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1.
This paper focuses on the configuration design of flexure hinges with a prescribed compliance matrix and preset rotational center position. A new method for the topology optimization of flexure hinges is proposed based on the adaptive spring model and stress constraint. The hinge optimization model is formulated by maximizing the bending displacement with a spring while optimizing the compliance matrix to a prescribed value. To avoid numerical instability, an artificial spring is used as an auxiliary calculation, and a new strategy is developed for adaptively adjusting the spring stiffness according to the prescribed compliance matrix. The maximum stress of flexure hinge is limited by using a normalized P-norm of the effective von Mises stress, and a position constraint of rotational center is proposed to predetermine the position of the rotational center. In addition, to reduce the error of the stress measurement, a simple but effective filtering method is presented to obtain a complete black-and-white design. Numerical examples are used to verify the proposed method. Topology results show that the obtained flexure hinges have the prescribed compliance matrix and preset rotational center position while also meeting the stress requirements. 相似文献
2.
3.
This study proposes a multiperiod mixed integer linear programming model for the management of a single municipal solid waste (MSW) treatment plant with sustainability as the objective. Discrete and continuous variables define the capacity selections for diverse MSW technologies, and the operation of the MSW network, respectively. The economic target is considered to maximize the net present value. The environmental impact is the minimization of a normalized environmental objective function (NEOF). The social target is the maximization of jobs. An interesting feature about the research work is the requirement of biodrying technologies for MSW moisture content control. Due to the conflicted nature among the sustainability components, a multiobjective optimization (MO) is carried out to find the Pareto optimal solutions. The MO results show that the Pareto optimal solutions vary around profit range of $4.9–8.5 billion, NEOF impact range of 3.2–3.6 units, and social benefit range of 2700–4828 jobs. 相似文献
4.
Thomas R. Savage Fernando Almeida-Trasvina Ehecatl A. del-Rio Chanona Robin Smith Dondga Zhang 《American Institute of Chemical Engineers》2021,67(11):e17358
With liquefied natural gas becoming increasingly prevalent as a flexible source of energy, the design and optimization of industrial refrigeration cycles becomes even more important. In this article, we propose an integrated surrogate modeling and optimization framework to model and optimize the complex CryoMan Cascade refrigeration cycle. Dimensionality reduction techniques are used to reduce the large number of process decision variables which are subsequently supplied to an array of Gaussian processes, modeling both the process objective as well as feasibility constraints. Through iterative resampling of the rigorous model, this data-driven surrogate is continually refined and subsequently optimized. This approach was not only able to improve on the results of directly optimizing the process flow sheet but also located the set of optimal operating conditions in only 2 h as opposed to the original 3 weeks, facilitating its use in the operational optimization and enhanced process design of large-scale industrial chemical systems. 相似文献
5.
Xiaoping Guo Qiwen Pan Xiaoqian Song Qianyi Guo Shangxiong Zhou Jianrong Qiu Guoping Dong 《Journal of the American Ceramic Society》2021,104(2):886-895
Fluorescent detection is a new spectroscopic measurement for ions sensing due to the advantages of real-time determination with high selectivity, accuracy, and low cost. However, chemosensors based on fluorescent detection are usually determined by absolute intensity from a monochromatic emission signal, which is easy to be fluctuated by the external environment, especially for Fe3+ detection in complex fluids. Herein, we rationally design a dual-emission Eu3+: CDs@ZIF-8 to construct a ratiometric fluorescent sensor with self-calibrating ability for Fe3+ determination. High efficient carbon dots (CDs) are embedded in europium ions (Eu3+)-doped MOF by simple stirring preparation at room temperature. The label-free ratiometric fluorescent probe (ICDs@ZIF-8/IEu) exhibits simultaneous blue and red emission under the same excitation at 365 nm. Remarkably, Eu3+: CDs@ZIF-8 displays the superiority of high selectivity to Fe3+, which shows ratiometric fluorescence characteristics (I0/I) in a range of 0-6 μmol\L with a low limit of detection (LOD) of 0.897 μmol\L. Besides, the CDs-MOF nanocomposite holds good aqueous dispersibility and low cytotoxicity, which shows great potential applications in medical aid including biological detection and clinical diagnosis. 相似文献
6.
Zhiwei Qiao Lifeng Li Shuhua Li Hong Liang Jian Zhou Randall Q. Snurr 《American Institute of Chemical Engineers》2021,67(10):e17352
Computational screening was employed to calculate the enantioseparation capabilities of 45 functionalized homochiral metal–organic frameworks (FHMOFs), and machine learning (ML) and molecular fingerprint (MF) techniques were used to find new FHMOFs with high performance. With increasing temperature, the enantioselectivities for (R,S)-1,3-dimethyl-1,2-propadiene are improved. The “glove effect” in the chiral pockets was proposed to explain the correlations between the steric effect of functional groups and performance of FHMOFs. Moreover, the neighborhood component analysis and RDKit/MACCS MFs show the highest predictive effect on enantioselectivities among the four ML classification algorithms with nine MFs that were tested. Based on the importance of MF, 85 new FHMOFs were designed, and a newly designed FHMOF, NO2-NHOH-FHMOF, with high similarity to the optimal MFs achieved improved chiral separation performance, with enantioselectivities of 85%. The design principles and new chiral pockets obtained by ML and MFs could facilitate the development of new materials for chiral separation. 相似文献
7.
文中提出了一种利用有限数量的相量测量单元(PMU)和相量数据集中器(PDC)设计最优监控结构的方法。通过在大量的设定值场景下,使电力系统可观测性曲线的期望值最大化,同时使通信基础设施成本最小化,最终确定PMU和PDC的最佳位置。提出了一种非线性动态扩展卡尔曼滤波(EFK)状态观测器。这种状态观测器可以将暂态行为转换为由代数微分方程描述的广域电力系统,而无需非线性反演技术。最后以IEEE-5电力系统为例,说明了该方法的有效性。 相似文献
8.
9.
《International Journal of Hydrogen Energy》2022,47(14):8943-8955
In this research, a technical, economic and environmental analysis has been proposed to a Hybrid Solid Oxide Fuel Cell (SOFC) system-based hybrid system including biomass, gas turbine, and Proton Exchange Membrane Electrolyzer. A multi-objective optimization technique has been utilized to improve the overall product cost and the exergy effectiveness based on a developed version of Aquila Optimizer (DAO). The main idea of using the developed version is to improve the accuracy and the precision of the original Aquila optimizer. The system is then authenticated in terms of energy/exergy effectiveness, and energy-economic efficiency. The achievements indicate that employing the optimization algorithm for different configurations provided satisfying results for the system. 相似文献
10.
《International Journal of Hydrogen Energy》2022,47(87):37002-37012
The development of highly efficient nοn-nοble meta? catalysts for (ОRR) in PEMFCs is at the heart of the research, yet their performance is not satisfactory. The Fe–N active sites enclosed in carbon matrix are generally agreed to be the most promising active sites for ORR. In view of this, further effort is made to increase the Fe–N active sites. Here we present the fabrication of novel FeNi bimetallic electrоcatalyst obtained from ZIF, which consists of FeNi nanоallоys incorporated in N-doped carbon (FeNi-NC) featuring carbon nanotubes and porous carbon demonstrates outstanding results for ОRR. The Fe–N and Ni–N active sites synergistically enhance the ORR activity of FeNi-NC catalyst. The FeNi-NC showed remarkable performance in KОH with the half-wave and onset potential of 0.89 V and 0.99 V vs RHE, respectively. This catalyst shows exceptional stability in methanol equivalent to Pt/C commercial. The FeNi-NC retained 71%, while Pt/C commercial retained only 59% of its original current density. The exceptional stability and activity might be associated with the interplay among FeNi active sites and N-doped carbon, the distinct nanо-structure made up of porous carbon and carbon nanotubes with a high graphitization degree. 相似文献