We established a calculation model of the conductivity of multilayer graphene based on Boltzmann transport equation and 2D electron gas theory. Numerical simulations show that the conductivities of ...few-layer graphene and graphene nanosheets are reduced when thickness is increased. The reduction rate decreases for micron-range thicknesses and remains constant thereafter. Moreover, the conductivity increases with the increase in temperature, in which the increase rate declines as temperature increases. Higher thickness exhibits a more obvious temperature effect on conductivity. Such effect also increases with the increase in temperature.
•Two types of carrier transport channels, surface channel and interlayer channel, were advised.•Electron scattering mechanism in the surface channel and interlayer channel were investigated.•The calculation model of the conductivity of multilayer graphene was established.•Temperature- and thickness-dependent conductivity of FLG and GNs was simulated.•Numerical simulation results are consistent with the published experimental results.
This paper presents a semi-Lagrangian meshless framework based on the localized radial basis function collocation method and the second-order explicit Runge–Kutta method (RK2-LRBFCM) for analyzing ...the sloshing phenomenon in a 2D tank. In the present method, the semi-Lagrangian approach is adopted to constrain the lateral movements of inner collocation nodes. And the LRBFCM is used to obtain the velocity potentials at each time instant governed by Laplace equation, then second-order explicit Runge–Kutta method is introduced to calculate the free-surface elevation and velocity potential at the next time instant. In comparison with the reference results, the efficiency and accuracy of the proposed RK2-LRBFCM are demonstrated in the solutions of several benchmark examples including horizontally excited tanks, vertically excited tanks, horizontally and vertically excited tanks. Moreover, the effect of the protrusion (shape and size) of the bottom wall on the sloshing phenomenon in horizontally excited tank is investigated.
Poly(ethylene oxide) (PEO), an important solid polymer electrolyte (SPE) for solid‐state lithium batteries, suffers from low ionic conductivity and poor electrochemical stability; many inorganic ...solid compounds have been explored as fillers to address these issues. Herein, we report that Al‐metal organic framework (MOF) nanorods could work as efficient solid fillers to boost the electrochemical performance of PEO‐based SPEs. The addition of MOF nanorods was found to inhibit the crystallization of PEO and effectively weaken the interactions among the PEO chains, resulting in evidently enhanced ionic conductivity and improved electrochemical stability; moreover, when embedded in PEO, such Al‐MOF nanorods are microporous and micrometer long, which are expected to favor the transportation of Li+ over the significantly more bulky anions TFSI−. Compared with pure PEO SPE, our optimal sample PEO‐MOF5% SPE has higher ion conductivity (2.09×10−5 S/cm at 30 °C and 7.11×10−4 S/cm 60 °C), a larger lithium‐ion transference number (0.46) and an enlarged electrochemical window (4.7 V versus Li/Li+). Accordingly, the cell of LiFePO4/PEO‐MOF5%/Li shows excellent cycle performance and rate performance. Our work proved the advantages of MOF particles as solid fillers towards high‐performance PEO‐based SPE, and we also put emphasis on the shape effect of the solid fillers on the lithium‐ion transference number and, thus, the electrochemical performance of the resulting SPE.
Stable cycling: The incorporation of microporous metal‐organic framework (MOF) nanorods in poly(ethylene oxide) (PEO)‐based solid polymer electrolyte leads to decreased polymeric crystallinity, improved ionic conductivity and enhanced lithium‐ion transference number, which enables better cycling stability and rate performance for the relevant all‐solid‐state battery LiFePO4/PEO‐MOF5%/Li.
In aqueous solutions, electro/chemically deposited metals usually grow outward into electrolyte. Here we report that the reduced Al grows inward into the sample, surprisingly, while Mg (in pure Mg ...and Al2Mg3 alloy) is galvanically replaced with Al in an ionic liquid. The galvanic replacement reaction (GRR) of Al2Mg3 involves a dealloying process that generates a nanoporous Al skeleton, and simultaneously the inward-growth plating of Al that thickens the Al skeleton. The obtained open nanoporous Al might be interesting for many applications including lithium-ion batteries. The anomalous inward-growth of deposited Al is attributed to the low diffusivity of ionic liquid and the negative charge of reduced species. This dealloying/GRR procedure provides a new route to produce hierarchical nanoporous structure in bulk materials.
Crane usage is pervasive on construction sites, however, it is associated with a notably high accident rate. The analyzing of crane accident risks is essential for accident prevention, control, and ...ensuring the safety of lifting operations. Hence, significant emphasis should be placed on understanding the interaction among various risk factors. This paper proposes a quantitative coupling method for human, machine, management, and environmental risk factors in crane accidents, leveraging Bayesian networks (BN) and the N-K model. Firstly, text mining technology and fault tree analysis are employed to analyze the causes of crane accidents and categorize the associate risk factors. Secondly, the types of risk coupling resulting from human, machine, management, and environmental risk factors are defined. Thirdly, the BN model is developed based on the analysis of crane accident risksand its N-K model. Fourthly, the parameters of the risk coupling nodes in the developed BN are determined based on the calculation results of the N-K model. Finally, for the risk coupling types with high coupling values and the first-level node and second-level node, the failure probability is analyzed through posterior probability and sensitivity analysis. The results indicate that factors related to man and management significantly impact crane accidents and warrant enhanced attention. The interplay among multiple risk factors significantly influences the probability of crane accidents, necessitating careful attention.
Androgenesis is an important chromosome set manipulation technique used in sex control in aquaculture. Haploid embryos exhibit haploid syndrome with body abnormalities and even die during early ...embryonic development. In this study, we used whole genome bisulfite sequencing (WGBS) to investigate the genome-wide DNA methylation profiles in haploid females (1n-X) and males (1n-Y), and diploid females (2n-XX) and males (2n-XY) of tiger pufferfish (Takifugu rubripes), an economically important fish in China. A total of 96.32 Gb clean data was produced. Differentially methylated regions (DMRs) were found between haploids and diploids, which may be related to abnormal development and early embryonic death in haploids. There were 3,641 hyper-methylated differentially methylated genes (DMGs) and 2,179 hypo-methylated DMGs in haploid vs. diploid comparisons in both females and males. These DMGs were mainly related to genomic stability maintenance and cell cycle regulation. slf1, actr8, gas2, and pbrm1 genes were selected to validate the methylation sequencing. After combining the methylation data with the corresponding transcriptome data, we identified several genes, including guca2a, myoc, fezf2, rprml, telo2, s100a1, and marveld1, which exhibited differential expression levels modulated by DNA methylation. In conclusion, our study revealed different methylation and expression profiles between haploid and diploid T. rubripes for the first time. Several DMGs were identified between different ploidy levels, which may be related to haploid syndrome formation. The results expand the understanding of the effects of ploidy on the early development of teleosts and provide knowledge about target genes and networks to improve the survival rate of haploids.
Waves play a major role in the ocean phenomena in the Gulf of Guinea (GoG). In order to reveal the spatial-temporal distribution characteristics and the propagation mechanism of waves from the South ...Atlantic Ocean to the GoG, 4 typical points located in mid-latitude of South Atlantic (14°30′W, 30°0′S), south of the GoG (10°30′W, 15°0′S), offshore of the GoG (0°0′, 0°0′) and near shore of the GoG (6°4′58.8″W, 4°3′36″S) are selected, and waves from Atlantic Ocean to GoG are simulated by using a two-layer-nesting wave numerical model SWAN (Simulating Waves Nearshore). The results show that the hybrid waves (waves hereafter) and the swells have strong relationship with local wind in Roaring Forties and at mid-latitude of South Atlantic Ocean, while there is no obvious correlation between waves and local winds in the GoG. Swells are generated in the South Atlantic Ocean and propagate into the GoG. 2D wave spectra at the four selected typical points are simulated. The spectral pattern and wave component structure indicate that the wave system in GoG is dominated by the S–SW swells generated from Roaring Forties and mid-latitude of South Atlantic, whether it is at maximum (2.2–2.8 m), medium (1.8–2.2 m) or minimum (1.2 m) significant wave height in the GoG during simulation period.
Tumor antigenicity and efficiency of antigen presentation jointly influence tumor immunogenicity, which largely determines the effectiveness of immune checkpoint blockade (ICB). However, the role of ...altered antigen processing and presentation machinery (APM) in breast cancer (BRCA) has not been fully elucidated.
A series of bioinformatic analyses and machine learning strategies were performed to construct APM-related gene signatures to guide personalized treatment for BRCA patients. A single-sample gene set enrichment analysis (ssGSEA) algorithm and weighted gene co-expression network analysis (WGCNA) were combined to screen for BRCA-specific APM-related genes. The non-negative matrix factorization (NMF) algorithm was used to divide the cohort into different clusters and the fgsea algorithm was applied to investigate the altered signaling pathways. Random survival forest (RSF) and the least absolute shrinkage and selection operator (Lasso) Cox regression analysis were combined to construct an APM-related risk score (APMrs) signature to predict overall survival. Furthermore, a nomogram and decision tree were generated to improve predictive accuracy and risk stratification for individual patients. Based on Tumor Immune Dysfunction and Exclusion (TIDE) method, random forest (RF) and Lasso logistic regression model were combined to establish an APM-related immunotherapeutic response score (APMis). Finally, immune infiltration, immunomodulators, mutational patterns, and potentially applicable drugs were comprehensively analyzed in different APM-related risk groups. IHC staining was used to assess the expression of APM-related genes in clinical samples.
In this study, APMrs and APMis showed favorable performances in risk stratification and therapeutic prediction for BRCA patients. APMrs exhibited more powerful prognostic capacity and accurate survival prediction compared to conventional clinicopathological features. APMrs was closely associated with distinct mutational patterns, immune cell infiltration and immunomodulators expression. Furthermore, the two APM-related gene signatures were independently validated in external cohorts with prognosis or immunotherapeutic responses. Potential applicable drugs and targets were mined in the APMrs-high group. APM-related genes were further validated in our in-house samples.
The APM-related gene signatures established in our study could improve the personalized assessment of survival risk and guide ICB decision-making for BRCA patients.
•The roles of grass components in reducing water erosion were quantified.•The runoff and sediment reduction were greatest in E. ophiuroides plot.•Grass cover had a greater impact on reducing sediment ...yield than overland flow.•Stolons played a dominant role in sediment reduction, with a contribution of 61%.
The influence of grass cover on surface runoff and erosion processes on hillslopes differs with plant morphology and grass components (e.g., leaves, stems and roots). However, the importance of grass components, especially stolons, in reducing runoff and sediment yield is not fully understood. Thirty field simulation experiments with rainfall intensities of 90 mm h−1 were performed to study the effects of three grass species (Trifolium repens, Cynodon dactylon and Eremochloa ophiuroides) and their aboveground and belowground components on runoff, hydrodynamic parameters and sediment reductions during rainstorms. To examine the effects of different grass components on soil erosion, three management treatments, intact grass plants (IG), grass stems and roots (SR) and only grass roots (OR), were applied to each grass species. The results showed that the three grass species effectively reduced runoff and soil erosion, and the erosion reduction was greater than the runoff reduction. The highest reduction in runoff (78.2%) and sediment yield (97.9%) was observed for E. ophiuroides, followed by the T. repens and C. dactylon plots. The overland flow velocity and runoff energy increased with the sequential removal of grass aboveground components and led to increasing runoff and erosion. The effects of grass components on runoff and erosion reduction varied with grass species and plant morphology. The aboveground components had a greater impact on runoff reduction, and the roots primarily contributed to sediment reduction in T. repens and C. dactylon, which have erect stems. However, the contribution rates of grass stems to runoff and erosion reduction were highest for E. ophiuroides with well-developed stolons at 41.51% and 61.04%, respectively, which were much higher than the leaves and roots. This finding indicated that grass stolons played an important role in reducing runoff and sediment with efficiencies of 32.44% and 59.79%, respectively. These results help guide the selection of grass species with the best traits for erosion control and highlight the importance of grass stolons in preventing water erosion caused by extreme rainstorms.
An analytical solution for long waves propagating over a submerged atoll is established. The atolls involved in this study are annular coral reefs with large lagoons in the middle, and the expression ...of the cross section is a trinomial function of the radial distance, i.e.,
h
=
ar
2
s
−
br
s
+
h
0
, where
s
is the positive rational number. This analytical solution extends the theory by Wang et al. (2018) as
s
is no longer limited to
s
=2/
m
, where
m
is the positive integer. In addition, by adjusting the terrain parameters properly, the analytic solution can be degenerated to describe the wave propagation over topography with a hump or pit. According to the relationship between wave rays and wave energy, the distribution characteristics and formation mechanism of energy over the topography are expounded. When the lagoon is non-existent, all wave rays converge at the
x
-axis, which results in an abrupt amplification of the wave amplitude around the convergence point. When a lagoon is mounted on the top of the atoll, the rays are scattered due to the refraction of the lagoon, and only some rays converge at the symmetrical axis and the ridges on both sides, which results in the amplification of wave amplitudes in these areas.
