Partial Structure Research Articles

Development of Neural Network Potentials for Studying Chemical Behaviors of La3+/Nd3+ Ions in Molten LiCl-KCl-CsCl in Combination with Raman Spectroscopy.

The chemistry of molten salts has attracted great research interest owing to their wide applications in diverse fields. In the pyrochemical reprocessing of spent nuclear fuel or molten salt nuclear reactors, lanthanide elements as the principal fission products bring about changes in the composition and properties of molten salts. Herein, we report a comprehensive study on the coordination chemistry of the representative trivalent lanthanide ions (La3+/Nd3+) in LiCl-KCl-CsCl using a multiscale strategy combining Raman spectroscopy, deep learning, and large-scale molecular dynamics (MD) simulations. The neural network potential (NNP)-based MD and Raman spectroscopy studies revealed that La3+/Nd3+ ions prefer to form persistent octahedron complexes with the six-coordinated species as the dominant species at high temperatures. Compared to LaCl63-, NdCl63- shows higher stability with obviously longer lifetimes in LiCl-KCl-CsCl, as confirmed by the observed stronger interaction of Nd3+-Cl- pairs. The total and partial structure factors further indicated the formation of a more stable network structure in LiCl-KCl-CsCl containing NdCl3. Besides, the temperature exerts a larger influence on the local structures of the La3+ species compared to the Nd3+ analogues. According to the potential mean force calculations, the bond dissociation energies follow the order Ln-Cl > Li-Cl > K-Cl > Cs-Cl in LiCl-KCl-CsCl-LnCl3. The NNP-based large-scale MD simulations have been verified to be an efficient and powerful way in molten salt chemistry research.

The First Mean Value Theorem of integral in Perplex Plane

Perplex numbers are an extension of the real numbers, consisting of pairs of real numbers that form a commutative ring. This article considers the partial order structure of perplex numbers and discusses the concept of perplex interval. Based on the definition of integration of perplex functions of perplex variable, this article we investigate the first mean value theorem of integral in perplex plane which can significantly enrich the mathematical toolbox by providing essential methods for estimating and approximating perplex number functions. It also simplifies the solution of complex integral problems involving perplex numbers and fosters theoretical extensions by exploring the behavior of perplex number functions under various conditions. This, in turn, promotes the development of perplex calculus, enhancing the overall theoretical and practical framework of perplex number analysis. In physics, particularly in relativity, studying the first mean value theorem for perplex numbers can provide more precise methods for describing and estimating physical quantities, enhancing the application of hyperbolic numbers in these fields.

Optimizing of partial porous structure for efficient heat transfer and thermal energy storage of phase change material in a rectangular cavity

Optimizing of partial porous structure for efficient heat transfer and thermal energy storage of phase change material in a rectangular cavity

CBS-YOLOv5: fault detection algorithm of electrolyzer plate with low-resolution infrared images based on improved YOLOv5

Abstract In the process of copper electrorefining, accurate detection of electrode plate faults is extremely challenging due to the low resolution of captured infrared images, significant noise interference, and dense electrode plate arrangements. To address these challenges, this paper proposes an improved YOLOv5-based electrode plate fault detection algorithm called CBS-YOLOv5. This algorithm introduces several innovations over the original YOLOv5, including: the incorporation of coordinate attention to enhance the ability of the feature extraction network to separate target information from noise; the construction of a small object detection module to improve the detection of dense small objects by increasing the resolution of the feature map; the replacement of the traditional path aggregation network with a Bi-directional Feature Pyramid Network (BiFPN) for more flexible multi-scale feature fusion; and the integration of the swin transformer to optimize the cross-stage partial bottleneck structure, significantly enhancing the model’s ability to detect densely packed small objects. Experimental results show that the proposed CBS-YOLOv5 model achieves an accuracy of 88.1%, which is an improvement of 5.7% over the base model. Furthermore, this algorithm demonstrates exceptional detection capabilities for dense small objects in low-resolution infrared images while maintaining real-time detection speed, making it suitable for various complex industrial scenarios, including fault detection in non-ferrous metal electrolysis processes. CBS-YOLOv5 not only improves detection accuracy and robustness but also has broad application prospects, offering a new solution for intelligent manufacturing and industrial inspection.

Selective lithium recovery from waste lithium-ion batteries by H2SO4 roasting focused on process intensification and conversion mechanism

The purpose of this study is to prove the feasibility, efficiency and selectivity of lithium recovery from waste lithium-ion batteries (LIB) via sulfuric acid roasting-water leaching by thermodynamic analysis and experimental verification. The feasibility was proved by Gibbs free energy calculations and experiments. Then, the effects of H2SO4 concentration, roasting temperature and roasting time were assessed on the leaching rate of valuable metals. The results indicate that the leaching efficiency of lithium increases firstly and then decreases with the increase of H2SO4 concentration, roasting temperature and roasting time, more than 91 % lithium are leached under optimized experimental conditions: 50 wt% H2SO4, roasting temperature of 650°C, and roasting time of 2 h. Meanwhile, the selectivity of lithium is up to 88 % which means overwhelming majority lithium have been separated completely. In addition, the factors which cause sintering phenomenon such as high temperature and longtime roasting will change the microstructure of roasted product extremely, which is inconducive to the subsequent water leaching. The investigations of the phase conversion mechanism by thermodynamic simulation and instrumental characterization indicated that the leaching behaviors of valuable metals might be influenced by the different reaction pathways of the compounds while changing roasting conditions. The recovery process can be divided into two stages: the partial structure of LiNixCoyMnzO2 was destroyed to form metal sulfates at ambient temperature and the solid phase reaction between unreacted LiNixCoyMnzO2 which contained Li+ in the unstable layered structure with transition metal sulfates at high temperature. The fully reduced low-valence states are mainly (NiO)0.75(MnO)0.25 and CoO, and basically all Li within the crystalline LiNixCoyMnzO2 was de-intercalated and transformed to soluble Li2SO4. These results further confirm the advantages of H2SO4 roasting on selective Li recovery, and provide a better understanding of conversion mechanism by combining theory and experiments.

Aggravation of Cd availability in the plastisphere of paddy soil

Soil plastisphere has attracted many concerns, however, its influence on cadmium (Cd) availability in paddy soil was still unclear. This study carried out batch microcosmic and bagging experiments to explore the influence of microplastic (MPs) on Cd availability in paddy soil under flooding conditions in the view of plastisphere. Results showed that the presence of MPs could act as plastisphere micro-environment. The bacterial community composition changed dramatically around the plastisphere compared with MPs-contaminated bulk soil and control soil. The relative abundance of Symbiobacteraceae, Rhodocyclaceae and Bryobacteraceae was improved in the plastisphere which contributed to the enhanced the reduction of Fe(III) and sulfate in flooding paddy soil. The higher content of Fe(II) and S content contributed to the enrichment of Cd in the plastisphere which aggravated Cd availability in paddy soil under flooding conditions. The partial least squares structure equation modeling results confirmed the presence of MPs in paddy soil could act as plastisphere which could change the bacterial community composition and improve the content Fe and S that was conductive to gather Cd in plastisphere. This study shed lights on the understanding of the role of plastisphere on Cd availability in paddy field ecosystem under flooding conditions.

When affective commitment leads to viability: The role of trust as a mediator and virtuality as a moderator

This study investigates the relationship between affective commitment and team viability, considering team cognitive and affective trust as mediators and the team's level of virtuality as a moderator. A survey-based study was conducted with 177 Portuguese work teams from several companies, and hypotheses were tested through partial least structure equation modelling (PLS-SEM). Our results reveal no statistical evidence of a direct positive association between affective commitment and viability but a significant indirect relationship through cognitive trust. This result highlights the critical role of cognitive trust in promoting viability. Moreover, our findings reveal that virtuality negatively moderates the relationship between affective trust and viability. Although affective trust is positive for viability when virtuality is low, it becomes detrimental when teams present high levels of virtuality. For practice, our results suggest the importance of promoting cognitive trust among teams and the need to be mindful regarding the level of virtuality because it may impact how trust influences team outcomes.

R-Net: Recursive decoder with edge refinement network for salient object detection

Fully convolutional neural (FCN) networks based on encoder-decoder structures are adopted for salient object detection (SOD) and achieve state-of-the-art performance. However, most of the previous works aggregate multilevel features layer by layer and ignore long-range dependencies of spatial context, leading to imbalanced feature processes and context separation. In addition, the blurry edges obtained from previous SOD methods inevitably influence the detection accuracy. To handle these problems, this study proposes an effective recursion-based SOD network R-Net adopting a partial cascade structure, which contains a recursive decoder module (RDM), a long-range dependency module (LRDM), and an edge refinement module (ERM). The RDM is composed of three subdecoders, which can scale different level features to the same size through recursive pooling and recursive upsampling for full-scale feature fusion. The LRDM bridges the encoder and decoder by weighting multilevel features to establish the long-range feature dependency of the spatial context. And the ERM attached to the decoder introduces the shallow reference feature to refine the blurry edges for obtaining delicate detection results. The SOD experimental results on DUTS-TE, HKU-IS, PASCAL-S, ECSSD, and DUT-OMRON datasets demonstrate that the proposed R-Net is more robust under different complex scenes compared with some state-of-the-art methods. The source codes are available at https://github.com/ZEROICEWANG/R-Net.

Compact Aperture-Shared Tri-Frequency Antenna Based on Partial Structure Reutilization for Millimeter-Wave and Sub-6 GHz Applications

Compact Aperture-Shared Tri-Frequency Antenna Based on Partial Structure Reutilization for Millimeter-Wave and Sub-6 GHz Applications

Measurable structure factors of dense dispersions containing polydisperse optically inhomogeneous particles.

Here, it is investigated how optical properties of single scatterers in interacting multi-particle systems influence measurable structure factors. Both particles with linear gradients of their scattering length density and core-shell structures evoke characteristic deviations between the weighted sum 〈S(Q)〉 of partial structure factors in a multi-component system and experimentally accessible measurable structure factors S M(Q). While 〈S(Q)〉 contains only the structural information of self-organizing systems, S M(Q) is additionally influenced by the optical properties of their constituents, resulting in features such as changing amplitudes, additional peaks in the low-wavevector region or splitting of higher-order maxima, which are not related to structural reasons. It is shown that these effects can be systematically categorized according to the qualitative behaviour of the form factor in the Guinier region, which enables assessing the suitability of experimentally obtained structure factors to genuinely represent the microstructure of complex systems free from any particular model assumption. Hence, a careful data analysis regarding size distribution and optical properties of single scatterers is mandatory to avoid a misinterpretation of measurable structure factors.

Coordinate-based simulation of pair distance distribution functions for small and large molecular assemblies: implementation and applications.

X-ray scattering has become a major tool in the structural characterization of nanoscale materials. Thanks to the widely available experimental and computational atomic models, coordinate-based X-ray scattering simulation has played a crucial role in data interpretation in the past two decades. However, simulation of real-space pair distance distribution functions (PDDFs) from small- and wide-angle X-ray scattering, SAXS/WAXS, has been relatively less exploited. This study presents a comparison of PDDF simulation methods, which are applied to molecular structures that range in size from β-cyclo-dextrin [1 kDa molecular weight (MW), 66 non-hydrogen atoms] to the satellite tobacco mosaic virus capsid (1.1 MDa MW, 81 960 non-hydrogen atoms). The results demonstrate the power of interpretation of experimental SAXS/WAXS from the real-space view, particularly by providing a more intuitive method for understanding of partial structure contributions. Furthermore, the computational efficiency of PDDF simulation algorithms makes them attractive as approaches for the analysis of large nanoscale materials and biological assemblies. The simulation methods demonstrated in this article have been implemented in stand-alone software, SolX 3.0, which is available to download from https://12idb.xray.aps.anl.gov/solx.html.

Improving the electrochemical performance of nickel-cobalt organic framework by hybridizing with carbon quantum dots

To improve the electrochemical properties of nickel-cobalt metal-organic skeleton materials, two carbon quantum dots (CQDs), namely, CQD-CA and N-doped CQD-CAn, were prepared by using citric acid as carbon source and then introduced into NiCo-MOF to prepare CQDs/NiCo-MOF composites. Through the application of physical characterization and electrochemical analysis methods, such as SEM, TEM, XRD, XPS and BET, it was found that NiCo-MOF@CA and NiCo-MOF@CAn exhibited a nano thinner lamellar structure, higher specific surface area, larger pore structure, and excellent electron transport ability. Especially, by introducing CQDs, the charge could transfer from oxygen to Ni and Co, and there was some higher electron cloud density around active metals Ni and Co in NiCo-MOF@CAn than in NiCo-MOF, effectively activating the metal center Ni and Co. As the result, the specific capacitance of NiCo-MOF@CAn reached 1917.7 F·g−1 at the potential scan rate 5 mV·s−1, significantly higher than that of NiCo-MOF (1173.4 F·g−1) and NiCo-MOF@CA (1489.3 F·g−1). The method might provide an alternative strategy for modulating the morphology, porous structure and the partial electron structure of the target materials by introducing various CQDs.

Exploring apprentice selection by skilled trade artisans in the Ghanaian construction industry

Purpose This paper aims to investigate the factors influencing trade artisans’ choice of skills selection as apprentice’s trainee in the Ghanaian construction sector and to identify and address the challenges associated with traditional apprenticeship. Trade artisans with technical know-how in construction and general workplace skills from the traditional apprenticeship training (TAT) in the area of construction were selected from selected sites and training centers. Design/methodology/approach This paper adopted the purposive sampling technique with the aim of gathering knowledge from individuals with expertise in the research area, particularly trade craftsmen who have been trained through the TAT system and are directly involved in construction-related works. Partial least square structure equation modelling (PLS-SEM) analytical approach and principal component analysis were used to reduce the dimensionality of the data set and preserve as much information as possible. Findings Three major components, namely, personal and social interest, job assessment and stability and family and faith were identified as the variables that influence an artisan's choice of a skill trade. These influenced the choice of apprenticeship training by young trainees in choosing apprenticeship as a mode of training. Personal interest, living situation of artisans and parents’ educational attainment are the most influencing factors that determine artisans’ choice of selected trades. Moreover, the study also shed light on the challenges inherent in traditional apprenticeship systems, such as the lack of formal technical education, limited access to modern technology and information and poor working conditions. Practical implications The study underscores the imperative for stakeholders to enhance apprenticeship programmes within the construction sector. This involves providing more stable job opportunities, improving working conditions and offering access to modern technology and information. Such enhancements not only attract more young individuals to apprenticeship training but also ensure the sustainability and relevance of the workforce in meeting industry demands. Originality/value The study finally developed a model that could be used as a foundation for future PLS-SEM evaluation and identified the factors that influence the selection of apprenticeship training by trade artisans.

Operational Characteristics of AlGaN/GaN High-Electron-Mobility Transistors with Various Dielectric Passivation Structures for High-Power and High-Frequency Operations: A Simulation Study.

This study investigates the operational characteristics of AlGaN/GaN high-electron-mobility transistors (HEMTs) by employing various passivation materials with different dielectric constants and passivation structures. To ensure the simulation reliability, the parameters were calibrated based on the measured data from the fabricated basic Si3N4 passivation structure of the HEMT. The Si3N4 passivation material was replaced with high-k materials, such as Al2O3 and HfO2, to improve the breakdown voltage. The Al2O3 and HfO2 passivation structures achieved breakdown voltage improvements of 6.62% and 17.45%, respectively, compared to the basic Si3N4 passivation structure. However, the increased parasitic capacitances reduced the cut-off frequency. To mitigate this reduction, the operational characteristics of hybrid and partial passivation structures were analyzed. Compared with the HfO2 passivation structure, the HfO2 partial passivation structure exhibited a 7.6% reduction in breakdown voltage but a substantial 82.76% increase in cut-off frequency. In addition, the HfO2 partial passivation structure exhibited the highest Johnson's figure of merit. Consequently, considering the trade-off relationship between breakdown voltage and frequency characteristics, the HfO2 partial passivation structure emerged as a promising candidate for high-power and high-frequency AlGaN/GaN HEMT applications.

Insights into medicinal attributes of imidazo[1,2-a]pyridine derivatives as anticancer agents.

Cancer ranks among the most life-threatening diseases worldwide and is continuously affecting all age groups. Consequently, many research studies are being carried out to develop new cancer treatments, but many of them experience resistance and cause severe toxicity to the patients. Therefore, there is a continuous need to design novel anticancer agents that are target-based, have a higher potency, and have minimal toxicity. The imidazo[1,2-a]pyridine (IP) pharmacophore has been found to be a prominent moiety in the field of medicinal chemistry due to its vast biological properties. Also, it holds immense potential for combating cancer with minimal side effects, depending on the substitution patterns of the core structure. IPs exhibit significant capability in regulating various cellular pathways, offering possibilities for targeted anticancer effects. The present review summarizes the anticancer profile of numerous IP derivatives synthesized and developed by various researchers from 2016 till now, as inhibitors of phosphoinositide-3-kinase/mammalian target of rapamycin (PI3K/mTOR), protein kinase B/mammalian target of rapamycin (Akt/mTOR), aldehyde dehydrogenase (ALDH), and tubulin polymerization. This review provides a comprehensive analysis of the anticancer activity afforded by the discussed IP compounds, emphasizing the structure-activity-relationships (SARs). The aim is also to underscore the potential therapeutic future of the IP moiety as a potent partial structure for upcoming cancer drug development and to aid researchers in the field of rational drug design.

Genetic and mechanistic evaluation of an individual with para-Bombay phenotype associated with a compound heterozygote comprising two novel FUT1 variants.

As is well documented, the para-Bombay phenotype is typically characterized by the reduction or absence of ABH antigens on red blood cells but the presence of corresponding antigens in saliva. Herein, the underlying molecular mechanism of an individual with para-Bombay AB phenotype combined with two novel variants of the FUT1 gene was investigated. ABH antigens and antibodies were detected in the serum of the proband using conventional serological methods. The coding region nucleotides of the ABO, FUT1, and FUT2 genes were directly sequenced by polymerase chain reaction. Moreover, the FUT1 haploid type in the proband was analyzed by TA clone sequencing. The 3D structure of wild-type and mutant fucosyltransferases were simulated and analyzed using Phyre2 and Pymol software. Lastly, the effect of missense substitution on the function of fucosyltransferase was predicted by the Polymorphism Phenotyping algorithm (PolyPhen-2) and MutationTaster. ABH antigens were noted to be absent on the surface of red blood cells of the proband. The ABO genotype was ABO*A1.02/ABO*B.01, while the FUT2 genotype was FUT2*01/FUT2*c.357T. Interestingly, two novel missense variants (c.289G>A, p.Ala97Thr and c.575G>C, p.Arg192Pro) and one synonymous SNP (c.840G>A) were identified in the FUT1 gene. Furthermore, c.289G>A was detected in one haploid type, whereas c.575G>C and c.840G>A were discovered in another haploid type. Meanwhile, in silico analysis revealed that amino acid substitution caused by missense variants altered the partial spatial structure of the α-helices where residues 97 and 298 were located using 3D homology modeling software. Finally, both missense variants were defined as probably damaging based on PolyPhen-2 prediction. Two novel FUT1 variants were identified in a Chinese individual with para-Bombay AB phenotype, which can expand our understanding of the molecular mechanism underlying the para-Bombay phenotype and contribute to improving the safety of blood transfusion.

A novel dual-band defected ground structure wearable microstrip patch antenna for breast tumor detection in biomedical applications

This paper presents a dual-band, low-profile wearable antenna for detecting breast tumors in biomedical applications. The antenna is designed on the FR4 substrate with an optimized dimension of 32 × 27.5 × 0.61 mm3. The compact rectangular patch is miniaturized by cutting the rectangular slots on the front side. The partial ground structure is used for moving the resonance frequency in the ISM band region and for giving the tripping result of the return loss. A breast phantom is created between the transmitter and receiver for detecting the tumor in the phantom model. The different sizes and positions of the tumor in the breast phantom provide different values of the return loss. The final optimized design of the antenna is operated at 2.43 GHz and 3.32 GHz with −35 and −24 return losses respectively. It has been observed from the simulated and measured results that the antenna has a negligible difference between the reflected coefficient, radiation pattern and gain. Afterward, the antenna is also checked for biocompatibility, which represents its good performance. The on-body analysis of the antenna represents a minor variation in the results. The Specific Absorption Ratio (SAR) value of the antenna is in the acceptable range as defined for the wearable device. It is a promising compact wearable antenna that can be used in biomedical applications.

Rotational spectroscopy and structure of 1,1-dichloro-1-silacyclohex-2-ene

The ground state rotational spectrum of 1,1-dichloro-1-silacyclohex-2-ene has been recorded using a chirped-pulse Fourier transform microwave (CP-FTMW) spectrometer. Several isotopologues in their natural abundances have been observed in the free-jet expansion, and their spectra assigned, making it possible to present a partial heavy-atom substitution structure. Furthermore, the high resolution of this technique allows the complicated hyperfine splitting pattern to be largely deconvoluted. As a result, the on-diagonal nuclear quadrupole coupling constants for the two chlorine atoms have been determined for all observed isotopologues. Additionally, χbc is determined for both chlorine atoms of the parent species. The quadrupole coupling tensors for the parent species have been diagonalised, noting some assumptions have been made pertaining to the off-diagonal nuclear quadrupole coupling constants in the principal axis system, to yield reasonable values of χzz and η which are then compared.

Common Fixed Point Theorems in multiplicative $\mathfrak{m}$-metric space with Applications to the System of Multiplicative Integral Equations and Numerical Results

This paper presents common fixed point results for a pair of self-mappings in multiplicative $\mathfrak{m}$-metric space. Also, we present the multiplicative partial metric structure as a specific case of a multiplicative m-metric space and demonstrate some common fixed point results. To support our conclusions, we present an illustrative example with discontinuous self-mappings. We also provide numerical iterations to approximate the common fixed point and graphs to visually substantiate our findings. As the consequences of our results, we demonstrate several common fixed point results in $m$-metric space and partial metric space. Our findings generalize various fixed point results from the literature. Furthermore, we employ the results to demonstrate the existence and uniqueness of solutions to a system of multiplicative Fredholm integral equations.

Electronic Force Density Fields: Insights into Partial Bonds, Transition States, and Chemical Structure Evolution.

This paper presents the quantum-topological binding approach, in which the electrostatic and total static force density fields, Fes(r) and , together with the electron density gradient field ∇ρ(r), are simultaneously analyzed to elucidate the chemical structure of transition states and the nature of interatomic interactions for semibroken semiformed partial chemical bonds. The approach attributes the discrepancies between the force fields and Fes(r) to the nonclassical electron-electron interaction effects. The internuclear gap between the zero-flux boundaries of Fes(r) and ∇ρ(r) indicates the interatomic charge transfer phenomenon (ICT) that occurs upon the formation of a system from free atoms. Concomitantly, the mismatch of the zero-flux surfaces defined in and ∇ρ(r) can be interpreted as a phenomenon of the electron-transfer-induced quantum chemical response (QCR), which originates from the electron exchange correlation. Our study permits the assertion of parallels between partial bonds and noncovalent interactions, as both typically exhibit incomplete QCRs, indicating the partial electron sharing of the transferred density. The changes in atomic and pseudoatomic charges are employed to describe the evolution of the chemical structure upon the substitution reaction. It is observed that the acquired difference in the actual atomic electronegativity causes polarization upon the heterolytic breaking of virtually nonpolar bonds. It is further proposed that the proximity of closely related stationary states along the reaction path on a potential energy hypersurface implies their similarity in the manifestation of the ICT and sympathetic QCR. Furthermore, the involvement of an electron pair in a partial bond facilitates its delocalization through the attraction by the static forces and Fes(r) to a neighboring nucleus and through the smearing by the Pauli kinetic force FP(r).