The global nitrogen cycle holds immense importance due to its crucial role in supporting life, supplying vital nutrients for plant growth, preserving environmental balance, and enabling the proper functioning of ecosy...
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The global nitrogen cycle holds immense importance due to its crucial role in supporting life, supplying vital nutrients for plant growth, preserving environmental balance, and enabling the proper functioning of ecosystems. However, human activities frequently disrupt this cycle, leading to the accumulation of nitrates and nitrites in water bodies. This accumulation causes environmental pollution and health risks. Traditional methods for treating nitrogen pollution, including biological, physical, and chemical approaches, have inherent limitations. In recent years, electrocatalysis has emerged as a promising and sustainable approach for nitrogen management. This technology offers superior efficiency, high selectivity, and environmental *** not only enables accurate detection of nitrogen pollutants in the environment but also facilitates their conversion into harmless nitrogen gas. Moreover, recent advancements have focused on the upcycling of nitrogen pollutants into valuable compounds,such as ammonia and urea. In this comprehensive review, we showcase the applications of electrocatalysis in sustainable nitrogen management. Specifically, we highlight its use in the sensing, removal, and upcycling of major nitrogen pollutants,including nitrate（NO3-）, nitrite（NO2-）, and nitric oxide（NO）. We discuss the use of catalysts, such as Pd alloys, Cu-based, and Fe-based materials, in electrochemical sensing and catalysis. Additionally, we explore recent advancements in the conversion of nitrogen pollutants into valuable compounds like ammonia and urea. The review also addresses current challenges and future opportunities in the field, including innovations in sensor and catalyst design, as well as large-scale treatment strategies. We anticipate that these perspectives will provide profound insights for effective nitrogen pollution control and sustainable utilization of nitrogen resources.
Equal channel angle pressing is recognized for its ability to refine alloy grains and alter grain orientation, thereby achieve better mechanical performance of the magnesium alloy. This study investigates the microstr...
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Equal channel angle pressing is recognized for its ability to refine alloy grains and alter grain orientation, thereby achieve better mechanical performance of the magnesium alloy. This study investigates the microstructures,dynamic recrystallization mechanism, texture development, and mechanical performance of GW94K(Mg–8.7Gd–4.18Y–0.42Zr wt. %) Mg alloy following ECAP-4 passes at 400°C and 3 mm/min. Results show that when high-temperature deformation is undertaken, twin formation is suppressed while dislocation slip is facilitated, increasing dislocation density during deformation. Following ECAP deformation, the sample displayed higher fracture elongation, TYS, and UTS than the as-solutioned GW94K alloy. In particular, the GW94K alloy performed well mechanically after ECAP-4 passes, with an ultimate TYS of 231 MPa, an UTS of 290 MPa, and an elongation of 14.8 %. DDRX and shear bands induce CDRX, both of which are important in plastic deformation. as well as in modifying microstructure and grain orientation during ECAP deformation.
G115 martensitic steel is anticipated to be one of the preferred candidate materials in ultra-super critical(USC)power plants with steam temperatures above 650℃.Microstructure evolutions and mechanical properties of ...
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G115 martensitic steel is anticipated to be one of the preferred candidate materials in ultra-super critical(USC)power plants with steam temperatures above 650℃.Microstructure evolutions and mechanical properties of G115 martensitic steel after applying various heat treatment processes were *** results demonstrate that the main precipitate in G115 martensitic steel after applying various heat treatment processes is M23C6 phase with Cr *** time required for M23C6 phase precipitation decreases with increasing secondary normalizing temperature and the extension in holding time according to its precipitation-temperature-time(PTT)*** fraction of M23C6 phase increases with increasing secondary normalizing temperature and holding time,which strengthens the inhibitory effect of precipitates on dislocations recovery and laths ***,G115 martensitic steel can obtain the best mechanical properties after applying the highest secondary normalizing temperature and the longest holding *** the current work,the excellent strength of G115 martensitic steel mainly derives from precipitates strengthening and laths strengthening.
The memory effect in a single-crystal spin glass (Cu0.92Mn0.08) has been measured using 1 Hz ac susceptibility techniques over a temperature range of 0.4–0.7Tg, and a model of the memory effect has been developed. A ...
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The memory effect in a single-crystal spin glass (Cu0.92Mn0.08) has been measured using 1 Hz ac susceptibility techniques over a temperature range of 0.4–0.7Tg, and a model of the memory effect has been developed. A double-waiting-time protocol is carried out where the spin glass is first allowed to age at a temperature below Tg, followed by a second aging at a lower temperature, Tw2, after it has fully rejuvenated. The model is based on calculating typical coincident growth of correlated regions at the two temperatures. It accounts for the absolute magnitude of the memory effect as a function of both waiting times and temperatures. The data can be explained by the memory loss being a function of the relative change in the correlated volume at the first waiting temperature because of the growth in the correlations at the second waiting temperature.
As global population rises,accompanied by escalating environmental pollution and climate change,numerous countries find themselves grappling with an acute scarcity of natural freshwater resources^([1]).Seawater desali...
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As global population rises,accompanied by escalating environmental pollution and climate change,numerous countries find themselves grappling with an acute scarcity of natural freshwater resources^([1]).Seawater desalination presents a compelling solution to this looming crisis,especially considering the oceans are Earth’s largest water reservoir^([2]).
Photoacoustic imaging,an acoustic imaging modality with potentially optical resolution in an optical turbid medium,has attracted great ***,the convergence of wavefront optimization and raster scanning in computational...
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Photoacoustic imaging,an acoustic imaging modality with potentially optical resolution in an optical turbid medium,has attracted great ***,the convergence of wavefront optimization and raster scanning in computational photoacoustic imaging leads to the challenge of fast mapping,especially for a spatial resolution approaching the acoustic deep-subwavelength *** a sparse sampling paradigm,compressive sensing has been applied in numerous fields to accelerate data acquisition without significant quality *** this work,we propose a dual-compressed approach for photoacoustic surface tomography that enables high-efficiency imaging with 3D spatial resolution unlimited by the acoustics in a turbid *** dual-compressed photoacoustic imaging with single-pixel detection,enabled by spatially optical modulation with synchronized temporally photoacoustic coding,allows decoding of the fine optical information from the modulated acoustic signal even when the variance of original photoacoustic signals is *** perform a proof-of-principle numerical demonstration of dual-compressed photoacoustic imaging, that resolves acoustic sub-acoustic-wavelength details with a significantly reduced number of measurements,revealing the potential for dynamic *** dual-compressed concept,which transforms unobtrusive spatial difference into spatio-temporal detectable information,can be generalized to other imaging modalities to re alize efficient,high-spatial-resolution imaging.
In low-density steel,κ-carbides primarily precipitate in the form of nanoscale particles within austenite ***,their precipitation within ferrite matrix grains has not been comprehensively explored,and the second-phas...
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In low-density steel,κ-carbides primarily precipitate in the form of nanoscale particles within austenite ***,their precipitation within ferrite matrix grains has not been comprehensively explored,and the second-phase evolution mechanism during aging remains *** this study,the crystallographic characteristics and morphological evolution ofκ-carbides in Fe-28Mn-10Al-0.8C(wt%)low-density steel at different aging temperatures and times and the impacts of these changes on the steels’microhardness and properties were comprehensively *** different heat treatment conditions,intragranularκ-carbides exhibited various morpho-logical and crystallographic characteristics,such as acicular,spherical,and short rod-like *** the initial stage of aging,acicularκ-carbides primarily precipitated,accompanied by a few spherical carbides.κ-Carbides grew and coarsened with aging time,the spherical carbides were considerably reduced,and rod-like carbides *** hardness testing demonstrated that the material’s hardness was affected by the volume fraction,morphology,and size ofκ-*** aging at higher temperatures led to an increase in carbide size and volume fraction,resulting in a gradual rise in *** deformation,the primary mechanisms for strengthening were dislocation strengthening and second-phase *** on these findings,potential strategies for improving material strength are proposed.
Multifunctional fibers with high mechanical strength enable advanced applications of smart textiles,robotics, and biomedicine. Herein, we reported a one-step degumming method to fabricate strong, stiff, and humidity-r...
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Multifunctional fibers with high mechanical strength enable advanced applications of smart textiles,robotics, and biomedicine. Herein, we reported a one-step degumming method to fabricate strong, stiff, and humidity-responsive smart cellulosic fibers from abundant natural grass. The facile process involves partially removing lignin and hemicellulose functioning as glue in grass, which leads to the separation of vessels,parenchymal cells, and cellulosic fibers, where cellulosic fibers are manufactured at kilogram scale. The resulting fibers show dense and unidirectional fibril structure at both micro-and nano-scales, which demonstrate high tensile strength of ～0.9 GPa and Young's modulus of 72 GPa, being 13-and 14-times higher than original grass. Inspired by stretchable plant tendrils, we developed a humidity-responsive actuator by engineering cellulosic fibers into the spring-like structures, presenting superior response rate and lifting capability. These strong and smart cellulosic fibers can be manufactured at large scale with low cost, representing promising a fiber material derived from renewable and sustainable biomass.
Solid oxide electrolytic cell(SOEC) is an energy conversion device that transfers electrical energy into chemical energy. It has garnered significant attention due to its high efficiency and thick current density. The...
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Solid oxide electrolytic cell(SOEC) is an energy conversion device that transfers electrical energy into chemical energy. It has garnered significant attention due to its high efficiency and thick current density. The oxygen evolution reaction(OER) and the hydrogen evolution reaction(HER) are two crucial half-reactions of SOEC, while both require excellent electrochemical performance under high-temperature and high-humidity ***, high catalytic activity and good stability of electrode materials are crucial for the practical application of SOEC. The perovskite structure of the oxygen electrodes has outstanding OER activity, while metal ceramic and metal oxide hydrogen electrodes possess good redox properties. This article firstly demonstrates the influence of the physical and electrochemical properties of electrode materials on the performance of SOEC, then illustrates the optimization strategies for electrode materials to improve electrolysis efficiency and extend service ***, the research priorities for the future development of electrode material are summarized.
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