Nb-and Ta-doped(Hf,Zr,Ti)C multicomponent carbides with enhanced oxidation resistance at 2500℃

Enhancing oxidation resistance of multicomponent carbides above 2000℃is critical for their thermal protection applications.For this purpose,novel Nb-and Ta-doped(Hf,Zr,Ti)C multicomponent carbides were designed to improve their oxidation resistance at 2500℃.The results demonstrated that Nb and Ta doping reduced the oxidation rate constant by 16.67%and 25.17%,respectively,thereby significantly improving the oxidation resistance of(Hf,Zr,Ti)C.This enhancement was attributed to the changes in oxycarbide composition and distribution within the oxide layer by adding Nb and Ta.Owing to the different oxidation tendencies of the constituent elements,a distinctive structure was formed in which(Hf,Zr)O_(2)served as a skeleton,and various oxycarbides were dispersed throughout the oxide layer.The doped Nb and Ta were retained within oxycarbides,retarding the diffusion of oxygen into the lattice.More importantly,the addition of Nb and Ta reduced the size of oxycarbides,decreasing both size and quantity of the pores in the oxide layer and facilitating the formation of a more effective oxygen barrier.

Metagenomics analysis identifies oral Streptococcus as potential biomarkers for nasopharyngeal carcinoma

Nasopharyngeal carcinoma(NPC)is a malignancy originating from the nasopharyngeal epithelial cells.Although some studies have identified potential biomarkers for early diagnosis of NPC based on metabolomics data(Chen et al.,2023;Zhou et al.,2023)and Epstein-Barr virus subtypes(Xu et al.,2019),their effectiveness and applicability need further investigation,particularly when consideringthe roles of oral microbiota.

Light-responsive and corrosion-resistant gas valve with non-thermal effective liquid-gating positional flow control

Safe and precise control of gas flow is one of the key factors to many physical and chemical processes,such as degassing,natural gas transportation,and gas sensor.In practical application,it is essential for the gas-involved physicochemical process to keep everything under control and safe,which significantly relies on the controllability,safety,and stability of their valves.Here we show a light-responsive and corrosion-resistant gas valve with non-thermal effective liquid-gating positional flow control under a constant pressure by incorporating dynamic gating liquid with light responsiveness of solid porous substrate.Our experimental and theoretical analysis reveal that the photoisomerization of azobenzene-based molecular photoswitches on the porous substrate enabled the gas valve to possess a light-responsive and reversible variation of substantial critical pressure of non-thermal effective gas flow switch.Moreover,the chemically inert gating liquid prevented the solid substrate from corrosion and,by combining with the high spatiotemporal resolution of light,the gas valve realizes a precisely positional open and close under a steady-state pressure.The application demonstrations in our results show the potentials of the new gas valve for bringing opportunities to many applications,such as gas-involved reaction control in microfluidics,soft actuators,and beyond.

Durable and Flexible Bio-assembled RGO-BC/BC Bilayer Electrodes for Pressure Sensing

The new generation of electronics tends to be well-performed,facile and environmentally friendly.Here,we report a bio-assembled sensitive pressure senor based on reduced graphene oxide-bacterial cellulose/bacterial cellulose(RGO-BC/BC)bilayer films,integrated by bacteria in one step.The advantage of this integration is that there is strong nanofiber connection between the conductive RGO-BC and insulative highly compressible porous BC layer,which confers RGO-BC/BC film electrode with good robustness,tailorability,flexibility and wearability.Without extra bonding-interface or postprocessing,the RGO-BC/BC bilayer films could be directly assembled into pressure sensing devices.Ascribed from the good reversible compressibility of the BC layer and incorporated bilayer structure,the pressure sensor performs good sensitivity and excellent durability and bending stability.The facile sensitive capacitive sensor could monitor the human hand or finger motion in real time.The sensing array is able to detect the spatial distribution of pressure mounted in the flat plane as well as curved surface of human body,succeeding in the correction of human walking posture for health care.The e-skins are potential in wearable electronics,artificial intelligence,soft robots,healthcare etc.

Alternative photothermal/electrothermal hierarchical membrane for hypersaline water treatment

Over the last decades,the treatment of the large quantities of hypersaline wastewater generated by conventional industries,inland desalination,and fossil-fueled power plants has been an important economic issue and also an inescapable green issue.Here,we developed a versatile interfacial heating membrane with alternating utilization of electricity or solar energy for hypersaline water treat-ment.This hierarchical membrane functions both as a separation membrane and an interface heater,which can quickly(<0.1 s)convert electricity or solar energy into heat to evaporate the outermost layer of hypersaline water.For 10wt% hyper-saline water,the freshwater production rate can reach 16.8kg/m^(2)⋅h by applying a voltage of 10 V and 1.36 kg/m^(2)⋅h under 1-sun illumination.Moreover,it exhibits high electrochemical resistance to corrosion and therefore remains stable tack-ling hypersaline water(>5 wt%),with a high salt rejection rate of 99.99%.This system shows an efficient desalination strategy that can provide fresh water from brines for agriculture and industry,and even for daily life.

ZnS/Bacterial Cellulose/Epoxy Resin(ZnS/BC/E56) Nanocomposites with Good Transparency and Flexibility

ZnS/bacterial cellulose/epoxy resin （ZnS/BC/E56） nanocomposites with good transparency and flexibil-ity were prepared and characterized. When the precursor Zn^2＋ concentrations were not more than I wt%, the size of the introduced ZnS nanoparticles was smaller than 50 nm and the distribution was homo-geneous within the composites. Under the condition, outstanding transmittance more than 70g in the visible light was obtained. By incorporation of ZnS nanoparticles with excellent thermo-optic stability to the composites, the thermo-optic coefficient was obviously increased from -361 × 10^-6 to -310 × 10^-6K^-1. The good flexibility, optical and mechanical properties endow the nanocomposites potential applica- tions in the flexible optoelectronic materials.

Tuning the Charge Transport Property of Naphthalene Diimide Derivatives by Changing the Substituted Position of Fluorine Atom on Molecular Backbone

Three naphthalene diimides(2,3 and 4)fused with 2-(1,3-dithiol-2-ylidene)-2-fluorophenylacetonitrile moieties were designed and synthesized.Due to the different substituted positions of fluorine atom on the phenyl group,the solution-processed thin films of 2 and 3 operated in air as n-channel transistors,while the films of 4 performed as ambipolar transistors,indicating that the variation of substituted position of fluorine atom on molecular backbone may tune the material’s charge transport behavior.