An eco-friendly rust converter treatment based on tannic acid was optimized by orthogonal experiment, and the adhesion of the epoxy top-coating system was evaluated. The results showed that the adhesion between the ep...An eco-friendly rust converter treatment based on tannic acid was optimized by orthogonal experiment, and the adhesion of the epoxy top-coating system was evaluated. The results showed that the adhesion between the epoxy coating and the rusted steel after treatment was enhanced from 1.93 to 5.97 MPa. This adhesion improvement was attributed to the formation of the micro-cracked tannic conversion layer and the increase of the compactness of the rust layer. The failure analysis suggested that the remainder rust was still the key issue for the further adhesion improvement of the coating system.展开更多
Chloride-induced corrosion of steel reinforcement is the key factor leading to the degradation of reinforced concrete building durability.Improving the corrosion resistance of oxide scale of rebar has always been a re...Chloride-induced corrosion of steel reinforcement is the key factor leading to the degradation of reinforced concrete building durability.Improving the corrosion resistance of oxide scale of rebar has always been a research hotspot in the field of civil engineering materials.A ZIF-8 modified Ce-Sol-gel(ZCS)film was prepared on oxide scale of plain steel rebars by sol-gel method.It is observed that the|Z|_(0.01 Hz)value of the ZCS film reached 320 kΩcm^(2),which is about 29 times higher than that of blank rebar in simulated concrete pore(SCP)solution with 0.1 M NaCl.Then,they were inserted into mortar block and curing them in a curing box at T=20±2℃and RH=95±2%for 28 days.Subsequently,these samples were subject to electrochemical impedance spectroscopy in 3.5 wt%NaCl.The|Z|_(0.01 Hz)value of the rebar with the ZCS film was six times higher than that of the blank rebar after immersing for 20 days,resulting in an overall increase in corrosion resistance for rebar.The results indicated that the modification by ZIF-8 could reduce the porosity of Ce-sol-gel(CS)film and improved the“labyrinth effect”of the film.Additionally,the negative charge on the surface of ZIF-8 in alkaline condition increased the repulsion effect with Cl−,significantly reducing the sensitivity of rebar to Cl−.展开更多
Organic coatings are commonly used to protect the metals or alloys from corrosion.However,defects such as scratches or natural aging of the coating can induce unexpected diffusion paths for the corrosive media,so the ...Organic coatings are commonly used to protect the metals or alloys from corrosion.However,defects such as scratches or natural aging of the coating can induce unexpected diffusion paths for the corrosive media,so the wettability of repairing liquids and the selection of suitable repairing liquids are crucial.In this study,we systematically investigated the capillary impregnation phenomenon by using liquids with various surface tensions and glass capillaries with different surface energies.We utilized this regularity to instruct the defects repairing process.By using an ultra-depth field microscope,scanning electron mi-croscope,and electrochemical analysis,two kinds of repairing liquids,high surface tension liquid(HSTL)and low surface tension liquid(LSTL),were investigated for repairing man-made defects of coatings.Our results showed that the substrate and the surface energy of the liquids significantly influence the infil-tration of the repair liquid.By effectively leveraging the relationship between the repair liquid and the substrate,the repair agent can not only establish a uniform and dense repairing layer but also notably enhance the corrosion resistance of the defective coating.This study provides valuable insights into the repairing of coating defects,as well as liquids transportation,microfluidic chip design,and surface modi-fication of microporous materials.展开更多
In this study,basalt scales were activated by air plasma and were subsequently deposited with cerium dioxide nanoparticles to obtain CeO_(2)-modified basalts(CB).Inspired by mussel biomimetics,polydopamine(PDA)and 3-g...In this study,basalt scales were activated by air plasma and were subsequently deposited with cerium dioxide nanoparticles to obtain CeO_(2)-modified basalts(CB).Inspired by mussel biomimetics,polydopamine(PDA)and 3-glycidoxypropyltrimethoxysilane were further employed to modify the properties of CB to obtain functionalized basalt scales(CBD).This treatment greatly increased the interfacial compatibility between inorganic fillers and epoxy resin.At the same time,PDA can form chelates with iron ions in the anodic area to prevent further corrosion.Tensile,water absorption,and electrochemical impedance spectrum measurements showed that incorporating CBD into epoxy resins resulted in the composite coatings with higher mechanical properties,water penetration resistance,corrosion resistance,and lower wetting properties.展开更多
BACKGROUND Chronic granulomatous disease(CGD)characterized by recurrent and severe bacterial and fungal infections is most common in childhood.CASE SUMMARY We reported a 24-d-old male infant who developed gastrointest...BACKGROUND Chronic granulomatous disease(CGD)characterized by recurrent and severe bacterial and fungal infections is most common in childhood.CASE SUMMARY We reported a 24-d-old male infant who developed gastrointestinal symptoms as the first sign of CGD.CONCLUSION Gastrointestinal symptoms representing the first sign of CGD are very rare,and prompt diagnosis and treatment with broad-spectrum antibiotics were of crucial importance.展开更多
Broadband polarization measurement plays a crucial role in numerous fields,spanning from fundamental physics to a wide range of practical applications.However,traditional approaches typically rely on combinations of v...Broadband polarization measurement plays a crucial role in numerous fields,spanning from fundamental physics to a wide range of practical applications.However,traditional approaches typically rely on combinations of various dispersive optical elements,requiring bulky systems and complicated time-consuming multiple procedures.Here we have achieved broadband spectropolarimetry based on single-shot images for spatial intensity distributions of polychromatic vector beams.A custom-designed diffractive optical element and a vortex retarder convert the incident polychromatic waves into structured vector beams:the former diffracts light of different wavelengths into concentric circles of different radii,while the latter codes their polarization information into intensity distributions along the azimuthal direction.The validation experiments verify our exceptional measurement accuracy(RMS errors<1%)for each Stokes component in the visible light range(400-700 nm),with good spectral(<0.8 nm)and temporal(an output rate of 100 Hz)resolutions.We have further employed our broadband polarimeter to study the mutarotation of glucose,making direct observations of temporal evolutions of chemical reactions accessible.Our work has significantly broadened the toolboxes of spectropolarimetry,which can potentially incubate various disruptive applications that depend on broadband polarization measurements.展开更多
Corrosion activities and related accidents are significant issues for marine facilities,leading to considerable economic losses.Waterborne epoxy(EP)coating has been seen as one of the optimal options for corrosion pro...Corrosion activities and related accidents are significant issues for marine facilities,leading to considerable economic losses.Waterborne epoxy(EP)coating has been seen as one of the optimal options for corrosion protection due to its stable properties and eco-friendliness(0 g/L volatile organic compounds).Nevertheless,several intrinsic deficiencies require improvement,such as fragile mechanical properties and defects(macro and micro),resulting in the continuous deterioration of comprehensive coating performances.In this work,a novel nanocomposite coating with mechanical enhancement,intelligent self-reporting,and active protection is fabricated by integrating the functionalized and compatible graphene oxide/cerium based metal-organic framework multiscale structure(GO-CeMOF-P/M).Notably,the homogenous dispersion of GO-CeMOF-P/M and its chemical interaction with the polymer matrix effectively reduces the defects resulting from solution volatilizing and enhances the compactness,which boosts the tensile strength(32.1 MPa/8.5%)and dry adhesion force(5.8 MPa)of the coating.Additionally,the controllable responsiveness and release of multiscale nanocomposite within external environments endow intelligent active protection and self-reporting characteristics for the GO-CeMOF-P/M-EP coating,making it especially suitable for a variety of practical marine applications.Furthermore,following immersion of 80 d in the aggressive environment,Zf=0.01 Hz value of GO-CeMOF-P/M-EP coating is 1.2×10^(10)Ωcm^(2),which is 164.4 times larger than that of EP coating(7.3×10^(7)Ωcm^(2)),demonstrating remarkably strengthened anti-corrosion ability.Consequently,by offering an intriguing design strategy,the current work anticipates addressing the inherent deficiencies of EP coating and facilitating its practicality and feasibility in real sea environments.展开更多
We report a spatially modulated polarimetry scheme by using a zero-order vortex half-wave retarder(ZVHR)and a spatial Fourier analysis method.A ZVHR is employed to analyze the input polarized light and convert it into...We report a spatially modulated polarimetry scheme by using a zero-order vortex half-wave retarder(ZVHR)and a spatial Fourier analysis method.A ZVHR is employed to analyze the input polarized light and convert it into a vectorial optical field,and an analyzer is set after the ZVHR to form an hourglass intensity pattern due to the spatial polarization modulation.Then,the input light’s Stokes parameters can be calculated by spatial Fourier analysis of the hourglass pattern with a single shot.The working principle of the polarimeter has been analyzed by the Stokes-Mueller formalism,and some quantitative measuring experiments of different polarization states have been demonstrated.The experimental results indicate that the proposed polarimeter is accurate,robust,and simple to use.展开更多
With the widespread prevailing of flexible electronics in human-machine interfaces,health monitor,and human motion detection,ultrasoft flexible sensors are urgently desired with critical demands in conformality.Herein...With the widespread prevailing of flexible electronics in human-machine interfaces,health monitor,and human motion detection,ultrasoft flexible sensors are urgently desired with critical demands in conformality.Herein,a temperature-sensitive ionogel with near-infrared(NIR)-light controlled adhesion is prepared by electrostatic interaction of poly(diallyl dimethylammonium chloride)(PDDA)and acrylic acid,as well as the incorporation of the conductive polydopamine modified polypyrrole nanoparticles(PPy-PDA NPs).The PPy-PDA NPs could weaken the tough interaction between polymer chains and depress the Young’s modulus of the ionogel,thus promoting the ionogel ultrasoft(34 kPa)and highly stretchable(1,013%)performance to tensile deformations.In addition,the high photothermal conversion capacity of PPy-PDA NPs ensured the ionogel excellent NIR-light controlled adhesion and temperature sensitivity,which facilitated the ionogel on-demand removal and promised a reliable thermal sensor.Moreover,the resulted ultrasoft flexible sensor exhibited high sensitivity and stability to both strain and pressure in a broad range of deformations,enabling a precise monitoring on various human motions and physiological activities.The temperature-sensitive,ultrasoft,and controlled adhesive capabilities prompted great potential of the flexible ionogel in medical diagnosis and wearable electronics.展开更多
An ultralow specific on-resistance high-k LDMOS with vertical field plate（VFP HK LDMOS） is proposed. The high-k dielectric trench and highly doped interface N＋ layer are made in bulk silicon to reduce the surface f...An ultralow specific on-resistance high-k LDMOS with vertical field plate（VFP HK LDMOS） is proposed. The high-k dielectric trench and highly doped interface N＋ layer are made in bulk silicon to reduce the surface field of the drift region in the VFP HK LDMOS. The gate vertical field plate（VFP） pinning in the high-k dielectric trench can modulate the bulk electric field. The high-k dielectric not only provides polarized charges to assist depletion of the drift region, so that the drift region and high-k trench maintain charge balance adaptively,but also can fully assist in depleting the drift region to increase the drift doping concentration and reshape the electric field to avoid premature breakdown. Compared with the conventional structure, the VFP HK LDMOS has the breakdown voltage of 629.1 V at the drift length of 40 μm and the specific on-resistance of 38.4 mΩ·cm^2 at the gate potential of 15 V. Then the power figure of merit is 10.31 MW/cm^2.展开更多
The power scaling on short wavelength(SW)fiber lasers operating around 1μm are in significant demand for applications in energy,environment and industry.The challenge for performance scalability of high-power SW lase...The power scaling on short wavelength(SW)fiber lasers operating around 1μm are in significant demand for applications in energy,environment and industry.The challenge for performance scalability of high-power SW lasers based on rare-earth-doped fiber primarily lies in the physical limitations,including reabsorption,amplified spontaneous emission and parasitic laser oscillation.Here,we demonstrate an all-fiberized,purely passive SW(1018 nm)randomdistributed-feedback Raman fiber laser(RRFL)to validate the capability of achieving high-power output at SWs based on multimode laser diodes(LDs)direct pumping.Directly pumped by multimode LDs,the high-brightness RRFL delivers over 656 W,with an electro-optical efficiency of 20%relative to the power.The slope efficiency is 94%.The beam quality M2factor is 2.9(which is~20 times that of the pump)at the maximum output signal power,achieving the highest brightness enhancement of 14.9 in RRFLs.To the best of our knowledge,this achievement also represents the highest power record of RRFLs utilizing multimode diodes for direct pumping.This work may not only provide a new insight into the realization of high-power,high-brightness RRFLs but also is a promising contender in the power scaling of SWs below 1μm.展开更多
The power scaling on mid-infrared Raman fibre lasers(RFLs) is in demand for applications in health, environment and security. In this paper, we present the simulated laser behaviours of the tellurite glass RFLs pumped...The power scaling on mid-infrared Raman fibre lasers(RFLs) is in demand for applications in health, environment and security. In this paper, we present the simulated laser behaviours of the tellurite glass RFLs pumped by 300-W Tm-doped fibre lasers(TDFLs) at 2 μm for the first time. By combining the advantages of the TDFLs and tellurite fibre, the output power at 2.35 μm has reached over hundreds of watts by first-order Raman shift. Moreover, the cascaded RFLs have been demonstrated with a wavelength extension greater than 3 μm and output power of tens of watts. To maximize the output power and the slope efficiency of the RFLs, we further analyse the interaction between the Raman gain and cavity loss, which are determined by fibre length and output reflectance of the laser cavity.展开更多
Sulfate-reducing bacteria(SRB)corrosion is one of the main reasons leading to the service failure of engineering materials in the marine environment.An understanding of SRB corrosion especially under continuous organi...Sulfate-reducing bacteria(SRB)corrosion is one of the main reasons leading to the service failure of engineering materials in the marine environment.An understanding of SRB corrosion especially under continuous organic carbon starvation is required.In this work,SRB corrosion of X80 pipeline steel under continuous organic carbon starvation was studied using mass loss,electrochemical measurements,and surface analysis.The effects of initial SRB concentrations on steel corrosion were also studied and discussed.The results indicated that more than 99%population of SRB die after 21 d of testing in various conditions,but there are still amounts of SRB survivors.SRB survivors with continued organic carbon starvation have a better adaptive ability and accelerated steel corrosion.Both the uniform and localized corrosion rates are also proportional to the initial SRB concentration as well as SRB survivors.The localized corrosion rate and density of corrosion pits of specimen corresponding to an initial SRB count of 10^(8) cells/m L reach bigger values of(0.693±0.114)mm/y and(1.94±0.39)×10^(4) pits/cm^(2),respectively,which are induced by the combination of the sessile and planktonic SRB.展开更多
Ni–Cu coatings were obtained through direct current electrodeposition in electroplating bath with ceric sulfate in varying concentration(0–1.2 g/L),respectively.Effects of ceric sulfate on microstructure and corrosi...Ni–Cu coatings were obtained through direct current electrodeposition in electroplating bath with ceric sulfate in varying concentration(0–1.2 g/L),respectively.Effects of ceric sulfate on microstructure and corrosion resistance of the coatings were analyzed through high-resolution transmission electron microscopy,potentiodynamic polarization,and localized electrochemical impedance spectroscopy.Semiconductor performance of a passive film formed on the Ni–Cu coatings was characterized by the Mott–Schottky measurements.Results demonstrated that Ce was co-deposited in the Ni–Cu coating obtained in the ceric sulfate containing electroplating bath.The trace addition of Ce distinctly improved corrosion resistance of the Ni–Cu coatings,which is ascribed to that the interfacial reactions between Ni–Cu coating and the passive film were suppressed by the reduction of the point defect diffusivity after the formation of a dense cerium oxide film.展开更多
To realize continuously and stably work in a“moist/hot environment”,flexible electronics with excellent humid resistance,antiswelling,and detection sensitivity are demanding.Herein,a solvent-resistant and temperatur...To realize continuously and stably work in a“moist/hot environment”,flexible electronics with excellent humid resistance,antiswelling,and detection sensitivity are demanding.Herein,a solvent-resistant and temperature-ultrasensitive hydrogel sensor was prepared by combining MXene and quaternized chitosan(QCS)with the binary polymer chain.The strong electrostatic interaction between the QCS chain and the poly(acrylic acid)(PAA)network endows the hydrogel stability against solvent erosion,high temperature,and high humidity.The strong dynamic interaction between MXene and polymer matrix significantly improves the mechanical properties and sensing(strain and temperature)sensitivity of the hydrogel.The hydrogel strain sensor exhibits a high gauge factor(5.53),temperature/humidity tolerance(equilibrium swelling ratio of 2.5%at 80℃),and excellent cycle stability,which could achieve a remote and accurate perception of complex human motion and environment fluctuation under aquatic conditions.Moreover,the hydrogel sensor exhibits impressive thermal response sensitivity(-3.183%/℃),ultrashort response time(<2.53 s),and a low detection limit(<0.5℃)in a wide temperature range,which is applied as an indicator of the body surface and ambient temperature.In short,this study broadens the application scenarios of hydrogels in persistent extreme thermal and wet environments.展开更多
基金financially supported by the National Natural Science Foundation of China (Nos. 51001108 and 51131007)the National Basic Research Program of China (No. 2010CB934604)
文摘An eco-friendly rust converter treatment based on tannic acid was optimized by orthogonal experiment, and the adhesion of the epoxy top-coating system was evaluated. The results showed that the adhesion between the epoxy coating and the rusted steel after treatment was enhanced from 1.93 to 5.97 MPa. This adhesion improvement was attributed to the formation of the micro-cracked tannic conversion layer and the increase of the compactness of the rust layer. The failure analysis suggested that the remainder rust was still the key issue for the further adhesion improvement of the coating system.
基金support from the National Key R&D Program of China(No.2019YFE0111000)the National Natural Science Foundation of China(Nos.52171093,51771061 and U20A20233).
文摘Chloride-induced corrosion of steel reinforcement is the key factor leading to the degradation of reinforced concrete building durability.Improving the corrosion resistance of oxide scale of rebar has always been a research hotspot in the field of civil engineering materials.A ZIF-8 modified Ce-Sol-gel(ZCS)film was prepared on oxide scale of plain steel rebars by sol-gel method.It is observed that the|Z|_(0.01 Hz)value of the ZCS film reached 320 kΩcm^(2),which is about 29 times higher than that of blank rebar in simulated concrete pore(SCP)solution with 0.1 M NaCl.Then,they were inserted into mortar block and curing them in a curing box at T=20±2℃and RH=95±2%for 28 days.Subsequently,these samples were subject to electrochemical impedance spectroscopy in 3.5 wt%NaCl.The|Z|_(0.01 Hz)value of the rebar with the ZCS film was six times higher than that of the blank rebar after immersing for 20 days,resulting in an overall increase in corrosion resistance for rebar.The results indicated that the modification by ZIF-8 could reduce the porosity of Ce-sol-gel(CS)film and improved the“labyrinth effect”of the film.Additionally,the negative charge on the surface of ZIF-8 in alkaline condition increased the repulsion effect with Cl−,significantly reducing the sensitivity of rebar to Cl−.
基金This research was financially supported by the National Key Re-search and Development Program of China(No.2019YFE0111000)the National Natural Science Foundation of China(Nos.51903257,U20A20233 and U22A20135)+1 种基金the Natural Science Founda-tion of Guangdong Province of China(Nos.2023A1515012275,2022A1515010805)The authors thank Zhuhai Leitong Laser Tech-nology Co.Ltd.for preparing the defect coating by laser cutter.
文摘Organic coatings are commonly used to protect the metals or alloys from corrosion.However,defects such as scratches or natural aging of the coating can induce unexpected diffusion paths for the corrosive media,so the wettability of repairing liquids and the selection of suitable repairing liquids are crucial.In this study,we systematically investigated the capillary impregnation phenomenon by using liquids with various surface tensions and glass capillaries with different surface energies.We utilized this regularity to instruct the defects repairing process.By using an ultra-depth field microscope,scanning electron mi-croscope,and electrochemical analysis,two kinds of repairing liquids,high surface tension liquid(HSTL)and low surface tension liquid(LSTL),were investigated for repairing man-made defects of coatings.Our results showed that the substrate and the surface energy of the liquids significantly influence the infil-tration of the repair liquid.By effectively leveraging the relationship between the repair liquid and the substrate,the repair agent can not only establish a uniform and dense repairing layer but also notably enhance the corrosion resistance of the defective coating.This study provides valuable insights into the repairing of coating defects,as well as liquids transportation,microfluidic chip design,and surface modi-fication of microporous materials.
基金financial support from the National Natural Science Foundation of China(Nos.52171093,51771061,and U20A20233)the National Key R&D Program of China(No.2019YFE0111000).
文摘In this study,basalt scales were activated by air plasma and were subsequently deposited with cerium dioxide nanoparticles to obtain CeO_(2)-modified basalts(CB).Inspired by mussel biomimetics,polydopamine(PDA)and 3-glycidoxypropyltrimethoxysilane were further employed to modify the properties of CB to obtain functionalized basalt scales(CBD).This treatment greatly increased the interfacial compatibility between inorganic fillers and epoxy resin.At the same time,PDA can form chelates with iron ions in the anodic area to prevent further corrosion.Tensile,water absorption,and electrochemical impedance spectrum measurements showed that incorporating CBD into epoxy resins resulted in the composite coatings with higher mechanical properties,water penetration resistance,corrosion resistance,and lower wetting properties.
文摘BACKGROUND Chronic granulomatous disease(CGD)characterized by recurrent and severe bacterial and fungal infections is most common in childhood.CASE SUMMARY We reported a 24-d-old male infant who developed gastrointestinal symptoms as the first sign of CGD.CONCLUSION Gastrointestinal symptoms representing the first sign of CGD are very rare,and prompt diagnosis and treatment with broad-spectrum antibiotics were of crucial importance.
基金National Natural Science Foundation of China(62475285,61975235)Natural Science Foundation of Hunan Province(2019JJ40342)。
文摘Broadband polarization measurement plays a crucial role in numerous fields,spanning from fundamental physics to a wide range of practical applications.However,traditional approaches typically rely on combinations of various dispersive optical elements,requiring bulky systems and complicated time-consuming multiple procedures.Here we have achieved broadband spectropolarimetry based on single-shot images for spatial intensity distributions of polychromatic vector beams.A custom-designed diffractive optical element and a vortex retarder convert the incident polychromatic waves into structured vector beams:the former diffracts light of different wavelengths into concentric circles of different radii,while the latter codes their polarization information into intensity distributions along the azimuthal direction.The validation experiments verify our exceptional measurement accuracy(RMS errors<1%)for each Stokes component in the visible light range(400-700 nm),with good spectral(<0.8 nm)and temporal(an output rate of 100 Hz)resolutions.We have further employed our broadband polarimeter to study the mutarotation of glucose,making direct observations of temporal evolutions of chemical reactions accessible.Our work has significantly broadened the toolboxes of spectropolarimetry,which can potentially incubate various disruptive applications that depend on broadband polarization measurements.
基金financially supported by the National Natural Science Foundation of China(Nos.52371088,52071347,and U20A20233)Guangdong Basic and Applied Basic Research Foundation(No.2023A1515240007)Shenzhen Science and Technology Program(No.KJZD20230923114819041).
文摘Corrosion activities and related accidents are significant issues for marine facilities,leading to considerable economic losses.Waterborne epoxy(EP)coating has been seen as one of the optimal options for corrosion protection due to its stable properties and eco-friendliness(0 g/L volatile organic compounds).Nevertheless,several intrinsic deficiencies require improvement,such as fragile mechanical properties and defects(macro and micro),resulting in the continuous deterioration of comprehensive coating performances.In this work,a novel nanocomposite coating with mechanical enhancement,intelligent self-reporting,and active protection is fabricated by integrating the functionalized and compatible graphene oxide/cerium based metal-organic framework multiscale structure(GO-CeMOF-P/M).Notably,the homogenous dispersion of GO-CeMOF-P/M and its chemical interaction with the polymer matrix effectively reduces the defects resulting from solution volatilizing and enhances the compactness,which boosts the tensile strength(32.1 MPa/8.5%)and dry adhesion force(5.8 MPa)of the coating.Additionally,the controllable responsiveness and release of multiscale nanocomposite within external environments endow intelligent active protection and self-reporting characteristics for the GO-CeMOF-P/M-EP coating,making it especially suitable for a variety of practical marine applications.Furthermore,following immersion of 80 d in the aggressive environment,Zf=0.01 Hz value of GO-CeMOF-P/M-EP coating is 1.2×10^(10)Ωcm^(2),which is 164.4 times larger than that of EP coating(7.3×10^(7)Ωcm^(2)),demonstrating remarkably strengthened anti-corrosion ability.Consequently,by offering an intriguing design strategy,the current work anticipates addressing the inherent deficiencies of EP coating and facilitating its practicality and feasibility in real sea environments.
基金supported by the National Natural Science Foundation of China(NSFC)(No.61975235)the Natural Science Foundation of Hunan Province(No.2019JJ40342)。
文摘We report a spatially modulated polarimetry scheme by using a zero-order vortex half-wave retarder(ZVHR)and a spatial Fourier analysis method.A ZVHR is employed to analyze the input polarized light and convert it into a vectorial optical field,and an analyzer is set after the ZVHR to form an hourglass intensity pattern due to the spatial polarization modulation.Then,the input light’s Stokes parameters can be calculated by spatial Fourier analysis of the hourglass pattern with a single shot.The working principle of the polarimeter has been analyzed by the Stokes-Mueller formalism,and some quantitative measuring experiments of different polarization states have been demonstrated.The experimental results indicate that the proposed polarimeter is accurate,robust,and simple to use.
基金supported by the National Key Research and Development Program of China(No.2020YFA0709900),the National Natural Science Foundation of China(No.61775089)the Natural Science Foundation of Shandong Province(No.ZR2020KB018)“Taishan scholars”construction special fund of Shandong Province.
文摘With the widespread prevailing of flexible electronics in human-machine interfaces,health monitor,and human motion detection,ultrasoft flexible sensors are urgently desired with critical demands in conformality.Herein,a temperature-sensitive ionogel with near-infrared(NIR)-light controlled adhesion is prepared by electrostatic interaction of poly(diallyl dimethylammonium chloride)(PDDA)and acrylic acid,as well as the incorporation of the conductive polydopamine modified polypyrrole nanoparticles(PPy-PDA NPs).The PPy-PDA NPs could weaken the tough interaction between polymer chains and depress the Young’s modulus of the ionogel,thus promoting the ionogel ultrasoft(34 kPa)and highly stretchable(1,013%)performance to tensile deformations.In addition,the high photothermal conversion capacity of PPy-PDA NPs ensured the ionogel excellent NIR-light controlled adhesion and temperature sensitivity,which facilitated the ionogel on-demand removal and promised a reliable thermal sensor.Moreover,the resulted ultrasoft flexible sensor exhibited high sensitivity and stability to both strain and pressure in a broad range of deformations,enabling a precise monitoring on various human motions and physiological activities.The temperature-sensitive,ultrasoft,and controlled adhesive capabilities prompted great potential of the flexible ionogel in medical diagnosis and wearable electronics.
基金Project supported by the National Natural Science Foundtion of China(No.61404011)the Research and Innovation Project of Graduate Students of Changsha University of Science&Technology(No.CX2017SS25)+1 种基金the Scientific Research Fund of Hunan Provincial Education Department(No.15C0034)the Introduction of Talents Project of Changsha University of Science Technology(No.1198023)
文摘An ultralow specific on-resistance high-k LDMOS with vertical field plate（VFP HK LDMOS） is proposed. The high-k dielectric trench and highly doped interface N＋ layer are made in bulk silicon to reduce the surface field of the drift region in the VFP HK LDMOS. The gate vertical field plate（VFP） pinning in the high-k dielectric trench can modulate the bulk electric field. The high-k dielectric not only provides polarized charges to assist depletion of the drift region, so that the drift region and high-k trench maintain charge balance adaptively,but also can fully assist in depleting the drift region to increase the drift doping concentration and reshape the electric field to avoid premature breakdown. Compared with the conventional structure, the VFP HK LDMOS has the breakdown voltage of 629.1 V at the drift length of 40 μm and the specific on-resistance of 38.4 mΩ·cm^2 at the gate potential of 15 V. Then the power figure of merit is 10.31 MW/cm^2.
基金supported by the National Natural Science Foundation of China(Nos.62061136013 and 12174445)。
文摘The power scaling on short wavelength(SW)fiber lasers operating around 1μm are in significant demand for applications in energy,environment and industry.The challenge for performance scalability of high-power SW lasers based on rare-earth-doped fiber primarily lies in the physical limitations,including reabsorption,amplified spontaneous emission and parasitic laser oscillation.Here,we demonstrate an all-fiberized,purely passive SW(1018 nm)randomdistributed-feedback Raman fiber laser(RRFL)to validate the capability of achieving high-power output at SWs based on multimode laser diodes(LDs)direct pumping.Directly pumped by multimode LDs,the high-brightness RRFL delivers over 656 W,with an electro-optical efficiency of 20%relative to the power.The slope efficiency is 94%.The beam quality M2factor is 2.9(which is~20 times that of the pump)at the maximum output signal power,achieving the highest brightness enhancement of 14.9 in RRFLs.To the best of our knowledge,this achievement also represents the highest power record of RRFLs utilizing multimode diodes for direct pumping.This work may not only provide a new insight into the realization of high-power,high-brightness RRFLs but also is a promising contender in the power scaling of SWs below 1μm.
基金the China Postdoctoral Science Foundation(No.2016M603003)State Key Laboratory of Luminescent Materials and Devices from South China University of Technology(No.2017-skllmd-09)
文摘The power scaling on mid-infrared Raman fibre lasers(RFLs) is in demand for applications in health, environment and security. In this paper, we present the simulated laser behaviours of the tellurite glass RFLs pumped by 300-W Tm-doped fibre lasers(TDFLs) at 2 μm for the first time. By combining the advantages of the TDFLs and tellurite fibre, the output power at 2.35 μm has reached over hundreds of watts by first-order Raman shift. Moreover, the cascaded RFLs have been demonstrated with a wavelength extension greater than 3 μm and output power of tens of watts. To maximize the output power and the slope efficiency of the RFLs, we further analyse the interaction between the Raman gain and cavity loss, which are determined by fibre length and output reflectance of the laser cavity.
基金financially supported by the National Natural Science Foundation of China(Nos.51901253 and 52271083)the Fundamental Research Funds for the Central Universities(Nos.19lgzd18 and 22qntd0801)+3 种基金the Guangdong Basic and Applied Basic Research Foundation(No.2019A1515011135)the Open Project Program of Beijing Key Laboratory of Pipeline Critical Technology and Equipment for Deepwater Oil&Gas Development(No.BIPT201904)the Open Project Program of Hubei Key Laboratory of Materials Chemistry and Service Failure(No.2020MCF02)the Shanghai Engineering Technology Research Centre of Deep Offshore Material(No.19DZ2253100)
文摘Sulfate-reducing bacteria(SRB)corrosion is one of the main reasons leading to the service failure of engineering materials in the marine environment.An understanding of SRB corrosion especially under continuous organic carbon starvation is required.In this work,SRB corrosion of X80 pipeline steel under continuous organic carbon starvation was studied using mass loss,electrochemical measurements,and surface analysis.The effects of initial SRB concentrations on steel corrosion were also studied and discussed.The results indicated that more than 99%population of SRB die after 21 d of testing in various conditions,but there are still amounts of SRB survivors.SRB survivors with continued organic carbon starvation have a better adaptive ability and accelerated steel corrosion.Both the uniform and localized corrosion rates are also proportional to the initial SRB concentration as well as SRB survivors.The localized corrosion rate and density of corrosion pits of specimen corresponding to an initial SRB count of 10^(8) cells/m L reach bigger values of(0.693±0.114)mm/y and(1.94±0.39)×10^(4) pits/cm^(2),respectively,which are induced by the combination of the sessile and planktonic SRB.
基金the financial supports from the National Key R&D Program of China(No.2019YFE0111000)the National Natural Science Foundation of China(Nos.51771061,51971073 and U20A20233)
文摘Ni–Cu coatings were obtained through direct current electrodeposition in electroplating bath with ceric sulfate in varying concentration(0–1.2 g/L),respectively.Effects of ceric sulfate on microstructure and corrosion resistance of the coatings were analyzed through high-resolution transmission electron microscopy,potentiodynamic polarization,and localized electrochemical impedance spectroscopy.Semiconductor performance of a passive film formed on the Ni–Cu coatings was characterized by the Mott–Schottky measurements.Results demonstrated that Ce was co-deposited in the Ni–Cu coating obtained in the ceric sulfate containing electroplating bath.The trace addition of Ce distinctly improved corrosion resistance of the Ni–Cu coatings,which is ascribed to that the interfacial reactions between Ni–Cu coating and the passive film were suppressed by the reduction of the point defect diffusivity after the formation of a dense cerium oxide film.
基金The work was supported by the National Key R&D Program of China(No.2020YFA0709900)“Taishan scholars”construction special fund of Shandong Province。
文摘To realize continuously and stably work in a“moist/hot environment”,flexible electronics with excellent humid resistance,antiswelling,and detection sensitivity are demanding.Herein,a solvent-resistant and temperature-ultrasensitive hydrogel sensor was prepared by combining MXene and quaternized chitosan(QCS)with the binary polymer chain.The strong electrostatic interaction between the QCS chain and the poly(acrylic acid)(PAA)network endows the hydrogel stability against solvent erosion,high temperature,and high humidity.The strong dynamic interaction between MXene and polymer matrix significantly improves the mechanical properties and sensing(strain and temperature)sensitivity of the hydrogel.The hydrogel strain sensor exhibits a high gauge factor(5.53),temperature/humidity tolerance(equilibrium swelling ratio of 2.5%at 80℃),and excellent cycle stability,which could achieve a remote and accurate perception of complex human motion and environment fluctuation under aquatic conditions.Moreover,the hydrogel sensor exhibits impressive thermal response sensitivity(-3.183%/℃),ultrashort response time(<2.53 s),and a low detection limit(<0.5℃)in a wide temperature range,which is applied as an indicator of the body surface and ambient temperature.In short,this study broadens the application scenarios of hydrogels in persistent extreme thermal and wet environments.
