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Considering a series of electromagnetic pollution problems brought by the development of electronic communication technology, more attention has been paid to the research of electromagnetic wave (EMW) absorbing materials with unique composition and structure. Herein, under the inspiration of mixed-dimensional hierarchical structure, 2D Ni2P nanosheets anchored on 1D silk-derived carbon fiber is successfully fabricated as a gratifying resistor-dielectric type absorber. By a controllable pyrolyzation strategy and disproportionated reaction, high-density 2D Ni2P nanosheets were grown vertically and cross-linked on the surface of 1D silk-derived carbon fiber. The sample exhibited superior EMW absorption performance with maximum reflection loss value of – 56.9 dB at the thickness of 2.32 mm and the effective absorption bandwidth can reach to 7.2 GHz at the thickness of 1.93 mm. In addition, the pure Ni2P shows remarkable dielectric characteristic and EMW absorption ability as well. The integration of dual-conductive loss, enhanced polarization relaxation loss and the multiple scattering in the composites was proved to contribute to the good EMW absorption performance. Therefore, this work confirms the great potentials of Ni2P as a high-efficient EMW absorbing materials and light a new way in construction of multidimensional absorber.

Recently, biomass-derived carbon absorbing materials have received extensive attention due to their diverse structures, wide sources and low cost. However, it is still a great challenge to construct high-efficiency biomass-based absorbers with hierarchical and multi-component micro-nanoarchitecture. To this end, a novel Co @ mesoporous C/macroporous C sheet hybrid was successfully prepared by in-situ self-assembly of ZnCo MOF nanosheet arrays on biomass-derived porous carbon sheets via hydrothermal and pyrolysis methods. By tuning the molar ratio of Zn2+ to Co2+ ions, the optimal RLmin value was up to −66.9 dB and a wide EAB of 5.6 GHz was simultaneously obtained at the filler loading of 12 wt%. The results showed that this unique 3D micro-nanostructure possessed larger specific surface area, rich heterogeneous interfaces, massive defects and multi-level porosity, which was favorable for multiple reflection and scattering, dielectric loss, magnetic loss, as well as impedance matching. As a consequence, the as-prepared composites displayed significantly enhanced microwave absorption performance than the pristine biomass carbon. In this regard, the integration of MOF monomer and biomass matrix is expected to provide new guidance for the design of hierarchical multi-scale porous heterostructures as lightweight and enhanced microwave absorbing materials.

We demonstrate 100-Gbaud on-off-keying (OOK) transmission driven at a low voltage using an electro-optic (EO) polymer modulator combined with a silicon Mach-Zehnder interferometer waveguide. Various types of organic- and polymer-based modulators have been reported to perform efficient EO modulation and high-speed data transmission at over 100 Gbaud. However, there are critical concerns regarding the practical application of polymer devices in terms of environmental stability. In particular, long-term thermal storage and stability during operation require improvements before EO polymer modulators can be applied in practical systems. We have developed an EO polymer with enhanced thermophysical stability and used it to fabricate an efficient EO polymer modulator. In this study we extend our earlier work on high-speed EO polymer modulators by performing fiber-link 100-Gbaud OOK transmission at various operating temperatures. A thermal stability test revealed that the EO polymer modulator can survive high-temperature exposure up to 110°C. Error-free signal transmissions over a distance of 2.0 km was successfully demonstrated with a driving voltage of 1.9 Vpp and a bit error rate below the 7% overhead forward error correction threshold. The driving voltage, bandwidth, bit error rate, and fiber-link performance of the device are presented.

At present, there are few studies on the development, evolution, and quantitative analysis of internal pores and cracks after heat treatment of coal. On the basis of this, low-temperature nitrogen ...

Developing high-efficiency electromagnetic wave absorption materials with versatility has been a hotspot and it remains a huge challenge. Here, we reported versatile laminated Ni nanoparticles @ porous carbon (Ni@C) nanocomposites synthesized by a facile carbonization of Ni-based metal-organic frameworks (MOFs) precursor. It was found that the phase components (Ni and C phases) and nano/microstructure (laminated and porous characterizations) were well-modified by controlling the calcination temperature, which led to the variation of the degree of graphitization, magnetic properties, and electromagnetic performances. It showed that the laminated porous Ni@C nanocomposites achieved enhanced microwave absorption performances with a thin thickness of 1.5 mm, a strong reflection loss of −59.8 dB and an effective absorption bandwidth of 4.5 GHz. The underlying microwave absorption mechanism was owing to the improved synergistic effects of polarization relaxation, electron transport, ferromagnetic resonance, as well as multiple reflections and scattering in the laminated porous Ni@C nanocomposites. Furthermore, the multicomponent and laminated porous architecture endowed nanocomposites with favorable waterproof, heat isolation and infrared shielding versatility. Therefore, this work demonstrated a facile approach to develop MOFs-derived versatile laminated porous nanocomposites with efficient microwave absorbing performances.

In PWR three-dimensional transient coupling calculation software CORCA-K, the nodal Green's function method and diagonal implicit Runge Kutta method are used to solve the spatiotemporal neutron dynamic diffusion equation, and the single-phase closed channel model and one-dimensional cylindrical heat conduction transient model are used to calculate the coolant temperature and fuel temperature. The LMW, NEACRP and PWR MOX/UO2 benchmarks and FangJiaShan (FJS) nuclear power plant (NPP) transient control rod move cases are used to verify the CORCA-K. The effects of burnup, fuel effective temperature and ejection rate on the control rod ejection process of PWR are analyzed. The conclusions are as follows: (1) core relative power and fuel Doppler temperature are in good agreement with the results of benchmark and ADPRES, and the deviation between with the reference results is within 3.0% in LMW and NEACRP benchmarks; 2) the variation trend of FJS NPP core transient parameters is consistent with the results of SMART and ADPRES. And the core relative power is in better agreement with the SMART when weighting coefficient is 0.7. Compared with SMART, the maximum deviation is −5.08% in the rod ejection condition and while −5.09% in the control rod complex movement condition.

PLLA- magnesium composites have been widely investigated as potential biodegradable materials for bone implants. Lower/higher corrosion resistance of the crystalized/amorphous magnesium alloys allows tailoring of biodegradability rate. In this work, the amorphous Mg65Zn30Ca5 was investigated versus traditional crystalized Mg65Zn30Ca5, and a PLLA-Mg65Zn30Ca5 composite has been successfully fabricated using hot injection process. Furthermore, the high corrosion resistance of the amorphous Mg65Zn30Ca5 prevented the high alkalization and deterioration of mechanical strength. In addition, the high Zn content intended to improve the glass forming ability, also enhances the anti-bacterial property of the PLLA-Mg65Zn30Ca5 composite. The remarkable performance of the PLLA-Mg65Zn30Ca5 composite shows its promising application in bone repair and tissue regeneration.

Metal-organic frameworks (MOFs) derived metal/carbon composites are considered as feasible high-performance electromagnetic wave absorption materials and have received considerable attention. Herein, biconical prisms Ni@C composites were fabricated via a simple carbonization of Ni-MOFs template. It was found that the core-shell biconical prisms Ni@C composites achieved an optimization of the impedance matching and an efficient microwave absorption performance by regulating the carbonization temperatures. As expected, the Ni@C composites obtained a stronger reflection loss of −52.9 dB at the matching thickness of 2.4 mm and covered an effective absorption bandwidth of 4.6 GHz with 2.0 mm thickness. The enhanced electromagnetic wave absorption performance resulted from the synergistic effect of the magnetic resonance, relaxation polarization, conductive loss, and multiple scatterings/reflections, which were generated by the nickel nanoparticles, carbon, CNT, the novel structure of core-shell Ni@C, and the carbon nanotubes wrapped biconical prisms Ni@C composites. In summary, our work introduced a facile paradigm for the development of MOFs-derived composites as enhanced electromagnetic wave absorption materials.

Background Polymer hydrogels have attracted considerable attention as functional materials. The conventional single network hydrogels (SNs) are mechanically either too soft or brittle to be used as load-bearing substances. Therefore, the interpenetrating network hydrogels (IPNs) with unique physical characteristics paid more and more attention and they have shown great potentials in fabricating a variety of food structures with desired functionalities. Scope and approach This review provided a summary of the latest developments and applications of IPNs in terms of synthesis strategies (heating-cooling, enzymatic, and ionic-induced technique), physical performance (mechanical property, water holding capacity, swelling capacity, and thermal property), formation and strengthening mechanisms, as well as food applications. The major future trends of IPNs in food systems were also discussed. Key findings and conclusions As compared with SNs, IPNs generally exhibited more favorable mechanical performance, water holding capacity and thermal stability. The strengthening mechanisms of IPNs were mainly attributed to the filling of polysaccharides in other biopolymers, the increased density of entangled network, and the possible interactions between individual networks. IPNs with tunable mechanical property could be fabricated, showing great potential for various food applications such as edible films, three-dimensional printing, delivery of bioactive/aroma compounds, as well as fat replacers.

At present, the development of lightweight and wideband microwave absorbing materials with stable infrared stealth property and adaptable to complex environments has become the key to multi-modal stealth technology. Herein, hollow CuS microflowers were self-assembled on biomass-derived porous carbon in situ to realize the multifunctions of microwave absorption, flame retardance and thermal stealth. The multicomponent synergistic effect combined with unique microarchitecture triggered the multiple polarization effects, multiple reflection and scattering as well as conduction loss in the PC@CuS composite. As a result, the PC800@CuS sample exhibited an optimal RLmin of −61.5 dB and an exceptionally wide EAB of 7.8 GHz with the filling ratio of only 10%. In addition, the PC@CuS composite also exhibited superior flame-retardant properties by virtue of its distinctive porous structure. Meanwhile, the uniform distribution of CuS particles played a vital role in enhancing the overall infrared absorption efficiency, thereby obtaining stable and highly-effective infrared stealth performance comparable to commercial products. This work shed light on the development of high-efficiency MAs with multifunctions in a facile and low-cost manner.

Metal halide perovskites have attracted great attention for their superior light energy conversion applications. Herein, we demonstrated a facile synthesis of zero-dimensional Sn2+ perovskite Cs4-xMxSnBr6(M = K+ and Rb+) material through the cation transformation reaction at room temperature. Cs4SnBr6 NCs was mixed with pure metal bromide salts (KBr and RbBr) via the mechanochemical process to successfully synthesize Cs4-xMxSnBr6 perovskite where transformation of Cs to mixed Cs/Rb and mixed Cs/K was achieved. By substituting different cations, the bright fluorescence of the Cs4-xMxSnBr6 was tuned from dim green to greenish-cyan while achieving the photoluminescence (PL) quantum yield of ∼39%. The crystal structure of Sn based perovskite with the substitution of K+ or Rb+ cations was determined by X-ray diffraction (XRD). Moreover, the Cs4-xMxSnBr6 demonstrated superior air stability and exhibited a better photocatalytic activity for CO2 reduction reaction (CO2RR) with high selectivity of CH4 gas with a higher yield rate compared to the pristine Cs4SnBr6 NCs.

The morphology modulation of multi-level structures and the multifunctional design of their composites are challenging research priorities in the field of electromagnetic wave absorption. In this work, the abandoned polyurethane is adopted as a sacrificial template of a three-dimensional carbon network. The morphology-controlled Fe/Fe2O3@porous carbon composites with highly cross-linked 3D structures are synthesized by simple hydrothermal and thermal treatments. Among them, the PM-700 with a coral-like structure has a minimum reflection loss of −54.7 dB at a thickness of 1.4 mm and an effective absorption bandwidth of 6.4 GHz (10.8–18 GHz) at 1.9 mm. The excellent absorption performance is attributed to the three-dimensional magnetic conductive network, which provides superior impedance matching, synergistic effects of dual-loss mechanisms, and multiple attenuation. Furthermore, benefiting from its unique three-dimensional structure, the PM-700 possesses low density (0.088 g/cm3), excellent mechanical properties (withstand more than 4000 times of its own weight), and high thermal management (thermal insulation and flame retardancy). Meanwhile, PM-700 exhibits excellent infrared stealth performance, which is conducive to the development of multi-band compatible stealth materials. This work not only contributes to the conservation of resources and reuse of wasted polyurethane, but also facilitates the multifunctional application of microwave absorbing materials with multi-level structures.

BiSe has emerged as a promising Te-free high-performance thermoelectric (TE) material base owing to its ultra-low lattice thermal conductivity caused by the Bi bilayers in its lattice. Herein, the TE properties of BiSe were modified by Sn doping and ball milling to improve its performance. The ball milling process reduced the grain size of the samples and affected their anisotropy during the pressing process, leading to the random arrangement of the (00 l ) plane, which improved the electrical conductivity of the samples in the direction parallel to the spark plasma sintering direction and increased the Seebeck coefficient. The increased defects and smaller grain size of the samples due to Sn doping and ball milling enhanced the scattering of phonon transport, thereby decreasing the lattice thermal conductivity. The improvement in the ZT of the samples was realized through the improvement in their thermal and electrical transport. The Spark plasma-sintered bulk of the ball-milled Bi0.9Sn0.1Se sample exhibited a high-power factor of 8.4 μW · cm−1 · K−2 at 473 K and an ultra-low lattice thermal conductivity of 0.43 W · m−1 · K−1 at 673 K along with the maximum ZT value of 0.32 at 473 K, which is 31.6% higher than that of the pristine BiSe sample.

Some living organisms such as the octopus have fantastic abilities to simultaneously swim away and alter body color/morphology for disguise and self-protection, especially when there is a threat perception. However, it is still quite challenging to construct artificial soft actuators with octopus-like synergistic shape/color change and directional locomotion behaviors, but such systems could enhance the functions of soft robotics dramatically. Herein, we proposed to utilize unique hydrophobic carbon dots (CDs) with rotatable surficial groups to construct the aggregation-induced emission (AIE) active glycol CDs polymer gel, which could be further employed to be interfacially bonded to an elastomer to produce anisotropic bilayer soft actuator. When putting the actuator on a water surface, glycol spontaneously diffused out from the gel layer to allow water intake, resulting in a color change from a blue dispersion fluorescence to red AIE and a shape deformation, as well as a large surface tension gradient that can promote its autonomous locomotion. Based on these findings, artificial soft swimming robots with octopus-like synergistic shape/color change and directional swimming motion were demonstrated. This study provides an elegant strategy to develop advanced multi-functional bio-inspired intelligent soft robotics.

Direct observation of oxygen evolution reaction (OER) on catalyst surface may significantly advance the mechanistic understanding of OER catalysis. Here, we report the first real-time nanoscale observation of chemical OER on Mn2O3 nanocatalyst surface using an in situ liquid holder in a transmission electron microscope (TEM). The oxygen evolution process can be directly visualized from the development of oxygen nanobubbles around nanocatalysts. The high spatial and temporal resolution further enables us to unravel the real-time formation of a surface layer on Mn2O3, whose thickness oscillation reflects a partially reversible surface restructuring relevant to OER catalysis. Ex situ atomic-resolution TEM on the residual surface layer after OER reveals its amorphous nature with reduced Mn valence and oxygen coordination. Besides shedding light on the dynamic OER catalysis, our results also demonstrate a powerful strategy combining in situ and ex situ TEM for investigating various chemical reaction mechanisms in liquid.

Computational study on relationship between molecular structure and property of small molecule hole-transporting materials (HTMs) is an efficient pathway to acquire potential HTMs for perovskite solar cells (PSCs). Herein, by conjugating the acceptor groups of electron-deficient diazatriphenylene (DAT), tetraazatriphenylene (TAT) and hexaazatriphenylene (HAT), and p-methoxy-substituted triphenylamine (MeOTPA) electron-donors, six novel donor–acceptor-donor (D-A-D) typed HTMs (SM11 ~ SM16) are designed. Furthermore, three thiophene-substituted acceptors (SM17 ~ SM19) are also investigated. The influences of acceptor moiety on the performance of HTMs are studied by carrying out theoretical chemical calculations. Compared with the reported HTM with triphenylene unit (TPH-T), the new tailored HTMs (SM11 ~ SM19) exhibit more negative highest occupied molecular orbital (HOMO) energy levels and slightly red-shifted light absorption due to the increased electron-deficient property of acceptor group and linked positions with the MeOTPA-donor. Meanwhile, our results show that the small torsion angle between the acceptor and the donor is beneficial to promote the hole transport in HTMs, and the thiophene units on acceptor may also be helpful to enhance the charge mobility of HTMs. In addition, the large charge transfer amounts and small exciton binding energies are found for designed HTMs, which will be favorable to facilitate the electron-hole separation in HTMs. The stability of HTMs may be decreased based on the calculated results of electrostatic surface potential and absolute hardness. We hope this work could highlight the potential of azatriphenylene acceptor-based D-A-D typed HTMs for efficient PSCs.

To explore the synergistic mechanism of polymer and surfactant in the binary combination flooding of low-permeability reservoirs, the adaptability experiment of polymer salt-resistant partially hydrolyzed polyacrylamide and nonionic surfactant was carried out in the indoor system. Experiments at different ratios are also performed. The results show that the selected poly/surface binary flooding system increases with the concentration of polymer or surfactant, the viscosity of the poly/surface binary system also increases and, at the same time, has better temperature and salt resistance. The viscosity of the binary system will decrease when the salinity increases. When the surfactant concentration CS = 0.2% and the polymer concentration CP = 0.2%, the viscosity of the system is the highest. The viscosity of the poly/table binary system at different concentrations decreases when the temperature rises: pure polymer (CP = 0.2%), poly/table binary system displacement fluid CP = 0.1% + CS = 0.2% and CP = 0.2% + CS = 0.2%; and the injection pressure first rises and then drops. The final recovery rate is 51.8%, which meets the development of most oil reservoirs.

Since the invention of transistors, the flow of electrons has become controllable in solid-state electronics. The flow of energy, however, remains elusive, and energy is readily dissipated to lattice via electron-phonon interactions. Hence, minimizing the energy dissipation has long been sought by eliminating phonon-emission process. Here, we report a different scenario for facilitating energy transmission at room temperature that electrons exert diffusive but quasiadiabatic transport, free from substantial energy loss. Direct nanothermometric mapping of electrons and lattice in current-carrying GaAs/AlGaAs devices exhibit remarkable discrepancies, indicating unexpected thermal isolation between the two subsystems. This surprising effect arises from the overpopulated hot longitudinal-optical (LO) phonons generated through frequent emission by hot electrons, which induce equally frequent LO-phonon reabsorption (“hot-phonon bottleneck”) cancelling the net energy loss. Our work sheds light on energy manipulation in nanoelectronics and power-electronics and provides important hints to energy-harvesting in optoelectronics (such as hot-carrier solar-cells)., Minimizing the energy dissipation is usually sought by eliminating phonon-emission process. Here, the authors find a different approach for facilitating energy transmission at room temperature that electrons exert diffusive but quasiadiabatic transport, free from substantial energy loss.

This paper deals with the free and forced, linear and nonlinear vibration of functionally graded (along with thickness) nanotube, considering the non-uniform cross-section that made a two-dimension...

As a dielectric loss-type absorber, lamellar transitional metal chalcogenides (LTMCs) become more and more popular in the electromagnetic (EM) absorbing field due to their unique two-dimensional sheet structure. However, it remains challenging for metallic sulfides to obtain magnetic loss, further promoting loss mechanism. Herein, magnetic Fe3S4 LTMCs micro-flowers@ wax gourd aerogel-derived carbon composites are fabricated through a facile pyrolysis process and subsequent hydrothermal method. Compared to a pure biomass carbon or Fe3S4, Fe3S4@C composites exhibited an optimized and adjustable EM characteristic, which can be put down to the synergistic effects between the dielectric/magnetic loss and the impedance match. The sample shows superior EM absorption properties with a minimum reflection loss (RL) of −58.85 dB at 3.1 mm and a broad effective bandwidth (EBW) of 5.40 GHz at the matching thickness of 2.0 mm with a filling ratio of 20 wt%. In addition, the radar cross section (RCS) simulation confirms that the material can effectively suppress EMW (−8.51 dB m2 at zero degree) in practical applications. Therefore, it is believed that the as-prepared Fe3S4@C hybrids can be one of the prospective candidates as high-efficiency EMW absorbers.

Large‐scale production of two‐dimensional (2D) materials still is a crucial point toward its practical applications. Violet phosphorus (VP) with a wide bandgap accelerates and broadens the potential applications of elemental phosphorus in optoelectronics. Here, we demonstrate the scalable production of solution‐processable violet phosphorus flakes stably dispersed in several solvents. The exfoliated VP flakes exhibit thickness‐dependent visible photoluminescence characteristics, which covers the shortcoming of black phosphorus. Meanwhile, the VP‐based field‐effect transistor reveals relatively competitive electrical properties to other liquid‐phase exfoliated 2D materials. Our study paves the way for a wide range of applications of optical devices, energy storage, catalysis, and sodium batteries based on large‐scale VP flakes.

In order to obtain a high accuracy with high machining efficiency for finishing hard alloy metal material, we proposed a hybrid finishing method which is electrochemical (ECM) effects assisted magnetic abrasive finishing (MAF). In this study, the electrochemical magnetic abrasive finishing (EMAF process) was divided into EMAF stage and MAF stage. The metal surface can be easily finished with the passive films formed in electrochemical reactions. Simultaneously, the passive films can be removed by frictional action between magnetic brush and workpiece surface. Thus, the essence of EMAF process is to form and remove the passive films on the workpiece surface. This study focused on investigating the finishing mechanism and finishing characteristics of EMAF process. Compared with traditional MAF process, it can be confirmed that the finishing efficiency is remarkably improved more than 75% by EMAF process, and the surface roughness is also lower in EMAF process. The optimal experimental result of EMAF process showed that the surface roughness was reduced to less than 30 nm from the original surface roughness 178 nm after 4 min in EMAF stage, and the surface roughness was finally reduced to 20 nm after 10 min in MAF stage. The material removal rate in hybrid finishing stage was nearly 7 times than that in MAF stage. Additionally, the effective finishing area in EMAF process was about 70% of that in MAF process.

A novel vacuum cooling system, which mainly consists of a 49-stage thermal transpiration based vacuum pump and a 100 L vacuum vessel, is proposed. The novel system can directly be driven by heat, w...

Once fires occur in a coalfield, large quantities of coal in the coalfield will be baked at high temperatures. The changes and differences in the microscopic and spontaneous combustion properties o...

Recently, it is in urgent need of exploring high-performance microwave absorbers to address the electromagnetic pollution. To this end, low dimensional materials have received the great attention due to their unique microstructures and properties. Constructing heterostructure materials by stacking 0D, 1D and 2D materials can combine the merits of the individual blocks while weakening their shortcomings. Herein, a novel 1D heterostructure hybrid was successfully synthesized through anchoring the flower-like 2D MoS2@Fe3O4 0D nanospheres on the surface of the 1D hollow carbon microtubes (CT) derived from cattail by electrostatic self-assembly. Notably, the minimum reflection loss (RLmin) and an effective absorption bandwidth (EAB) of the composite can reach −62 dB at 2.09 mm and 6.8 GHz at 2.35 mm, respectively, with a filling ratio of only 8%. It reveals that the rational combination of magnetic and dielectric materials with different dimensions can effectively tune the impedance matching and attenuation constant, leading to the superior microwave absorption performance. Furthermore, the unique microstructure of MoS2@Fe3O4/CT endows it with good hydrophobicity, highly desired for self-cleaning purposes. This work highlights that the 1D heterostructure MoS2@ Fe3O4@CT composites can serve as a promising candidate for the high-performance microwave absorber with lightweight, wideband, strong reflection loss and hydrophobicity.

The active color-changing ability of many living species has inspired scientists to replicate the optical property into soft wet and tissue-like hydrogel materials. However, the color-changing processes of most reported examples are controlled by the traditional stimuli (e.g., pH, temperature, and ions), which may suffer from the residual chemical product accumulation, and have difficulty in achieving local control and integration into the commercial robots, especially when applied as biomimetic skins. Herein, inspired by the nervous (bioelectricity) control of skin color change in cephalopods, we present an electrically powered multicolor fluorescent hydrogel system with asymmetric configuration that couples thermoresponsive fluorescent hydrogel with stacked graphene assembly (SGA)-based conductive paper through luminous paint as the middle layer. Owing to the highly controllable electrical stimulus in terms of amplitude and duration, the Joule heat supplied by SGA film can be regulated locally and in real time, leading to precise and local emission color control at low voltage. It also avoids the addition of any chemicals. Furthermore, the electrically powered color-changing hydrogel system can be conveniently integrated into the commercial robots as biomimetic skins that help them achieve desirable camouflage, display, or alarming functions.

High-performance electromagnetic wave absorption and electromagnetic interference (EMI) shielding materials with multifunctional characters have attracted extensive scientific and technological interest, but they remain a huge challenge. Here, we reported an electrostatic assembly approach for fabricating 2D/1D/0D construction of Ti3C2Tx/carbon nanotubes/Co nanoparticles (Ti3C2Tx/CNTs/Co) nanocomposites with an excellent electromagnetic wave absorption, EMI shielding efficiency, flexibility, hydrophobicity, and photothermal conversion performance. As expected, a strong reflection loss of -85.8 dB and an ultrathin thickness of 1.4 mm were achieved. Meanwhile, the high EMI shielding efficiency reached 110.1 dB. The excellent electromagnetic wave absorption and shielding performances were originated from the charge carriers, electric/magnetic dipole polarization, interfacial polarization, natural resonance, and multiple internal reflections. Moreover, a thin layer of polydimethylsiloxane rendered the hydrophilic hierarchical Ti3C2Tx/CNTs/Co hydrophobic, which can prevent the degradation/oxidation of the MXene in high humidity condition. Interestingly, the Ti3C2Tx/CNTs/Co film exhibited a remarkable photothermal conversion performance with high thermal cycle stability and tenability. Thus, the multifunctional Ti3C2Tx/CNTs/Co nanocomposites possessing a unique blend of outstanding electromagnetic wave absorption and EMI shielding, light-driven heating performance, and flexible water-resistant features were highly promising for the next-generation intelligent electromagnetic attenuation system. Highlights The 2D/1D/0D Ti3C2Tx/carbon nanotubes/Co nanocomposite is successfully synthesized via an electrostatic assembly.Nanocomposites exhibit an excellent electromagnetic wave absorption and a remarkable electromagnetic interference shielding efficiency.The flexible, waterproof, and photothermal conversion performances are achieved. Supplementary Information The online version contains supplementary material available at 10.1007/s40820-021-00673-9.

This study explores a novel WNbMoTaV high-entropy thin film (HETF) in amorphous structure via pulsed laser deposition system. The formation of amorphous structure of this high-entropy alloy is ascribed to the high cooling rate during the deposition process. The HETF shows a smooth surface with a height fluctuation of less than 13 nm. This film has a high electrical resistivity of ~ 320.6 μΩ∙cm and a low corrosion current density of 0.088 μA/cm2. The corrosion resistance of the HETF at ambient temperature is superior to the conventional AISI 316L stainless steel. The high electrical resistivity and excellent corrosion resistance of the HETF are mainly attributed to its chemical disorder, cocktail effect and homogeneous amorphous structure. This experimental phenomenon not only provides a basis for the preparation of amorphous alloy films with low glass forming ability by pulsed laser deposition system, also promotes the potential application of WNbMoTaV HETF in the microelectronic components as resistivity sensors.

Developing a multifunctional theranostic nanoplatform is vital for dealing with challenging matters correlated with cancers. In this paper, we report an improved facile and relatively green fabrication of highly monodisperse CoFe2O4 nanoparticles with tunable size and morphology. Furthermore, a multifunctional cancer theranostic nanoplatform (CoFe2O4 nanoparticles@dopamine@DOX) was successfully developed for magnetic-responsive on-demand hyperthermia and chemotherapy synergistic theranostics. The proposed nanoplatform exhibits outstanding magneto-triggered hyperthermia efficiency, magnetic-responsive controlled drug delivery capability, enhanced MRI T2-weighted signal, and good biocompatibility. More importantly, the in vivo tumor-bearing mouse model experiments indicated that the CoFe2O4 nanoparticles@dopamine@DOX nanomedicine could realize the functions of magnetic-responsive on-demand hyperthermia and DOX release, which significantly promoted the inactive condition of cancer cells and resulted in obvious tumor regression without evident toxic side effects. According to its facile and green fabrication approach, magneto-triggered high hyperthermia efficiency, magnetic-responsive on-demand cancer therapy, and noninvasive imaging mode, this multifunctional nanoplatform holds great advantages over traditional monotherapy techniques and provides an alternative for the precise clinical treatment of cancer. A multifunctional cancer theranostic nanoplatform (CoFe2O4 nanoparticles@dopamine@DOX) was successfully developed for magnetic-responsive on-demand hyperthermia and chemotherapy synergistic theranostics.

Unipolar barrier structures are used to suppress dark current in photodetectors by blocking majority carriers. Designing unipolar barriers with conventional materials is challenging due to the strict requirements of lattice and band matching. Two-dimensional materials have self-passivated surfaces and tunable band structures, and can thus be used to design unipolar barriers in which lattice mismatch and interface defects are avoided. Here, we show that band-engineered van der Waals heterostructures can be used to build visible and mid-wavelength infrared unipolar barrier photodetectors. Our nBn unipolar barrier photodetectors, which are based on a tungsten disulfide/hexagonal boron nitride/palladium diselenide heterostructure, exhibit a low dark current of 15 pA, a photocurrent of 20 μA and a detectivity of 2.7 × 1012 cm Hz1/2 W−1. Our pBp unipolar barrier photodetectors, which are based on a black phosphorus/molybdenum disulfide/graphene heterostructure, exhibit a room-temperature detectivity of 2.3 × 1010 cm Hz1/2 W−1 in the mid-wavelength infrared region under blackbody radiation. The pBp devices also show a dichroic ratio of 4.9 under blackbody radiation, and a response time of 23 μs under 2 μm laser illumination. Band-engineered van der Waals heterostructures that block dark current without suppressing photocurrent can be used to build detectors with high room-temperature detectivity for visible light and blackbody infrared light.

We show a top-down synthesis approach to mass-produce phosphorene-graphene nanosheet composites with superior cycle stability and rate capability. Currently, using exfoliation to achieve two-dimensional (2D) materials is primarily limited to pure crystals. We discover that high-quality nanoscale 2D composite phosphorene-graphene sheets can be directly exfoliated from extremely low-cost bulk three-dimensional (3D) black phosphorus-graphite composites synthesized by mechanical milling while maintaining the chemical bonding and intimate electronic contact between 2D composite layers. The hybrid phosphorene-graphene material delivers high reversible capacities of 2030, 2003, and 1597 mAh/g at high current densities of 2, 4, and 6 A/g, respectively. Quantifying the dimensional electrochemical performance, we show that 2D phosphorene-graphene nanosheets not only have excellent electrochemical kinetics for fast lithium-ion diffusion and storage but also maintain the overall structural robustness of the entire electrode for long-term cyclability. This scalable synthesis paves the way for the practical application of phosphorene-graphene materials in batteries.

Two states of aluminum alloy material 7B04 T651 and 7B04 T74 using C-ring specimen were selected to carry out stress corrosion simulation test with different stress levels, corrosion concentrations and time, and the fracture morphology of the crack was observed and analyzed by optical microscope and scanning electron microscope (SEM). The results showed that 7B04-T74 alloy was insensitive to stress corrosion and was not prone to stress corrosion cracking under constant tensile stress lower than 432MPa; The stress corrosion cracking time of 7B04 T651 alloy under three different concentrations has no significant difference, and the stress corrosion cracking occurs within 7 days under the stress of 180MPa-432MPa. The time of stress corrosion cracking increased with the decrease of stress. Stress corrosion cracking (SCC) was very sensitive to Cl element, and it was also easy to produce SCC when the concentration of corrosive medium was low, the threshold value of corrosion cracking was about 108 MPa. SEM and EDS analysis showed that the fracture surface was intergranular, mud-like corrosion products, and secondary cracks. At the same time, the matrix grain boundaries were weakened by Cl element.

We present an O-band four-level pulse amplitude modulation (PAM4) transmitter based on a dual-drive silicon modulator with binary driving electronics at CMOS voltages, effectively eliminating the need for power-hungry digital-to-analog converters (DACs) and RF drivers. The fabricated dual-drive silicon modulator has cascaded p - n junction and p - i - n junction embedded in each arm of Mach-Zehnder interferometer, implementing high-speed data modulation and efficient bias control, respectively. Power dissipation of around 611 fJ/bit is obtained when synthesizing 46 Gb/s PAM4, showing high power efficiency. The fabricated silicon modulator exhibits a π-voltage-length product of 4.5 V·mm, and a 3-dB bandwidth of up to 27 GHz. Meanwhile, to implement a power-efficient PAM4 transceiver, the digital signal processing (DSP) at the receiver side is also discussed by balancing the performance and complexity. With a low-complexity DSP, negligible power penalty is observed after transmission over 38-km SSMF for both synthesized 20 Gb/s and 40 Gb/s PAM4. The presented PAM4 transmitter takes the advantages of both carrier-depletion and carrier-injection phase shifters for effective data modulation and bias control in PAM4 signalingand provides a power-efficient transmitter solution by eliminating the use of power-hungry DACs or RF drivers for datacenter interconnects.

A crack is found on the surface of stainless steel casting support. The crack was analyzed by macro and micro observation of fracture surface, Energy Dispersive Spectrometer (EDS) analysis, chemical analysis, microstructure examination and hardness test. Moreover, the stress distribution was simulated by finite element analysis. The results show that the crack model of the support is stress corrosion. The stress at the crack location is the largest. Three main factors of stress corrosion were the crack of paint layer, marine atmospheric environment and the pretightening force for the support. Because the service environment cannot be changed, therefore, surface paint protective effect and reduction of preload can be improved to avoid stress corrosion cracking again on the support.

The atomic diffusion in transition metal dichalcogenides (TMDs) van der Waals heterojunctions (HJs) strongly modifies their optoelectronic properties in the nanoscale. However, probing such localized properties challenges the spatial resolution and the sensitivity of a variety of analytic tools. Herein, a multimodal nanoscopy (based on tip enhanced Raman spectroscopy (TERS) and photoluminescence (TEPL)) combined with the Kelvin probe force microscopy (KPFM) method was used to probe such nanoscale localized optoelectronic properties induced by atomic diffusion. Chemical vapor deposition (CVD)-grown lateral bilayer (2L) WS2/MoS2 HJs were imaged with a spatial resolution better than 40 nm via TERS and TEPL mapping by using intrinsic Raman and photoluminescence (PL) peaks. The contact potential difference (CPD), capacitance, and PL variation in a nanoscale vicinity of the HJ interface can be correlated to the local stoichiometry variation determined by TERS. The diffusion coefficients of W and Mo were obtained to be ∼0.5 × 10-12 and ∼1 × 10-12 cm2/s, respectively, by using Fick's second law. The obtained results would be useful to further understand the localized optoelectronic response of the TMDs HJs.

Ferroelectric barium titanate nanoparticles (BTO NPs) may play critical roles in miniaturized passive electronic devices such as multi-layered ceramic capacitors. While increasing experimental and theoretical understandings on the structure of BTO and doped BTO have been developed over the past decade, the majority of the investigation was carried out in thin-film materials; therefore, the doping effect on nanoparticles remains unclear. Especially, doping-induced local composition and structure fluctuation across single nanoparticles have yet to be unveiled. In this work, we use electron microscopy-based techniques including high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), integrated differential phase contrast (iDPC)-STEM, and energy dispersive X-ray spectroscopy (EDX) mapping to reveal atomically resolved chemical and crystal structure of BTO and strontium doped BTO nanoparticles. Powder X-ray diffraction (PXRD) results indicate that the increasing strontium doping causes a structural transition from tetragonal to cubic phase, but the microscopic data validate substantial compositional and microstructural inhomogeneities in strontium doped BTO nanoparticles. Our work provides new insights into the structure of doped BTO NPs and will facilitate the materials design for next-generation high-density nano-dielectric devices.

In this work, the 3D worm-like expanded graphite (EG)/2D MoS2 nanosheets hybrids were synthesized by a facile in-situ self-assembled hydrothermal process. The 2D MoS2 nanosheets were uniformly and vertically grown on the surface of the 3D worm-like graphite, and interconnected with each other to form a hierarchical network structure. The unique honeycomb-like porous microstructure of the worm-like EG was conducive to the multiple scatterings and reflections, interconnected conductive network and improved impedance matching. In addition, the abundant heterogeneous interfaces in the MoS2/EG hybrids lead to enhanced dipole polarization and interfacial polarization. As a result, the MoS2/EG hybrids exhibited high-efficiency electromagnetic wave (EMW) absorption performance with an ultra-low filling ratio of 7 wt %. The MoS2/EG composites displayed an optimal reflection loss (RL) value of −52.3 dB at 15.1 GHz and a wide effective absorption bandwidth (EAB) of 4.1 GHz with a thickness of only 1.6 mm. The present work provides a significant guidance for the design and fabrication of the ultra-lightweight EMW absorbers with high performances.

In this study, we demonstrate the axiotaxy driven growth of belt-shaped InAs nanowires using Au catalysts by molecular beam epitaxy. It is found that, the zinc-blende structured InAs nanowires, with the features of [ $$\bar{1}\bar{1}\bar{3}$$ ] growth direction and extensive { $$1\bar{1}0$$ } side-surfaces, are induced by catalysts in Au-In α phase through the axiotaxy growth, in which the lattice mismatch between the projections of atomic planes onto nanowire/catalyst interfaces is minimized by forming extraordinary tilted interfaces. Our atomic-resolution in situ TEM heating experiments show that the catalysts remained in the solid state of Au-In α phase during the axiotaxy growth, by which the vapor—solid—solid growth mechanism can be confirmed. Through manipulating the growth direction, this unusual growth mechanism can provide a practical pathway to control the morphology of the low-dimensional nanomaterials, from conventional nanowires to belt-shaped nanowires utilizing a significant lateral growth, simply using nanoparticles as catalyst.

There is an emerging need for high-sensitivity solar-blind deep ultraviolet (DUV) photodetectors with an ultra-fast response speed. Although nanoscale devices based on Ga2O3 nanostructures have been developed, their practical applications are greatly limited by their slow response speed as well as low specific detectivity. Here, the successful fabrication of two-/three-dimensional (2D/3D) graphene (Gr)/PtSe2/β-Ga2O3 Schottky junction devices for high-sensitivity solar-blind DUV photodetectors is demonstrated. Benefitting from the high-quality 2D/3D Schottky junction, the vertically stacked structure, and the superior-quality transparent graphene electrode for effective carrier collection, the photodetector is highly sensitive to DUV light illumination and achieves a high responsivity of 76.2 mA/W, a large on/off current ratio of ~ 105, along with an ultra-high ultraviolet (UV)/visible rejection ratio of 1.8 × 104. More importantly, it has an ultra-fast response time of 12 µs and a remarkable specific detectivity of ~ 1013 Jones. Finally, an excellent DUV imaging capability has been identified based on the Gr/PtSe2/β-Ga2O3 Schottky junction photodetector, demonstrating its great potential application in DUV imaging systems.

Lithium-tellurium (Li-Te) batteries have attracted increasing attention as a next-generation energy storage system due to the appealing electrical conductivity and volumetric capacity. Porous carbon hosts are widely used for Te confinement to achieve good electrochemical performance in Li–Te batteries. However, there is a lack of understanding of the effect of carbon pore structure on the performance of Te/C cathodes. Herein, two types of carbons, one with micropores (ASAC25) and the other with mixed micropores and mesopores (ASAC30) are selected as Te hosts to clarify the role of carbon pore structure. Detailed investigations reveal that micropores, rather than mesopores, are critical for effective Te confinement due to complete infiltration of Te in micropores and enhanced Te and C interaction, thus enabling superior stability in ASAC25-Te. The dramatic capacity decline of ASAC30-Te is caused by the dissolution of bulky Te and the loss of active materials in long cycles. ASAC25-Te also achieved exceptional capacity retention of 83.3% after 500 cycles at 1C. Moreover, this work found that the ASAC25 carbon host should be partially filled with Te up to ∼60 wt% to accommodate volume change of Te. The clarification is expected to provide guidance on the further development of high-energy-density Te-based rechargeable batteries.

The Materials Imaging and Dynamics (MID) instrument at the European X-ray Free-Electron Laser facility is described. Recent commissioning results are discussed to illustrate the potential experimental applications of MID., The Materials Imaging and Dynamics (MID) instrument at the European X-ray Free-Electron Laser (EuXFEL) facility is described. EuXFEL is the first hard X-ray free-electron laser operating in the MHz repetition range which provides novel science opportunities. The aim of MID is to enable studies of nano-structured materials, liquids, and soft- and hard-condensed matter using the bright X-ray beams generated by EuXFEL. Particular emphasis is on studies of structure and dynamics in materials by coherent scattering and imaging using hard X-rays. Commission of MID started at the end of 2018 and first experiments were performed in 2019.

Suitable metal–support interaction is of great significance for the supported Fischer–Tropsch catalyst. Herein, we synthesized a series of porous spinel MAl2O4 (M = Co, Mg, Zn) together with Al2O3,...

In this study, we achieved a facile and low-cost (18-22 USD/g) synthesis of spiro[fluorene-9,9-phenanthren-10-one]-based interfacial layer materials (MSs; designated MS-PC, MS-PA, MS-OC, and MS-OA). Carbazoles and dimethylacridine substituents with an extended π-conjugation achieved through ortho- or para-orientations were used as donors at the spiro[fluorene-9,9'-phenanthren-10'-one] moiety. Highly efficient and stable inverted perovskite solar cells (PSCs) with the device architecture of ITO/NiOx/MSs/perovskite/PC61BM/BCP/Ag can be achieved to improve the surface morphology of NiOx when MSs are adopted as the interfacial layer. During a morphological study, the ortho-orientated donor of MS-OC and MS-OA has spherical structures indicated that the films were smooth and that the films of perovskite deposited on them had large grain size and uniformity. The photoluminescence properties of the perovskite layers on the NiOx/MSs were showed better hole-transporting capabilities than the bare NiOx. The dual-functional interfacial layer has shown defect passivation effect, it not only improved the surface morphology of NiOx but also enlarged the perovskite layer grain size. The best PSC device performance of the NiOx/MS-OC was characterized by 22.34 mA cm-2 short-circuit current density (Jsc), 1.128 V open-circuit voltage (Voc), and 80.8% fill factor (FF), resulting in 20.34% power conversion efficiency (PCE). The NiOx/MS-OC PSCs showed good long-term device stability, even retained the original PCE of 93.16% after 370 days under argon (25 °C). Owing to the superior perovskite morphologies of the NiOx/MSs, the resulting devices outperformed the bare NiOx-based PSCs.