Plant cell wall(CW)-like soft materials,referred to as artificial CWs,are composites of assembled polymers containing micro-/nanoparticles or fibers/fibrils that are designed to mimic the composition,structure,and mec...Plant cell wall(CW)-like soft materials,referred to as artificial CWs,are composites of assembled polymers containing micro-/nanoparticles or fibers/fibrils that are designed to mimic the composition,structure,and mechanics of plant CWs.CW-like materials have recently emerged to test hypotheses pertaining to the intricate structure–property relationships of native plant CWs or to fabricate functional materials.Here,research on plant CWs and CW-like materials is reviewed by distilling key studies on biomimetic composites primarily composed of plant polysaccharides,including cellulose,pectin,and hemicellulose,as well as organic polymers like lignin.Micro-and nanofabrication of plant CW-like composites,characterization techniques,and in silico studies are reviewed,with a brief overview of current and potential applications.Micro-/nanofabrication approaches include bacterial growth and impregnation,layer-by-layer assembly,film casting,3-dimensional templating microcapsules,and particle coating.Various characterization techniques are necessary for the comprehensive mechanical,chemical,morphological,and structural analyses of plant CWs and CW-like materials.CW-like materials demonstrate versatility in real-life applications,including biomass conversion,pulp and paper,food science,construction,catalysis,and reaction engineering.This review seeks to facilitate the rational design and thorough characterization of plant CW-mimetic materials,with the goal of advancing the development of innovative soft materials and elucidating the complex structure–property relationships inherent in native CWs.展开更多
The nutrient digestion,absorption and biological activity of bee pollen may be limited due to the complex pollen wall.Here,the effect of superfine grinding technology on the release of nutrients from bee pollen were i...The nutrient digestion,absorption and biological activity of bee pollen may be limited due to the complex pollen wall.Here,the effect of superfine grinding technology on the release of nutrients from bee pollen were investigated,and their antioxidant activities and in vitro digestion were explored in this study.Results showed that the content of nutrients in bee pollen increased after wall disruption.Among them,fat content increased by 22.55%-8.31%,protein content increased by 0.54%-4.91%,starch content increased by 36.31%-48.64%,soluble sugar content increased by 20.57%-29.67%,total phenolic acid content increased by 11.73%-86.98%and total flavonoids content increased by 14.29%-24.79%.At the same time,the antioxidant activity increased by 14.84%-46.00%.Furthermore,the active components such as phenolic compounds in the wall-disruption bee pollen were more readily to be released during the in vitro digestion,and easier to be absorbed because of their higher bioaccessibility.Antioxidant activities during in vitro digestion were also improved in walldisruption bee pollen.These findings provide evidence that bee pollen wall disruption was suggested,thus,it is more conducive to exerting the value of bee pollen in functional foods.展开更多
Prototype experiments were carried out on the explosion-proof performance of the RC blast wall.The mass of TNT detonated in the experiments is 5 kg and 20 kg respectively.The shock wave overpressure was tested in diff...Prototype experiments were carried out on the explosion-proof performance of the RC blast wall.The mass of TNT detonated in the experiments is 5 kg and 20 kg respectively.The shock wave overpressure was tested in different regions.The above experiments were numerically simulated,and the simulated shock wave overpressure waveforms were compared with that tested and given by CONWEP program.The results show that the numerically simulated waveform is slightly different from the test waveform,but similar to CONWEP waveform.Through dimensional analysis and numerical simulation under different working conditions,the equation for the attenuation rate of the diffraction overpressure behind the blast wall was obtained.According to the corresponding standards,the degree of casualties and the damage degree of the brick concrete building at a certain distance behind the wall can be determined when parameters are set.The above results can provide a reference for the design and construction of the reinforced concrete blast wall.展开更多
Investigations on domain wall(DW) and spin wave(SW) modes in a series of nanostrips with different widths and thicknesses have been carried out using micromagnetic simulation. The simulation results show that the freq...Investigations on domain wall(DW) and spin wave(SW) modes in a series of nanostrips with different widths and thicknesses have been carried out using micromagnetic simulation. The simulation results show that the frequencies of SW modes and the corresponding DW modes are consistent with each other if they have the same node number along the width direction. This consistency is more pronounced in wide and thin nanostrips, favoring the DW motion driven by SWs.Further analysis of the moving behavior of a DW driven by SWs is also carried out. The average DW speed can reach a larger value of ~ 140 m/s under two different SW sources. We argue that this study is very meaningful for the potential application of DW motion driven by SWs.展开更多
Effects of three-dimensional(3D)magnetic field perturbations due to feedback control of an unstable n=1(n is toroidal mode number)resistive wall mode(RWM)on the energetic particle(EP)losses are systematically investig...Effects of three-dimensional(3D)magnetic field perturbations due to feedback control of an unstable n=1(n is toroidal mode number)resistive wall mode(RWM)on the energetic particle(EP)losses are systematically investigated for the HL-3 tokamak.The MARS-F(Liu et al 2000 Phys.Plasmas 73681)code,facilitated by the test particle guiding center tracing module REORBIT,is utilized for the study.The RWM is found to generally produce no EP loss for cocurrent particles in HL-3.Assuming the same perturbation level at the sensor location for the close-loop system,feedback produces nearly the same loss of counter-current EPs compared to the open-loop case.Assuming however that the sensor signal is ten times smaller in the close-loop system than the open-loop counter part(reflecting the fact that the RWM is more stable with feedback),the counter-current EP loss is found significantly reduced in the former.Most of EP losses occur only for particles launched close to the plasma edge,while particles launched further away from the plasma boundary experience much less loss.The strike points of lost EPs on the HL-3 limiting surface become more scattered for particles launched closer to the plasma boundary.Taking into account the full gyro-orbit of particles while approaching the limiting surface,REORBIT finds slightly enhanced loss fraction.展开更多
The impact sensitivity assessment of spacecraft is to obtain the probability of spacecraft encountering the OD/M(orbital debris or meteoroid),which is a prerequisite for survivability assessment of on-orbit spacecraft...The impact sensitivity assessment of spacecraft is to obtain the probability of spacecraft encountering the OD/M(orbital debris or meteoroid),which is a prerequisite for survivability assessment of on-orbit spacecraft.An impact sensitivity assessment method of spacecraft based on virtual exterior wall was proposed to improve the computational efficiency.This method eliminates determination of the outermost surface elements of the spacecraft before generating the debris rays,which are assumed to originate from a non-concave virtual wall that completely wraps the spacecraft.The Dist Mesh method was adopted for the generating of the virtual wall to ensure its mesh quality.The influences of the sizes,mesh densities,shapes of the virtual wall on the efficiency and accuracy were considered to obtain the best combination of the size and mesh density of the wall and spacecraft.The results of this method were compared with those of S3DE(Survivability of Spacecraft in Space Debris Environment),BUMPER,MDPANTO,ESABASE2/Debris to verify the feasibility of the method.The PCHIP(Piecewise Cubic Hermite Interpolating Polynomial)was used to fit the size vs.flux relationship of the space debris to acquire the impact probability of OD/M with arbitrary size on the spacecraft.展开更多
The microbial induced calcium carbonate precipitation(MICP)technology provides a new approach to solve borehole destabilization in broken formations;however,the high-temperature and alkaline environments inhibit the g...The microbial induced calcium carbonate precipitation(MICP)technology provides a new approach to solve borehole destabilization in broken formations;however,the high-temperature and alkaline environments inhibit the growth of microorganisms,which in turn affects the performance of their wall enhancement performance.In this study,a pH and temperature-coupled induced domestication method was applied to Bacillus pasteurii,and its wall enhancement performance was evaluated.Post domestication,Bacillus pasteurii exhibited high growth activity at pH 10.3 and temperature 45℃.In a sodium carboxymethyl cellulose(CMC)drilling fluid environment,bacterial concentration reached 1.373 with urease activity at 1.98 after 24 h,and in a xanthan gum(XG)environment,the figures were 0.931 and 1.76,respectively—significantly higher than those before domestication.The Bacillus pasteurii-CMC system exhibited enhanced performance with the unconfined compressive strength of the specimen up to 1.232 MPa,permeability coefficient as low as 0.024,and calcium carbonate production up to 24.685 g.The crushed specimen portions remained lumpy with even calcium carbonate distribution.In contrast,the Bacillus pasteurii-XG system exhibited the highest unconfined compressive strength of 0.561 MPa,lowest permeability coefficient of 0.081,and the greatest calcium carbonate production of 16.03 g,with an externally cemented shell but internally loose structure and uneven calcium carbonate distribution,resulting in weaker mechanical properties.The Bacillus pasteurii induced predominantly vaterite calcium carbonate crystals in the CMC drilling fluid.In the XG drilling fluid,the crystals were mainly calcite.Both types effectively cemented the broken particles,improving formation strength and reducing permeability.However,under the same conditions,the Bacillus pasteurii-CMC system demonstrated a more pronounced enhancement effect.展开更多
In this paper,an induced current learning method(ICLM)for microwave through wall imaging(TWI),named as TWI-ICLM,is proposed.In the inversion of induced current,the unknown object along with the enclosed walls are trea...In this paper,an induced current learning method(ICLM)for microwave through wall imaging(TWI),named as TWI-ICLM,is proposed.In the inversion of induced current,the unknown object along with the enclosed walls are treated as a combination of scatterers.Firstly,a non-iterative method called distorted-Born backpropagation(DB-BP)is utilized to generate the initial result.In the training stage,several convolutional neural networks(CNNs)are cascaded to improve the estimated induced current.In addition,a hybrid loss function consisting of the induced current error and the permittivity error is used to optimize the network parameters.Finally,the relative permittivity images are conducted analytically using the predicted current based on ICLM.Both the numerical and experimental TWI tests prove that,the proposed method can achieve better imaging accuracy compared to traditional distorted-Born iterative method(DBIM).展开更多
The present article is devoted to nonlinear stochastic partial differential equations with double reflecting walls driven by possibly degenerate,multiplicative noise.We prove that the corresponding Markov semigroup po...The present article is devoted to nonlinear stochastic partial differential equations with double reflecting walls driven by possibly degenerate,multiplicative noise.We prove that the corresponding Markov semigroup possesses an exponentially attracting invariant measure through asymptotic coupling,in which Foias-Prodi estimation and the truncation technique are crucial for the realization of the Girsanov transform.展开更多
Due to the overlapping of echoes from the inner and outer walls of thin⁃walled tubes,thickness measurement based on ultrasonic time⁃of⁃flight method is difficult to apply.Therefore,the ultrasonic resonance method has ...Due to the overlapping of echoes from the inner and outer walls of thin⁃walled tubes,thickness measurement based on ultrasonic time⁃of⁃flight method is difficult to apply.Therefore,the ultrasonic resonance method has become an effective mean of measuring thin⁃walled tube thickness.The resonance method often demands a perpendicular incidence of ultrasound,but having the ultrasonic probe strictly perpendicular to the measured surface is challenging for installation reasons.The ultrasonic resonance model by considering ultrasonic inclination angles is derived.The model explains that an inclination angle theoretically does not affect the calculation results of measuring thin thickness.However,increasing the inclination angle reduces the reflection coefficient,resulting in a shorter length of the effective reflected wave,thus reducing the calculation accuracy.Additionally,the research evaluated the ultrasonic echo from the tubes of different diameters and found that if ultrasound transmits with an inclined incidence,smaller diameter tubes result in lower normal reflection coefficients,leading to poorer measurement accuracy.The research simulated and tested the tilted⁃incidence resonant method based on the subject of water⁃steel⁃air,and the results prove the correctness of the model.展开更多
基金supported as part of The Center for LignoCellulose Structure and Formation,an Energy Frontier Research Center funded by the U.S.Department of Energy,Office of Science,Basic Energy Sciences under Award#DE-SC0001090support from the Huck Institutes of the Life Sciences at Penn State University through the Patricia and Stephen Benkovic Research Initiativesupported by the Center for Engineering Mechano Biology(CEMB),an NSF Science and Technology Center,under grant agreement CMMI:15-48571。
文摘Plant cell wall(CW)-like soft materials,referred to as artificial CWs,are composites of assembled polymers containing micro-/nanoparticles or fibers/fibrils that are designed to mimic the composition,structure,and mechanics of plant CWs.CW-like materials have recently emerged to test hypotheses pertaining to the intricate structure–property relationships of native plant CWs or to fabricate functional materials.Here,research on plant CWs and CW-like materials is reviewed by distilling key studies on biomimetic composites primarily composed of plant polysaccharides,including cellulose,pectin,and hemicellulose,as well as organic polymers like lignin.Micro-and nanofabrication of plant CW-like composites,characterization techniques,and in silico studies are reviewed,with a brief overview of current and potential applications.Micro-/nanofabrication approaches include bacterial growth and impregnation,layer-by-layer assembly,film casting,3-dimensional templating microcapsules,and particle coating.Various characterization techniques are necessary for the comprehensive mechanical,chemical,morphological,and structural analyses of plant CWs and CW-like materials.CW-like materials demonstrate versatility in real-life applications,including biomass conversion,pulp and paper,food science,construction,catalysis,and reaction engineering.This review seeks to facilitate the rational design and thorough characterization of plant CW-mimetic materials,with the goal of advancing the development of innovative soft materials and elucidating the complex structure–property relationships inherent in native CWs.
基金the Program of State Key Laboratory of Food Science and Technology,Nanchang University (SKLF-ZZB-202119)。
文摘The nutrient digestion,absorption and biological activity of bee pollen may be limited due to the complex pollen wall.Here,the effect of superfine grinding technology on the release of nutrients from bee pollen were investigated,and their antioxidant activities and in vitro digestion were explored in this study.Results showed that the content of nutrients in bee pollen increased after wall disruption.Among them,fat content increased by 22.55%-8.31%,protein content increased by 0.54%-4.91%,starch content increased by 36.31%-48.64%,soluble sugar content increased by 20.57%-29.67%,total phenolic acid content increased by 11.73%-86.98%and total flavonoids content increased by 14.29%-24.79%.At the same time,the antioxidant activity increased by 14.84%-46.00%.Furthermore,the active components such as phenolic compounds in the wall-disruption bee pollen were more readily to be released during the in vitro digestion,and easier to be absorbed because of their higher bioaccessibility.Antioxidant activities during in vitro digestion were also improved in walldisruption bee pollen.These findings provide evidence that bee pollen wall disruption was suggested,thus,it is more conducive to exerting the value of bee pollen in functional foods.
基金funded by Key R&D Projects in Hubei Province (Grant No.2020BCA084)Innovative Group Project of Hubei Natural Science Foundation (Grant No.2020CFA043)。
文摘Prototype experiments were carried out on the explosion-proof performance of the RC blast wall.The mass of TNT detonated in the experiments is 5 kg and 20 kg respectively.The shock wave overpressure was tested in different regions.The above experiments were numerically simulated,and the simulated shock wave overpressure waveforms were compared with that tested and given by CONWEP program.The results show that the numerically simulated waveform is slightly different from the test waveform,but similar to CONWEP waveform.Through dimensional analysis and numerical simulation under different working conditions,the equation for the attenuation rate of the diffraction overpressure behind the blast wall was obtained.According to the corresponding standards,the degree of casualties and the damage degree of the brick concrete building at a certain distance behind the wall can be determined when parameters are set.The above results can provide a reference for the design and construction of the reinforced concrete blast wall.
基金Project supported by the Fundamental Research Funds for the Central Universities (Grant No. 20720210030)the National Natural Science Foundation of China (Grant No. 11204255)。
文摘Investigations on domain wall(DW) and spin wave(SW) modes in a series of nanostrips with different widths and thicknesses have been carried out using micromagnetic simulation. The simulation results show that the frequencies of SW modes and the corresponding DW modes are consistent with each other if they have the same node number along the width direction. This consistency is more pronounced in wide and thin nanostrips, favoring the DW motion driven by SWs.Further analysis of the moving behavior of a DW driven by SWs is also carried out. The average DW speed can reach a larger value of ~ 140 m/s under two different SW sources. We argue that this study is very meaningful for the potential application of DW motion driven by SWs.
基金supported by the National Magnetic Confinement Fusion Science Program of China(Nos.2022YFE03090000 and 2022YFE03060002)National Natural Science Foundation of China(No.12375214)+3 种基金China National Nuclear Corporation Fundamental Research Program(No.CNNC-JCYJ-202236)Innovation Program of Southwestern Institute of Physics(No.202301XWCX006-04)supported by Youth Science and Technology Innovation Team of Sichuan Province(No.2022JDTD0003)US DoE Office of Science(Nos.DE-FG02-95ER54309 and DE-FC02-04ER54698)。
文摘Effects of three-dimensional(3D)magnetic field perturbations due to feedback control of an unstable n=1(n is toroidal mode number)resistive wall mode(RWM)on the energetic particle(EP)losses are systematically investigated for the HL-3 tokamak.The MARS-F(Liu et al 2000 Phys.Plasmas 73681)code,facilitated by the test particle guiding center tracing module REORBIT,is utilized for the study.The RWM is found to generally produce no EP loss for cocurrent particles in HL-3.Assuming the same perturbation level at the sensor location for the close-loop system,feedback produces nearly the same loss of counter-current EPs compared to the open-loop case.Assuming however that the sensor signal is ten times smaller in the close-loop system than the open-loop counter part(reflecting the fact that the RWM is more stable with feedback),the counter-current EP loss is found significantly reduced in the former.Most of EP losses occur only for particles launched close to the plasma edge,while particles launched further away from the plasma boundary experience much less loss.The strike points of lost EPs on the HL-3 limiting surface become more scattered for particles launched closer to the plasma boundary.Taking into account the full gyro-orbit of particles while approaching the limiting surface,REORBIT finds slightly enhanced loss fraction.
文摘The impact sensitivity assessment of spacecraft is to obtain the probability of spacecraft encountering the OD/M(orbital debris or meteoroid),which is a prerequisite for survivability assessment of on-orbit spacecraft.An impact sensitivity assessment method of spacecraft based on virtual exterior wall was proposed to improve the computational efficiency.This method eliminates determination of the outermost surface elements of the spacecraft before generating the debris rays,which are assumed to originate from a non-concave virtual wall that completely wraps the spacecraft.The Dist Mesh method was adopted for the generating of the virtual wall to ensure its mesh quality.The influences of the sizes,mesh densities,shapes of the virtual wall on the efficiency and accuracy were considered to obtain the best combination of the size and mesh density of the wall and spacecraft.The results of this method were compared with those of S3DE(Survivability of Spacecraft in Space Debris Environment),BUMPER,MDPANTO,ESABASE2/Debris to verify the feasibility of the method.The PCHIP(Piecewise Cubic Hermite Interpolating Polynomial)was used to fit the size vs.flux relationship of the space debris to acquire the impact probability of OD/M with arbitrary size on the spacecraft.
基金supported by the State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Independent Research Project(SKLGP2023Z012)the National Natural Science Foundation of China(Grant No.41702388)the Everest Technology Research Proposal of Chengdu University of Technology(Grant No.80000-2023ZF11411)。
文摘The microbial induced calcium carbonate precipitation(MICP)technology provides a new approach to solve borehole destabilization in broken formations;however,the high-temperature and alkaline environments inhibit the growth of microorganisms,which in turn affects the performance of their wall enhancement performance.In this study,a pH and temperature-coupled induced domestication method was applied to Bacillus pasteurii,and its wall enhancement performance was evaluated.Post domestication,Bacillus pasteurii exhibited high growth activity at pH 10.3 and temperature 45℃.In a sodium carboxymethyl cellulose(CMC)drilling fluid environment,bacterial concentration reached 1.373 with urease activity at 1.98 after 24 h,and in a xanthan gum(XG)environment,the figures were 0.931 and 1.76,respectively—significantly higher than those before domestication.The Bacillus pasteurii-CMC system exhibited enhanced performance with the unconfined compressive strength of the specimen up to 1.232 MPa,permeability coefficient as low as 0.024,and calcium carbonate production up to 24.685 g.The crushed specimen portions remained lumpy with even calcium carbonate distribution.In contrast,the Bacillus pasteurii-XG system exhibited the highest unconfined compressive strength of 0.561 MPa,lowest permeability coefficient of 0.081,and the greatest calcium carbonate production of 16.03 g,with an externally cemented shell but internally loose structure and uneven calcium carbonate distribution,resulting in weaker mechanical properties.The Bacillus pasteurii induced predominantly vaterite calcium carbonate crystals in the CMC drilling fluid.In the XG drilling fluid,the crystals were mainly calcite.Both types effectively cemented the broken particles,improving formation strength and reducing permeability.However,under the same conditions,the Bacillus pasteurii-CMC system demonstrated a more pronounced enhancement effect.
基金National Natural Science Foundation of China(No.62101288)。
文摘In this paper,an induced current learning method(ICLM)for microwave through wall imaging(TWI),named as TWI-ICLM,is proposed.In the inversion of induced current,the unknown object along with the enclosed walls are treated as a combination of scatterers.Firstly,a non-iterative method called distorted-Born backpropagation(DB-BP)is utilized to generate the initial result.In the training stage,several convolutional neural networks(CNNs)are cascaded to improve the estimated induced current.In addition,a hybrid loss function consisting of the induced current error and the permittivity error is used to optimize the network parameters.Finally,the relative permittivity images are conducted analytically using the predicted current based on ICLM.Both the numerical and experimental TWI tests prove that,the proposed method can achieve better imaging accuracy compared to traditional distorted-Born iterative method(DBIM).
基金supported by the National Natural Science Foundation of China(12071480)the Scientific Research Program Funds of NUDT(22-ZZCX-016)the Hunan Provincial Innovation Foundation for Postgraduate(CX20230003)。
文摘The present article is devoted to nonlinear stochastic partial differential equations with double reflecting walls driven by possibly degenerate,multiplicative noise.We prove that the corresponding Markov semigroup possesses an exponentially attracting invariant measure through asymptotic coupling,in which Foias-Prodi estimation and the truncation technique are crucial for the realization of the Girsanov transform.
文摘Due to the overlapping of echoes from the inner and outer walls of thin⁃walled tubes,thickness measurement based on ultrasonic time⁃of⁃flight method is difficult to apply.Therefore,the ultrasonic resonance method has become an effective mean of measuring thin⁃walled tube thickness.The resonance method often demands a perpendicular incidence of ultrasound,but having the ultrasonic probe strictly perpendicular to the measured surface is challenging for installation reasons.The ultrasonic resonance model by considering ultrasonic inclination angles is derived.The model explains that an inclination angle theoretically does not affect the calculation results of measuring thin thickness.However,increasing the inclination angle reduces the reflection coefficient,resulting in a shorter length of the effective reflected wave,thus reducing the calculation accuracy.Additionally,the research evaluated the ultrasonic echo from the tubes of different diameters and found that if ultrasound transmits with an inclined incidence,smaller diameter tubes result in lower normal reflection coefficients,leading to poorer measurement accuracy.The research simulated and tested the tilted⁃incidence resonant method based on the subject of water⁃steel⁃air,and the results prove the correctness of the model.
