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981.
Lihong Zhang Xiangyu Guo Shiping Huang 《International Journal of Hydrogen Energy》2021,46(53):26950-26960
By virtue of their wide band gaps, the photocatalytic ability of MnPS3 and ZnPS3 for water splitting is subject to narrow visible light adsorption. In this work, the first-principle calculations are adopted to study the impact of biaxial strain and electric field on photocatalytic performance of MnPS3 and ZnPS3. Our theoretical calculations demonstrate that MnPS3 under ?10% biaxial strain, ?5% biaxial strain and a 0.05 V/Å electric field possess appropriate band gaps and band edge positions required for photocatalytic water splitting as well as pronounced absorbance in the visible and ultraviolet spectrum. Whereas, the band structures for ZnPS3 can not be altered significantly either by applying biaxial strain or electric field. Through the free energy change analysis, it is found that water splitting reactions on MnPS3 under ?10% biaxial strain as well as ?5% biaxial strain can be thermodynamically spontaneous at pH 7–10 using natural sunlight. 相似文献
982.
《Geotextiles and Geomembranes》2022,50(2):216-230
Tensile strain development in high-density polyethylene (HDPE) geomembrane (GMB) liner systems in landfills was numerically investigated. A new constitutive model for municipal solid waste (MSW) that incorporates both mechanical creep and biodegradation was employed in the analyses. The MSW constitutive model is a Cam-Clay type of plasticity model and was implemented in the finite difference computer program FLAC?. The influence of the friction angle of the liner system interfaces, the biodegradation of MSW, and the MSW filling rate on tensile strains were investigated. Several design alternatives to reduce the maximum tensile strain under both short- and long-term waste settlement were evaluated. Results of the analyses indicate that landfill geometry, interface friction angles, and short- and long-term waste settlement are key factors in the development of tensile strains. The results show that long-term waste settlement can induce additional tensile strains after waste placement is complete. Using a HDPE GMB with a friction angle on its upper interface that is lower than the friction angle on the underlying interface, increasing the number of benches, and reducing the slope inclination are shown to mitigate the maximum tensile strain caused by waste placement and waste settlement. 相似文献
983.
《International journal for numerical methods in engineering》2018,115(7):791-824
A new solution approach, based on Tikhonov regularization on the Fredholm integral equations of the first kind, is proposed to find the approximate solutions of the strain softening problems. In this approach, the consistency condition is regularized with the Tikhonov stabilizers along with a regularization parameter, and the internal variable increments are solved from the resulting Euler's equations. It is shown that, as the regularization parameter is increased, the solutions converge to a unique one. A nonlocal yield condition and a nonlocal return mapping algorithm are proposed to carry out the integration of constitutive equations in the time and spatial domains. A global plastic dissipation principle is proposed to relax the classical local plastic dissipation postulate. Numerical examples show that the proposed approach leads to objective, mesh‐independent solutions of the softening‐induced localization problems. A comparison of the results from the proposed approach with those from the gradient‐dependent plasticity model shows that the two models give close solutions. 相似文献
984.
Traditional optimization methods, which take a specific order of modal frequency as the design constraint, could fail to obtain the desired solution because of modal substitution. An improved optimization model with continuous sizing variables is established to solve this problem, in which the minimum weight and a given local modal frequency are considered as the objective and the constraint. To capture accurately the expected mode of vibration, a local mode identification technique is proposed based on the strain energy ratio between the local area and the whole structure. With that scheme, an optimization system is developed, in which the local mode can be effectively identified and the constraint can be updated with it in the iteration process. Two numerical examples, of a reinforced plate and a satellite structure, are applied to illustrate the effectiveness and efficacy of the proposed method. 相似文献
985.
Binbin Chen Nicolas Gauquelin Daen Jannis Daniel M. Cunha Ufuk Halisdemir Cinthia Piamonteze Jin Hong Lee Jamal Belhadi Felix Eltes Stefan Abel Zoran Jovanović Matjaž Spreitzer Jean Fompeyrine Johan Verbeeck Manuel Bibes Mark Huijben Guus Rijnders Gertjan Koster 《Advanced materials (Deerfield Beach, Fla.)》2020,32(50):2004995
986.
Solid-state electrolytes (SSEs) are key to the success and reliability of all-solid-state lithium batteries, potentially enabling improvements in terms of safety and energy density over state-of-the-art lithium-ion batteries. However, there are several critical challenges to their implementation, including the interfacial instability stemming from the dynamic interaction of as-formed dendritic lithium during cycling. For this work, we emphasize the importance of studying the spatial distribution and temporal evolution of strains and defects in crystalline solid-state electrolytes at the micro-scale, and how this affects dendrite growth. A proof-of-principle study is demonstrated using the synchrotron radiation based micro Laue X-ray diffraction method, and a custom-developed in-situ cycling device. Defects and residual strains are mapped, and the evolution of intragranular misorientation is observed. The feasibility of using this technique is discussed, and recommendations for micro-strain engineering to address the Li/SSEs interfacial issues are given. Also, work directions are pointed out with the consideration of combining multi-techniques for “poly-therapy”. 相似文献
987.
针对在传统的客户流失预测数据预处理中,使用one-hot编码处理离散属性导致数据维度增加及数据过于稀疏的问题,提出了两种基于多层感知机的改进后的客户流失预测模型。其主要思想是分别使用堆叠自编码器和实体嵌入两种方法对多层感知机进行改进,通过将离散属性的高维编码数据向低维空间映射,有效地减少了one-hot编码产生的稀疏数据,增加了离散属性值之间的关联度。在对两份公开的数据集进行交叉验证后的实验结果表明,改进后的模型既有效地提高了预测的准确度,又维持了传统多层感知机模型在并行化计算方面的优势。 相似文献
988.
《Ceramics International》2019,45(11):14084-14089
Undoped and Cu-doped ZnSe nanoparticle (NPs) were prepared and grown hydrothermally in aqueous media assisted by microwave irradiation (MWIR) at different synthesis conditions of pH and MWIR times. In the mentioned process, sodium hydroxide (NaBH4), used for preparing selenium ions source with dissolving it and selenium powder in deionized water. To investigate the structural aspects and nanoparticles morphology, X-ray diffraction (XRD) and transmission electron microscopy (TEM) were used. According to the results of XRD, no displacement was seen in the position of XRD peaks of ZnSe nanoparticles by altering the pH and microwave irradiation time. XRD analysis demonstrated cubic zinc blende NPs and TEM images indicated round shape morphology of them. Depending to the microwave irradiation time, upon the XRD outputs, the size of the synthesized NPs were in the range of 1.54–2.18 nm. In this research, for samples synthesized at different pHs (= 8, 10.2, 11.2 and 12.2), at two microwave irradiation time of 0 and 6 min, and also at the presence of Cu-dopant (with the contents of 0, 0.1,0.75 and 1.5%), structural characteristics such as dislocation density(δ), lattice strain(ε), size of nanoparticles (D) and full width at half maximum (FWHM:βhkl) have been evaluated upon the Scherrer and Williamson-Hall methods, in which undoped and ZnSe:Cu 0.1% synthesized at pH = 11.2 have the best crystalline quality; such results for the optimum samples, introduce them as promising materials in optoelectronic devices. The results of structural features obtained from Scherrer and Williamson-Hall approaches are highly intercorrelated and show the same trends with the variation of synthesis conditions. 相似文献
989.
990.
For design of a geosynthetic-reinforced pile-supported (GRPS) embankment over soft soil, the methods used to calculate strains in geosynthetic reinforcement at a vertical stress were mostly developed based on a plane-strain or two-dimensional (2-D) condition or a strip between two pile caps. These 2-D-based methods cannot accurately predict the strain of geosynthetic reinforcement under a three-dimensional (3-D) condition. In this paper, a series of numerical models were established to compare the maximum strains and vertical deflections (also called sags) of geosynthetic reinforcement under the 2-D and 3-D conditions, considering the following influence factors: soil support, cap shape and pattern, and a cushion layer between cap and reinforcement. The numerical results show that the maximum strain in the geosynthetic reinforcement decreased with an increase of the modulus of subgrade reaction. The 2-D model underestimated the maximum strain and sag in the geosynthetic reinforcement as compared with the 3-D model. The cap shape and pattern had significant influences on the maximum strains in the geosynthetic reinforcements. An empirical method involving the geometric factors of cap shape and pattern, and the soil support was developed to convert the calculated strains of geosynthetic reinforcement in piled embankments under the 2-D condition to those under the 3-D condition and verified through a comparison with the results in the literature. 相似文献