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Disordered hyperuniformity (DHU) is a recently discovered novel state of amorphous systems characterized by strongly suppressed density fluctuations at large length scales as in crystalline materials, which offers great potential for achieving unusual mechanical, electronic, and photonic properties. However, despite the fundamental and technological importance of thermal transport in amorphous solids, the effect of DHU remains largely unexplored. Here, we theoretically study thermal transport in a class of two-dimensional DHU materials—monolayer amorphous carbon (MAC). Beginning with a perfect graphene lattice, we continuously apply Stone-Wales transformations to generate a series of MAC models with varied degrees of disorder and defects, which are quantified through comprehensive structural analysis including the so-called hyperuniformity index ( H ), where a smaller H indicates a higher degree of hyperuniformity. Subsequently, we conduct molecular dynamics simulations to obtain the thermal conductivity ( κ ). A significant correlation between the thermal transport behavior and degree of hyperuniformity is observed, with the room-temperature κ decreasing from 26.3 to 5.3 W m −1 K −1 while H is tuned from 0.0004 to 0.024. Remarkably, two distinct transport regimes are identified, including a nearly-DHU regime at small H (< 0.005) where κ drops sharply and a non-DHU region at larger H where κ becomes relatively flat. Mode-resolved analysis reveals longer lifetime and higher participation ratio for the heat carriers in nearly-DHU MAC, implying that the hidden long-range correlations could support extended modes that enhance transport. Our work highlights the impact of DHU on the thermal properties of amorphous materials and represents a conceptual advancement that is worthy of future exploration.

Capturing CF 4 is crucial for mitigating its substantial greenhouse effect and environmental impact in the microelectronics industry. Here we employed a hybrid approach combining grand canonical ensemble Monte Carlo molecular simulations and neural network models to screen over 100 amorphous materials for N 2 /CF 4 gas adsorption storage and separation. Materials with higher adsorption capacities exhibited densities around 0.7 to 1.0 g/cm 3 and pore sizes within the range of 1.4–1.6 Å. At 298 K and 1000 kPa, HCP-Colina-id0016 and aCarbon-Bhatia-id001 demonstrated the highest CF 4 adsorption, reaching 5.65 and 5.34 mmol/g, respectively. For the separation of N 2 /CF 4 mixtures, considering the comprehensive CF 4 adsorption selectivity and capacity, we recommend HCP-Colina-id0016 at high pressure conditions (4500 kPa) and aCarbon-Bhatia-id001 at medium to low pressures (below 500 kPa). The separation of mixtures is more favorable at low CF 4 concentrations, becoming more challenging as CF 4 concentration increases. Additionally, the Ideal Adsorbed Solution Theory (IAST) accurately predicted the separation of the N 2 /CF 4 system on amorphous materials. We found that the genetic algorithm-optimized neural network (GA-BP) outperformed the standalone backpropagation neural network (BP) in accurately predicting the relationship between material structural properties and CF 4 adsorption, showing its potential for widespread application in large-scale material screening.

In the present study, semi-crystalline polypropylene (PP) and amorphous polystyrene (PS) were adopted as matrix materials. After the exothermic foaming agent azodicarbonamide was added, injection molding was implemented to create samples. The mold flow analysis program Moldex3D was then applied to verify the short-shot results. Three process parameters were adopted, namely injection speed, melt temperature, and mold temperature; three levels were set for each factor in the one-factor-at-a-time experimental design. The macroscopic effects of the factors on the weight, specific weight, and expansion ratios of the samples were investigated to determine foaming efficiency, and their microscopic effects on cell density and diameter were examined using a scanning electron microscope. The process parameters for the exothermic foaming agent were optimized accordingly. Finally, the expansion ratios of the two matrix materials in the optimal process parameter settings were compared. After the experimental database was created, the foaming module of the chemical blowing agents was established by Moldex3D Company. The results indicated that semi-crystalline materials foamed less due to their crystallinity. PP exhibits the highest expansion ratio at low injection speed, a high melt temperature, and a low mold temperature, whereas PS exhibits the highest expansion ratio at high injection speed, a moderate melt temperature, and a low mold temperature.

Photonic crystals consist of artificial periodic structures of dielectrics, which have attracted much attention because of their wide range of potential applications in the field of optics. We may also fabricate artificial amorphous or quasicrystalline structures of dielectrics, i.e. photonic amorphous materials or photonic quasicrystals. So far, both theoretical and experimental studies have been conducted to reveal the characteristic features of their optical properties, as compared with those of conventional photonic crystals. In this article, we review these studies and discuss various aspects of photonic amorphous materials and photonic quasicrystals, including photonic band gap formation, light propagation properties, and characteristic photonic states.

Introduction: Bottom ash (BA) constitutes a significant by-product obtained during the incineration of municipal solid waste in waste-to-energy (WtE) plants. BA is a heterogeneous material made of different fractions, glass, minerals, metals, and unburned residual organic matter. Due to the non-hazardous nature of the unburned material, BA can be effectively recycled, becoming a valuable resource. However, BA displays a high content of potentially toxic elements (PTEs) within its finer grain size. The presence of these elements raises concerns regarding the potential toxicity associated with BA. Materials and methods: The release of PTEs in the smaller fraction (0.063–0.2 mm; 0.3–0.5 mm; 2–4 mm; bulk <4 mm) of BA collected from the Parma WtE plant was investigated using a new five-step sequential extraction procedure (SEP). Through this method, both leached solutions and solid residues were analyzed by inductively coupled plasma-mass spectroscopy (ICP-MS), X-ray powder diffraction (XRPD), and X-ray fluorescence (XRF) analysis. This integrated approach provided valuable insights into the mineralogy, chemical composition, and PTEs leachability of BA. Results and discussion: The novelty of this work is the development of a new SEP protocol specifically designed and planned for an anthropogenic material such as BA. The weight reduction recorded after each step is linked to the progressive disappearance of both crystalline and amorphous phases. Water-soluble phases, such as salts, are the first to react, followed by the carbonate fraction in the second step. At the end of the procedure, only quartz, corundum, and Ti-oxide are identified. Among the PTEs, Pb exhibits the highest release, particularly during the acid attack, followed by Zn. The significant release of Ni during the oxidizing and reducing steps can potentially be linked to hydroxides and metallic alloys, respectively. The integration of XRF and Rietveld refinement results on solid residues enabled the identification of several types of amorphous materials and their chemical evolution during the sequential extraction.

This article uses Ti 43 Zr 27 Mo 5 Cu 10 Be 15 amorphous brazing material to experiment with 20*17*1 mm 304 stainless steel and 316L stainless steel sheets at different heating temperatures and holding times. Using an optical microscope, x-ray diffraction, scanning electron microscope, Shear strength, and Vickers hardness, the microstructure, element distribution, diffusion, and mechanical properties of joints of 304 and 316L stainless steel brazed with amorphous alloy as filler metal were studied. The results indicate that the brazing seam (FZ) will be generated during the brazing process. β-Ti improves its mechanical properties, and the matrix at the center of the brazing seam is still an amorphous phase. However, due to the diffusion of elements, intermetallic compounds are generated in the brazing seam, resulting in poor joint formation and cracking. It provides a specific theoretical basis and experimental basis for the engineering application of stainless steel brazing or other structural material parts using Ti and Zr-based amorphous alloy as brazing material.

The fracture and crack growth of materials can be practically and conveniently predicted through numerical analysis and linear elastics fracture mechanics. On this basis, the current study aims to present experimental work supported by a numerical technique for mimicking the crack propagation by Version 5.6 of COMSOL Multiphysics (version 5.6), used for the simulation of the coating made from Fe-based amorphous material with a thickness of 300 µm. The paper shows the effects of mixed-mode loading on cohesive zone parameters attained from load-crack mouth opening displacement (CMOD) curves. The microstructure dominates the fracture, which in mode I is altered from all-transgranular cleavage to nearly all-intergranular structure in mode II. Two common criteria for failure are linked to the mixed-mode results: Maximum energy release rate criterion (Maximum G) and maximum tensile stress criterion (Maximum S). However, distinguishing between the two criteria is made impossible by the large scatter in the data. The stress intensity factor is the basis for the. The stress intensity factor is the leading parameter facilitated by the singular element and should be estimated with accuracy. With the aim of comparing each criterion and illustrating the numerical schemes’ robustness, a number of examples are presented. It can be concluded that the Maximum G and Maximum S were successful and accurate in predicting the propagation of the Fe-based amorphous material prepared on mild steel.

Amorphous materials have no long-range order, but there are ordered structures at short range (2–5 Å), medium range (5–20 Å) and even longer length scales 1 – 5 . While regular 6 , 7 and semiregular polyhedra 8 – 10 are often found as short-range ordering in amorphous materials, the nature of medium-range order has remained elusive 11 – 14 . Consequently, it is difficult to determine whether there exists any structural link at medium range or longer length scales between the amorphous material and its crystalline counterparts. Moreover, an amorphous material often crystallizes into a phase of different composition 15 , with very different underlying structural building blocks, further compounding the issue. Here, we capture an intermediate crystalline cubic phase in a Pd-Ni-P amorphous alloy and reveal the structure of the medium-range order, a six-membered tricapped trigonal prism cluster (6M-TTP) with a length scale of 12.5 Å. We find that the 6M-TTP can pack periodically to several tens of nanometres to form the cube phase. Our experimental observations provide evidence of a structural link between the amorphous and crystalline phases in a Pd-Ni-P alloy at the medium-range length scale and suggest that it is the connectivity of the 6M-TTP clusters that distinguishes the crystalline and amorphous phases. These findings will shed light on the structure of amorphous materials at extended length scales beyond that of short-range order. An intermediate cube phase with a medium-range order structure is identified in Pd-Ni-P metallic glass, which links the amorphous and crystalline phases.

Several types of amorphous material in ultracataclastic core samples recovered from 3194 m and 3294 m depth of the main bore hole of the San Andreas Fault Observatory at Depth are identified and described with transmission electron microscopy and scanning electron microscopy. We observed (1) amorphous material on a slickenside surface, (2) glassy bands contained in an ultracataclastic matrix and (3) amorphous rims surrounding quartz or feldspar clasts. Chemical analyses of the amorphous material reveal that silica content is slightly enriched or similar as in the adjacent matrix. We suggest that all amorphous material was formed by comminution of clasts (crush‐origin pseudotachylytes) rather than by melting (melt‐origin pseudotachylytes). The observed amorphous phases may act as lubricating layers that reduce friction in the San Andreas Fault.

The importance of amorphous matter content in precursors for alkaline activation was studied by means of adjustment of precursors (four types) amorphous matter content to the same level (42%) and by measurement of strength of prepared Alkali Activated Materials (AAM). It was found that the same content of amorphous matter is not ensuring the same strength. The precursor performance is controlled also by the chemical composition of its amorphous portion.