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Nonlinear dynamics in non-volatile locally-active memristor for periodic and chaotic oscillations

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Chinese Physics B 2020年第11期29卷 244-258页

作者： Wen-yu Gu Guang-Yi Wang yu-jiao dong Jia-Jie Ying Institute of Modern Circuits and Intelligent Information Hangzhou Dianzi UniversityHangzhou 310018China

Complexity and abundant dynamics may arise in locally-active systems only, in which locally-active elements are essential to amplify infinitesimal fluctuation signals and maintain oscillating. It has been recently found that some memristors may act as locally-active elements under suitable biasing. A number of important engineering applications would benefit from locally-active memristors. The aim of this paper is to show that locally-active memristor-based circuits can generate periodic and chaotic oscillations. To this end, we propose a non-volatile locally-active memristor, which has two asymptotically stable equilibrium points(or two non-volatile memristances) and globally-passive but locally-active characteristic. At an operating point in the locally-active region, a small-signal equivalent circuit is derived for describing the characteristics of the memristor near the operating point. By using the small-signal equivalent circuit, we show that the memristor possesses an edge of chaos in a voltage range, and that the memristor, when connected in series with an inductor,can oscillate about a locally-active operating point in the edge of chaos. And the oscillating frequency and the external inductance are determined by the small-signal admittance Y(iω). Furthermore, if the parasitic capacitor in parallel with the memristor is considered in the periodic oscillating circuit, the circuit generates chaotic oscillations.

关键词： memristor chaos local activity Hopf bifurcation

Radical Mechanism of IrⅢ/NiⅡ Metallaphotoredox-Catalyzed C(sp^(3))-H Functionalization Triggered by Proton-Coupled Electron Transfer:Theoretical Insight

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CCS Chemistry 2022年第4期4卷 1429-1440页

作者： yu-jiao dong Bo Zhu yun Geng Zhi-Wen Zhao Zhong-Min Su Wei Guan Institute of Functional Material Chemistry Faculty of ChemistryNortheast Normal UniversityChangchun 130024 College of Chemistry Jilin UniversityChangchun 130012

Photoredox catalysis can be induced to activate organic substrates or to modulate the oxidation state of transition-metal catalysts via unique singleelectron transfer processes,so as to achieve challenging C(sp^(3))-H functionalization under mild ***,the specific reaction mechanism and relevant electron transfer process still need to be ***,a highly regioselective Ir^(Ⅲ)/Ni^(Ⅱ)-metallaphotoredox-catalyzed hydroalkylation of asymmetrical internal alkyne with an etherα-hetero C(sp^(3))-H bond has been investigated by density functional theory(DFT)calculations.A novel radical mechanism was predicted to merge oxidative quenching(Ir^(Ⅲ)-*Ir^(Ⅲ)-Ir^(Ⅳ)-Ir^(Ⅲ))and nickel catalytic cycles(NiⅡ-NiⅢ-NiI-NiⅢ-NiⅡ)for this C(sp^(3))-H functionalization to construct C(sp^(3))-C(sp^(2))*** consists of seven major steps:the single-electron transfer involved in the photoredox cycle for generating active Ni(Ⅰ)-chloride complexes,proton-coupled electron transfer process to provide α-carbon-centered tetrahydrofuran(THF)radicals,radical capture by Ni(Ⅱ),reductive elimination to obtain 2-chlorotetrahydrofuran,alkyne oxidative hydrometallation,innersphere electron transfer,and σ-bond metathesis to yield the desired alkyne hydroalkylation ***,both the thermodynamic performance for redox potentials and the kinetic exploration for energy barriers and electron-transfer rates have also been evaluated for the corresponding electron transfer *** addition,the steric effects play a major role in determining the regioselectivity of alkyne oxidative hydrometallation.

关键词： C(sp^(3))-H functionalization photoredox catalysis iridium nickel density functional calculations

Predicting the evolution of electrochemical trepanning for inner blisks with a chamfer structure at blade tip

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Chinese Journal of Aeronautics 2024年第9期37卷 560-576页

作者： Erhao jiao dong ZHU Penghui WANG Hang ZUO Liyong CHEN College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China

Electrochemical trepanning(ECTr)is an effective electrochemical machining(ECM)technique that can be used to manufacture the integral components of aero-engine *** study focused on the dynamic evolution of ECTr for production of inner blisks(bladed disks)with a special chamfer structure at blade *** to the existence of chamfer,the ECTr process of inner blades is in a non-equilibrium state during the early stages,and the physical field changes in the machining gap are complex,making it difficult to predict the forming *** this paper,a dynamic evolution model(DEM)of inner blade ECTr with a special chamfer at blade tip structure is proposed,and an ECTr multi-physical fields simulation study was carried *** evolution of the chamfer at blade tip was analyzed and data related to chamfer were predicted based on the dependence of anode boundary properties with machining time and feed *** addition,the dis-tributions of current density,electrolyte flow rate,bubble volume fraction,temperature rise,and electrolyte conductivity in the machining area at different times were obtained by combining them with the multi-physical fields simulation ***,a series of ECTr experiments were conducted,in which,as the feed rate increased,the surface quality and machining accuracy of the inner blades were *** with the simulation results,the error in machining accu-racy of the chamfer profile is controlled within±2%,and the machining accuracy of the blade full profile was controlled within±0.2 mm,indicating that the model proposed in this study was effec-tive in predicting the evolution of inner blades ECTr with chamfer structures at blade tip.

关键词： Chamfer structure Inner blisk Electrochemical trepanning(ECTr) Dynamic evolution model Forming prediction Multiphysics Machining quality

Tuning oxygen redox via transition-metal cation species

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Science China Chemistry 2024年第7期67卷 2130-2131页

作者： Sichen jiao Xuelong Wang Xiqian yu Beijing Frontier Research Center on Clean Energy Institute of PhysicsChinese Academy of SciencesBeijing 100190China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

Lithium-rich layered oxides with a general formula of Li[Li_(x)Ni_(y)MnzCo_(1–x–y–z)]O_(2)(Li-rich NMCs,elements in bracket reside in the same layer)are recognized as promising candidates for the next generation hi... 详细信息

关键词： lithium oxides transition

New perspectives on the therapeutic potential of quercetin in non-communicable diseases:Targeting Nrf2 to counteract oxidative stress and inflammation

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Journal of Pharmaceutical Analysis 2024年第6期14卷 805-822页

作者： Li Zhang Li-yue Xu Fei Tang dong Liu Xiao-Lan Zhao Jing-Nan Zhang Jia Xia jiao-jiao Wu yu Yang Cheng Peng Hui Ao State Key Laboratory of Southwestern Chinese Medicine Resources School of PharmacyChengdu University of Traditional Chinese MedicineChengdu611137China Innovative Institute of Chinese Medicine and Pharmacy Chengdu University of Traditional Chinese MedicineChengdu611137China

Non-communicable diseases(NCDs),including cardiovascular diseases,cancer,metabolic diseases,and skeletal diseases,pose significant challenges to public health *** complex pathogenesis of these diseases is closely linked to oxidative stress and inflammatory *** factor erythroid 2-related factor 2(Nrf2),a critical transcription factor,plays an important role in regulating antioxidant and anti-inflammatory responses to protect the cells from oxidative damage and inflammation-mediated ***,Nrf2-targeting therapies hold promise for preventing and treating ***(Que)is a widely available flavonoid that has significant antioxidant and anti-inflammatory *** modulates the Nrf2 signaling pathway to ameliorate oxidative stress and *** modulates mitochondrial function,apoptosis,autophagy,and cell damage biomarkers to regulate oxidative stress and inflammation,highlighting its efficacy as a therapeutic agent against ***,we discussed,for the first time,the close association between NCD pathogenesis and the Nrf2 signaling pathway,involved in neurodegenerative diseases(NDDs),cardiovascular disease,cancers,organ damage,and bone ***,we reviewed the availability,pharmacokinetics,pharmaceutics,and therapeutic applications of Que in treating *** addition,we focused on the challenges and prospects for its clinical *** represents a promising candidate for the treatment of NCDs due to its Nrf2-targeting properties.

关键词： Quercetin Nrf2 Non-communicable diseases Antioxidant Anti-inflammatory Availability

Real-time model correction using Kalman filter for Raman-controlled cell culture processes

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Chinese Journal of Chemical Engineering 2024年第6期70卷 251-260页

作者： Xiaoxiao dong Zhuohong He Xu Yan dong Gao Jingyu jiao Yan Sun Haibin Wang Haibin Qu Pharmaceutical Informatics Institute College of Pharmaceutical SciencesZhejiang UniversityHangzhou 310058China Hisun Biopharmaceutical Co.Ltd. Hangzhou 311404China

Raman spectroscopy has found extensive use in monitoring and controlling cell culture *** this context,the prediction accuracy of Raman-based models is of paramount ***,models established with data from manually fed-batch cultures often exhibit poor performance in Raman-controlled ***,there is a need for effective methods to rectify these *** objective of this paper is to investigate the efficacy of Kalman filter(KF)algorithm in correcting Raman-based models during cell ***,partial least squares(PLS)models for different components were constructed using data from manually fed-batch cultures,and the predictive performance of these models was ***,various correction methods including the PLS-KF-KF method proposed in this study were employed to refine the PLS ***,a case study involving the auto-control of glucose concentration demonstrated the application of optimal model correction *** results indicated that the original PLS models exhibited differential performance between manually fed-batch cultures and Raman-controlled *** glucose,the root mean square error of prediction(RMSEP)of manually fed-batch culture and Raman-controlled culture was 0.23 and 0.40 g·L^(-1).With the implementation of model correction methods,there was a significant improvement in model performance within Raman-controlled *** RMSEP for glucose from updating-PLS,KF-PLS,and PLS-KF-KF was 0.38,0.36 and 0.17 g·L^(-1),***,the proposed PLS-KF-KF model correction method was found to be more effective and stable,playing a vital role in the automated nutrient feeding of cell cultures.

关键词： Raman spectroscopy Model correction Algorithm Model-predictive control Bioprocess

A N-CoSe/CoSe_(2)-C@Cu hierarchical architecture as a current collector-integrated anode for potassium-ion batteries

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Rare Metals 2024年第8期43卷 3702-3712页

作者： Zi-Jie Mu Yan-Jun Gao Wen-Shuai dong Zong-You Li Qing-Yi Song Han-jiao Huang Li-dong Xing Jian-Guo Zhang Wei Wang Qi-Yao yu State Key Laboratory of Explosion Science and Technology School of Mechatronical EngineeringBeijing Institute of TechnologyBeijing 100081China School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China

The highly reversible insertion/extraction of large-radius K^+into electrode materials remains a tough goal,especially for con version-type ***,we design a current collector-integrated electrode(N-CoSe/CoSe_(2)-C@Cu) as an advanced anode for potassium-ion battery(PIBs).The conductive CoSe/CoSe_(2) heterojunction with rich Se vacancy defects,conductive sp^2 N-doped carbon layer,and the elastic copper foil matrix can greatly accelerate the electron transfer and enhance the structural ***,the well-designed N-CoSe/CoSe_(2)-C@Cu current collector-integrated electrode displays enhanced potassium storage performance with regard to a high capacity(325.1 mAh·g^(-1) at 0.1 A·g^(-1) after 200cycles),an exceptional rate capability(223.5 mAh·g^(-1) at2000 mA·g^(-1)),and an extraordinary long-term cycle stability(a capacity fading of only 0.019% per cycle over1200 cycles at 2000 mA·g^(-1)).Impressively,ex situ scanning electron microscopy(SEM) characterizations prove that the elastic structure of copper foil is merged into the cleverly designed N-CoSe/CoSe_(2)-C@Cu heterostructure,which buffers the deformation of structure and volume and greatly promotes the cycle life during the potassium/depotassium process.

关键词： Potassium-ion battery Integrated collector electrode CoSe CoSe_2 Heterojunction Copper foil matrix N-doped carbon

Investigation on the vortical structures by the Liutex method in turbulent channels at Re_(τ)=180 with scalloped and triangular riblet control

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Journal of Hydrodynamics 2024年第1期36卷 35-52页

作者： Zhang-dan yu Shang Jiang Hai-dong yu Bi-yu Pang Xin dong Yi-qian Wang School of Mathematical Sciences Soochow UniversitySuzhou215006China Beijing Institute of Astronautical System Engineering Beijing100076China

Riblets are a series of small protrusions formed along the flow direction,which have been extensively studied as a passive turbulent drag reduction *** and numerical simulations have shown that well-designed riblets can significantly reduce drag in turbulent flows,making them highly promising and valuable for various *** this study,we focus on a scalloped riblet,which is designed by smoothly connecting two third-order polynomials,and thus the sharpness of the tip and the curvature of the valley can be well *** conduct direct numerical simulations of turbulent channel with smooth plate,scalloped riblet-mounted and triangular riblet-mounted *** in wall units of W^(+)=20 and height-width ratio ofγ=0.5 are selected for both riblet *** with the smooth plate case,the scalloped riblet case achieves an 8.68%drag reduction,while the triangular riblet case achieves a 4.79%drag *** obtained drag reduction rate of the triangular riblet is consistent with previous experiments and simulations,and the results indicate that the scalloped riblet is more effective in reducing drag and deserves further *** compare turbulent statistics of the scalloped riblet case with those of the triangular riblet *** mean velocity profiles of riblets are similar,but both the Reynolds shear stress and second-order statistics of velocity fluctuations and Liutex are significantly reduced in the scalloped riblets controlled turbulent channel,indicating that the scalloped riblet can more effectively suppress the spanwise and wall-normal turbulent intensity near the *** also compare the pre-multiplied spectra of streamwise velocity and streamwise Liutex component for the three cases to investigate the energy distribution and characteristics of Liutex *** Liutex vortex identification method is also utilized to analyze the instantaneous flow field,which provides insights into the flow field and could be bene

关键词： Liutex vector riblet drag reduction tip sharpness turbulent channel scalloped

Analysis and experimental study on resistance-increasing behavior of composite high efficiency autonomous inflow control device

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Petroleum Science 2024年第2期21卷 1290-1304页

作者： Liang-Liang dong yu-Lin Zhang School of Mechatronic Engineering Southwest Petroleum UniversityChengdu610500SichuanChina State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu610500SichuanChina Oil and Gas Equipment Technology Sharing and Service Platform of Sichuan ProvinceChengdu610500SichuanChina

Bottom water coning is the main reason to reduce the recovery of horizontal bottom water reservoir. By water coning, we mean the oil-water interface changes from a horizontal state to a mound-shaped cone and breaks through to the wellbore. Autonomous inflow control device(AICD) is an important instrument maintain normal production after bottom water coning, however, the resistance increasing ability of the swirl type AICD is insufficient at present, which seriously affects the water control effect. Aiming this problem, this paper designs a multi-stage resistance-increasing and composite type AICD. The separation mechanism of oil-water two phases in this structure, the resistance form of oil-water single phase and the resistance-increasing principle of water phase are analyzed. Establishing the dual-phase multi-stage separation and resistance-increasing model, and verified by measuring the throttling pressure drop and oil-water volume fraction of the AICD, it is found that the composite type AICD has the effect of ICD and AICD at the same time, which can balance the production rate of each well section at the initial stage of production, delay the occurrence of bottom water coning. In the middle and later stages of production, water-blocking can be effectively increased to achieve water control and stable *** structural sensitivity analysis, the influence law of various structural parameters on the water control performance of composite AICD was obtained. The simulation calculation results show that,compared with the existing swirl type AICD, composite AICD has higher sensitivity to moisture content,the water phase throttling pressure drop is increased by 4.5 times on average. The composite AICD is suitable for the entire stage of horizontal well production.

关键词： Water control Flow separation Flow resistance-increasing AICD device Simulation and experiment