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91.
《Ceramics International》2020,46(2):1396-1402
SnO2-based materials are deemed to be attractive electrodes for lithium/sodium ion batteries (LIBs and SIBs) and electrocatalytic CO2 reduction reaction (CRR) because of high energy density and large abundance. However, the practical application of the SnO2-based materials is prevented by low electrical conductivity and large volume change. Herein, we construct a three-dimensional (3D) porous network with SnO2 nanoparticles into N-doped carbon (namely P–SnO2@NC) synthesized by freeze drying followed by a pyrolyzation process. In the composite, the 3D hierarchical framework can facilitate the ion penetration and gas diffusion. In addition, the NC network can optimize the conductivity of the material and suppress the electrode material to fall off from the electrode. Therefore, the electrode delivers excellent electrochemical properties with high capacities of 510 mA h g−1 after 1000 cycles for LIBs and 497 mA h g−1 after 500 cycles for SIBs. Furthermore, the electrode shows high selectivity for CRR with a large coulombic efficiency (CE) of 52.7% for HCOOH at 0.6 V. 相似文献
92.
Shibendu Mahata Rajib Kar Durbadal Mandal 《International Journal of Circuit Theory and Applications》2020,48(9):1554-1560
In this letter, the optimal rational approximation of fractional-order bandpass Butterworth filter (FOBBF) is presented. The transfer function of the FOBBF is decomposed into a multiplication of first-order and second-order terms. As a result, the design stability conditions can be easily satisfied using only the variable boundary constraints. The proposed technique generalizes the symmetric fractional-order roll-off characteristic as only a special case of the asymmetric one. Several examples are presented to validate the modeling efficacy. 相似文献
93.
94.
Alternative selection in new product development (NPD) is a multi-criteria decision-making (MCDM) problem. It usually starts with incomplete, imprecise or even partially missing information. Currently, most existing methods in dealing with this problem cannot work well if required information is incomplete or missing. It is acknowledged that stochastic multi-objective acceptability analysis (SMAA) can be applied to address MCDM problem with incomplete preference information and uncertain criteria measurements. In SMAA, alternatives are evaluated based on SMAA measurements (acceptability index, central weight vector and confidence factor). The discriminability of SMAA for the optimum alternative heavily depends on differences of SMAA measurements among different alternatives. Usually, a large number of alternatives and high level of uncertainty are involved in alternative selection in NPD. In this situation, the differences among SMAA measurements are not obvious, and therefore SMAA cannot deal with such problem very well. To this end, this paper proposes an improved SMAA method called Iterative-SMAA (I-SMAA) for alternative selection in NPD. In the I-SMAA, an iterative multi-step decision-making process is suggested to improve differences of SMAA measurements among different alternatives, and thus assist decision makers (DMs) to positively discern from the most preferred alternative. To enhance the decision-making efficiency, sensitive criteria are acquired in each iteration by ranking sensitivity analysis. DMs are guided to provide partial preference information and give more accurate criteria measurements for sensitive criteria rather than all criteria. Eventually, to verify the proposed method, a numerical example of the existing literature is solved with the method, and the results are compared. And then, a practical example of a preparation equipment for coal samples is further employed to verify the practicability of the proposed I-SMAA. 相似文献
95.
96.
97.
Multiemotional product color design using gray theory and nondominated sorting genetic algorithm-III
When users select products, they consider the emotional experience resulting from the color of the product. However, the emotional demands of users for product color are multidimensional and diverse. It is very important yet difficult to accurately grasp multiemotional image requirements and effectively convert them into design elements. Therefore, multiemotional product color design (MEPCD) has become a very important and challenging research topic. In this article, a novel MEPCD system using gray theory (GT) and nondominated sorting genetic algorithm-III (NSGA-III) is proposed to effectively solve the MEPCD problem. First, the image perception spaces of users, which exist in different emotional dimensions, were collected using factor analysis and the semantic differential technique. Then, GT was used to establish a multidimensional emotional product color image evaluation model. Finally, NSGA-III was used to optimize and design a multiemotional color scheme for a product. Furthermore, according to actual conditions, an MEPCD system was established based on the proposed method. The design case study shows that the method and design system proposed in this article have a certain range of applicability and can effectively improve the practicality of MEPCD. 相似文献
98.
《International Journal of Hydrogen Energy》2020,45(38):19455-19464
This paper presents a new procedure for optimal allocation and optimal sizing of a battery energy storage system (BESS) for primary frequency support in an isolated power system. For the BESS allocation, a transmission bus system with larger frequency decline is recognized and the BESS sizing is performed by a constrained optimization strategy based on a new modified metaheuristic, called Developed Harris Hawks Optimization (DHHO). The simulation results of the suggested DHHO are compared with Bat Optimization Algorithm (BOA) and Genetic Algorithm (GA) from the literature to show the method efficiency. The final results showed higher precision with lower required iterations for the suggested DHHO method. Also, the proposed DHHO gives lower investment costs for BESS with lower power and energy requirement toward the other compared methods. 相似文献
99.
100.
乙烯裂解炉内复杂物理化学过程耦合模拟与优化能够满足乙烯装置对高效率、低污染和低成本的设计和操作要求,对提高乙烯工业的竞争力具有重要意义。针对简单燃烧机理难以准确预测炉膛燃烧生成NOx浓度分布的弊端,提出了在裂解炉使用更准确的简化GRI-Mesh 3.0机理结合涡耗散概念(EDC)模型的方法,并对Sandia Flame D的燃烧过程进行计算流体力学(CFD)模拟,验证了此耦合模型的可靠性。在已建立的燃烧模型的基础上,研究了助燃空气对降低裂解炉NO排放的影响,结果表明:在满足裂解炉热效率的情况下,空气预热温度为300~600 K、过量空气系数为1.1时降低NO的效果最佳。 相似文献