Additive Channel Research Articles

Biomimetic and electrostatic self-assembled nanocellulose/MXene films constructed with sequential bridging strategy for flexible supercapacitor

Despite the two-dimensional titanium carbide MXene (Ti3C2Tx) has shown promising applications in energy storage, the inherent self-stacking and weak connectivity among nanosheets present a challenge in manufacturing robust MXene films for emerging flexible supercapacitors. Herein, inspired by the robust “soft-hard” structured exoskeletons of crustaceans, the biomimetic cellulose nanofibers (CNFs)/MXene-Al (CM-Al) film with integrated high mechanical toughness, electroconductivity and electrochemical behavior, sequential bridging with hydrogen and ionic bonds, is crafted via the facile electrostatic self-assembly strategy. The embedded CNFs guide the in-plane orientation of MXene through hydrogen bonding, forming a “soft-hard” microstructure and dramatically enhancing the mechanical toughness of CM-Al. The rigid ionic bonds established between the oxygen-containing groups on CNFs and MXene with Al3+ further elevate the mechanical strength (163.88 MPa) and act as additional electron transfer channels to impart the reinforced electroconductivity (82.63 S cm−1). Benefiting from the more active site exposure induced by the expanded MXene layer spacing after CNFs embedding and the weakened intrinsic resistance caused by the constructed ionic bonding, the assembled flexible quasi-solid-state symmetric supercapacitor with CM-Al as electrode delivers a high area capacitance (679 mF cm−2), energy density (16.2 μWh cm−2), cycling capability (85.3 % capacitance retention after 10,000 cycles) and intrinsic tolerance to various non-stretching deformations. Moreover, the selective principles for metal ions are summarized that involved a comprehensive consideration of ionic radius, charge density and basic chemical properties. This work demonstrates an accessible and feasible construction strategy for flexible composite films and provides an alternative pathway for wearable energy storage devices.

Designing a three-dimensional CoFe2O4 cross-frame wrapped with carbon nanotubes for monitoring the environmental pollutant nitrobenzene

In this study, we employ a catalytic system derived from a zeolitic imidazolate framework (ZIF), comprising carbon nanotube-wrapped CoFe2O4 with a modified 3D cross morphology. The seamless transition between ionic valence states in CoFe2O4 contributes to enhanced material conductivity, illustrating a significant synergistic coupling effect. The 3D matrix has the capacity to generate a greater number of active sites and exhibit a high surface area. The generation of nanotubes provides additional channels for electron transport, thereby improving the charge transfer efficiency and enhancing the electrochemical sensing capability of the system. The synthesized material demonstrates outstanding electrochemical sensing capabilities for nitrobenzene, exhibiting impressive sensitivity with a remarkably low limit of detection at 0.013 μM and a broad linear response range (0.06–414.9 μM), heightened sensitivity, excellent repeatability, and superior selectivity. Furthermore, the quantification of trace nitrobenzene in water samples demonstrates a recovery rate within the range of 96.0 %–102.8 %. Consequently, this material presents itself as a promising catalyst for electrochemical analysis and introduces a novel approach for detecting low concentrations of nitrobenzene.

Ultraviolet-cured heat-resistant and stretchable gel polymer electrolytes for flexible and safe semi-solid lithium-ion batteries

Lithium-ion (Li-ion) batteries assembled with gel polymer electrolytes (GPEs) are predicted to increase battery energy density while maintaining battery safety. In this work, poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) is successfully used as a polymer matrix to prepare a new kind of GPE (PHHNT) by ultraviolet (UV) curing technology. The polymer network structure formed by photopolymerization technology significantly enhances the tensile properties of the electrolyte. Lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) improves the concentration and transport efficiency of lithium ions in the electrolyte as well as the ionic conductivity (1.22 × 10−3 S cm−1) of the GPEs. In addition, the unique tubular structure of the halloysite nanotube (HNT) and the opposite charges carried by the inner and outer surfaces provide additional channels for the lithium salt and facilitate its dissociation. This enhances the expedited movement of Li+ inside the electrolyte, while simultaneously improving the electrochemical and thermal durability of the electrolyte. The assembled LiFePO4 (LFP)/PHHNT/Li battery has an initial discharge-specific capacity of 140.5 mAhg−1 at a current density of 0.5C, showing a high capacity retention rate of 89 % after 120 cycles. The design of this composite material significantly improves the overall performance of the electrolyte and is more suitable for flexible and safe solid-state Li-ion batteries.

The metamorphosis of external vulnerability from ‘original sin’ to ‘original sin redux’: currency hierarchy and financial globalization in emerging economies

How has financial globalization changed the nature of external vulnerability of emerging economies? To answer this question, we first present an overview of the changes in international capital flows and cross-border stocks involving emerging economies from the 1970s to the COVID-19 crisis and then identify relevant recent shifts in financial globalization. We adapt the concept of currency hierarchy to the most recent features of financial globalization. We deploy a stylized balance sheet analysis to better understand the metamorphosis of these economies’ vulnerabilities. We find the occurrence of the phenomenon of ‘original sin’ during financial internationalization. In contrast, in more recent times of financial globalization, the diversification of financial flows and investors and the increase of securities denominated in domestic currency have created additional channels of vulnerability, labeled as ‘original sin redux’. We find that the private sector in Southern economies is mostly exposed to these new vulnerabilities. At first sight, it is good news because it preserves the fiscal space of Southern States in the case of capital outflows. However, it might create new contingent liabilities for the public sector. We call for capital account regulation in a broad sense to target these new complex vulnerabilities.

Merging mechanical bound states in the continuum in high-aspect-ratio phononic crystal gratings

Mechanical bound states in the continuum (BICs) present an alternative avenue for developing high-frequency, high-Q mechanical resonators, distinct from the conventional band structure engineering method. While symmetry-protected mechanical BICs have been realized in phononic crystals, the observation of accidental mechanical BICs—whose existence is independent of mode symmetry and tunable by structural parameters—has remained elusive. This challenge is primarily attributed to the additional radiation channel introduced by the longitudinal component of elastic waves. Here, we employ a coupled wave theory to predict and experimentally demonstrate mechanical accidental BICs within a high-aspect-ratio gallium arsenide phononic crystal grating. We observe the merging process of accidental BICs with symmetry-protected BICs, resulting in reduced acoustic radiation losses compared to isolated BICs. This finding opens up new possibilities for phonon trapping using BIC-based systems, with potential applications in sensing, transduction, and quantum measurements.

Effect of deformation twinning on the early oxidation behaviour of 316L steel exposed to liquid lead-bismuth eutectic

Twins were introduced into 316L austenitic stainless steel by shot peening treatments. The twinned 316L was then exposed along with pristine 316L to oxygen-saturated liquid lead-bismuth eutectic at 550 °C for 120 h. We observed that the inner oxide layer on the pristine 316L consisted of Fe–Cr spinel and reticulated nickel-rich phases, whereas that on the twinned 316L consisted of Fe–Cr spinel and Cr2O3 without the nickel-rich phases. The factor contributing to the different microstructure and composition of the oxide layer on pristine and twinned 316L is that the twin boundaries provide additional channels for Cr diffusion into the oxide front, allowing the formation of Cr2O3 and high Cr dense Fe–Cr spinel. As a result, the Ni rich phases do not have sufficient space to exist and are pushed back into the Cr poor steel matrix.

An image encryption scheme without additional key transmission based on an N-dimensional closed-loop coupled triangular wave model

Currently, many image encryption schemes either require additional secure channels for key transmission or employ a key that exhibits a lack of correlation with the plaintext, thereby reducing the security of the algorithm. This study proposes a novel image encryption scheme to address this issue. A new N-dimensional closed-loop coupled triangular wave model is developed to overcome the limitations of the sine function in chaotic systems while reducing the difficulty of the chaotic system design. Experimental analysis demonstrates that the generated chaotic systems exhibit complex chaotic behaviors and outperform other chaotic systems designed using the sine function. Specifically, we utilize difference extension technology to embed key information into the plaintext image and design a scrambling and diffusion algorithm based on Latin rectangles to encrypt the remaining pixel matrix without key information. Finally, the pixel matrix containing the key information is concealed to obtain the final ciphertext image. Simulation analysis and security evaluation demonstrate that the proposed algorithm outperforms the encryption performance and security of several advanced image encryption algorithms.

The effects of back-projection variants in BPF-like TOF PET reconstruction using CNN filtration - Based on simulated and clinical brain data.

The back-projection strategies such as confidence weighting (CW) and most likely annihilation position (MLAP) have been adopted into back-projection-and-filtering-like (BPF-like) deep reconstruction model and shown great potential on fast and accurate PET reconstruction. Although the two methods degenerate to an identical model at the time resolution of 0ps, they represent two distinct approaches at the realistic time resolutions of current commercial systems. There is a lack of a systematic and fair assessment on these differences. This work aims to analyze the impact of back-projection variants on CNN-based PET image reconstruction to find the most effective back-projection model, and ultimately contribute to accurate PET reconstruction. Different back-projection strategies (CW and MLAP) and different angular view processing methods (view-summed and view-grouped) were considered, leading to the comparison of four back-projection variants integrated with the same CNN filtration model. Meanwhile, we investigated two strategies of physical effect compensation, either introducing pre-corrected data as the input or adding a channel of attenuation map to the CNN model. After training models separately on Monte-Carlo-simulated BrainWeb phantoms with full dose (events=3×107), we tested them on both simulated phantoms and clinical brain scans with two dosage levels. For the performance assessment, peak signal-to-noise ratio (PSNR) and root mean square error (RMSE) were used to evaluate the pixel-wise error, structural similarity index (SSIM) to evaluate the structural similarity, and contrast recovery coefficient (CRC) in manually selected ROI to compare the region recovery. Compared to two MLAP-based histo-image reconstruction models, two CW-based back-projected image methods produced clearer, sharper, and more detailed images, from both simulated and clinical data. For angular view processing methods, view-grouped histo-image improved image quality, while view-grouped cwbp-image showed no advantage except for contrast recovery. Quantitative analysis on simulated data demonstrated that the view-summed cwbp-image model achieved the best PSNR, RMSE, SSIM, while the 8-view cwbp-image model achieved the best CRC in lesions and the white matter. Additionally, the multi-channel input model including the back-projection image and attenuation map was proved to be the most efficient and simplest method for compensating for physical effects for brain data. Applying Gaussian blur to the histo-image yielded images with limited improvement. All above results hold for both the half-dose and the full-dose cases. For brain imaging, the evaluation based on metrics PSNR, RMSE, SSIM, and CRC indicates that the view-summed CW-based back-projection variant is the most effective input for the BPF-like reconstruction model using CNN filtration, which can involve the attenuation map through an additional channel to effectively compensate for physical effects.

Engineering the luminescence and photothermal properties of metal complex Ruphen functionalized with silver nanoparticles for infrared human detection

A luminescence quenching enhanced infrared (IR) detector has been developed to achieve highly sensitive recognition of human body by adding metallic luminescence quenchers. Spherical Ag NPs were mixed with Ru(phen)32+ complex to obtain temperature-sensitive Ag/Ruphen/PVDF films. The relationships among luminescence output, temperature rise and silver addition were investigated and a satisfactory combination of enhanced luminescence factor and temperature change was found with an addition of 5 mol% of 71 nm Ag NPs. It is found that the metal-enhanced luminescence output is insignificant compared to its thermal ingredient since silver provides additional possible electron transfer channels, promoting non-radiative transitions and weakening luminescence. Besides, the Ag NPs induced additional temperature rise bringing further reduction of luminescence. The photothermal effect of Ag NPs can attain a higher temperature change under a certain IR radiation without an observed degradation of luminescence output. A coupled optical-thermal model was established to explain the schematic of the constructed infrared thermal detector. The non-invasive detections of moving and stationary human by the detector were successfully demonstrated. The work tends to provide an engineered optical-thermal model in luminophores and construct highly sensitive luminescence-based infrared thermal detectors.

Deep learning for 4D modeling of glioblastoma multiforme with tumor treating fields (TTFields) therapy.

e14032 Background: Prediction of future tumor growth and recurrence are critical in the management of patients with glioblastoma multiforme (GBM). This study develops a deep learning method for estimating future areas of GBM spread across multiple timepoints using MRI in patients receiving tumor treating fields (TTFields) therapy. Methods: A single institutional database was queried to identify adult patients with histologically confirmed newly diagnosed and/or recurrent GBM undergoing TTFields therapy. For newly diagnosed GBM, patients received TTFields with temozolomide after maximal debulking surgery and chemoradiation therapy. For recurrent GBM, patients received TTFields as monotherapy. For each patient, all serial follow-up MRI exams were obtained, including T1 (pre-/post-contrast), T2, and T2/FLAIR sequences. On each exam, all regions of enhancing tumor core (excluding peritumoral edema, necrotic core, or resection cavity) were delineated and aligned across time points using nonlinear deformable registration. For any given pair of serial exams, a convolutional neural network (CNN) was designed to predict future GBM tumor on the follow-up exam given the precursor exam and time interval between the studies. The model is implemented as a 3D encoder-decoder architecture yielding a dense per-voxel prediction of future tumor probability optimized using a binary cross-entropy loss function. Class weights were used to develop high sensitivity and high positive predictive value (PPV) model variants. To generate final logit scores, time information is concatenated to the penultimate feature map as an additional feature channel, allowing the model to calibrate each estimate based on elapsed time between any pair of exams. Upon convergence, a 4D learned representation allows for prediction of spatial distribution of GBM tumor at any future time point. Results: A total of 123 patients (1112 total MR exams) were identified. For any given single patient, a median of 6 follow-up exams (IQR 2.5-12.5) at a median interval follow-up time of 46 days (IQR 15.75-63 days) between exams was observed. Upon five-fold cross-validation, the model demonstrated a 0.44 Dice score overlap between predicted and true areas of future GBM tumor growth. The high sensitivity model yielded a per-voxel sensitivity of 0.91 (IQR 0.77-0.99) and PPV of 0.26 (IQR 0.17 to 0.32), while the high PPV model yielded a per-voxel sensitivity of 0.14 (IQR 0.00 to 0.46) and PPV of 0.75 (IQR 0.56 to 0.94). Upon visual confirmation, model predictions across incremental time values for any given exam yielded expected gradual growth of tumor over time. Conclusions: A deep learning model can accurately predict future areas of GBM tumor growth in patients receiving TTFields therapy, with optimal performance that may be calibrated for high sensitivity or high PPV based on clinical use case.

Breakdown of steady-state superradiance in extended driven atomic arrays

Recent advances in generating well controlled dense arrangements of individual atoms in free space have generated interest in understanding how the extended nature of these systems influences superradiance phenomena. Here, we provide an in-depth analysis on how space-dependent light shifts and decay rates induced by dipole-dipole interactions modify the steady-state properties of coherently driven arrays of quantum emitters. We characterize the steady-state phase diagram, with particular focus on the radiative properties in the steady state. Interestingly, we find that diverging from the well-established Dicke paradigm of equal all-to-all interactions significantly modifies the emission properties. In particular, the prominent quadratic scaling of the radiated light intensity with particle number in the steady state—a hallmark of steady-state Dicke superradiance—is entirely suppressed, resulting in only linear scaling with particle number. We show that this breakdown of steady-state superradiance occurs due to the emergence of additional dissipation channels that populate not only superradiant states but also subradiant ones. The additional contribution of subradiant dark states in the dynamics leads to a divergence in the time scales needed to achieve steady states. Building on this, we further show that measurements taken at finite times for extended atom ensembles reveal properties closely mirroring the idealized Dicke scenario. Published by the American Physical Society 2024

Low Temperature (Down to 6 K) and Quantum Transport Characteristics of Stacked Nanosheet Transistors with a High-K/Metal Gate-Last Process.

Silicon qubits based on specific SOI FinFETs and nanowire (NW) transistors have demonstrated promising quantum properties and the potential application of advanced Si CMOS devices for future quantum computing. In this paper, for the first time, the quantum transport characteristics for the next-generation transistor structure of a stack nanosheet (NS) FET and the innovative structure of a fishbone FET are explored. Clear structures are observed by TEM, and their low-temperature characteristics are also measured down to 6 K. Consistent with theoretical predictions, greatly enhanced switching behavior characterized by the reduction of off-state leakage current by one order of magnitude at 6 K and a linear decrease in the threshold voltage with decreasing temperature is observed. A quantum ballistic transport, particularly notable at shorter gate lengths and lower temperatures, is also observed, as well as an additional bias of about 1.3 mV at zero bias due to the asymmetric barrier. Additionally, fishbone FETs, produced by the incomplete nanosheet release in NSFETs, exhibit similar electrical characteristics but with degraded quantum transport due to additional SiGe channels. These can be improved by adjusting the ratio of the channel cross-sectional areas to match the dielectric constants.

An Innovative Approach to the Organization of the Company's Activities Based on the Use of Digital Technologies for Brand Promotion

The relevance of the research is determined by the need to adapt the activities of enterprises to the rapidly developing digital environment, which requires regular revision of the promotion strategy and adaptation to the new changing conditions shaping the business landscape. The purpose of the study is to develop an innovative approach to the organization of the company's activities based on the use of digital technologies for brand promotion in the face of changes, as well as to determine the directions of their practical implementation.The objectives of the research are to determine the theoretical and methodological foundations for the formation and implementation of a brand promotion strategy in the company's activities; substantiate the role of digital technologies in the brand promotion strategy of a modern enterprise; develop an innovative approach to the organization of the company's activities based on the use of digital brand promotion technologies.Methodology. The paper uses the method of theoretical analysis, the method of classification, synthesis, deduction and induction. The following practical research methods are used: observation method, analysis of collected data, description, economic analysis, comparison method, systematic approach. The applied empirical research methods include: choosing a platform for posting content, ways and channels of influencing the consumer audience of an Internet resource. The results. The elements of an innovative approach to the organization of an enterprise's activities based on the use of digital brand promotion technologies are revealed: the procedure for analyzing content and determining its compliance with the target audience; segments of the target audience for interaction in the process of brand promotion; main and additional promotion channels; options for creating a communication strategy; metrics used to assess the effectiveness of a brand promotion strategy. The stages of digital content creation are highlighted and the author's recommendations for their improvement are proposed.Conclusions. An innovative approach to brand promotion using digital promotion technologies is presented, the uniqueness of which consists in the use of updated basic elements and digital tools at each stage of the strategy, allowing to increase the adaptability of the enterprise to changing environmental conditions.

Hidden social complexity behind vocal and acoustic communication in non-avian reptiles.

Social interactions are inevitable in the lives of most animals, since most essential behaviours require interaction with conspecifics, such as mating and competing for resources. Non-avian reptiles are typically viewed as solitary animals that predominantly use their vision and olfaction to communicate with conspecifics. Nevertheless, in recent years, evidence is mounting that some reptiles can produce sounds and have the potential for acoustic communication. Reptiles that can produce sound have an additional communicative channel (in addition to visual/olfactory channels), which could suggest they have a higher communicative complexity, the evolution of which is assumed to be driven by the need of social interactions. Thus, acoustic reptiles may provide an opportunity to unveil the true social complexity of reptiles that are usually thought of as solitary. This review aims to reveal the hidden social interactions behind the use of sounds in non-avian reptiles. Our review suggests that the potential of vocal and acoustic communication and the complexity of social interactions may be underestimated in non-avian reptiles, and that acoustic reptiles may provide a great opportunity to uncover the coevolution between sociality and communication in non-avian reptiles. This article is part of the theme issue 'The power of sound: unravelling how acoustic communication shapes group dynamics'.

Multi-scale revealing how real catalyst layer interfaces dominate the local oxygen transport resistance in ultra-low platinum PEMFC

In view of a catalyst layer (CL) with low-Pt causing higher local transport resistance of O2 (Rlocal), we propose a multi-study methodology that combines CO poisoning, the limiting current density method, and electrochemical impedance spectroscopy to reveal how real CL interfaces dominate Rlocal. Experimental results indicate that the ionomer is not evenly distributed on the catalyst surface, and the uniformity of ionomer distribution does not show a positive correlation with the ionomer content. When the ionomer coverage on the supported catalyst surface is below 20 %, the ECSA is only 10 m2·g−1, and the ionomer coverage on the supported catalyst surface reaches 60 %, the ECSA is close to 40 m2·g−1. The ECSA has a positive correlation with ionomer coverage. Because the ECSA is measured by CO poisoning, it can be inferred that the platinum contacted with ionomer can generate effective active sites. Furthermore, a more uniform distribution of ionomer can create additional proton transport channels and reduce the distance for oxygen transport from the catalyst layer bulk to the active sites. A higher ECSA and a shorter distance for oxygen transport will reduce the Rlocal, leading to better performance.

Enhanced ethanol dehydration performance of cationic COFs filled anionic alginate hybrid membranes

Adding charged fillers to incorporate long-range electrostatic interactions is an effective way to reduce structure defects and improve separation performance of polyelectrolyte membranes. In this study, three cationic covalent organic frameworks (COFs), TpEB, TpTGCl, and TpPy, were incorporated into anionic alginate to prepare hybrid membranes for pervaporation dehydration of ethanol. With the increase of electrostatic interaction, the decrease in the mobility of polymer chains leads to an increase in the crystallinity and selectivity. Meanwhile, the inherent hydrophilic channels of iCOFs provided additional mass transfer channels, increasing the membrane permeability. When separating a 90 wt% ethanol/water mixture at 76 °C, the hybrid membrane containing 15 wt% TpEB exhibited the highest separation performance with a permeation flux of 2460 g m-2 h-1 and a separation factor of 2110, and it also demonstrated ideal long-term stability. This work provides a new perspective for the selection of fillers in the design process of hybrid membranes in the future.

Superconducting quantum memory with a suspended coaxial resonator

A promising way to store quantum information is by encoding it in the bosonic excitations of microwave resonators. This provides for long coherence times, low dephasing rates, as well as a hardware-efficient approach to quantum error correction. There are two main methods used to make superconducting microwave resonators: by traditionally machining them out of bulk material and by lithographically fabricating them on a chip in thin film. 3D resonators have few loss channels and larger mode volumes, and therefore smaller participations in the lossy parts, but it can be challenging to achieve high material quality. On-chip resonators can use low-loss thin films, but they confine the field more tightly, resulting in higher participations and additional loss channels from the dielectric substrate. In this work, we present a design in which a dielectric scaffold supports a thin-film conductor within a 3D package, thus combining the low surface participations of bulk-machined cavities with high quality and control over materials of thin-film circuits. By incorporating a separate chip containing a transmon qubit, we realize a quantum memory and measure single-photon lifetimes in excess of a millisecond. This hybrid 3D architecture has several advantages for scaling as it relaxes the importance of the package and permits modular construction with separately replaceable qubit and resonator devices.

COMPARATIVE STUDY OF THE ISLAMISATION PROCESS IN MALAYSIA AND NIGERIA: A SOCIAL MOVEMENT THEORY APPROACH

This exploratory, diachronic study compares the politics of Islamisation, which have undergone different patterns of developmentin both Nigeria and Malaysia. Islamisation is defined as an ideological translation of Islamism into policies to “Islamise” the state andsociety by expanding the scope of the application of Islamic laws and principles. Islamisation in Malaysia has been implemented steadily and progressively since the 1980s. It involves the “inculcation of Islamic values” in a wide range of aspects of society, including the economy. The Islamic penal code or hudud enactments were legislated in two states, but held in abeyance due to their unconstitutionality. In contrast, Nigeria observed the sudden and erratic implementation of hudud in 12 northern states in 1999, along with other bureaucratic adjustments. Adopting an interpretative case study approach of the comparative method of Arend Lijphart, we explain the two contrastive case studies of the ideological translation of Islamism by analysing the manner in which various political opportunities and structural constraints in the respective cases have shaped the Islamisation process. Data gathering was based on an extensive review of the related body of literature. Analysis was conducted using a social movement theoretical framework based on a structured, focused comparison. The dynamic conceptualisation of the state as a set of institutions, which is continually and dialectically reshaped by contentious processes, captures how the bureaucratisation and judicialisation of Islam have modified the nature of state structures and the structure of political opportunities, which in turn allows for additional channels of influence for Islamic activists.

Unraveling wage inequality: tangible and intangible assets, globalization and labor market regulations

In this paper, we study the asymmetric effects of different types of capital-embodied technological change, as proxied by tangible and intangible assets, on relative wages (high- to medium-skilled, high- to low-skilled and medium- to low-skilled workers), relying upon the technology-skill complementarity and polarization of the labor force frameworks. We also consider two additional major channels that contribute to shaping wage differentials: globalization (in terms of trade openness and global value chains participation) and labor market institutions. The empirical analysis is carried out using a panel dataset comprising 17 mostly advanced European economies and 5 industries, with annual observations spanning the period 2008–2017. Our findings suggest that software and databases—as a proxy for intangible technologies—exert downward pressure on low-skilled wages, while robotics is associated with a polarization of the wage distribution at the expense of middle-skilled labor. Additionally, less-skilled workers’ relative wages are negatively affected by trade openness and global value chain participation, but positively influenced by sector-specific labor market regulations.

Structure analysis of double comb about jet spinning machine based on CFD

PurposeAs a new type of spinning machine, the jet spinning machine absorbs the carding system of the rotating cup spinning series and the nozzle part of the jet spinning. This paper aims to intends to introduce the double carding structure currently studied by the rotating cup spinning into the jet spinning machine, and analyze the influence of the nozzle characteristic number on the flow field in the double carding structure to verify the advantages of the double carding structure.Design/methodology/approachThe simulation is used to evaluate the performance of single/double split jet spinning and nozzle feature number, verify the technical advantages of double split jet spinning and evaluate the influence of nozzle feature number on flow field. The influence of the nozzle characteristic number on the flow pattern in the four models is compared. The advantages and disadvantages of a conventional single comb and a double comb with a bypass channel on the longer side of the transport channel as an additional air supply channel are also evaluated.FindingsAt present, the double comb technology of rotary cup spinning is being studied at home and abroad to improve the spinning quality and improve the difficult problem of mixed yarn with large difference in processing fiber properties. At present, the jet spinning machine combines the advantages of rotary cup spinning and jet spinning, absorbing the comb system of rotary cup spinning series and the nozzle part of jet spinning. Therefore, it is found that the introduction of the double-split structure into the wool jet spinning has research value to improve the spinning quality.Originality/valueThe purpose of this paper is to refer to the previous research on the double comb structure in rotary spinning, and to apply the double comb structure in the new jet spinning machine to improve the spinning quality. The simulation is used to evaluate the performance of single/double split jet spinning and nozzle feature number, verify the technical advantages of double split jet spinning and evaluate the influence of nozzle feature number on flow field.