Mechanical modeling of incompressible particle-reinforced neo-Hookean composites based on numerical homogenization

In this paper, the mechanical response of incompressible particle-reinforced neo-Hookean composites (IPRNC) under general finite deformations is investigated numerically. Threedimensional Representative Volume Element (RVE) models containing 27 non-overlapping identical randomly distributed spheres are created to represent neo-Hookean composites consisting of incompressible neo-Hookean elastomeric spheres embedded within another incompressible neo-Hookean elastomeric matrix. Four types of finite deformation (i.e., uniaxial tension, uniaxial compression, simple shear and general biaxial deformation) are simulated using the finite element method (FEM) and the RVE models with periodic boundary condition (PBC) enforced. The simulation results show that the overall mechanical response of the IPRNC can be well-predicted by another simple incompressible neo-Hookean model up to the deformation the FEM simulation can reach. It is also shown that the effective shear modulus of the IPRNC can be well-predicted as a function of both particle volume fraction and particle/matrix stiffness ratio, using the classical linear elastic estimation within the limit of current FEM software

Circ_0008234 regulates the biological process of gallbladder carcinoma by targeting the miR-204-5p/FGFR2 axis

Background. Gallbladder carcinoma (GBC) is a common cancer disease with high mortality. Circular RNA_0008234 (circ_0008234) has been shown to play a key role in many tumors, including GBC. However, the function between circ_0008234 and microRNA-204-5p (miR-204-5p) in the progression of GBC has not been clarified. Methods. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expressions of circ_0008234, miR-204-5p and fibroblast growth factor receptor-2 (FGFR2) in GBC cells and tissues. Western blot was used to detect the expression of relative proteins. Cell proliferation, apoptosis, invasion and migration were detected by 3-(4, 5-dimethylthiazol2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay, thymidine analog 5-ethynyl-2’-deoxyuridine (EdU) assay, flow cytometry, transwell assay and wound healing assay. Mechanically, the interaction of miR-2045p with circ_0008234/FGFR2 was notarized by dualluciferase reporter assay. A xenotransplantation model was established to study the role of circ_0008234 in vivo. Results. Circ_0008234 and FGFR2 were highly expressed in GBC tissues and cells. Silencing circ_0008234 down-regulated cell proliferation, migration and invasion of NOZ and SGC-996 cells, while miR-204-5p inhibitors reversed these effects. In addition, overexpression of FGFR2 restored the cell malignant behavior of GBC cells inhibited by miR-2045p mimic. Animal experiments confirmed the anti-tumor effect of silenced circ_0008234 in vivo. Conclusion: Circ_0008234 mediated GBC via the miR-204-5p/FGFR2 axis, providing a novel targeted therapy for gallbladder carcinom

Range-Adaptive Wireless Power Transfer Based on Differential Coupling using Multiple Bi-directional Coils

Wireless power transfer systems using coupled magnetic resonances are susceptible to transfer position variation between the transmitter (Tx) and receiver (Rx). This is due to that the coupling between Tx and Rx is highly position-dependent. Once the transfer position deviates from the optimum one, the coupling will be either excessive or weak which results in power transfer efficiency (PTE) degradation. This paper presents a Tx structure consisting of multiple sub-coils oriented in opposite directions to keep the coupling relatively constant over an extensive range of transfer positions. The proposed design was able to achieve a PTE of 88% - 70% with transfer distance varying from 0 mm to 70 mm and a PTE of 85% - 60% with a misalignment of 0 mm – 80 mm at a 40 mm transfer distance. The radius of the Tx and Rx are 84.6 mm and 45.1 mm respectively. The measured PTE of the proposed design can be kept better than 70% with a 0 mm to 50 mm transfer distance while the misalignment changing from 0 mm to 50 mm. The performance of the system is much less sensitive to the transfer position, demonstrating a great potential in wireless charging applications

A novel Greenness and Water Content Composite Index (GWCCI) for soybean mapping from single remotely sensed multispectral images

As a critical source of food and one of the most economically significant crops in the world, soybean plays an important role in achieving food security. Large area accurate mapping of soybean has long been a vital, but challenging issue in remote sensing, relying heavily on large-volume and representative training samples, whose collection is time-consuming and inefficient, especially for large areas (e.g., national scale). Thus, methods are needed that can map soybean automatically and accurately from single-date remotely sensed imagery. In this research, a novel Greenness and Water Content Composite Index (GWCCI) was proposed to map soybean from just a single Sentinel-2 multispectral image in an end-to-end manner without employing training samples. By capitalizing on the product of the NDVI (related to greenness) and the short-wave infrared (SWIR) band (related to canopy water content), the GWCCI provides the required information with which to discriminate between soybean and other land cover types. The effectiveness of the proposed GWCCI was investigated in seven typical soybean planting regions within four major soybean-producing countries across the world (i.e., China, the United States, Brazil and Argentina), with diverse climates, cropping systems and agricultural landscapes. In the experiments, an optimal threshold of 0.17 was estimated and adopted by the GWCCI in the first study site (S1) in 2021, and then generalised to the other study sites over multiple years for soybean mapping. The GWCCI method achieved a consistently higher accuracy in 2021 compared to two conventional comparative classifiers (support vector machine (SVM) and random forest (RF)), with an average overall accuracy (OA) of 88.30% and a Kappa coefficient (k) of 0.77; significantly greater than those of RF (OA: 80.92%, k: 0.62) and SVM (OA: 80.29%, k: 0.60). Furthermore, the OA of the extended years was highly consistent with that of 2021 for study sites S2 to S7, demonstrating the great generalisation capability and robustness of the proposed approach over multiple years. The proposed GWCCI method is straightforward, reliable and robust, and represents an important step forward for mapping soybean, one of the most significant crops grown globally

Frequency analysis of urban runoff quality in an urbanizing catchment of Shenzhen, China

Copyright © 2013 Elsevier. NOTICE: this is the author’s version of a work that was accepted for publication in Journal of Hydrology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Hydrology Vol. 496 (2013), DOI: 10.1016/j.jhydrol.2013.04.053This paper investigates the frequency distribution of urban runoff quality indicators using a long-term continuous simulation approach and evaluates the impacts of proposed runoff control schemes on runoff quality in an urbanizing catchment in Shenzhen, China. Four different indicators are considered to provide a comprehensive assessment of the potential impacts: total runoff depth, event pollutant load, Event Mean Concentration, and peak concentration during a rainfall event. The results obtained indicate that urban runoff quantity and quality in the catchment have significant variations in rainfall events and a very high rate of non-compliance with surface water quality regulations. Three runoff control schemes with the capacity to intercept an initial runoff depth of 5 mm, 10 mm, and 15 mm are evaluated, respectively, and diminishing marginal benefits are found with increasing interception levels in terms of water quality improvement. The effects of seasonal variation in rainfall events are investigated to provide a better understanding of the performance of the runoff control schemes. The pre-flood season has higher risk of poor water quality than other seasons after runoff control. This study demonstrates that frequency analysis of urban runoff quantity and quality provides a probabilistic evaluation of pollution control measures, and thus helps frame a risk-based decision making for urban runoff quality management in an urbanizing catchment.Open Research Fund Program of State Key Laboratory of Hydroscience and EngineeringNational Natural Science Foundation of ChinaNational Water Pollution Control and Management Technology Major Project