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Engineering hollow core-shell hetero-structure box to induce interfacial charge modulation for promoting bidirectional sulfur conversion in lithium-sulfur batteries 被引量:3
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作者 Weiliang Zhou Xinying Wang +5 位作者 Jiongwei Shan Liguo Yue Dongzhen Lu Li Chen Jiacheng Zhang Yunyong Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第5期128-139,I0004,共13页
Severe polysulfide shuttling and sluggish sulfur redox kinetics significantly decrease sulfur utilization and cycling stability in lithium-sulfur batteries(LSBs).Herein,we develop a hollow CoO/CoP-Box core-shell heter... Severe polysulfide shuttling and sluggish sulfur redox kinetics significantly decrease sulfur utilization and cycling stability in lithium-sulfur batteries(LSBs).Herein,we develop a hollow CoO/CoP-Box core-shell heterostructure as a model and multifunctional catalyst modified on separators to induce interfacial charge modulation and expose more active sites for promoting the adsorption and catalytic conversion ability of sulfur species.Theoretical and experimental findings verify that the in-situ formed core-shell hetero-interface induces the formation of P-Co-O binding and charge redistribution to activate surface O active sites for binding lithium polysulfides(LiPSs)via strong Li-O bonding,thus strongly adsorbing with Li PSs.Meanwhile,the strong Li-O bonding weakens the competing Li-S bonding in LiPSs or Li2S adsorbed on CoO/CoP-Box surface,plus the hollow heterostructure provides abundant active sites and fast electron/Li+transfer,so reducing Li2S nucleation/dissolution activation energy.As expected,LSBs with CoO/CoP-Box modified separator and traditional sulfur/carbon black cathode display a large initial capacity of 1240 mA h g^(-1)and a long cycling stability with 300 cycles(~60.1%capacity retention)at 0.5C.Impressively,the thick sulfur cathode(sulfur loading:5.2 mg cm^(-2))displays a high initial areal capacity of 6.9 mA h cm^(-2).This work verifies a deep mechanism understanding and an effective strategy to induce interfacial charge modulation and enhance active sites for designing efficient dual-directional Li-S catalysts via engineering hollow core-shell hetero-structure. 展开更多
关键词 CoO/CoP-Box Hollow core-shell hetero-structure Multifunctional catalysts Interfacial charge modulation Lithium sulfur batteries
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Effect of Lattice Mismatch on Luminescence of ZnO/Si Hetero-Structure 被引量:2
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作者 傅竹西 孙贤开 +1 位作者 朱俊杰 林碧霞 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2006年第2期239-244,共6页
The photoluminescence (PL) and Raman spectra of undoped ZnO films deposited directly on Si substrate (sample A),on Si substrate through a SiC buffer layer (sample B),and on a ZnO crystal wafer (sample C) are i... The photoluminescence (PL) and Raman spectra of undoped ZnO films deposited directly on Si substrate (sample A),on Si substrate through a SiC buffer layer (sample B),and on a ZnO crystal wafer (sample C) are investigated. There are emission peaks centered at 3.18eV (ultraviolet,UV) and 2.38eV (green) in these sampies. Comparing the Raman spectra and the variation of the PL peak intensities with annealing atmosphere, we conclude that the luminescence of the samples is related to the tensile strain in the ZnO film due to the lattice mismatch between the film and the substrate. In particular, the tensile strain reduces the formation energy of OZn antisite oxygen defects,which generate the green emission center. After annealing in oxygen-rich atmosphere, many OZn defects are generated. Thus, the intensity of green emission in ZnO/Si hetero-structure materials increases due to tensile strain in ZnO films. 展开更多
关键词 ZnO/Si hetero-structure LUMINESCENCE lattice mismatch biaxial tensile strain
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Thermoelectric-transport in metal/graphene/metal hetero-structure
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作者 胡昊 蔡金明 +7 位作者 张晨栋 高敏 潘毅 杜世萱 孙庆丰 牛谦 谢心澄 高鸿钧 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第3期471-476,共6页
We investigate the thermoelectric-transport properties of metal/graphene/metal hetero-structure. We use a single band tight-binding model to prcsent the two-dimensional electronic band structure of graphene. Using the... We investigate the thermoelectric-transport properties of metal/graphene/metal hetero-structure. We use a single band tight-binding model to prcsent the two-dimensional electronic band structure of graphene. Using the LandauerButticker formula and taking the coupling between graphene and the two electrodes into account, we can calculate the thermoelectric potential and current versus temperature. It is found that in spite of metal electrodes, the carrier type of graphene determines the electron motion direction driven by the difference in temperature between the two electrodes, while for n type graphene, the electrons move along the thermal gradient, and for p type graphene, the electrons move against the thermal gradient. 展开更多
关键词 graphene Landauer-Butticker formula THERMOELECTRICITY hetero-structure
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An Overview of the Multi-Band and the Generalized BCS Equations-Based Approaches to Deal with Hetero-Structured Superconductors
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作者 G. P. Malik 《Open Journal of Microphysics》 2018年第2期7-13,共7页
We trace the conceptual basis of the Multi-Band Approach (MBA) and recall the reasons for its wide following for composite superconductors (SCs). Attention is then drawn to a feature that MBA ignores: the possibility ... We trace the conceptual basis of the Multi-Band Approach (MBA) and recall the reasons for its wide following for composite superconductors (SCs). Attention is then drawn to a feature that MBA ignores: the possibility that electrons in such an SC may also be bound via simultaneous exchanges of quanta with more than one ion-species—a lacuna which is addressed by the Generalized BCS Equations (GBCSEs). Based on several papers, we give a concise account of how this approach: 1) despite employing a single band, meets the criteria satisfied by MBA because a) GBCSEs are derived from a temperature-incorporated Bethe-Salpeter Equation the kernel of which is taken to be a “superpropagator” for a composite SC-each ion-species of which is distinguished by its own Debye temperature and interaction parameter and b) the band overlapping the Fermi surface is allowed to be of variable width. GBCSEs so-obtained reduce to the usual equations for the Tc and Δ of an elemental SC in the limit superpropagator → 1-phonon propagator;2) accommodates moving Cooper pairs and thereby extends the scope of the original BCS theory which restricts the Hamiltonian at the outset to terms that correspond to pairs having zero centre-of-mass momentum. One can now derive an equation for the critical current density (j0) of a composite SC at T = 0 in terms of the Debye temperatures of its ions and their interaction parameters— parameters that also determine its Tc and Δs;3) transforms the problem of optimizing j0 of a composite SC, and hence its Tc, into a problem of chemical engineering;4) provides a common canopy for most composite SCs, including those that are usually regarded as outside the purview of the BCS theory and have therefore been called “exceptional”, e.g., the heavy-fermion SCs;5) incorporates s±-wave superconductivity as an in-built feature and can therefore deal with the iron-based SCs, and 6) leads to presumably verifiable predictions for the values of some relevant parameters, e.g., the effective mass of electrons, for the SCs for which it has been employed. 展开更多
关键词 hetero-structured SUPERCONDUCTORS MULTI-BAND and Generalized BCS Equations-Based APPROACHES Unified Treatment of Cuprates and Fe-Based SUPERCONDUCTORS Quest for Clues about Raising Tc
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Critical role of carbon support in metal nanoaggregate facilitating Fe-N-C catalyst for PEM fuel cell application
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作者 Liming Guo Xin Wan +4 位作者 Qingtao Liu Xiaofang Liu Jiaxiang Shang Ronghai Yu Jianglan Shui 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第10期669-676,I0014,共9页
Metal nanoaggregates can simultaneously enhance the activity and stability of Fe-N-C catalysts in proton-exchange-membrane fuel cells(PEMFC).Previous studies on the relevant mechanism have focused on the direct intera... Metal nanoaggregates can simultaneously enhance the activity and stability of Fe-N-C catalysts in proton-exchange-membrane fuel cells(PEMFC).Previous studies on the relevant mechanism have focused on the direct interaction between FeN_(4)active sites and metal nanoaggregates.However,the role of carbon support that hosts metal nanoaggregates and active sites has been overlooked.Here,a Fe-N-C catalyst encapsulating inactive gold nanoparticles is prepared as a model catalyst to investigate the electronic tuning of Au nanoparticles(NPs)towards the carbon support.Au NPs donate electrons to carbon support,making it rich inπelectrons,which reduces the work function and regulates the electronic configuration of the FeN_(4)sites for an enhanced ORR activity.Meanwhile,the electron-rich carbon support can mitigate the electron depletion of FeN_(4)sites caused by carbon support oxidation,thereby preserving its high activity.The yield and accumulation of H_(2)O_(2)are thus alleviated,which delays the oxidation of the catalyst and benefits the stability.Due to the electron-rich carbon support,the composite catalyst achieves a top-level peak power density of 0.74 W/cm^(2) in a 1.5 bar H_(2)-air PEMFC,as well as the improved stability.This work elucidates the key role of carbon support in the performance enhancement of the FeN-C/metal nanoaggregate composite catalysts for fuel cell application. 展开更多
关键词 Fuel cells Oxygen reduction reaction Fe-N-C hetero-structure catalyst Carbon support
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Thermally conductive polyvinyl alcohol composite films via introducing hetero-structured MXene@silver fillers 被引量:17
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作者 Mukun Li Yuyao Sun +3 位作者 Dianying Feng Kunpeng Ruan Xia Liu Junwei Gu 《Nano Research》 SCIE EI CSCD 2023年第5期7820-7828,共9页
Ag nanoparticles were in-situ grown on the surface of MXene nanosheets to prepare thermally conductive hetero-structured MXene@Ag fillers.With polyvinyl alcohol(PVA)as the polymer matrix,thermally conductive MXene@Ag/... Ag nanoparticles were in-situ grown on the surface of MXene nanosheets to prepare thermally conductive hetero-structured MXene@Ag fillers.With polyvinyl alcohol(PVA)as the polymer matrix,thermally conductive MXene@Ag/PVA composite films were fabricated by the processes of solution blending,pouring,evaporative self-assembly.With the same mass fraction,MXene@Ag-III(MXene/Ag,2:1,w/w)presents more significant improvement in thermal conductivity coefficient(λ)than MXene@Ag,single MXene,Ag,simply blending MXene/Ag.MXene@Ag-III/PVA composite films show dual functions of excellent thermal conductivity and electromagnetic interference(EMI)shielding.When the mass fraction of MXene@Ag-III is 60 wt.%,the in-planeλ(λ_(∥)),through-planeλ(λ_(⊥)),EMI shielding effectiveness(EMI SE)are 3.72 and 0.41 W/(m∙K),32 dB,which are increased by 3.1,1.3,105.7 times than those of pure PVA film(0.91 and 0.18 W/(m∙K),0.3 dB),respectively.The 60 wt.%MXene@Ag-III/PVA composite film also has satisfying mechanical and thermal properties,with Young’s modulus,glass transition temperature,heat resistance index of 3.8 GPa,58.5 and 175.3℃,respectively. 展开更多
关键词 hetero-structured MXene@Ag fillers polyvinyl alcohol composite films thermal conductivity electromagnetic interference shielding
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Research progress of Ag_3PO_4-based photocatalyst: Fundamentals and performance enhancement 被引量:3
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作者 马运柱 成帆 +2 位作者 刘文胜 王娟 王依锴 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第1期112-121,共10页
Ag3PO4 is found to be a highly efficient photocatalyst and receives great attention. The high activity of the photocatalyst is credited to the intrinsic electronic structure. The morphology control and nano-composite ... Ag3PO4 is found to be a highly efficient photocatalyst and receives great attention. The high activity of the photocatalyst is credited to the intrinsic electronic structure. The morphology control and nano-composite fabrication are used to improve the performance and practicability. This paper reviews the structure, properties and some theoretical aspects of Ag3PO4 single crystal. Also, the major strategies, namely the morphology control and hetero-nanostructure construction, as ways to improve the performance of Ag3PO4-based photocatalysts, are summarized with the aid of some typical instances. 展开更多
关键词 Ag3PO4-based photocatalyst electronic structure morphology control hetero-structure construction preparation photocatalytic activity
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A Broadband Long-Wavelength Superluminescent Diode Based on Graded Composition Bulk InGaAs
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作者 丁颖 王圩 +2 位作者 阚强 王宝军 周帆 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2005年第12期2309-2314,共6页
A novel unselective regrowth buried heterostructure long-wavelength superluminescent diode (SLD) with a graded composition bulk InGaAs active region is developed by metalorganic vapor phase epitaxy (MOVPE). At a 1... A novel unselective regrowth buried heterostructure long-wavelength superluminescent diode (SLD) with a graded composition bulk InGaAs active region is developed by metalorganic vapor phase epitaxy (MOVPE). At a 150mA injection current, the full width at half maximum of the emission spectrum of the SLD is about 72nm, ranging from 1602 to 1674nm. The emission spectrum is smooth and flat. The ripple of the spectrum is less than 0.3dB at any wavelength from 1550 to 1700nm. An output power of 4.3mW is obtained at a 200mA injection current under continuous-wave operation at room temperature. This device is suitable for the applications of light sources for gas detectors and L-band optical fiber communications. 展开更多
关键词 BROADBAND superluminescent diodes graded composition buried hetero-structure
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Improvement of thermal conductivities and simulation model for glass fabrics reinforced epoxy laminated composites via introducing hetero-structured BNN-30@BNNS fillers 被引量:11
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作者 Xuetao Shi Ruihan Zhang +3 位作者 Kunpeng Ruan Tengbo Ma Yongqiang Guo Junwei Gu 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2021年第23期239-249,共11页
Hetero-structured thermally conductive spherical boron nitride and boron nitride nanosheets(BNN-30@BNNS)fillers were prepared via electro static self-assembly method.And the corresponding thermally conductive&elec... Hetero-structured thermally conductive spherical boron nitride and boron nitride nanosheets(BNN-30@BNNS)fillers were prepared via electro static self-assembly method.And the corresponding thermally conductive&electrically insulating BNN-30@BNNS/Si-GFs/E-44 laminated composites were then fabricated via hot compression.BNN-30@BNNS-Ⅲ(fBNN-30/fBNNS,1/2,wt/wt)fillers presented the optimal synergistic improvement effects on the thermal conductivities of epoxy composites.When the mass fraction of BNN-30@BNNS-Ⅲwas 15 wt%,λvalue of the BNN-30@BNNS-Ⅲ/E-44 composites was up to0.61 W m^(-1)K^(-1),increased by 2.8 times compared with pure E-44(λ=0.22 W m^(-1)K^(-1)),also higher than that of the 15 wt%BNN-30/E-44(0.56 W m^(-1)K^(-1)),15 wt%BNNS/E-44(0.42 W m^(-1)K^(-1)),and 15 wt%(BNN-30/BNNS)/E-44(direct blending BNN-30/BNNS hybrid fillers,1/2,wt/wt,0.49 W m^(-1)K^(-1))composites.Theλin-plane(λ//)andλcross-plane(λ_(⊥))of 15 wt%BNN-30@BNNS-Ⅲ/Si-GFs/E-44 laminated composites significantly reached 2.75 W m^(-1)K^(-1)and 1.32 W m^(-1)K^(-1),186.5%and 187.0%higher than those of Si-GFs/E-44 laminated composites(λ//=0.96 W m^(-1)K^(-1)andλ_(⊥)=0.46 W m^(-1)K^(-1)).Established models can well simulate heat transfer efficiency in the BNN-30@BNNS-Ⅲ/Si-GFs/E-44 laminated composites.Under the condition of point heat source,the introduction of BNN-30@BNNS-Ⅲfillers were conducive to accelerating heat flow trans fe r.BNN-30@BNNS-Ⅲ/Si-GFs/E-44 laminated composites also demonstrated outstanding electrical insulating properties(cross-plane withstanding voltage,breakdown strength,surface&volume resistivity of 51.3 kV,23.8 kV mm^(-1),3.7×10^(14)Ω&3.4×10^(14)Ω·cm,favorable mechanical properties(flexural strength of 401.0 MPa and ILSS of 22.3 MPa),excellent dielectric properties(εof 4.92 and tanδof 0.008)and terrific thermal properties(T_(g )of 167.3℃and T_(HRI) of 199.2℃). 展开更多
关键词 Epoxy resins Thermally conductive laminated composites Glass fabrics hetero-structured fillers
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Si/Si C-based DD hetero-structure IMPATTs as MM-wave power-source:a generalized large-signal analysis 被引量:4
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作者 Moumita Mukherjee P.R.Tripathy S.P.Pati 《Journal of Semiconductors》 EI CAS CSCD 2015年第6期58-63,共6页
A full-scale, self-consistent, non-linear, large-signal model of double-drift hetero-structure IMPATT diode with general doping profile is derived. This newly developed model, for the first time, has been used to anal... A full-scale, self-consistent, non-linear, large-signal model of double-drift hetero-structure IMPATT diode with general doping profile is derived. This newly developed model, for the first time, has been used to analyze the large-signal characteristics of hexagonal SiC-based double-drift IMPATT diode. Considering the fabrication feasibility, the authors have studied the large-signal characteristics of Si/SiC-based hetero-structure devices. Under small-voltage modulation (~ 2%, i.e. small-signal conditions) results are in good agreement with calculations done using a linearised small-signal model. The large-signal values of the diode's negative conductance (5 × 106 S/m2), susceptance (10.4 × 107 S/m2), average breakdown voltage (207.6 V), and power generating efficiency (15%, RF power: 25.0 W at 94 GHz) are obtained as a function of oscillation amplitude (50% of DC breakdown voltage) for a fixed average current density. The large-signal calculations exhibit power and efficiency saturation for large-signal (〉 50%) voltage modulation and thereafter decrease gradually with further increasing voltage-modulation. This generalized large-signal formulation is applicable for all types of IMPATT structures with distributed and narrow avalanche zones. The simulator is made more realistic by incorporating the space-charge effects, realistic field and temperature dependent material parameters in Si and SiC. The electric field snap-shots and the large-signal impedance and admittance of the diode with current excitation are expressed in closed loop form. This study will act as a guide for researchers to fabricate a high-power Si/SiC-based IMPATT for possible application in high-power MM-wave communication systems. 展开更多
关键词 Si/SiC hetero-structure double drift diode full-scale large-signal modelling high-power parasiticeffects noise-analysis
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Atypical BiOCl/Bi_2S_3 hetero-structures exhibiting remarkable photo-catalyst response 被引量:5
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作者 Muhammad Tanveer 吴宇 +1 位作者 Muhammad Abdul Qadeer 曹传宝 《Science China Materials》 SCIE EI CSCD 2018年第1期101-111,共11页
We demonstrate the fabrication of BiOCl/Bi_2S_3 which is well defined at a large scale. The BiOCl/Bi_2S_3 heterostructures exhibit an enhanced photo-catalytic degradation of methyl orange(MO) compared to BiOCl and B... We demonstrate the fabrication of BiOCl/Bi_2S_3 which is well defined at a large scale. The BiOCl/Bi_2S_3 heterostructures exhibit an enhanced photo-catalytic degradation of methyl orange(MO) compared to BiOCl and Bi_2S_3, attributed to the interface between Bi_2S_3 and BiOCl, which effectively separate the photo-induced electron-hole pairs and suppress their recombination. 展开更多
关键词 bismuth sulfide hetero-structures photo-catalyst response
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2D hetero-structures based on transition metal dichalcogenides:fabrication,properties and applications 被引量:5
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作者 Ping Liu Bin Xiang 《Science Bulletin》 SCIE EI CAS CSCD 2017年第16期1148-1161,共14页
Recently,two dimensional transition metal dichalcogenides MX_2(M = Mo,W,etc; X = S,Se,Te) have ignited immense interests because of their unique structural and physical properties for the potential applications in the... Recently,two dimensional transition metal dichalcogenides MX_2(M = Mo,W,etc; X = S,Se,Te) have ignited immense interests because of their unique structural and physical properties for the potential applications in the nano-optoelectronics,valley-spintronics etc. In terms of the structural compatibility and van der Waals interaction,two dimensional(2D) MX_2 layers can be fabricated into various lateral and vertical hetero-structures. The atomically-thin hetero-structures comprising different layered MX_2 provide a new platform for exploring fundamental physics and device technologies with unprecedented phenomenon and extraordinary functionalities. In this review,we report the recent progress about the fabrication,properties and applications of 2D hetero-structures based on transition metal dichalcogenides. 展开更多
关键词 Transition metal dichalcogenides hetero-structures Chemical vapor deposition Charge transfer Optoelectronic devices
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Broadband diffuse optical spectroscopy of two-layered scattering media containing oxyhemoglobin,deoxyhemoglobin,water,and lipids 被引量:1
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作者 Giles Blaney Martina Bottoni +2 位作者 Angelo Sassaroli Cristianne Fernandez Sergio Fantini 《Journal of Innovative Optical Health Sciences》 SCIE EI CAS 2022年第3期92-106,共15页
We investigated the relationship between chromophore concentrations in two-layered scattering media and the apparent chromophore concentrations measured with broadband optical spectroscopy in conjunction with commonly... We investigated the relationship between chromophore concentrations in two-layered scattering media and the apparent chromophore concentrations measured with broadband optical spectroscopy in conjunction with commonly used homogeneous medium inverse models.We used diffusion theory to generate optical data from a two-layered distribution of relevant tissue absorbers,namely,oxyhemoglobin,deoxyhemoglobin,water,and lipids,with a top-layer thickness in the range 1–15 mm.The generated data consisted of broadband continuous-wave(CW)diffuse reflectance in the wavelength range 650–1024 nm,and frequency-domain(FD)diffuse reflectance at 690 and 830 nm;two source-detector distances of 25 and 35mm were used to simulate a dual-slope technique.The data were inverted using diffusion theory for a semi-infinite homogeneous medium to generate reduced scattering coeffcients at 690 and 830nm(from FD data)and effective absorption spectra in the range 650–1024nm(from CW data).The absorption spectra were then converted into effective total concentration and oxygen saturation of hemoglobin,as well as water and lipid concentrations.For absolute values,it was found that the effective hemoglobin parameters are typically representative of the bottom layer,whereas water and lipid represent some average of the respective concentrations in the two layers.For concentration changes,lipid showed a significant cross-talk with other absorber concentrations,thus indicating that lipid dynamics obtained in these conditions may not be reliable.These systematic simulations of broadband spectroscopy of two-layered media provide guidance on how to interpret effective optical properties measured with similar instrumental setups under the assumption of medium homogeneity. 展开更多
关键词 Broadband spectroscopy two-layer medium heterogeneous forward model homo-geneous inverse model partial-volume effect
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Hetero-structured ZnIn_(2)S_(4)-NiO@MOF photo-catalysts for efficient hydrogen evolution 被引量:1
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作者 Hongyu Ma Yong Liu +1 位作者 Rui Xiong Jianhong Wei 《Chinese Chemical Letters》 SCIE CAS CSCD 2022年第2期1042-1046,共5页
To obtain a high-performance heterogeneous photo-catalyst, herein, the hetero-structured Zn In_(2)S_(4)-Ni O@MOF(ZNM) nano-sheets are designed and prepared by partial pyrolysis of nickel-based MOFs(NiMOF) combined wit... To obtain a high-performance heterogeneous photo-catalyst, herein, the hetero-structured Zn In_(2)S_(4)-Ni O@MOF(ZNM) nano-sheets are designed and prepared by partial pyrolysis of nickel-based MOFs(NiMOF) combined with the low-temperature solvo-thermal method. The results indicate that the NiO nanoparticles, produced by partial pyrolysis of the Ni-MOF, have a high density of the surface active sites with limited aggregation, which act as a co-catalyst to capture photo-induced charge carriers. In addition, the morphology and structure of Ni-MOF nano-sheets were preserved in ZNM, which is beneficial to the reduction of the conduction barrier for the photo generated electron-hole pairs. With the synergetic advantages of co-catalyst and unique two-dimensional hetero-structure, ZNM nano-sheets exhibited significantly improved activity for photo-catalytic hydrogen production. 展开更多
关键词 Metal-organic frameworks ZnIn_(2)S_(4)-NiO@MOF hetero-structured Photo-catalyst Hydrogen production
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Improvement in mechanical properties of hypereutectic Al-Si-Cu alloys through sonosolidified slurry 被引量:1
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作者 Yoshiki Tsunekawa Shinpei Suetsugu +2 位作者 Masahiro Okumiya Naoki Nishikawa Yoshikazu Genma 《China Foundry》 SCIE CAS 2014年第4期396-401,共6页
For the wider applications,it is necessary to improve the ductility as well as the strength and wear-resistance of hypereutectic AlSi-Cu alloys,which are typical light-weight wear-resistant materials.An increase in th... For the wider applications,it is necessary to improve the ductility as well as the strength and wear-resistance of hypereutectic AlSi-Cu alloys,which are typical light-weight wear-resistant materials.An increase in the amounts of primary silicon particles causes the modified wear-resistance of hypereutectic Al-Si-Cu alloys,but leads to the poor strength and ductility.It is known that dual phase steels composed of hetero-structure have succeeded in bringing contradictory mechanical properties of high strength and ductility concurrently.In order to apply the idea of hetero-structure to hypereutectic Al-Si-Cu alloys for the achievement of high strength and ductility along with wear resistance,ultrasonic irradiation of the molten metal during the solidification,which is called sono-solidification,was carried out from its molten state to just above the eutectic temperature.The sono-solidified Al-17Si-4Cu alloy is composed of hetero-structure,which are,hard primary silicon particles,soft non-equilibrium a-Al phase and the eutectic region.Rheo-casting was performed at just above the eutectic temperature with sono-solidified slurry to shape a disk specimen.After the rheo-casting with modified sonosolidified slurry held for 45 s at 570 oC,the quantitative optical microscope observation exhibits that the microstructure is composed of 18area%of hard primary silicon particles and 57area%of soft a-Al phase.In contrast,there exist only 5 area%of primary silicon particles and no a-Al phase in rheo-cast specimen with normally solidified slurry.Hence the tensile tests of T6 treated rheo-cast specimens with modified sono-solidified slurry exhibit improved strength and 5%of elongation,regardless of having more than 3 times higher amounts of primary silicon particles compared to that of rheo-cast specimen with normally solidified slurry. 展开更多
关键词 semisolid casting slurry ultrasonic vibration sonosolidification hetero-structure hypereutectic aluminum alloy primary silicon a-Al solid solution
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BOUNDS FOR COMMUTATORS OF MULTILINEAR FRACTIONAL INTEGRAL OPERATORS WITH HOMOGENEOUS KERNELS
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作者 Jinhui Wang Jing Lan Jun Li 《Analysis in Theory and Applications》 2011年第2期181-186,共6页
We will show bounds for commutators of multilinear fractional integral operators with some homogeneous kernels.
关键词 multilinear operator fractional integral COMMUTATOR multiple weight homo-geneous kernel
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Electronic Structure of Single-Crystal CaF<sub>2</sub>(111) with Nanoscale Phases of Ca and Si
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作者 Yokub Suvonovich Ergahov Boltakhodja Ermatovich Umirzakov Gulmira Khalmuratovna Allayarova 《Materials Sciences and Applications》 2018年第12期965-971,共7页
The impact of Ca and Si nano-scale structures on parameters and density of states of single-crystalline CaF2(111) was studied. It was shown that at low concentration of ions of Ar+ (D ≤ 5 × 1015 cm-2) one witnes... The impact of Ca and Si nano-scale structures on parameters and density of states of single-crystalline CaF2(111) was studied. It was shown that at low concentration of ions of Ar+ (D ≤ 5 × 1015 cm-2) one witnesses formation of nanoscale phases on CaF2 surface. It was revealed that these phases lead to narrowing of the forbidden band Еg between the phases by 4 - 4.5 eV. At higher concentrations (D ≈ 6 × 1016 cm-2) the surface completely is covered by Ca atoms. It was shown that deposition of θ = 10 thick Si single layer on CaF2 surface manifests island picture. The concentration of Ca and Si nano-scale phases on the surface of CaF2 and the band gap of the phases were investigated as a function of (hν) of passing light. Nano-scale phases and nano-scale films of Ca were obtained by using the technique of bombardment with ions of Ar+ of CaF2 surface. Formation of nano-scale phases were accompanied by change in the composition and structure of CaF2 zones located between the phases. These changes led to narrowing of the forbidden band of CaF2 down to 7.5 - 8 eV. The concentration of Ca and Si nano-scale phases on the surface of CaF2 and the band gap of the phases were investigated as a function of (hν) of passing light. 展开更多
关键词 NANO-SCALE Band Gap hetero-structures Surface BOMBARDMENT
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Highly Thermally Conductive Polydimethylsiloxane Composites with Controllable 3D GO@f-CNTs Networks via Self-sacrificing Template Method 被引量:2
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作者 Shuang-Shuang Wang Dian-Ying Feng +4 位作者 Zhi-Ming Zhang Xia Liu Kun-Peng Ruan Yong-Qiang Guo Jun-Wei Gu 《Chinese Journal of Polymer Science》 SCIE EI CAS CSCD 2024年第7期897-906,I0005,共11页
Constructing controllable thermal conduction networks is the key to efficiently improve thermal conductivities of polymer composites.In this work,graphite oxide(GO)and functionalized carbon nanotubes(f-CNTs)are combin... Constructing controllable thermal conduction networks is the key to efficiently improve thermal conductivities of polymer composites.In this work,graphite oxide(GO)and functionalized carbon nanotubes(f-CNTs)are combined to prepare“Line-Plane”-like hetero-structured thermally conductive GO@f-CNTs fillers,which are then performed to construct controllable 3D GO@f-CNTs thermal conduction networks via selfsacrificing template method based on oxalic acid.Subsequently,thermally conductive GO@f-CNTs/polydimethylsiloxane(PDMS)composites are fabricated via casting method.When the size of oxalic acid is 0.24 mm and the volume fraction of GO@f-CNTs is 60 vol%,GO@f-CNTs/PDMS composites present the optimal thermal conductivity coefficient(λ,4.00 W·m^(-1)·K^(-1)),about 20 times that of theλof neat PDMS(0.20 W·m^(-1)·K^(-1)),also much higher than theλ(2.44 W·m^(-1)·K^(-1))of GO/f-CNTs/PDMS composites with the same amount of randomly dispersed fillers.Meanwhile,the obtained GO@f-CNTs/PDMS composites have excellent thermal stability,whoseλdeviation is only about 3%after 500 thermal cycles(20-200℃). 展开更多
关键词 POLYDIMETHYLSILOXANE hetero-structured thermally conductive fillers Self-sacrificing template Thermal conduction networks
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High‑Performance Stretchable Supercapacitors Based on Centrifugal Electrospinning‑Directed Hetero‑structured Graphene–Polyaniline Hierarchical Fabric 被引量:1
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作者 Yun Zheng Zengming Man +3 位作者 Yang Zhang Guan Wu Wangyang Lu Wenxing Chen 《Advanced Fiber Materials》 SCIE EI CAS 2023年第5期1759-1772,共14页
Stretchable supercapacitors(S-SCs)are of considerable interest as prospective energy-storage devices for wearable electronics and smart products.However,achieving high energy density and stable output under large defo... Stretchable supercapacitors(S-SCs)are of considerable interest as prospective energy-storage devices for wearable electronics and smart products.However,achieving high energy density and stable output under large deformations remains an urgent challenge.Here,we develop a high-performance S-SC based on a robust heterostructured graphene–polyaniline(G-PANI)anchored hierarchical fabric(G-PANI@pcPU).By precisely manipulating centrifugal electrospinning and PANI-induced two-step self-assembly process,the G-PANI@pcPU features an inter-linkage porous backbone,which open ions migration/intercalation pathways,high mechanical flexibility(elongation:400%),and large production area(>90 cm^(2)).The resultant G-PANI@pcPU presents ultra-large specific areal capacitance(Careal)of 5093.7 mF cm^(-2)(about 35 mg cm^(-2)mass loading of G-PANI)and redox reversibility in 1 M H_(2)SO_(4) electrolyte.Additionally,the G-PANI@pcPU fabric-based solid-state S-SCs show a high energy density of 69.2μWh cm^(-2)and capacitance of 3113.7 mF cm^(-2).More importantly,the superior stretchable stability(84.1%capacitance retentions after 5000 cycles)and foldable performance(86.7%capacitance retentions after 5000 cycles)of S-SCs are impressively achieved.Finally,the S-SCs realize potential applications of steady powering light-emitting diode(LED)lights at 100%strain,smart watch at bending deformation,toy car,and lamp.This work can offer an overwhelming foundation for designing advanced flexible electrodes toward new energy and smart wearable applications. 展开更多
关键词 Stretchable supercapacitor Hierarchical fabric Deformable stability hetero-structured graphene-polyaniline Wearable application
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Ta_(3)N_(5)/CdS Core–Shell S‑scheme Heterojunction Nanofibers for Efficient Photocatalytic Removal of Antibiotic Tetracycline and Cr(VI):Performance and Mechanism Insights 被引量:5
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作者 Shijie Li Mingjie Cai +1 位作者 Chunchun Wang Yanping Liu 《Advanced Fiber Materials》 SCIE EI 2023年第3期994-1007,共14页
Ta_(3)N_(5)/CdS core–shell S-scheme heterojunction nanofibers are fabricated by in situ growing CdS nanodots on Ta_(3)N_(5) nanofib-ers via a simple wet-chemical method.These Ta_(3)N_(5)/CdS nanofibers not only affor... Ta_(3)N_(5)/CdS core–shell S-scheme heterojunction nanofibers are fabricated by in situ growing CdS nanodots on Ta_(3)N_(5) nanofib-ers via a simple wet-chemical method.These Ta_(3)N_(5)/CdS nanofibers not only affords superior photocatalytic tetracycline degradation and mineralization performance,but also cause an efficient photocatalytic Cr(VI)reduction performance.The creation of favorable core–shell fiber-shaped S-scheme hetero-structure with tightly contacted interface and the maximum interface contact area promises the effective photo-carrier disintegration and the optimal photo-redox capacity synchronously,thus leading to the preeminent photo-redox ability.Some critical environmental factors on the photo-behavior of Ta_(3)N_(5)/CdS are also evaluated in view of the complexity of the authentic aquatic environment.The degradation products of tetracycline were confirmed by HPLC–MS analyses.Furthermore,the effective decline in eco-toxicity of TC intermediates is confirmed by QSAR calculation.This work provides cutting-edge guidelines for the design of high-performance Ta_(3)N_(5)-based S-scheme heterojunction nanofibers for environment restoration. 展开更多
关键词 Ta_(3)N_(5)/CdS Electrospinning S-scheme heterojunction Core–shell hetero-structure Cr(VI)reduction Antibiotic degradation
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