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Influence of rare-earth metal doping on the catalytic performance of CuO-CeO_2 for the preferential oxidation of CO in excess hydrogen

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Journal of Natural Gas Chemistry 2008年第3期17卷 283-287页

作者： zhigang liu renxian zhou xiaoming zheng Institute of Catalysis Zhejiang University Hangzhou 310028 Zhejiang China School of Chemistry and Chemical Engineering Hunan University Changsha 410082 Hunan China

Doping of different rare-earth metals （Pr, Nd, Y and La） had an evident influence on the catalytic performance of CuO-CeO2 for the preferential oxidation （PROX） of CO in excess hydrogen. As for Pr, the doping enhanced the catalytic activity of CuO-CeO2 for PROX. For example, the CO conversion over the above catalyst for PROX was higher than 99% at 120 °C. Especially, the doping of Pr widened the temperature window by 20 °C over CuO-CeO2 with 99% CO conversion. For Nd, Y, and La, the doping depressed the catalytic activity of CuO-CeO2 for PROX. However, the doping of transition metals markedly improved the selectivity of CuO-CeO2 for PROX.

关键词： CuO-CeO2 rare-earth metal doping CO

Three-dimensional fracture of UO2 ceramic pellets by phase field modeling

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 169-180页

作者： Wei Xiong Xuan Ye Hongzhang Cheng xiaoming liu Institute of Nuclear and New Energy Technology Collaborative Innovation Center of Advanced Nuclear Energy Technology Key Laboratory of Advanced Reactor Engineering and Safety of Ministry of Education Tsinghua University State Key Laboratory of Nonlinear Mechanics Institute of Mechanics Chinese Academy of Sciences School of Engineering Science University of Chinese Academy of Sciences

Fracture is the primary failure type for the UO2ceramic pellets,which are operated under irradiation and thermal processes,and physically confined by the *** this work,by combining closely coupled physical processes of heat conduction,heat transfer,and mechanical deformation with the cohesive phase field framework,we proposed a high-precision modeling of quasistatic cracking of three-dimensional （3D） UO2ceramic fuel pellets under high temperature and *** simulation results agree well with the experimental results,indicating that the proposed method has the potential to capture 3D crack modes in the interested time ***,we studied the relation of the 3D fracture patterns of fuel pellets with the peak power *** was found that the power level plays a critical role in determining the competition between radial and circumferential cracks,as well as transverse penetrating cracks.

关键词： phase field method nuclear fuel pellet coupled thermo-mechanical model thermal fracture

Influence of preparation methods on CuO-CeO_2 catalysts in the preferential oxidation of CO in excess hydrogen

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Journal of Natural Gas Chemistry 2008年第2期17卷 125-129页

作者： zhigang liu renxian zhou xiaoming zheng School of Chemistry and Chemical Engineering Hunan University Changsha 410082 China Institute of Catalysis. Zhejiang University Hangzhou 310028 China

Influence of three different preparation methods, i.e. impregnation, coprecipitation, and inverse coprecipitation, on the preferential oxidation of CO in excess hydrogen （PROX） over CuO-CeO2 catalysts has been investigated and CuO-CeO2 catalysts are characterized using BET, XPS, XRD, UV Raman, and TPR techniques. The results show that the catalysts prepared by coprecipitation have smaller particle sizes, well-dispersed CuOx species, more oxygen vacancies, and are more active in the PROX than those prepared by the other methods. However. the inverse coprecipitation depresses the catalytic performance of CuO-CeO2 catalysts and causes the growth of CuO-CeO2 because of different pH value in the precipitation process.

关键词： CuO-CeO2 preparation method preferential oxidation CO fuel cell

Multi boron-doping effects in hard carbon toward enhanced sodium ion storage

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Journal of Energy Chemistry 2025年第1期100卷 730-738页

作者： Peng zheng Wang zhou Ying Mo Biao zheng Miaomiao Han Qin Zhong Wenwen Yang Peng Gao Lezhi Yang Jilei liu College of Materials Science and Engineering Hunan Joint International Laboratory of Advanced Materials and Technology for Clean Energy Hunan Province Key Laboratory for Advanced Carbon Materials and Applied Technology Hunan University Greater Bay Area Institute for Innovation Hunan University Changsha Research Institute of Mining & Metallurgy Co. LTD.

Hard carbon （HC） has been considered as promising anode material for sodium-ion batteries （SIBs）.The optimization of hard carbon’s microstructure and solid electrolyte interface （SEI） property are demonstrated effective in enhancing the Na+storage capability,however,a one-step regulation strategy to achieve simultaneous multi-scale structures optimization is highly ***,we have systematically investigated the effects of boron doping on hard carbon’s microstructure and interface chemistry.A variety of structure characterizations show that appropriate amount of boron doping can increase the size of closed pores via rearrangement of carbon layers with improved graphitization degree,which provides more Na+storage ***-situ Fourier transform infrared spectroscopy/electrochemical impedance spectroscopy （FTIR/EIS） and X-ray photoelectron spectroscopy （XPS） analysis demonstrate the presence of more BC3and less B–C–O structures that result in enhanced ion diffusion kinetics and the formation of inorganic rich and robust SEI,which leads to facilitated charge transfer and excellent rate *** a result,the hard carbon anode with optimized boron doping content exhibits enhanced rate and cycling *** general,this work unravels the critical role of boron doping in optimizing the pore structure,interface chemistry and diffusion kinetics of hard carbon,which enables rational design of sodium-ion battery anode with enhanced Na+storage performance.

关键词： X ray photoelectron spectroscopy

Influence of pH values in the preparation of CuO-CeO_2 on its catalytic performance for the preferential oxidation of CO in excess hydrogen

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Journal of Natural Gas Chemistry 2010年第3期19卷 313-317页

作者： zhigang liu Shuren Yang renxian zhou xiaoming zheng School of Chemistry and Chemical Engineering Hunan University Changsha 410082 Hunan China Institute of Catalysis Zhejiang University Hangzhou 310028 Zhejiang China

CuO-CeO2 catalyst prepared with co-precipitation showed high catalytic performance for the preferential oxidation of CO in excess hydrogen（PROX）.Influence of pH values in the preparation of CuO-CeO2 on its catalytic performance was investigated in this *** CuO-CeO2 catalyst prepared at pH = 13.03 had the smallest particle size（5.4 nm）,the largest surface areas（138m 2/g） and the highest activity with CO conversion of 99.6% at 130 ℃.The CuO-CeO2 catalyst was characterized using BET,XRD and TPR *** results showed that when the pH value of the mixed solution containing Cu and Ce species was properly adjusted,both the adsorption layers and diffusion layers of the formed colloidal particles in hydroxide precursor of CuO-CeO2 were modified,resulting in the better catalytic performance for PROX on the final CuO-CeO2 catalyst

关键词： CuO-CeO pH mechanism CO preferential oxidation

Influence of reduction energy match among CuO species in CuO-CeO_2 catalysts on the catalytic performance for CO preferential oxidation in excess hydrogen

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Journal of Natural Gas Chemistry 2011年第2期20卷 111-116页

作者： zhigang liu Yunlong Xie Wensheng Li renxian zhou xiaoming zheng School of Chemistry and Chemical Engineering Hunan University Changsha 410082 Hunan China Institute of Catalysis Zhejiang University Hangzhou 310028 Zhejiang China Institute of Physical Chemical Zhejiang Normal University Jinhua 321004 Zhejiang China

In the present study, we have investigated the reducibility of CuO species on CuO-CeO2 catalysts and the influence of CuO species on the catalytic performance for CO preferential oxidation （CO PROX） in excess hydrogen. It is revealed that the smaller the difference of reduction temperature （denoted as ？T） for two adjacent CuO species is, the higher the catalytic activity of CuO-CeO2 for the PROX in excess hydrogen may be obtained. It means that if the reduction energy of Cu0-Cu2＋ pairs matched better, the reduction-oxidation recycle of Cu0-Cu2＋ pairs would go on more easily, then the transferring energy of Cu0-Cu2＋ pairs would be lesser. Therefore, the CuO-CeO2 catalysts will be largely improved in their catalytic performance if the different CuO species on the catalysts have matched the reduction energy, which would allows them to cooperate effectively.

关键词： energy match cooperative effect CuO-CeO2 preferential oxidation CO

The role of axon guidance molecules in the pathogenesis of epilepsy

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Neural Regeneration Research 2025年第5期20卷 1244-1257页

作者： zheng liu Chunhua Pan Hao Huang Department of Neurology Affiliated Hospital of Zunyi Medical UniversityZunyiGuizhou ProvinceChina

Current treatments for epilepsy can only manage the symptoms of the condition but cannot alter the initial onset or halt the progression of the disease. Consequently, it is crucial to identify drugs that can target novel cellular and molecular mechanisms and mechanisms of action. Increasing evidence suggests that axon guidance molecules play a role in the structural and functional modifications of neural networks and that the dysregulation of these molecules is associated with epilepsy susceptibility. In this review, we discuss the essential role of axon guidance molecules in neuronal activity in patients with epilepsy as well as the impact of these molecules on synaptic plasticity and brain tissue remodeling. Furthermore, we examine the relationship between axon guidance molecules and neuroinflammation, as well as the structural changes in specific brain regions that contribute to the development of epilepsy. Ample evidence indicates that axon guidance molecules, including semaphorins and ephrins, play a fundamental role in guiding axon growth and the establishment of synaptic connections. Deviations in their expression or function can disrupt neuronal connections, ultimately leading to epileptic seizures. The remodeling of neural networks is a significant characteristic of epilepsy, with axon guidance molecules playing a role in the dynamic reorganization of neural circuits. This, in turn, affects synapse formation and elimination. Dysregulation of these molecules can upset the delicate balance between excitation and inhibition within a neural network, thereby increasing the risk of overexcitation and the development of epilepsy. Inflammatory signals can regulate the expression and function of axon guidance molecules, thus influencing axonal growth, axon orientation, and synaptic plasticity. The dysregulation of neuroinflammation can intensify neuronal dysfunction and contribute to the occurrence of epilepsy. This review delves into the mechanisms associated with

关键词： axon guidance drug-resistant epilepsy epilepsy nerve regeneration nervous system diseases neural pathways neuroinflammatory diseases neuronal plasticity neurons synaptic remodeling

Mitigating methodology of hardware non-ideal characteristics for non-volatile memory based neural networks

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Science China(Information Sciences) 2025年

作者： Lixia HAN Peng HUANG Yijiao WANG zheng zhou Haozhang YANG Yiyang CHEN Xiaoyan liu Jinfeng KANG School of Integrated Circuits Peking University Beijing Advanced Innovation Center for Integrated Circuits School of Integrated Circuit Science and Engineering Beihang University

Non-volatile memory-based computing-in-memory (nvCIM) paradigm has been extensively studied to boost the energy efficiency of neural network accelerators in edge ***,the degradation of inference accuracy induced by the non-ideal characteristics across circuits,arrays,and devices is becoming a crucial *** this work,we establish a hardware characteristic behavior model to analyze the impact of nvCIM non-ideal characteristics on neural network *** we propose a hardware aware training and weight mapping correction methods to mitigate inference accuracy *** simulation verification,about 95%inference accuracy degradation is recovered by adopting the proposed mitigation method for various non-ideal characteristics and various neural network *** feasibility of the proposed method is further proved in an experimental example with a flash-based LeNet recognition system.

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Near-perfect replication on amorphous alloys through active force modulation based on machine learning/neural network parameter prediction

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 181-191页

作者： Senkuan Meng zheng Wang Ruisong Zhu Ruijie liu Jiang Ma Lina Hu Weihua Wang Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education) School of Materials Science and Engineering Shandong University College of Mechatronics and Control Engineering Shenzhen University Songshan Lake Materials Laboratory Institute of Physics Chinese Academy of Sciences

As a microforming technique, micro/nano-structural replication possesses advantages of high precision and efficiency. With the remarkable superplasticity in the supercooled liquid region, amorphous alloys or metallic glasses(MGs) are regarded as ideal materials for miniature fabrication. However, due to the intrinsic metastable nature of supercooled liquids, the design of imprinting processes for MGs poses a challenge. In the past, process parameters have largely relied on trial-and-error *** this work, a low-frequency active force modulation system is employed to apply a stable, precise, and real-time feedback stress field for imprinting of MG samples. Low-frequency vibrations can facilitate the filling of microstructures on the template surface by reducing the effective viscosity of the supercooled liquid. With the dataset composed of orthogonal experiments, a machine learning strategy based on back-propagation(BP) neural networks was utilized to construct a 3D parameter space for temperature, stress, and time, and to predict the corresponding filling ratio. Furthermore, the optimal combination of imprinting process parameters was identified, and its filling ratio was experimentally validated to reach as high as 0.94. The near-perfect replication of microstructures confirms the superiority of the active force modulation system and the data-driven strategy of machine learning-assisted parameter design. At the same time, this one-step microforming process provides a new approach to addressing the accuracy-cost trade-off dilemma in precision manufacturing.

关键词： metallic glass amorphous alloy microforming imprinting machine learning