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Composition design of high-entropy alloys with deep sets learning

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npj Computational Materials 2022年第1期8卷 834-844页

作者： Jie Zhang chen cai George Kim Yusu Wang Wei chen Department of Mechanical Materialsand Aerospace EngineeringIllinois Institute of TechnologyChicagoIL60616USA Halıcıoğlu Data Science Institute University of California San DiegoLa JollaCA92093USA

High entropy alloys(HEAs)are an important material class in the development of next-generation structural materials,but the astronomically large composition space cannot be efficiently explored by experiments or first-principles *** learning(ML)methods might address this challenge,but ML of HEAs has been hindered by the scarcity of HEA property *** this work,the EMTO-CPA method was used to generate a large HEA dataset(spanning a composition space of 14 elements)containing 7086 cubic HEA structures with structural properties,1911 of which have the complete elastic tensor *** elastic property dataset was used to train a ML model with the Deep Sets *** Deep Sets model has better predictive performance and generalizability compared to other ML *** rule mining was applied to the model predictions to describe the compositional dependence of HEA elastic properties and to demonstrate the potential for data-driven alloy design.

关键词： alloys alloy entropy

From golden rice to a STARice, more than just two steps forward in a pathway

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Science China(Life Sciences) 2019年第2期62卷 280-281页

作者： Wei-cai chen Shan Lu State Key Laboratory of Pharmaceutical Biotechnology School of Life Sciences Nanjing University

Carotenoids are widely distributed in higher plants, algae and some bacteria and fungi. For human beings, they are essential phytonutrients that serve not only as precursors of vitamin A.

关键词： From golden rice to a STARice more than just two steps forward in a pathway

Direct electron transfer of glucose oxidase on the carbon nanotube electrode

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Science China Chemistry 2004年第2期47卷 113-119页

作者： cai chenxin chen Jing LU Tianhong Department of Chemistry Nanjing Normal University Nanjing 210097 China Department of Chemistry Nanjing Normal University Nanjing 210097 China Department of Chemistry Nanjing Normal University Nanjing 210097 China

The direct electron transfer of glucose oxidase (GOx) immobilized onto the surface of the carbon nanotube (CNT)-modified glassy carbon (CNT/GC) electrode is reported. The direct electron transfer rate of GOx is greatly enhanced when it was immobilized onto the surface of CNT/GC electrode. Cyclic voltammetric results show a pair of well-defined and nearly symmetric redox peaks, which corresponds to the direct electron transfer of GOx, with the formal potential (E 0′), which is almost independent on the scan rates, of about ?0.456 V (vs. SCE) in the phosphate buffer solution (pH 6.9). The apparent heterogeneous electron transfer rate constant (ks) of GOx at the CNT/GC electrode surface is estimated to be (1.74 ± 0.42) s-1, which is much higher than that reported previously. The dependence of E 0′ on solution pH indicates that the direct electron transfer of GOx is a two-electron-transfer coupled with two-proton-transfer reaction process. The experimental results also demonstrate that the immobilized GOx retains its bioelectrocatalytic activity toward the oxidation of glucose. The method presented here can be easily extended to obtain the direct electrochemistry of other enzymes or proteins.

关键词： carbon nanotube, chemically modified electrode, direct electrochemistry, bioelectrocatalysis, glucose oxidase, glucose.

Discrete Time Mean-variance Analysis with Singular Second Moment Matrixes and an Exogenous Liability

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Acta Mathematica Sinica,English Series 2008年第4期24卷 565-576页

作者： Wen cai chen Zhong Xing YE Department of Mathematics Nanchang University Nanchang 330031 P. R. China Department of Mathematics Shanghai Jiaotong University Shanghai 200240 P. R. China Department of mathematics Shanghai Jiaotong University Shanghai 200240 P. R. China

We apply the dynamic programming methods to compute the analytical solution of the dynamic mean-variance optimization problem affected by an exogenous liability in a multi-periods market model with singular second moment matrixes of the return vector of assets. We use orthogonai transformations to overcome the difficulty produced by those singular matrixes, and the analytical form of the efficient frontier is obtained. As an application, the explicit form of the optimal mean-variance hedging strategy is also obtained for our model.

关键词： mean-variance analysis exogenous liability singular second moment matrixes orthogonal transformations dynamic programming methods

Experimental investigation and prediction model for UCS loss of unsaturated sandstones under freeze-thaw action

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International Journal of Mining Science and Technology 2022年第1期32卷 41-49页

作者： Shibing Huang Yingbo He Shilin Yu chen cai School of Resources and Environmental Engineering Wuhan University of Science and TechnologyWuhan 430081China Hubei Key Laboratory for Efficient Utilization and Agglomeration of Metallurgic Mineral Resources Wuhan 430081China Shanghai Construction No.1(Group)Co. Ltd.Shanghai 200120China

Sandstone is widely distributed in cold regions and the freeze-thaw deterioration of them has caused many geological engineering *** an important and direct index of frost resistance,the strength loss of sandstones under freeze-thaw actions should be investigated to provide a guidance for the stability assessment of geological *** this research,the UCS(Uniaxial compressive strength)loss of six typical sandstones with different water contents after 0,20,40 and 60 freeze-thaw cycles was measured in the *** experimental results indicated that the freeze-thaw damage was more serious in sandstones containing high water contents,and the critical saturations for causing a significant loss of UCS under freeze-thaw were 60%-80%for these *** this critical saturation,the UCS loss of the sandstones was mainly caused by water weakening rather than freeze-thaw ***,a developed strength prediction model was proposed by combining the exponential decay function and multiple linear regression *** initial porosity,elastic modulus and tensile strength of fresh sandstones were a good parameter combination to accurately determine the decay constant in this developed *** main novelty of this model is that it can accurately and easily estimate the UCS loss of sandstones after any freeze-thaw cycle only using the initial parameters of fresh sandstones,but it does not need to perform freeze-thaw and mechanical strength *** study not only provides an accurate prediction model of UCS under freeze-thaw,but also makes a contribution to better understanding the frost resistance mechanism of sandstones.

关键词： Strength loss Freeze-thaw cycles Prediction model Decay constant Critical saturation

Lagrangian statistics in isotropic turbulent flows with deterministic and stochastic forcing schemes

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Acta Mechanica Sinica 2015年第1期31卷 25-31页

作者： Jin-cai chen Guo-Dong Jin Jian Zhang LNM Institute of MechanicsChinese Academy of Sciences

Artificial input of energy into the flow is neces sary to create and maintain a statistically stationary isotropic turbulence for sampling in studying the statistics. Due to the nonlinear coupling among different Fourier modes through the triadic interaction, whether or not various forc ing schemes affect the statistics in turbulence is an impor tant and open question. We present detailed comparison of Lagrangian statistics of fluids particles in forced isotropic turbulent flows in 1283, 2563, and 5123 simulations, with Taylorscale Reynolds numbers in the range of 64-171, us ing a deterministic and a stochastic forcing scheme, respec tively. Several Lagrangian statistics are compared, such as velocity and acceleration autocorrelations, and moments of Lagrangian velocity increments. The differences in the La grangian statistics obtained from the two forcing schemes are shown to be small, indicating that the isotropic forcing schemes used have little effects on the Lagrangian statistics in the isotropic turbulence.

关键词： Isotropic turbulence Deterministic forcingscheme Stochastic forcing scheme Lagrangian statisticalquantities

Developing“precise-acting”strategies for improving anaerobic methanogenesis of organic waste:Insights from the electron transfer system of syntrophic partners

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Frontiers of Environmental Science & Engineering 2022年第6期16卷 91-94页

作者： Lei Li Shijie Yuan chen cai Xiaohu Dai State Key Laboratory of Pollution Control and Resources Reuse School of Environmental Science and EngineeringTongji UniversityShanghai 200092China Shanghai Institute of Pollution Control and Ecological Security Shanghai 200092China

Methanogenesis is the last step in anaerobic digestion,which is usually a rate-limiting step in the biological treatment of organic *** low methanogenesis efficiency(low methane production rate,low methane yield,low methane content)substantially limits the development of anaerobic digestion *** pretreatment methods and bio-stimulation strategies have impacts on the entire anaerobic system and cannot directly enhance methanogenesis in a targeted manner,which was defined as“broad-acting”strategies in this ***,we discussed our opinion of methanogenesis process with insights from the electron transfer system of syntrophic partners and provided potential targeted enhancing strategy for high-efficiency electron transfer ***“precise-acting”strategies are expected to achieve an efficient methanogenesis process and enhance the bio-energy recovery of organic waste.

关键词： Methanogenesis Anaerobic digestion Enhancing strategy Electron transfer Organic waste

Synergistic antitumor activity of artesunate and HDAC inhibitors through elevating heme synthesis via synergistic upregulation of ALAS1 expression

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Acta Pharmaceutica Sinica B 2019年第5期9卷 937-951页

作者： cai-Ping chen Kun chen Zhiqi Feng Xiaoan Wen Hongbin Sun Jiangsu Key Laboratory of Drug Discovery for Metabolic Disease State Key Laboratory of Natural MedicinesChina Pharmaceutical University

Artemisinin and its derivatives(ARTs) were reported to display heme-dependent antitumor activity. On the other hand, histone deacetylase inhibitors(HDACi) were known to be able to promote heme synthesis in erythroid cells. Nevertheless, the effect of HDACi on heme homeostasis in nonerythrocytes remains unknown. We envisioned that the combination of HDACi and artesunate(ARS)might have synergistic antitumor activity through modulating heme synthesis. In vitro studies revealed that combination of ARS and HDACi exerted synergistic tumor inhibition by inducing cell death. Moreover, this combination exhibited more effective antitumor activity than either ARS or HDACi monotherapy in xenograft models without apparent toxicity. Importantly, mechanistic studies revealed that HDACi coordinated with ARS to increase 5-aminolevulinate synthase(ALAS1) expression, and subsequent heme production, leading to enhanced cytotoxicity of ARS. Notably, knocking down ALAS1 significantly blunted the synergistic effect of ARS and HDACi on tumor inhibition, indicating a critical role of ALAS1 upregulation in mediating ARS cytotoxicity. Collectively, our study revealed the mechanism of synergistic antitumor action of ARS and HDACi. This finding indicates that modulation of heme synthesis pathway by the combination based on ARTs and other heme synthesis modulators represents a promising therapeutic approach to solid tumors.

关键词： Artesunate HDAC inhibitor Heme ALAS1 Antitumor

Robust Nonsingular Fixed Time Terminal Sliding Mode Control for Atmospheric Pollution Detection Lidar Scanning Mechanism

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Journal of Systems Science & Complexity 2023年第2期36卷 500-523页

作者： KANG Yu YANG Yuxiao chen cai LüWenjun ZHAO Yunbo Department of Automation University of Science and Technology of ChinaHefei 230027China Institute of Advanced Technology University of Science and Technology of ChinaHefei 230027China State Key Laboratory of Fire Science University of Science and Technology of ChinaHefei 230027China

A robust nonsingular fixed time terminal sliding mode control scheme with a time delay disturbance observer is proposed for atmospheric pollution detection lidar scanning mechanism(APDL-SM)*** from the conventional terminal sliding mode control methods,the authors design a novel fixed-time terminal sliding surface,the convergence time of sliding mode phase of which has a constant upper bound that is designable by adjusting only one ***,in order to overcome the problem of unknown upper bound of lumped uncertainty including model uncertainty,friction effect and external disturbances from the port environment,the authors propose a time delay disturbance observer to provide an estimation for the system lumped *** using the Lyapunov synthesis,the explicit analysis of the convergence time upper bound are ***,simulation studies are conducted on the APDL-SM system to show the fast convergence rate and strong robustness of the proposed control scheme.

关键词： Atmospheric pollution detection lidar fixed time terminal sliding mode time delay disturbance observer tracking control