This work uses refined first-order shear theory to analyze the free vibration and transient responses of double-curved sandwich two-layer shells made of auxetic honeycomb core and laminated three-phase polymer/GNP/fib...This work uses refined first-order shear theory to analyze the free vibration and transient responses of double-curved sandwich two-layer shells made of auxetic honeycomb core and laminated three-phase polymer/GNP/fiber surface subjected to the blast load.Each of the two layers that make up the double-curved shell structure is made up of an auxetic honeycomb core and two laminated sheets of three-phase polymer/GNP/fiber.The exterior is supported by a Kerr elastic foundation with three characteristics.The key innovation of the proposed theory is that the transverse shear stresses are zero at two free surfaces of each layer.In contrast to previous first-order shear deformation theories,no shear correction factor is required.Navier's exact solution was used to treat the double-curved shell problem with a single title boundary,while the finite element technique and an eight-node quadrilateral were used to address the other boundary requirements.To ensure the accuracy of these results,a thorough comparison technique is employed in conjunction with credible statements.The problem model's edge cases allow for this kind of analysis.The study's findings may be used in the post-construction evaluation of military and civil works structures for their ability to sustain explosive loads.In addition,this is also an important basis for the calculation and design of shell structures made of smart materials when subjected to shock waves or explosive loads.展开更多
Silica fibers were modified by a specific ratio of SiB6 mixed with silica sol through vacuum impregnation method.The modified fibers were then incorporated into a phenolic resin matrix to prepare fiber-reinforced resi...Silica fibers were modified by a specific ratio of SiB6 mixed with silica sol through vacuum impregnation method.The modified fibers were then incorporated into a phenolic resin matrix to prepare fiber-reinforced resin composites.The influences of the SiB_(6)/SiO_(2)mixed modification on silica fiber properties were analyzed through thermogravimetric analysis(TGA),differential scanning calorimetry(DSC),scanning electron microscopy(SEM),and X-ray diffraction(XRD),respectively.Additionally,the influence of the SiB_(6)/SiO_(2)mixed modification on the mechanical properties of phenolic resin matrix composites was evaluated through mechanical testing.The experimeatal results indicate that the SiB_(6)/SiO_(2)mixed surface modification shows significant improvement in strength at room temperature and high temperatures,and crystallization temperature of silica fiber increases.The SiB_(6)/Silica sol co-modified silica fiber shows potential for future application in thermal protection and other high-temperature conditions.展开更多
Polyacrylonitrile （PAN） based carbon fibers with different surface morphology were electrochemically treated in 3 wt% NH4HCO3 aqueous solution with current density up to 3.47 A/m 2 at room temperature, and surface s...Polyacrylonitrile （PAN） based carbon fibers with different surface morphology were electrochemically treated in 3 wt% NH4HCO3 aqueous solution with current density up to 3.47 A/m 2 at room temperature, and surface structures, surface morphology and residual mechanical properties were characterized. The crystallite size （La） of carbon fibers would be interrupted due to excessive electrochemical etching, while the crystallite spacing （d（002）） increased as increasing current density. The disordered structures on the surface of carbon fiber with rough surface increased at the initial oxidation stage and then removed by further electrochemical etching, which resulting in continuous increase of the extent of graphitization on the fiber surface. However, the electrochemical etching was beneficial to getting ordered morphology on the surface for carbon fiber with smooth surface, especially when the current density was lower than 1.77 A/m 2 . The tensile strength and tensile modulus could be improved by 17.27% and 5.75%, respectively, and was dependent of surface morphology. The decreasing density of carbon fibers probably resulted from the volume expansion of carbon fibers caused by the abundant oxygen functional groups intercalated between the adjacent graphite layers.展开更多
Glucose is an indispensable nutrient for metabolism in living organisms and is widely used in food,industry,and medical fields.Glucose is often added as a sweetener in food and often used in industry as a reducing age...Glucose is an indispensable nutrient for metabolism in living organisms and is widely used in food,industry,and medical fields.Glucose is often added as a sweetener in food and often used in industry as a reducing agent for various products.In medical treatment,glucose is added to many drugs as a nutritional additive,and it is also an indicator that diabetics need to pay attention to at all time.Therefore,the market has a great demand for low-cost,high-sensitivity,fast,and convenient glucose sensors,and the industry has always attached great importance to the work of creating new glucose sensor devices.Therefore,we proposed a SnO_(2)nanofibers/Au structure multimode-single-mode-multimode(MSM)fiber surface plasmon resonance(SPR)glucose sensor.SnO_(2)nanofibers were fixed to a single-mode fiber core that had been plated with the Au film by electrospinning.When the glucose concentration increased at 5 vol%intervals,the corresponding resonance wavelengths had different degrees of redshifts.Comparing the two structures,as the glucose concentration range increased from 0 vol%to 60 vol%,the sensitivity increased from 228.7 nm/vol%in the Au structure to 337.3 nm/vol%in the SnO_(2)nanofiber/Au structure.At the same time,the linear correlation between the resonant wavelength and the refractive index of the two structures was greater than 0.98.Moreover,the SnO_(2)nanofibers/Au structure significantly improved the practical application performance of SPR sensors.展开更多
A silane containing isocynate groups（3-（trimethoxysilyl） propyl cyanic acid ester,NCO） associated with hexamethyldisilazane（HDMS） is used to modify the surface of poly-（p-phenylene terephthalamide）（PPTA） pul...A silane containing isocynate groups（3-（trimethoxysilyl） propyl cyanic acid ester,NCO） associated with hexamethyldisilazane（HDMS） is used to modify the surface of poly-（p-phenylene terephthalamide）（PPTA） pulps. As concerns surface chemistry,Attenuated Total Reflection Flourier Transformed Infrared Spectroscopy（ATR FT-IR） and X-ray photoelectron spectroscopy（XPS） confirm that NCO associated with HDMS silylated PPTA pulp surface successfully. While the modified PPTA pulps are used as reinforcing fillers for silicone composites,the dispersibility and storage stability of the composites are improved as Mooney testing indicated. The silicone composites filled with modified PPTA pulps present a higher tensile strength and much higher broken elongation（3.30 MPa and 166.54%） than that with unmodified pulps（3.08 MPa and 68.47%）,respectively.展开更多
Herein, we report a simple and effective preparation of ultrafine CNFs （u-CNFs） with high surface area via electrospinning of two immiscible polymers [polyacrylonitrile （PAN） and poly（methyl methacry- late） （P...Herein, we report a simple and effective preparation of ultrafine CNFs （u-CNFs） with high surface area via electrospinning of two immiscible polymers [polyacrylonitrile （PAN） and poly（methyl methacry- late） （PMMA）] followed by calcination at high temperature in an inert atmosphere. Various electrospinning conditions were optimized in detail. Four different kinds of PAN/PMMA ratios （10/0, 7：3, 5：5 and 3：7） were chosen and found that the PAN/PMMA ratio of 3：7 （PAN/PMMA-3：7） is the optimum one. BET anal- ysis showed the specific surface area of the u-CNFs-3：7 was 46Z57 m2/g with an excellent pore volume （1.15 cms g-l） and an average pore size （9.48 nm）： it is about 25 times higher than the conventional CNFs （c-CNFs）. TEM and FE-SEM images confirmed the ultrafine structure of the CNFs with a thinner fiber di- ameter of-50 nm. The graphitic nature and atomic arrangement of the u-CNFs were investigated by Raman and XPS analyses. For the supercapacitor application, unlike the common electrode preparation methods, the u-CNFs-3：7 was used without any activation, chemical or mechanical modifications. The u-CNFs- 3：7 showed a better specific capacitance of 86 Fig in 1 mol/L 1-12S04 when compared to pure CNFs. The excellent physicochemical properties make the u-CNFs-3：7 an alternative choice to the existing CNFs for the supercapacitors.展开更多
We report about current work which is aimed to improve the adhesion of melt processable elastomers onto relevant reinforcement materials by means of short wave UVC （ultraviolet C） light. Results of laboratory tests ...We report about current work which is aimed to improve the adhesion of melt processable elastomers onto relevant reinforcement materials by means of short wave UVC （ultraviolet C） light. Results of laboratory tests regarding UVC surface activation ofpolyamide fiber materials in air using low-pressure mercury lamps with 185 nm and 254 nm emissions are shown. The effect of irradiation on fiber strength was studied to find out suitable process parameters for providing the UVC treatment efficient but as gentle as possible to avoid negative effects on reinforcement properties. Application of a laboratory process for UVC pretreatment leads to significantly increased adhesion strength between the fibers and the melt processable elastomers on the base of TPA （polyamide） respectively TPU （polyurethane）.展开更多
In this paper, a long line-shape dielectric barrier discharge excited by a nanosecond pulse and AC is generated in atmospheric air for the purpose of discussing the uniformity, stability and ability of aramid fiber tr...In this paper, a long line-shape dielectric barrier discharge excited by a nanosecond pulse and AC is generated in atmospheric air for the purpose of discussing the uniformity, stability and ability of aramid fiber treatment. The discharge images, waveforms of current and voltage,optical emission spectra, and gas temperatures of both discharges are compared. It is found that nanosecond pulsed discharge has a more uniform discharge morphology, higher energy efficiency and lower gas temperature, which indicates that nanosecond pulsed discharge is more suitable for surface modification. To reduce the water contact angle from 96° to about 60°, the energy cost is only about 1/7 compared with AC discharge. Scanning electron microscopy,Fourier transform infrared spectroscopy and x-ray photoelectron spectroscopy are employed to understand the mechanisms of hydrophilicity improvement.展开更多
Porous polypropylene hollow fiber(PPHF) membranes are widely used in liquid purification. However, the hydrophobicity of polypropylene(PP) has limited its applications in water treatment. Herein, we demonstrate that, ...Porous polypropylene hollow fiber(PPHF) membranes are widely used in liquid purification. However, the hydrophobicity of polypropylene(PP) has limited its applications in water treatment. Herein, we demonstrate that, for the first time, atomic layer deposition(ALD) is an effective strategy to conveniently upgrade the filtration performances of PPHF membranes. The chemical and morphological changes of the deposited PPHF membranes are characterized by spectral, compositional, microscopic characterizations and protein adsorption measurements. Al_2O_3 is distributed along the cross section of the PP hollow fibers, with decreasing concentration from the outer surface to the inner surface. The pore size of the outer surface can be easily turned by altering the ALD cycles. Interestingly, the hollow fibers become much more ductile after deposition as their elongation at break is increased more than six times after deposition with 100 cycles. The deposited membranes show simultaneously enhanced water permeance and retention after deposition with moderate ALD cycle numbers.For instance, after 50 ALD cycles a 17% increase in water permeance and one-fold increase in BSA rejection are observed. Moreover, the PP membranes exhibit improved fouling-resistance after ALD deposition.展开更多
Structure modulation at multiscale is crucialfor optimizing the electromagnetic wave absorption (EWA)properties of fiber-reinforced composites. Here we selectedtwo types of wave-absorbing SiC fibers as reinforcements....Structure modulation at multiscale is crucialfor optimizing the electromagnetic wave absorption (EWA)properties of fiber-reinforced composites. Here we selectedtwo types of wave-absorbing SiC fibers as reinforcements. TheL-fiber had a relatively low resistivity of ~3 Ω·cm and the Hfiberhad a high resistivity of ~7×10^(5)Ω·cm. To adjust the impedance,BN single coating and SiO_(2)/BN dual-coating wereprepared respectively on the L-fibers. Unidirectional prepregswith different fibers were stacked in different rules to obtainthe final composites. It showed that both the fiber coatings andstacking structure significantly influence the EWA performanceof the composites. Guided by computational optimization,the stacked composites exhibited superior reflectionloss (RL) lower than −10 dB across the whole X(8.2–12.4 GHz) and Ku (12.4–18.0 GHz) bands. It is interestingto find that the introduction of the surface coatings on theL-fibers significantly widens the available thickness range ofthe stacked composite for possessing excellent performance. Inparticular, dual-coating perform better in terms of broadeningthe available thickness range of the stacked composites.展开更多
The ultralow limit of detection(LoD)and exceptional sensitivity of biosensors are a significant challenge currently faced in the field.To address this challenge,this work proposes a highly sensitive laser ring cavity ...The ultralow limit of detection(LoD)and exceptional sensitivity of biosensors are a significant challenge currently faced in the field.To address this challenge,this work proposes a highly sensitive laser ring cavity biosensor capable of detecting low concentrations of des-γ-carboxy prothrombin(DCP).A tapered W-shaped fiber probe based on multi-mode fiber(MMF)-multi-core fiber(MCF)-MMF is developed to excite strong evanescent waves(EWs).By immobilizing gold nanorods(GNRs)on the fiber probe,localized surface plasmon resonance(LSPR)is generated at the near infrared wavelength to further enhance the sensitivity of the fiber probe.Moreover,an erbium-doped fiber(EDF)ring laser with a narrow full width at half maximum(FWHM)of 0.11 nm is employed as a light source.The spectrum with narrow FWHM has been demonstrated to obtain lower Lo D.Compared to the ASE light source,the Lo D of the laser ring cavity can be reduced by an order of magnitude.The developed biosensor is capable of detecting DCP within a concentration range of 0-1000 ng/mL,and the detection sensitivity of 0.265 nm/lg(ng/mL)and the Lo D of 367.6 pg/m L are obtained.In addition,the proposed laser ring cavity biosensor demonstrates good specificity,reproducibility,and repeatability by corresponding tests.The study results indicate that the proposed biosensor has potential in the detection of hepatocellular carcinoma markers.展开更多
A high sensitivity D-shaped hole double-cladding fiber temperature sensor based on surface plasmon resonance(SPR)is designed and investigated by a full-vector finite element method.Within the D-shaped hole doublecladd...A high sensitivity D-shaped hole double-cladding fiber temperature sensor based on surface plasmon resonance(SPR)is designed and investigated by a full-vector finite element method.Within the D-shaped hole doublecladding fiber,the hollow D-section is coated with gold film and then injected in a high thermo-optic coefficient liquid to realize the high temperature sensitivity for the fiber SPR temperature sensor.The numerical simulation results show that the peaking loss of the D-shaped hole double-cladding fiber SPR is hugely influenced by the distance between the D-shaped hole and fiber core and by the thickness of the gold film,but the temperature sensitivity is almost insensitive to the above parameters.When the thermo-optic coefficient is -2.8×10^(-4)∕℃,the thickness of the gold film is 47 nm,and the distance between the D-shaped hole and fiber core is 5μm,the temperature sensitivity of the D-shaped hole fiber SPR sensor can reach to -3.635 nm∕℃.展开更多
Reflective fiber optic sensors have advantages for surface roughness measurements of some special workpieces,but their measuring precision and efficiency need to be improved further. A least-squares support vector mac...Reflective fiber optic sensors have advantages for surface roughness measurements of some special workpieces,but their measuring precision and efficiency need to be improved further. A least-squares support vector machine（LS-SVM）-based surface roughness prediction model is proposed to estimate the surface roughness, Ra, and the coupled simulated annealing（CSA） and standard simplex（SS） methods are combined for the parameter optimization of the mode. Experiments are conducted to test the performance of the proposed model, and the results show that the range of average relative errors is-4.232%–2.5709%. In comparison with the existing models, the LS-SVM-based model has the best performance in prediction precision, stability, and timesaving.展开更多
An optical fiber sensor for ultrathin layer sensing based o51 short-range surface plasmon polariton （SRSPP） is proposed, and the sensing characteristics are theoretically analyzed. Simulation results indicate that e...An optical fiber sensor for ultrathin layer sensing based o51 short-range surface plasmon polariton （SRSPP） is proposed, and the sensing characteristics are theoretically analyzed. Simulation results indicate that even for a detecting layer much thinner than the vacuum wavelength, a resolution as high as 3.7×10-6 RIU can be obtained. Moreover, an average ttfickness-detection sensitivity of 6.2 dB/nm is obtained, which enables the sensor to detect the thickness variation of the ultrathin layer up to tens of nanometers. The sensitive region of thickness could be adjusted by tuning the structure parameters.展开更多
文摘This work uses refined first-order shear theory to analyze the free vibration and transient responses of double-curved sandwich two-layer shells made of auxetic honeycomb core and laminated three-phase polymer/GNP/fiber surface subjected to the blast load.Each of the two layers that make up the double-curved shell structure is made up of an auxetic honeycomb core and two laminated sheets of three-phase polymer/GNP/fiber.The exterior is supported by a Kerr elastic foundation with three characteristics.The key innovation of the proposed theory is that the transverse shear stresses are zero at two free surfaces of each layer.In contrast to previous first-order shear deformation theories,no shear correction factor is required.Navier's exact solution was used to treat the double-curved shell problem with a single title boundary,while the finite element technique and an eight-node quadrilateral were used to address the other boundary requirements.To ensure the accuracy of these results,a thorough comparison technique is employed in conjunction with credible statements.The problem model's edge cases allow for this kind of analysis.The study's findings may be used in the post-construction evaluation of military and civil works structures for their ability to sustain explosive loads.In addition,this is also an important basis for the calculation and design of shell structures made of smart materials when subjected to shock waves or explosive loads.
基金Funded by the Natural Science Foundation of Hubei Province(No.2024AFB833)。
文摘Silica fibers were modified by a specific ratio of SiB6 mixed with silica sol through vacuum impregnation method.The modified fibers were then incorporated into a phenolic resin matrix to prepare fiber-reinforced resin composites.The influences of the SiB_(6)/SiO_(2)mixed modification on silica fiber properties were analyzed through thermogravimetric analysis(TGA),differential scanning calorimetry(DSC),scanning electron microscopy(SEM),and X-ray diffraction(XRD),respectively.Additionally,the influence of the SiB_(6)/SiO_(2)mixed modification on the mechanical properties of phenolic resin matrix composites was evaluated through mechanical testing.The experimeatal results indicate that the SiB_(6)/SiO_(2)mixed surface modification shows significant improvement in strength at room temperature and high temperatures,and crystallization temperature of silica fiber increases.The SiB_(6)/Silica sol co-modified silica fiber shows potential for future application in thermal protection and other high-temperature conditions.
基金supported by the National Basic Research Program of China (No. 2011CB605602)
文摘Polyacrylonitrile （PAN） based carbon fibers with different surface morphology were electrochemically treated in 3 wt% NH4HCO3 aqueous solution with current density up to 3.47 A/m 2 at room temperature, and surface structures, surface morphology and residual mechanical properties were characterized. The crystallite size （La） of carbon fibers would be interrupted due to excessive electrochemical etching, while the crystallite spacing （d（002）） increased as increasing current density. The disordered structures on the surface of carbon fiber with rough surface increased at the initial oxidation stage and then removed by further electrochemical etching, which resulting in continuous increase of the extent of graphitization on the fiber surface. However, the electrochemical etching was beneficial to getting ordered morphology on the surface for carbon fiber with smooth surface, especially when the current density was lower than 1.77 A/m 2 . The tensile strength and tensile modulus could be improved by 17.27% and 5.75%, respectively, and was dependent of surface morphology. The decreasing density of carbon fibers probably resulted from the volume expansion of carbon fibers caused by the abundant oxygen functional groups intercalated between the adjacent graphite layers.
基金support from the Natural Science Foundation of Liaoning Province,China(Grant No.2021-MS-082).
文摘Glucose is an indispensable nutrient for metabolism in living organisms and is widely used in food,industry,and medical fields.Glucose is often added as a sweetener in food and often used in industry as a reducing agent for various products.In medical treatment,glucose is added to many drugs as a nutritional additive,and it is also an indicator that diabetics need to pay attention to at all time.Therefore,the market has a great demand for low-cost,high-sensitivity,fast,and convenient glucose sensors,and the industry has always attached great importance to the work of creating new glucose sensor devices.Therefore,we proposed a SnO_(2)nanofibers/Au structure multimode-single-mode-multimode(MSM)fiber surface plasmon resonance(SPR)glucose sensor.SnO_(2)nanofibers were fixed to a single-mode fiber core that had been plated with the Au film by electrospinning.When the glucose concentration increased at 5 vol%intervals,the corresponding resonance wavelengths had different degrees of redshifts.Comparing the two structures,as the glucose concentration range increased from 0 vol%to 60 vol%,the sensitivity increased from 228.7 nm/vol%in the Au structure to 337.3 nm/vol%in the SnO_(2)nanofiber/Au structure.At the same time,the linear correlation between the resonant wavelength and the refractive index of the two structures was greater than 0.98.Moreover,the SnO_(2)nanofibers/Au structure significantly improved the practical application performance of SPR sensors.
文摘A silane containing isocynate groups（3-（trimethoxysilyl） propyl cyanic acid ester,NCO） associated with hexamethyldisilazane（HDMS） is used to modify the surface of poly-（p-phenylene terephthalamide）（PPTA） pulps. As concerns surface chemistry,Attenuated Total Reflection Flourier Transformed Infrared Spectroscopy（ATR FT-IR） and X-ray photoelectron spectroscopy（XPS） confirm that NCO associated with HDMS silylated PPTA pulp surface successfully. While the modified PPTA pulps are used as reinforcing fillers for silicone composites,the dispersibility and storage stability of the composites are improved as Mooney testing indicated. The silicone composites filled with modified PPTA pulps present a higher tensile strength and much higher broken elongation（3.30 MPa and 166.54%） than that with unmodified pulps（3.08 MPa and 68.47%）,respectively.
基金supported by a research fund of Chungnam National University in 2014
文摘Herein, we report a simple and effective preparation of ultrafine CNFs （u-CNFs） with high surface area via electrospinning of two immiscible polymers [polyacrylonitrile （PAN） and poly（methyl methacry- late） （PMMA）] followed by calcination at high temperature in an inert atmosphere. Various electrospinning conditions were optimized in detail. Four different kinds of PAN/PMMA ratios （10/0, 7：3, 5：5 and 3：7） were chosen and found that the PAN/PMMA ratio of 3：7 （PAN/PMMA-3：7） is the optimum one. BET anal- ysis showed the specific surface area of the u-CNFs-3：7 was 46Z57 m2/g with an excellent pore volume （1.15 cms g-l） and an average pore size （9.48 nm）： it is about 25 times higher than the conventional CNFs （c-CNFs）. TEM and FE-SEM images confirmed the ultrafine structure of the CNFs with a thinner fiber di- ameter of-50 nm. The graphitic nature and atomic arrangement of the u-CNFs were investigated by Raman and XPS analyses. For the supercapacitor application, unlike the common electrode preparation methods, the u-CNFs-3：7 was used without any activation, chemical or mechanical modifications. The u-CNFs- 3：7 showed a better specific capacitance of 86 Fig in 1 mol/L 1-12S04 when compared to pure CNFs. The excellent physicochemical properties make the u-CNFs-3：7 an alternative choice to the existing CNFs for the supercapacitors.
文摘We report about current work which is aimed to improve the adhesion of melt processable elastomers onto relevant reinforcement materials by means of short wave UVC （ultraviolet C） light. Results of laboratory tests regarding UVC surface activation ofpolyamide fiber materials in air using low-pressure mercury lamps with 185 nm and 254 nm emissions are shown. The effect of irradiation on fiber strength was studied to find out suitable process parameters for providing the UVC treatment efficient but as gentle as possible to avoid negative effects on reinforcement properties. Application of a laboratory process for UVC pretreatment leads to significantly increased adhesion strength between the fibers and the melt processable elastomers on the base of TPA （polyamide） respectively TPU （polyurethane）.
基金supported by National Natural Science Foundation of China(Grant Nos.51377014,51407022 and 51677019)the National Key Research and Development program of China(2016YFC0207200)
文摘In this paper, a long line-shape dielectric barrier discharge excited by a nanosecond pulse and AC is generated in atmospheric air for the purpose of discussing the uniformity, stability and ability of aramid fiber treatment. The discharge images, waveforms of current and voltage,optical emission spectra, and gas temperatures of both discharges are compared. It is found that nanosecond pulsed discharge has a more uniform discharge morphology, higher energy efficiency and lower gas temperature, which indicates that nanosecond pulsed discharge is more suitable for surface modification. To reduce the water contact angle from 96° to about 60°, the energy cost is only about 1/7 compared with AC discharge. Scanning electron microscopy,Fourier transform infrared spectroscopy and x-ray photoelectron spectroscopy are employed to understand the mechanisms of hydrophilicity improvement.
基金Supported by the National Basic Research Program of China(2015CB655301)the Natural Science Foundation of Jiangsu Province(BK20150063)+1 种基金the Program of Excellent Innovation Teams of Jiangsu Higher Education Institutionsthe Project of Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘Porous polypropylene hollow fiber(PPHF) membranes are widely used in liquid purification. However, the hydrophobicity of polypropylene(PP) has limited its applications in water treatment. Herein, we demonstrate that, for the first time, atomic layer deposition(ALD) is an effective strategy to conveniently upgrade the filtration performances of PPHF membranes. The chemical and morphological changes of the deposited PPHF membranes are characterized by spectral, compositional, microscopic characterizations and protein adsorption measurements. Al_2O_3 is distributed along the cross section of the PP hollow fibers, with decreasing concentration from the outer surface to the inner surface. The pore size of the outer surface can be easily turned by altering the ALD cycles. Interestingly, the hollow fibers become much more ductile after deposition as their elongation at break is increased more than six times after deposition with 100 cycles. The deposited membranes show simultaneously enhanced water permeance and retention after deposition with moderate ALD cycle numbers.For instance, after 50 ALD cycles a 17% increase in water permeance and one-fold increase in BSA rejection are observed. Moreover, the PP membranes exhibit improved fouling-resistance after ALD deposition.
基金supported by the Natural Science Foundation of Xiamen, China (3502Z202373011)the Fundamental Research Funds for the Central Universities (20720220066, 20720230027)the National Key Project of China (2022-JCJQ-ZD-067-11)。
文摘Structure modulation at multiscale is crucialfor optimizing the electromagnetic wave absorption (EWA)properties of fiber-reinforced composites. Here we selectedtwo types of wave-absorbing SiC fibers as reinforcements. TheL-fiber had a relatively low resistivity of ~3 Ω·cm and the Hfiberhad a high resistivity of ~7×10^(5)Ω·cm. To adjust the impedance,BN single coating and SiO_(2)/BN dual-coating wereprepared respectively on the L-fibers. Unidirectional prepregswith different fibers were stacked in different rules to obtainthe final composites. It showed that both the fiber coatings andstacking structure significantly influence the EWA performanceof the composites. Guided by computational optimization,the stacked composites exhibited superior reflectionloss (RL) lower than −10 dB across the whole X(8.2–12.4 GHz) and Ku (12.4–18.0 GHz) bands. It is interestingto find that the introduction of the surface coatings on theL-fibers significantly widens the available thickness range ofthe stacked composite for possessing excellent performance. Inparticular, dual-coating perform better in terms of broadeningthe available thickness range of the stacked composites.
基金Natural Science Foundation of Shandong Province(ZR2022QF137)Double-Hundred Talent Plan of Shandong Province+3 种基金Special Construction Project Fund for Shandong Province Taishan Mountain ScholarsLiaocheng University(318052205,318052341)Science and Technology Support Plan for Youth Innovation of Colleges and Universities of Shandong Province of China(2022KJ107)Koneru Lakshmaiah Education Foundation。
文摘The ultralow limit of detection(LoD)and exceptional sensitivity of biosensors are a significant challenge currently faced in the field.To address this challenge,this work proposes a highly sensitive laser ring cavity biosensor capable of detecting low concentrations of des-γ-carboxy prothrombin(DCP).A tapered W-shaped fiber probe based on multi-mode fiber(MMF)-multi-core fiber(MCF)-MMF is developed to excite strong evanescent waves(EWs).By immobilizing gold nanorods(GNRs)on the fiber probe,localized surface plasmon resonance(LSPR)is generated at the near infrared wavelength to further enhance the sensitivity of the fiber probe.Moreover,an erbium-doped fiber(EDF)ring laser with a narrow full width at half maximum(FWHM)of 0.11 nm is employed as a light source.The spectrum with narrow FWHM has been demonstrated to obtain lower Lo D.Compared to the ASE light source,the Lo D of the laser ring cavity can be reduced by an order of magnitude.The developed biosensor is capable of detecting DCP within a concentration range of 0-1000 ng/mL,and the detection sensitivity of 0.265 nm/lg(ng/mL)and the Lo D of 367.6 pg/m L are obtained.In addition,the proposed laser ring cavity biosensor demonstrates good specificity,reproducibility,and repeatability by corresponding tests.The study results indicate that the proposed biosensor has potential in the detection of hepatocellular carcinoma markers.
基金National Natural Science Foundation of China(NSFC)(61525501)
文摘A high sensitivity D-shaped hole double-cladding fiber temperature sensor based on surface plasmon resonance(SPR)is designed and investigated by a full-vector finite element method.Within the D-shaped hole doublecladding fiber,the hollow D-section is coated with gold film and then injected in a high thermo-optic coefficient liquid to realize the high temperature sensitivity for the fiber SPR temperature sensor.The numerical simulation results show that the peaking loss of the D-shaped hole double-cladding fiber SPR is hugely influenced by the distance between the D-shaped hole and fiber core and by the thickness of the gold film,but the temperature sensitivity is almost insensitive to the above parameters.When the thermo-optic coefficient is -2.8×10^(-4)∕℃,the thickness of the gold film is 47 nm,and the distance between the D-shaped hole and fiber core is 5μm,the temperature sensitivity of the D-shaped hole fiber SPR sensor can reach to -3.635 nm∕℃.
文摘Reflective fiber optic sensors have advantages for surface roughness measurements of some special workpieces,but their measuring precision and efficiency need to be improved further. A least-squares support vector machine（LS-SVM）-based surface roughness prediction model is proposed to estimate the surface roughness, Ra, and the coupled simulated annealing（CSA） and standard simplex（SS） methods are combined for the parameter optimization of the mode. Experiments are conducted to test the performance of the proposed model, and the results show that the range of average relative errors is-4.232%–2.5709%. In comparison with the existing models, the LS-SVM-based model has the best performance in prediction precision, stability, and timesaving.
基金supported by the National"973"Programs of China(Nos.2013CBA01704,2010CB327405,and 2011CBA00608)the National Natural Science Foundation of China(Nos.61036011,61107050,and 61036010)
文摘An optical fiber sensor for ultrathin layer sensing based o51 short-range surface plasmon polariton （SRSPP） is proposed, and the sensing characteristics are theoretically analyzed. Simulation results indicate that even for a detecting layer much thinner than the vacuum wavelength, a resolution as high as 3.7×10-6 RIU can be obtained. Moreover, an average ttfickness-detection sensitivity of 6.2 dB/nm is obtained, which enables the sensor to detect the thickness variation of the ultrathin layer up to tens of nanometers. The sensitive region of thickness could be adjusted by tuning the structure parameters.
