Grasping the underlying mechanisms behind the low lattice thermal conductivity of materials is essential for the efficient design and development of high-performance thermoelectric materials and thermal barrier coatin...
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Grasping the underlying mechanisms behind the low lattice thermal conductivity of materials is essential for the efficient design and development of high-performance thermoelectric materials and thermal barrier coating *** this paper,we present a first-principles calculations of the phonon transport properties of Janus Pb_(2)PAs and Pb_(2)SbAs *** materials possess low lattice thermal conductivity,at least two orders of magnitude lower than graphene and *** room temperature thermal conductivity of Pb_(2)SbAs(0.91 W/m K)is only a quarter of that of Pb_(2)PAs(3.88 W/m K).We analyze in depth the bonding,lattice dynamics,and phonon mode level information of these ***,it is determined that the synergistic effect of low group velocity due to weak bonding and strong phonon anharmonicity is the fundamental cause of the intrinsic low thermal conductivity in these Janus *** regular residual analysis further indicates that the four-phonon processes are limited in Pb_(2)PAs and Pb_(2)SbAs,and the three-phonon scattering is sufficient to describe their *** this study,the thermal transport properties of Janus Pb_(2)PAs and Pb_(2)SbAs monolayers are illuminated based on fundamental physical mechanisms,and the low lattice thermal conductivity endows them with the potential applications in the field of thermal barriers and thermoelectrics.
Designing new materials and architectures to maintain activity and stability requires a better understanding on the anticorrosion dynamics of ***-coordinated atoms on the surface of nanoparticles can be protected by d...
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Designing new materials and architectures to maintain activity and stability requires a better understanding on the anticorrosion dynamics of ***-coordinated atoms on the surface of nanoparticles can be protected by deposited ***-time observation on how protective shells grow and play a role is challenging but ***,protective effects of AuCl_(3) shells on Au nanobipyramids(NBPs)are studied in HAuCl_(4) aqueous solutions by in-situ liquid cell transmission electron microscopy(LCTEM).This study is the first to observe the formation of Au-AuCl_(3) core-shell nanostructure and the corresponding anticorrosion behaviors of AuCl_(3) deposited *** presence of CTAB can substantially influence the growth mode and structure of AuCl_(3) shell,by a direct or indirect way,intervene the dissolution of Au *** growth or dissolution kinetics here revealed at the nanoscale provide insights towards engineering of the surface anticorrosion to pursue Au nanoparticles with improved stability in acidic environment.
Two-dimensional(2D)van der Waals magnetic materials have promising and versatile electronic and magnetic properties in the 2D limit,indicating a considerable potential to advance spintronic *** predictions thus far ha...
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Two-dimensional(2D)van der Waals magnetic materials have promising and versatile electronic and magnetic properties in the 2D limit,indicating a considerable potential to advance spintronic *** predictions thus far have not ascertained whether monolayer VCl_(3) is a ferromagnetic(FM)or anti-FM monolayer;this also remains to be experimentally *** theoretically investigate the influence of potential factors,including C_(3) symmetry breaking,orbital ordering,epitaxial strain,and charge doping,on the magnetic ground *** first-principles calculations,we predict a collinear type-Ⅲ FM ground state in monolayer VCl_(3) with a broken C_(3) symmetry,wherein only the former two of three t_(2g)orbitals(a_(1g),e_(g2)^(π)and e_(g1)^(π))are *** atomic layer thickness and bond angles of monolayer VCl_(3) undergo abrupt changes driven by an orbital ordering switch,resulting in concomitant structural and magnetic phase *** doping to the underlying Cl atoms of monolayer VCl_(3) without C_(3) symmetry simultaneously induces in-and out-of-plane *** can achieve a multiferroic phase transition if combined with the discovered adjustments of magnetic ground state and polarization magnitude under *** establishment of an orbital-ordering driven regulatory mechanism can facilitate deeper exploration and comprehension of magnetic properties of strongly correlated systems in monolayer VCl_(3).
van der Waals heterostructures(vdWHs)based on two-dimensional(2D)materials without the crystal lattice matching constraint have great potential for high-performance optoelectronic ***,a WS_(2)/InSe vdWH photodiode is ...
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van der Waals heterostructures(vdWHs)based on two-dimensional(2D)materials without the crystal lattice matching constraint have great potential for high-performance optoelectronic ***,a WS_(2)/InSe vdWH photodiode is proposed and fabricated by precisely stacking InSe and WS_(2)flakes through an all-dry transfer *** WS_(2)/InSe vdWH forms an n–n heterojunction with strong built-in electric field due to their intrinsic n-type semiconductor characteristics and energy-band alignments with a large Fermi level offset between WS_(2)and *** a result,the device displays excellent photovoltaic behavior with a large open voltage of 0.47 V and a short-circuit current of 11.7 nA under 520 nm light ***,a fast rising/decay time of 63/76μs,a large light on/off ratio of 105,a responsivity of 61 mA/W,a high detectivity of 2.5×10^(11) Jones,and a broadband photoresponse ranging from ultraviolet to near-infrared(325–980 nm)are achieved at zero *** study provides a strategy for developing high-performance self-powered broadband photodetectors based on 2D materials.
Acquiring real-time spectral information in point-of-care diagnosis,internet-of-thing,and other lab-on-chip applications require spectrometers with hetero-integration capability and miniaturized *** to conventional se...
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Acquiring real-time spectral information in point-of-care diagnosis,internet-of-thing,and other lab-on-chip applications require spectrometers with hetero-integration capability and miniaturized *** to conventional semiconductors integrated by heteroepitaxy,solution-processable semiconductors provide a much-flexible integration platform due to their solution-processability,and,therefore,more suitable for the multi-material integrated ***,solution-processable semiconductors are usually incompatible with the micro-fabrication *** work proposes a facile and universal platform to fabricate integrated spectrometers with semiconductor substitutability by unprecedently involving the conjugated mode of the bound states in the continuum(conjugated-BIC)***,exploiting the conjugated-BIC photonics,which remains unexplored in conventional lasing studies,renders the broadband photodiodes with ultra-narrowband detection ability,detection wavelength tunability,and on-chip integration ability while ensuring the device *** based on these ultra-narrowband photodiode arrays exhibit high spectral resolution and wide/tunable spectral *** fabrication processes are compatible with solution-processable semiconductors photodiodes like perovskites and quantum dots,which can be potentially extended to conventional *** from the spectrometers directly constitute the incident spectra without being computation-intensive,latency-sensitive,and *** an example,the integrated spectrometers based on perovskite photodiodes are capable of realizing narrowband/broadband light reconstruction and in-situ hyperspectral imaging.
Bacterial cellulose(BC),a natural biomaterial synthesized by bacteria,has a unique structure of a cellulose nanofiberweaved three-dimensional reticulated *** films can be ultrasoft with sufficient mechanical strength...
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Bacterial cellulose(BC),a natural biomaterial synthesized by bacteria,has a unique structure of a cellulose nanofiberweaved three-dimensional reticulated *** films can be ultrasoft with sufficient mechanical strength,strong water absorption and moisture retention and have been widely used in facial *** films have the potential to be applied to implantable neural interfaces due to their conformality and moisture,which are two critical issues for traditional polymer or silicone *** this work,we propose a micro-electrocorticography(micro-ECoG)electrode named“Brainmask”,which comprises a BC film as the substrate and separated multichannel parylene-C microelectrodes bonded on the top *** can not only guarantee the precise position of microelectrode sites attached to any nonplanar epidural surface but also improve the long-lasting signal quality during acute implantation with an exposed cranial window for at least one hour,as well as the in vivo recording validated for one *** novel ultrasoft and moist device stands as a next-generation neural interface regardless of complex surface or time of duration.
With the increasing development of intelligent robots and wearable electronics,the demand for high-performance flexible energy storage devices is drastically *** this study,flexible symmetric microsupercapacitors(MSCs...
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With the increasing development of intelligent robots and wearable electronics,the demand for high-performance flexible energy storage devices is drastically *** this study,flexible symmetric microsupercapacitors(MSCs)that could operate in a wide working voltage window were developed by combining laser-direct-writing graphene(LG)electrodes with a phosphoric acid-nonionic surfactant liquid crystal(PA-NI LC)gel *** increase the flexibility and enhance the conformal ability of the MSC devices to anisotropic surfaces,after the interdigitated LG formed on the polyimide(PI)film surface,the devices were further transferred onto a flexible,stretchable and transparent polydimethylsiloxane(PDMS)substrate;this substrate displayed favorable flexibility and mechanical characteristics in the bending ***,the electrochemical performances of the symmetric MSCs with various electrode widths(300,400,500 and 600μm)were *** findings revealed that symmetric MSC devices could operate in a large voltage range(0–1.5 V);additionally,the device with a 300μm electrode width(MSC-300)exhibited the largest areal capacitance of 2.3 mF cm^(−2)at 0.07 mA cm^(−2)and an areal(volumetric)energy density of 0.72μWh cm−2(0.36 mWh cm^(−3))at 55.07μWcm−2(27.54mWcm−3),along with favorable mechanical and cycling *** charging for~20 s,two MSC-300 devices connected in series could supply energy to a calculator to operate for~130 s,showing its practical application potential as an energy storage ***,the device displayed favorable reversibility,stability and *** 12 months of aging in air at room temperature,its electrochemical performance was not altered,and after charging-discharging measurements for 5000 cycles at 0.07 mA cm^(−2),~93.6%of the areal capacitance was still retained;these results demonstrated its practical long-term application potential as an energy storage device.
Following the current rapid development of the Internet of Things(IoT)and wireless condition monitoring systems,energy harvesters which use ambient energy have become a key part of achieving an energy-autonomous *** w...
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Following the current rapid development of the Internet of Things(IoT)and wireless condition monitoring systems,energy harvesters which use ambient energy have become a key part of achieving an energy-autonomous *** wind energy harvesters have attracted widespread attention because of their great potential of power density as well as the rich availability of wind energy in many possible areas of *** article provides readers with a glimpse into the state-of-the-art of miniature wind energy *** crucial factors for them to achieve high working efficiency under lower operational wind speed excitation are *** potential energy coupling mechanisms are discussed in *** approaches for broadening operational wind-speed-range given a variety of energy coupling mechanisms are also presented,as observed in the *** enhancement mechanisms including hydrodynamic configuration optimization,and non-linear vibration pick-up structure are *** are drawn and the outlook for each coupling mechanisms is presented.
Osteochondral defect caused by trauma or osteoarthritis exhibits a major challenge in clinical treatment with limited symptomatic effects at *** regeneration and remodeling of subchondral bone play a positive effect o...
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Osteochondral defect caused by trauma or osteoarthritis exhibits a major challenge in clinical treatment with limited symptomatic effects at *** regeneration and remodeling of subchondral bone play a positive effect on cartilage regeneration and further promotes the repair of osteochondral *** use of the strengths of each preparation method,the combination of 3D printing and electrospinning is a promising method for designing and constructing multi-scale scaffolds that mimic the complexity and hierarchical structure of subchondral bone at the microscale and nanoscale,*** this study,the 3D printed-electrospun poly(ɛ-caprolactone)/nano-hydroxyapatites/multi-walled carbon nanotubes(PCL/nHA/MWCNTs)scaffolds were successfully constructed by the combination of electrospinning and layer-by-layer 3D *** resulting dual-scale scaffold consisted of a dense layer of disordered nanospun fibers and a porous microscale 3D scaffold layer to support and promote the ingrowth of subchondral ***,the biomimetic PCL/nHA/MWCNTs scaffolds enhanced cell seeding efficiency and allowed for higher cell-cell interactions that supported the adhesion,proliferation,activity,morphology and subsequently improved the osteogenic differentiation of bone marrow mesenchymal stem cells in ***,this study elucidates that the construction of 3D printed-electrospun PCL/nHA/MWCNTs scaffolds provides an alternative strategy for the regeneration of subchondral bone and lays a foundation for subsequent in vivo studies.
Maintaining low modulus while endowing the wide-range linear stretchability to wearable or implantable devices is crucial for these devices to reduce the mechanical mismatch between the devices and human skin/tissue *...
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Maintaining low modulus while endowing the wide-range linear stretchability to wearable or implantable devices is crucial for these devices to reduce the mechanical mismatch between the devices and human skin/tissue ***,improving linear stretchability often results in an increased modulus of stretchable electronic materials,which hinders their conformability in long-term quantifiable monitoring of ***,we develop a hybrid structure involving interlocking low-modulus porous elastomers(Ecoflex-0030)and MXene-based hydrogels with crosslinking networks of polyvinyl alcohol,sodium alginate,and *** hydrogel–elastomer structure exhibits superior performance compared with previous reports,with a wide linear stretchability strain range from 0 to 1000%and maintaining a low modulus of 6.4 ***,the hydrogel–elastomer hybrids can be utilized as highly sensitive strain sensors with remarkable characteristics,including high sensitivity(gauge factor~3.52),a linear correlation between the resistance and strain(0–200%),rapid response(0.18 s)and recovery times(0.21 s),and excellent electrical reproducibility(1000 loading–unloading cycles).Those electrical and mechanical properties allow the sensor to act as a suitable quantifiable equipment in organ monitoring,human activities detecting,and human–machine interactions.
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