Novel progress in the development of hydrogen storage materials

A new dehydrogenation mechanism for LiBH4, a new hydrogen storage material, has recently been

Effects of preparation temperature on electrochemical performance of nitrogen-enriched carbons

The activated nitrogen-enriched novel carbons (NENCs) were prepared by direct carbonization using polyaniline coating activated mesocarbon microbead composites as the precursor. Herein the influences of the carbonization temperature on the structure and morphology of the NENCs samples were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and N2 adsorption/desorption isotherm at 77 K. The electrochemical properties of the supercapacitors were characterized by cyclic voltammetry, galvanostatic charge/discharge, electrochemical impedance spectroscopy (EIS), cycle life, leakage current and self-discharge measurements in 6 mol/L KOH solution. The results demonstrate that the NENC samples carbonized at 600 °C show the highest specific capacitance of 385 F/g at the current density of 1 A/g and the lowest ESR value (only 0.93?). Furthermore, the capacity retention ratio of the NENCs-600 supercapacitor is 92.8 % over 2500 cycles.

Advances in experimental methods for root system architecture and root development

Plant roots play important roles in acquisition of water and nutrients, storage, anchoring, transport, and symbiosis with soil microorganisms, thus quantitative researches on root developmental processes are essential to understand root functions and root turnover in ecosystems,and at the same time such researches are the most difficult because roots are hidden underground. Therefore, how to investigate efficiently root functions and root dynamics is the core aspect in underground ecology. In this article, we reviewed some experimental methods used in root researches on root development and root system architecture, and summarized the advantages and shortages of these methods. Based on the analyses, we proposed three new ways to more understand root processes：（1） new experimental materials for root development;（2） a new observatory system comprised of multiple components, including many observatory windows installed in field, analysis software,and automatic data transport devices;（3） new techniques used to analyze quantitatively functional roots.

Generative artificial intelligence and its applications in materials science:Current situation and future perspectives

Generative Artificial Intelligence(GAI)is attracting the increasing attention of materials community for its excellent capability of generating required contents.With the introduction of Prompt paradigm and reinforcement learning from human feedback(RLHF),GAI shifts from the task-specific to general pattern gradually,enabling to tackle multiple complicated tasks involved in resolving the structure-activity relationships.Here,we review the development status of GAI comprehensively and analyze pros and cons of various generative models in the view of methodology.The applications of task-specific generative models involving materials inverse design and data augmentation are also dissected.Taking ChatGPT as an example,we explore the potential applications of general GAI in generating multiple materials content,solving differential equation as well as querying materials FAQs.Furthermore,we summarize six challenges encountered for the use of GAI in materials science and provide the corresponding solutions.This work paves the way for providing effective and explainable materials data generation and analysis approaches to accelerate the materials research and development.

Novel hard materials with controlled (W_(0.5)Al_(0.5))C grain shapes: in-situ high pressure preparation and mechanical properties

A novel hard material with various （W0.5Al0.5）C grain shapes was successfully prepared through mechanical alloying and in-situ high-pressure sintering process. X-ray diffraction apparatus and scanning electron microscopy were used to characterize the phase and the microstructures of the samples. The novel hard materials with ＂fibrous＂, ＂rounded＂ and ＂plate-like＂ grains, which do not contain sharp edges, have the improved mechanical properties. The bulk boundless （W0.5Al0.5）C hard material with various （W0.5Al0.5）C grain shapes possesses good mechanical properties and light weight. The formation mechanism for the non-equilibrium （W0.5Al0.5）C grains during in-situ high-pressure sintering is also discussed.

A review of recent advances of kesterite thin films based on magnesium,iron and nickel for photovoltaic application:insights into synthesis,characterization and optoelectronic properties

This review emphasizes the recent advancements and prospects of thin-film kesterite-based photovoltaic(PV)applications using magnesium,iron and nickel.The quest for novel materials employed in solar cells has resulted in incorporating these elements into the composition of kesterite as substitutes or modifiers(dopants)for zinc.This integration has induced notable repercussions on the structural,optoelectronics and morphological properties,which are reviewed.The first section of this paper offers a comprehensive review of the general characteristics of kesterite minerals.These crucial materials exhibit a high absorption coefficient(104 cm-1)and an optical band gap of 1.0-1.8 eV.Moreover,they are free of critical raw materials,non-toxic and sustainable.The second section depicts the substitution or modification of zinc by magnesium in kesterite.Additionally,this paper provides a comprehensive review of the quaternary and pentanary systems Cu_(2)MgSn(S,Se)_(4) and Cu_(2)Zn_(1-x)Mg_(x)SnS_(4),highlighting their advantages and drawbacks.In the last section,a review of the quaternary or pentanary systems is conducted,namely Cu_(2)ZnxFe_(1-x)SnS_(4) and Cu_(2)ZnxNi_(1-x)SnS_(4),along with their effects on optoelectronic properties.In conclusion,various methods for obtaining modified or substituted kesterite materials using magnesium,iron and nickel have demonstrated sustainability,scalability for industrial production and potential candidacy as substitutes for conventional PV materials.The prospects for pentanary materials(Cu_(2)Zn_(1-x)Mg_(x)SnS_(4),Cu_(2)Zn_(1-x)FexSnS_(4) and Cu_(2)Zn_(1-x)NixSnS_(4))are to overcome the efficiency record of kesterite reported in 2014,which was 12.6%for Cu_(2)ZnSn(S,Se)_(4),and to enhance its optoelectronic properties through synthesis conditions that comply with the principles of green chemistry.

Preparation of (Tb_(0.8)Y_(0.2))_3Al_5O_(12)transparent ceramic as novel magneto-optical isolator material

The ion substitution characteristics of Y3＋-doped （Tb0.sY0.2）3A15012 transparent ceramics synthesized by a solid-state reaction and vacuum sintering are investigated. The sample sintered at 1 680℃ exhibits the best optical properties, yielding a transmittance 〉75% from 900 to 1 600 nm. The Verdet constant of this sample at 632.8 nm is -108.79 rad.T-l.m-1. X-ray diffraction （XRD） results show that all of the samples have a pure garnet crystal structure without secondary phases. The microstructure of the samples reveals homogeneous grain sizes that averages 〈10μm.

A novel Mo-based oxide β-SnMoO4 as anode for lithium ion battery

Recently,the development of new electrode materials for lithium-ion batteries(LIBs)has received intensive attention.As an important family of inorganic materials,mixed Mo-based transition metal oxides system is focused as anode materials.In the present work,a simple route has been adopted for the synthesis of layered-flake-likeβ-SnMo04 Nano-assemblies,which have been explored as potential anode materials for the first time in lithium-ion battery(LIB).Overall,the current reports on metal molybdate as anode materials are still rarely.As the anode material for LIBs,it was observed that the fabricated anode is capable of delivering a steady state capacity of almost 400 mAh/g up to 300 cycles under the influence of200 mA/g current density.Further,the anode material is suitable for use as a rated capacity anode because of its high current density tolerance.The present study can be further extended for the generation of a wide variety of other novel materials for multidisciplinary energy related applications.

Screening outstanding mechanical properties and low lattice thermal conductivity using global attention graph neural network

Mechanical and thermal properties of materials are extremely important for various engineering and scientific fields such as energy conversion and energy storage.However,the characterization of these properties via high throughput screening at the quantum level,although highly accurate,is inefficient and very time-and resource-consuming.In contrast,prediction at the classical level is highly efficient but less accurate.We deploy scalable global attention graph neural network for accurate prediction of mechanical properties which bridge the gap between the accuracy at the quantum level and efficiency at the classical level.Using 10,158 elastic constants as training data,we trained the models on 5 mechanical properties,namely bulk modulus,shear modulus,Young’s modulus,Poisson’s ratio,and hardness.With the trained model,we predicted 775,947 data in search of materials with ultrahigh hardness.We further verify the recommended ultrahigh hardness materials by high precision first principles calculations,and we finally identify 20 structures with extreme hardness close to diamond,the hardest material in nature.Among those,two super hard materials are completely new and have not been reported in literature so far.We further recommend potential materials from bulk modulus prediction to search low lattice thermal conductivity,and we verify the thermal conductivity of 338 structures with first principles.Our results demonstrate that one can find materials with extreme mechanical properties recommended by graph neural network and low thermal conductivity material from bulk modulus prediction with minimal first principles calculations of the structures(only 0.04%)in the large-scale materials pool.

Designing a power plant with highest efficiency:results from SFB 561

The goal of Collaborative Research Centre(SFB) 561 "thermally highly loaded,porous and cooled multi-layer systems for combined cycle power plants" is to expand the current technological and scientific knowledge on power plants in order to achieve total efficiencies of 65% in a combined cycle power plant in the year 2025.Therefore,the aero-thermomechanical,structural-mechanical,materials' scientific and production fundamentals for the development of steam and gas turbine components that are able to withstand highest thermal loads are being worked out within this SFB.This means for the gas turbine that combustion chamber outlet temperatures of 1520℃ at 1.7MPa are to be attained.In order to control these high temperatures,it is not only required to develop new materials' solutions,including thermal barrier coatings,but also to apply improved cooling techniques,as for example effusion cooling.This novel cooling concept is to be realised through open-porous structures.These structures can consist of drilled open-porous multi-layer systems or open-porous metallic foams.The development of graded multi-layer systems is also extremely important,as the grading will enable the use of coolant in dependence of the requirements.The live steam parameters in the high pressure turbine are expected to be increased up to approximately 700℃ with pressure of 30MPa.These elevated steam parameters can be encountered with Ni-base alloys,but this is a costly alternative,associated with many manufacturing difficulties.Therefore,the SFB proposes cooling the highly loaded turbines instead,as this would necessitate the application of far less Ni-base alloys.To protect the thermally highly loaded casing,a sandwich material consisting of two thin face sheets with a core of a woven wire mesh is used to cover the walls of the steam turbine casing.The current state of the research shows that by utilising innovative cooling technologies a total efficiency of 65% can be reached without exceeding the maximum allowable material temperature,thereby prolonging the life-span.

Wavefront control of laser beam using optically addressed liquid crystal modulator

An optically addressed liquid crystal modulator for wavefront control of 1053 nm laser beam is reported in this paper.Its working principle, control method and spatial phase modulation capability are mainly introduced. A new method of measuring the relationship between gray level and phase retardation is proposed. The rationality of the curve is further confirmed by designing special experiments. According to the curve, several spatial phase distributions have been realized by this home-made device. The results show that, not only the maximum phase retardation is larger than2π for 1053 nm wavelength, but also the control accuracy is high. Compared with the liquid crystal on silicon type spatial light modulator, this kind of modulator has the advantages of generating smooth phase distribution and avoiding the black-matrix effect.