Scaling Analysis of the Tensile Strength of Bamboo Fibers Using Weibull Statistics

This study demonstrates the effect of weak-link scaling on the tensile strength of bamboo fibers. The proposed model considers the random nature of fiber strength, which is reflected by using a two-parameter Weibull distribution function. Tension tests were performed on samples that could be scaled in length. The size effects in fiber length on the strength were analyzed based on Weibull statistics. The results verify the use of Weibull parameters from specimen testing for predicting the strength distributions of fibers of longer gauge lengths

Modified Weibull Distribution for Analyzing the Tensile Strength of Bamboo Fibers

There is growing evidence that the standard Weibull strength distribution is not always accurate for the description of variability in tensile strength and its dependence on the gauge size of brittle fibers. In this work, a modified Weibull model by incorporating the diameter variation of bamboo fiber is proposed to investigate the effect of fiber length and diameter on the tensile strength. Fiber strengths are obtained for lengths ranging from 20 to 60 mm and diameters ranging from 196.6 to 584.3 μm through tensile tests. It is shown that as the within-fiber diameter variation increases, the fracture strength of the bamboo fiber decreases. In addition, the accuracy of using weak-link scaling predictions based on the standard and modified Weibull distribution are assessed, which indicates that the use of the modified distribution provides better correlation with the experimental data than the standard model. The result highlights the accuracy of the modified Weibull model for characterizing the strength and predicting the size dependence of bamboo fiber

Study on the Hydration and Microstructure of B and B/Na Ion-Doped Natural Hydraulic Lime Composed with Silica Fume/Fly Ash

Natural hydraulic lime (NHL) has drawn much attention due to its environmentally friendly nature. The characteristics of both hydraulic and pneumatic components make it a potential substitute for Portland cement in surface decoration and ancient building restoration. In this study, both doping and mixing with supplementary cementitious materials were investigated. Two types of NHL3.5 were fabricated through calcination at 1200 °C with B and B/Na doping, respectively. It is noted that B ion doping is beneficial to the early compressive strength of the specimens, and B/Na doping is beneficial to the later compressive strength of the specimens. The observed outcome is that the compressive strengths of B and coupled B/Na doped NHL3.5 are higher than the blank sample due to the appearance of α’-C2S. Thereafter, the blank and doping NHL were incorporated with fly ash and silica fume. The incorporation of fly ash and silica fume could enhance the early and late hydration rate. Of the two, silica fume shows more pozzolanic effect in the early age. In the supplementary cementitious materials dosed group, pozzolanic dominates the hydration process

Mass Production of 3D Connective Graphene Networks by Fluidized Bed Chemical Vapor Deposition and Its Application in High Performance Lithium-Sulfur Battery

Three−dimensional (3D) graphene with novel nano−architectures exhibits many excellent properties and is promising for energy storage and conversion applications. Herein, a new strategy based on the fluidized bed chemical vapor deposition (FB−CVD) process was proposed to prepare 3D graphene networks (3DGNs) with various nano−architectures. Specially designed SiC−C@graphene core/shell nanoparticles were prepared taking the advantages of the FB−CVD system, and 3DGNs with hierarchical nanostructures were obtained after removing the SiC core. The 3DGNs performed well as electrodes of lithium–sulfur batteries. The C–S cathode showed good rate performance at the current density of 0.1–2.0 C, and an initial discharge capacity of 790 mAhg−1 cathode was achieved at a current density of 0.2 C. The Li−S batteries showed stabilized coulombic efficiency as high as 94% and excellent cyclic performance with an ultra low cyclic fading rate of 0.075% for the initial 280 cycles at a current density of 1.0 C. The improved electrochemical performance was ascribed to the enhanced conductivity by the connective graphene networks and the weakened shuttle effect by the special outer graphene layers. Mass production of the products was realized by the continuous FB−CVD process, which opens up new perspectives for large scale application of 3D graphene materials

Evaluation of AMSR-E retrieval by detecting soil moisture decrease following massive dryland re-vegetation in the Loess Plateau, China

Knowledge of soil moisture, however varied in space and time, is critical for planning land use in water-limited drylands. Although satellite observations provide soil moisture instantaneously at large scale, few studies have addressed the application of satellite soil moisture retrieval in dryland areas with changing land use. In this study, we propose a method to evaluate the spatiotemporal variance of satellite retrieval based on the evaluation of soil moisture retrievals from the Advanced Microwave Scanning Radiometer on the Earth Observing System (AMSR-E). The operation period of this instrument (June 2002 to October 2011) covers the re-vegetation of the semi-arid Loess Plateau. Our study found that AMSR-E retrievals posted by the Japanese Aerospace Exploration Agency (JAXA) capture the spatiotemporal variance of soil moisture in the Loess Plateau, as well as the in-situ measured soil moisture decrease following the massive re-vegetation-despite it differing from the in-situ measurement in spatial scale. Soil moisture decrease in response to the massive re-vegetation occurred in a transition zone of grass-forest ecosystems with annual precipitation between 450 and 550 mm. Our study suggests that current AMSR-E JAXA retrievals are an essential alternative to field measurement and model simulation, because they can identify the location and spatial extent of areas where soil moisture is sensitive to climate change and managed re-vegetation. To avoid the overconsumption of soil water and limited plant growth in transition zone, managers of dryland areas should pay special attention to species selection. (C) 2017 Elsevier Inc. All rights reserved

Software Tools for 2D Cell Segmentation

Cell segmentation is an important task in the field of image processing, widely used in the life sciences and medical fields. Traditional methods are mainly based on pixel intensity and spatial relationships, but have limitations. In recent years, machine learning and deep learning methods have been widely used, providing more-accurate and efficient solutions for cell segmentation. The effort to develop efficient and accurate segmentation software tools has been one of the major focal points in the field of cell segmentation for years. However, each software tool has unique characteristics and adaptations, and no universal cell-segmentation software can achieve perfect results. In this review, we used three publicly available datasets containing multiple 2D cell-imaging modalities. Common segmentation metrics were used to evaluate the performance of eight segmentation tools to compare their generality and, thus, find the best-performing tool

Bombus (Alpigenobombus) grahami Frison

68. <i>Bombus</i> (<i>Alpigenobombus</i>) <i>grahami</i> (Frison) <p>(Figs 138, 139)</p> <p> <i>Bremus (Alpigenobombus) grahami</i> Frison, 1933:334.</p> <p> <b>Material examined.</b> 12 workers, 2 males (IAB).</p> <p> <b>Distribution in North China.</b> Only in the Qin-Ba mountains in southern Gansu and southern Shaanxi. Rare at medium elevations of the Maijishan forest park and the Baishuijiang nature reserve in Gansu, at medium elevations of the Zhouzhi nature reserve, the Taibai nature reserve, and the Niubeiliang nature reserve in Shaanxi. 7 localities (Fig. 138) between 1284–2026 m (IAB).</p> <p> <b>Distribution in China.</b> Chongqing, Sichuan, Yunnan, Shaanxi, Gansu (IAB).</p> <p> <b>Forage plants.</b> ASTERACEAE: <i>Cirsium leo</i>, <i>Cosmos bipinnatus</i>; BUDDLEJACEAE: <i>Buddleja officinalis</i>; RANUNCULACEAE: <i>Anemone tomentosa</i>.</p>Published as part of <i>An, Jiandong, Huang, Jiaxing, Shao, Youquan, Zhang, Shiwen, Wang, Biao, Liu, Xinyu, Wu, Jie & Williams, Paul H., 2014, The bumblebees of North China (Apidae, Bombus Latreille), pp. 1-89 in Zootaxa 3830 (1)</i> on page 69, DOI: 10.11646/zootaxa.3830.1.1, <a href="http://zenodo.org/record/286560">http://zenodo.org/record/286560</a&gt