This research aims to explore the decoration of TiO_(2)substrates with silver nanoparticles as a means of enhancing the photocatalytic oxidation of organic compounds.The results show that decorated TiO_(2)substrates e...This research aims to explore the decoration of TiO_(2)substrates with silver nanoparticles as a means of enhancing the photocatalytic oxidation of organic compounds.The results show that decorated TiO_(2)substrates exhibit significantly higher photocatalytic activity in sunlight than undecorated substrates.Morphological analysis is performed,followed by optical and structural characterizations.Scanning electron microscopy analysis of the TiO_(2)reveals many nanotubular structures with particle sizes of∼134.4,148.8,and 132.7 nm at random locations.TiO_(2)is also found to have an absorbance range of 397.6 nm,from which it is known that the photocatalyst reacts in the presence of an ultraviolet source.From the Miller indices of the x-ray diffraction peaks,the preferred crystal orientation is found to be associated with a face-centered cubic structure with a crystallite size of 3.76 nm.Using these promising results,photocatalytic analysis is performed,revealing good degradation characteristics.This investigation reveals that TiO_(2)substrates coated with Ag nanoparticles possess significant potential for application in the photocatalytic oxidation of methylene blue dye,which is a crucial step toward establishing a cleaner environment.展开更多
Anti-phase domain defects easily form in the in-plane GaAs nanowires(NWs)grown on CMOS-compatiblegroup IV substrates,which makes it difficult to obtain GaAs NWs with a designed length and also leads to asignificant li...Anti-phase domain defects easily form in the in-plane GaAs nanowires(NWs)grown on CMOS-compatiblegroup IV substrates,which makes it difficult to obtain GaAs NWs with a designed length and also leads to asignificant limitation in the growth of high-quality in-plane GaAs NW networks on such substrates.Here,wereport on the selective area growth of anti-phase domain-free in-plane GaAs NWs and NW networks on Ge(111)substrates.Detailed structural studies confirm that the GaAs NW grown using a large pattern period and GaAsNW networks grown by adding the Sb are both high-quality pure zinc-blende single crystals free of stackingfaults,twin defects,and anti-phase domain defects.Room-temperature photoluminescence measurements show asubstantial improvement in crystal quality and good consistency and uniformity of the GaAs NW networks.Ourwork provides useful insights into the controlled growth of high-quality anti-phase domain-defects-free in-planeIII-V NWs and NW networks.展开更多
Constructed Wetlands (CWs) are currently one of the most promising techniques for wastewater treatment, having demonstrated their effectiveness. However, the choice of substrate particle size is critical to the smooth...Constructed Wetlands (CWs) are currently one of the most promising techniques for wastewater treatment, having demonstrated their effectiveness. However, the choice of substrate particle size is critical to the smooth operation of the process, as hydrodynamic constraints require a coarse particle size, whereas wastewater treatment recommends a fine particle size. This study investigates the suitability of laterite and shale as substrates of different sizes (1 - 3, 3 - 5 and 5 - 8 mm) in CWs for domestic wastewater treatment. The study was carried out in an experimental pilot plant consisting of 12 parallelepiped beds (C × C = 0.4 × 0.4 m2;H = 0.6 m) filled from bottom to top with 0.1 m of gravel and 0.4 m of shale or laterite of different grain sizes with two replications. During the six months of operation, plant biomass and stem diameter of Pennisetum purpureum used as vegetation in the CWs were determined. Raw and treated water were also sampled and analyzed for pollutants, including chemical oxygen demand (COD), biochemical oxygen demand (BOD5), total Kjedahl nitrogen (TKN), total phosphorus (TP), and total suspended solids (TSS), using International Organization for Standardization (ISO) analytical methods. P. purpureum developed much better in the CW beds lined with shale;plant biomass ranged from 13.8 to 14.7 kg/m2 and from 11.2 to 12.5 kg/m2 in the beds lined with shale and laterite, respectively, as did stump diameter, which ranged from 15.5 to 16.1 cm and from 11.10 to 12.7 cm, respectively. However, the highest values for biomass and stump diameter for each material were obtained in the beds lined with 1 - 3 mm geomaterials. Pollutant removal efficiencies were highest in the CWs lined with laterite and shale of 1 - 3 mm grain size (76.9% - 83% COD, 78% - 84.7% BOD5, 55.5% - 72.2% TKN, 58.4% - 72.4% TP, 78.1% - 80.2% TSS), with the highest values recorded in the shale-lined beds. However, the 3 - 5 mm grain size of both materials provided quality filtrates (140 - 174 mg/L COD, 78.5 - 94.8 mg/L BOD5, 4.6 - 5.7 mg/L TP) in line with local wastewater discharge levels. This size of geomaterials appears to be suitable for optimization purposes, although further work with these materials, such as increasing the depth of the wetland, is required to improve the level of NTK and TSS discharge.展开更多
Laser etching and laser chemical vapor deposition(LCVD)techniques were proposed for the rapid preparation of high-purity,strongly bonded SiC porous micro-nano-coatings on quartz substrates.The laser serves as an exter...Laser etching and laser chemical vapor deposition(LCVD)techniques were proposed for the rapid preparation of high-purity,strongly bonded SiC porous micro-nano-coatings on quartz substrates.The laser serves as an external driving force for the vertical growth of SiC whiskers,facilitating the formation of a porous nanostructure that resembles coral models found in the macroscopic biological world.The porous nanostructures are beneficial for reducing thermal expansion mismatch and relieving residual stress.It is capable of eliminating the cracks on the surface of SiC coatings as well as enhancing the bonding of SiC coatings with quartz substrates to avoid coating detachment.展开更多
The influence of the electronic and steric properties of bromoaromatic substrates on direct arylation polymerization for synthesizing high-molecular-weight conjugated polymers was investigated through a combination of...The influence of the electronic and steric properties of bromoaromatic substrates on direct arylation polymerization for synthesizing high-molecular-weight conjugated polymers was investigated through a combination of experiments and calculations.Bromo-aromatic substrates with electron-withdrawing fluoro substituents exhibited higher yields and degrees of polymerization under PPh3-assisted conditions compared to those with electron-donating or bulky methyl substituents.Additionally,excessive steric hindrance at ortho-sites or overly electrondeficient dibromoaromatic substrates leads to reaction inactivation.Calculations indicated that electron-withdrawing substituents enhanced the electrophilicity of arylpalladium-PPh3intermediates,facilitating the activation of electron-rich arylative substrates and promoting polymer growth.Furthermore,steric hindrance from the substituents can influence the preferred reaction pathway,thereby increasing the real reaction barriers.Both experimental and computational results suggest that bromoaromatic substrates with optimized electron-deficient characteristics significantly improve monomer conversion and polymerization efficiency with n-hexylmethylether-substituted EDOT.These findings clarify how the electronic and steric properties of bromo-aromatic substrates affect EDOT derivative activation and are expected to aid in optimizing the polymerization conditions for the preparation of high-molecular-weight conjugated polymers.展开更多
Organisms have evolved a strain limiting mechanism,reflected as a non-linear elastic constitutive,to prevent large deformations from threatening soft tissue integrity.Compared with linear elastic substrates,the wrinkl...Organisms have evolved a strain limiting mechanism,reflected as a non-linear elastic constitutive,to prevent large deformations from threatening soft tissue integrity.Compared with linear elastic substrates,the wrinkle of films on non-linear elastic substrates has received less attention.In this article,a unique wrinkle evolution of the film-substrate system with a J-shaped non-linear stress-strain relation is reported.The result shows that a concave hexagonal array pattern is formed with the shrinkage strain of the film-substrate systems developing.As the interconnection of hexagonal arrays,a unit cell ridge network appears with properties such as chirality and helix.The subparagraph maze pattern formed with high compression is mainly composed of special single-cell ridge networks such as spiral single cores,chiral double cores,and combined multi-cores.This evolutionary model is highly consistent with the results of experiments,and it also predicts wrinkle morphology that has not yet been reported.These findings can serve as a novel explanation for the surface wrinkle of biological soft tissue,as well as provide references for the preparation of artificial biomaterials and programmable soft matter.展开更多
Phosphor-in-glass(PiG)has been prepared into various types of phosphor films owing to its simplicity process,exceptional color purity,and convenient color adjustability.Nevertheless,existing reflective PiGs films have...Phosphor-in-glass(PiG)has been prepared into various types of phosphor films owing to its simplicity process,exceptional color purity,and convenient color adjustability.Nevertheless,existing reflective PiGs films have encountered limitations in terms of stability and feasibility as reliable color converters,mainly attributed to issues related to thermal deposition and insufficient optical efficiency.Herein,we propose to use AlN substrate with superior thermal conductivity to coat the TiO_(2) layer to obtain TiO_(2)-AlN(TA),which enhances the reflectivity of blue light to facilitate the light conversion process.By incorporating highly thermally stable LuAG:Ce-PiGs on a TA substrate,the LuAG:Ce-PiTA converter exhibits a luminous flux of 1102 lm@6.4 W,and maintains a relative intensity of 94.6%at 473 K benefiting from the high thermal conductivity of 34.1 W/(m·K).The addition of CASN_(3):Eu to the color converter 50 L&10C-PiTA enables an impressive CRI of 90.7.Relative lumine scence intensities of LuAG:Ce-PiTA and 50 L&10C-PiTA only decrease by 5.35%and 3.28%,respectively,in the 24 h illumination aging decay test of the reflective laser module.The results confirm the suitability of the optimally designed TA substrate for LuAG:Ce color converter applications in high-power reflective laser illumination.展开更多
Conversion of solar energy into H_(2) by photoelectrochemical(PEC)water splitting is recognized as an ideal way to address the growing energy crisis and environmental issues.In a typical PEC cell,the construction of p...Conversion of solar energy into H_(2) by photoelectrochemical(PEC)water splitting is recognized as an ideal way to address the growing energy crisis and environmental issues.In a typical PEC cell,the construction of photoanodes is crucial to guarantee the high efficiency and stability of PEC reactions,which fundamentally rely on rationally designed semiconductors(as the active materials)and substrates(as the current collectors).In this review work,we start with a brief introduction of the roles of substrates in the PEC process.Then,we provide a systematic overview of representative strategies for the controlled fabrication of photoanodes on rationally designed substrates,including conductive glass,metal,sapphire,silicon,silicon carbide,and flexible substrates.Finally,some prospects concerning the challenges and research directions in this area are proposed.展开更多
Surface-enhanced Raman Spectroscopy(SERS)is a nondestructive technique for rapid detection of analytes even at the single-molecule level.However,highly sensitive and reliable SERS substrates are mostly fabricated with...Surface-enhanced Raman Spectroscopy(SERS)is a nondestructive technique for rapid detection of analytes even at the single-molecule level.However,highly sensitive and reliable SERS substrates are mostly fabricated with complex nanofabrication techniques,greatly restricting their practical applications.A convenient electrochemical method for transforming the surface of commercial gold wires/foils into silver-alloyed nanostructures is demonstrated in this report.Au substrates are treated with repetitive anodic and cathodic bias in an electrolyte of thiourea,in a one-pot one-step manner.X-rays absorption fine structure(XAFS)spectroscopy confirms that the AuAg alloy is induced at the surface.The unique AuAg alloyed surface nanostructures are particularly advantageous when served as SERS substrates,enabling a remarkably sensitive detection of Rhodamine B(a detection limit of 10^(-14)M,and uniform strong response throughout the substrates at 10^(-12)M).展开更多
The unexpected scaling phenomena have resulted in significant damages to the oil and gas industries,leading to issues such as heat exchanger failures and pipeline clogging.It is of practical and fundamental importance...The unexpected scaling phenomena have resulted in significant damages to the oil and gas industries,leading to issues such as heat exchanger failures and pipeline clogging.It is of practical and fundamental importance to understand the scaling mechanisms and develop efficient anti-scaling strategies.However,the underlying surface interaction mechanisms of scalants(e.g.,calcite)with various substrates are still not fully understood.In this work,the colloidal probe atomic force microscopy(AFM)technique has been applied to directly quantify the surface forces between calcite particles and different metallic substrates,including carbon steel(CR1018),low alloy steel(4140),stainless steel(SS304)and tungsten carbide,under different water chemistries(i.e.,salinity and pH).Measured force profiles revealed that the attractive van der Waals(VDW)interaction contributed to the attachment of the calcium carbonate particles on substrate surfaces,while the repulsive electric double layer(EDL)interactions could inhibit the attachment behaviors.High salinity and acidic p H conditions of aqueous solutions could weaken the EDL repulsion and promote the attachment behavior.The adhesion of calcite particles with CR1018 and4140 substrates was much stronger than that with SS304 and tungsten carbide substrates.The bulk scaling tests in aqueous solutions from an industrial oil production process showed that much more severe scaling behaviors of calcite was detected on CR1018 and 4140 than those on SS304 and tungsten carbide,which agreed with surface force measurement results.Besides,high salinity and acidic p H can significantly enhance the scaling phenomena.This work provides fundamental insights into the scaling mechanisms of calcite at the nanoscale with practical implications for the selection of suitable antiscaling materials in petroleum industries.展开更多
Novel substrates consisted of different fresh agro-industrial residues,their corresponding and commercial spent mushroom substrates(i.e.SMS deriving from laboratory-scale experiments and SMS deriving from industrial-s...Novel substrates consisted of different fresh agro-industrial residues,their corresponding and commercial spent mushroom substrates(i.e.SMS deriving from laboratory-scale experiments and SMS deriving from industrial-scale experiments by Green Zin S.A.-SMS GZ)and Pleurotus waste(PW;stipes/mishappen mushrooms)were used in blends for a new cultivation cycle of Pleurotus ostreatus and P.eryngii mushrooms in bags.Their impact on the biochemical properties(intra-cellular polysaccharides-IPSs,protein,lipid,total phenolic compounds-TPCs,individual carbohydrates composition of the IPSs)in the first-and second-flush whole mushrooms,pilei and stipes,as well as the fatty acids composition,the antioxidant activity(in the first-flush mushroom parts)and glucan content of stipes were examined.Both species produced satisfactory IPSs quantities in all substrates(28.69-46.38%,w/w)and significant protein amounts(18.37-26.80%,w/w).The further SMS addition(80%,w/w instead of 40%,w/w)in the cultivation substrates affected positively the mushroom IPSs values,whereas the highest protein content was detected in mushroom’s parts cultivated on substrates consisted of fresh agro-industrial residues.Mushroom’s lipid content was affected differently by the various substrate combinations,with SMS presence resulting in mushrooms with a lower fat content than those produced in substrates with PW addition.Fresh substrates with PW and those with coffee residue were the most favorable for TPCs production.Regarding production flushes,the nutritional value of mushrooms was comparable between them,only a slight increase in TPCs of second-flush carposomes was detected.Glucose was the predominant monosaccharide of the produced IPSs,combined with a significant production of total and β-glucans.SMSs and PW addition had a positive impact on antioxidant activity,too.A higher quantity of lipids,TPCs and significant antioxidant activity were detected in all Pleurotus pilei than stipes,whereas the latter were richer in IPSs.Both pilei and stipes had a significant protein amount.Hence,the data obtained by this study support the positive effect of different types of SMS and mushroom waste on P.ostreatus and P.eryngii nutritional value.展开更多
Mechanical-guided assembly of three-dimensional(3D)mesostructures from pre-defined 2D precursors based on the deterministically controlled buckling has attracted increasing attention in both fundamental and applied re...Mechanical-guided assembly of three-dimensional(3D)mesostructures from pre-defined 2D precursors based on the deterministically controlled buckling has attracted increasing attention in both fundamental and applied research areas,owing to the compelling advantages in developing flexible electronic devices with complex 3D geometries and novel functions.Recently,a buckling-guided strategy was reported to enable assembly of complex 3D mesostructures and electronic devices on cylindrical and cylinder-like substrates,which can be integrated with vascular systems for monitoring of flow rate and other physical signals.A clear understanding of nonlinear buckling deformations of elastic beams assembled on cylindrical substrates is thereby essential for the relevant structural design.In this work,we present a systematic study on the nonlinear deformations of buckled ribbon-type structures on cylindrical substrates.Two representative classes of ribbon-type structures are considered,including arc structures and serpentine structures.Starting with the finite-deformation beam theory,a theoretical model is established to investigate deformed configurations resulted from the controlled buckling,including ribbons assembled on both outer and inner surfaces of the substrate.The structure-substrate contact and self-contact are taken into account in the analyses,which could lead to distinct deformed configurations.Both experimental studies and finite element analyses(FEA)were carried out to validate the developed theoretical model.A demonstrative device design based on the 3D ribbon network outside the cylindrical substrate suggests potential applications in energy harvesting across a broad range of frequency.The theoretical model presented herein could offer insights for the practical design of 3D electronic devices that can be conformally integrated with curvy biological surfaces.展开更多
The emergence of Li–Mg hybrid batteries has been receiving attention,owing to their enhanced electrochemical kinetics and reduced overpotential.Nevertheless,the persistent challenge of uneven Mg electrodeposition rem...The emergence of Li–Mg hybrid batteries has been receiving attention,owing to their enhanced electrochemical kinetics and reduced overpotential.Nevertheless,the persistent challenge of uneven Mg electrodeposition remains a significant impediment to their practical integration.Herein,we developed an ingenious approach that centered around epitaxial electrocrystallization and meticulously controlled growth of magnesium crystals on a specialized MgMOF substrate.The chosen MgMOF substrate demonstrated a robust affinity for magnesium and showed minimal lattice misfit with Mg,establishing the crucial prerequisites for successful heteroepitaxial electrocrystallization.Moreover,the incorporation of periodic electric fields and successive nanochannels within the MgMOF structure created a spatially confined environment that considerably promoted uniform magnesium nucleation at the molecular scale.Taking inspiration from the“blockchain”concept prevalent in the realm of big data,we seamlessly integrated a conductive polypyrrole framework,acting as a connecting“chain,”to interlink the“blocks”comprising the MgMOF cavities.This innovative design significantly amplified charge‐transfer efficiency,thereby increasing overall electrochemical kinetics.The resulting architecture(MgMOF@PPy@CC)served as an exceptional host for heteroepitaxial Mg electrodeposition,showcasing remarkable electrostripping/plating kinetics and excellent cycling performance.Surprisingly,a symmetrical cell incorporating the MgMOF@PPy@CC electrode demonstrated impressive stability even under ultrahigh current density conditions(10mAcm^(–2)),maintaining operation for an extended 1200 h,surpassing previously reported benchmarks.Significantly,on coupling the MgMOF@PPy@CC anode with a Mo_(6)S_(8) cathode,the assembled battery showed an extended lifespan of 10,000 cycles at 70 C,with an outstanding capacity retention of 96.23%.This study provides a fresh perspective on the rational design of epitaxial electrocrystallization driven by metal–organic framework(MOF)substrates,paving the way toward the advancement of cuttingedge batteries.展开更多
Near-field radiative heat transfer(NFRHT)has the potential to exceed the blackbody limit by several orders of magnitude,offering significant opportunities for energy harvesting.In this study,we have examined the NFRHT...Near-field radiative heat transfer(NFRHT)has the potential to exceed the blackbody limit by several orders of magnitude,offering significant opportunities for energy harvesting.In this study,we have examined the NFRHT between two borophene sheets through the calculation of heat transfer coefficient(HTC).Due to the tunneling of evanescent waves,borophene sheet allows for enhanced heat flux and adjustable NFRHT by varying its electron density and electron relaxation time.Additionally,the near field coupling is further examined when the borophene is deposited on dielectric or lossy substrates.The maximum HTC is closely related to the real part of the dielectric substrate.As a case study,the HTCs on the lossy substrate of MoO_(3),ZnSe,and SiC are calculated for comparisons.Our results indicate that MoO_(3)is the optimal substrate to get the enhanced energy transfer coefficient.It results in a remarkable value of 1737 times higher than the blackbody limit owing to the enhanced photon tunneling probability.Thus,our study reveals the effect of substrate on the HTC between borophene sheets and provides a theoretical guidance for the design of near-field thermal radiation devices.展开更多
Direct synthesis of layer-tunable and transfer-free graphene on technologically important substrates is highly valued for various electronics and device applications.State of the art in the field is currently a two-st...Direct synthesis of layer-tunable and transfer-free graphene on technologically important substrates is highly valued for various electronics and device applications.State of the art in the field is currently a two-step process:a high-quality graphene layer synthesis on metal substrate through chemical vapor deposition(CVD)followed by delicate layer transfer onto device-relevant substrates.Here,we report a novel synthesis approach combining ion implantation for a precise graphene layer control and dual-metal smart Janus substrate for a diffusion-limiting graphene formation to directly synthesize large area,high quality,and layer-tunable graphene films on arbitrary substrates without the post-synthesis layer transfer process.Carbon(C)ion implantation was performed on Cu-Ni film deposited on a variety of device-relevant substrates.A well-controlled number of layers of graphene,primarily monolayer and bilayer,is precisely controlled by the equivalent fluence of the implanted C-atoms(1 monolayer~4×10^(15)C-atoms/cm^(2)).Upon thermal annealing to promote Cu-Ni alloying,the pre-implanted C-atoms in the Ni layer are pushed toward the Ni/substrate interface by the top Cu layer due to the poor C-solubility in Cu.As a result,the expelled C-atoms precipitate into a graphene structure at the interface facilitated by the Cu-like alloy catalysis.After removing the alloyed Cu-like surface layer,the layer-tunable graphene on the desired substrate is directly realized.The layer-selectivity,high quality,and uniformity of the graphene films are not only confirmed with detailed characterizations using a suite of surface analysis techniques but more importantly are successfully demonstrated by the excellent properties and performance of several devices directly fabricated from these graphene films.Molecular dynamics(MD)simulations using the reactive force field(ReaxFF)were performed to elucidate the graphene formation mechanisms in this novel synthesis approach.With the wide use of ion implantation technology in the microelectronics industry,this novel graphene synthesis approach with precise layer-tunability and transfer-free processing has the promise to advance efficient graphene-device manufacturing and expedite their versatile applications in many fields.展开更多
The effect of nano-carbon black content(O,8 and 12 wt.%)on the wettability of molten steel on Al_(2)O_(3)-C substrates was investigated by the sessile drop wetting method at 1500℃ under argon atmosphere.At the beginn...The effect of nano-carbon black content(O,8 and 12 wt.%)on the wettability of molten steel on Al_(2)O_(3)-C substrates was investigated by the sessile drop wetting method at 1500℃ under argon atmosphere.At the beginning of the wetting experiment,the contact angle decreased with the increase in nano-carbon black content.As the wetting experiment progressed,FeAl_(2)0_(4) layer and sheet Al_(2)O_(3) layer were found at the interface between the molten steel and the Al_(2)O_(3)-C substrates with O and 8 wt.% nano-carbon black content,and the contact angle deceased with time.When the content of nano-carbon black was 12 wt.%,a large number of nano-Al_(2)O_(3) whiskers were observed,which made the contact angle between the molten steel and Al_(2)O_(3)-C substrate become large.Based on the scanning electron microscope and energy dispersive spectrometry results,the formation mechanism of FeAl2O4 layer and Al_(2)O_(3) layer and the interfacial reaction mechanism were proposed.展开更多
This work shows that despite a lattice mismatch of almost 20%, CdMnTe/CdTe/CdMnTe heterostructures grown directly on Si(111) have surprisingly good optical emission properties. The investigated structures were grown b...This work shows that despite a lattice mismatch of almost 20%, CdMnTe/CdTe/CdMnTe heterostructures grown directly on Si(111) have surprisingly good optical emission properties. The investigated structures were grown by molecular beam epitaxy and characterized by scanning transmission electron microscopy, macro-and micro-photoluminescence. Low temperature macro-photoluminescence experiments indicate three emission bands which depend on the CdTe layer thickness and have different confinement characteristics. Temperature measurements reveal that the lower energy emission band (at 1.48 eV)is associated to defects and bound exciton states, while the main emission at 1.61 eV has a weak 2D character and the higher energy one at 1.71 eV has a well-defined (zero-dimensional, 0D) 0D nature. Micro-photoluminescence measurements show the existence of sharp and strongly circularly polarized (up to 40%) emission lines which can be related to the presence of Mn in the heterostructure. This result opens the possibility of producing photon sources with the typical spin control of the diluted magnetic semiconductors using the low-cost silicon technology.展开更多
High-performance type-Ⅱsuperlattices ofⅢ-Ⅴsemiconductor materials play an important role in the development and application of infrared optoelectronic devices.Improving the quality of epitaxial materials and clarif...High-performance type-Ⅱsuperlattices ofⅢ-Ⅴsemiconductor materials play an important role in the development and application of infrared optoelectronic devices.Improving the quality of epitaxial materials and clarifying the luminescent mechanism are of great significance for practic al applic ations.In this work,strain-balanced and high-quality In As/In_(x)Ga_(1-x)As_(y)Sb_(1-y)superlattices without lattice mismatch were achieved on InAs and GaSb substrates successfully.Superlattices grown on In As substrate could exhibit higher crystal quality and surface flatness based on high-resolution X-ray diffraction(HRXRD)and atomic force microscopy(AFM)measurements'results.Moreover,the strain distribution phenomenon from geometric phase analysis indicates that fluctuations of alloy compositions in superlattices on GaSb substrate are more obvious.In addition,the optical properties of superlattices grown on different substrates are discussed systematically.Because of the difference in fluctuations of element composition and interface roughness of superlattices on different substrates,the superlattices grown on In As substrate would have higher integral intensity and narrower full-width at half maximum of long-wave infrared emission.Finally,the thermal quenching of emission intensity indicates that the superlattices grown on the In As substrate have better recombination ability,which is beneficial for increasing the operating temperature of infrared optoelectronic devices based on this type of superlattices.展开更多
[Objectives]The paper was to explore the impact of different cultivation substrates on the growth of Cymbidium goeringii.[Methods]The impact of 13 distinct cultivation substrates on the growth of C.goeringii was exami...[Objectives]The paper was to explore the impact of different cultivation substrates on the growth of Cymbidium goeringii.[Methods]The impact of 13 distinct cultivation substrates on the growth of C.goeringii was examined using C.goeringii as the test material.[Results]The combination of burning red clay particles(15%),No.4 pine bark(15%),No.3 pine bark(60%),and perlite(10%),as well as the mixture of burning red clay particles(20%),No.4 pine bark(15%),No.3 pine bark(55%),and perlite(10%),yielded superior results.These formulations resulted in an increased number of new roots in C.goeringii,a reduction in the incidence of decayed roots,and enhancements in the number of tillers,new leaves,and flowers.[Conclusions]The selection of substrates may serve as a valuable reference for the cultivation of C.goeringii.展开更多
The characteristics of hot filament chemical vapor deposition（HFCVD） diamond films are significantly influenced by the deposition parameters, such as the substrate temperature, total pressure and carbon concentratio...The characteristics of hot filament chemical vapor deposition（HFCVD） diamond films are significantly influenced by the deposition parameters, such as the substrate temperature, total pressure and carbon concentration. Orthogonal experiments were introduced to study the comprehensive effects of such three parameters on diamond films deposited on WC-Co substrates. Field emission scanning electron microscopy, atomic force microscopy and Raman spectrum were employed to analyze the morphology, growth rate and composition of as-deposited diamond films. The morphology varies from pyramidal to cluster features with temperature decreasing. It is found that the low total pressure is suitable for nano-crystalline diamond films growth. Moreover, the substrate temperature and total pressure have combined influence on the growth rate of the diamond films.展开更多
文摘This research aims to explore the decoration of TiO_(2)substrates with silver nanoparticles as a means of enhancing the photocatalytic oxidation of organic compounds.The results show that decorated TiO_(2)substrates exhibit significantly higher photocatalytic activity in sunlight than undecorated substrates.Morphological analysis is performed,followed by optical and structural characterizations.Scanning electron microscopy analysis of the TiO_(2)reveals many nanotubular structures with particle sizes of∼134.4,148.8,and 132.7 nm at random locations.TiO_(2)is also found to have an absorbance range of 397.6 nm,from which it is known that the photocatalyst reacts in the presence of an ultraviolet source.From the Miller indices of the x-ray diffraction peaks,the preferred crystal orientation is found to be associated with a face-centered cubic structure with a crystallite size of 3.76 nm.Using these promising results,photocatalytic analysis is performed,revealing good degradation characteristics.This investigation reveals that TiO_(2)substrates coated with Ag nanoparticles possess significant potential for application in the photocatalytic oxidation of methylene blue dye,which is a crucial step toward establishing a cleaner environment.
基金supported by the National Natural Science Foundation of China(Grant Nos.12374459,61974138,and 92065106)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302400)+1 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB0460000)the support from the Youth Innovation Promotion Association,Chinese Academy of Sciences(Grant Nos.2017156 and Y2021043)。
文摘Anti-phase domain defects easily form in the in-plane GaAs nanowires(NWs)grown on CMOS-compatiblegroup IV substrates,which makes it difficult to obtain GaAs NWs with a designed length and also leads to asignificant limitation in the growth of high-quality in-plane GaAs NW networks on such substrates.Here,wereport on the selective area growth of anti-phase domain-free in-plane GaAs NWs and NW networks on Ge(111)substrates.Detailed structural studies confirm that the GaAs NW grown using a large pattern period and GaAsNW networks grown by adding the Sb are both high-quality pure zinc-blende single crystals free of stackingfaults,twin defects,and anti-phase domain defects.Room-temperature photoluminescence measurements show asubstantial improvement in crystal quality and good consistency and uniformity of the GaAs NW networks.Ourwork provides useful insights into the controlled growth of high-quality anti-phase domain-defects-free in-planeIII-V NWs and NW networks.
文摘Constructed Wetlands (CWs) are currently one of the most promising techniques for wastewater treatment, having demonstrated their effectiveness. However, the choice of substrate particle size is critical to the smooth operation of the process, as hydrodynamic constraints require a coarse particle size, whereas wastewater treatment recommends a fine particle size. This study investigates the suitability of laterite and shale as substrates of different sizes (1 - 3, 3 - 5 and 5 - 8 mm) in CWs for domestic wastewater treatment. The study was carried out in an experimental pilot plant consisting of 12 parallelepiped beds (C × C = 0.4 × 0.4 m2;H = 0.6 m) filled from bottom to top with 0.1 m of gravel and 0.4 m of shale or laterite of different grain sizes with two replications. During the six months of operation, plant biomass and stem diameter of Pennisetum purpureum used as vegetation in the CWs were determined. Raw and treated water were also sampled and analyzed for pollutants, including chemical oxygen demand (COD), biochemical oxygen demand (BOD5), total Kjedahl nitrogen (TKN), total phosphorus (TP), and total suspended solids (TSS), using International Organization for Standardization (ISO) analytical methods. P. purpureum developed much better in the CW beds lined with shale;plant biomass ranged from 13.8 to 14.7 kg/m2 and from 11.2 to 12.5 kg/m2 in the beds lined with shale and laterite, respectively, as did stump diameter, which ranged from 15.5 to 16.1 cm and from 11.10 to 12.7 cm, respectively. However, the highest values for biomass and stump diameter for each material were obtained in the beds lined with 1 - 3 mm geomaterials. Pollutant removal efficiencies were highest in the CWs lined with laterite and shale of 1 - 3 mm grain size (76.9% - 83% COD, 78% - 84.7% BOD5, 55.5% - 72.2% TKN, 58.4% - 72.4% TP, 78.1% - 80.2% TSS), with the highest values recorded in the shale-lined beds. However, the 3 - 5 mm grain size of both materials provided quality filtrates (140 - 174 mg/L COD, 78.5 - 94.8 mg/L BOD5, 4.6 - 5.7 mg/L TP) in line with local wastewater discharge levels. This size of geomaterials appears to be suitable for optimization purposes, although further work with these materials, such as increasing the depth of the wetland, is required to improve the level of NTK and TSS discharge.
基金Funded by the International Science&Technology Cooperation Program of Hubei Province of China(No.2022EHB024)the National Key Research and Development Plan(Nos.2018YFE0103600 and 2021YFB3703100)+1 种基金the National Natural Science Foundation of China(Nos.51872212,51972244,52002075,and 52102066)the 111 Project(No.B13035)。
文摘Laser etching and laser chemical vapor deposition(LCVD)techniques were proposed for the rapid preparation of high-purity,strongly bonded SiC porous micro-nano-coatings on quartz substrates.The laser serves as an external driving force for the vertical growth of SiC whiskers,facilitating the formation of a porous nanostructure that resembles coral models found in the macroscopic biological world.The porous nanostructures are beneficial for reducing thermal expansion mismatch and relieving residual stress.It is capable of eliminating the cracks on the surface of SiC coatings as well as enhancing the bonding of SiC coatings with quartz substrates to avoid coating detachment.
文摘The influence of the electronic and steric properties of bromoaromatic substrates on direct arylation polymerization for synthesizing high-molecular-weight conjugated polymers was investigated through a combination of experiments and calculations.Bromo-aromatic substrates with electron-withdrawing fluoro substituents exhibited higher yields and degrees of polymerization under PPh3-assisted conditions compared to those with electron-donating or bulky methyl substituents.Additionally,excessive steric hindrance at ortho-sites or overly electrondeficient dibromoaromatic substrates leads to reaction inactivation.Calculations indicated that electron-withdrawing substituents enhanced the electrophilicity of arylpalladium-PPh3intermediates,facilitating the activation of electron-rich arylative substrates and promoting polymer growth.Furthermore,steric hindrance from the substituents can influence the preferred reaction pathway,thereby increasing the real reaction barriers.Both experimental and computational results suggest that bromoaromatic substrates with optimized electron-deficient characteristics significantly improve monomer conversion and polymerization efficiency with n-hexylmethylether-substituted EDOT.These findings clarify how the electronic and steric properties of bromo-aromatic substrates affect EDOT derivative activation and are expected to aid in optimizing the polymerization conditions for the preparation of high-molecular-weight conjugated polymers.
基金This work was supported by the Youth Project of Hunan Provincial Department of Education(Grant No.22B0334)the Bridge and Tunnel Engineering Innovation Project of Changsha University of Science&Technology(Grant No.11ZDXK11)and the Practical Innovation and Entrepreneurship Capacity Improvement Plan of Changsha University of Science and Technology(Grant No.CLSJCX23029).
文摘Organisms have evolved a strain limiting mechanism,reflected as a non-linear elastic constitutive,to prevent large deformations from threatening soft tissue integrity.Compared with linear elastic substrates,the wrinkle of films on non-linear elastic substrates has received less attention.In this article,a unique wrinkle evolution of the film-substrate system with a J-shaped non-linear stress-strain relation is reported.The result shows that a concave hexagonal array pattern is formed with the shrinkage strain of the film-substrate systems developing.As the interconnection of hexagonal arrays,a unit cell ridge network appears with properties such as chirality and helix.The subparagraph maze pattern formed with high compression is mainly composed of special single-cell ridge networks such as spiral single cores,chiral double cores,and combined multi-cores.This evolutionary model is highly consistent with the results of experiments,and it also predicts wrinkle morphology that has not yet been reported.These findings can serve as a novel explanation for the surface wrinkle of biological soft tissue,as well as provide references for the preparation of artificial biomaterials and programmable soft matter.
文摘Phosphor-in-glass(PiG)has been prepared into various types of phosphor films owing to its simplicity process,exceptional color purity,and convenient color adjustability.Nevertheless,existing reflective PiGs films have encountered limitations in terms of stability and feasibility as reliable color converters,mainly attributed to issues related to thermal deposition and insufficient optical efficiency.Herein,we propose to use AlN substrate with superior thermal conductivity to coat the TiO_(2) layer to obtain TiO_(2)-AlN(TA),which enhances the reflectivity of blue light to facilitate the light conversion process.By incorporating highly thermally stable LuAG:Ce-PiGs on a TA substrate,the LuAG:Ce-PiTA converter exhibits a luminous flux of 1102 lm@6.4 W,and maintains a relative intensity of 94.6%at 473 K benefiting from the high thermal conductivity of 34.1 W/(m·K).The addition of CASN_(3):Eu to the color converter 50 L&10C-PiTA enables an impressive CRI of 90.7.Relative lumine scence intensities of LuAG:Ce-PiTA and 50 L&10C-PiTA only decrease by 5.35%and 3.28%,respectively,in the 24 h illumination aging decay test of the reflective laser module.The results confirm the suitability of the optimally designed TA substrate for LuAG:Ce color converter applications in high-power reflective laser illumination.
基金Natural Science Foundation of Zhejiang Province,Grant/Award Number:LY23E020002National Natural Science Foundation of China,Grant/Award Number:52272085 and 51972178+1 种基金Natural Science Foundation of Ningbo,Grant/Award Number:2021J145China Postdoctoral Science Foundation,Grant/Award Number:2020M681966。
文摘Conversion of solar energy into H_(2) by photoelectrochemical(PEC)water splitting is recognized as an ideal way to address the growing energy crisis and environmental issues.In a typical PEC cell,the construction of photoanodes is crucial to guarantee the high efficiency and stability of PEC reactions,which fundamentally rely on rationally designed semiconductors(as the active materials)and substrates(as the current collectors).In this review work,we start with a brief introduction of the roles of substrates in the PEC process.Then,we provide a systematic overview of representative strategies for the controlled fabrication of photoanodes on rationally designed substrates,including conductive glass,metal,sapphire,silicon,silicon carbide,and flexible substrates.Finally,some prospects concerning the challenges and research directions in this area are proposed.
基金supported by Shenzhen-Hong Kong Science and Technology Innovation Cooperation Zone Shenzhen Park (Project HZQBKCZYB-2020030)National Key R&D Program of China (Project 2017YFA0204403)+2 种基金the National Natural Science Foundation of China (Project 51590892)the Major Program of Changsha Science and Technology (Project kh2003023)the Innovation and Technology Commission of HKSAR through Hong Kong Branch of National Precious Metals Material Engineering Research Centre,and the City University of Hong Kong (Project 9667207)。
文摘Surface-enhanced Raman Spectroscopy(SERS)is a nondestructive technique for rapid detection of analytes even at the single-molecule level.However,highly sensitive and reliable SERS substrates are mostly fabricated with complex nanofabrication techniques,greatly restricting their practical applications.A convenient electrochemical method for transforming the surface of commercial gold wires/foils into silver-alloyed nanostructures is demonstrated in this report.Au substrates are treated with repetitive anodic and cathodic bias in an electrolyte of thiourea,in a one-pot one-step manner.X-rays absorption fine structure(XAFS)spectroscopy confirms that the AuAg alloy is induced at the surface.The unique AuAg alloyed surface nanostructures are particularly advantageous when served as SERS substrates,enabling a remarkably sensitive detection of Rhodamine B(a detection limit of 10^(-14)M,and uniform strong response throughout the substrates at 10^(-12)M).
基金support from Science Foundation of China University of Petroleum,Beijing (No.2462023QNXZ018)the Natural Sciences and Engineering Research Council of Canada (NSERC)+2 种基金Canada Foundation for Innovation (CFI)the Research Capacity Program (RCP)of Albertathe Canada Research Chairs Program。
文摘The unexpected scaling phenomena have resulted in significant damages to the oil and gas industries,leading to issues such as heat exchanger failures and pipeline clogging.It is of practical and fundamental importance to understand the scaling mechanisms and develop efficient anti-scaling strategies.However,the underlying surface interaction mechanisms of scalants(e.g.,calcite)with various substrates are still not fully understood.In this work,the colloidal probe atomic force microscopy(AFM)technique has been applied to directly quantify the surface forces between calcite particles and different metallic substrates,including carbon steel(CR1018),low alloy steel(4140),stainless steel(SS304)and tungsten carbide,under different water chemistries(i.e.,salinity and pH).Measured force profiles revealed that the attractive van der Waals(VDW)interaction contributed to the attachment of the calcium carbonate particles on substrate surfaces,while the repulsive electric double layer(EDL)interactions could inhibit the attachment behaviors.High salinity and acidic p H conditions of aqueous solutions could weaken the EDL repulsion and promote the attachment behavior.The adhesion of calcite particles with CR1018 and4140 substrates was much stronger than that with SS304 and tungsten carbide substrates.The bulk scaling tests in aqueous solutions from an industrial oil production process showed that much more severe scaling behaviors of calcite was detected on CR1018 and 4140 than those on SS304 and tungsten carbide,which agreed with surface force measurement results.Besides,high salinity and acidic p H can significantly enhance the scaling phenomena.This work provides fundamental insights into the scaling mechanisms of calcite at the nanoscale with practical implications for the selection of suitable antiscaling materials in petroleum industries.
文摘Novel substrates consisted of different fresh agro-industrial residues,their corresponding and commercial spent mushroom substrates(i.e.SMS deriving from laboratory-scale experiments and SMS deriving from industrial-scale experiments by Green Zin S.A.-SMS GZ)and Pleurotus waste(PW;stipes/mishappen mushrooms)were used in blends for a new cultivation cycle of Pleurotus ostreatus and P.eryngii mushrooms in bags.Their impact on the biochemical properties(intra-cellular polysaccharides-IPSs,protein,lipid,total phenolic compounds-TPCs,individual carbohydrates composition of the IPSs)in the first-and second-flush whole mushrooms,pilei and stipes,as well as the fatty acids composition,the antioxidant activity(in the first-flush mushroom parts)and glucan content of stipes were examined.Both species produced satisfactory IPSs quantities in all substrates(28.69-46.38%,w/w)and significant protein amounts(18.37-26.80%,w/w).The further SMS addition(80%,w/w instead of 40%,w/w)in the cultivation substrates affected positively the mushroom IPSs values,whereas the highest protein content was detected in mushroom’s parts cultivated on substrates consisted of fresh agro-industrial residues.Mushroom’s lipid content was affected differently by the various substrate combinations,with SMS presence resulting in mushrooms with a lower fat content than those produced in substrates with PW addition.Fresh substrates with PW and those with coffee residue were the most favorable for TPCs production.Regarding production flushes,the nutritional value of mushrooms was comparable between them,only a slight increase in TPCs of second-flush carposomes was detected.Glucose was the predominant monosaccharide of the produced IPSs,combined with a significant production of total and β-glucans.SMSs and PW addition had a positive impact on antioxidant activity,too.A higher quantity of lipids,TPCs and significant antioxidant activity were detected in all Pleurotus pilei than stipes,whereas the latter were richer in IPSs.Both pilei and stipes had a significant protein amount.Hence,the data obtained by this study support the positive effect of different types of SMS and mushroom waste on P.ostreatus and P.eryngii nutritional value.
基金supported by the National Natural Science Foundation of China(Grant Nos.12225206 and 11921002)the Tsinghua National Laboratory for Information Science and Technology,and a grant from the Institute for Guo Qiang,Tsinghua University(Grant No.2021GQG1009).
文摘Mechanical-guided assembly of three-dimensional(3D)mesostructures from pre-defined 2D precursors based on the deterministically controlled buckling has attracted increasing attention in both fundamental and applied research areas,owing to the compelling advantages in developing flexible electronic devices with complex 3D geometries and novel functions.Recently,a buckling-guided strategy was reported to enable assembly of complex 3D mesostructures and electronic devices on cylindrical and cylinder-like substrates,which can be integrated with vascular systems for monitoring of flow rate and other physical signals.A clear understanding of nonlinear buckling deformations of elastic beams assembled on cylindrical substrates is thereby essential for the relevant structural design.In this work,we present a systematic study on the nonlinear deformations of buckled ribbon-type structures on cylindrical substrates.Two representative classes of ribbon-type structures are considered,including arc structures and serpentine structures.Starting with the finite-deformation beam theory,a theoretical model is established to investigate deformed configurations resulted from the controlled buckling,including ribbons assembled on both outer and inner surfaces of the substrate.The structure-substrate contact and self-contact are taken into account in the analyses,which could lead to distinct deformed configurations.Both experimental studies and finite element analyses(FEA)were carried out to validate the developed theoretical model.A demonstrative device design based on the 3D ribbon network outside the cylindrical substrate suggests potential applications in energy harvesting across a broad range of frequency.The theoretical model presented herein could offer insights for the practical design of 3D electronic devices that can be conformally integrated with curvy biological surfaces.
基金National Natural Science Foundation of China,Grant/Award Number:31770608Postgraduate Research&Practice Innovation Program of Jiangsu Province,Grant/Award Number:KYCX22_1081Jiangsu Specially‐appointed Professorship Program,Grant/Award Number:Sujiaoshi[2016]20。
文摘The emergence of Li–Mg hybrid batteries has been receiving attention,owing to their enhanced electrochemical kinetics and reduced overpotential.Nevertheless,the persistent challenge of uneven Mg electrodeposition remains a significant impediment to their practical integration.Herein,we developed an ingenious approach that centered around epitaxial electrocrystallization and meticulously controlled growth of magnesium crystals on a specialized MgMOF substrate.The chosen MgMOF substrate demonstrated a robust affinity for magnesium and showed minimal lattice misfit with Mg,establishing the crucial prerequisites for successful heteroepitaxial electrocrystallization.Moreover,the incorporation of periodic electric fields and successive nanochannels within the MgMOF structure created a spatially confined environment that considerably promoted uniform magnesium nucleation at the molecular scale.Taking inspiration from the“blockchain”concept prevalent in the realm of big data,we seamlessly integrated a conductive polypyrrole framework,acting as a connecting“chain,”to interlink the“blocks”comprising the MgMOF cavities.This innovative design significantly amplified charge‐transfer efficiency,thereby increasing overall electrochemical kinetics.The resulting architecture(MgMOF@PPy@CC)served as an exceptional host for heteroepitaxial Mg electrodeposition,showcasing remarkable electrostripping/plating kinetics and excellent cycling performance.Surprisingly,a symmetrical cell incorporating the MgMOF@PPy@CC electrode demonstrated impressive stability even under ultrahigh current density conditions(10mAcm^(–2)),maintaining operation for an extended 1200 h,surpassing previously reported benchmarks.Significantly,on coupling the MgMOF@PPy@CC anode with a Mo_(6)S_(8) cathode,the assembled battery showed an extended lifespan of 10,000 cycles at 70 C,with an outstanding capacity retention of 96.23%.This study provides a fresh perspective on the rational design of epitaxial electrocrystallization driven by metal–organic framework(MOF)substrates,paving the way toward the advancement of cuttingedge batteries.
基金Project supported by the Natural Science Foundation of Henan Province,China(Grant No.232102231023)。
文摘Near-field radiative heat transfer(NFRHT)has the potential to exceed the blackbody limit by several orders of magnitude,offering significant opportunities for energy harvesting.In this study,we have examined the NFRHT between two borophene sheets through the calculation of heat transfer coefficient(HTC).Due to the tunneling of evanescent waves,borophene sheet allows for enhanced heat flux and adjustable NFRHT by varying its electron density and electron relaxation time.Additionally,the near field coupling is further examined when the borophene is deposited on dielectric or lossy substrates.The maximum HTC is closely related to the real part of the dielectric substrate.As a case study,the HTCs on the lossy substrate of MoO_(3),ZnSe,and SiC are calculated for comparisons.Our results indicate that MoO_(3)is the optimal substrate to get the enhanced energy transfer coefficient.It results in a remarkable value of 1737 times higher than the blackbody limit owing to the enhanced photon tunneling probability.Thus,our study reveals the effect of substrate on the HTC between borophene sheets and provides a theoretical guidance for the design of near-field thermal radiation devices.
基金supported by the National Key R&D Program of China(No.2022YFA1203400)the National Natural Science Foundation of China under Grant(Nos.62174093 and 12075307)+7 种基金the Ningbo Youth Science and Technology Innovation Leading Talent Project under Grant(No.2023QL006)the Open Research Fund of China National Key Laboratory of Materials for Integrated Circuits(No.NKLJC-K2023-01)Guangdong Basic and Applied Basic Research Foundation(No.2022A1515110628)the support by LDRD Seedling ER project at Los Alamos National Laboratory,NM,USA(No.20210867ER)partially supported by Guangdong Provincial Key Laboratory of Computational Science and Material Design(No.2019B030301001)supported by Center for Computational Science and Engineering at Southern University of Science and TechnologyShanghai Rising-Star Program(No.21QA1410900)the support from the Youth Innovation Promotion Association CAS
文摘Direct synthesis of layer-tunable and transfer-free graphene on technologically important substrates is highly valued for various electronics and device applications.State of the art in the field is currently a two-step process:a high-quality graphene layer synthesis on metal substrate through chemical vapor deposition(CVD)followed by delicate layer transfer onto device-relevant substrates.Here,we report a novel synthesis approach combining ion implantation for a precise graphene layer control and dual-metal smart Janus substrate for a diffusion-limiting graphene formation to directly synthesize large area,high quality,and layer-tunable graphene films on arbitrary substrates without the post-synthesis layer transfer process.Carbon(C)ion implantation was performed on Cu-Ni film deposited on a variety of device-relevant substrates.A well-controlled number of layers of graphene,primarily monolayer and bilayer,is precisely controlled by the equivalent fluence of the implanted C-atoms(1 monolayer~4×10^(15)C-atoms/cm^(2)).Upon thermal annealing to promote Cu-Ni alloying,the pre-implanted C-atoms in the Ni layer are pushed toward the Ni/substrate interface by the top Cu layer due to the poor C-solubility in Cu.As a result,the expelled C-atoms precipitate into a graphene structure at the interface facilitated by the Cu-like alloy catalysis.After removing the alloyed Cu-like surface layer,the layer-tunable graphene on the desired substrate is directly realized.The layer-selectivity,high quality,and uniformity of the graphene films are not only confirmed with detailed characterizations using a suite of surface analysis techniques but more importantly are successfully demonstrated by the excellent properties and performance of several devices directly fabricated from these graphene films.Molecular dynamics(MD)simulations using the reactive force field(ReaxFF)were performed to elucidate the graphene formation mechanisms in this novel synthesis approach.With the wide use of ion implantation technology in the microelectronics industry,this novel graphene synthesis approach with precise layer-tunability and transfer-free processing has the promise to advance efficient graphene-device manufacturing and expedite their versatile applications in many fields.
基金This work was funded by the National Natural Science Foundation of China(No.51974214)the Natural Science Funds of Hubei Province for Distinguished Young Scholars(Grant No.2020CFA088).
文摘The effect of nano-carbon black content(O,8 and 12 wt.%)on the wettability of molten steel on Al_(2)O_(3)-C substrates was investigated by the sessile drop wetting method at 1500℃ under argon atmosphere.At the beginning of the wetting experiment,the contact angle decreased with the increase in nano-carbon black content.As the wetting experiment progressed,FeAl_(2)0_(4) layer and sheet Al_(2)O_(3) layer were found at the interface between the molten steel and the Al_(2)O_(3)-C substrates with O and 8 wt.% nano-carbon black content,and the contact angle deceased with time.When the content of nano-carbon black was 12 wt.%,a large number of nano-Al_(2)O_(3) whiskers were observed,which made the contact angle between the molten steel and Al_(2)O_(3)-C substrate become large.Based on the scanning electron microscope and energy dispersive spectrometry results,the formation mechanism of FeAl2O4 layer and Al_(2)O_(3) layer and the interfacial reaction mechanism were proposed.
基金the financial support by the Brazilian funding agencies CAPES, CNPq (306201/2022-4)FAPEMIG (APQ-00371-17, APQ-02500-22, APQ-00388-22, and RED00223-23)FAPESP (2021/06803-4)。
文摘This work shows that despite a lattice mismatch of almost 20%, CdMnTe/CdTe/CdMnTe heterostructures grown directly on Si(111) have surprisingly good optical emission properties. The investigated structures were grown by molecular beam epitaxy and characterized by scanning transmission electron microscopy, macro-and micro-photoluminescence. Low temperature macro-photoluminescence experiments indicate three emission bands which depend on the CdTe layer thickness and have different confinement characteristics. Temperature measurements reveal that the lower energy emission band (at 1.48 eV)is associated to defects and bound exciton states, while the main emission at 1.61 eV has a weak 2D character and the higher energy one at 1.71 eV has a well-defined (zero-dimensional, 0D) 0D nature. Micro-photoluminescence measurements show the existence of sharp and strongly circularly polarized (up to 40%) emission lines which can be related to the presence of Mn in the heterostructure. This result opens the possibility of producing photon sources with the typical spin control of the diluted magnetic semiconductors using the low-cost silicon technology.
基金financially supported by the National Natural Science Foundation of China(Nos.62074018,62174015 and 62275032)the Developing Project of Science and Technology of Jilin Province(No.20210509061RQ)+3 种基金the Natural Science Foundation of Jilin Province(No.20210101473JC)National Key R&D Program of China(No.2021YFB3201901)The Natural Science Foundation of Chongqing China(No.cstc2021jcyjmsxmX1060)supported by R&D project of Collighter Co.,Ltd。
文摘High-performance type-Ⅱsuperlattices ofⅢ-Ⅴsemiconductor materials play an important role in the development and application of infrared optoelectronic devices.Improving the quality of epitaxial materials and clarifying the luminescent mechanism are of great significance for practic al applic ations.In this work,strain-balanced and high-quality In As/In_(x)Ga_(1-x)As_(y)Sb_(1-y)superlattices without lattice mismatch were achieved on InAs and GaSb substrates successfully.Superlattices grown on In As substrate could exhibit higher crystal quality and surface flatness based on high-resolution X-ray diffraction(HRXRD)and atomic force microscopy(AFM)measurements'results.Moreover,the strain distribution phenomenon from geometric phase analysis indicates that fluctuations of alloy compositions in superlattices on GaSb substrate are more obvious.In addition,the optical properties of superlattices grown on different substrates are discussed systematically.Because of the difference in fluctuations of element composition and interface roughness of superlattices on different substrates,the superlattices grown on In As substrate would have higher integral intensity and narrower full-width at half maximum of long-wave infrared emission.Finally,the thermal quenching of emission intensity indicates that the superlattices grown on the In As substrate have better recombination ability,which is beneficial for increasing the operating temperature of infrared optoelectronic devices based on this type of superlattices.
基金Supported by Spark Program of Fujian Province(2021S0055).
文摘[Objectives]The paper was to explore the impact of different cultivation substrates on the growth of Cymbidium goeringii.[Methods]The impact of 13 distinct cultivation substrates on the growth of C.goeringii was examined using C.goeringii as the test material.[Results]The combination of burning red clay particles(15%),No.4 pine bark(15%),No.3 pine bark(60%),and perlite(10%),as well as the mixture of burning red clay particles(20%),No.4 pine bark(15%),No.3 pine bark(55%),and perlite(10%),yielded superior results.These formulations resulted in an increased number of new roots in C.goeringii,a reduction in the incidence of decayed roots,and enhancements in the number of tillers,new leaves,and flowers.[Conclusions]The selection of substrates may serve as a valuable reference for the cultivation of C.goeringii.
基金Project(2012ZX04003-031)supported by the National Science and Technology Major Project,China
文摘The characteristics of hot filament chemical vapor deposition（HFCVD） diamond films are significantly influenced by the deposition parameters, such as the substrate temperature, total pressure and carbon concentration. Orthogonal experiments were introduced to study the comprehensive effects of such three parameters on diamond films deposited on WC-Co substrates. Field emission scanning electron microscopy, atomic force microscopy and Raman spectrum were employed to analyze the morphology, growth rate and composition of as-deposited diamond films. The morphology varies from pyramidal to cluster features with temperature decreasing. It is found that the low total pressure is suitable for nano-crystalline diamond films growth. Moreover, the substrate temperature and total pressure have combined influence on the growth rate of the diamond films.
