based on laser theodolite with three freedoms of rotation are discussed.According to the features of a huge object,,the structure light engineering surveying based on laser theodolite with three freedoms of rotation is determined as the main method in an actual application.The observation of four sound concrete posts and forced centering plates.Subsequently,it is transformed into the huge object coordinate system.The scanning mode with plumb plane is selected as the main mode in the whole work.And other assistant methods,such as close range photogrammetry and the method of using reflection sheet,are applied to the work of “scanning dead angle”.At last,a surveying accuracy estimation of this method is done and a surveying accuracy test is finished.It can be concluded that the structure light engineering surveying based on laser theodolite with three freedoms of rotation is considered to be an effective and applied method,and has many superiority to some other surveying methods in the work of surveying “confining structure”.
文摘Purpose: Selective laser sintering (SLS) is a rapid pro- totyping technique applied to produce tissue-engineer- ing scaffolds from powder materials. The standard scanning technique, however, often produces struts of extensive thickness, which means fabrication of high- ly porous scaffolds with small overall dimensions is quite difficult. Nevertheless, this study aims to overcome this shortfall. Design/methodology/approach: To this end, three scanning methods were evaluated in terms of minimum feature size and freedom of design, using a test polyamide (PA) material. Polycaprolactone (PCL) was then employed to create highly porous 3D scaffolds using the preferred scanning me- thod to produce thin struts. Findings: While in normal scanning mode some features were well above the laser spot diameter, strut thicknesses below the laser spot diameter were achieved when using the “outline scan” function for PA material. Those achieved for PCL were slightly higher and in the 500-800 ?m range, with an average pore size of 400 μm. Investigations on the properties of the scaffolds revealed an effective compression modulus of the PCL scaffold of 6.5 MPa. Furthermore, there was no change in physical or che- mical properties when the scaffolds were stored in a physiological environment for 7 weeks. Originality/ value: Though SLS is considered as a fabrication te- chnique for tissue engineering scaffolds, actually pro- duced scaffolds did not comply with porosity requirements and limitations of the SLS process in produ- cing features at the size of the laser beam spot have not been discussed. The present paper shows the capabilities of the SLS process based on two materials and presents a method to minimize feature size in scaffolds.
基金supported by the National Nature1 Science Foundation of China(30170623)the National 863 Program of China(2001AA246013).
文摘MALDI-TOF-MS technology was used for identification of lipopeptide antibiotics producedby GEB3 strain, a derivative of Bacillus subtilis 168 which was transformed by lpaB3gene. The result showed GEB3 only produced lipopeptide antibiotic surfactin. The analysisby LC-MS demonstrated that GEB3 produced standard surfactin isoforms with side chainlengths of 13,14 and 15 carbon atoms. The bioactivity detection of surfactin indicatedthat the surfactin produced by GEB3 had inhibition effect on plant pathogens Rhizoctoniasolani and Pyricularia oryzae.
文摘In this paper,a series of new techniques are used to optimize typical laser scanning sensor.The integrated prototype is compared with traditional approach to demonstrate the much improved performance.In the research and development,camera calibration is achieved by extracting characteristic points of the laser plane,so that the calibra- tion efficiency is improved significantly.With feedback control of its intensity,the laser is automatically adjusted for different material.A modified algorithm is presented to improve the accuracy of laser stripe extraction.The fusion of data extracted from left and right camera is completed with re-sampling technique.The scanner is integrated with a robot arm and some other machinery for on-line measurement and inspection,which provides a flexible measurement tool for reverse engineering.
基金STI 2030-Major Projects(2022ZD0208601)National Natural Science Foundation of China(52105593)+2 种基金Zhejiang Provincial Natural Science Foundation of China(LDQ24E050001)‘Pioneer’and‘Leading Goose’R&D Program of Zhejiang(2023C01051)Fundamental Research Funds for the Central Universities(226-2024-00085)。
文摘Integration of sensors with engineering thermoplastics allows to track their health and surrounding stimuli.As one of vital backbones to construct sensor systems,copper(Cu)is highly conductive and cost-effective,yet tends to easily oxidize during and after processing.Herein,an in-situ integrated sensor system on engineering thermoplastics via hybrid laser direct writing is proposed,which primarily consists of laser-passivated functional Cu interconnects and laser-induced carbon-based sensors.Through a one-step photothermal treatment,the resulting functional Cu interconnects after reductive sintering and passivation are capable of resisting long-term oxidation failure at high temperatures(up to 170℃)without additional encapsulations.Interfacing with signal processing units,such an all-in-one system is applied for long-term and real-time temperature monitoring.This integrated sensor system with facile laser manufacturing strategies holds potentials for health monitoring and fault diagnosis of advanced equipment such as aircrafts,automobiles,high-speed trains,and medical devices.
基金863 Program grant number: 2077AA09Z436+1 种基金Guangdong Province '211' Fund for Biomaterials and Tissue Engineering grantnumber: 50621030
文摘A PVA-GAG-COL composite scaffold is fabricated by polyvinyl alcohol （PVA）, glyeosaminoglycan （GAG） and collagen （COL）. Laser surface modification technology is used to make holes on the surface of the scaffolds. Inside and outside interconnection micro-porous structure is obtained. Bioeompatibility test of the scaffolds shows that PVA-GAG-COL scaffold can promote the adhesion and proliferation of the fibroblast. Also, fibroblast can grow normally on the scaffolds with pore diameter from 115 um to 255 um and pore distance from 500 um to 2000 um. PVA-GAG-COL scaffolds possess excellent cell biocompatibility. The porous structure is suitable for cell culture in tissue engineering.
基金supported by National Key Research and Development Program of China(No.2023YFB3210400)Major Scientific and Technological Innovation Project of Shandong Province(No.2021CXGC010603)+1 种基金Natural Science Foundation of Shandong Province(Nos.ZR2020QE057,ZR2020QE071,ZR2020LLZ006)Innovative Team Project of Jinan(No.2021GXRC019)。
文摘Semiconductor-molecule surface-enhanced Raman scattering(SERS),especially the stronger interfacial charge transfer process(ICTP),represents a frontier in the field of SERS with spectral reproducibility and unparalleled selectivity.Herein,through a laser microfabrication method in situ,the free-standing,super hydrophilic and vacancy-rich TiO_(2-x)/Ti is successfully synthesized.Using blue TiO_(x)/Ti(B-TiO_(x)/Ti)as preconcentrated substrate,a nanomolar-level limit of detection of 12 nmol/L at 1385 cm–1,is confirmed using crystal violet(CV)bacteriostat as a model under 532 nm excitation.Furthermore,the results demonstrate that the SERS enhancement mechanism is via the moderate adulteration of oxygen vacancy,which leads to a narrow value of band gap and increases the ICTP of substrate to molecules.Using a hand-held extractor assembled with B-TiO_(x)/Ti microfiber,the operando analysis of mixtures distributed information excited in different parts of Asian carp is facilely achieved.This work guides the controlled synthesis of vacancy-rich TiO_(2-x)/Ti nanostructure and its application in ultrasensitive extraction-SERS detection.It also provides the direction for the rapid and operando transmission of biological information with temporal and spatial concentration distribution in human tissues by highly sensitized materials.
