Analysis of Entrainment Ratio about Solar Ejector Refrigerant System

AbstractBased on the VB program, establish a simulation program about the solar ejector system performance. The characteristic of entrainment ratio has been analyzed when the HFC134a, R290 and R718 are adopted as working fluid respectively. It is found that the entrainment ratio of R290 is the biggest over the range of operating conditions, and the entrainment ratio of HFC134a is the middle, and the R718's is the least. The entrainment ratio of the system increases with increasing of the generator temperature and evaporator temperature, and decreases with increasing of the condenser temperature in the research of operating range, and the influence of condenser temperature on the ejector refrigerant system is more than the generator temperature and evaporator temperature. The research will provide theoretical support for solar ejector refrigeration technology optimization design and extension

Renewable Energy for Balancing Carbon Emissions and Reducing Carbon Transfer under Global Value Chains: A Way Forward

Research on the relationship between a country’s renewable energy consumption and carbon emissions is of great significance for reducing carbon emissions embodied in international trade. There always exists a gap between production-based and consumption-based carbon emissions. Accordingly, this paper investigates the influence of renewable energy consumption on carbon emission balance, the ratio of production-based emissions to consumption-based emissions, in various countries using the ordinary least square (OLS) method and generalized method of moments (GMM) method. We found that a 1% increase in renewable energy consumption can decrease the carbon emission balance by 5.8%. Furthermore, renewable energy consumption can help narrow the gap between production-based and consumption-based carbon emissions in net emission exporters. In addition, renewable energy consumption can also weaken the negative impact of the global value chains (GVCs) division system on the carbon emission balance. The findings in this study fill the research gap by analyzing the heterogeneous impacts of renewable energy consumption on carbon emission balance embodied within a GVC division system in various countries and provide policy suggestions that renewable energy consumption should be encouraged in net emission exporters to reduce the carbon emission transfers

Synergistic Lubrication Mechanism of Nano-Fluid and Grinding Wheel Prepared by CNTs@T304 Nano-Capsules

Grinding fluid often struggles to enter the grinding area and overcoming this challenge has been a major focus of research in recent years. Therefore, CNTs@T304 nano-capsules are prepared by filling the cavities of CNTs with a lubricant of T304. CNTs@T304 nano-capsules were used as an additive in this paper to prepare resin grinding wheels and nanofluids, respectively. The resin wheels filled with nano-capsules were used for grinding under the lubrication of nanofluids, and T304 could then be released to the grinding area to play a self-lubricating role during grinding. First, CNTs@T304 nano-capsules were characterized, and the properties of the prepared grinding wheels and nanofluids were tested. Second, the effects of the filling of nano-capsules and grinding speed on the grinding force, grinding temperature, surface roughness, and grinding ratio were studied. Finally, the lubrication mechanism of the nano-capsules was revealed through surface analysis of the workpiece. The results suggested that nano-capsules had good thermal stability and the nanofluid prepared from them exhibited good dispersion stability and thermal conductivity. The grinding wheel was found to satisfy the service conditions when the filling content was less than 15%. Compared with a common wheel, the grinding force and grinding temperature were reduced by 24% and 28%, respectively, and the surface roughness of the workpiece and the grinding ratio were increased by 18% and by 21%, respectively, when grinding GCr15 steel with the nano-capsule wheel. Lubrication with nanofluids could further reduce the grinding force, grinding temperature, and surface roughness values. During grinding, the self-lubrication film formed by the T304 released from the nano-capsules in the wheel served first and foremost as a lubricant. The intervention of the nanofluid enhanced the heat-exchange effect and lubrication efficiency in the grinding zone

Modulating interlayer and intralayer excitons in WS2/WSe2 van der Waals heterostructures

Intralayer and interlayer excitons are fundamental quasiparticles that can appear simultaneously in transition metal dichalcogenide van der Waals heterostructures. The understanding and modulation of the interaction of interlayer and intralayer excitons are of great importance for both fundamental studies and device applications. Here, we demonstrate the modulation of photoluminescence (PL) emissions of interlayer and intralayer excitons in WSe2/WS2 heterostructures using different stacking configurations in a single sample, including with and without hexagonal boron nitride (hBN) encapsulation and different hBN spacing layers. By temperature dependent PL spectroscopy, we observed the suppression of interlayer exciton formation and exciton complexes at high temperatures due to enhanced phonon scattering. We also verify the formation of these states via power dependent spectroscopy. Our electric field and doping dependent PL studies reveal that the interlayer exciton peaks shift linearly with the applied gate voltage and the intralayer excitons of WSe2 (WS2) are dominant at high n-doping (p-doping). Our results contribute to the understanding of the interplay between interlayer and intralayer excitons in WSe2/WS2 heterostructures and could promote the related exitonic device applications

Effect of Choline-Based Deep Eutectic Solvent Pretreatment on the Structure of Cellulose and Lignin in Bagasse

Deep eutectic solvents (DESs) is a newly developed green solvent with low cost, easy preparation and regeneration. Because of its excellent solubility and swelling effect in lignocellulose, it has received widespread attention and recognition. In this study, choline-based deep eutectic solvents (DESs)—choline chloride-urea (CC-U), choline chloride-ethylene glycol (CC-EG), choline chloride-glycerol (CC-G), choline chloride-lactic acid (CC-LA), and choline chloride-oxalic acid (CC-OA)—were used to extract and separate bagasse. The effects of hydrogen bond donors on lignin separation and the fiber and lignin structure were investigated. All five DESs could dissolve lignin from bagasse; acidic DESs exhibited higher solubility than basic DESs. CC-OA effectively separated lignin and hemicellulose. CC-LA showed weaker lignin separation ability than CC-OA. CC-G, CC-EG, and CC-U were more inclined to selectively separate lignin than hemicellulose. The crystalline cellulose II structure was retained after DES pretreatment. Acidic DESs effectively improved the crystallinity of bagasse fiber; the crystallinities for CC-OA and CC-LA pretreatment were 62.26% and 61.65%, respectively. The lignin dissolved in DES was mainly syringyl lignin. The lignin dissolved in CC-U, CC-LA, and CC-OA contained a small amount of guaiacyl lignin

DataSheet1_Prognostic analysis of m6A-related genes as potential biomarkers in idiopathic pulmonary fibrosis.ZIP

Idiopathic pulmonary fibrosis (IPF) is a progressive, fatal lung disease with limited treatment options. N6-methyladenosine (m6A) is a reversible RNA modification and has been implicated in various biological processes. However, there are few studies on m6A in IPF. This project mainly explores the prognostic value of m6A-related genes as potential biomarkers in IPF, in order to establish a set of accurate prognostic prediction model. In this study, we used GSE28042 dataset in GEO database to screen out 218 m6A-related candidate genes with high IPF correlation and high differential expression through differentially expressed gene analysis, WGCNA and m6A correlation analysis. The genes associated with the prognosis of IPF were screened out by univariate Cox regression analysis, LASSO analysis, and multivariate Cox regression analysis, and the multivariate Cox model of prognostic risk of related genes was constructed. We found that RBM11, RBM47, RIC3, TRAF5 and ZNF14 were key genes in our model. Finally, the prognostic prediction ability and independent prognostic characteristics of the risk model were evaluated by survival analysis and independent prognostic analysis, and verified by the GSE93606 dataset, which proved that the prognostic risk model we constructed has a strong and stable prediction efficiency.</p

Recent Advances in Sustainable Antimicrobial Food Packaging: Insights into Release Mechanisms, Design Strategies, and Applications in the Food Industry

In response to the issues of foodborne microbial contamination and carbon neutrality goals, sustainable antimicrobial food packaging (SAFP) composed of renewable or biodegradable biopolymer matrices with ecofriendly antimicrobial agents has emerged. SAFP offers longer effectiveness, wider coverage, more controllability, and better environmental performance. Analyzing SAFP information, including the release profile of each antimicrobial agent for each food, the interaction of each biomass matrix with each food, the material size, form, and preparation methods, and its service quality in real foods, is crucial. While encouraging reports exist, a comprehensive review summarizing these developments is lacking. Therefore, this review critically examines recent release-antimicrobial mechanisms, kinetics models, preparation methods, and key regulatory parameters for SAFPs based on slow- or controlled-release theory. Furthermore, it discusses fundamental physicochemical characteristics, effective concentrations, advantages, release approaches, and antimicrobial and preservative effects of various materials in food simulants or actual food. Lastly, inadequacies and future trends are explored, providing practical references to regulate the movement of active substances in different media, reduce the reliance on petrochemical-based materials, and advance food packaging and preservation technologies

Picosecond electrical response in graphene/MoTe2 heterojunction with high responsivity in the near infrared region

Understanding the fundamental charge carrier dynamics is of great significance for photodetectors with both high speed and high responsivity. Devices based on two-dimensional (2D) transition metal dichalcogenides can exhibit picosecond photoresponse speed. However, 2D materials naturally have low absorption, and when increasing thickness to gain higher responsivity, the response time usually slows to nanoseconds, limiting their photodetection performance. Here, by taking time-resolved photocurrent measurements, we demonstrated that graphene/MoTe2 van der Waals heterojunctions realize a fast 10 ps photoresponse time owing to the reduced average photocurrent drift time in the heterojunction, which is fundamentally distinct from traditional Dirac semimetal photodetectors such as graphene or Cd3As2 and implies a photodetection bandwidth as wide as 100 GHz. Furthermore, we found that an additional charge carrier transport channel provided by graphene can effectively decrease the photocurrent recombination loss to the entire device, preserving a high responsivity in the near-infrared region. Our study provides a deeper understanding of the ultrafast electrical response in van der Waals heterojunctions and offers a promising approach for the realization of photodetectors with both high responsivity and ultrafast electrical response

Manipulating Picosecond Photoresponse in van der Waals Heterostructure Photodetectors

Self-powered ultrafast 2D photodetectors have demonstrated great potential in imaging, sensing, and communication. Understanding the intrinsic ultrafast charge carrier generation and separation processes is essential for achieving high-performance devices. However, probing and manipulating the ultrafast photoresponse is limited either by the temporal resolution of the conventional methods or the required sophisticated device configurations. Here, van der Waals heterostructure photodetectors are constructed based on MoS2/WSe2 p–n and n–n junctions and manipulate the picosecond photoresponse by combining photovoltaic (PV) and photothermoelectric (PTE) effects. Taking time-resolved photocurrent (TRPC) measurements, a TRPC peak at zero time delay is observed with decay time down to 4 ps in the n–n junction device, in contrast to the TRPC dip in the p–n junction and pure WSe2 devices, indicating an opposite current polarity between PV and PTE. More importantly, with an ultrafast photocurrent modulation, a transition from a TRPC peak to a TRPC dip is realized, and detailed carrier transport dynamics are analyzed. This study provides a deeper understanding of the ultrafast photocurrent generation mechanism in van der Waals heterostructures and offers a new perspective in instruction for designing more efficient self-powered photodetectors.Comprehensive understanding of interaction between photovoltaic and photothermoelectric effects is demonstrated via a time-resolved photocurrent (TRPC) measurement technique. Compared to MoS2/multilayer WSe2 p–n junction having a conventional TRPC dip, MoS2/1L WSe2 n–n junction processes a distinct TRPC peak, which is attributed to the opposite polarity between photovoltaic and photothermoelectric currents and can be further modulated via an external bias.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/173088/1/adfm202200973_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/173088/2/adfm202200973-sup-0001-SuppMat.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/173088/3/adfm202200973.pd