Nitrogen(N)deep placement has been found to reduce N leaching and increase N use efficiency in paddy fields.However,relatively little is known how bacterial consortia,especially abundant and rare taxa,respond to N dee...Nitrogen(N)deep placement has been found to reduce N leaching and increase N use efficiency in paddy fields.However,relatively little is known how bacterial consortia,especially abundant and rare taxa,respond to N deep placement,which is critical for understanding the biodiversity and function of agricultural ecosystem.In this study,lllumina sequencing and ecological models were conducted to examine the diversity patterns and underlying assembly mechanisms of abundant and rare taxa in rice rhizosphere soil under different N fertilization regimes at four rice growth stages in paddy fields.The results showed that abundant and rare bacteria had distinct distribution patterns in rhizosphere samples.Abundant bacteria showed ubiquitous distribution;while rare taxa exhibited uneven distribution across all samples.Stochastic processes dominated community assembly of both abundant and rare bacteria,with dispersal limitation playing a more vital role in abundant bacteria,and undominated processes playing a more important role in rare bacteria.The N deep placement was associated with a greater influence of dispersal limitation than the broadcast N fertilizer(BN)and no N fertilizer(NN)treatments in abundant and rare taxa of rhizosphere soil;while greater contributions from homogenizing dispersal were observed for BN and NN in rare taxa.Network analysis indicated that abundant taxa with closer relationships were usually more likely to occupy the central position of the network than rare taxa.Nevertheless,most of the keystone species were rare taxa and might have played essential roles in maintaining the network stability.Overall,these findings highlighted that the ecological mechanisms and co-occurrence patterns of abundant and rare bacteria in rhizosphere soil under N deep placement.展开更多
With the latest information on geology, isotop chronology, geochemistry and aerial geophysics, the structural enviroment, geological event characterists and evolution history of component units of Rodinia Supercontine...With the latest information on geology, isotop chronology, geochemistry and aerial geophysics, the structural enviroment, geological event characterists and evolution history of component units of Rodinia Supercontinent on a global scale are discussed. And some neo views and genetic pattern are provided. The East Eurppean Craton had a complex evolution history between 1.7 and 0.9 Ga. The arthors propose a new reconstruction of Laurentia acient land and Siberia at ca. 1 050～1 000 Ma. The largest litho-structural record of the Meso-Neoproterozoic orogenic collage in South America made up the western border of the South American Platform African Cratons are the result of convergence of Paleoproterozoic/Archaem Cratonic blocks. A part of Eastern Antarctica attached to southern Africa in Mesoproterozoic. Neoproterozoic felsic magmatic events in New India made the western border of Rodinia Pre-Grevoillian Laurentia was established as a major continental block by the end of the Paleoproterozoic. South China is geologically plausible to be between southern Laurentia and eastern Australia. Yangzi-Tarim connection or neighborhood is proposed. According to the abovementionded, the assembly and breakup paattern of Rodinia proposed by Pisarevsky is tested. It telles that primary break up is along the western border of Laurentia ancient land, which is similar to northern Atlantic. Another characteristic is that some continents are not considered as component parts of Rodinia, eg. India, Congo and San-Francisco.展开更多
Modular continuum robots possess significant versatility across various scenarios;however,conventional assembling methods typically rely on linear connection between modules.This limitation can impede the robotic inte...Modular continuum robots possess significant versatility across various scenarios;however,conventional assembling methods typically rely on linear connection between modules.This limitation can impede the robotic interaction capabilities,especially in specific engineering applications.Herein,inspired by the assembling pattern between the femur and tibia in a human knee,we proposed a multidirectional assembling strategy.This strategy encompasses linear,oblique,and orthogonal connections,allowing a two-module continuum robot to undergo in-situ reconfiguration into three distinct initial configurations.To anticipate the final configuration resulting from diverse assembling patterns,we employed the positional formulation finite element framework to establish a mechanical model,and the theoretical results reveal that our customizable strategy can offer an effective route for robotic interactions.We showcased diverse assembling patterns for coping with interaction requirements.The experimental results indicate that our modular continuum robot not only reconfigures its initial profile in situ but also enables on-demand regulation of the final configuration.These capabilities provide a foundation for the future development of modular continuum robots,enabling them to be adaptable to diverse environments,particularly in unstructured surroundings.展开更多
Based on a brief review of the traditional surface patterning research, this article introduces the recent progress in the research on surface patterning via molecular self-assembly. Because the size scale of molecula...Based on a brief review of the traditional surface patterning research, this article introduces the recent progress in the research on surface patterning via molecular self-assembly. Because the size scale of molecular self-assemblies is in the range of 1-100 nm, the method of molecular self-assembly can easily lead to the construction of ordered structures in nanometer scale, and thus break through the size limit of traditional lithography. Some novel ways of molecular self-assembly for surface patterning are particularly introduced in this review, including supramo-lecular architecture at interface, chemisorption of dendron thoils, and surface aggregation of bolaform amphiphiles. Provided that we know more and more about the basic principles governing the surface morphology, it is believed that interfacial molecular assembly would be a very competitive supramolecular technique, and a potential application in many fields such as surface property adjustment, organic patterned devices, surface molecular展开更多
Spherical nanostructures with striped patterns on the surfaces resembling the essential structures of natural virus particles were constructed through a two-step self-assembly approach of polystyrene-boligo（acrylic a...Spherical nanostructures with striped patterns on the surfaces resembling the essential structures of natural virus particles were constructed through a two-step self-assembly approach of polystyrene-boligo（acrylic acid）（PS-b-oligo-AA） and poly（γ-benzyI L-glutamate）-b-poly（ethylene glycol）（PBLG-bPEG） copolymer mixtures in solution.On the basis of difference in hydrophilicity and self-assembly properties of the two copolymers,the two-step self-assembly process is realized.It was found that PS-boligo-AA copolymers formed spherical aggregates by adding a certain amount of water into polymer solutions in the first step.In the second step,two polymer solutions were mixed and water was further added,inducing the self-assembly of PBLG-b-PEG on the surfaces of PS-b-oligo-AA spheres to form striped patterns.In-depth study was conducted for the indispensable defects of striped patterns which are dislocations and ＋1/2 disclinations.The influencing factors such as the mixing ratio of two copolymers and the added water content in the first step on the morphology and defects of the striped patterns were investigated.This work not only presents an idea to interpret mechanism of the cooperative self-assembly behavior,but also provides an effective approach to construct virus-like particles and other complex structures with controllable morphology.展开更多
Self-assembly of polystyrene spheres guided by patterned n-type InP substrates has been investigated. InP surfaces were patterned using a variety of methods including wet chemical etching,sputter coating,thermal evapo...Self-assembly of polystyrene spheres guided by patterned n-type InP substrates has been investigated. InP surfaces were patterned using a variety of methods including wet chemical etching,sputter coating,thermal evaporation,and photo lithography. The self-assembly of polystyrene spheres depended on the appearance of patterns and was affected by the deposition techniques (sputter coating and thermal evaporation) of Au micro-squares. SEM and AFM were used to characterize the surface morphologies.展开更多
Self assembled monolayers(SAMs) based on a novel dendron thiols system, which maintain the alkanethiols active site, but the —SH group connected with independently variable groups by a dendron linker, showed the co...Self assembled monolayers(SAMs) based on a novel dendron thiols system, which maintain the alkanethiols active site, but the —SH group connected with independently variable groups by a dendron linker, showed the controllable surface pattern and wetting property. The precisely tailored structure of dendron thiols with local controlled hydrophobic and hydrophilic peripheries allow the formation of designed surface structures on gold surface, e.g. nano stripes, honeycomb and homogeneous structure.展开更多
基金the National Key Research and Development Program of China(2016YFD0200309 and 2018YFD0301104-01).
文摘Nitrogen(N)deep placement has been found to reduce N leaching and increase N use efficiency in paddy fields.However,relatively little is known how bacterial consortia,especially abundant and rare taxa,respond to N deep placement,which is critical for understanding the biodiversity and function of agricultural ecosystem.In this study,lllumina sequencing and ecological models were conducted to examine the diversity patterns and underlying assembly mechanisms of abundant and rare taxa in rice rhizosphere soil under different N fertilization regimes at four rice growth stages in paddy fields.The results showed that abundant and rare bacteria had distinct distribution patterns in rhizosphere samples.Abundant bacteria showed ubiquitous distribution;while rare taxa exhibited uneven distribution across all samples.Stochastic processes dominated community assembly of both abundant and rare bacteria,with dispersal limitation playing a more vital role in abundant bacteria,and undominated processes playing a more important role in rare bacteria.The N deep placement was associated with a greater influence of dispersal limitation than the broadcast N fertilizer(BN)and no N fertilizer(NN)treatments in abundant and rare taxa of rhizosphere soil;while greater contributions from homogenizing dispersal were observed for BN and NN in rare taxa.Network analysis indicated that abundant taxa with closer relationships were usually more likely to occupy the central position of the network than rare taxa.Nevertheless,most of the keystone species were rare taxa and might have played essential roles in maintaining the network stability.Overall,these findings highlighted that the ecological mechanisms and co-occurrence patterns of abundant and rare bacteria in rhizosphere soil under N deep placement.
文摘With the latest information on geology, isotop chronology, geochemistry and aerial geophysics, the structural enviroment, geological event characterists and evolution history of component units of Rodinia Supercontinent on a global scale are discussed. And some neo views and genetic pattern are provided. The East Eurppean Craton had a complex evolution history between 1.7 and 0.9 Ga. The arthors propose a new reconstruction of Laurentia acient land and Siberia at ca. 1 050～1 000 Ma. The largest litho-structural record of the Meso-Neoproterozoic orogenic collage in South America made up the western border of the South American Platform African Cratons are the result of convergence of Paleoproterozoic/Archaem Cratonic blocks. A part of Eastern Antarctica attached to southern Africa in Mesoproterozoic. Neoproterozoic felsic magmatic events in New India made the western border of Rodinia Pre-Grevoillian Laurentia was established as a major continental block by the end of the Paleoproterozoic. South China is geologically plausible to be between southern Laurentia and eastern Australia. Yangzi-Tarim connection or neighborhood is proposed. According to the abovementionded, the assembly and breakup paattern of Rodinia proposed by Pisarevsky is tested. It telles that primary break up is along the western border of Laurentia ancient land, which is similar to northern Atlantic. Another characteristic is that some continents are not considered as component parts of Rodinia, eg. India, Congo and San-Francisco.
基金supported by the Shenzhen Science and Technology Program(Grant No.20220817165030002,No.GXWD2021B03)National Natural Science Foundation of China(Grant No.52275298 and No.11922203).
文摘Modular continuum robots possess significant versatility across various scenarios;however,conventional assembling methods typically rely on linear connection between modules.This limitation can impede the robotic interaction capabilities,especially in specific engineering applications.Herein,inspired by the assembling pattern between the femur and tibia in a human knee,we proposed a multidirectional assembling strategy.This strategy encompasses linear,oblique,and orthogonal connections,allowing a two-module continuum robot to undergo in-situ reconfiguration into three distinct initial configurations.To anticipate the final configuration resulting from diverse assembling patterns,we employed the positional formulation finite element framework to establish a mechanical model,and the theoretical results reveal that our customizable strategy can offer an effective route for robotic interactions.We showcased diverse assembling patterns for coping with interaction requirements.The experimental results indicate that our modular continuum robot not only reconfigures its initial profile in situ but also enables on-demand regulation of the final configuration.These capabilities provide a foundation for the future development of modular continuum robots,enabling them to be adaptable to diverse environments,particularly in unstructured surroundings.
基金This work was supported by the State Major Basic Research & Development Program (Grant No. G2000078102) the National Natural Science Foundation of China (Grant Nos. 20074014 and 59928303).
文摘Based on a brief review of the traditional surface patterning research, this article introduces the recent progress in the research on surface patterning via molecular self-assembly. Because the size scale of molecular self-assemblies is in the range of 1-100 nm, the method of molecular self-assembly can easily lead to the construction of ordered structures in nanometer scale, and thus break through the size limit of traditional lithography. Some novel ways of molecular self-assembly for surface patterning are particularly introduced in this review, including supramo-lecular architecture at interface, chemisorption of dendron thoils, and surface aggregation of bolaform amphiphiles. Provided that we know more and more about the basic principles governing the surface morphology, it is believed that interfacial molecular assembly would be a very competitive supramolecular technique, and a potential application in many fields such as surface property adjustment, organic patterned devices, surface molecular
基金supported by the National Natural Science Foundation of China(Nos.21234002,51303055,21474029,and51573049)Support from projects of Shanghai municipality(Nos.15QA1401400 and 13JC1402000)
文摘Spherical nanostructures with striped patterns on the surfaces resembling the essential structures of natural virus particles were constructed through a two-step self-assembly approach of polystyrene-boligo（acrylic acid）（PS-b-oligo-AA） and poly（γ-benzyI L-glutamate）-b-poly（ethylene glycol）（PBLG-bPEG） copolymer mixtures in solution.On the basis of difference in hydrophilicity and self-assembly properties of the two copolymers,the two-step self-assembly process is realized.It was found that PS-boligo-AA copolymers formed spherical aggregates by adding a certain amount of water into polymer solutions in the first step.In the second step,two polymer solutions were mixed and water was further added,inducing the self-assembly of PBLG-b-PEG on the surfaces of PS-b-oligo-AA spheres to form striped patterns.In-depth study was conducted for the indispensable defects of striped patterns which are dislocations and ＋1/2 disclinations.The influencing factors such as the mixing ratio of two copolymers and the added water content in the first step on the morphology and defects of the striped patterns were investigated.This work not only presents an idea to interpret mechanism of the cooperative self-assembly behavior,but also provides an effective approach to construct virus-like particles and other complex structures with controllable morphology.
基金Supported by the Notional Natural Science Foundation of China (Grant No. 50672089)the Encouraging Foundation for the Scientific Research of the Excel-lent Young and Middle-aged Scientists in Shandong Province of China (Grant No. 2006BS04034)
文摘Self-assembly of polystyrene spheres guided by patterned n-type InP substrates has been investigated. InP surfaces were patterned using a variety of methods including wet chemical etching,sputter coating,thermal evaporation,and photo lithography. The self-assembly of polystyrene spheres depended on the appearance of patterns and was affected by the deposition techniques (sputter coating and thermal evaporation) of Au micro-squares. SEM and AFM were used to characterize the surface morphologies.
文摘Self assembled monolayers(SAMs) based on a novel dendron thiols system, which maintain the alkanethiols active site, but the —SH group connected with independently variable groups by a dendron linker, showed the controllable surface pattern and wetting property. The precisely tailored structure of dendron thiols with local controlled hydrophobic and hydrophilic peripheries allow the formation of designed surface structures on gold surface, e.g. nano stripes, honeycomb and homogeneous structure.
