关键词： Sprayed concrete   Fibre-reinforced concrete   Flexural beam test   DPT test   DEWS test  

摘要： The flexural beam test EN 14488-3 is considered a reference for the characterization of the post-cracking tensile response of fibre-reinforced sprayed concrete (FRSC). However, the geometry of the specimens is a complication in case of characterising specimens extracted from the structure. The double punch test (DPT) and double-edge wedge splitting (DEWS) test are two alternative approaches that have been introduced to simplify the assessment of the post-cracking response of fibre-reinforced concrete. These tests could allow the characterisation of samples extracted from sprayed test panels or even existing structures. The objective of this experimental study is to demonstrate the possibility to correlate the flexural beam test EN 14488-3, the DPT and DEWS tests, and verify the capacity of these tests in predicting the constitutive model of FRSC. The results indicated high correlations (R-2 above 0.98) between tests. The constitutive models obtained from the alternative tests were close to those determined employing the flexural beam test. Both the DPT and DEWS test can replace the EN 14488-3 test in systematic quality control or for the confirmation of design parameters of FRSC structure. However, the DEWS test requires more time to prepare the specimens, being more appropriate to parameterize the constitutive models of the FRSC. The DPT, due to its simplicity of execution, becomes more practical for quality control of FRSC. Specimen with different size subjected to the DPT show a similar residual strength pattern. (C) 2021 Elsevier Ltd. All rights reserved.

关键词： Smooth particle hydrodynamics (SPH)   WENO reconstruction   Fully-discrete one-step ADER schemes   Meshfree Lagrangian particle method   Compressible Euler equations of gas dynamics   Magnetohydrodynamics  

摘要： We present a new class of fully-discrete one-step SPH schemes based on a mesh-free ADER (Arbitrary DERivatives in space and time) reconstruction on moving particles in multiple space dimensions. In particular, the new SPH scheme computes mesh-free and local high order accurate polynomials in space and time to evaluate numerical fluxes at the midpoint between two interaction particles with a proper Riemann solver within the general SPH framework of Vila (1999) for nonlinear systems of hyperbolic conservation laws. The new scheme has been carefully tested against reference solutions for both the compressible Euler and the magneto-hydrodynamics (MHD) equations. The capability of the proposed scheme to accurately capture shocks and rarefaction waves for 1D and 2D problems with minimal amount of diffusion has been demonstrated. Via numerical evidence it has been shown that the new fully-discrete one-step ADER-WENO-SPH method is computationally more efficient than WENO-SPH schemes based on classical Runge-Kutta time-stepping. This is mainly due to the fact that with ADER timestepping the expensive stencil and neighbor search needs to be done only once per time step, while with Runge-Kutta time integrators the neighbor and stencil search is needed in each Runge-Kutta stage again. (C) 2021 Elsevier B.V. All rights reserved.

关键词： Cobalt nanocatalyst   Green synthesis   Ocimum tenuiflorum   Artificial Neural Network   Modelling  

摘要： The present paper is dedicated to analyze non-hazardous kinetic behaviour and modelling of green synthesized cobalt nanocatalyst (CoNCs), using an Artificial Neural Network (ANN). In order to supplement the trace metal in other applications, CoNCs were rapidly synthesized with a Cobalt sulphate solution at room temperature between 30 and 35 oC at pH 7.2 under less reaction time. The Levenberg - Marquardt algorithm (LM) is used to investigate the experimental values by applying ANN. The results of variance using logistic ANN model depicts that the maximum nanoparticles were synthesized at its optimized stipulation of 0.5 h stirring time, 25 mL volume of extract and 20 mL volume of cobalt sulphate. The developed ANN model proved to be an efficient size determining tool in the biosynthesis of cobalt nanocatalyst. Experimental behavior using potentiometric analysis confirms that the linearity in CoNCs formation and size coincides (5-38 nm)with the predicted values of the ANN model. Techno economic analysis proved that, green synthesis reduced 30-40% in raw material cost and 60% in energy consumption.

关键词： Finite difference   Inviscid and viscous numerical examples   Monotone numerical flux   Multi-resolution WENO scheme   Unequal-sized central spatial stencil  

摘要： A new fifth-order alternative finite difference multi-resolution weighted essentially non-oscillatory (WENO) scheme is designed to solve the hyperbolic conservation laws in this paper. With the application of the original finite difference multi-resolution WENO schemes (Zhu and Shu, 2018;Zhu and Shu, 2020), a series of unequal-sized central spatial stencils are adopted to perform the WENO procedures, but the difference is that the methodology adopted in this paper is directly based on the point values of the solution rather than on the flux values. The proposed new multi-resolution WENO scheme can inherit many advantages of the original high order schemes, such as the arbitrary choice of the linear weights, the maintenance of the essentially non-oscillatory property in the vicinity of strong discontinuities, the smaller L-1 and L-infinity truncation errors than that of the same order classical WENOJS schemes (Balsara et al., 2016;Jiang and Shu, 1996) in smooth regions, and better convergence properties of the residue when solving some steady-state problems. Compared with the original multi-resolution WENO schemes, the presented WENO scheme also has some advantages. Firstly, an arbitrary monotone flux can be used in this framework, while the original method is only suitable for smooth flux splitting technique. Secondly, it has smaller L-1 and L-infinity truncation errors than that of the original same order multi-resolution WENO scheme. And finally, it avoids some time-consuming intermediate processes in the original multi-resolution WENO reconstruction procedures, thus resulting in less calculation time under the same conditions. Some inviscid and viscous numerical examples are provided to verify the superior performance of the new fifth-order alternative finite difference multi-resolution WENO scheme. (C) 2021 ElsevierB.V. All rights reserved.

摘要： Motivation:Alternative polyadenylation (APA) has been widely recognized as a widespread mechanism modulated dynamically. Studies based on 3' end sequencing and/or RNA-seq have profiled poly(A) sites in various species with diverse pipelines, yet no unified and easy-to-use toolkit is available for comprehensive APA analyses. Results: We developed an R package called movAPA for modeling and visualization of dynamics of alternative polyadenylation across biological samples. movAPA incorporates rich functions for preprocessing, annotation and statistical analyses of poly(A) sites, identification of poly(A) signals, profiling of APA dynamics and visualization. Particularly, seven metrics are provided for measuring the tissue-specificity or usages of APA sites across samples. Three methods are used for identifying 3' UTR shortening/lengthening events between conditions. APA site switching involving non-3' UTR polyadenylation can also be explored. Using poly(A) site data from rice and mouse sperm cells, we demonstrated the high scalability and flexibility of movAPA in profiling APA dynamics across tissues and single cells.

关键词： Skew-field of quaternions   Canonical forms   H-unitary  

摘要： The field of linear algebra over the quaternions is a research area which is still in development. In this paper we continue our research on canonical forms for a matrix pair (A, H), where the matrix Ais H-unitary, His invertible and with A as well as H quaternionic matrices. We seek an invertible matrix Ssuch that the transformations from (A, H) to (S(-1)AS, (SHS)-H-*) brings the matrix Ain Jordan form and simultaneously brings H into a canonical form. Canonical forms for such pairs of matrices already exist in the literature, the goal of the present paper is to add one more canonical form which specifically keeps Ain Jordan form, in contrast to the existing canonical forms. (C) 2020 The Author(s). Published by Elsevier Inc.

关键词： 他汀类降脂药物   联合用药   不良反应  

摘要： 目的 分析他汀类降脂药物联用其他类型药物后所致不良反应.方法 纳入2019年1月—2020年1月在我院接受药物治疗引起不良反应的44例患者作为研究对象患者,患者均接受他汀类降脂药物联用其他类型药物治疗,分析其临床不良反应情况、使用的他汀类降脂药物品种以及联合用药药物类型.结果 44例患者不良反应中,肌肉毒性、肝毒性分别有15例(34.09％)、12例(27.27％),占比最高,其次分别为消化系统不适(9.09％)、神经系统不适(9.09％)、呼吸系统不适(6.82％)、皮肤不适(4.55％)、泌尿系统不适(4.55％)以及其他(4.55％).使用的他汀类降脂药物中,辛伐他汀引起的不良反应最多,共21例,占比47.73％,其次分别为阿托伐他汀10例(22.73％)、瑞舒伐他汀6(13.64％)、氟伐他汀4例(9.09％)、普伐他汀3例(6.82％).联合用药类型中,抗心肌药或者降压药引起的不良反应发生率最高,共19例,占比43.18％,其次分别为抗凝类药物8例(18.18％)、降脂类药物8例(18.18％)、抗病毒类药物5(11.36％)、抗糖尿病类药物4例(9.09％).结论 他汀类降脂药物联用其他类型药物后最易引发肌肉毒性、肝毒性这两种不良反应,其中辛伐他汀与抗心肌药或者降压药联合使用更发生不良反应的几率更高.

摘要： 郭米 进入祁连县扎麻什乡郭米村时,首先是雪山吸引了我.一个一年四季都能看到雪山的人,见到雪山还要大惊小怪,有些不可思议,大约平时所见的雪山也不过是虾米级别的,此时的雪山才算雪山.路追着雪山走,路蜿蜒,或者笔直,雪山都蹲踞天边,岿然不动.路更像雪山甩出的鞭子,灰色细鞭抽在大地上,溅起的是庄廓、羊群和大片森林.可惜森林尚未变绿,草地还在枯黄,云杉的叶子看上去更像黑色的缝衣针.羊身上却是千干净净的白,刚洗过一样,小羊羔跟着羊妈妈啃草,也不知是真的啃还是学学样子.河流在公路一侧.这是黑河的下游,我们向西,河流向东.

关键词： Hybrid membranes   MOF-801   Proton exchange membranes   Structural defects   Sulfonated poly (arylene ether ketone sulfone)  

摘要： Metal-organic frameworks are new kinds of porous crystalline materials. The Zr-based metal-organic framework (MOF-801) is consists of [Zr-6(u(3)-O)(4)(u(3)-OH)(4)](12+) clusters and fumaric acid connectors. MOF-801 has excellent mechanical properties, high chemical stability and high water absorption capacity. There are a large number of hydrophilic functional groups inside MOF-801, which is effective to promote interfacial compatibility between MOF-801 and polymer matrixes. In this work, the MOF-801 with structural defects was synthesized through the solvothermal method by adding excess formic acids as the regulator. These structural defects could confer MOF-801 high surface area (2476.34 m(2) g(-1)) and promote the water absorption capacity. Moreover, structural defects could also expose more open metal sites of MOF-801, thereby increasing the Lewis acidity of MOF-801. Then, the hybrid membranes were synthesized by combining the MOF-801 with structural defects and C-SPAEKS. Dense hydrogen-bond networks formed between the MOF-801 and C-SPAEKS further promote enhance proton conductivity. At the condition of 90 degrees C and 100% relative humidity, the highest proton conductivity of hybrid membranes reached 0.100 S cm(-1), which is similar to that of Nafion 117. Meanwhile, these hybrid membranes showed outstanding chemical and thermal stabilities. These results indicate that these hybrid membranes have potential as proton exchange membranes. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.