Since the discovery of graphene, many efforts have been done to modify the graphene structure for integrating this novel material to nanoelectronics, fuel cells, energy storage devices and in many other applications. ...Since the discovery of graphene, many efforts have been done to modify the graphene structure for integrating this novel material to nanoelectronics, fuel cells, energy storage devices and in many other applications. This leads to the production of different types of graphene-based materials, which possess properties different from those of pure graphene. Porous graphene is an example of this type of materials. It can be considered as a graphene sheet with some holes/pores within the atomic plane. Due to its spongy structure, porous graphene can have potential applications as membranes for molecular sieving, energy storage components and in nanoelectronics. In this review, we present the recent progress in the synthesis of porous graphene. The properties and the potential applications of this new material are also discussed.展开更多
A new Nd3＋-doped organic complex featuring two different perfluorinated carboxylic acids as the first ligand and pyridine derivative 2-amino-3-chloro-5-（tri- fluoromethyl）pyridine as the second ligand was designed ...A new Nd3＋-doped organic complex featuring two different perfluorinated carboxylic acids as the first ligand and pyridine derivative 2-amino-3-chloro-5-（tri- fluoromethyl）pyridine as the second ligand was designed and synthesized. Successful coordination between the ligands and central rare earth ions was confirmed by Fourier transform infrared spectroscopy （FT-IR） spectra, 1H nuclear magnetic resonance （1H NMR） spectra, and UV spectra, and the synthesized complex is inferred to be eight-coordinate structure. Solution of the complex dis- solved in DMSO-d6 was prepared and then its fluorescence spectrum, UV-Vis-NIR absorption spectrum, and fluorescence decay curve were tested. The fluorescent lifetime is about 7 txs. Based on the above experimental research, Judd-Ofelt analysis was carried out, and the results indi- cate that appropriate coordination environment around Nd3＋ in this solution results in a high fluorescent quantum efficiency 2 % and a large stimulated emission cross-section about 3.2 × 10^-20 cm^2 at 1,064 nm.展开更多
We report an experimental study on a double-arched LD array stagger pumped electro-optic Q-switched Nd：YAG laser without water cooling by using a convex-concave compensate resonator. Perfect matching of the gain fiel...We report an experimental study on a double-arched LD array stagger pumped electro-optic Q-switched Nd：YAG laser without water cooling by using a convex-concave compensate resonator. Perfect matching of the gain field inside the rod and the fundamental mode of the cavity is made by this structure. When the repetition rate is 20 Hz, A maximum output energy at 1064 nm wavelength of 176 mJ （M2=1.55） and 9.6 ns FWHM pulse width in fundamental mode Q-switch operation is obtained with LD injection current 120 A. The optical-optical conversion efficiency is 14.7%, the divergence angle of the output beam is about 1.8 mrad.展开更多
Perovskite nanostructured films are essential to create advanced optoelectronic and photovoltaic devices because of the additional degrees of freedom of manipulation by light reflection and structural colouration,as w...Perovskite nanostructured films are essential to create advanced optoelectronic and photovoltaic devices because of the additional degrees of freedom of manipulation by light reflection and structural colouration,as well as by light trapping and localisation,resulting in control of intensity or polarisation of luminescence.In this paper,we report structural colouration and photoluminescence anisotropy in perovskite films deposited on a substrate with laser-induced periodic surface structures(LIPSSs)on a thin TiO_(2)layer.The LIPSS TiO_(2)layer improves charge extraction from the perovskite films,confirmed by a time-resolved photoluminescence analysis.The developed method of substrate nanostructuring does not damage the perovskite films,in contrast to direct laser ablation,imprinting by a mould,mechanical scratching with a cantilever,or plasma-chemical etching.Moreover,the LIPSS formation is appropriate for upscaling owing to the high speed of LIPSS writing(2.25 cm^(2)min^(-1))and uniform surface nanostructuring.展开更多
The anti-misalignment stability and output characteristics of the right angle cone cavity laser are experi- mentally studied. When the misalignment angle of the cone mirror turns to 46.8 minutes, the single-pulse outp...The anti-misalignment stability and output characteristics of the right angle cone cavity laser are experi- mentally studied. When the misalignment angle of the cone mirror turns to 46.8 minutes, the single-pulse output energy of the piano-cone cavity laser decreases 24% and the near-field beam patterns have little change; as for the beam directional stability, when the measuring place stands 3.12 m in front of the output mirror, the near-field beam patterns of the piano-cone laser are located at the primary places until the misalignment angle of the cone mirror turns to 18 minutes. These results show that the piano-cone cavity laser has better performances in comparison with the piano-concave cavity laser.The analytical results of the mode instrument are also obtained, which show that the near-field beam intensity distribution of the piano-cone mirror cavity laser is near to the plane wave.展开更多
We have optimized the input pulse width and injection time to achieve the highest possible output pulse energy in a double-pass laser amplifier using two Nd:YAG rods. For this purpose, we have extended the Frantz–Nod...We have optimized the input pulse width and injection time to achieve the highest possible output pulse energy in a double-pass laser amplifier using two Nd:YAG rods. For this purpose, we have extended the Frantz–Nodvik equation by simultaneously including both spontaneous emission and pump energy variation. The effective pump energy of the flash lamp was 8.84 J for each gain medium. The energy of 1 J could be amplified to an output energy of 12.17 J with the maximum achieved extraction efficiency of 63.18% when an input pulse having a pulse width of 168 μs is sent 10 μs after the absorbed pump energy becomes the maximum value.展开更多
Off-line programming provides an essential link for CAD/CAM. This paper introduced the principle of developing off-line programming system for laser re-manufacturing. Task and information flow of off-line programming ...Off-line programming provides an essential link for CAD/CAM. This paper introduced the principle of developing off-line programming system for laser re-manufacturing. Task and information flow of off-line programming for laser re-manufacturing robot was analyzed and the software structure of off-line programming based on commercial CAD software was constructed. The off-line programming system developed in this study includes 3-D solid model design, direct slicing for obtaining path data, graphical simulation of the robot and its workcell, kinematic model of the robot, motion planning, and creation of the control program for manufacturing process. The CAD software was used to design models of robot, workpiece, coaxial nozzle, and workspace. Through the application programming interface provided by the CAD software, the VC++ and ATL were chosen to develop such modules as direct slicing for obtaining path data, path planning, process specification, and control program automatic generation. The FANUC Roboguide software was used to realize graphical simulation. By direct slicing, the position and orientation data of robot end-effector was determined. The results show that the proposed system can be applied in laser re-manufacturing robot for manufacturing operations.展开更多
A high power continuous-wave deep blue laser at 447 nm is obtained by using a doubly cavity and a type H critical phase matching KTP crystal for intracavity sum-frequency-mixing. With the incident pump power of 240 W ...A high power continuous-wave deep blue laser at 447 nm is obtained by using a doubly cavity and a type H critical phase matching KTP crystal for intracavity sum-frequency-mixing. With the incident pump power of 240 W for the Nd：YAP crystal and 120 W for the other Nd：YAP crystal, the deep blue laser output of 5.7 W at 447 nm with near fundamental mode is obtained, and the beam quality M^2 value equals 2.53 in both horizontal and vertical directions at the maximum output power. The power stability is better than 2% at the maximum output power during half an hour. The experimental results show that the intracavity sum-frequency mixing by doubly resonant is an effective method for high power blue laser.展开更多
The ion laser actions of C1, 0, N were reported. We have obtained two new UV oxygen lasex lines by discharging with pure oxygen.Sixty-two UV and visible ion laser lines of Cl, O, N, Ti, among which 20 are new, were ob...The ion laser actions of C1, 0, N were reported. We have obtained two new UV oxygen lasex lines by discharging with pure oxygen.Sixty-two UV and visible ion laser lines of Cl, O, N, Ti, among which 20 are new, were observed by means of longitudinal pulsed discharge with or without an inductance coil connected with the discharge circuit to control the peak discharge current so as to stimulate the laser oscillations of the lower multiple ion stage or the higher multiple ion stage. The pulse du-展开更多
New laser line, especially new UV laser, has been the frontier of laser exploration. The kinds of laser medium hitherto used are still far from abundant and the number of laser lines still relatively few. It can be pr...New laser line, especially new UV laser, has been the frontier of laser exploration. The kinds of laser medium hitherto used are still far from abundant and the number of laser lines still relatively few. It can be proved that any kind of pure substance is surely one for laser action. Both sulphur and oxygen are laser media, whose laser展开更多
A novel experiment method for chemical solubility determination was brought forward, in which optics and chemistry principles are united and the change of laser intensity indicates the process of chemical dissolving. ...A novel experiment method for chemical solubility determination was brought forward, in which optics and chemistry principles are united and the change of laser intensity indicates the process of chemical dissolving. The more undissolved solid exists in the mixture of solute and solvent, the less transmitted laser intensity is detected. Only when the transmitted laser intensity in stirring state and that in static state comes into equalization, the dissolving process stops. Under the help of laser intensity judgement, measurements turn to be more feasible and objective, especially at high pressure. The average relative errors for the solubility data determined in this paper are 2.3% for those in the minor value scope and 1.7% for those in the high value scope respectively. Comparison of the experimental solubility data with the literature ones demonstrates that the laser-aid solubility determination apparatus is stable and reliable.展开更多
Background:Poor sleep quality is associated with a decrease in quality of life in patients with major burn scars,combined with pruritus and pain.Few interventions have been reported to improve the sleep quality of pat...Background:Poor sleep quality is associated with a decrease in quality of life in patients with major burn scars,combined with pruritus and pain.Few interventions have been reported to improve the sleep quality of patients with scars.In the current prospective cohort study,we investigated the efficacy of CO_(2)-ablative fractional laser(AFL)surgery vs conventional surgery in post-burn patients with hypertrophic scars with sleep quality as the primary study outcome.Methods:In total 68 consecutive patients undergoing scar surgical treatment were recruited,including a CO_(2)-AFL surgery cohort(n=35)and a conventional surgery cohort(n=33).A subgroup from the AFL cohort was selected.Sleep quality,pain and pruritus were evaluated.Multiple linear regression analyses were performed to reveal the effect of CO_(2)-AFL surgery.Results:The CO_(2)-AFL surgery cohort had significantly lower Pittsburgh sleep quality index(PSQI)global scores than the conventional surgery cohort after the last surgical treatment.In the subgroup of patients receiving hardware sleep monitoring,CO_(2)-AFL markedly increased deep sleep time,deep sleep efficiency and reduced initial sleep latency.Compared to the conventional surgery cohort,the CO_(2)-AFL cohort presented significantly lower pain and pruritus scores.Correlation analysis showed pain and pruritus were significantly associated with PSQI scores,and there were also significant correlations between pain and pruritus scores.Multiple linear regression analysis showed that surgery method was negatively linearly correlated with visual analog scale(VAS)pain score,brief pain inventory(BPI)total,VAS pruritus score,5-D itch scale total,four-item itch questionnaire(FIIQ)total and PSQI total.Conclusions:CO_(2)-AFL surgery significantly improved sleep quality and reduced pain and pruritus of hypertrophic scar patients.The alleviation of sleep disorder was associated with improvement of deep sleep quality including deep sleep time and deep sleep deficiency.Trial registration:The Chinese Clinical Trial Registry(ChiCTR200035268)approved retrospectively registration on 5 Aug 2020.展开更多
In this paper, we theoretically deduce the expressions of half-wave voltage and 3-dB modulation bandwidth in which conductor loss is taken into account. The results suggest that it will affect the theoretical values o...In this paper, we theoretically deduce the expressions of half-wave voltage and 3-dB modulation bandwidth in which conductor loss is taken into account. The results suggest that it will affect the theoretical values of half-wave voltage and bandwidth as well as the optimized electrode's dimension whether considering the conductor loss or not. As an example, we present a Mach-Zehnder (MZ) type polymer waveguide amplitude modulator. The half-wave voltage increases by 1 V and the 3-dB bandwidth decreases by 30% when the conductor loss is taken into account. Besides, the effects of impedance mismatching and velocity mismatching between microwave and light wave on the half-wave voltage, and 3-dB bandwidth are discussed.展开更多
The degree of penetration can directly reflect the forming quality of laser welding. The fine-grained feature of the molten pool/keyhole image brings challenges to the vision-based laser welding penetration status rec...The degree of penetration can directly reflect the forming quality of laser welding. The fine-grained feature of the molten pool/keyhole image brings challenges to the vision-based laser welding penetration status recognition. In this paper, a novel knowledge-and-data-hybrid driven recognition model is proposed for solving the problem of difficult learning of discriminative visual features of molten pool/keyhole images. In addition, a label semantic attention mechanism(LSA) is designed with three modules: representation of image visual feature, representation of labels semantic feature, and generation of label semantic attention. For learning discriminative features in visual space, LSA uses discriminative information in label semantics to guide the convolutional neural network. The experimental results show that the proposed LSA method has faster convergence and higher accuracy than the traditional attention mechanism. Further comparative experiments reveal that LSA is less dependent on the amount of training data and model complexity. The results of visualization experiments show that the visual features learned by the proposed method are more discriminative.展开更多
As a new research area, laser surface wettability modification brings new applications for both laser and materials for industry. The picoseconds （10 ps） pulse laser surface micro-processing over alumina covered alu...As a new research area, laser surface wettability modification brings new applications for both laser and materials for industry. The picoseconds （10 ps） pulse laser surface micro-processing over alumina covered aluminium is researched. In the experiment, lO-ps laser pulse is employed and the energy threshold for different laser wavelength and repetition rate is measured. At the repetition rate of 5 kHz, the energy thresholds are： 1064 nm： 4.0 μJ/pulse, 532 nm： 2.8 μJ/pulse, and 355 nm： 4.2 #J/pulse. Picoseconds pulse laser is demonstrated feasible in surface scanning at industrial level.展开更多
Artificial intelligence(AI),characterized by its capability in learning,comprehension,and problem solving,has emerged as a driving force in numerous fields,including photonics.The recent Nobel Prizes in physics and ch...Artificial intelligence(AI),characterized by its capability in learning,comprehension,and problem solving,has emerged as a driving force in numerous fields,including photonics.The recent Nobel Prizes in physics and chemistry serve as a testament to AI’s transformative capabilities,showcasing its ability to solve intricate problems and make significant discoveries.In the realm of photonics,AI has opened doors to unprecedented advancements,from the design of novel materials and devices to the optimization of imaging systems and the enhancement of sensing capabilities.展开更多
A novel light scanning system based on circular laser trajectory for welding robot is developed. With the help of image processing technique, intelligent laser welding could be realized. According to laser triangulati...A novel light scanning system based on circular laser trajectory for welding robot is developed. With the help of image processing technique, intelligent laser welding could be realized. According to laser triangulation algorithm and Scheimpflug condition, mathematical model for circular laser vision is built. This scanning system projects circular laser onto welded seams and recovers the depth of the welded seams, escapes from shortcomings of less information, explains ambiguity and single tracking direction inherent in “spot” or “line” type laser trajectory. Three-dimensional （3D） model for welded seams could be recognized after depth recovery. The imaging error is investigated also.展开更多
Investigation of isotope shift（IS） of optical transition is a very important method to obtain the nuclear parameters of an atom. The previous reports on investigation of isotope shifts of Hg were principally focused...Investigation of isotope shift（IS） of optical transition is a very important method to obtain the nuclear parameters of an atom. The previous reports on investigation of isotope shifts of Hg were principally focused on the strong transitions, such as 6<sup>1</sup>S<sub>0</sub>—6<sup>3</sup>P<sub>1</sub>（2537） and 6<sup>3</sup>P<sub>2</sub>—7<sup>3</sup>S<sub>1</sub>（5461）. And in the analysis of the isotope shift, the contribution of p electron was completely ignored due to the contribution of s electron being greatly larger than that ofp electron. These led to the ignorance of the information on p electron.展开更多
Imaging systems based on metasurfaces have advantages in terms of integration and flexibility.Here,we present a single-layer metasurface for a snapshot high-dynamic-range(HDR)imaging scheme(SiM-SHDR).The metasurface c...Imaging systems based on metasurfaces have advantages in terms of integration and flexibility.Here,we present a single-layer metasurface for a snapshot high-dynamic-range(HDR)imaging scheme(SiM-SHDR).The metasurface can integrate functions of multiple components found in traditional HDR imaging systems.Benefiting from the polarization-independent full-space amplitude and phase control mechanism,the single-layer metasurface is capable of capturing multiple high-fidelity images with different levels of intensity in a single shot.After fusing the images,the dynamic range of the pictures can be effectively extended.Using a dual-channel image capture configuration with an intensity ratio of 10:1,the dynamic range can theoretically be enhanced by up to 20 dB.Experimental results in our demonstrated imaging system show the dynamic range improvement can reach 17.5 dB and even more.This metasurface design maintains a similar weight and volume to traditional single-image acquisition systems,making it ideal for lightweight,ultra-compact,and real-time HDR imaging in applications like surveillance,industrial manufacturing,and driving.展开更多
基金partially supported by the Natural Science and Engineering Council of Canada (NSERC, Canada)the financial support from the high level overseas talent project of Beijing, P. R. China
文摘Since the discovery of graphene, many efforts have been done to modify the graphene structure for integrating this novel material to nanoelectronics, fuel cells, energy storage devices and in many other applications. This leads to the production of different types of graphene-based materials, which possess properties different from those of pure graphene. Porous graphene is an example of this type of materials. It can be considered as a graphene sheet with some holes/pores within the atomic plane. Due to its spongy structure, porous graphene can have potential applications as membranes for molecular sieving, energy storage components and in nanoelectronics. In this review, we present the recent progress in the synthesis of porous graphene. The properties and the potential applications of this new material are also discussed.
基金supported by the Natural Science Foundation of Jiangsu Higher Education Institutions of China (No. 08KJD430009)Jiangsu University Senior Talent Starting Fund (No. 08JDG025)
文摘A new Nd3＋-doped organic complex featuring two different perfluorinated carboxylic acids as the first ligand and pyridine derivative 2-amino-3-chloro-5-（tri- fluoromethyl）pyridine as the second ligand was designed and synthesized. Successful coordination between the ligands and central rare earth ions was confirmed by Fourier transform infrared spectroscopy （FT-IR） spectra, 1H nuclear magnetic resonance （1H NMR） spectra, and UV spectra, and the synthesized complex is inferred to be eight-coordinate structure. Solution of the complex dis- solved in DMSO-d6 was prepared and then its fluorescence spectrum, UV-Vis-NIR absorption spectrum, and fluorescence decay curve were tested. The fluorescent lifetime is about 7 txs. Based on the above experimental research, Judd-Ofelt analysis was carried out, and the results indi- cate that appropriate coordination environment around Nd3＋ in this solution results in a high fluorescent quantum efficiency 2 % and a large stimulated emission cross-section about 3.2 × 10^-20 cm^2 at 1,064 nm.
文摘We report an experimental study on a double-arched LD array stagger pumped electro-optic Q-switched Nd：YAG laser without water cooling by using a convex-concave compensate resonator. Perfect matching of the gain field inside the rod and the fundamental mode of the cavity is made by this structure. When the repetition rate is 20 Hz, A maximum output energy at 1064 nm wavelength of 176 mJ （M2=1.55） and 9.6 ns FWHM pulse width in fundamental mode Q-switch operation is obtained with LD injection current 120 A. The optical-optical conversion efficiency is 14.7%, the divergence angle of the output beam is about 1.8 mrad.
基金the Interdisciplinary Resource Center for Nanotechnology of Saint Petersburg State University within the framework of project no.AAAAA19-119091190094supported by the Russian Science Foundation(project no.24-62-00022)Priority 2030 Federal Academic Leadership Program.
文摘Perovskite nanostructured films are essential to create advanced optoelectronic and photovoltaic devices because of the additional degrees of freedom of manipulation by light reflection and structural colouration,as well as by light trapping and localisation,resulting in control of intensity or polarisation of luminescence.In this paper,we report structural colouration and photoluminescence anisotropy in perovskite films deposited on a substrate with laser-induced periodic surface structures(LIPSSs)on a thin TiO_(2)layer.The LIPSS TiO_(2)layer improves charge extraction from the perovskite films,confirmed by a time-resolved photoluminescence analysis.The developed method of substrate nanostructuring does not damage the perovskite films,in contrast to direct laser ablation,imprinting by a mould,mechanical scratching with a cantilever,or plasma-chemical etching.Moreover,the LIPSS formation is appropriate for upscaling owing to the high speed of LIPSS writing(2.25 cm^(2)min^(-1))and uniform surface nanostructuring.
文摘The anti-misalignment stability and output characteristics of the right angle cone cavity laser are experi- mentally studied. When the misalignment angle of the cone mirror turns to 46.8 minutes, the single-pulse output energy of the piano-cone cavity laser decreases 24% and the near-field beam patterns have little change; as for the beam directional stability, when the measuring place stands 3.12 m in front of the output mirror, the near-field beam patterns of the piano-cone laser are located at the primary places until the misalignment angle of the cone mirror turns to 18 minutes. These results show that the piano-cone cavity laser has better performances in comparison with the piano-concave cavity laser.The analytical results of the mode instrument are also obtained, which show that the near-field beam intensity distribution of the piano-cone mirror cavity laser is near to the plane wave.
基金supported by the Industrial Strategic Technology development program,10048964the Ministry of Trade,Industry&Energy(MI,Korea)
文摘We have optimized the input pulse width and injection time to achieve the highest possible output pulse energy in a double-pass laser amplifier using two Nd:YAG rods. For this purpose, we have extended the Frantz–Nodvik equation by simultaneously including both spontaneous emission and pump energy variation. The effective pump energy of the flash lamp was 8.84 J for each gain medium. The energy of 1 J could be amplified to an output energy of 12.17 J with the maximum achieved extraction efficiency of 63.18% when an input pulse having a pulse width of 168 μs is sent 10 μs after the absorbed pump energy becomes the maximum value.
基金Supported by the Science and Technology Development Project of Tianjin Colleges and Universities (No. 20071108)the Key Project of Tianjin Science and Technology Committee (No.08ZCKFGX02300)
文摘Off-line programming provides an essential link for CAD/CAM. This paper introduced the principle of developing off-line programming system for laser re-manufacturing. Task and information flow of off-line programming for laser re-manufacturing robot was analyzed and the software structure of off-line programming based on commercial CAD software was constructed. The off-line programming system developed in this study includes 3-D solid model design, direct slicing for obtaining path data, graphical simulation of the robot and its workcell, kinematic model of the robot, motion planning, and creation of the control program for manufacturing process. The CAD software was used to design models of robot, workpiece, coaxial nozzle, and workspace. Through the application programming interface provided by the CAD software, the VC++ and ATL were chosen to develop such modules as direct slicing for obtaining path data, path planning, process specification, and control program automatic generation. The FANUC Roboguide software was used to realize graphical simulation. By direct slicing, the position and orientation data of robot end-effector was determined. The results show that the proposed system can be applied in laser re-manufacturing robot for manufacturing operations.
基金supported by the Education Department Foundation of Jilin Province under Grant No.2007-36
文摘A high power continuous-wave deep blue laser at 447 nm is obtained by using a doubly cavity and a type H critical phase matching KTP crystal for intracavity sum-frequency-mixing. With the incident pump power of 240 W for the Nd：YAP crystal and 120 W for the other Nd：YAP crystal, the deep blue laser output of 5.7 W at 447 nm with near fundamental mode is obtained, and the beam quality M^2 value equals 2.53 in both horizontal and vertical directions at the maximum output power. The power stability is better than 2% at the maximum output power during half an hour. The experimental results show that the intracavity sum-frequency mixing by doubly resonant is an effective method for high power blue laser.
文摘The ion laser actions of C1, 0, N were reported. We have obtained two new UV oxygen lasex lines by discharging with pure oxygen.Sixty-two UV and visible ion laser lines of Cl, O, N, Ti, among which 20 are new, were observed by means of longitudinal pulsed discharge with or without an inductance coil connected with the discharge circuit to control the peak discharge current so as to stimulate the laser oscillations of the lower multiple ion stage or the higher multiple ion stage. The pulse du-
文摘New laser line, especially new UV laser, has been the frontier of laser exploration. The kinds of laser medium hitherto used are still far from abundant and the number of laser lines still relatively few. It can be proved that any kind of pure substance is surely one for laser action. Both sulphur and oxygen are laser media, whose laser
基金The authors would like to thank SINOPEC Joint-stock Company for the financial support(No. 200049).
文摘A novel experiment method for chemical solubility determination was brought forward, in which optics and chemistry principles are united and the change of laser intensity indicates the process of chemical dissolving. The more undissolved solid exists in the mixture of solute and solvent, the less transmitted laser intensity is detected. Only when the transmitted laser intensity in stirring state and that in static state comes into equalization, the dissolving process stops. Under the help of laser intensity judgement, measurements turn to be more feasible and objective, especially at high pressure. The average relative errors for the solubility data determined in this paper are 2.3% for those in the minor value scope and 1.7% for those in the high value scope respectively. Comparison of the experimental solubility data with the literature ones demonstrates that the laser-aid solubility determination apparatus is stable and reliable.
基金supported by the Special Scientific Research Fund of the Public Welfare Profession of China(201502028)the Excellent Discipline Leader Training Program of Shanghai Health System(No.2017BR037)+2 种基金the NationalNatural Science Foundation of China(No.81772091)Clinical Research Plan of Shanghai Hospital Devel-opment Center(No.SHDC2020CR3039B)Shanghai Rising-Star Program(17QB1403300).
文摘Background:Poor sleep quality is associated with a decrease in quality of life in patients with major burn scars,combined with pruritus and pain.Few interventions have been reported to improve the sleep quality of patients with scars.In the current prospective cohort study,we investigated the efficacy of CO_(2)-ablative fractional laser(AFL)surgery vs conventional surgery in post-burn patients with hypertrophic scars with sleep quality as the primary study outcome.Methods:In total 68 consecutive patients undergoing scar surgical treatment were recruited,including a CO_(2)-AFL surgery cohort(n=35)and a conventional surgery cohort(n=33).A subgroup from the AFL cohort was selected.Sleep quality,pain and pruritus were evaluated.Multiple linear regression analyses were performed to reveal the effect of CO_(2)-AFL surgery.Results:The CO_(2)-AFL surgery cohort had significantly lower Pittsburgh sleep quality index(PSQI)global scores than the conventional surgery cohort after the last surgical treatment.In the subgroup of patients receiving hardware sleep monitoring,CO_(2)-AFL markedly increased deep sleep time,deep sleep efficiency and reduced initial sleep latency.Compared to the conventional surgery cohort,the CO_(2)-AFL cohort presented significantly lower pain and pruritus scores.Correlation analysis showed pain and pruritus were significantly associated with PSQI scores,and there were also significant correlations between pain and pruritus scores.Multiple linear regression analysis showed that surgery method was negatively linearly correlated with visual analog scale(VAS)pain score,brief pain inventory(BPI)total,VAS pruritus score,5-D itch scale total,four-item itch questionnaire(FIIQ)total and PSQI total.Conclusions:CO_(2)-AFL surgery significantly improved sleep quality and reduced pain and pruritus of hypertrophic scar patients.The alleviation of sleep disorder was associated with improvement of deep sleep quality including deep sleep time and deep sleep deficiency.Trial registration:The Chinese Clinical Trial Registry(ChiCTR200035268)approved retrospectively registration on 5 Aug 2020.
文摘In this paper, we theoretically deduce the expressions of half-wave voltage and 3-dB modulation bandwidth in which conductor loss is taken into account. The results suggest that it will affect the theoretical values of half-wave voltage and bandwidth as well as the optimized electrode's dimension whether considering the conductor loss or not. As an example, we present a Mach-Zehnder (MZ) type polymer waveguide amplitude modulator. The half-wave voltage increases by 1 V and the 3-dB bandwidth decreases by 30% when the conductor loss is taken into account. Besides, the effects of impedance mismatching and velocity mismatching between microwave and light wave on the half-wave voltage, and 3-dB bandwidth are discussed.
基金supported by the Fundamental Research Funds for the Central Universities and Graduate Student Innovation Fund of Donghua University(Grant No.CUSF-DH-D-2020053)。
文摘The degree of penetration can directly reflect the forming quality of laser welding. The fine-grained feature of the molten pool/keyhole image brings challenges to the vision-based laser welding penetration status recognition. In this paper, a novel knowledge-and-data-hybrid driven recognition model is proposed for solving the problem of difficult learning of discriminative visual features of molten pool/keyhole images. In addition, a label semantic attention mechanism(LSA) is designed with three modules: representation of image visual feature, representation of labels semantic feature, and generation of label semantic attention. For learning discriminative features in visual space, LSA uses discriminative information in label semantics to guide the convolutional neural network. The experimental results show that the proposed LSA method has faster convergence and higher accuracy than the traditional attention mechanism. Further comparative experiments reveal that LSA is less dependent on the amount of training data and model complexity. The results of visualization experiments show that the visual features learned by the proposed method are more discriminative.
文摘As a new research area, laser surface wettability modification brings new applications for both laser and materials for industry. The picoseconds （10 ps） pulse laser surface micro-processing over alumina covered aluminium is researched. In the experiment, lO-ps laser pulse is employed and the energy threshold for different laser wavelength and repetition rate is measured. At the repetition rate of 5 kHz, the energy thresholds are： 1064 nm： 4.0 μJ/pulse, 532 nm： 2.8 μJ/pulse, and 355 nm： 4.2 #J/pulse. Picoseconds pulse laser is demonstrated feasible in surface scanning at industrial level.
文摘Artificial intelligence(AI),characterized by its capability in learning,comprehension,and problem solving,has emerged as a driving force in numerous fields,including photonics.The recent Nobel Prizes in physics and chemistry serve as a testament to AI’s transformative capabilities,showcasing its ability to solve intricate problems and make significant discoveries.In the realm of photonics,AI has opened doors to unprecedented advancements,from the design of novel materials and devices to the optimization of imaging systems and the enhancement of sensing capabilities.
基金This work was supported by Scientific Program of Science and Technology Department of Shanghai (No. 036105001) and Oversea Science and Technology Corporation Key Program (China-Germany) (No. 2004DFA02400).
文摘A novel light scanning system based on circular laser trajectory for welding robot is developed. With the help of image processing technique, intelligent laser welding could be realized. According to laser triangulation algorithm and Scheimpflug condition, mathematical model for circular laser vision is built. This scanning system projects circular laser onto welded seams and recovers the depth of the welded seams, escapes from shortcomings of less information, explains ambiguity and single tracking direction inherent in “spot” or “line” type laser trajectory. Three-dimensional （3D） model for welded seams could be recognized after depth recovery. The imaging error is investigated also.
基金Project supported by the National Natural Science Foundation of China
文摘Investigation of isotope shift（IS） of optical transition is a very important method to obtain the nuclear parameters of an atom. The previous reports on investigation of isotope shifts of Hg were principally focused on the strong transitions, such as 6<sup>1</sup>S<sub>0</sub>—6<sup>3</sup>P<sub>1</sub>（2537） and 6<sup>3</sup>P<sub>2</sub>—7<sup>3</sup>S<sub>1</sub>（5461）. And in the analysis of the isotope shift, the contribution of p electron was completely ignored due to the contribution of s electron being greatly larger than that ofp electron. These led to the ignorance of the information on p electron.
基金National Natural Science Foundation of China(12104472,62325508,61991452,62061136005,U22A2080)Program of Shanghai Academic Research Leader(22XD1403900)Shanghai Municipal Science and Technology Major Project。
文摘Imaging systems based on metasurfaces have advantages in terms of integration and flexibility.Here,we present a single-layer metasurface for a snapshot high-dynamic-range(HDR)imaging scheme(SiM-SHDR).The metasurface can integrate functions of multiple components found in traditional HDR imaging systems.Benefiting from the polarization-independent full-space amplitude and phase control mechanism,the single-layer metasurface is capable of capturing multiple high-fidelity images with different levels of intensity in a single shot.After fusing the images,the dynamic range of the pictures can be effectively extended.Using a dual-channel image capture configuration with an intensity ratio of 10:1,the dynamic range can theoretically be enhanced by up to 20 dB.Experimental results in our demonstrated imaging system show the dynamic range improvement can reach 17.5 dB and even more.This metasurface design maintains a similar weight and volume to traditional single-image acquisition systems,making it ideal for lightweight,ultra-compact,and real-time HDR imaging in applications like surveillance,industrial manufacturing,and driving.
