Solid-state polymer electrolytes are crucial for advancing solid-state lithium-metal batteries owing to their flexibility,excellent manufacturability,and strong interfacial compatibility.However,their widespread appli...Solid-state polymer electrolytes are crucial for advancing solid-state lithium-metal batteries owing to their flexibility,excellent manufacturability,and strong interfacial compatibility.However,their widespread applications are hindered by low ionic conductivity at room temperature and lithium dendrite growth.Herein,we report a novel solid-state composite membrane electrolyte design that combines the vertically aligned channel structure and copolymer with a radial gradient composition.Within the vertically aligned channels,the composition of poly(vinyl ethylene carbonate-co-poly(ethylene glycol)diacrylate)(P(VEC-PEGDA)varies in a gradient along the radial direction:from the center to the wall of vertically aligned channels,the proportion of vinyl ethylene carbonate(VEC)in the copolymer decreases,while the proportion of poly(ethylene glycol)diacrylate(PEGDA)increases accordingly.It can be functionally divided into a mechanical-reinforcement layer and a fast-ion-conducting layer.The resulting solid-state composite membrane electrolyte achieves a high critical current density of 1.2 mA cm^(-2)and high ionic conductivity of 2.03 mS cm^(-1)at room temperature.Employing this composite membrane electrolyte,a Li//Li symmetric cell exhibits stable cycling for over 1850 h at 0.2 m A cm^(-2)/0.2 m A h cm^(-2),and a Li//LiFePO4(LFP)battery maintains 77.3% capacity retention at 2 C after 300 cycles.Our work provides insight into the rational design of safer and more efficient solidstate batteries through electrolyte structural engineering.展开更多
High-performance lithium metal batteries benefit from the construction of composite polymer electrolytes(CPEs)which are synthesized by incorporating inorganic fillers into polymer matrices[1].However,the random distri...High-performance lithium metal batteries benefit from the construction of composite polymer electrolytes(CPEs)which are synthesized by incorporating inorganic fillers into polymer matrices[1].However,the random distribution of added fillers within the polymer matrix can lead to tortuous ion pathways and longer transmission distances(Fig.1).As a result,the ion transport capability of CPEs may decrease,while interface contact may deteriorate.Therefore,the organized arrangement of fillers emerges as a crucial consideration in constructing electrolyte membranes.One highly effective approach is the adoption of a vertically aligned filler configuration,where ceramic fillers are constructed to be perpendicular to the electrolyte membrane.If so,the filler/electrolyte interface impedance can be significantly reduced,while continuous ion transport channels along the specified direction are formed,thus significantly enhancing the ion conduction(Fig.1(a))[1].展开更多
Molecular high-order harmonic spectroscopy is a significant advancement in ultrafast science, enabling the measurement of multielectron dynamics with attosecond temporal resolution. The fine structures observed in the...Molecular high-order harmonic spectroscopy is a significant advancement in ultrafast science, enabling the measurement of multielectron dynamics with attosecond temporal resolution. The fine structures observed in the molecular harmonic spectrum provide crucial insights into the structural or multielectron dynamical effects induced by intense laser fields. In this study, we measure the high-order harmonic spectrum of aligned CO_(2) molecules contributed from short trajectories. Two distinct groups of minima are identified in the plateau region. Our findings indicate that the deeper-lying molecular orbitals and two-center interference play significant roles in molecular harmonic generation. The results pave the way for advancing the understanding of multielectron dynamics in polyatomic molecules under intense laser fields.展开更多
Solid oxide fuel cells(SOFCs)are widely presented as a sustainable solution to future energy challenges.Nevertheless,solid oxide fuel cells presently rely on significant use of several critical raw materials to enable...Solid oxide fuel cells(SOFCs)are widely presented as a sustainable solution to future energy challenges.Nevertheless,solid oxide fuel cells presently rely on significant use of several critical raw materials to enable optimized electrode reaction kinetics.This challenge can be addressed by using thinfilm electrode materials;however,this is typically accompanied by complex device fabrication procedures as well as poor mechanical/chemical stability.In this work,we conduct a systematic study of a range of promising thin-film electrode materials based on vertically aligned nanocomposite(VAN)thin films.We demonstrate low area specific resistance(ASR)values of 0.44 cm^(2) at 650℃ can be achieved using(La_(0.60)Sr_(0.40))_(0.95)Co_(0.20)Fe_(0.80)O_(3)-(Sm_(2)O_(3))_(0.20)(CeO_(2))_(0.80)(LSCF-SDC)thin films,which are also characterized by a low degradation rate,approximately half that of planar LSCF thin films.We then integrate these(La_(0.60)Sr_(0.40))_(0.95)Co_(0.20)Fe_(0.80)O_(3)-(Sm_(2)O_(3))_(0.20)(CeO_(2))_(0.80) vertically aligned nanocomposite films directly with commercial anode supported half cells through a single-step deposition process.The resulting cells exhibit peak power density of 0.47W cm^(-2) at 750℃,competitive with 0.64W cm^(-2) achieved for the same cells operating with a bulk(La_(0.60)Sr_(0.40))_(0.95)Co_(0.20)Fe_(0.80)O_(3) cathode,despite 99.5% reduction in cathode critical raw material use.By demonstrating such competitive performance using thin-film cathode functional layers,this work also paves the way for further cost reductions in solid oxide fuel cells,which could be achieved by likewise applying thin-film architectures to the anode functional layer and/or current collecting layers,which typically account for the greatest materials cost in solid oxide fuel cell stacks.Therefore,the present work marks a valuable step towards the sustainable proliferation of solid oxide fuel cells.展开更多
Stemming from the unique in-plane honeycomb lattice structure and the sp^(2)hybridized carbon atoms bonded by exceptionally strong carbon–carbon bonds,graphene exhibits remarkable anisotropic electrical,mechanical,an...Stemming from the unique in-plane honeycomb lattice structure and the sp^(2)hybridized carbon atoms bonded by exceptionally strong carbon–carbon bonds,graphene exhibits remarkable anisotropic electrical,mechanical,and thermal properties.To maximize the utilization of graphene’s in-plane properties,pre-constructed and aligned structures,such as oriented aerogels,films,and fibers,have been designed.The unique combination of aligned structure,high surface area,excellent electrical conductivity,mechanical stability,thermal conductivity,and porous nature of highly aligned graphene aerogels allows for tailored and enhanced performance in specific directions,enabling advancements in diverse fields.This review provides a comprehensive overview of recent advances in highly aligned graphene aerogels and their composites.It highlights the fabrication methods of aligned graphene aerogels and the optimization of alignment which can be estimated both qualitatively and quantitatively.The oriented scaffolds endow graphene aerogels and their composites with anisotropic properties,showing enhanced electrical,mechanical,and thermal properties along the alignment at the sacrifice of the perpendicular direction.This review showcases remarkable properties and applications of aligned graphene aerogels and their composites,such as their suitability for electronics,environmental applications,thermal management,and energy storage.Challenges and potential opportunities are proposed to offer new insights into prospects of this material.展开更多
P-and SV-wave dispersion and attenuation have been extensively investigated in saturated poroelastic media with aligned fractures.However,there are few existing models that incorporate the multiple wave attenuation me...P-and SV-wave dispersion and attenuation have been extensively investigated in saturated poroelastic media with aligned fractures.However,there are few existing models that incorporate the multiple wave attenuation mechanisms from the microscopic scale to the macroscopic scale.Hence,in this work,we developed a unified model to incorporate the wave attenuation mechanisms at different scales,which includes the microscopic squirt flow between the microcracks and pores,the mesoscopic wave-induced fluid flow between fractures and background(FB-WIFF),and the macroscopic Biot's global flow and elastic scattering(ES)from the fractures.Using Tang's modified Biot's theory and the mixed-boundary conditions,we derived the exact frequency-dependent solutions of the scattering problem for a single penny-shaped fracture with oblique incident P-and SV-waves.We then developed theoretical models for a set of aligned fractures and randomly oriented fractures using the Foldy approximation.The results indicated that microcrack squirt flow considerably influences the dispersion and attenuation of P-and SV-wave velocities.The coupling effects of microcrack squirt flow with the FB-WIFF and ES of fractures cause much higher velocity dispersion and attenuation for P waves than for SV waves.Randomly oriented fractures substantially reduce the attenuation caused by the FB-WIFF and ES,particularly for the ES attenuation of SV waves.Through a comparison with existing models in the limiting cases and previous experimental measurements,we validated our model.展开更多
Phase change materials(PCMs)are widely considered as promising energy storage materials for solar/electro-thermal energy storage.Nevertheless,the inherent low thermal/electrical conductivities of most PCMs limit their...Phase change materials(PCMs)are widely considered as promising energy storage materials for solar/electro-thermal energy storage.Nevertheless,the inherent low thermal/electrical conductivities of most PCMs limit their energy conversion efficiencies,hindering their practical applications.Herein,we fabricate a highly thermally/electrically conductive solid-solid phase change composite(PCC)enabled by forming aligned graphite networks through pressing the mixture of the trimethylolethane and porous expanded graphite(EG).Experiments indicate that both the thermal and electrical conductivities of the PCC increase with increasing mass proportion of the EG because the aligned graphite networks establish highly conductive pathways.Meanwhile,the PCC4 sample with the EG proportion of 20wt%can achieve a high thermal conductivity of 12.82±0.38W·m^(-1)·K^(-1)and a high electrical conductivity of 4.11±0.02S·cm^(-1)in the lengthwise direction.Furthermore,a solar-thermal energy storage device incorporating the PCC4,a solar selective absorber,and a highly transparent glass is developed,which reaches a high solar-thermal efficiency of 77.30±2.71%under 3.0 suns.Moreover,the PCC4 can also reach a high electro-thermal efficiency of 91.62±3.52%at a low voltage of 3.6V,demonstrating its superior electro-thermal storage performance.Finally,stability experiments indicate that PCCs exhibit stabilized performance in prolonged TES operations.Overall,this work offers highly conductive and cost-effective PCCs,which are suitable for large-scale and efficient solar/electro-thermal energy storage.展开更多
High performance 1 57μm spotsize converter monolithically integrated DFB is fabricated by the technique of self aligned selective area growth.The upper optical confinement layer and the butt coupled tapered thickn...High performance 1 57μm spotsize converter monolithically integrated DFB is fabricated by the technique of self aligned selective area growth.The upper optical confinement layer and the butt coupled tapered thickness waveguide are regrown simultaneously,which not only offeres the separated optimization of the active region and the integrated spotsize converter,but also reduces the difficulty of the butt joint selective regrowth.The threshold current is as low as 4 4mA.The output power at 49mA is 10 1mW.The side mode suppression ratio (SMSR) is 33 2dB.The vertical and horizontal far field divergence angles are as small as 9° and 15° respectively,the 1dB misalignment tolerance are 3 6μm and 3 4μm.展开更多
A self aligned InGaP/GaAs power HBTs for L band power amplifier with low bias voltage are described.Base emitter metal self aligning,air bridge,and wafer thinning are used to improve microwave power performance.A...A self aligned InGaP/GaAs power HBTs for L band power amplifier with low bias voltage are described.Base emitter metal self aligning,air bridge,and wafer thinning are used to improve microwave power performance.A power HBT with double size of emitter of (3μm×15μm)×12 is fabricated.When the packaged HBT operates in class AB at a collector bias of 3V,a maximum 23dBm output power with 45% power added efficiency is achieved at 2GHz.The results show that the InGaP/GaAs power HBTs have great potential in mobile communication systems operating at low bias voltage.展开更多
Ultrathin,lightweight,and flexible aligned single-walled carbon nanotube(SWCNT)films are fabricated by a facile,environmentally friendly,and scalable printing methodology.The aligned pattern and outstanding intrinsic ...Ultrathin,lightweight,and flexible aligned single-walled carbon nanotube(SWCNT)films are fabricated by a facile,environmentally friendly,and scalable printing methodology.The aligned pattern and outstanding intrinsic properties render“metal-like”thermal conductivity of the SWCNT films,as well as excellent mechanical strength,flexibility,and hydrophobicity.Further,the aligned cellular microstructure promotes the electromagnetic interference(EMI)shielding ability of the SWCNTs,leading to excellent shielding effectiveness(SE)of~39 to 90 dB despite a density of only~0.6 g cm^(−3) at thicknesses of merely 1.5-24μm,respectively.An ultrahigh thickness-specific SE of 25693 dB mm^(−1) and an unprecedented normalized specific SE of 428222 dB cm^(2)g^(−1) are accomplished by the freestanding SWCNT films,significantly surpassing previously reported shielding materials.In addition to an EMI SE greater than 54 dB in an ultra-broadband frequency range of around 400 GHz,the films demonstrate excellent EMI shielding stability and reliability when subjected to mechanical deformation,chemical(acid/alkali/organic solvent)corrosion,and high-/low-temperature environments.The novel printed SWCNT films offer significant potential for practical applications in the aerospace,defense,precision components,and smart wearable electronics industries.展开更多
Extensive experimental studies on the heat transfer characteristics of two rows of aligned jet holes impinging on a concave surface in a wing leading edge were conducted, where50000 Rej 90000, 1.74 H/d 27.5, 66° ...Extensive experimental studies on the heat transfer characteristics of two rows of aligned jet holes impinging on a concave surface in a wing leading edge were conducted, where50000 Rej 90000, 1.74 H/d 27.5, 66° a 90°, and 13.2 r/d 42.03. The finding was that the heat transfer performance at the jet-impingement stagnation point with two rows of aligned jet holes was the same as that with a single row of jet holes or the middle row of three-row configurations when the circumferential angle of the two jet holes was larger than 30°. The attenuation coefficient distribution of the jet impingement heat transfer in the chordwise direction was so complicated that two zones were divided for a better analysis. It indicated that： the attenuation coefficient curve in the jet impingement zone exhibited an approximate upside-down bell shape with double peaks and a single valley; the attenuation coefficient curve in the non-jet impingement zone was like a half-bell shape, which was similar to that with three rows of aligned jet holes; the factors,including Rej, H/d and r/d, affected the attenuation coefficient value at the valley significantly.When r/d was increased from 30.75 to 42.03, the attenuation rates of attenuation coefficient increased only by 1.8%. Consequently, experimental data-based correlation equations of the Nusselt number for the heat transfer at the jet-impingement stagnation point and the distributionof the attenuation coefficient in the chordwise direction were acquired, which play an important role in designing the wing leading edge anti-icing system with two rows of aligned jet holes.展开更多
Encoding information in light polarization is of great importance in facilitating optical data storage(ODS)for information security and data storage capacity escalation.However,despite recent advances in nanophotonic ...Encoding information in light polarization is of great importance in facilitating optical data storage(ODS)for information security and data storage capacity escalation.However,despite recent advances in nanophotonic techniques vastly en-hancing the feasibility of applying polarization channels,the data fidelity in reconstructed bits has been constrained by severe crosstalks occurring between varied polarization angles during data recording and reading process,which gravely hindered the utilization of this technique in practice.In this paper,we demonstrate an ultra-low crosstalk polarization-en-coding multilayer ODS technique for high-fidelity data recording and retrieving by utilizing a nanofibre-based nanocom-posite film involving highly aligned gold nanorods(GNRs).With parallelizing the gold nanorods in the recording medium,the information carrier configuration minimizes miswriting and misreading possibilities for information input and output,respectively,compared with its randomly self-assembled counterparts.The enhanced data accuracy has significantly im-proved the bit recall fidelity that is quantified by a correlation coefficient higher than 0.99.It is anticipated that the demon-strated technique can facilitate the development of multiplexing ODS for a greener future.展开更多
A new substrate,aligned Ag nanowires decorated with silver nanoparticle composite structure(AgNWs@AgNPs),was fabricated to investigate metalenhanced fluorescence(MEF) and its mechanism.The new composite structure was ...A new substrate,aligned Ag nanowires decorated with silver nanoparticle composite structure(AgNWs@AgNPs),was fabricated to investigate metalenhanced fluorescence(MEF) and its mechanism.The new composite structure was fabricated via a three-phase interface assembly method followed by SnCl2 sensitization and AgNO3 reduction process.The size and distribution of the nanoparticles on silver nanowires increased with the sensitization and reduction cycles.The formation of AgNPs on the surfaces of AgNWs was confirmed by multiple characterization methods including scanning electron microscopy(SEM),transmission electron microscope(TEM),atomic force microscopy(AFM) and X-ray diffraction(XRD).The results show that the fluorescence intensity of the poly(3-hexylthiophene)(P3HT) on the composite structure was greatly enhanced compared with that on bare glass substrate,and the intensity increased with the increase in particle sizes and density.The mechanism was basedo n the increase in excitation rate and the radiation decay rate.The new type of substrate could serve as a good and efficient MEF substrate for high-performance fluorescence-based devices.展开更多
Currently,most rock physics models,used for evaluating the elastic properties of cracked or fractured media,take into account the crack properties,but not the background anisotropy.This creats the errors of in the ani...Currently,most rock physics models,used for evaluating the elastic properties of cracked or fractured media,take into account the crack properties,but not the background anisotropy.This creats the errors of in the anisotropy estimates by using fi eld logging data.In this work,based on the scattered wavefi eld theory,a sphere-equivalency method of elastic wave scattering was developed to accurately calculate the elastic properties of a vertical transversely isotropic solid containing aligned cracks.By setting the scattered wavefi eld due to a crack equal to that due to an equivalent sphere,an eff ective elastic stiff ness tensor was derived for the cracked medium.The stability and accuracy of the approach were determined for varying background anisotropy values.The results show that the anisotropy of the eff ective media is aff ected by cracks and background anisotropy for transversely isotropic background permeated by horizontally aligned cracks,especially for the elastic wave propagating along the horizontal direction.Meanwhile,the crack orientation has a signifi cant infl uence on the elastic wave velocity anisotropy.The theory was subsequently applied to model laboratory ultrasonic experimental data for artifi cially cracked samples and to model borehole acoustic anisotropy measurements.After considering the background anisotropy,the model shows an improvement in the agreement between theoretical predictions and measurement data,demonstrating that the present theory can adequately explain the anisotropic characteristics of cracked media.展开更多
MXene nanomaterials are one of the most promising electrode material candidates for supercapacitors owing to their high conductivity,abundant surface functional groups and large surface area.However,electrodes based o...MXene nanomaterials are one of the most promising electrode material candidates for supercapacitors owing to their high conductivity,abundant surface functional groups and large surface area.However,electrodes based on MXene may result in low ion-accessible surface area and blocked ion transport pathways because of the self-restacking of MXene nanosheets.It is essential to suppress the self-res tacking of nanosheets and increase the electrochemical active sites in order to optimize the electrode.In this work,bidirectionally aligned MXene hybrid aerogel(A-MHA)assembled with MXene nanosheets and microgels is prepared using a facile bidirectional freeze casting and freeze-drying method.The bidirectionally aligned structure together with the three-dimensional structured microgels in the A-MHAs,can improve the ionaccessible surface area and provide more barrier-free channels by exposing more active sites and ensuring electrolyte transport freely.The A-MHA with MXene microgels content of 40 wt%exhibits a high specific capacitance of 760 F·g^(-1)at 1 A·g^(-1)and a remarkable cyclic performance of 97%after 10,000 cycles at100 mV·s^(-1)in 1 mol·L^(-1)H_(2)SO_(4)electrolyte.A-MHAs show remarkable electrochemical properties and are of potential application in energy storage.展开更多
The development of non-noble-metal hydrogen evolution electrocatalysts holds great promises for a sustainable energy system.Here,a hybrid W(Mo)S_(2)/NW(Mo)C nanosheet with array structures was reported for an efficien...The development of non-noble-metal hydrogen evolution electrocatalysts holds great promises for a sustainable energy system.Here,a hybrid W(Mo)S_(2)/NW(Mo)C nanosheet with array structures was reported for an efficient light-as sis ted hydrogen evolution electrocatalysts in acidic solutions.The resulting vertically aligned W(Mo)S_(2)/N-W(Mo)C was supported on a conductive carbon fiber paper,which can be produced through annealing W(Mo)S_(2)nanosheets by simultaneous carbonization and N-doping in Ar/H_(2)atmosphere.This optimized WS_(2)/NWC and MoS_(2)/N-MoC electrode exhibits remarkable lightassisted electrocatalysis activity with overpotentials of0.120 and 0.122 V at 10 mA·cm^(-1)in acidic solutions,respectively.Such high hydrogen evolution activities should be attributed to the electrocatalytic synergistic effects of the abundant active sites existing in different phase boundaries and the absorption for ultraviolet-visible light.This study shows that synthesis of low-cost and highly active W(Mo)S_(2)-based hydrogen evolution electrocatalyst opens up a route toward the development of scalable production of hydrogen fuels.展开更多
Nerve conduits enhance nerve regeneration in the repair of long-distance peripheral nerve defects. To help optimize the effectiveness of nerve conduits for nerve repair, we developed a multi-step electrospinning proce...Nerve conduits enhance nerve regeneration in the repair of long-distance peripheral nerve defects. To help optimize the effectiveness of nerve conduits for nerve repair, we developed a multi-step electrospinning process for constructing nerve guide conduits with aligned nanofibers. The alignment of the nerve guide conduits was characterized by scanning electron microscopy and fast Fourier transform. The mechanical performance of the nerve guide conduits was assessed by testing for tensile strength and compression resistance. The biological performance of the aligned fibers was examined using Schwann cells, PC12 cells and dorsal root ganglia in vitro. Immunohistochemistry was performed for the Schwann cell marker S100 and for the neurofilament protein NF200 in PC12 cells and dorsal root ganglia. In the in vivo experiment, a 1.5-cm defect model of the right sciatic nerve in adult female Sprague-Dawley rats was produced and bridged with an aligned nerve guide conduit. Hematoxylin-eosin staining and immunohistochemistry were used to observe the expression of ATF3 and cleaved caspase-3 in the regenerating matrix. The recovery of motor function was evaluated using the static sciatic nerve index. The number of myelinated fibers, axon diameter, fiber diameter, and myelin thickness in the distal nerve were observed by electron microscopy. Gastrocnemius muscle mass ratio was also determined. The analyses revealed that aligned nanofiber nerve guide conduits have good mechanical properties and can induce Schwann cells, PC12 cells and dorsal root ganglia to aggregate along the length of the nanofibers, and promote the growth of longer axons in the latter two(neuronal) cell types. The aligned fiber nerve conduits increased the expression of ATF3 and cleaved caspase-3 at the middle of the regenerative matrix and at the distal nerve segment, improved sciatic nerve function, increased muscle mass of the gastrocnemius muscle, and enhanced recovery of distal nerve ultrastructure. Collectively, the results show that highly aligned nanofibers improve the performance of the nerve conduit bridge, and enhance its effectiveness in repairing peripheral nerve defects.展开更多
Reducing a Pt loading with improved power output and durability is essential to promote the large-scale application of proton exchange membrane fuel cells(PEMFCs).To achieve this goal,constructing optimized structure ...Reducing a Pt loading with improved power output and durability is essential to promote the large-scale application of proton exchange membrane fuel cells(PEMFCs).To achieve this goal,constructing optimized structure of catalyst layers with efficient mass transportation channels plays a vital role.Herein,PEMFCs with order-structured cathodic electrodes were fabricated by depositing Pt nanoparticles by Ebeam onto vertically aligned carbon nanotubes(VACNTs)growth on Al foil via plasma-enhanced chemical vapor deposition.Results demonstrate that the proportion of hydrophilic Pt-deposited region along VACNTs and residual hydrophobic region of VANCTs without Pt strongly influences the cell performance,in particular at high current densities.When Pt nanoparticles deposit on the top depth of around 600 nm on VACNTs with a length of 4.6μm,the cell shows the highest performance,compared with others with various lengths of VACNTs.It delivers a maximum power output of 1.61 W cm^(-2)(H_(2)/O_(2),150 k Pa)and 0.79 W cm^(-2)(H_(2)/Air,150 k Pa)at Pt loading of 50μg cm^(-2),exceeding most of previously reported PEMFCs with Pt loading of<100μg cm^(-2).Even though the Pt loading is down to 30μg cm^(-2)(1.36 W cm^(-2)),the performance is also better than 100μg cm^(-2)(1.24 W cm^(-2))of commercial Pt/C,and presents better stability.This excellent performance is critical attributed to the ordered hydrophobic region providing sufficient mass passages to facilitate the fast water drainage at high current densities.This work gives a new understanding for oxygen reduction reaction occurred in VACNTs-based ordered electrodes,demonstrating the most possibility to achieve a substantial reduction in Pt loading<100μg cm^(-2) without sacrificing in performance.展开更多
Aligned SnS nanowires arrays were grown via a simple chemical vapor deposition method.As-synthesized SnS nanowires are single crystals grown along the[111]direction.The single SnS nanowire based device showed excellen...Aligned SnS nanowires arrays were grown via a simple chemical vapor deposition method.As-synthesized SnS nanowires are single crystals grown along the[111]direction.The single SnS nanowire based device showed excellent response to near infrared lights with good responsivity of 267.9 A/W,high external quantum efficiency of 3.12×10^4%and fast response time.Photodetectors were built on the aligned SnS nanowire arrays,exhibiting a light on/off ratio of 3.6,and the response and decay time of 4.5 and 0.7 s,respectively,to 1064 nm light illumination.展开更多
基金supported by the National Natural Science Foundation of China(52372099,52202328,22461142135,22479046)the Shanghai Sailing Program(22YF1455500)the Shanghai Magnolia Talent Plan Pujiang Project(24PJD128)。
文摘Solid-state polymer electrolytes are crucial for advancing solid-state lithium-metal batteries owing to their flexibility,excellent manufacturability,and strong interfacial compatibility.However,their widespread applications are hindered by low ionic conductivity at room temperature and lithium dendrite growth.Herein,we report a novel solid-state composite membrane electrolyte design that combines the vertically aligned channel structure and copolymer with a radial gradient composition.Within the vertically aligned channels,the composition of poly(vinyl ethylene carbonate-co-poly(ethylene glycol)diacrylate)(P(VEC-PEGDA)varies in a gradient along the radial direction:from the center to the wall of vertically aligned channels,the proportion of vinyl ethylene carbonate(VEC)in the copolymer decreases,while the proportion of poly(ethylene glycol)diacrylate(PEGDA)increases accordingly.It can be functionally divided into a mechanical-reinforcement layer and a fast-ion-conducting layer.The resulting solid-state composite membrane electrolyte achieves a high critical current density of 1.2 mA cm^(-2)and high ionic conductivity of 2.03 mS cm^(-1)at room temperature.Employing this composite membrane electrolyte,a Li//Li symmetric cell exhibits stable cycling for over 1850 h at 0.2 m A cm^(-2)/0.2 m A h cm^(-2),and a Li//LiFePO4(LFP)battery maintains 77.3% capacity retention at 2 C after 300 cycles.Our work provides insight into the rational design of safer and more efficient solidstate batteries through electrolyte structural engineering.
基金supported by the National Natural Science Foundation of China(No.51972293)Hangzhou Key Research Program Project(2023SZD0099)LingYan Project(2024C01090).
文摘High-performance lithium metal batteries benefit from the construction of composite polymer electrolytes(CPEs)which are synthesized by incorporating inorganic fillers into polymer matrices[1].However,the random distribution of added fillers within the polymer matrix can lead to tortuous ion pathways and longer transmission distances(Fig.1).As a result,the ion transport capability of CPEs may decrease,while interface contact may deteriorate.Therefore,the organized arrangement of fillers emerges as a crucial consideration in constructing electrolyte membranes.One highly effective approach is the adoption of a vertically aligned filler configuration,where ceramic fillers are constructed to be perpendicular to the electrolyte membrane.If so,the filler/electrolyte interface impedance can be significantly reduced,while continuous ion transport channels along the specified direction are formed,thus significantly enhancing the ion conduction(Fig.1(a))[1].
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 92250306 and 12304302)the Natural Science Foundation of Jilin Province, China (Grant Nos. YDZJ202101ZYTS157 and YDZJ202201ZYTS314)the Scientific Research Foundation of Jilin Province Education Department, China (Grant No. JJKH20230283KJ)。
文摘Molecular high-order harmonic spectroscopy is a significant advancement in ultrafast science, enabling the measurement of multielectron dynamics with attosecond temporal resolution. The fine structures observed in the molecular harmonic spectrum provide crucial insights into the structural or multielectron dynamical effects induced by intense laser fields. In this study, we measure the high-order harmonic spectrum of aligned CO_(2) molecules contributed from short trajectories. Two distinct groups of minima are identified in the plateau region. Our findings indicate that the deeper-lying molecular orbitals and two-center interference play significant roles in molecular harmonic generation. The results pave the way for advancing the understanding of multielectron dynamics in polyatomic molecules under intense laser fields.
基金support from the Royal Academy of Engineering Chair in Emerging technologies(grant number CIET1819_24)the EPSRC Centre of Advanced Materials for Integrated Energy Systems(CAM-IES)(grant number EP/P007767/1)+2 种基金the EU-H2020-ERC-ADG EROS(grant number 882929)support provided by Deutsche Forschungsgemeinschaft(Project no.424789449,grant no.HA1344-45-1)support from the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement no.836503.We acknowledge use of the Thermo Fisher Spectra 300 TEM at the Wolfson Electron Microscopy Suite at the University of Cambridge funded by EPSRC under grant EP/R008779/1.
文摘Solid oxide fuel cells(SOFCs)are widely presented as a sustainable solution to future energy challenges.Nevertheless,solid oxide fuel cells presently rely on significant use of several critical raw materials to enable optimized electrode reaction kinetics.This challenge can be addressed by using thinfilm electrode materials;however,this is typically accompanied by complex device fabrication procedures as well as poor mechanical/chemical stability.In this work,we conduct a systematic study of a range of promising thin-film electrode materials based on vertically aligned nanocomposite(VAN)thin films.We demonstrate low area specific resistance(ASR)values of 0.44 cm^(2) at 650℃ can be achieved using(La_(0.60)Sr_(0.40))_(0.95)Co_(0.20)Fe_(0.80)O_(3)-(Sm_(2)O_(3))_(0.20)(CeO_(2))_(0.80)(LSCF-SDC)thin films,which are also characterized by a low degradation rate,approximately half that of planar LSCF thin films.We then integrate these(La_(0.60)Sr_(0.40))_(0.95)Co_(0.20)Fe_(0.80)O_(3)-(Sm_(2)O_(3))_(0.20)(CeO_(2))_(0.80) vertically aligned nanocomposite films directly with commercial anode supported half cells through a single-step deposition process.The resulting cells exhibit peak power density of 0.47W cm^(-2) at 750℃,competitive with 0.64W cm^(-2) achieved for the same cells operating with a bulk(La_(0.60)Sr_(0.40))_(0.95)Co_(0.20)Fe_(0.80)O_(3) cathode,despite 99.5% reduction in cathode critical raw material use.By demonstrating such competitive performance using thin-film cathode functional layers,this work also paves the way for further cost reductions in solid oxide fuel cells,which could be achieved by likewise applying thin-film architectures to the anode functional layer and/or current collecting layers,which typically account for the greatest materials cost in solid oxide fuel cell stacks.Therefore,the present work marks a valuable step towards the sustainable proliferation of solid oxide fuel cells.
基金The financial support by the National Natural Science Foundation of China(No.52002020)is acknowledged.
文摘Stemming from the unique in-plane honeycomb lattice structure and the sp^(2)hybridized carbon atoms bonded by exceptionally strong carbon–carbon bonds,graphene exhibits remarkable anisotropic electrical,mechanical,and thermal properties.To maximize the utilization of graphene’s in-plane properties,pre-constructed and aligned structures,such as oriented aerogels,films,and fibers,have been designed.The unique combination of aligned structure,high surface area,excellent electrical conductivity,mechanical stability,thermal conductivity,and porous nature of highly aligned graphene aerogels allows for tailored and enhanced performance in specific directions,enabling advancements in diverse fields.This review provides a comprehensive overview of recent advances in highly aligned graphene aerogels and their composites.It highlights the fabrication methods of aligned graphene aerogels and the optimization of alignment which can be estimated both qualitatively and quantitatively.The oriented scaffolds endow graphene aerogels and their composites with anisotropic properties,showing enhanced electrical,mechanical,and thermal properties along the alignment at the sacrifice of the perpendicular direction.This review showcases remarkable properties and applications of aligned graphene aerogels and their composites,such as their suitability for electronics,environmental applications,thermal management,and energy storage.Challenges and potential opportunities are proposed to offer new insights into prospects of this material.
基金This work was supported by the Laoshan National Laboratory Science and Technology Innovation Project(No.LSKJ202203407)the National Natural Science Foundation of China(Grant Nos.42174145,41821002,42274146)+1 种基金Guangdong Provincial Key Laboratory of Geophysical High-resolution Imaging Technology(2022B1212010002)Shenzhen Stable Support Plan Program for Higher Education Institutions(20220815110144003).
文摘P-and SV-wave dispersion and attenuation have been extensively investigated in saturated poroelastic media with aligned fractures.However,there are few existing models that incorporate the multiple wave attenuation mechanisms from the microscopic scale to the macroscopic scale.Hence,in this work,we developed a unified model to incorporate the wave attenuation mechanisms at different scales,which includes the microscopic squirt flow between the microcracks and pores,the mesoscopic wave-induced fluid flow between fractures and background(FB-WIFF),and the macroscopic Biot's global flow and elastic scattering(ES)from the fractures.Using Tang's modified Biot's theory and the mixed-boundary conditions,we derived the exact frequency-dependent solutions of the scattering problem for a single penny-shaped fracture with oblique incident P-and SV-waves.We then developed theoretical models for a set of aligned fractures and randomly oriented fractures using the Foldy approximation.The results indicated that microcrack squirt flow considerably influences the dispersion and attenuation of P-and SV-wave velocities.The coupling effects of microcrack squirt flow with the FB-WIFF and ES of fractures cause much higher velocity dispersion and attenuation for P waves than for SV waves.Randomly oriented fractures substantially reduce the attenuation caused by the FB-WIFF and ES,particularly for the ES attenuation of SV waves.Through a comparison with existing models in the limiting cases and previous experimental measurements,we validated our model.
基金supported by the Natural Science Foundation of Hunan Province(No.2024JJ4059)Changsha Outstanding Innovative Youth Training Program(No.kq2306010)+1 种基金National Natural Science Foundation of China(No.52176093)the Central South University Innovation-Driven Research Programme(No.2023CXQD055).
文摘Phase change materials(PCMs)are widely considered as promising energy storage materials for solar/electro-thermal energy storage.Nevertheless,the inherent low thermal/electrical conductivities of most PCMs limit their energy conversion efficiencies,hindering their practical applications.Herein,we fabricate a highly thermally/electrically conductive solid-solid phase change composite(PCC)enabled by forming aligned graphite networks through pressing the mixture of the trimethylolethane and porous expanded graphite(EG).Experiments indicate that both the thermal and electrical conductivities of the PCC increase with increasing mass proportion of the EG because the aligned graphite networks establish highly conductive pathways.Meanwhile,the PCC4 sample with the EG proportion of 20wt%can achieve a high thermal conductivity of 12.82±0.38W·m^(-1)·K^(-1)and a high electrical conductivity of 4.11±0.02S·cm^(-1)in the lengthwise direction.Furthermore,a solar-thermal energy storage device incorporating the PCC4,a solar selective absorber,and a highly transparent glass is developed,which reaches a high solar-thermal efficiency of 77.30±2.71%under 3.0 suns.Moreover,the PCC4 can also reach a high electro-thermal efficiency of 91.62±3.52%at a low voltage of 3.6V,demonstrating its superior electro-thermal storage performance.Finally,stability experiments indicate that PCCs exhibit stabilized performance in prolonged TES operations.Overall,this work offers highly conductive and cost-effective PCCs,which are suitable for large-scale and efficient solar/electro-thermal energy storage.
文摘High performance 1 57μm spotsize converter monolithically integrated DFB is fabricated by the technique of self aligned selective area growth.The upper optical confinement layer and the butt coupled tapered thickness waveguide are regrown simultaneously,which not only offeres the separated optimization of the active region and the integrated spotsize converter,but also reduces the difficulty of the butt joint selective regrowth.The threshold current is as low as 4 4mA.The output power at 49mA is 10 1mW.The side mode suppression ratio (SMSR) is 33 2dB.The vertical and horizontal far field divergence angles are as small as 9° and 15° respectively,the 1dB misalignment tolerance are 3 6μm and 3 4μm.
文摘A self aligned InGaP/GaAs power HBTs for L band power amplifier with low bias voltage are described.Base emitter metal self aligning,air bridge,and wafer thinning are used to improve microwave power performance.A power HBT with double size of emitter of (3μm×15μm)×12 is fabricated.When the packaged HBT operates in class AB at a collector bias of 3V,a maximum 23dBm output power with 45% power added efficiency is achieved at 2GHz.The results show that the InGaP/GaAs power HBTs have great potential in mobile communication systems operating at low bias voltage.
基金support of National Key R&D Program of China (2021YFB3502500)Provincial Key Research and Development Program of Shandong (2019JZZY010312, 2021ZLGX01)+4 种基金Natural Science Foundation of Shandong Province (2022HYYQ-014)New 20 Funded Programs for Universities of Jinan (2021GXRC036)Qilu Young Scholar Program of Shandong University (31370082163127)the assistance of Shandong University Testing and Manufacturing Center for Advanced Materialssupport from the National Science Foundation Engineering Research Center for Power Optimization of Electro Thermal Systems (POETS) under Grant No. EEC 1449548.
文摘Ultrathin,lightweight,and flexible aligned single-walled carbon nanotube(SWCNT)films are fabricated by a facile,environmentally friendly,and scalable printing methodology.The aligned pattern and outstanding intrinsic properties render“metal-like”thermal conductivity of the SWCNT films,as well as excellent mechanical strength,flexibility,and hydrophobicity.Further,the aligned cellular microstructure promotes the electromagnetic interference(EMI)shielding ability of the SWCNTs,leading to excellent shielding effectiveness(SE)of~39 to 90 dB despite a density of only~0.6 g cm^(−3) at thicknesses of merely 1.5-24μm,respectively.An ultrahigh thickness-specific SE of 25693 dB mm^(−1) and an unprecedented normalized specific SE of 428222 dB cm^(2)g^(−1) are accomplished by the freestanding SWCNT films,significantly surpassing previously reported shielding materials.In addition to an EMI SE greater than 54 dB in an ultra-broadband frequency range of around 400 GHz,the films demonstrate excellent EMI shielding stability and reliability when subjected to mechanical deformation,chemical(acid/alkali/organic solvent)corrosion,and high-/low-temperature environments.The novel printed SWCNT films offer significant potential for practical applications in the aerospace,defense,precision components,and smart wearable electronics industries.
基金supported by the National Natural Science Foundation of China (No. 51206008)
文摘Extensive experimental studies on the heat transfer characteristics of two rows of aligned jet holes impinging on a concave surface in a wing leading edge were conducted, where50000 Rej 90000, 1.74 H/d 27.5, 66° a 90°, and 13.2 r/d 42.03. The finding was that the heat transfer performance at the jet-impingement stagnation point with two rows of aligned jet holes was the same as that with a single row of jet holes or the middle row of three-row configurations when the circumferential angle of the two jet holes was larger than 30°. The attenuation coefficient distribution of the jet impingement heat transfer in the chordwise direction was so complicated that two zones were divided for a better analysis. It indicated that： the attenuation coefficient curve in the jet impingement zone exhibited an approximate upside-down bell shape with double peaks and a single valley; the attenuation coefficient curve in the non-jet impingement zone was like a half-bell shape, which was similar to that with three rows of aligned jet holes; the factors,including Rej, H/d and r/d, affected the attenuation coefficient value at the valley significantly.When r/d was increased from 30.75 to 42.03, the attenuation rates of attenuation coefficient increased only by 1.8%. Consequently, experimental data-based correlation equations of the Nusselt number for the heat transfer at the jet-impingement stagnation point and the distributionof the attenuation coefficient in the chordwise direction were acquired, which play an important role in designing the wing leading edge anti-icing system with two rows of aligned jet holes.
基金financial supports from the National Natural Science Foundation of China(Grant Nos.62174073,61875073,11674130,91750110 and 61522504)the National Key R&D Program of China(Grant No.2018YFB1107200)+3 种基金the Guangdong Provincial Innovation and Entrepren-eurship Project(Grant No.2016ZT06D081)the Natural Science Founda-tion of Guangdong Province,China(Grant Nos.2016A030306016 and 2016TQ03X981)the Pearl River Nova Program of Guangzhou(Grant No.201806010040)the Technology Innovation and Development Plan of Yantai(Grant No.2020XDRH095).
文摘Encoding information in light polarization is of great importance in facilitating optical data storage(ODS)for information security and data storage capacity escalation.However,despite recent advances in nanophotonic techniques vastly en-hancing the feasibility of applying polarization channels,the data fidelity in reconstructed bits has been constrained by severe crosstalks occurring between varied polarization angles during data recording and reading process,which gravely hindered the utilization of this technique in practice.In this paper,we demonstrate an ultra-low crosstalk polarization-en-coding multilayer ODS technique for high-fidelity data recording and retrieving by utilizing a nanofibre-based nanocom-posite film involving highly aligned gold nanorods(GNRs).With parallelizing the gold nanorods in the recording medium,the information carrier configuration minimizes miswriting and misreading possibilities for information input and output,respectively,compared with its randomly self-assembled counterparts.The enhanced data accuracy has significantly im-proved the bit recall fidelity that is quantified by a correlation coefficient higher than 0.99.It is anticipated that the demon-strated technique can facilitate the development of multiplexing ODS for a greener future.
基金financially supported by the National Natural Science Foundation of China (No.51273048)Science and Technology Planning Project of Guangdong Province (No.2017B090915004)the Open Operation of Guangdong Provincial Key Laboratory of Advanced Coatings Research and Development (No.2017B030314105)
文摘A new substrate,aligned Ag nanowires decorated with silver nanoparticle composite structure(AgNWs@AgNPs),was fabricated to investigate metalenhanced fluorescence(MEF) and its mechanism.The new composite structure was fabricated via a three-phase interface assembly method followed by SnCl2 sensitization and AgNO3 reduction process.The size and distribution of the nanoparticles on silver nanowires increased with the sensitization and reduction cycles.The formation of AgNPs on the surfaces of AgNWs was confirmed by multiple characterization methods including scanning electron microscopy(SEM),transmission electron microscope(TEM),atomic force microscopy(AFM) and X-ray diffraction(XRD).The results show that the fluorescence intensity of the poly(3-hexylthiophene)(P3HT) on the composite structure was greatly enhanced compared with that on bare glass substrate,and the intensity increased with the increase in particle sizes and density.The mechanism was basedo n the increase in excitation rate and the radiation decay rate.The new type of substrate could serve as a good and efficient MEF substrate for high-performance fluorescence-based devices.
基金supported by the National Natural Science Foundation of China (No. 41821002)the Fundamental Research Funds for the Central Universities (Nos. 18CX02065A,20CX06046A)+3 种基金the Young Elite Scientist Sponsorship Program by the China Association for Science and TechnologyMajor Scientifi c and Technological Projects of CNPC (No. ZD2019-183-004)Qingdao Postdoctoral Applied Research Project (No. qdyy20190079)China Postdoctoral Science Foundation (No. 2020M672171)。
文摘Currently,most rock physics models,used for evaluating the elastic properties of cracked or fractured media,take into account the crack properties,but not the background anisotropy.This creats the errors of in the anisotropy estimates by using fi eld logging data.In this work,based on the scattered wavefi eld theory,a sphere-equivalency method of elastic wave scattering was developed to accurately calculate the elastic properties of a vertical transversely isotropic solid containing aligned cracks.By setting the scattered wavefi eld due to a crack equal to that due to an equivalent sphere,an eff ective elastic stiff ness tensor was derived for the cracked medium.The stability and accuracy of the approach were determined for varying background anisotropy values.The results show that the anisotropy of the eff ective media is aff ected by cracks and background anisotropy for transversely isotropic background permeated by horizontally aligned cracks,especially for the elastic wave propagating along the horizontal direction.Meanwhile,the crack orientation has a signifi cant infl uence on the elastic wave velocity anisotropy.The theory was subsequently applied to model laboratory ultrasonic experimental data for artifi cially cracked samples and to model borehole acoustic anisotropy measurements.After considering the background anisotropy,the model shows an improvement in the agreement between theoretical predictions and measurement data,demonstrating that the present theory can adequately explain the anisotropic characteristics of cracked media.
基金financially supported by the National Natural Science Foundation of China(No.52002354)China Postdoctoral Science Foundation(No.2020M672256)。
文摘MXene nanomaterials are one of the most promising electrode material candidates for supercapacitors owing to their high conductivity,abundant surface functional groups and large surface area.However,electrodes based on MXene may result in low ion-accessible surface area and blocked ion transport pathways because of the self-restacking of MXene nanosheets.It is essential to suppress the self-res tacking of nanosheets and increase the electrochemical active sites in order to optimize the electrode.In this work,bidirectionally aligned MXene hybrid aerogel(A-MHA)assembled with MXene nanosheets and microgels is prepared using a facile bidirectional freeze casting and freeze-drying method.The bidirectionally aligned structure together with the three-dimensional structured microgels in the A-MHAs,can improve the ionaccessible surface area and provide more barrier-free channels by exposing more active sites and ensuring electrolyte transport freely.The A-MHA with MXene microgels content of 40 wt%exhibits a high specific capacitance of 760 F·g^(-1)at 1 A·g^(-1)and a remarkable cyclic performance of 97%after 10,000 cycles at100 mV·s^(-1)in 1 mol·L^(-1)H_(2)SO_(4)electrolyte.A-MHAs show remarkable electrochemical properties and are of potential application in energy storage.
基金financially supported by the National Natural Science Foundation of China(No.52202340)China Postdoctoral Science Foundation(No.2021M691365)+2 种基金the Applied Basic Research Project of Shanxi Province(No.20210302124425)the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(No.2021L266)the Graduate Science and Technology Innovation Project Foundation of Shanxi Normal University(No.2021XSY030)。
文摘The development of non-noble-metal hydrogen evolution electrocatalysts holds great promises for a sustainable energy system.Here,a hybrid W(Mo)S_(2)/NW(Mo)C nanosheet with array structures was reported for an efficient light-as sis ted hydrogen evolution electrocatalysts in acidic solutions.The resulting vertically aligned W(Mo)S_(2)/N-W(Mo)C was supported on a conductive carbon fiber paper,which can be produced through annealing W(Mo)S_(2)nanosheets by simultaneous carbonization and N-doping in Ar/H_(2)atmosphere.This optimized WS_(2)/NWC and MoS_(2)/N-MoC electrode exhibits remarkable lightassisted electrocatalysis activity with overpotentials of0.120 and 0.122 V at 10 mA·cm^(-1)in acidic solutions,respectively.Such high hydrogen evolution activities should be attributed to the electrocatalytic synergistic effects of the abundant active sites existing in different phase boundaries and the absorption for ultraviolet-visible light.This study shows that synthesis of low-cost and highly active W(Mo)S_(2)-based hydrogen evolution electrocatalyst opens up a route toward the development of scalable production of hydrogen fuels.
基金supported by the National Natural Science Foundation of China,No.31771052(to YW)the National Basic Research Program of China(973 Program),No.2014CB542201(to JP)+4 种基金the National Key Research and Development Program of China,No.2016YFC1101601(to QZ),2017YFA0104702(to YW)the PLA General Hospital Translational Medicine Project of China,No.2016TM-030(to QZ)the Beijing Municipal Natural Science Foundation of China,No.7172202(to YW)the PLA Youth Training Project for Medical Science,China,No.16QNP144(to YW)the Beijing Municipal Science and Technology Project,China,No.Z161100005016059(to YW)
文摘Nerve conduits enhance nerve regeneration in the repair of long-distance peripheral nerve defects. To help optimize the effectiveness of nerve conduits for nerve repair, we developed a multi-step electrospinning process for constructing nerve guide conduits with aligned nanofibers. The alignment of the nerve guide conduits was characterized by scanning electron microscopy and fast Fourier transform. The mechanical performance of the nerve guide conduits was assessed by testing for tensile strength and compression resistance. The biological performance of the aligned fibers was examined using Schwann cells, PC12 cells and dorsal root ganglia in vitro. Immunohistochemistry was performed for the Schwann cell marker S100 and for the neurofilament protein NF200 in PC12 cells and dorsal root ganglia. In the in vivo experiment, a 1.5-cm defect model of the right sciatic nerve in adult female Sprague-Dawley rats was produced and bridged with an aligned nerve guide conduit. Hematoxylin-eosin staining and immunohistochemistry were used to observe the expression of ATF3 and cleaved caspase-3 in the regenerating matrix. The recovery of motor function was evaluated using the static sciatic nerve index. The number of myelinated fibers, axon diameter, fiber diameter, and myelin thickness in the distal nerve were observed by electron microscopy. Gastrocnemius muscle mass ratio was also determined. The analyses revealed that aligned nanofiber nerve guide conduits have good mechanical properties and can induce Schwann cells, PC12 cells and dorsal root ganglia to aggregate along the length of the nanofibers, and promote the growth of longer axons in the latter two(neuronal) cell types. The aligned fiber nerve conduits increased the expression of ATF3 and cleaved caspase-3 at the middle of the regenerative matrix and at the distal nerve segment, improved sciatic nerve function, increased muscle mass of the gastrocnemius muscle, and enhanced recovery of distal nerve ultrastructure. Collectively, the results show that highly aligned nanofibers improve the performance of the nerve conduit bridge, and enhance its effectiveness in repairing peripheral nerve defects.
基金finically supported by the National Natural Science Foundation of China(22075055)the Guangxi Science and Technology Project(AB16380030)the Innovation Project of Guangxi Graduate Education(YCSW2020052)。
文摘Reducing a Pt loading with improved power output and durability is essential to promote the large-scale application of proton exchange membrane fuel cells(PEMFCs).To achieve this goal,constructing optimized structure of catalyst layers with efficient mass transportation channels plays a vital role.Herein,PEMFCs with order-structured cathodic electrodes were fabricated by depositing Pt nanoparticles by Ebeam onto vertically aligned carbon nanotubes(VACNTs)growth on Al foil via plasma-enhanced chemical vapor deposition.Results demonstrate that the proportion of hydrophilic Pt-deposited region along VACNTs and residual hydrophobic region of VANCTs without Pt strongly influences the cell performance,in particular at high current densities.When Pt nanoparticles deposit on the top depth of around 600 nm on VACNTs with a length of 4.6μm,the cell shows the highest performance,compared with others with various lengths of VACNTs.It delivers a maximum power output of 1.61 W cm^(-2)(H_(2)/O_(2),150 k Pa)and 0.79 W cm^(-2)(H_(2)/Air,150 k Pa)at Pt loading of 50μg cm^(-2),exceeding most of previously reported PEMFCs with Pt loading of<100μg cm^(-2).Even though the Pt loading is down to 30μg cm^(-2)(1.36 W cm^(-2)),the performance is also better than 100μg cm^(-2)(1.24 W cm^(-2))of commercial Pt/C,and presents better stability.This excellent performance is critical attributed to the ordered hydrophobic region providing sufficient mass passages to facilitate the fast water drainage at high current densities.This work gives a new understanding for oxygen reduction reaction occurred in VACNTs-based ordered electrodes,demonstrating the most possibility to achieve a substantial reduction in Pt loading<100μg cm^(-2) without sacrificing in performance.
基金National Natural Science Foundation of China(61625404,61888102).
文摘Aligned SnS nanowires arrays were grown via a simple chemical vapor deposition method.As-synthesized SnS nanowires are single crystals grown along the[111]direction.The single SnS nanowire based device showed excellent response to near infrared lights with good responsivity of 267.9 A/W,high external quantum efficiency of 3.12×10^4%and fast response time.Photodetectors were built on the aligned SnS nanowire arrays,exhibiting a light on/off ratio of 3.6,and the response and decay time of 4.5 and 0.7 s,respectively,to 1064 nm light illumination.
