High-energy Structure Research Articles

The Effects of Different Ultrasonic Composite Surface Modifications on the Properties of H13 Steel for Shield Tunnel Machine Cutter Ring

Tunnel boring machines (TBMs) are exposed to the impact of the ground shattering force and the friction of sandstone during excavation work, and are prone to wear and breakage, and other failures. Traditional heat treatment processes cannot simultaneously achieve the required high-energy composite structure of hard external and tough internal properties for cutter rings, leading to inadequate wear resistance and impact toughness under working conditions. This study utilizes H13 steel as the base material, and based on a study of carburizing, nitriding, and ultrasonic impact processes for H13 steel analyzing the effects of different high-energy composite modification processes on the hardness distribution, microstructure, and residual stress of H13 steel, the mechanisms by which high-energy composite modification processes affect the wear resistance and impact resistance of H13 steel are revealed. The results indicate that the wear amount and impact toughness of the sample subjected to carburizing and ultrasonic surface rolling composite strengthening were 1.9 mg and 27.34 J/cm2, demonstrating the best wear and impact resistance. This combination of properties allows the H13 steel cutter ring to achieve the optimal overall performance in terms of wear resistance and impact resistance.

Novel self-healing glass-like CexOY film on a Flash-PEO coated AZ31B Mg alloy

The aim of this work is to develop a glass-like CexOy coating to seal the pores of a Flash-PEO coated AZ31B Mg alloy and simultaneously provide smart self-healing corrosion protection. The cerium sol was synthesized using cerium acetate as main precursor by sol-gel method. SEM micrographs revealed that upon cerium sol deposition, the pores of the oxide coating were effectively sealed, resulting in a double-layer coating system and thereby in a big reservoir of cerium ions (Ce3+/Ce4+). The glassy character of the cerium coating, confirmed by X-Ray diffraction, implies that cerium exists in Ce3+ and Ce4+ ionic states enclosed in a high internal energy structure which facilitate the diffusion of cerium ions to active cathodic zone. Electrochemical Impedance Spectroscopy (EIS), X-Ray Diffraction (XRD), and Raman spectroscopy were used to explore the active corrosion protection of the CexOy sol-gel coating. The corrosion inhibition mechanism involves the migration of cerium ions and the precipitation of insoluble-crystalline cerium compounds (CeO2). The coating demonstrated self-healing properties, presenting a promising alternative to traditional chrome conversion coatings (CCC).

µSR studies for radical reactions of unsaturated organophosphorus compounds

In this paper, the µSR studies of some unsaturated organophosphorus compounds containing heavier congeners of cyclobutane-1,3-diyl and anthracene are reviewed by discussing the usefulness of µSR for main group chemistry. The regioselective addition of muonium (Mu = [µ+e–]) to one of the skeletal phosphorus atoms in an electron-donating air-stable crystalline 1,3-diphosphacyclobutane-2,4-diyl leading to the paramagnetic 4-membered P-heterocycle was characterized by the Δ1 (ΔM = ± 1) resonance signal observed by muon (avoided) level-crossing resonance (µLCR). Meanwhile, a crystalline 1,3-diphosphacyclobutane-2,4-diyl bearing an electron-deficient nitrogen heterocyclic unit was analyzed by transverse-field muon spin rotation (TF-µSR) to characterize predominant muoniation at the skeletal radical carbon centre. A 9-phosphaanthracene bearing the trifluoromethyl (CF3) stabilizing groups at the peri positions was also investigated from the views of radical reactivity, and the regioselective addition of muonium to the skeletal sp2-type phosphorus atom was characterized by the muon hyperfine coupling (hfc) constant observed by TF-µSR and the Δ0 (ΔM = 0) signal of µLCR. The light mass of muon (Mass = 0.1134 amu) causes the larger zero-point energy and promotes the high-energy molecular structure in which the fused aromatic rings are almost flat, although the CF3 groups would prefer the non-planar saddle-like 9-phosphaanthracene skeleton.

Last piece of the puzzle: lead-assisted assembly of an arsenopalladate nanostar as an antitumor metallodrug

Access to the long-sought nanostar of arsenopalladate is workable via host–guest assembly. The arsenate functions of such POP metallodrugs drive the ROS-induced apoptosis with great antitumor potential.

Theoretical developments on the initial state in relativistic particle collisions

We discuss recent progress towards developing accurate initial state descriptions for heavy ion collisions focusing on weak coupling based approaches, that enable one to constrain the high-energy structure of nuclei from deep inelastic scattering or proton-nucleus collisions. We review recent developments to determine the event-by-event fluctuating nuclear geometry, to describe gluon saturation phenomena at next-to-leading order accuracy, and to include longitudinal dynamics to the initial state descriptions.

Preliminary Insight on Neural Correlates of Quranic Impacts on Cognition: A Review

Perception and synchronization of rhythms are vital for human health and social functioning, and cognition, which calls for rhythmic acoustic stimulation as a potential therapy. Quranic sound contains high energy and rhythmic structure of sound signal which has a soothing effect, comfort human feeling and evokes the limbic and reward systems. However, less is known about how the neural interaction between brain rhythms and sound rhythms. Here we review the Quranic listening effects on human cognition from the neuronal correlates perspective. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) was used to review articles from no earlier than 2000 for scientific reports in the English language. Navigation terms used were ‘Quran and cognition’, ‘Quran and memory’ and ‘Quran and attention’. Nine papers were fulfilled our criteria and assessed. We discussed issues related to the neural correlations regarding Quranic impacts on cognition. Three main factors contribute to the effects of the Quranic listening on human cognition: linguistic rhythms, physical aspect, and neuroscientific aspect. The neuroscientific aspect delineated the brain activation due to brainwave entrainment, event-related desynchronization and synaptic plasticity, which were associated with attention, memory and speech fluency. Quranic recitation contains rhythmical sound and physical characteristics that interact with the human’s auditory system, producing changes in the brain oscillations and improving cognitive performance such as attention, memory and speech fluency. Instead of a conclusion, it is hoped that this review entices other researchers to explore further scientific and health benefits of the Holy Quran.

High-energy ball milling-induced crystallographic structure changes of AZ61-Mg alloy for improved hydrogen storage

The present study investigates the impact of ball milling on the hydrogen storage capabilities of AZ61 magnesium alloys, with a focus on understanding the underlying structure-property relationships. The structure of the hexagonal closed packed (hcp) AZ61 magnesium alloy has been studied through x-ray diffraction analysis, particle size, morphology, and Sievert's analysis. These parameters were used in the study to evaluate the effect of room temperature strain and particle size effect on hydrogen storage. The particle size of the powder samples was found to be anisotropic in all milled samples, with the exception of the as-received sample, which was spherical. The powder morphology changed from spherical to an irregular shape while the particle size decreased from the initial median of 68.33 μm to 15.9 μm for the as-received and sample 2, respectively. When the results of the diffraction peaks were compared to the theoretical positions, a slight shift in angle was observed due to the micro-regulation of metal proportion, which resulted in a change in the lattice structure. The broadening of the peaks observed was attributed to the change in particle size and deformation strain during the milling process. The hcp structure of Mg0.97Zn0.3 phase remained constant, while the size of the crystallites was observed to decrease from 173.3 Å to 22.7 Å. Hydrogen measurements revealed values as high as 5.5 wt% H2 after milling. Diffraction scanning calorimetry study revealed that AZ61 forms MgH2 (major) and AlH3 (minor) phases upon hydrogenation with a desorption activation energy of 188.9 kJ/mol similar to commercial MgH2.

Direct generation of Zn metal using laser-induced ZnS to eradicate carbon emissions from electrolysis Zn production

In response to the goal of net-zero emissions proposed by Intergovernmental Panel on Climate Change, Chinese government has pledged that carbon emissions will peak by 2030, and achieve carbon neutrality by 2060. However, the high carbon energy structure of traditional industries has aggravated environmental problems, such as greenhouse effect and air pollution. The goal of carbon neutrality will be difficult to achieve without the development of disruptive theories and technologies. The electrolytic zinc industry requires high-temperature roasting at ∼1000 °C, generating large amounts of greenhouse gases and SO2. High concentrations of sulfuric acid (200 g/L) are subsequently used for electrolysis, and each ton of zinc produced generates 50 kg of anode slime with lead content of up to 16%, as well as 0.35 m3 of wastewater containing zinc and lead. To solve these problems, an optical metallurgy method is proposed in this study. The proposed method uses laser-induced photoreduction to decompose ZnS and reduce metal ions to metal. Results indicate that Zn0 and S8 can be detected on the surface of ZnS at a specific wavelength and laser fluence. The generation mechanism of Zn0 is such that laser induces an electronic transition that breaks ionic bond in ZnS, resulting in its decomposition and photoreduction to Zn0 under an inert argon gas atmosphere. This method does not reduce other metals in the mineral since it does not use high-temperature roasting, providing a new way of producing high-purity metal without greenhouse gas emissions and heavy metal pollution caused by traditional zinc electrolysis.

Pre-control of shell expansion fracture process by high energy beam

Aiming at the dynamic deformation and fracture response of high-energy precontrolled shell under high strain rate,the expansion and fracture process of 40CrMnSiB steel precontrolled shell was studied by numerical modeling and experiment.The results show that:In detonation loading condition,the high energy beam precontrol shell expansion fracture process can be divided into three stages of free expansion,precontrol fracture and matrix fracture.Firstly, the brittle fracture occurs in the fusion region, and the crack starts at the bottom of the cavity region and propagates along the fusion region to the outer wall of the shell. After the brittle fracture is completed, the adiabatic shear fracture occurs in the matrix, and the normal line between the fracture surface and the inner wall of the fragment is 45 °.The recovered fragment shape is in the shape of precontrolled quadpyramid,and the fragment quality is concentrated in the precontrol area. the fragment dispersion has a good distribution law,which better verifies the pre-control effect of high-energy beam pre-control technology on the fragment shape and the direction of dispersion,and provides technical reference for further optimization of high-energy beam pre-control warhead structure.

High-Energy Lepton Scattering and Nuclear Structure Issues

High-energy lepton scattering constitutes the focus of this study. Developments are provided to motivate the basic choices of kinematic variables for the particular case of semi-inclusive electron scattering where these variables are devised to match well with the underlying dynamics to be expected for the general “nuclear landscape”. Various nuclear structure issues and other issues related to the nature of the electroweak currents at high energies are then discussed, as are some of the issues related to the different conditions occurring for electron scattering versus what is typically the case for charge-changing neutrino reactions.

A novel synthetic sRNA promoting protein overexpression in cell-free systems.

Bacterial small RNAs (sRNAs) that regulate gene expression have been engineered for uses in synthetic biology and metabolic engineering. Here, we designed a novel non-Hfq-dependent sRNA scaffold that uses a modifiable 20 nucleotide antisense binding region to target mRNAs selectively and influence protein expression. The system was developed for regulation of a fluorescent reporter in vivo using Escherichia coli, but the system was found to be more responsive and produced statistically significant results when applied to protein synthesis using in vitro cell-free systems (CFS). Antisense binding sequences were designed to target not only translation initiation regions but various secondary structures in the reporter mRNA. Targeting a high-energy stem loop structure and the 3' end of mRNA yielded protein expression knock-downs that approached 70%. Notably, targeting a low-energy stem structure near a potential RNase E binding site led to a statistically significant 65% increase in protein expression (p < 0.05). These results were not obtainable in vivo, and the underlying mechanism was translated from the reporter system to achieve better than 75% increase in recombinant diaphorase expression in a CFS. It is possible the designs developed here can be applied to improve/regulate expression of other proteins in a CFS.

Single-atom catalysis enabled by high-energy metastable structures.

Owing to limited degrees of freedom, the active sites of stable single-atom catalyst (SAC) often have one structure that is energetically much lower than other local-minimum structures. Thus, the SAC adopts one lowest-energy structure (LES) with an overwhelmingly larger proportion than any other high-energy metastable structure (HEMS), and the LES is commonly assumed to be solely responsible for the catalytic performance of an SAC. Herein, we demonstrate with SACs anchored on CeO2 that the HEMS of an SAC, even though its proportion remains several orders of magnitude lower than the LES throughout the catalytic reaction, can dictate catalysis with extraordinary activity arising from its unique coordination environment and oxidation state. Thus, we unravel the key role of HEMS-enabled catalysis in single-atom catalysis, which shakes the common assumption in the studies of SACs and urges new developments in both experiment and theory to identify and exploit catalysis via HEMSs.

Fabrication of multifunctional WO3.H2O flower-like micro/nanostructures for the oily wastewater treatment

A multifunctional flower-like WO3.H2O coated mesh with superhydrophilic/underwater superoleophobic properties was fabricated for oily wastewater treatment. The XRD and the FESEM analysis demonstrated the orthorhombic phase and flower-like structure of WO3.H2O. The AFM study confirmed the rough surface structure of the mesh. The mesh displayed outstanding superhydrophilic-underwater superoleophobic behavior. The special wettability of flower-like WO3.H2O mesh may be attributed to its intrinsic high surface energy and hierarchical flower-like rough structure. The mesh with the flower-like structure maintained its excellent underwater oil repellency even after many cycles of different mechanical tests. The consistency in underwater superoleophobicity of the flower-like WO3.H2O coated mesh in different pH and saline environments as well as in long-term storage tests demonstrates its excellent chemical and long-term durability. In addition to the separation of oil-water mixtures with lighter and heavier oils, the mesh can also be employed as a primary unit for emulsion separation. Moreover, the flower-like WO3.H2O coated mesh could also remove efficiently the organic contaminant by the synergistic effect of adsorption and photocatalytic activity. These excellent performances enable the mesh to be employed for sustainable oil-water separation in the practical field.

Optimally rejuvenated model binary glasses

Using the creation relaxation algorithm developed for the atomistic modeling of the high-dose irradiation limit of crystalline systems, we explore the limits of the structural rejuvenation of a highly excited model binary glass. This high-energy athermal amorphous structure exhibits a direct transition to homogeneous plastic flow and a microstructure that is largely insensitive to this flow, being characterized by a porous system-spanning network of minimally frustrated structural motifs. The observed homogeneous plasticity is mediated by the same string-like structural excitations, which mediate structural relaxation and microplasticity at finite temperature in more relaxed structures. This highly rejuvenated structural asymptote is not far from the structural state of regions, which have experienced athermal shear localization in more relaxed samples, suggesting an optimally rejuvenated glassy structure will always be limited by that produced by shear localization.

Optimization Simulation of Balanced Distribution of Multimedia Network Modular Teaching Resources

The balanced distribution of multimedia wireless network modular teaching resources is improved by optimizing and adjusting the balanced distribution of multimedia wireless network modular teaching resources. Based on block grid balanced scheduling and resource spectrum fusion, a balanced distribution method of multimedia wireless network modular teaching resources is proposed. A blockchain Internet of Things accesses control network architecture system for the balanced allocation of multimedia wireless network modular teaching resources established using the priority business scheduling method. Modular resource allocation of multimedia wireless networks and adaptive forwarding are adjusted to control the data packets. The bandwidth guarantee mechanism is used for the equitable allocation of multimedia wireless network modular teaching resources information flow. Multi-service hierarchical management of multimedia wireless network modular teaching resources spectrum is controlled by block grid balanced scheduling and resource spectrum fusion. The high-energy physical computing system structure is used to allocate the resource spectrum balance of the modular teaching resources of the multimedia wireless networks, ensuring the bandwidth requirements of various services. The classified management and balanced allocation of the multimedia wireless networks’ teaching storage, system, and teaching spectrum resources are made possible. The results of the tests show that this method effectively reduces the delay in the allocation of modular multimedia wireless network teaching resources, improves the utilization rate of modular multimedia wireless network teaching resources, and significantly improves their reading and writing performance.

Study on Low-Loss and High-Energy Density Coil Structure of a Wireless Power Transmission System Using High Temperature Superconducting Coils for Railway Vehicle

We have been investigating a wireless power transmission (WPT) system using a high-temperature superconducting (HTS) coil for a railway vehicle. In the previous research, we investigated the conceptual design of the WPT system using the HTS coils for the railway vehicle. However, in order to suppress the AC loss per HTS coil below the cooling power of a cryocooler, it was necessary to install multiple HTS coils in parallel on the vehicle and ground sides. Therefore, we investigated the low-loss and high-energy density coil structure in the WPT system for the railway vehicle. In this study, we analyzed the AC loss and the coupling coefficient of various HTS coil structures using the narrow REBaCuO (RE: Rare Earth elements, REBCO) wires in parallel by finite element method (FEM) calculation, and evaluated the power transmission characteristics of the WPT system using the HTS coil structures using the narrow REBCO wires in parallel for the railway vehicle. As a result, we found that the AC loss of the HTS coil structure using the narrow REBCO wires in parallel was lower than that using the wide REBCO wire. The coupling coefficient between coils using a single pancake coil structure was higher than that using a double pancake coil structure. Also, the receiving power density of the WPT system was improved by the HTS coil structures using the narrow REBCO wires. Particularly, the receiving power density of the single pancake coil using the twisted narrow wire in parallel in the coil radial direction increased to about 1.5 times that of the single pancake coil using the wide wire.

Crystal growth and catalytic properties of AgPt and AuPt bimetallic nanostructures under surfactant effect

AgPt and AuPt bimetallic nanostructures offer a highly active catalytic process in acetone hydrogenation reaction to isoproponal. • Sodiumdodecyl sulfate (SDS) promotes anisotropic crystals growth in bimetallic AgPt and AuPt nanostructures. • SDS along with lattice mismatch effects realizes high-energy structure of nanofern in AgPt and large surface area fibrous structure in AuPt. • AgPt and AuPt nanostructures exhibit highly active catalytic properties in acetone hydrogenation reaction. The surface properties of the catalyst, including the surface atom structure and surfactant, determine the charge-transfer process during the catalytic reaction. Here, we present a study on how the surfactants influence the nanocrystal's growth and the catalytic properties of AuPt and AgPt nanoparticles. We found that the surfactant, i.e. sodium dodecyl sulfate (SDS), promotes anisotropic crystal growth in both AuPt and AgPt due to the disruption of symmetrical crystal growth in these fcc crystal and surface passivation processes. Catalytic acetone hydrogenation reaction analysis in the presence of AuPt and AgPt nanocatalyst indicated that the reaction rate was optimized at mild SDS concentration, i.e. 0.1 M, for both AuPt and AgPt nanocatalysts with their turn over frequency of the reaction reached 3363.2 s −1 and 380.2 s −1 , respectively. The AuPt and AgPt nanocatalyst passivated SDS should find extensive use in catalytic hydrogenation reactions.

Ab-initio simulation of the interaction of gold nanoclusters with glycine

Nanomaterial-Biomolecules complexes have several important applications in biological processes and bionanoscience. In this regard, the adsorption of the simplest amino acid (glycine) on the gold nanocluster has been studied to understand the interaction of amino acid with Au nanocluster. Small nanoclusters (neutral and cationic) of five, eight, thirteen, fifteen, and eighteen atoms have been utilized for this study. UV-Vis spectroscopy, Reduced Density Gradient (RDG), HOMO-LUMO analysis has been performed for nanoclusters and their glycine adsorbed complexes which provides information about the charge transfer binding mechanism, and establish the nature of interaction in glycine-gold nanocluster complexes. It is observed that the neutral and cationic Au nanoclusters show the highest adsorption energy for clusters of five, thirteen, and fifteen atoms. When the HOMO-LUMO energy gap of the cationic form of Au nanoclusters and glycine adsorbed Au nanoclusters are studied, it is observed that the HOMO-LUMO energy gap is decreased monotonically as cluster size increases in all cases (namely the lowest energy structure, first higher energy structure, and second higher energy structure). The results from the current work will be applicable as nanocluster sensors for glycine detection.

Resonant inelastic x-ray scattering in Ca3LiOsO6 from first-principles

We have investigated the electronic and magnetic properties of the transition metal oxide (TMO) Ca3LiOsO6 within the density functional theory (DFT) using the generalized gradient approximation while taking into account strong Coulomb correlations (GGA+U) in the framework of the fully relativistic spin-polarized Dirac linear muffin-tin orbital band-structure method. Ca3LiOsO6 is an insulator and forms the K4CdCl6-type crystal structure with relatively high Néel temperature TN = 117 K. Despite of the large strength of spin–orbit coupling, it has only a small effect on the electronic and magnetic properties of Ca3LiOsO6. We have also investigated theoretically the x-ray absorption spectra (XAS), x-ray magnetic circular dichroism (XMCD) and resonant inelastic x-ray scattering (RIXS) spectra at the Os L3 edge. The experimentally measured RIXS spectrum of Ca3LiOsO6 in addition to the elastic scattering peak at 0 eV possesses a sharp feature below 2 eV corresponding to transitions within the Os t2g levels. The excitation located at 4.5 eV is due to t2g→eg transitions. The third wide structure situated at 6–8 eV appears due to ligand-to-metal charge transfer excitations: d−d transitions to the Os t2g manifold from the Os 5dO states derived from the ”tails” of oxygen 2p states. The high energy structure at 10–11.5 eV is due to Os 5dO→eg interband transitions. At higher energy above 11 eV transitions from the Os 5dO states to the empty Ca 5d states are located. We have investigated the effect of SO coupling, Coulomb correlations and core-hole effect on the energy band structure, XAS, XMCD, and RIXS spectra in Ca3LiOsO6.

High-Energy Resolution Fluorescence Detected X-ray Absorption Spectroscopy for the Speciation of Fe in Aerosol Samples

In this study, we compared the high-energy resolution X-ray fluorescence X-ray absorption near-edge structure (HERFD-XANES) and normal XANES spectra of various iron (Fe) species and Fe in atmospheric aerosol samples to explore the advantages of Fe K-edge HERFD-XANES for Fe speciation in aerosols using the linear combination fitting (LCF) of XANES spectra. We also conducted Fe extraction experiments to validate the LCF-XANES. In the HERFD-XANES spectra, the pre-edge region showed specific structures absent in normal XANES. HERFD-XANES also produced more distinctive shoulders within each spectrum than normal XANES. HERFD-XANES was applied to an aerosol sample (MT21-S2) collected in Tokyo, Japan. Normal XANES identified ferrihydrite, biotite, and montmorillonite, whereas HERFD-XANES clearly detected goethite as a fourth component. Normal XANES did not distinguish between ferrihydrite and goethite in LCF because of their similar structures. A similar trend was observed in the pre-edge region, and the Fe extraction experiment result was consistent with the LCF result in the pre-edge region. Thus, LCF of HERFD-XANES, in particular for the pre-edge region, can be a powerful tool for Fe speciation in aerosols.