Comercio electrónico conectando China y América Latina a través de la ruta de la seda digital

Latin America is the natural extension of the “Maritime Silk Road” and its exchanges and cooperation with China have become increasingly frequent in recent years. Under the current globale conomic backdrop, e-commerce as an emerging industry is gaining momentum and playing a bigger role in international  cooperation.  The  Belt  and  Road  top-level  design  features  policy  coordination, unimpededtrade, facilities connectivity and people-to-people bond respectively, which play a guiding role in China-LAC cooperation. Coupled with the status quo, the paper will mainly focus on these four sections so as to better analyze the China-LAC cooperation in Silk-Road E-commerce. This paper intends to analyze China-LAC e-commerce cooperation in fields of policy, trade, facilities, and people-to-people contact and study in which areas still remain room for bilateral cooperation and how can both sides better achieve win-win results under the framework of China’s “Belt and Road Initiative”.América Latina es la extensión natural de la “Ruta Marítima de la Seda” y sus intercambios y cooperación con China se han vuelto cada vez más frecuentes en los últimos años. En el contexto económico mundial actual, el comercio electrónico como industria emergente está cobrando impulso y desempeñando un papel más importante en la cooperación internacional. El diseño de alto nivel de la Franja y la Ruta presenta coordinación de políticas, comercio sin trabas, conectividad de instalaciones y vínculo entre personas, respectivamente, que desempeñan un papel rector en la cooperación entre China y ALC. Junto con el statu quo, el artículo se centrará principalmente en estas cuatro secciones para analizar mejor la cooperación entre China y ALC en el comercio electrónico de la Ruta de la Seda. Este documento tiene la intención de analizar la cooperación en comercio electrónico entre China y ALC en los campos de política, comercio, instalaciones y contacto entre personas y estudiar en qué áreas aún quedan espacios para la cooperación bilateral y cómo ambas partes pueden lograr mejores resultados en los que todos ganan en el marco de la “Iniciativa de la Franja y la Ruta” de China

Gabor-based audiovisual fusion for Mandarin Chinese speech recognition

Audiovisual Speech Recognition (AVSR) is a popular research topic, and incorporating visual features into speech recognition systems has been found to deliver good results. In recent years, end-to-end Convolutional Neural Network (CNN) based deep learning has been widely utilized. However, these often require big data and can be time consuming to train. A lot of speech research also tends to focus on English language datasets. In this paper, we propose a lightweight optimized and automated speech recognition system using Gabor based feature extraction, combined with our Audiovisual Mandarin Chinese (AVMC) corpus. This combines Mel-frequency Cepstral Coefficients (MFCCs) + CNN_Bidirectional Long Short-term Memory (BiLSTM)_Attention (CLA) model for Audio Speech Recognition, and low dimension Gabor visual features + CLA model for Visual Speech Recognition. As we are focusing on Chinese language recognition, we individually analyse initials, finals, and tones, as part of pinyin speech production. The proposed low dimensionality system achieves 88.6%, 87.5% and 93.6% accuracy for tones, initials and finals respectively at char-level, 84.8% for pinyin at word-level

Searching for biological feedstock material: 3D printing of wood particles from house borer and drywood termite frass

Frass (fine powdery refuse or fragile perforated wood produced by the activity of boring insects) of larvae of the European house borer (EHB) and of drywood termites was tested as a natural and novel feedstock for 3D-printing of wood-based materials. Small particles produced by the drywood termite Incisitermes marginipennis and the EHB Hylotrupes bajulus during feeding in construction timber, were used. Frass is a powdery material of particularly consistent quality that is essentially biologically processed wood mixed with debris of wood and faeces. The filigree-like particles flow easily permitting the build-up of wood-based structures in a layer wise fashion using the Binder Jetting printing process. The quality of powders produced by different insect species was compared along with the processing steps and properties of the printed parts. Drywood termite frass with a Hausner Ratio HR = 1.1 with ρBulk = 0.67 g/cm3 and ρTap = 0.74 g/cm3 was perfectly suited to deposition of uniformly packed layers in 3D printing. We suggest that a variety of naturally available feedstocks could be used in environmentally responsible approaches to scientific material sciences/additive manufacturing

Enhanced Microwave Absorption and Electromagnetic Properties of Si-Modified rGO@Fe3O4/PVDF-co-HFP Composites

Graphene has been regarded as one of the most promising two-dimensional nanomaterials. Even so, graphene was still faced with several key issues such as impedance mismatching and narrow bandwidth, which have hindered the practical applications of graphene-based nanocomposites in the field of microwave absorption materials. Herein, a series of Si-modified rGO@Fe3O4 composites were investigated and fabricated by a simple method. On one hand, the degree of defects in graphene carbon could be tuned by different silane coupling reagents, which were beneficial to enhancing the dielectric loss. On the other hand, the spherical Fe3O4 nanoparticles provided the magnetic loss resonance, which contributed to controlling the impedance matching. Subsequently, the electromagnetic absorption (EMA) properties of Si-modified rGO@Fe3O4 composites with poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-co-HFP) were investigated in this work. As a result, the Si(2)-rGO@Fe3O4/PVDF-co-HFP composite exhibited the excellent EMA performance in the range of 2–18 GHz. The maximum reflection loss (RLmax) reached −32.1 dB at 3.68 GHz at the thickness of 7 mm and the effective absorption frequency bandwidth for reflection loss (RL) below −10 dB was 4.8 GHz at the thickness of 2 mm. Furthermore, the enhanced absorption mechanism revealed that the high-efficiency absorption performance of Si(2)-rGO@Fe3O4/PVDF-co-HFP composite was attributed to the interference absorption (quarter-wave matching model) and the synergistic effects between Si(2)-rGO@Fe3O4 and PVDF-co-HFP. This work provides a potential strategy for the fabrication of the high-performance EMA materials

The reliability, correlation with clinical symptoms and surgical outcomes of dural sac cross-sectional area, nerve root sedimentation sign and morphological grade for lumbar spinal stenosis

Abstract Background No study had directly compared the reliability, correlation with clinical symptoms, and surgical outcomes of dural sac cross-sectional area (DCSA), nerve root sedimentation sign (SedSign), and morphological grade for lumbar spinal stenosis (LSS). Methods From January 2017 to December 2020, 202 patients with LSS were retrospectively analyzed. The narrowest segments were assessed via T2-weighted cross-sectional images using DCSA, morphological grade, and SedSign by two independent observers. Three classifications’ reliabilities were evaluated. Correlations between three classifications and between each of the classifications and symptoms or surgical outcomes 12 months postoperatively were evaluated. Results There were 144 males and 58 females; 23, 52, and 127 patients had the narrowest segment in L2–3, L3–4, and L4–5, respectively. The intra-observer reliability of DCSA ranged from 0.91 to 0.93, and the inter-observer reliability was 0.90. The intra-observer reliability of SedSign ranged from 0.83 to 0.85, and the inter-observer reliability was 0.75. The intra-observer reliability of morphological grade ranged from 0.72 to 0.78, and the inter-observer reliability was 0.61. Each of these classifications was correlated with the other two (P < 0.01). For preoperative symptoms, DCSA was correlated with leg pain (LP) (r =  − 0.14), Oswestry Disability Index (ODI) (r =  − 0.17), and claudication (r =  − 0.19). Morphological grade was correlated with LP (r = 0.19) and claudication (r = 0.27). SedSign was correlated with ODI (r = 0.23). For postoperative outcomes, morphological grade was correlated with LP (r =  − 0.14), and SedSign was correlated with ODI (r = 0.17). Conclusions Substantial to almost perfect intra and inter-observer reliabilities for the three classifications were found; however, these classifications had either weak correlations with symptoms and surgical outcomes or none at all. Based on our findings, using one of them without conducting other tests for LSS will have limited or uncertain value in surgical decision-making or evaluating the prognostic value

Numerical study on gas temperature and smoke control in blind roadway fires

In this study, smoke movement characteristics and smoke temperature in the blind roadway and the connected main roadway were mainly investigated numerically. The outcomings indicate that as the fire source gradually moves away from the heading face, the flame tilts from the heading face to the portal of the blind roadway. The gas temperature in the blind roadway and the downstream of the main roadway during ventilation is higher than that in the situation without ventilation, and it depends only on the fire location. The high-temperature smoke will generate energy loss as it passed through the bifurcation structure, resulting in a sudden decline in the longitudinal temperature attenuation curve. In addition, blind roadway fires require a higher critical velocity than single-hole tunnel fires. For a given heat release rate, the critical velocity gradually decreases as the fire source approaches the heading face. Besides, the line of L*=1.5 divides the variation of the dimensionless variable Q˙*2/3/v*2 with the dimensionless backlayering length (L*) into two regions with different slopes. Moreover, prediction models take into account the fire location to predict the dimensionless backlayering length and dimensionless critical velocity of the blind roadway are proposed