Twisted transition metal dichalcogenides(TMDs) homo-bilayers host unique quantum properties,which can be tuned by interlayer twist angle θ.However,the systematic evolution of their typical electronic properties wit...
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Twisted transition metal dichalcogenides(TMDs) homo-bilayers host unique quantum properties,which can be tuned by interlayer twist angle θ.However,the systematic evolution of their typical electronic properties with respect to the twist angle θ,which is crucial for identifying the “special angle” analogous to the “magic angle” of twisted bilayer graphene in correlation physics studies,remains incompletely ***,via scanning tunneling microscopy(STM) and spectroscopy(STS),we investigate the variation of the moirépotential,flat band,and layer polarization characteristics across a wide range of twist angleθ in twisted bilayer MoS2(TB-MoS2).The moirépotential of the valence band exhibits a non-monotonic variation with θ,peaking at a maximum value up to 204 me Vat θ~1.7°.Concurrently,at the same θ,the bandwidth of the flat band at the ΓVpoint of the valence band attains its minimum,precisely signifying the “special angle” θc~1.7°in ***,layer polarization in the moirésuperlattice is spatially visualized through the distribution of local density of states(LDOS) at the energies of both ΓVand KVpoints of the valence band,where the polarization degree at the ΓVpoint demonstrates a close dependency on θ.Our findings deepen understanding of twist-angle effect in TMDs,advancing both fundamental physics and practical application.
The synthesis of polyurethanes(PUs) from the reaction of low molecular weight poly(ethylene carbonate)diol(PECD) is rarely investigated. This work reports a novel PU with excellent mechanical properties from the...
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The synthesis of polyurethanes(PUs) from the reaction of low molecular weight poly(ethylene carbonate)diol(PECD) is rarely investigated. This work reports a novel PU with excellent mechanical properties from the solution polymerization of 4,4-diphenylmethane diisocyanate(MDI) with PECD that was derived from the copolymerization of carbon dioxide(CO2) and ethylene oxide(EO). The tensile strength, the elongation at break and 300% constant tensile strength of the PECD-PU were up to 66 ± 2 MPa, 880%± 50% and 13 MPa, respectively, higher than the control PUs from the reaction of MDI with commercial polyethers or polyesters. The PECD-PU with high CO2carbonate content exhibited good solvent resistance and chemical stability. Of importance, the mechanical properties and chemical resistance of PECD-PU were significantly enhanced with the increasing content of CO2, i.e., the carbonate unit in PECD. This work provides comprehensive properties of PECD-derived PUs, indicating that PECD is a competitive precursor for the preparation of PU and has broad application prospects.
Heat stress hinders the growth and productivity of sweetpotato plants,predominantly through oxidative damage to cellular ***,the development of efficient approaches for mitigating heat-related impairments is essential...
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Heat stress hinders the growth and productivity of sweetpotato plants,predominantly through oxidative damage to cellular ***,the development of efficient approaches for mitigating heat-related impairments is essential for the long-term production of *** has been recognised for its capacity to assist plants in dealing with abiotic stress *** research aimed to investigate how different doses of exogenous melatonin influence heat damage in sweetpotato *** stress drastically affected shoot and root fresh weight by 31.8 and 44.5%,*** reduction resulted in oxidative stress characterised by increased formation of hydrogen peroxide(H_(2)O_(2))by 804.4%,superoxide ion(O_(2)^(·-))by 211.5%and malondialdehyde(MDA)by 234.2%.Heat stress also reduced chlorophyll concentration,photosystemⅡefficiency(F_v/F_m)by 15.3%and gaseous ***,pre-treatment with 100μmol L^(-1)melatonin increased growth and reduced oxidative damage to sweetpotato plants under heat *** particular,melatonin decreased H_(2)O_(2),O_(2)^(·-)and MDA by 64.8%,42.7%and 38.2%,*** also mitigated the decline in chlorophyll levels and improved stomatal traits,gaseous exchange and F_(v)/F_(m)(13%).Results suggested that the favorable outcomes of melatonin treatment can be associated with elevated antioxidant enzyme activity and an increase in non-enzymatic antioxidants and ***,these findings indicate that exogenous melatonin can improve heat stress tolerance in *** stu dy will assist re searchers in further investigating how melatonin makes sweetpotatoes more resistant to heat stress.
Layer-structured Ruddlesden–Popper(RP)perovskites(RPPs)with decent stability have captured the imagination of the photovoltaic research community and bring hope for boosting the development of perovskite solar cell(P...
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Layer-structured Ruddlesden–Popper(RP)perovskites(RPPs)with decent stability have captured the imagination of the photovoltaic research community and bring hope for boosting the development of perovskite solar cell(PSC)***,two-dimensional(2D)or quasi-2D RP PSCs are encountered with some challenges of the large exciton binding energy,blocked charge transport and poor film quality,which restrict their photovoltaic ***,these issues can be readily resolved by rationally designing spacer cations of *** review mainly focuses on how to design the molecular structures of organic spacers and aims to endow RPPs with outstanding photovoltaic *** firstly elucidated the important roles of organic spacers in impacting crystallization kinetics,charge transporting ability and stability of *** we brought three aspects to attention for designing organic ***,we presented the specific molecular structure design strategies for organic spacers of RPPs aiming to improve photovoltaic performance of RP *** proposed strategies in this review will provide new avenues to develop novel organic spacers for RPPs and advance the development of RPP photovoltaic technology for future applications.
Ethylene carbonate (EC) is the conventional and promising solvent to achieve high energy lithium metal ***,the innate low energy level of lowest unoccupied molecular orbital (LUMO) in EC makes it incompatible with...
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Ethylene carbonate (EC) is the conventional and promising solvent to achieve high energy lithium metal ***,the innate low energy level of lowest unoccupied molecular orbital (LUMO) in EC makes it incompatible with lithium metal,causing uncontrolled lithium growth and low Coulombic efficiency(CE).Herein,we introduced bis(2,2,2-trifluoroethyl) carbonate (TFEC),a carbonate with a strong electron-withdrawing effect (-CF3),which enhances the stability of EC at electrode interface by reducing ion-dipole interactions between Li+and *** the interaction between Li and EC weakens,TFEC and more PF6-anions coordinate with Li+,promoting the formation of contact ion pairs (CIPs) and aggregates (AGGs),thereby increasing the inorganic composition within the solid electrolyte ***,the distinct solvated sheath structure favors the decomposition of fluorinated solvents and PF6-anions,forming inorganic-rich electrode-electrolyte interfaces (SEI and CEI),thereby ensuring high stability for both the Li anode and high-voltage ***,when applied in the full-cell Li||LiMn0.8Fe0.2PO4,it displays consistent cycling performance,exhibiting minimal capacity decay with a retention rate of 62.5%after800 cycles,substantially surpassing that of cells using base electrolytes (29.8%).
Electrical energy is essential for modern society to sustain economic *** soaring demand for the electrical energy,together with an awareness of the environmental impact of fossil fuels,has been driving a shift toward...
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Electrical energy is essential for modern society to sustain economic *** soaring demand for the electrical energy,together with an awareness of the environmental impact of fossil fuels,has been driving a shift towards the utilization of solar ***,traditional solar energy solutions often require extensive spaces for a panel installation,limiting their practicality in a dense urban *** overcome the spatial constraint,researchers have developed transparent photovoltaics(TPV),enabling windows and facades in vehicles and buildings to generate electric *** TPV advancements are focused on improving both transparency and power output to rival commercially available silicon solar *** this review,we first briefly introduce wavelength-and non-wavelengthselective strategies to achieve *** of merit and theoretical limits of TPVs are discussed to comprehensively understand the status of current TPV *** we highlight recent progress in different types of TPVs,with a particular focus on solution-processed thin-film photovoltaics(PVs),including colloidal quantum dot PVs,metal halide perovskite PVs and organic *** applications of TPVs are also reviewed,with emphasis on agrivoltaics,smart windows and ***,current challenges and future opportunities in TPV research are pointed out.
The fiber optic sensing technology provides data support in structural health monitoring of the macro facilities, including design, construction, and maintenance of bridges, tunnels, ports and other infrastructures. I...
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The fiber optic sensing technology provides data support in structural health monitoring of the macro facilities, including design, construction, and maintenance of bridges, tunnels, ports and other infrastructures. In this paper, a distributed vibration sensing system is proved to be responsive to a single touch over a 1.8-m-long equivalent fiber segment, covering a vibration frequency from 5 Hz to 25 kHz. The sensing fiber was arranged as an S type layout on the bridge to recognize the standing state, windblown disturbance, and walking vibration. Moreover, the knocking and climbing events are recognized fiber laying spinning lines and hanging on the fences, respectively. The demonstration shows an accurate positioning and sensitive vibration monitoring applied on the automated three-dimensional(3D) printed bridge, which is applicable to all kinds of 3D printed facilities as intelligent sensory neuro-networks.
Large size titanium alloy parts are widely used in aerospace. However, they are difficult to manufacture using mechanical cutting technology because of severe tool wear. Electrochemical jet machining is a promising te...
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Large size titanium alloy parts are widely used in aerospace. However, they are difficult to manufacture using mechanical cutting technology because of severe tool wear. Electrochemical jet machining is a promising technology to achieve high efficiency, because it has high machining flexibility and no machining tool wear. However, reports on the macro electrochemical jet machining of large size titanium alloy parts are very scarce, because it is difficult to achieve effective constraint of the flow field in macro electrochemical jet machining. In addition, titanium alloy is very sensitive to fluctuation of the flow field, and a turbulent flow field would lead to serious stray corrosion. This paper reports a series of investigations of the electrochemical jet machining of titanium alloy parts. Based on the flow analysis and experiments, the machining flow field was effectively constrained. TB6 titanium alloy part with a perimeter of one meter was machined. The machined surface was smooth with no obvious machining defects. The machining process was particularly stable with no obvious spark discharge. The research provides a reference for the application of electrochemical jet machining technology to achieve large allowance material removal in the machining of large titanium alloy parts.
Endoplasmic reticulum(ER) viscosity has emerged as a new potential biomarker for hepatic fibrosis(HF). Herein, we report the first ER-targeting viscosity-responsive near-infrared(NIR) fluorescent probe HBT-PP for inve...
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Endoplasmic reticulum(ER) viscosity has emerged as a new potential biomarker for hepatic fibrosis(HF). Herein, we report the first ER-targeting viscosity-responsive near-infrared(NIR) fluorescent probe HBT-PP for investigations of HF *** twisted intramolecular charge transfer(TICT) and the excited state intramolecular proton transfer(ESIPT) are combined to endow HBT-PP with the selective response towards viscosity(~62-fold) and a super large stokes shift(~320 nm). HBT-PP mainly targets organelle ER and is able to image the drug-or alcohol-induced viscosity elevation in living cells. Significantly,HBT-PP was successfully applied to visualize the gender difference in HF and the protective role of estrogen in restraining HF progression. Of note, after 10 min of stain with HBT-PP, HF lesions showed a stage-based response, indicating the potential of this probe in fast and early diagnosis of HF. These results clearly demonstrated the promising application of HBT-PP as a new tool for exploring ER viscosity-involved physiological and pathological processes.
Fracture is the primary failure type for the UO2ceramic pellets,which are operated under irradiation and thermal processes,and physically confined by the *** this work,by combining closely coupled physical processes o...
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Fracture is the primary failure type for the UO2ceramic pellets,which are operated under irradiation and thermal processes,and physically confined by the *** this work,by combining closely coupled physical processes of heat conduction,heat transfer,and mechanical deformation with the cohesive phase field framework,we proposed a high-precision modeling of quasistatic cracking of three-dimensional (3D) UO2ceramic fuel pellets under high temperature and *** simulation results agree well with the experimental results,indicating that the proposed method has the potential to capture 3D crack modes in the interested time ***,we studied the relation of the 3D fracture patterns of fuel pellets with the peak power *** was found that the power level plays a critical role in determining the competition between radial and circumferential cracks,as well as transverse penetrating cracks.
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