Projection micro stereolithography(PμSL)has emerged as a powerful three-dimensional(3D)printing technique for manufacturing polymer structures with micron-scale high resolution at high printing speed,which enables th...Projection micro stereolithography(PμSL)has emerged as a powerful three-dimensional(3D)printing technique for manufacturing polymer structures with micron-scale high resolution at high printing speed,which enables the production of customized 3D microlattices with feature sizes down to several microns.However,the mechanical properties of as-printed polymers were not systemically studied at the relevant length scales,especially when the feature sizes step into micron/sub-micron level,limiting its reliable performance prediction in micro/nanolattice and other metamaterial applications.In this work,we demonstrate that PμSL-printed microfibers could become stronger and significantly more ductile with reduced size ranging from 20μm to 60μm,showing an obvious size-dependent mechanical behavior,in which the size decreases to 20μm with a fracture strain up to~100%and fracture strength up to~100 MPa.Such size effect enables the tailoring of the material strength and stiffness of PμSL-printed microlattices over a broad range,allowing to fabricate the microlattice metamaterials with desired/tunable mechanical properties for various structural and functional applications.展开更多
Current electronic technology based on silicon is approaching its physical and scientific limits. Carbon-based devices have numer- ous advantages for next generation electronics (e.g., fast speed, low power consumptio...Current electronic technology based on silicon is approaching its physical and scientific limits. Carbon-based devices have numer- ous advantages for next generation electronics (e.g., fast speed, low power consumption and simple process), that when combined with the unique nature of the versatile allotropes of carbon elements, are creating an electronics revolution. Carbon electronics are greatly advancing with new preparations and sophisticated designs. In this perspective, representatives with various dimensions, e.g., carbon nanotubes, graphene, bulk diamond, and their extraordinary performance, are reviewed. The associated state-of-the-art devices and composite hybrid all-carbon structures are also emphasized to reveal their potential in the electronics field. Advances in commercial production have improved the cost effi-ciency, material quality, and device design, accelerating the promise of carbon materials.展开更多
[Objectives]To understand the content changes of fatty acid compositions and seedling growths during seed germinations of Cassia obtusifolia L.[Methods]The fatty acid compositions of germinations and seedling growths ...[Objectives]To understand the content changes of fatty acid compositions and seedling growths during seed germinations of Cassia obtusifolia L.[Methods]The fatty acid compositions of germinations and seedling growths of C.obtusifolia seeds treated with different concentrations of gibberellin(GA3)and naphthalene acetic acid(NAA)were analyzed using gas chromatograph-mass spectrometer(GC-MS),and the germination rates,root lengths,plant heights and fresh weights of their seedlings were analyzed.[Results]The contents of eicosenoic acid,α-linoleic acid,arachidic acid,eicosadienoic acid and eicosapentaenoic acid of C.obtusifolia seeds treated with different concentrations of GA3 and NAA decreased with germination time.There were significant differences between the ratios of germinations of C.obtusifolia seeds treated with different concentrations of GA3 and NAA.GA3 and NAA of different ratio treatments could promote seedling heights and fresh weights of C.obtusifolia,but increases of seedling heights and fresh weights were different.Eicosenoic acid,α-linoleic acid,arachidic acid,eicosadienoic acid and eicosapentaenoic acid were remarkably negative correlation with seedling heights and fresh weights.[Conclusions]The fatty acid components of C.obtusifolia seed germination and growth of their seedlings were affected.It indicated that GA3 and NAA treatments can affect fatty acid metabolism,the germination rates,root lengths,plant heights and fresh weights of C.obtusifolia.It is intended to provide a theoretical basis and technological reference for standardized cultivated techniques of C.obtusifolia.展开更多
Three-dimensional(3D)vertical architecture transistors represent an important technological pursuit,which have distinct advantages in device integration density,operation speed,and power consumption.However,the fabric...Three-dimensional(3D)vertical architecture transistors represent an important technological pursuit,which have distinct advantages in device integration density,operation speed,and power consumption.However,the fabrication processes of such 3D devices are complex,especially in the interconnection of electrodes.In this paper,we present a novel method which combines suspended electrodes and focused ion beam(FIB)technology to greatly simplify the electrodes interconnection in 3D devices.Based on this method,we fabricate 3D vertical core-double shell structure transistors with ZnO channel and Al_(2)O_(3) gate-oxide both grown by atomic layer deposition.Suspended top electrodes of vertical architecture could be directly connected to planar electrodes by FIB deposited Pt nanowires,which avoid cumbersome steps in the traditional 3D structure fabrication technology.Both single pillar and arrays devices show well behaved transfer characteristics with an Ion/Ioff current ratio greater than 106 and a low threshold voltage around 0 V.The ON-current of the 2×2 pillars vertical channel transistor was 1.2μA at the gate voltage of 3 V and drain voltage of 2 V,which can be also improved by increasing the number of pillars.Our method for fabricating vertical architecture transistors can be promising for device applications with high integration density and low power consumption.展开更多
[Objectives]To study responses of Houttuynia cordata Thunb.to tetracycline(TC)stress in a sterile environment.[Methods]Aseptic H.cordata seedlings were cultured in the medium which added the different concentrations o...[Objectives]To study responses of Houttuynia cordata Thunb.to tetracycline(TC)stress in a sterile environment.[Methods]Aseptic H.cordata seedlings were cultured in the medium which added the different concentrations of TC,and then the contents of chlorophyll and malondialdehyde(MDA),and activity of catalase(CAT),peroxidase(POD)and superoxide dismutase(SOD)of H.cordata leaves were measured.[Results]Compared with the CK,the contents of chlorophyll of H.cordata leaves decreased,and the accumulation of MDA,and the activity of CAT,POD and SOD in H.cordata leaves increased when H.cordata was stressed by different concentration of TC.[Conclusions]The growth,metabolism and physiology of H.cordata were affected by the stress of TC.More importantly,this proved an insight into the effect or harm of undegraded antibiotics in the soil and water in the natural environment to plant growth all the time.展开更多
Phytohormones play important roles in orchestrating plantimmune responses to pathogen attacks.Strigolactones(SLs),a group of carotenoid-derived phytohormones,modulate diverse biological processes in plants,including s...Phytohormones play important roles in orchestrating plantimmune responses to pathogen attacks.Strigolactones(SLs),a group of carotenoid-derived phytohormones,modulate diverse biological processes in plants,including shoot branching,plant height,root architecture,leaf senescence,seed germination of parasitic plants,and symbiosis of arbuscular mycorrhizal fungi(Burger and Chory,2020).Recently,increasing evidence has indicated potential roles for SLs in regulating responses against biotic stresses,including defense responses against certain pathogenic fungi and bacteria in roots and leaves(Yi et al.,2023).展开更多
Origami structure has been employed in many engineering applications.However,there is currently no strategy that can systematically achieve stiffness-tunable origami(STO)structures through proper geometric design.Here...Origami structure has been employed in many engineering applications.However,there is currently no strategy that can systematically achieve stiffness-tunable origami(STO)structures through proper geometric design.Here,we report a strategy for designing and fabricating STO structures based on thick-panel origami using multimaterial 3D printing.By adjusting the soft hinge position,we tune the geometric parameterψto program the stiffness and strength of origami structures.We develop origami structures with graded stiffness and strength by stacking Kresling origami structures with differentψ.The printed structures show great cyclic characteristics and deformation ability.After optimizing combinations of structures with differentψ,the multi-layer Kresling STO structures can effectively reduce the peak impact,showing a good energy absorption effect.The proposed approach can be implemented in various origami patterns to design and tune the mechanical properties of origami structures for many potential applications.展开更多
Chemical vapor deposited(CVD)diamond as a burgeoning multifunctional material with tailored quality and characteristics can be artificially synthesized and controlled for various applications.Correspondingly,the appli...Chemical vapor deposited(CVD)diamond as a burgeoning multifunctional material with tailored quality and characteristics can be artificially synthesized and controlled for various applications.Correspondingly,the application-related“grade”concept associated with materials choice and design was gradually formulated,of which the availability and the performance are optimally suited.In this review,the explicit diversity of CVD diamond and the clarification of typical grades for applications,i.e.,from resplendent gem-grade to promising quantum-grade,were systematically summarized and discussed,according to the crystal quality and main consideration of ubiquitous nitrogen impurity content as well as major applications.Realizations of those,from quantum-grade with near-ideal crystal to electronic-grade having extremely low imperfections and then to optical,thermal as well as mechanical-grade needing controlled flaws and allowable impurities,would competently fulfill the multi-field application prospects with appropriate choice in terms of cost and quality.Exceptionally,wide range defects and impurities in the gem-grade diamond(only indicating single crystal),which are detrimental for technology applications,endows CVD crystals with fancy colors to challenge their natural counterparts.展开更多
基金the financial support from Shenzhen Science and Technology Innovation Committee under the Grant Nos. JCYJ20170818103206501, Type C 202011033000145Changsha Municipal Science and Technology Bureau Project kh2201035supported by the City University of Hong Kong under the Grant No. 9667226
文摘Projection micro stereolithography(PμSL)has emerged as a powerful three-dimensional(3D)printing technique for manufacturing polymer structures with micron-scale high resolution at high printing speed,which enables the production of customized 3D microlattices with feature sizes down to several microns.However,the mechanical properties of as-printed polymers were not systemically studied at the relevant length scales,especially when the feature sizes step into micron/sub-micron level,limiting its reliable performance prediction in micro/nanolattice and other metamaterial applications.In this work,we demonstrate that PμSL-printed microfibers could become stronger and significantly more ductile with reduced size ranging from 20μm to 60μm,showing an obvious size-dependent mechanical behavior,in which the size decreases to 20μm with a fracture strain up to~100%and fracture strength up to~100 MPa.Such size effect enables the tailoring of the material strength and stiffness of PμSL-printed microlattices over a broad range,allowing to fabricate the microlattice metamaterials with desired/tunable mechanical properties for various structural and functional applications.
基金the National Key Research and Development Program of China(No.2016YFE0133200)National Natural Science Foundation of China(No.52172037)+4 种基金European Union’s Horizon 2020 Research and Innovation Staff Exchange Scheme(No.734578)Post-doctor Research Foundation of Shunde Graduate School of University of Science and Technology Beijing(No.2021 BH006)Beijing Municipal Natural Science Foundation(Nos.2212036 and 4192038)Science and Technology Innovation Special Project of Foshan Government(Nos.BK20BE021 and BK21BE004)Special thanks to the nation-al high-level-university sponsored graduate program of China Scholarship Council(CSC),USTB-Monte Biance Joint R&D Center and joint-postdoc research program of Shunde Graduate School of USTB.
文摘Current electronic technology based on silicon is approaching its physical and scientific limits. Carbon-based devices have numer- ous advantages for next generation electronics (e.g., fast speed, low power consumption and simple process), that when combined with the unique nature of the versatile allotropes of carbon elements, are creating an electronics revolution. Carbon electronics are greatly advancing with new preparations and sophisticated designs. In this perspective, representatives with various dimensions, e.g., carbon nanotubes, graphene, bulk diamond, and their extraordinary performance, are reviewed. The associated state-of-the-art devices and composite hybrid all-carbon structures are also emphasized to reveal their potential in the electronics field. Advances in commercial production have improved the cost effi-ciency, material quality, and device design, accelerating the promise of carbon materials.
基金Supported by the National Natural Science Foundation of China(41761010&81260641)Science and Technology Foundation of Guizhou province of China([2017]1121)the Project of Scientific Research of Doctors of Guizhou Normal University.
文摘[Objectives]To understand the content changes of fatty acid compositions and seedling growths during seed germinations of Cassia obtusifolia L.[Methods]The fatty acid compositions of germinations and seedling growths of C.obtusifolia seeds treated with different concentrations of gibberellin(GA3)and naphthalene acetic acid(NAA)were analyzed using gas chromatograph-mass spectrometer(GC-MS),and the germination rates,root lengths,plant heights and fresh weights of their seedlings were analyzed.[Results]The contents of eicosenoic acid,α-linoleic acid,arachidic acid,eicosadienoic acid and eicosapentaenoic acid of C.obtusifolia seeds treated with different concentrations of GA3 and NAA decreased with germination time.There were significant differences between the ratios of germinations of C.obtusifolia seeds treated with different concentrations of GA3 and NAA.GA3 and NAA of different ratio treatments could promote seedling heights and fresh weights of C.obtusifolia,but increases of seedling heights and fresh weights were different.Eicosenoic acid,α-linoleic acid,arachidic acid,eicosadienoic acid and eicosapentaenoic acid were remarkably negative correlation with seedling heights and fresh weights.[Conclusions]The fatty acid components of C.obtusifolia seed germination and growth of their seedlings were affected.It indicated that GA3 and NAA treatments can affect fatty acid metabolism,the germination rates,root lengths,plant heights and fresh weights of C.obtusifolia.It is intended to provide a theoretical basis and technological reference for standardized cultivated techniques of C.obtusifolia.
基金the National Key Research and Development Program of China(Grant Nos.2016YFA0200400 and 2016YFA0200800)the National Natural Science Foundation of China(Grant Nos.61888102,12074420,and 11674387)+1 种基金Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB33000000)Key Research Program of Frontier Sciences,Chinese Acdemy of Sciences(Grant No.QYZDJ-SSWSLH042).
文摘Three-dimensional(3D)vertical architecture transistors represent an important technological pursuit,which have distinct advantages in device integration density,operation speed,and power consumption.However,the fabrication processes of such 3D devices are complex,especially in the interconnection of electrodes.In this paper,we present a novel method which combines suspended electrodes and focused ion beam(FIB)technology to greatly simplify the electrodes interconnection in 3D devices.Based on this method,we fabricate 3D vertical core-double shell structure transistors with ZnO channel and Al_(2)O_(3) gate-oxide both grown by atomic layer deposition.Suspended top electrodes of vertical architecture could be directly connected to planar electrodes by FIB deposited Pt nanowires,which avoid cumbersome steps in the traditional 3D structure fabrication technology.Both single pillar and arrays devices show well behaved transfer characteristics with an Ion/Ioff current ratio greater than 106 and a low threshold voltage around 0 V.The ON-current of the 2×2 pillars vertical channel transistor was 1.2μA at the gate voltage of 3 V and drain voltage of 2 V,which can be also improved by increasing the number of pillars.Our method for fabricating vertical architecture transistors can be promising for device applications with high integration density and low power consumption.
基金National Natural Science Foundation of China(41761010)Science and Technology Foundation of Guizhou Province of China(Qian Ke He Ji Chu[2017]1121).
文摘[Objectives]To study responses of Houttuynia cordata Thunb.to tetracycline(TC)stress in a sterile environment.[Methods]Aseptic H.cordata seedlings were cultured in the medium which added the different concentrations of TC,and then the contents of chlorophyll and malondialdehyde(MDA),and activity of catalase(CAT),peroxidase(POD)and superoxide dismutase(SOD)of H.cordata leaves were measured.[Results]Compared with the CK,the contents of chlorophyll of H.cordata leaves decreased,and the accumulation of MDA,and the activity of CAT,POD and SOD in H.cordata leaves increased when H.cordata was stressed by different concentration of TC.[Conclusions]The growth,metabolism and physiology of H.cordata were affected by the stress of TC.More importantly,this proved an insight into the effect or harm of undegraded antibiotics in the soil and water in the natural environment to plant growth all the time.
基金supported by NSFC(32072043,32272116,32122012)Fok Ying Tung Education Foundation(171023)Sichuan Science and Technology Program(2023ZYD0086,2023NSFSC0155,2023NSFSC1937,2024NSFTD0022).
文摘Phytohormones play important roles in orchestrating plantimmune responses to pathogen attacks.Strigolactones(SLs),a group of carotenoid-derived phytohormones,modulate diverse biological processes in plants,including shoot branching,plant height,root architecture,leaf senescence,seed germination of parasitic plants,and symbiosis of arbuscular mycorrhizal fungi(Burger and Chory,2020).Recently,increasing evidence has indicated potential roles for SLs in regulating responses against biotic stresses,including defense responses against certain pathogenic fungi and bacteria in roots and leaves(Yi et al.,2023).
基金supported by the National KeyResearch and Development Program of China(2020YFB1312900)the National Natural Science Foundation of China(No.12072142)+1 种基金the Key Talent Recruitment Program of Guangdong Province(No.2019QN01Z438)the Science Technology and Innovation Commission of Shenzhen Municipality(ZDSYS20210623092005017).
文摘Origami structure has been employed in many engineering applications.However,there is currently no strategy that can systematically achieve stiffness-tunable origami(STO)structures through proper geometric design.Here,we report a strategy for designing and fabricating STO structures based on thick-panel origami using multimaterial 3D printing.By adjusting the soft hinge position,we tune the geometric parameterψto program the stiffness and strength of origami structures.We develop origami structures with graded stiffness and strength by stacking Kresling origami structures with differentψ.The printed structures show great cyclic characteristics and deformation ability.After optimizing combinations of structures with differentψ,the multi-layer Kresling STO structures can effectively reduce the peak impact,showing a good energy absorption effect.The proposed approach can be implemented in various origami patterns to design and tune the mechanical properties of origami structures for many potential applications.
基金This work was supported by the National Key Research and Development Program of China(Grant No.2016YFE0133200)the European Union’s Horizon 2020 Research and Innovation Staff Exchange Scheme(Grant No.734578)+6 种基金the Post-doctor Research Foundation of Shunde Graduate School of University of Science and Technology Beijing(Grant No.2021BH006)the National Natural Science Foundation of China(Grant No.52172037)the Beijing Municipal Natural Science Foundation(Grant Nos.2212036 and 4192038)the Fundamental Research Funds for the Central Universities(FRF-MP-20-49Z)the Science and Technology Innovation Special Project of Foshan Government(Grant Nos.BK20BE021 and BK21BE004)Special thanks to the Guangdong Basic and Applied Basic Research Foundation(Grant No.2021A1515110631)the national high-level-university sponsored graduate program of China Scholarship Council(CSC No.201806460089),USTB-Monte Biance Joint R&D Center.
文摘Chemical vapor deposited(CVD)diamond as a burgeoning multifunctional material with tailored quality and characteristics can be artificially synthesized and controlled for various applications.Correspondingly,the application-related“grade”concept associated with materials choice and design was gradually formulated,of which the availability and the performance are optimally suited.In this review,the explicit diversity of CVD diamond and the clarification of typical grades for applications,i.e.,from resplendent gem-grade to promising quantum-grade,were systematically summarized and discussed,according to the crystal quality and main consideration of ubiquitous nitrogen impurity content as well as major applications.Realizations of those,from quantum-grade with near-ideal crystal to electronic-grade having extremely low imperfections and then to optical,thermal as well as mechanical-grade needing controlled flaws and allowable impurities,would competently fulfill the multi-field application prospects with appropriate choice in terms of cost and quality.Exceptionally,wide range defects and impurities in the gem-grade diamond(only indicating single crystal),which are detrimental for technology applications,endows CVD crystals with fancy colors to challenge their natural counterparts.
