Search

In this work, the excess water-stagnation issue in the high current region in direct methanol fuel cells (DMFCs) is resolved by using atomic precision modulated nitrogen-crafted graphene (NG) in the cathode microporous layer by utilizing simplistic, industrial-expansive and ecological strategy. Few-layer 2D-graphene (∼2–5 nm thickness) is prepared by bath sonication approach from abundant feedstock-graphite and is treated with nitric acid to yield 1.8 wt.% uniformly dispersed nitrogen containing NG. Specifically, 1:4 weight ratio NG:carbon-black (CB) hybrid architecture, displays 0.252 V in 370 mA cm−2with the peak power density of 93.4 mW cm−2, improving cell power density by 45.6% compared with standard one at 60°C and 1 mol/L methanol/oxygen conditions at ultra-low catalyst loadings and displaying exceptional stability. Atomic insights into NG reveal that interplay between bonding configurations, altered hydrophobic/hydrophilic porosity of graphene (10.6% less wettability from contact angle and 13.1% high electrode porosity measurements) contribute to the better mass-transport-porogenic effect (16.3% high oxygen-permeability), mildly affecting the electron pathway (6.5% reduced in-plane electrical conductivity), overall significantly improving cell performance. Altogether, this work delivers multiple advantages, i.e., the usage of material from facile, sustainable and cost-effective routes, while improving DMFC performance with potential industrial promise.

To facilitate the large-scale application of direct methanol fuel cells (DMFCs), the issue of low Pt/C durability due to Pt degradation and carbon corrosion in harsh DMFC operating conditions must be addressed. A promising strategy is to hybridize metal oxides with carbon materials, resulting in a durable and conductive support that exhibits a strong metal-support interaction (SMSI) effect on platinum nanoparticles (Pt NPs). In this study, we introduced a TiO2 coating on carbon black, creating a TiO2 nanolayer between Pt and carbon black. The nanolayer not only protects the carbon black but also activates the SMSI effect on Pt. The resulting Pt/C@TiO2 electrocatalyst exhibits superior durability than commercial Pt/C. After the accelerated durability test, the mass activity loss of the methanol oxidation reaction (MOR) of Pt/C@TiO2 (32%) is significantly lower than that of Pt/C (46.8%). Moreover, the MOR activity of Pt/C@TiO2 is higher than Pt/C as well. It suggests that Pt/C@TiO2 shows great potential as a highly durable and active electrocatalyst for DMFCs.

The urban agglomeration in the middle reaches of the Yangtze River (UAMRYR) is a key area to promote the central region rise and the green development of the Yangtze River Economic Belt. In this paper, an evaluation index system was comprehensively constructed for the green development level of the UAMRYR from five aspects: resource utilization, green environment, green economy, green life, and support mechanisms. Entropy weight-TOPSIS method and multivariate statistical method, including spatial autocorrelation analysis and geographic detectors, were used to analyze the regional differences and influencing factors of the green development level of the UAMRYR from 2008 to 2018. The results showed that: (1) the overall green development level of the UAMRYR showed a fluctuating upward trend from 2008 to 2018, among which the provincial capital cities such as Wuhan, Changsha, and Nanchang, as well as the cities covered by the Poyang Lake urban agglomeration had relatively higher green development levels. (2) The green development level of the 31 cities in the UAMRYR showed insignificant spatial heterogeneity within the study period. Compared with other areas, the green development levels varied greatly among the regions of the Wuhan metropolitan area, which was a typical high-low aggregation type. (3) Green economy, green life, and support mechanisms were the highly influential aspects of the green development of the UAMRYR, and the main influencing factors were the total value added of secondary and tertiary industries, urbanization rate, and fixed asset investment. The explanatory power of the interaction of influencing factors on the green development of the UAMRYR was greater than that of a single factor. This study is intended to provide a reference for the green transformation development and the coordinated development of the “resources-environment-economy” in the UAMRYR.

In our study, we introduce an innovative energy management system optimized for energy hubs in net-zero energy smart cities, emphasizing sustainability as a core objective. Our approach intricately integrates distributed generation systems and storage facilities within a digital twin framework, incorporating landscape considerations to promote environmental harmony. By prioritizing sustainability, our strategy aims to minimize operational costs while maximizing energy efficiency and reducing carbon emissions. We employ specialized energy flow algorithms for each grid, designing energy hubs that leverage renewable resources and mobile storage to enhance sustainability. To address complexity, our model utilizes a non-convex mixed-integer nonlinear programming structure and robust adaptive optimization techniques, combining the Gray Wolf and Krill Herd algorithms. Through simulations, we demonstrate significant improvements in power system efficiency, including notable reductions in power loss, peak voltage fluctuations, and temperature variations. Our research underscores the critical role of smart landscaping in advancing sustainable energy management for net-zero energy smart cities, facilitating seamless integration of energy hubs with the surrounding landscape within a digital twin paradigm.

We propose a Hermite–Gaussian (HG) mode-demulti-plexing hybrid (MDH) for coherent detection of mode-division multiplexed signals. The MDH, which performs multiple functionalities, including demultiplexing, local oscillator splitting, and optical 90-deg mixing, is realized based on the multi-plane light conversion technique. An isosceles right triangle output layout is employed to reduce the number of phase masks to fewer than the number of modes, significantly simplifying the construction of the MDH. A 10-Hermite–Gaussian (HG) mode MDH with only five phase masks is demonstrated by numerical simulation, achieving an insertion loss (IL) and mode dependent loss as low as ${-}{2.3}$−2.3 and 1.7 dB, respectively. The IL was further reduced to ${-}{1.5}\;{\rm dB}$−1.5dB through optimization of MDH parameters, such as the beam waists of the input HG modes and the output spots.

Background Telbivudine (LdT) and tenofovir (TDF) are widely used in pregnant women to prevent vertical transmission; however, limited data are available on the differences in clinical efficacy and safety between the two drugs.Methods A total of 307 hepatitis B e antigen (HBeAg)-positive pregnant women with complete follow-up data were enrolled, the patients with alanine aminotransferase (ALT) levels <1xULN at baseline were enrolled to cohort 1 for treatment from 28 ±4 weeks gestation to delivery, while ALT levels >1xULN at baseline were enrolled to cohort 2 for treatment from 28 ±4 weeks gestation and continued after delivery. The clinical efficacy and safety was compared in LdT- and TDF-treated patients. In addition, 32 patients in cohort 1 were analysed for nucleoside analogue (NA)-related resistance mutations at baseline and after delivery.Results The results showed that HBV DNA levels were significantly lower at delivery than at baseline (P<0.001), but the decreases in HBV DNA, ALT, total bilirubin and total bile acid levels did not differ between the LdT- and TDF-treated patients at different time points (P>0.05) in the two cohorts. However, gastrointestinal adverse effects (vomiting) occurred more frequently in TDF-treated than LdT-treated patients (6.6% versus 0.0%; P=0.001). The results of NA-related resistance mutations analysis in cohort 1 revealed that short-term LdT or TDF treatment did not significantly change the NA-related resistance mutations (P>0.05).Conclusions This study revealed that the clinical efficacy in LdT- or TDF-treated HBeAg-positive Chinese pregnant women is similar, and gastrointestinal adverse effects occurred more frequently in TDF-treated patients.

Highway-rail grade crossings (HRGCs) are unique nodes in the transportation system that facilitate the movement of rail and highway traffic. Various mathematical models are available that provide safety assessments of HRGCs. A chief ingredient of these models is the annual average daily traffic (AADT). One of the main sources of data for such models is the Federal Railroad Administration (FRA)’s Grade Crossing Inventory. A substantial portion of the AADT data in the inventory is outdated. This paper investigates the effects of using out-of-date rather than up-to-date AADT values, using two safety assessment models to isolate the differences. Results show that the use of out-of-date AADT data generates biased rankings of HRGCs based on safety considerations. Since collection of AADT data is resource-intense, a methodology based on a geographic information system for estimating updated AADT is presented. This methodology utilizes limited traffic counts that are supplemented with additional publicly available data. An application using a geographically weighted Poisson regression model for 14 HRGCs gave results that closely matched AADT values based on 2018 field traffic counts at those HRGCs. This method provides an alternative to costly field-data-based updating of AADT in the relatively extensive Grade Crossing Inventory database. Limitations of the research and suggestions for future research complete this paper.

Graphical abstract:

Graphene-based laminar membranes open new avenues for water treatment; in particular, reduced graphene oxide (rGO) membranes with high stability in aqueous solutions are gaining increased attention for desalination. However, the low water permeability of these membranes significantly limits their applications. In this study, the water permeability of thermally reduced GO membrane was increased by a factor of 26 times by creating in-plane nanopores with an average diameter of ∼3 nm and a high density of 2.89 × 1015m–2via H2O2oxidation. These in-plane nanopores provide additional transport channels and shorten the transport distance for water molecules. Meanwhile, salt rejection of this membrane is dominated by both the Donnan effect and the size exclusion of the interspaces. Besides, the water permeability and salt rejection of the thermally reduced nanoporous GO membrane can also be simply tuned by adjusting the thermal treatment time and membrane thickness. Additionally, the fabricated membrane exhibited a relatively stable rejection of Na2SO4during the long-term testing. This work demonstrates a novel and effective strategy for fabricating high-performance laminar rGO membranes for desalination applications.

Droplets sliding on surfaces always exhibit an advancing and a receding contact angle. When exerting different driving forces on the droplet to force it to slide at different velocities, the droplet would alter its shape to adapt to the new motion. Hence, different advancing/receding contact angles are likely to be observed, leading to the multiple contact angle hysteresis on a given surface. To verify this hypothesis, many-body dissipative particle dynamics is employed to perform the sliding simulation on both chemically homogeneous and heterogeneous surfaces. By ensuring the droplet sliding in uniform motions under different driving forces, the advancing/receding contact angles are recorded for analysis. Simulation results show that, for homogeneous surfaces, a larger driving force can result in both larger advancing contact angle and smaller receding contact angle, while for heterogeneous surfaces, increasing the driving force only results in smaller receding contact angles. For both cases, multiple contact angle hysteresis can be observed. These observations are contrary to the currently prevailing opinion, which believes that the contact angle hysteresis should be unique on given surfaces. Our findings would advance the understanding of wetting phenomena and possibly inspire new guidance for the design of functional interfaces.

We evaluate the coupling efficiency from free space to few-mode fibers (FMF). A theoretical coupling model is developed based on the imaging properties of free-space modes and the inner products between the free-space modes and the FMF modes. Numerical results for six- and ten-mode free-space-to-FMF coupling are presented. It is found that in order to maximize the total coupling efficiency, the size of the highest-order free-space and fiber modes should be approximately matched, and there is an optimum value for the V number of the FMF. In addition, the axial alignment tolerance for free-space-to-FMF coupling is more stringent than for single-mode cases.

The equilibrium state of a droplet deposited on chemically heterogeneous surfaces is studied by using many-body dissipative particle dynamics. The length ratio covers 2 orders from 0.01 to 1 and allows a systematical inspection of the changes of the droplet shape, contact angle, and aspect ratio with this parameter. Moreover, a new parameter, global aspect ratio, is introduced to better characterize the distortion of the droplet. It is found that the droplet shape at the equilibrium stage strongly lies on the deposition position when the length ratio is beyond 0.1. Additionally, the lateral displacement is observed when depositing the droplet on the border of two stripes at large length ratios (over 0.1). On the other hand, the Cassie area fraction also has a significant effect on the wetting behaviors. When the droplet is driven by a body force with a 45° inclined angle to the stripes, the moving direction could be strictly in line with the force direction, deviating from the force direction, or totally in line with the stripes, depending on the length ratio.

A novel thin-film nanocomposite forward-osmosis (FO) membrane was fabricated on hydrophilic nylon microfiltration (MF) support by interfacial polymerization with the assistance of an intermediate layer of graphene oxide and multiwall carbon nanotube (GO/MWCNT). The chemical composition, structure, and surface properties of the synthesized FO membranes were studied using various characterization methods. It was found that the GO/MWCNT composite layer not only provided ultrafast nanochannels for water transport but also reduced the thickness of the polyamide layer by up to 60%. As a result, the novel FO membrane exhibited a higher water flux and lower reverse salt flux compared with the membrane synthesized without the GO/MWCNT intermediate layer. This method offers promising opportunities to fabricate thin-film composite membranes on microfiltration substrates for FO application with inhibited concentration polarization phenomenon and expected separation performance.

This paper presents an experimental investigation utilizing ordinary Portland cement (OPC), carbon nanotube (CNT), metakaolin (MK) and 1.75% polyethylene (PE) fibres to develop a high performance CNT and fibre-reinforced ultra-lightweight cementitious composites (ULCC). Ultra-low density was achieved by using cenospheres. The effects of different dosages of CNT, different types of binders and PE fibres were investigated. The workability, hardened properties (density, compressive strength and flexural strength), sorptivity, microstructure and cost of each mix were also investigated. From this experiment, PE and CNT-reinforced high-strength ULCC with a dry density of around 1500 kg/m3, compressive strength of around 87 MPa and flexural strength of around 18 MPa with flexural hardening can be produced. The effect of CNT and the synergic effect of CNT and PE fibres were investigated and discussed. The synergic effect of CNT was better than the combination of the separate effects of CNT and PE fibres. Compared to the reference mix MRF, when combined with 1.75% PE fibres, 0.2%, 0.4%, 0.6% CNT can improve 260%, 276% and 239% of flexural strength, increase by 35.6%, 61% and 58.5% of compressive strength, 4.5%, 29% and 21.3% for specific strength. It was found that the cost of each mix increases by around 1067 AUD per cubic meter by the increase of 0.2% CNT in each mix. Finally, from multi-criteria analysis, M0.4CNTPE was recommended in this study.

Liver injury in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant- and Omicron subvariant-infected patients is unknown at present, and the aim of this study is to summarize liver injury in these patients.

Graphical Abstract: This review focuses on the synthesis process of Pt-based electrocatalysts/C to develop aqueous one-pot synthesis at large-scale production for PEMFC stack application.

Significant progress has been made in the development of non-precious metal electrocatalysts (NPMEs) during the past decade. Correspondingly, there is an urgent demand for an appropriate measurement method to be established for the reliable evaluation of NPMEs. In this study, platinum and graphite counter electrodes were used to investigate the impact of counter electrode material on the accelerated durability testing (ADT) of NPMEs in acidic medium. Platinum used as the counter electrode in a traditional three-electrode electrochemical cell was found to dissolve in acidic medium and re-deposit on NPME coated on the working electrode during ADT. Such re-deposition causes the oxygen reduction reaction (ORR) performance of NPMEs to remarkably improve, and thus will seriously mislead our judgment of NPMEs if we are unaware of it. The phenomenon can be avoided using a graphite counter electrode.

The extrahepatic manifestations of hepatitis E virus (HEV) infection include hemolytic anemia. However, the clinical characteristics of HEV-induced hemolytic anemia have been only sporadically reported in case reports, and there is a scarcity of relevant systematic reviews. The aim of the current study was to analyze and summarize the clinical characteristics of patients diagnosed with HEV-induced hemolytic anemia.

Introduction This study is aimed at the determination of the effect of the immune-regulatory factor NLRX1 on the antiviral activity of hepatocytes against an external stimuli favoring hepatitis B virus infection, and to explore its mechanism of action.Methods A HepG2-NTCP model was established using the LV003 lentivirus. Cells were transfected using an overexpression vector and NLRX1 siRNA to achieve overexpression and interference of NLRX1 expression (OV-NLRX1, si-NLRX1). Levels of HBsAg and HBcAg were determined using Western blotting analysis and immunohistochemical analysis. The levels of hepatitis B virus DNA and hepatitis B virus cccDNA were determined by real-time quantitative polymerase chain reaction. The expression and transcriptional activity of IFN-α, IFN-β, and IL-6 were measured using real-time quantitative polymerase chain reaction, enzyme-linked immunosorbent assay, and promoter-luciferase reporter plasmids. Co-immunoprecipitation was used to determine the effect of NLRX1 on the interaction between MAVS and RIG-1. Western blotting was used to obtain the phosphorylation of essential proteins in the MAVS-RLRs signaling pathways.Results NLRX1 promoted HepG2-NTCP cell hepatitis B virus infection. Compared to the control group, the levels of HBsAg, HBcAg, hepatitis B virus cccDNA, and hepatitis B virus DNA increased in the OV-NLRX1 group and decreased in the si-NLRX1. Co-immunoprecipitation results showed that NLRX1 competitively inhibited the interaction between MAVS and RIG-1, and inhibited the phosphorylation of p65, IRF3, and IRF7. Additionally, NLRX1 reduced the transcription activity and expression levels of the final products: IFN-α, IFN-β, and IL-6.Conclusions NLRX1 can counteract innate immune response induced by an external stimuli favoring hepatitis B virus infection by competitive inhibition of MAVS-RLRs signaling in HepG2-NTCP cells. Inhibition of the MAVS-RLR-mediated signaling pathways leads to a decline in the expression levels of I-IFN and IL-6.

Space-division multiplexing (SDM) has attracted significant attention in recent years because larger transmission capacity is enabled by more degrees of freedom (DOFs) in few-mode fibers (FMFs) compared with single-mode fibers (SMFs). To transmit independent information on spatial modes without or with minor digital signal processing (DSP), weakly-coupled FMFs are preferred in various applications. Several cases with different use of spatial DOFs in weakly-coupled FMFs are demonstrated in this work, including single-mode or mode-group-multiplexed transmission, and spatial DOFs combined with time or frequency DOF to improve the system performance.

The ISO12103-1 A2 test dust was used as the reference in the calibration device of the atmospheric particle monitor to investigate the performance of the self-made standard dust in this study. The result indicated that when the aerosol concentration of the calibration device was 500ug/m3,400ug/m3, 200ug/m3,100ug/m3 and 50ug/m3, the stability of self-made standard dust was close to the ISO12103-1 A2 test dust. In addition, when the aerosol with high concentration of 500ug/m3, medium concentration of 200ug/m3 and low concentration of 50ug/m3, the homogeneity and obtained concentration of the self-made standard dust and the ISO12103-1 A2 test dust evaluated by filter membrane sampling were not much differencd. Therefore, the self-made standard dust can replace ISO12103-1 A2 test dust to be used in the calibration device of particle monitor.