The construction of complex superlattices using homogenous soft matter has great potential for the bottom-up fabrication of complex,nanoscale structures.This topic is not only interested in scientific exploring for ne...The construction of complex superlattices using homogenous soft matter has great potential for the bottom-up fabrication of complex,nanoscale structures.This topic is not only interested in scientific exploring for new concepts of supramolecular crystals with nanometer in sizes,which is about thousand times larger in volumes than those of normal crystals,but also practically important to provide construction principles of metamaterials which are artificially structured materials for controlling and manipulating light,sound,and other physical behaviors.These systems have fast assembly kinetics and convenient processing procedures,making them ideal for large-scale superlattice production.In this perspective,we focus on recent developments in the construction of complex spherical packing superlattices using homogenous soft self-assemblies.We discuss the general mechanism of those formations of supramolecular motifs and provide an overview of the spherical packing superlattices self-assembled by homogenous soft matters based on different volume asymmetry.Additionally,we outline the potentials of utilizing this approach in constructing novel superlattices as well as its future challenges.展开更多
Ray tracing Particle Image Velocimetry(RT-PIV)is an optical technique for high resolution velocity measurements in challenging optical systems,such as transparent packed beds,that uses ray tracing to correct for disto...Ray tracing Particle Image Velocimetry(RT-PIV)is an optical technique for high resolution velocity measurements in challenging optical systems,such as transparent packed beds,that uses ray tracing to correct for distortions introduced by transparent geometries in the light paths.The ray tracing based correction is a post processing step applied to the raw PIV particle images before classical PIV evaluation.In this study,RT-PIV is performed in the top layer of a body centred cubic(bcc)sphere packing with gaseous flow,where optical access is obtained by the use of transparent N-BK7 glass balls with a diameter of d=40 mm.RT-PIV introduces new experimental and numerical challenges,for example a limited field of view,illumination difficulties,a very large required depth of field and high sensitivity to geometric parameters used in the ray tracing correction.These challenges and their implications are the main scope and discussed in the present work.Further,the validation of the ray tracing reconstruction step is presented and examples for the obtained corrected vector fields in a packed bed are given.The results show the strength of the method in reconstructing velocity fields behind transparent spheres that would not have been accessible by optical measurement techniques without the ray tracing correction.展开更多
The application of iron–carbon(Fe–C)micro-electrolysis to wastewater treatment is limited by the passivation potential of the Fe–C packing.In order to address this problem,high-gravity intensified Fe–C micro-elect...The application of iron–carbon(Fe–C)micro-electrolysis to wastewater treatment is limited by the passivation potential of the Fe–C packing.In order to address this problem,high-gravity intensified Fe–C micro-electrolysis was proposed in this study for degradation of dinitrotoluene wastewater in a rotating packed bed(RPB)using commercial Fe–C particles as the packing.The effects of reaction time,high-gravity factor,liquid flow rate and initial solution pH were investigated.The degradation intermediates were determined by gas chromatography-mass spectrometry,and the possible degradation pathways of nitro compounds by Fe–C micro-electrolysis in RPB were also proposed.It is found that under optimal conditions,the removal rate of nitro compounds reaches 68.4%at 100 min.The removal rate is maintained at approximately 68%after 4 cycles in RPB,but it is decreased substantially from 57.9%to 36.8%in a stirred tank reactor.This is because RPB can increase the specific surface area and the renewal of the liquid–solid interface,and as a result the degradation efficiency of Fe–C micro-electrolysis is improved and the active sites on the Fe–C surface can be regenerated for continuous use.In conclusion,high-gravity intensified Fe–C micro-electrolysis can weaken the passivation of Fe–C particles and extend their service life.展开更多
The packing densification of binary spherical mixtures under 3D mechanical vibration was studied experimentally. The influences of vibration frequency （ω）, volume fraction of large spheres （XL）, sphere size ratio...The packing densification of binary spherical mixtures under 3D mechanical vibration was studied experimentally. The influences of vibration frequency （ω）, volume fraction of large spheres （XL）, sphere size ratio （r, diameter ratio of small to large spheres）, and container size （D） on the random binary packing density （p） were systematically analyzed. For any given set of conditions, there exist optimal ω and XL to realize the densest random binary packing; too large or small ω and XL is not helpful for densification. The influences of both r and D on p are monotonic; either reducing r or increasing D leads to a high value of p. With all other parameters held constant, the densest random packing occurs when XL is dominant, which is in good agreement with the Furnas relation. Moreover, the highest random binary packing density obtained in our work agrees well with corresponding numerical and analytical results in the literature.展开更多
基金financially supported by the Guangdong Provincial Key Laboratory of Functional and Intelligent Hybrid Materials and Devices(No.2019B121203003)the Recruitment Program of Guangdong(No.2016ZT06C322)Major Program of National Natural Science Foundation of China(No.51890871)。
文摘The construction of complex superlattices using homogenous soft matter has great potential for the bottom-up fabrication of complex,nanoscale structures.This topic is not only interested in scientific exploring for new concepts of supramolecular crystals with nanometer in sizes,which is about thousand times larger in volumes than those of normal crystals,but also practically important to provide construction principles of metamaterials which are artificially structured materials for controlling and manipulating light,sound,and other physical behaviors.These systems have fast assembly kinetics and convenient processing procedures,making them ideal for large-scale superlattice production.In this perspective,we focus on recent developments in the construction of complex spherical packing superlattices using homogenous soft self-assemblies.We discuss the general mechanism of those formations of supramolecular motifs and provide an overview of the spherical packing superlattices self-assembled by homogenous soft matters based on different volume asymmetry.Additionally,we outline the potentials of utilizing this approach in constructing novel superlattices as well as its future challenges.
基金funded by the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)-Project-ID 422037413-TRR 287.Peter Kovats and our student Zahin Thamed are acknowledged for their help during experiments.
文摘Ray tracing Particle Image Velocimetry(RT-PIV)is an optical technique for high resolution velocity measurements in challenging optical systems,such as transparent packed beds,that uses ray tracing to correct for distortions introduced by transparent geometries in the light paths.The ray tracing based correction is a post processing step applied to the raw PIV particle images before classical PIV evaluation.In this study,RT-PIV is performed in the top layer of a body centred cubic(bcc)sphere packing with gaseous flow,where optical access is obtained by the use of transparent N-BK7 glass balls with a diameter of d=40 mm.RT-PIV introduces new experimental and numerical challenges,for example a limited field of view,illumination difficulties,a very large required depth of field and high sensitivity to geometric parameters used in the ray tracing correction.These challenges and their implications are the main scope and discussed in the present work.Further,the validation of the ray tracing reconstruction step is presented and examples for the obtained corrected vector fields in a packed bed are given.The results show the strength of the method in reconstructing velocity fields behind transparent spheres that would not have been accessible by optical measurement techniques without the ray tracing correction.
基金This work was supported by the Fund for Shanxi"1331Project"(Grant No.nuc2021-006),Scientific Activities of Selected Returned Overseas Professionals in Shanxi Province(Grant No.20200004)Shanxi Scholarship Council of China(Grant No.2019032).
文摘The application of iron–carbon(Fe–C)micro-electrolysis to wastewater treatment is limited by the passivation potential of the Fe–C packing.In order to address this problem,high-gravity intensified Fe–C micro-electrolysis was proposed in this study for degradation of dinitrotoluene wastewater in a rotating packed bed(RPB)using commercial Fe–C particles as the packing.The effects of reaction time,high-gravity factor,liquid flow rate and initial solution pH were investigated.The degradation intermediates were determined by gas chromatography-mass spectrometry,and the possible degradation pathways of nitro compounds by Fe–C micro-electrolysis in RPB were also proposed.It is found that under optimal conditions,the removal rate of nitro compounds reaches 68.4%at 100 min.The removal rate is maintained at approximately 68%after 4 cycles in RPB,but it is decreased substantially from 57.9%to 36.8%in a stirred tank reactor.This is because RPB can increase the specific surface area and the renewal of the liquid–solid interface,and as a result the degradation efficiency of Fe–C micro-electrolysis is improved and the active sites on the Fe–C surface can be regenerated for continuous use.In conclusion,high-gravity intensified Fe–C micro-electrolysis can weaken the passivation of Fe–C particles and extend their service life.
文摘The packing densification of binary spherical mixtures under 3D mechanical vibration was studied experimentally. The influences of vibration frequency （ω）, volume fraction of large spheres （XL）, sphere size ratio （r, diameter ratio of small to large spheres）, and container size （D） on the random binary packing density （p） were systematically analyzed. For any given set of conditions, there exist optimal ω and XL to realize the densest random binary packing; too large or small ω and XL is not helpful for densification. The influences of both r and D on p are monotonic; either reducing r or increasing D leads to a high value of p. With all other parameters held constant, the densest random packing occurs when XL is dominant, which is in good agreement with the Furnas relation. Moreover, the highest random binary packing density obtained in our work agrees well with corresponding numerical and analytical results in the literature.
