The energy used for regulating building temperatures accounts for 14% of the primary energy consumed in the U.S. One-quarter of this energy is leaked through inefficient glass windows in cold weather. The development of transparent composites could potentially provide affordable window materials with enhanced energy efficiency. Transparent wood as a promising material has presented desirable performances in thermal and light management. In this work, the performance of transparent wood is optimized toward an energy efficient window material that possesses the following attributes: 1) high optical transmittance (≈91%), comparable to that of glass; 2) high clarity with low haze (≈15%); 3) high toughness (3.03 MJ m −3 ) that is 3 orders of magnitude higher than standard glass (0.003 MJ m −3 ); 4) low thermal conductivity (0.19 W m −1 K −1 ) that is more than 5 times lower than that of glass. Additionally, the transparent wood is a sustainable material, with low carbon emissions and scaling capabilities due to its compatibility with industryadopted rotary cutting methods. The scalable, high clarity, transparent wood demonstrated in current work can potentially be employed as energy efficient and sustainable windows for significant environmental and economic benefits.

In this paper, a multi-scale Eulerian-Lagrangian CFD model based on OpenFOAM has been constructed, which takes into account heat and mass transfer, pyrolysis, homogeneous and heterogeneous reactions, radiation, as well as the interactions between the continuous gas phase and discrete particles. The proposed model is validated and applied to a lab-scale biomass entrained flow reactor. The operating temperatures are high (1000-1400 °C) and influences of five operating parameters (reactor temperature, steam/carbon molar ratio, excess air ratio, biomass type, and particle size) on the gasification behavior are explored. Results show that an increase in the reactor temperature has positive effect on both the H2 and CO productions; increasing the steam/carbon ratio increases the H2 production but decreases the CO production; increasing the excess air ratio decreases both the H2 and CO productions; the variations in the gas product for the four biomasses studied are not so significant due to similar biomass nature and hence one type can be replaced by another without any major consequences in the gasification performance; and both the CO and H2 productions and carbon conversion decrease with an increase in particle size. Moreover, the predicted results follow the same trend as the experimental data available in the literature. Quantitative comparisons are also made and the agreement is good.

A comprehensive CFD-DEM numerical model has been developed to simulate the biomass gasification process in a fluidized bed reactor. The methodology is based on an Eulerian-Lagrangian concept, which uses an Eulerian method for gas phase and a discrete element method (DEM) for particle phase. Each particle is individually tracked and associated with multiple physical (size, density, composition, and temperature) and thermo-chemical (reactive or inert) properties. Particle collisions, hydrodynamics of dense gas-particle flow in fluidized beds, turbulence, heat and mass transfer, radiation, particle shrinkage, pyrolysis, and homogeneous and heterogeneous chemical reactions are all considered during biomass gasification with steam. A sensitivity analysis is performed to test the integrated model's response to variations in three different operating parameters (reactor temperature, steam/biomass mass ratio, and biomass injection position). Simulation results are analyzed both qualitatively and quantitatively in terms of particle flow pattern, particle mixing and entrainment, bed pressure drop, product gas composition, and carbon conversion. Results show that higher temperatures are favorable for the products in endothermic reactions (e.g. H2 and CO). With the increase of steam/biomass mass ratio, H2 and CO2 concentrations

The exploration of new catalytic hosts is highly important to tackle the sluggish electrochemical kinetics of sulfur redox for achieving high energy density of lithium–sulfur batteries. Herein, for the first time, we present high‐entropy oxide (HEO, (Mg0.2Mn0.2Ni0.2Co0.2Zn0.2)Fe2O4) nanofibers as catalytic host of sulfur. The HEO nanofibers show a synergistic effect among multiple metal cations in spinel structure that enables strong chemical confinement of soluble polysulfides and fast kinetics for polysulfide conversion. Consequently, the S/HEO composite displays the high gravimetric capacity of 1368.7 mAh g−1 at 0.1 C rate, excellent rate capability with the discharge capacity of 632.1 mAh g−1 at 5 C rate, and desirable cycle stability. Furthermore, the S/HEO composite shows desirable sulfur utilization and good cycle stability under a harsh operating condition of high sulfur loading (4.6 mg cm−2) or low electrolyte/sulfur ratio (5 μL mg−1). More impressively, the high volumetric capacity of 2627.9 mAh cm−3 is achieved simultaneously for the S/HEO composite due to the high tap density of 1.92 g cm−3, nearly 2.5 times of the conventional sulfur/carbon composite. Therefore, based on high‐entropy oxide materials, this work affords a fresh concept of elevating the gravimetric/volumetric capacities of sulfur cathodes for lithium–sulfur batteries.

2D polymers (2DPs) have attracted increasing interests in sensors, catalysis, and gas storage applications. Furthermore, 2DPs with unique band structure and tunable photophysical properties also have immense potential for application in photonic neuromorphic computing. Here, photonic synaptic transistors based on 2DPs as the light‐tunable charge‐trapping medium are developed for the first time. The resulted organic transistors can successfully emulate common synaptic functions, including excitatory postsynaptic current, pair‐pulse facilitation, the transition of short‐term memory to long‐term memory, and dynamic filtering. Benefitting from the high photosensitivity of the 2DP, the devices can be operated under a low operating voltage of −0.1 V, and achieve an ultralow energy consumption of ~0.29 pJ per event. In addition, the heterostructure formed between the 2DP and organic semiconductor enables spectrum‐dependent synaptic responses, which facilitates the simulation of visual learning and memory processes in distinct emotional states. The underlying mechanism of spectrum‐dependent synaptic‐like behaviors is systematically validated with in situ atomic force microscopy based electrical techniques. The spectrum‐enabled tunability of synaptic behaviors further promotes the realization of optical logic functions and associative learning. This work inspires the new application of 2DPs in photonic synapses for future neuromorphic computing.

Sulfur–carbon composites were prepared by an in situ sulfur deposition route developed for the heterogeneous nucleation of sulfur into nanopores of conductive carbon black (CCB) by fumigation of Na2S4/CCB powder with HCl. The sulfur–carbon composites demonstrate enhanced reversible capacity and stable cycle performance.

Tremendous efforts have been dedicated to developing cost-effective energy efficiency techniques to lower the energy consumption of buildings. [4,5] The low energy cost of energy efficient buildings can substantially lower their carbon footprint and at the same time provide a more uniform temperature throughout the space and a more comfortable and healthy indoor environment. [6] Traditional structural materials including steels, concretes, alloys, and carbon fibers have been widely used in buildings due to their good mechanical properties. However, most of them fail to meet the simultaneous needs of mechanical and thermal insulation properties for advanced energy-efficient buildings because of their relatively high thermal conductivities. Moreover, these materials are nonrenewable, and have high costs and greenhouse gas emissions during their extraction/synthesis processes, which compromises their efficacy in a sustainable society. Compared with conventional building materials, green building materials can enhance indoor environmental quality and thus bring us a more satisfying workplace for the buildings' occupants, and in turn, improve workforce productivity. Wood is a sustainable and versatile building material that stores, rather than emits, carbon dioxide. A reduction of 2432 metric tons of carbon dioxide can be achieved by using wood. [7,8] Recently, the development of using advanced wooden materials for construction has raised substantial interest. [9] Many recent projects such as the tall wood building in Vancouver and the Timber city have used wood as the main constructional material due to its economic and environmental benefits over current constructional materials like steel and concrete, which are nonrenewable and have high embodied energies. [10] Despite the economic and environmental benefits, the current woodbased panels still face many challenges. Natural wood cannot meet the mechanical performance requirements promoted by the Department of Energy (DOE) programs for energy efficient buildings. The mechanical strength of natural wood prevents its applications to mid-rise and high-rise buildings. [11] Developing strong and thermal insulating structural materials is highly desirable for an energy-efficient world. Nonetheless, most of The development of high-performance structural materials for high-rise building applications is critical in achieving the energy conservation goal mandated by the Department of Energy (DOE). However, there is usually a trade-off between the mechanical strength and thermal insulation properties for these materials. Here, the optimization is demonstrated of natural wood to simultaneously improve the mechanical properties and thermal insulation for energy efficient high-rise wood buildings. The improved wood material (strong white wood) features a complete delignification followed by a partial densification process (pore structure control), which enables substantially enhanced mechanical properties (≈3.4× in tensile strength, ≈3.2× in toughness) and reduced thermal conduct...

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