Research in the nanofibers field is attracting an ever-increasing attention from the industrial and academic sector. This attention is justified by the high specific surface area and high porosity, diversity of physic...Research in the nanofibers field is attracting an ever-increasing attention from the industrial and academic sector. This attention is justified by the high specific surface area and high porosity, diversity of physical/chemical modification, and simplicity of hybridization. This review summarizes the state-of-the-art progress on the fabrication of polymeric nanofibers(PNFs) with particular emphasis on their scalable productions for emerging applications. First, the engineering processes and equipment for PNFs production are briefly introduced, and the effects of the polymer precursors, operational parameters, and environmental conditions on the nanofiber’s formation are illustrated. The past achievements and current challenges of PNF preparation in industrial production are also discussed. Hybridization methods to prepare multifunctional composite nanofibers are also reviewed, including organic incorporation modification, loading functional inorganic nanomaterials, and biological active components on/into nanofibers. Given these hybridizations and functions, a variety of applications are then discussed, focusing mainly on environmental and biomedical applications. Finally, conclusions are drawn and prospects are given according to the reviewed research.展开更多
With performance improvements,organic photovoltaics(OPVs)are an increasingly competitive technology for renewable energy.However,most high-performance OPVs are small-area devices processed from toxic halogenated solve...With performance improvements,organic photovoltaics(OPVs)are an increasingly competitive technology for renewable energy.However,most high-performance OPVs are small-area devices processed from toxic halogenated solvents via spin-coating,posing a challenge for mass production.We study a low-cost polymer donor(PTQ10)and a nonfullerene acceptor(DTY6)in a halogen-free solvent using industrially relevant blade coating.The non-inverted architecture performed best,achieving 12%efficiency,with the blade-coating deposition surpassing spin-coating.Active layers processed from the two coating techniques exhibited similar exciton quenching,likely due to the same measured nanodomain size and purity.However,blade-coated devices exhibited a higher charge carrier lifetime correlated with increased acceptor pi-stacking despite decreased donor pi-stacking.This suggests that optimizing crystallinity in bladecoated devices could result in even higher performance.Additionally,high performance in upscaled blade-coated devices(1 cm2)processed in air with a green solvent demonstrated the industrial potential of this system.展开更多
By nature, pineapple fiber (PALF) obtained from pineapple leaf is a smooth, shiny and white natural cellulosic fiber. In current investigation of spinning technique for pineapple leaf fiber based on cotton spinning me...By nature, pineapple fiber (PALF) obtained from pineapple leaf is a smooth, shiny and white natural cellulosic fiber. In current investigation of spinning technique for pineapple leaf fiber based on cotton spinning method comparison of produced yarn properties has been reported. For one of the investigations of this study, the fibers were cut into staple length and various properties of fibers were analyzed. Data and results acquired from this illustrated that there is excellent spinnability on the fiber. Two separate researches were conducted with consideration to produce resultant yarn by spinning of PALF. Yarn derived by solo spinning technique of 100% PALF and PALF blending with polyester and cotton fibers through binary blending technique in equal proportion has been spun, then yarn count, tensile properties, yarn evenness, hairiness have been evaluated and analyzed. The results from numerical simulations analysis indicated that yarn obtained from the Pineapple leaf fiber (PALF) had great potential to be used in apparels.展开更多
Cerebral blood flow is strongly associated with brain function, and is the main symptom and diagnostic basis for a variety of encephalopathies. However, changes in cerebral blood flow after mild traumatic brain injury...Cerebral blood flow is strongly associated with brain function, and is the main symptom and diagnostic basis for a variety of encephalopathies. However, changes in cerebral blood flow after mild traumatic brain injury remain poorly understood. This study sought to observe changes in cerebral blood flow in different regions after mild traumatic brain injury using pulsed arterial spin labeling. Our results demonstrate maximal cerebral blood flow in gray matter and minimal in the white matter of patients with mild traumatic brain injury. At the acute and subacute stages, cerebral blood flow was reduced in the occipital lobe, parietal lobe, central region, subcutaneous region, and frontal lobe. Cerebral blood flow was restored at the chronic stage. At the acute, subacute, and chronic stages, changes in cerebral blood flow were not apparent in the insula. Cerebral blood flow in the temporal lobe and limbic lobe diminished at the acute and subacute stages, but was restored at the chronic stage. These findings suggest that pulsed arterial spin labeling can precisely measure cerebral blood flow in various brain regions, and may play a reference role in evaluating a patient＇s condition and judging prognosis after traumatic brain injury.展开更多
Three thicknesses of TiO2 films, 174, 195, and 229 nm, were deposited onto quartz substrates by sol–gel spin coating method. The as-deposited thin films were characterized by nano-crystallite with different sizes (19...Three thicknesses of TiO2 films, 174, 195, and 229 nm, were deposited onto quartz substrates by sol–gel spin coating method. The as-deposited thin films were characterized by nano-crystallite with different sizes (19–46 nm) and relatively high porous structure. Optical constants were determined and showed the lowest refractive index of 1.66 for the as-prepared films that ever reported till now. Obtained results were discussed through current theoretical ideas.展开更多
This article presents a complete nonlinear controller design for a class of spin-stabilized canard-controlled projectiles.Uniformly ultimate boundedness and tracking are achieved,exploiting a heavily coupled,bounded u...This article presents a complete nonlinear controller design for a class of spin-stabilized canard-controlled projectiles.Uniformly ultimate boundedness and tracking are achieved,exploiting a heavily coupled,bounded uncertain and highly nonlinear model of longitudinal and lateral dynamics.In order to estimate unmeasurable states,an observer is proposed for an augmented multiple-input-multiple-output（MIMO） nonlinear system with an adaptive sliding mode term against the disturbances.Under the frame of a backstepping design,an adaptive sliding mode output-feedback dynamic surface control（DSC） approach is derived recursively by virtue of the estimated states.The DSC technique is adopted to overcome the problem of ‘‘explosion of complexity＂ and relieve the stress of the guidance loop.It is proven that all signals of the MIMO closed-loop system,including the observer and controller,are uniformly ultimately bounded,and the tracking errors converge to an arbitrarily small neighborhood of the origin.Simulation results for the observer and controller are provided to illustrate the feasibility and effectiveness of the proposed approach.展开更多
This paper reports the synthesis and characterization of ZnO thin films prepared by sol-gel spin coating technique. The sol-gel was prepared from zinc acetate dehydrate as a precursor, 2-me- thoxyethanol as a solvent ...This paper reports the synthesis and characterization of ZnO thin films prepared by sol-gel spin coating technique. The sol-gel was prepared from zinc acetate dehydrate as a precursor, 2-me- thoxyethanol as a solvent and di-ethanolamine as a stabilizer, and then deposited on glass substrate using spin coater at the coating speed of 1000 rpm, 2000 rpm, 3000 rpm, 4000 rpm, 5000 rpm and 6000 rpm. After pre-heated at 150℃, the samples were post-heated at 250oC and also annealed at 400℃. X-ray diffraction (XRD) of the films showed polycrystalline hexagonal structure, with (002) orientation as most intense peak having a grain size of 28.1 nm. The absorbance of the film decreases with increasing wavelength and the transmittance was generally high between visible regions from 280 nm - 1200 nm. The ZnO films deposited at a spinning speed of 2000 rpm had highest transmittance of 88% in the visible region from 280 nm - 1200 nm. The energy band gap was found to be in the range of 3.23 - 3.40 eV. The thicknesses of the films decreased with increase in coating speed. Based on these results, ZnO thin films obtained could have useful application in transparent conducting oxide electrode in solar cells.展开更多
Cerebrovascular disease is a disease with high morbidity,disability and mortality rates,which seri-ously affects the daily life of patients and is a heavy burden on families and society.Arterial spin labeling(ASL)is a...Cerebrovascular disease is a disease with high morbidity,disability and mortality rates,which seri-ously affects the daily life of patients and is a heavy burden on families and society.Arterial spin labeling(ASL)is a magnetic resonance imaging(MRI)technology that uses the magnetic labeling of hydrogen atoms in arterial blood as tracers to noninvasively evaluate brain blood flow.ASL does not require injection of an exogenous contrast agent,and has the advantages of no radiation,simplicity and low cost.In cerebrovascular diseases,ASL can evaluate the collateral cerebrovascular circulation and abnormal perfusion of brain tissue,which can provide a reliable basis for early diagnosis and clinical decision-making.This study reviewed ASL and its application in the diagnosis,treatment and prognosis of cerebrovascular diseases.展开更多
Ⅰ. INTRODUCTIONIn our previous studies the cleavage reaction of Co—C bond of RCo（Salen） L [Salen=bis （salicyladehyde）ethylenediamine, L= H<sub>2</sub>O or without H<sub>2</sub>O, R= CH<...Ⅰ. INTRODUCTIONIn our previous studies the cleavage reaction of Co—C bond of RCo（Salen） L [Salen=bis （salicyladehyde）ethylenediamine, L= H<sub>2</sub>O or without H<sub>2</sub>O, R= CH<sub>3</sub>·, C<sub>2</sub>H<sub>5</sub>·, n-and i-C<sub>3</sub>H<sub>7</sub>·, n-, i- and t-C<sub>4</sub>H<sub>9</sub>·] in methanol on photolysis or thermolysis was obtained:展开更多
A novel two-step method is employed, for the first time, to fabricatc nonvolatile memory devices that have metal nanoerystals. First, size-averaged Au nanocrystals are synthesized chemically; second, they are assemble...A novel two-step method is employed, for the first time, to fabricatc nonvolatile memory devices that have metal nanoerystals. First, size-averaged Au nanocrystals are synthesized chemically; second, they are assembled into memory devices by a spin-coating technique at room temperature. This attractive approach makes it possible to tailor the diameter and control the density of nanocrystals individually. In addition, processes at room temperature prevent Au diffusion, which is a main concem for the application of metal nanocrystal-based memory. The experimental results, both the morphology characterization and the electrical measurements, reveal that there is an optimum density of nanocrystal monolayer to balance between long data retention and a large hysteresis memory window. At the same time, density-controllable devices could also feed the preferential emphasis on either memory window or retention time. All these facts confirm the advantages and novelty of our two-step method.展开更多
基金Fundamental Research Funds for the Central Universities(Grant No.19D110618)the Initial Research Funds for Young Teachers of Donghua University(Grant No.106-07-0053029)+2 种基金the Program for National Key Research and Development Program of China(Grant Nos.2016YFA0201702 and 2016YFA0201700)the Fundamental Research Funds for the Central Universities(Grant Nos.2232018A3-01 and 2232018D3-03)the National Natural Science Foundation of China(Grant No.51733002).
文摘Research in the nanofibers field is attracting an ever-increasing attention from the industrial and academic sector. This attention is justified by the high specific surface area and high porosity, diversity of physical/chemical modification, and simplicity of hybridization. This review summarizes the state-of-the-art progress on the fabrication of polymeric nanofibers(PNFs) with particular emphasis on their scalable productions for emerging applications. First, the engineering processes and equipment for PNFs production are briefly introduced, and the effects of the polymer precursors, operational parameters, and environmental conditions on the nanofiber’s formation are illustrated. The past achievements and current challenges of PNF preparation in industrial production are also discussed. Hybridization methods to prepare multifunctional composite nanofibers are also reviewed, including organic incorporation modification, loading functional inorganic nanomaterials, and biological active components on/into nanofibers. Given these hybridizations and functions, a variety of applications are then discussed, focusing mainly on environmental and biomedical applications. Finally, conclusions are drawn and prospects are given according to the reviewed research.
基金the US National Science Foundation(NSF),Division of Materials Research,Electronic and Photonic Materials Program under grant#2247711support from the Bio Voltaico project n.A0613-2023-078175 of the POR FESR 2021/2027 Riposizionamento Competitivo RSI-Economia del Mare,Green Economy e Agrifood initiative,and Integrated Terrestrial And Non-Terrestrial Networks(ITANTN)project under the Research and innovation on future Telecommunications systems and networks,to make Italy more smart(RESTART)initiative of the PNRRsupported by the NSF Division of Physics Research Experience for Undergraduates under grant#2349426。
文摘With performance improvements,organic photovoltaics(OPVs)are an increasingly competitive technology for renewable energy.However,most high-performance OPVs are small-area devices processed from toxic halogenated solvents via spin-coating,posing a challenge for mass production.We study a low-cost polymer donor(PTQ10)and a nonfullerene acceptor(DTY6)in a halogen-free solvent using industrially relevant blade coating.The non-inverted architecture performed best,achieving 12%efficiency,with the blade-coating deposition surpassing spin-coating.Active layers processed from the two coating techniques exhibited similar exciton quenching,likely due to the same measured nanodomain size and purity.However,blade-coated devices exhibited a higher charge carrier lifetime correlated with increased acceptor pi-stacking despite decreased donor pi-stacking.This suggests that optimizing crystallinity in bladecoated devices could result in even higher performance.Additionally,high performance in upscaled blade-coated devices(1 cm2)processed in air with a green solvent demonstrated the industrial potential of this system.
文摘By nature, pineapple fiber (PALF) obtained from pineapple leaf is a smooth, shiny and white natural cellulosic fiber. In current investigation of spinning technique for pineapple leaf fiber based on cotton spinning method comparison of produced yarn properties has been reported. For one of the investigations of this study, the fibers were cut into staple length and various properties of fibers were analyzed. Data and results acquired from this illustrated that there is excellent spinnability on the fiber. Two separate researches were conducted with consideration to produce resultant yarn by spinning of PALF. Yarn derived by solo spinning technique of 100% PALF and PALF blending with polyester and cotton fibers through binary blending technique in equal proportion has been spun, then yarn count, tensile properties, yarn evenness, hairiness have been evaluated and analyzed. The results from numerical simulations analysis indicated that yarn obtained from the Pineapple leaf fiber (PALF) had great potential to be used in apparels.
文摘Cerebral blood flow is strongly associated with brain function, and is the main symptom and diagnostic basis for a variety of encephalopathies. However, changes in cerebral blood flow after mild traumatic brain injury remain poorly understood. This study sought to observe changes in cerebral blood flow in different regions after mild traumatic brain injury using pulsed arterial spin labeling. Our results demonstrate maximal cerebral blood flow in gray matter and minimal in the white matter of patients with mild traumatic brain injury. At the acute and subacute stages, cerebral blood flow was reduced in the occipital lobe, parietal lobe, central region, subcutaneous region, and frontal lobe. Cerebral blood flow was restored at the chronic stage. At the acute, subacute, and chronic stages, changes in cerebral blood flow were not apparent in the insula. Cerebral blood flow in the temporal lobe and limbic lobe diminished at the acute and subacute stages, but was restored at the chronic stage. These findings suggest that pulsed arterial spin labeling can precisely measure cerebral blood flow in various brain regions, and may play a reference role in evaluating a patient＇s condition and judging prognosis after traumatic brain injury.
文摘Three thicknesses of TiO2 films, 174, 195, and 229 nm, were deposited onto quartz substrates by sol–gel spin coating method. The as-deposited thin films were characterized by nano-crystallite with different sizes (19–46 nm) and relatively high porous structure. Optical constants were determined and showed the lowest refractive index of 1.66 for the as-prepared films that ever reported till now. Obtained results were discussed through current theoretical ideas.
基金supported by the National Natural Science Foundation of China(No.11532002)
文摘This article presents a complete nonlinear controller design for a class of spin-stabilized canard-controlled projectiles.Uniformly ultimate boundedness and tracking are achieved,exploiting a heavily coupled,bounded uncertain and highly nonlinear model of longitudinal and lateral dynamics.In order to estimate unmeasurable states,an observer is proposed for an augmented multiple-input-multiple-output（MIMO） nonlinear system with an adaptive sliding mode term against the disturbances.Under the frame of a backstepping design,an adaptive sliding mode output-feedback dynamic surface control（DSC） approach is derived recursively by virtue of the estimated states.The DSC technique is adopted to overcome the problem of ‘‘explosion of complexity＂ and relieve the stress of the guidance loop.It is proven that all signals of the MIMO closed-loop system,including the observer and controller,are uniformly ultimately bounded,and the tracking errors converge to an arbitrarily small neighborhood of the origin.Simulation results for the observer and controller are provided to illustrate the feasibility and effectiveness of the proposed approach.
文摘This paper reports the synthesis and characterization of ZnO thin films prepared by sol-gel spin coating technique. The sol-gel was prepared from zinc acetate dehydrate as a precursor, 2-me- thoxyethanol as a solvent and di-ethanolamine as a stabilizer, and then deposited on glass substrate using spin coater at the coating speed of 1000 rpm, 2000 rpm, 3000 rpm, 4000 rpm, 5000 rpm and 6000 rpm. After pre-heated at 150℃, the samples were post-heated at 250oC and also annealed at 400℃. X-ray diffraction (XRD) of the films showed polycrystalline hexagonal structure, with (002) orientation as most intense peak having a grain size of 28.1 nm. The absorbance of the film decreases with increasing wavelength and the transmittance was generally high between visible regions from 280 nm - 1200 nm. The ZnO films deposited at a spinning speed of 2000 rpm had highest transmittance of 88% in the visible region from 280 nm - 1200 nm. The energy band gap was found to be in the range of 3.23 - 3.40 eV. The thicknesses of the films decreased with increase in coating speed. Based on these results, ZnO thin films obtained could have useful application in transparent conducting oxide electrode in solar cells.
文摘Cerebrovascular disease is a disease with high morbidity,disability and mortality rates,which seri-ously affects the daily life of patients and is a heavy burden on families and society.Arterial spin labeling(ASL)is a magnetic resonance imaging(MRI)technology that uses the magnetic labeling of hydrogen atoms in arterial blood as tracers to noninvasively evaluate brain blood flow.ASL does not require injection of an exogenous contrast agent,and has the advantages of no radiation,simplicity and low cost.In cerebrovascular diseases,ASL can evaluate the collateral cerebrovascular circulation and abnormal perfusion of brain tissue,which can provide a reliable basis for early diagnosis and clinical decision-making.This study reviewed ASL and its application in the diagnosis,treatment and prognosis of cerebrovascular diseases.
基金Project supported by the National Natural Science Foundation of China.
文摘Ⅰ. INTRODUCTIONIn our previous studies the cleavage reaction of Co—C bond of RCo（Salen） L [Salen=bis （salicyladehyde）ethylenediamine, L= H<sub>2</sub>O or without H<sub>2</sub>O, R= CH<sub>3</sub>·, C<sub>2</sub>H<sub>5</sub>·, n-and i-C<sub>3</sub>H<sub>7</sub>·, n-, i- and t-C<sub>4</sub>H<sub>9</sub>·] in methanol on photolysis or thermolysis was obtained:
文摘A novel two-step method is employed, for the first time, to fabricatc nonvolatile memory devices that have metal nanoerystals. First, size-averaged Au nanocrystals are synthesized chemically; second, they are assembled into memory devices by a spin-coating technique at room temperature. This attractive approach makes it possible to tailor the diameter and control the density of nanocrystals individually. In addition, processes at room temperature prevent Au diffusion, which is a main concem for the application of metal nanocrystal-based memory. The experimental results, both the morphology characterization and the electrical measurements, reveal that there is an optimum density of nanocrystal monolayer to balance between long data retention and a large hysteresis memory window. At the same time, density-controllable devices could also feed the preferential emphasis on either memory window or retention time. All these facts confirm the advantages and novelty of our two-step method.
