Search Results (14,814)

Table tennis racquet blades (TTRBs) are specialized wood materials known for their excellent mechanical properties. As one of the widely used physical vapor deposition technologies, magnetron sputtering has become the most effective method for preparing various thin film materials. In this study, the surface of the TTRB is coated with a Ti film with different thicknesses by magnetron sputtering to improve the performance of the TTRB. The surface roughness, crystal structure, viscoelasticity of the TTRB were analyzed by means of non-contact surface profilometry, X-ray diffraction (XRD), and dynamic mechanical analysis (DMA). In order to effectively test TTRB properties, three types of testing devices were designed, including free-fall rebound, laser vibration measurement, and the dynamic rebound test. The results reveal that the deposition of a Ti film on the surface of the TTRB improves the rigidity and rebound efficiency of the TTRB. Under optimized conditions, the initial amplitude, vertical rebound distance, and rebound rate can reach 2.1 μm, 23.7 cm, 13.7%, respectively, when the deposition thickness is 5 μm. It is anticipated that the modification and the corresponding detection methods developed in this study can foster innovative product development, standardize the TTRB industry, and contribute to the advancement of table tennis. Full article

As a programmable optical device, a liquid crystal optical phased array (LCOPA) has many unique applications. Multi-beam fan-out is one of the novel application cases. However, currently commercially available liquid crystal optical phased array devices typically use reflective structures and are operated on desktop software. This can be inconvenient for the construction of the optical path and the manipulation of the device. On the other hand, multi-beam fan-out capability alone may not be sufficient in some application scenarios. The additional function of focusing might bring some new advantages. Thus, we developed a transmissive liquid crystal optical phased array device based on a fully embedded human–computer interaction control method. It does not require the installation of computer desktop software and only needs a touch screen for easy human–computer interaction. This not only brings convenience to control, but also reduces the cost of devices. Meanwhile, based on the Gerchberg–Saxton algorithm (GS algorithm) and the method of lens phase superposition, we achieved a composite function of multiple-beam fan-out with focusing function by simulation and experiment. This composite function may have unique application value for some special application scenarios. Full article

This study investigated the effects of multiple laser sintering (LS) cycles on a polyamide 12 powder mixture of 70% recycled material and 30% virgin polymer. This research aimed to understand how repeated LS processing influences this specific powder mixture’s thermal and structural properties, which is crucial for optimising its performance in additive manufacturing applications. A thermal analysis revealed significant changes in the thermal behaviour of the powder over successive build cycles. Specifically, there was an observed increase in both the melting temperature and the crystallinity of the powder, alongside a notable decrease in the crystallisation temperature. These alterations suggest that the repeated LS cycles affect the thermal profiles and potentially enhance the material’s stability and usability in additive manufacturing processes. Additionally, a particle size distribution analysis indicated statistically significant differences between the initial and post-sintering states of the powder. These differences are significant as they can influence factors such as flowability and packing density, which are critical for the efficiency of additive manufacturing applications. Microscopic observations further revealed a strong correlation between the crystal morphologies and particle shapes, indicating that the structural changes occurring during processing are inter-related. The relationship underscores the importance of understanding microstructural evolution and the mechanical properties of the final printed products. These findings provide crucial insights into the microstructural evolution and thermal behaviour of recycled PA12 powder during multiple LS processing cycles. This study aids in developing practical strategies for sustainable and efficient powder recycling within the realm of additive manufacturing. By examining the intricate dynamics at play, the research opens avenues for enhancing the performance and environmental sustainability of 3D printing technologies, making them more accessible for various industrial applications. Full article

In this work, a simple hydrothermal method was used to prepare a series of ZnO/r-GO (ZGO-x) catalysts. The obtained products were subjected to a series of characterizations, which showed that the zinc oxide particles were deposited onto r-GO and that the crystal structure was not disrupted. In addition, due to the large specific surface area and the good electrical conductivity of r-GO, more photogenerated electrons can be rapidly transferred from ZnO to r-GO to participate in the reaction, thus improving the photocatalytic performance. The degradation rate of the ZGO-3 sample reached 100% for RhB after simulated sunlight irradiation for 150 min, whereas the pure ZnO degraded RhB by about 83% under the same environment. ZGO-3 also showed the best photocatalytic degradation of methyl orange, with 100% degradation in 180 min, whereas pure ZnO degraded only 87.64% of methyl orange under solar irradiation. Full article

Diaryl ureas (DU) are a cornerstone scaffold in organic and medicinal chemistry, celebrated for their unique structural attributes and broad range of biomedical applications. Their therapeutic reach has broadened beyond kinase inhibition in cancer therapy to encompass diverse mechanisms, including modulation of chromatin remodeling complexes, interference with developmental signaling pathways, and inhibition of stress-activated protein kinases in inflammatory disorders. A critical element in the rational design and optimization of DU-based therapeutics is a detailed understanding of their molecular recognition by target proteins. In this study, we employed a multi-tiered computational approach to investigate the molecular determinants of DU–protein interactions. A large-scale data mining of the Protein Data Bank resulted in an in-house dataset of 158 non-redundant, high-resolution crystal structures of DU–protein complexes. This dataset serves as the basis for a systematic analysis of nonbonded interactions, including hydrogen bonding, salt bridges, π–π stacking, CH-π, cation–π, and XH-π interactions (X = OH, NH, SH). Advanced electronic structure calculations at the B2PLYP/def2-QZVP level are applied to quantify the energetic contributions of these interactions and their roles in molecular recognition of diaryl ureas in their target proteins. The study led to the following findings: central to the molecular recognition of diaryl ureas in proteins are nonbonded π interactions—predominantly CH-π and π–π stacking—that synergize with hydrogen bonding to achieve high binding affinity and specificity. Aromatic R groups in diaryl ureas play a pivotal role by broadening the interaction footprint within hydrophobic protein pockets, enabling energetically favorable and diverse binding modes. Comparative analyses highlight that diaryl ureas with aromatic R groups possess a more extensive and robust interaction profile than those with non-aromatic counterparts, emphasizing the critical importance of nonbonded π interactions in molecular recognition. These findings enhance our understanding of molecular recognition of diaryl ureas in proteins and provide valuable insights for the rational design of diaryl ureas as potent and selective inhibitors of protein kinases and other therapeutically significant proteins. Full article

Lithium niobate (LiNbO₃) has remarkable ferroelectric properties, and its unique crystal structure allows it to undergo significant spontaneous polarization. Lithium niobate plays an important role in the fields of electro-optic modulation, sensing and acoustics due to its excellent electro-optic and piezoelectric properties. Thin-film LiNbO₃ (TFLN) has attracted much attention due to its unique physical properties, stable properties and easy processing. This review introduces several main preparation methods for TFLN, including chemical vapor deposition (CVD), molecular beam epitaxy (MBE), pulsed laser deposition (PLD), magnetron sputtering and Smartcut technology. The development of TFLN devices, especially the recent research on sensors, memories, optical waveguides and EO modulators, is introduced. With the continuous advancement of manufacturing technology and integration technology, TFLN devices are expected to occupy a more important position in future photonic integrated circuits. Full article

Characteristics of electrodeposited tungsten coatings prepared at 1193 K and varying current density were investigated. The crystal structure and microstructure of tungsten coatings were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and photoelectron spectroscopy (XPS). The results indicated that pulsed current density significantly influence the tungsten nucleation and electro-crystallization phenomena. The average grain size of the coating becomes larger with increasing current density, which demonstrates that appropriate high cathodic current density can accelerate the growth of grains on the surface of the substrate. The micro-hardness of tungsten coatings increases with increasing thickness and then slightly decreases; the maximum micro-hardness is 589.55 HV, with the oxygen content remaining below 0.03 wt%. Full article

Phase change memory (PCM) technology demonstrates significant potential as a next-generation non-volatile storage solution for information applications. Ge₂Sb₂Te₅ (GST) alloy, the most well-established material employed in commercial PCM devices, exhibits limited thermal stability. Doping, as an effective approach for enhancing thermal stability, often induces element segregation and phase separation. This study systematically investigates the impact of indium (In) doping on GST phase-change material. Experimental results demonstrate that In doping significantly enhances the thermal stability of GST film. In17GST exhibits a 130 °C increase in crystallization temperature (from 181 °C to 311 °C). Especially, the introduction of In leads to the formation of In₂Te₃ phase, which exhibits a remarkably similar crystal structure to GST with only a ~2% lattice mismatch. Consequently, In₂Te₃ phase forms a coherent structure with GST lattice, thereby promoting the stability of the phase boundary. Additionally, In₂Te₃ phase facilitates efficient heating with a 5.7% improvement in heating efficiency (913 K vs. 864 K at 5 ns) and contributes to improved RESET operations in PCM devices. Our study lays the foundation for the composition and structure design for high thermal stability and low power consumption in PCM devices. Full article

This study reports the synthesis and characterization of a novel thiolate-bridged heteroleptic dinuclear silver(I) complex, [Ag(μ-C₆F₅S)(dppbz)]₂, incorporating o-bis(diphenylphosphino)benzene (dppbz). The complex was synthesized in high yield via the reaction of silver(I) oxide with pentafluorothiophenol and dppbz. Single crystal X-ray diffraction analysis revealed a distorted tetrahedral structure with an Ag₂S₂ core, where each Ag atom is coordinated by dppbz. The Ag…Ag distance (3.2652(3) Å) suggests weak argentophilic interaction. Notably, an uncommon intermolecular fluorine-fluorine contact is observed, likely stabilized by intermolecular hydrogen bonding stabilizing the structure. The complex shows weak luminescence under UV radiation with an emission maximum at 514 nm. Full article

This research is on the structural, optical, and electrical properties of SnO₂ and ZnO thin films, which are increasingly used in many electronic devices, including gas sensors, light-emitting diodes, and solar cells. For the various applications, it is essential to accurately determine the band gap energy, as it controls the optical and electrical behavior of the material. However, there is no single method for its determination; rather, different approximations depend on the crystalline quality and the doping level because these modify the energy band structure of the semiconductor. With the aim of analyzing the various approaches, SnO₂ and ZnO films were prepared by sputtering on unheated glass substrates and subsequently annealed in N₂ at various temperatures between 250 °C and 450 °C. These samples showed different crystallite sizes, absorption coefficients, and free carrier concentrations depending on the material and the annealing temperature. Analysis of the results shows that the expression developed for amorphous materials underestimates the band gap value, and the so-called unified method tends to overestimate it, while the equations for perfect or heavily doped crystals give band gap energies more consistent with the doping level, regardless of the crystalline quality of the films. Full article

This study evaluates the perfection of the crystal structure of single-crystal turbine blade castings made from the CMSX-4 nickel superalloy. The analysis included primary and secondary crystal orientation measurements using the Ω-scan method and the novel OD-EFG X-ray diffractometer. The selected microstructural parameters of the single crystals were also analyzed, including the assessment of stereological parameters and the degree of porosity. A creep test was performed according to standard procedures and under conditions simulating real operational environments. The model single-crystal turbine blades were manufactured using the Bridgman–Stockbarger method, with variable withdrawal rates of 1 and 3 mm/min. Heat treatment of the single-crystal castings involved solution treatment followed by double aging. The evaluation of structural perfection was carried out in three states: as-cast, after solution heat treatment, and after double aging. The crystallographic orientation of the blades was determined on both the airfoil and the root part. The study determined how crystallographic orientation and microstructural parameters influence the creep resistance of the castings. It was found that in the as-cast condition, the greatest influence on high creep strength has a small deviation of the primary and constant value of secondary crystal orientation along the height of the blade casting. After heat treatment, the highest creep resistance was obtained for the blade manufactured at a withdrawal rate at 1 mm/min. Full article

The trapiche garnet, a gemstone of unparalleled beauty, boasts a rare structure comprising one core, six radiating arms, and a main body. The occurrence of garnet within the trapiche structure elevates it beyond the species, granting it significant scientific and gemological value. In this study, we conducted the first systematic investigation of trapiche garnets from the Chun’an area, Zhejiang Province, China. These samples were proven grossular through the analysis of spectroscopy and major elements. The trace element features are consistent with the distribution patterns of garnet in hydrothermal metasomatic skarn. Microscopic observation and Raman spectroscopy revealed that dark inclusions within the core and arms consist predominantly of amorphous carbon. The in situ U-Pb dating of the trapiche garnets revealed a crystallization age of 120.7 ± 4.7 Ma, corresponding to the late Yanshanian movement. It is speculated that the contact metasomatism between magma enriched in Al and surrounding rock led to the formation of calcareous skarn. This study provides insights into gemological, geochemical, and chronological characteristics, broadening the research on trapiche structures, and enhancing the understanding of gemstone mineralization timing and local tectonic activity. Full article

A continuous flow process was optimised for the perchlorination of p-cresol to the corresponding 2,4,6-trichloro-cyclohexa-2,5-dienone derivative employing trichloroisocyanuric acid as a green and safer-to-handle chlorinating agent. The system could furnish 200 g of pure material within 5 h of operation (throughput = 40 g h⁻¹). The compound was easily isolated by filtration and obtained in 95% purity as determined by GC analysis; it could be further purified by crystallisation from a 20:1 Hexane/AcOEt mixture left at −20 °C overnight. The resultant product was characterised by ¹H & ¹³C NMR, MS, IR analyses, with melting point and X-ray single-crystal data being obtained, confirming the structure. Full article

Despite notable advancements in the development of borate materials, improving their luminescent efficiency remains an important focus in materials research. The synthesis of lanthanum borates (LaBO₃), doped and co-doped with europium (Eu³⁺) and dysprosium (Dy³⁺), by the solid-state method, has demonstrated significant potential to address this challenge due to their unique optical properties. These materials facilitate efficient energy transfer from UV-excited host crystals to trivalent rare-earth activators, resulting in stable and high-intensity luminescence. To better understand their structural and vibrational characteristics, Fourier transform infrared (FTIR) spectroscopy and Raman spectroscopy were employed to identify functional groups and molecular vibrations in the synthesized materials. Additionally, X-ray diffraction (XRD) analysis was conducted to determine the crystalline structure and phase composition of the samples. All observed transitions of Eu³⁺ and Dy³⁺ in the excitation and emission spectra were systematically analyzed and identified, providing a comprehensive understanding of their behavior. Although smartphone cameras exhibit non-uniform spectral responses, their integration into this study highlights distinct advantages, including contactless interrogation, effective UV excitation suppression, and real-time spectral analysis. These capabilities enable practical and portable fluorescence sensing solutions for applications in healthcare, environmental monitoring, and food safety. By combining advanced photonic materials with accessible smartphone technology, this work demonstrates a novel approach for developing low-cost, scalable, and innovative sensing platforms that address modern technological demands. Full article

Microbial-induced carbonate precipitation (MICP) is an eco-friendly soil stabilization technique. This study explores the synergistic effects of incorporating hydroxypropyl methylcellulose (HPMC) into the MICP process to enhance the disintegration and seepage resistance of loess. A series of disintegration, seepage, scanning electron microscopy (SEM), and mercury intrusion porosimetry (MIP) tests were conducted. The results show that HPMC forms protective membranes around calcium carbonate crystals produced by MICP and soil aggregates, which enhance cementation, reduce soluble salt dissolution, promote soil particle aggregation, and seal pore structures. At the optimal 0.4% HPMC dosage, the maximum accumulative disintegration percentage and the disintegration velocity decreased to zero. Additionally, HPMC-modified MICP reduced the amount, size, and flow velocity of seepage channels in loess. The integration of MICP with HPMC provides an efficient and sustainable solution for mitigating loess disintegration and seepage issues. Full article