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1.
Yilin Yang Siddarth K. Achar John R. Kitchin 《American Institute of Chemical Engineers》2022,68(6):e17653
The degree of rate control (DRC) quantitatively identifies the kinetically relevant (sometimes known as rate-limiting) steps of a complex reaction network. This concept relies on derivatives which are commonly implemented numerically, for example, with finite differences (FDs). Numerical derivatives are tedious to implement, and can be problematic, and unstable or unreliable. In this study, we demonstrate the use of automatic differentiation (AD) in the evaluation of the DRC. AD libraries are increasingly available through modern machine learning frameworks. Compared with the FDs, AD provides solutions with higher accuracy with lower computational cost. We demonstrate applications in steady-state and transient kinetics. Furthermore, we illustrate a hybrid local-global sensitivity analysis method, the distributed evaluation of local sensitivity analysis, to assess the importance of kinetic parameters over an uncertain space. This method also benefits from AD to obtain high-quality results efficiently. 相似文献
2.
Wei Lai Lihong Ge Huaming Li Yilin Deng Bin Xu Bo Ouyang Erjun Kan 《International Journal of Hydrogen Energy》2021,46(53):26861-26872
The electrochemical water splitting to produce H2 in high efficiency with earth-abundant-metal catalysts remains a challenge. Here, we describe a simple “cyclic voltammetry + ageing” protocol at room temperature to activate Ni electrode (AC-Ni/NF) for hydrogen evolution reaction (HER), by which Ni/Ni(OH)2 heterostructure is formed at the surface. In situ Raman spectroscopy reveals the gradual growth of Ni/Ni(OH)2 heterostructure during the first 30 min of the aging treatment and combined with polarization measurements, it suggests a positive relation between the Ni/Ni(OH)2 amount and HER performance of the electrode. The obtained AC-Ni/NF catalyst, with plentiful Ni–Ni(OH)2 interfaces, exhibits remarkable performance towards HER, with the low overpotential of only 30 mV at a H2-evolving current density of 10 mA/cm2 and 153 mV at 100 mA/cm2, as well as a small Tafel slope of 46.8 mV/dec in 1 M KOH electrolyte at ambient temperature. The excellent HER performance of the AC-Ni/NF could be maintained for at least 24 h without obvious decay. Ex situ experiments and in situ electrochemical-Raman spectroscopy along with density functional theory (DFT) calculations reveal that Ni/Ni(OH)2 heterostructure, although partially reduced, can still persist during HER catalysis and it is the Ni–Ni(OH)2 interface reducing the energy barrier of H1 adsorption thus promoting the HER performance. 相似文献
3.
Risk allocation decisions are of critical importance in project management. The present study proposes an explanation for how risk allocation in a contract motivates a contractor to cooperate with a project owner. Theories of risk allocation and trust were used to motivate the research. Using a survey methodology, we collected data concerning 124 construction projects in China. We found that risk allocation influenced the contractor’s role behavior through the contractor’s feeling of being trusted but not the contractor’s trust in the owner. Feeling of being trusted partially mediated the effect of risk allocation on the contractor’s in-role (i.e., contractual) behavior and fully mediated the effect on extra-role behavior. The study introduces a social and psychological view of the impacts of risk allocation to the project and engineering management literature. We contribute to theory by arguing and demonstrating the mediating effect of trust on the relationship between risk allocation and contractor behavior. From a practical standpoint, we conclude that contractual risk allocation has a significant impact on building a trusting relationship between owners and contractors and that contractors who feel trusted perform both contractually mandated actions and actions external to the contract more diligently, resulting in the likelihood of improved outcomes for both parties. 相似文献
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神经网络用于三元分子混合物密度与粘度的预测 总被引:5,自引:3,他引:2
以二元系实验为基础,利用反向转播算法训练神经网络,构造混合物组成,温度等与物性关系的模型,用于对4个三元混合物体系(1)邻二甲苯-间二甲苯-对二甲苯;(2)四氯化碳-环己烷-2-丙醇;(3)甲醇-丙酮-水;(4)水-甲醇-乙二醇的密度和5个三元混合物体系(1)信甲苯-间二甲苯-对二甲苯;(2)四氯化碳-环己烷-2-丙醇;(3)氯仿-2-丙醇-2-丁醇;(4)甲醇-丙酮-水;(5)乙醇-甲醇-水的粘 相似文献
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佳木斯造纸厂从芬兰奥斯龙公司引进了一套新型、高效、低碱流失的压力过滤、洗涤苛化系统。本文就如何延长该系统主体元件──滤套的使用寿命这一技术问题,进行系统的阐述。 相似文献
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主要介绍了自动化部近几年来在科技创新和管理方面的工作经验,如围绕莱钢生产建设全力推进技术创新;以“数字莱钢”建设为目标,加快推进莱钢信息化建设,所有这些都为莱钢提供了强有力的自动化信息化技术支撑。 相似文献