Exploring the geography of China's airport networks: a hybrid complex-network approach

Air networks are normal examples of transportation systems among ubiquitous big data networks in the dynamic nature. This is particularly the case in developing countries with rapid airport network expansions. This paper explores the structure and evolution of the trunk airport network of China (ANC) in major years during 1980s-2000s. We generalise the complex network approach developed in existing studies and further test for statistical properties of weighted network characteristics by using pair-wise traffic flows. The spatiotemporal decomposition of network metric plots and the visualization maps leads to a rich harvest of stylized ANC structures: (i) national hub-and-spoke patterns surrounding mega-cities; (ii) regional broker patterns surrounding Kunming and Urumqi, and (iii) local heterogeneous disparity patterns in isolated geographical cities, such as Lhasa, Lijiang, Huangshan, etc. These findings have important implications towards understanding the geo-political and economic forces at stake in shaping China's urban systems

Mechanism of shale oil displacement by CO2 in nanopores: A molecular dynamics simulation study

Utilizing CO2 to enhance shale oil recovery has a huge potential and thus has gained widespread popularity in recent years. However, the microscopic mechanisms of CO2 enhancing shale oil recovery remain poorly understood. In this paper, the molecular dynamics simulation method is adopted to investigate the replacement behavior of CO2 in shale oil reservoirs from a micro perspective. Three kinds of n-alkanes are selected as the simulative crude oil in silica nanopores. Molecular dynamics models are established to study the occurrence patterns of different alkanes on the rock surface and the alkane[1]stripping characteristics of CO2. The fluid density, mean square displacement and centroid variation are evaluated to reveal the effect of CO2 on alkanes. The results indicate that different alkanes exhibit varying occurrence characteristics of oil film on the rock surface of the shale reservoir. Specifically, a higher carbon number leads to a thicker oil film. Through the alkane molecular gaps, CO2 penetrates the alkane molecular system and reaches the rock surface to effectively strip the oil film of different alkane molecules. CO2 will more readily mix with the stripped oil molecules and displace them from the rock surface when the carbon number is small. The process for CO2 replacing crude oil on the rock surface can be divided into four typical stages, namely, CO2 diffusion, competitive adsorption, emulsification and dissolution, and CO2-alkanes miscible phase (for light alkanes). This study contributes to the improvement of micro-scale enhanced oil recovery mechanisms for shale oil via CO2 injection and provides a guidance for enhancing shale oil recovery by using CO2.Document Type: Original articleCited as: Wu, Z., Sun, Z., Shu, K., Jiang, S., Gou, Q., Chen, Z. Mechanism of shale oil displacement by CO2 in nanopores: A molecular dynamics simulation study. Advances in Geo-Energy Research, 2024, 11(2): 141-151. https://doi.org/10.46690/ager.2024.02.0

Monitoring coalescence behavior of soft colloidal particles in water by small-angle light scattering

The fractal dimension (D f) of the clusters formed during the aggregation of colloidal systems reflects correctly the coalescence extent among the particles (Gauer et al., Macromolecules 42:9103, 2009). In this work, we propose to use the fast small-angle light scattering (SALS) technique to determine the D f value during the aggregation. It is found that in the diffusion-limited aggregation regime, the D f value can be correctly determined from both the power law regime of the average structure factor of the clusters and the scaling of the zero angle intensity versus the average radius of gyration. The obtained D f value is equal to that estimated from the technique proposed in the above work, based on dynamic light scattering (DLS). In the reaction-limited aggregation (RLCA) regime, due to contamination of small clusters and primary particles, the power law regime of the average structure factor cannot be properly defined for the D f estimation. However, the scaling of the zero angle intensity versus the average radius of gyration is still well defined, thus allowing one to estimate the D f value, i.e., the coalescence extent. Therefore, when the DLS-based technique cannot be applied in the RLCA regime, one can apply the SALS technique to monitor the coalescence extent. Applicability and reliability of the technique have been assessed by applying it to an acrylate copolymer colloi

Trmt112 Gene Expression in Mouse Embryonic Development

Mouse Trmt112, the homologous gene of yeast Trm112 (tRNA methyltransferase 11-2), was initially cloned from RIKEN with uncertain function. The yeast TRM112 is now known to play important roles in RNA methylation. Here, we studied the expression of Trmt112 by in situ hybridization and quantitative real-time RT-PCR (QRT-PCR). A higher expression level of Trmt112 was observed in the brain and nervous system by whole mount in situ hybridization from embryonic day 10.5 (E10.5) to E11.5. At later developmental stages E13.5 and E16.5, abundant expression was prominently found in various organs and tissues including developing brain, nervous system, thymus, lung, liver, intestine, kidney, and cartilage. Furthermore, Trmt112 was persistently expressed from E9.5 to E18.5 on whole embryos and highly expressed in multiple organs at E12.5, E15.5 and E18.5 by QRT-PCR. These results showed that Trmt112 gene was highly and ubiquitously expressed during mouse embryonic development, implying that it might be involved in the morphogenesis of diverse organs and tissues and numerous physiological functions

Esophageal pressure monitoring and its clinical significance in severe blast lung injury

BackgroundThe incidence of blast lung injury (BLI) has been escalating annually due to military conflicts and industrial accidents. Currently, research into these injuries predominantly uses animal models. Despite the availability of various models, there remains a scarcity of studies focused on monitoring respiratory mechanics post-BLI. Consequently, our objective was to develop a model for monitoring esophageal pressure (Pes) following BLI using a biological shock tube (BST), aimed at providing immediate and precise monitoring of respiratory mechanics parameters post-injury.MethodsSix pigs were subjected to BLI using a BST, during which Pes was monitored. We assessed vital signs; conducted blood gas analysis, hemodynamics evaluations, and lung ultrasound; and measured respiratory mechanics before and after the inflicted injury. Furthermore, the gross anatomy of the lungs 3 h post-injury was examined, and hematoxylin and eosin staining was conducted on the injured lung tissues for further analysis.ResultsThe pressure in the experimental section of the BST reached 402.52 ± 17.95 KPa, with a peak pressure duration of 53.22 ± 1.69 ms. All six pigs exhibited an anatomical lung injury score ≥3, and pathology revealed classic signs of severe BLI. Post-injury vital signs showed an increase in HR and SI, along with a decrease in MAP (p < 0.05). Blood gas analyses indicated elevated levels of Lac, CO2-GAP, A-aDO2, HB, and HCT and reduced levels of DO2, OI, SaO2, and OER (p < 0.05). Hemodynamics and lung ultrasonography findings showed increased ELWI, PVPI, SVRI, and lung ultrasonography scores and decreased CI, SVI, GEDI, and ITBI (p < 0.05). Analysis of respiratory mechanics revealed increased Ppeak, Pplat, Driving P, MAP, PEF, Ri, lung elastance, MP, Ptp, Ppeak − Pplat, and ΔPes, while Cdyn, Cstat, and time constant were reduced (p < 0.05).ConclusionWe have successfully developed a novel respiratory mechanics monitoring model for severe BLI. This model is reliable, repeatable, stable, effective, and user-friendly. Pes monitoring offers a non-invasive and straightforward alternative to blood gas analysis, facilitating early clinical decision-making. Our animal study lays the groundwork for the early diagnosis and management of severe BLI in clinical settings

Prominent Size Effects without a Depolarization Field Observed in Ultrathin Ferroelectric Oxide Membranes

The increasing miniaturization of electronics requires a better understanding of material properties at the nanoscale. Many studies have shown that there is a ferroelectric size limit in oxides, below which the ferroelectricity will be strongly suppressed due to the depolarization field, and whether such a limit still exists in the absence of the depolarization field remains unclear. Here, by applying uniaxial strain, we obtain pure in-plane polarized ferroelectricity in ultrathin SrTiO3 membranes, providing a clean system with high tunability to explore ferroelectric size effects especially the thickness-dependent ferroelectric instability with no depolarization field. Surprisingly, the domain size, ferroelectric transition temperature, and critical strain for room-temperature ferroelectricity all exhibit significant thickness dependence. These results indicate that the stability of ferroelectricity is suppressed (enhanced) by increasing the surface or bulk ratio (strain), which can be explained by considering the thickness-dependent dipole-dipole interactions within the transverse Ising model. Our study provides new insights into ferroelectric size effects and sheds light on the applications of ferroelectric thin films in nanoelectronics

Integrative single-cell RNA sequencing and metabolomics decipher the imbalanced lipid-metabolism in maladaptive immune responses during sepsis

BackgroundTo identify differentially expressed lipid metabolism-related genes (DE-LMRGs) responsible for immune dysfunction in sepsis.MethodsThe lipid metabolism-related hub genes were screened using machine learning algorithms, and the immune cell infiltration of these hub genes were assessed by CIBERSORT and Single-sample GSEA. Next, the immune function of these hub genes at the single-cell level were validated by comparing multiregional immune landscapes between septic patients (SP) and healthy control (HC). Then, the support vector machine-recursive feature elimination (SVM-RFE) algorithm was conducted to compare the significantly altered metabolites critical to hub genes between SP and HC. Furthermore, the role of the key hub gene was verified in sepsis rats and LPS-induced cardiomyocytes, respectively.ResultsA total of 508 DE-LMRGs were identified between SP and HC, and 5 hub genes relevant to lipid metabolism (MAPK14, EPHX2, BMX, FCER1A, and PAFAH2) were screened. Then, we found an immunosuppressive microenvironment in sepsis. The role of hub genes in immune cells was further confirmed by the single-cell RNA landscape. Moreover, significantly altered metabolites were mainly enriched in lipid metabolism-related signaling pathways and were associated with MAPK14. Finally, inhibiting MAPK14 decreased the levels of inflammatory cytokines and improved the survival and myocardial injury of sepsis.ConclusionThe lipid metabolism-related hub genes may have great potential in prognosis prediction and precise treatment for sepsis patients

Bondlines in piezoelectric ultrasonic transducers

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Loss effects on adhesively-bonded multilayer ultrasonic transducers by self-heating

Multilayer ultrasonic transducers are widely being used for high power applications. In these applications, typical Langevin/Tonpilz structures without any adhesive bondings however have the disadvantage of limited bandwidth. Therefore adhesively-bonded structures are still a potential solution for this issue. In this paper, two-layer piezoelectric ceramic ultrasonic transducers with two different adhesive bondlines were investigated comparing to a single-layer transducer in terms of loss effects during operation with excitation signals sufficient to cause self-heating. The theoretical functions fitted to the measured time–temperature dependency data are compared with experimental results of different piezoelectric transducers. Theoretical analysis of loss characteristics at various surface displacements and the relationship with increasing temperature are reported. The effects of self-heating on the practical performance of multilayer ultrasonic transducers with adhesive bondlines are discussed