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Renewable synthetic fuel:turning carbon dioxide back into fuel

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Frontiers in Energy 2022年第2期16卷 145-149页

作者： zhen HUANG lei ZHU Ang LI Zhan GAO Key Laboratory for Power Machinery and Engineering of the Ministry of Education Shanghai Jiao Tong UniversityShanghai 200240China China Research Institute of Carbon Neutrality Shanghai Jiao Tong UniversityShanghai 200240China

Climate change has emerged as one of the major challenges *** the First Industrial Revolution,the discovery and utilization of fossil energy has promoted the great prosperity and development of human ***,serious issues of environmental and climate change have *** May 2021,CO_(2) concentration in the atmosphere reached 419.13 ppm,observed by the National Oceanic and Atmospheric Administration(NOAA)of US,which arrives at the highest value in human history[1].The CO_(2)-based greenhouse gas emissions lead to global warming,which causes a serious threat to the survival of human being as well as sustainable development of *** September 2020,it was announced that China would scale up its nationally determined contributions and adopt more vigorous policies and activities to peak carbon dioxide emissions before 2030 and achieve carbon neutrality before 2060.

关键词： turning dioxide carbon

A Large Range Flexure-Based Servo System Supporting Precision Additive Manufacturing

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Engineering 2017年第5期3卷 708-715页

作者： zhen Zhang peng Yan Guangbo Hao State Key Laboratory of Tribology & Institute of Manufacturing Engineering Tsinghua University Beijing 100084 China Beijing Key Laboratory of Precision/Ultra-Precision Manufacturing Equipment and Control Tsinghua University Beijing 100084 China Department of Mechanical Engineering Tsinghua University Beijing 100084 China Key Laboratory of High-Efficiency and Clean Mechanical Manufacturing Ministry of Education School of Mechanical Engineering Shandong UniversityJinan 250061 China Department of Electrical and Electronic Engineering University College Cork Cork Ireland

This paper presents the design, development, and control of a large range beam flexure-based nano servo system for the micro-stereolithography （MSL） process. As a key enabler of high accuracy in this process, a compact desktop-size beam flexure-based nanopositioner was designed with millimeter range and nanometric motion quality. This beam flexure-based motion system is highly suitable for harsh operation conditions, as no assembly or maintenance is required during the operation. From a mechanism design viewpoint, a mirror-symmetric arrangement and appropriate redundant constraints are crucial to reduce undesired parasitic motion. Detailed finite element analysis （FEA） was conducted and showed satisfactory mechanical features. With the identified dynamic models of the nanopositioner, real-time control strategies were designed and implemented into the monolithically fabricated prototype system, demonstrating the enhanced tracking capability of the MSL process. The servo system has both a millimeter operating range and a root mean square （RMS） tracking error of about 80 nm for a circular traiectorv.

关键词： Precision additive manufacturing Micro-stereolithography Nanopositioning Beam flexure

Accurate atomic scanning transmission electron microscopy analysis enabled by deep learning

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Nano Research 2024年第4期17卷 2971-2980页

作者： Tianshu Chu lei Zhou Bowei Zhang Fu-zhen Xuan Shanghai Key Laboratory of Intelligent Sensing and Detection Technology East China University of Science and TechnologyShanghai 200237China School of Mechanical and Power Engineering East China University of Science and TechnologyShanghai 200237China Key Laboratory of Pressure Systems and Safety of Ministry of Education East China University of Science and TechnologyShanghai 200237China

Currently,the machine learning(ML)-based scanning transmission electron microscopy(STEM)analysis is limited in the simulative stage,its application in experimental STEM is needed but ***,we built up a universal model to analyze the vacancy defects and single atoms accurately and rapidly in experimental STEM images using a full convolution *** our model,the unavoidable interference factors of noise,aberration,and carbon contamination were fully considered during the training,which were difficult to be considered in the *** toward the simultaneous identification of various vacancy types and low-contrast single atoms in the low-quality STEM images,our model showed rapid process speed(45 images per second)and high accuracy(>95%).This work represents an improvement in experimental STEM image analysis by ML.

关键词： deep learning low-dimensional materials atomic defects single atoms

Sampled-data extended state observer for uncertain nonlinear systems

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Control Theory and Technology 2016年第3期14卷 189-198页

作者： Chuan TIAN peng YAN zhen ZHANG School of Automation Science and Electrical Engineering Beihang University Beijing 100191 China Key Laboratory of High-efficiency and Clean Mechanical Manufacturing Ministry of Education School of Mechanical Engineering Shandong University Jinan Shandong 250061 China Department of Mechanical Engineering Tsinghua University Beijing 100084 China

In this paper, we present a sampled-data nonlinear extended state observer （NLESO） design method for a class of nonlinear systems with uncertainties and discrete time output measurement. To accommodate the inter-sample dynamics, an inter-sample output predictor is employed in the structure of the NLESO to estimate the system output in the sampling intervals, where the prediction is used in the proposed observer instead of the system output. The exponential convergence of the sampled-data NLESO is also discussed and a sufficient condition is given by the Lyapunov method. A numerical example is provided to illustrate the performance of the proposed observer.

关键词： Sampled-data extended state observer nonlinear systems

Removal Mechanism of Aqueous Lead by a Novel Eco-material: Carbonate Hydroxyapatite

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Journal of Materials Science & Technology 2007年第3期23卷 417-422页

作者： Huanyan XU lei YANG peng WANG Yu LIU Mingsheng peng School of Materials Science and Engineering Harbin University of Science and Technology Harbin 150040 China School of Municipal and Environmental Engineering Harbin Institute of Technology Harbin 150090 China School of Materials Science and Engineering Wuhan Institute of Technology Wuhan 430073 China Department of Earth Sciences Zhongshan University Guangzhou 510275 China

Kinetics and mechanisms on the removal of aqueous lead ion by carbonate hydroxyapatite （CHap） are investigated in the present work. Experimental results show that, in the whole pH range, the lead removal percentage increases with decreasing pH values and reaches a maximum at pH=2-3. Under some conditions, the lead residual concentration is below national integrated wastewater discharge standard, even drinking water standard. The removal behavior is a complicated non-homogeneous solid/liquid reaction, which can be described by two stages from kinetic point of view. At the earlier stage, reaction rate is so fast that its kinetic course is intricate, which requires further study. At the latter stage, the rate of reaction becomes slow and the process of reaction accords with one order reaction kinetic equation. Experimental results show that the relationship between reaction rate constant k1 and temperature T accords to Arrhenius Equation, and the activation energy of sorption （Ea） is 11.93 kJ/mol and frequency factor （A） is 2.51 s^-1. X-ray diffraction （XRD）, scanning electron microscopy with an energy dispersive X-ray fluoresence spectrometer （SEM-EDS） and toxicity characteristic leaching procedure （TCLP） test were conducted in this work. It is indicated that the main mechanism is dissolution-precipitation, accompanying with superficial sorption.

关键词： Carbonate hydroxyapatite Lead ion Mechanism Dissolution-precipitation

Plasma Replacement Therapy for Alzheimer's Disease

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Neuroscience Bulletin 2020年第1期36卷 89-90页

作者： Xu-long Ding peng lei Department of Neurology and State Key Laboratory of Biotherapy West China HospitalSichuan UniversityChengdu 610041China West China School of Basic Medical Sciences and Forensic Medicine Sichuan UniversityChengdu 610041China Collaborative Innovation Center for Biotherapy Chengdu 610041China

Alzheimer’s disease(AD)is the most common neurode-generative disease that affects memory,thinking,behavior,and the ability to perform everyday *** has been estimated that more than 35 million people worldwide suffered from AD in 2018[1],and this figure continues to ***,no cure or treatment that slows the progression of the disease has been discovered despite extensive efforts from academics and the pharmaceutical *** drug trials for AD have targeted the 13-amyloid protein[2],which accumulates in this disease,and the failure of amyloid-based drugs to impact on cognition in people with AD has led to re-questioning of the amyloid hypothesis of AD,and has provided a fresh impetus to explore alternative therapeutic strategies.

关键词： Alzheimer drugs everyday

Data-driven rational design of single-atom materials for hydrogen evolution and sensing

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Nano Research 2024年第4期17卷 3352-3358页

作者： lei Zhou pengfei Tian Bowei Zhang Fu-zhen Xuan Shanghai Key Laboratory of Intelligent Sensing and Detection Technology East China University of Science and TechnologyShanghai 200237China School of Mechanical and Power Engineering East China University of Science and TechnologyShanghai 200237China Key Laboratory of Pressure Systems and Safety of Ministry of Education East China University of Science and TechnologyShanghai 200237China

Herein we proposed a data-driven high-throughput principle to screen high-performance single-atom materials for hydrogen evolution reaction(HER)and hydrogen sensing by combing the theoretical computations and a topology-based multi-scale convolution kernel machine learning *** the rational training by 25 groups of data and prediction of all 168 groups of single-atom materials for HER and sensing,respectively,a high prediction accuracy(>0.931 R^(2) score)was achieved by our *** show that the promising HER catalysts include Pt atoms in C_(4) and Sc atoms in C_(1)N_(3) coordination ***,Y atoms in C_(4) coordination environment and Cd atoms in C_(2)N_(2)-ortho coordination environment were predicted with great potential as hydrogen sensing *** method provides a way to accelerate the discovery of innovative materials by avoiding the time-consuming empirical principles in experiments.

关键词： machine learning single-atom materials sensing hydrogen evolution

Scheme for Generation of Maximally Entangled States via Entanglement Swapping

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Communications in Theoretical Physics 2006年第3X期46卷 553-555页

作者： WU zhen-zhen FANG Mao-Fa JIANG Chun-lei College of Physics and Information Science Hunan Normal University Changsha 410081 China

Based on two atoms and two cavities initially in two pairs of atom-photon nonmaximally entangled states, we propose a relatively simple scheme to create maximally entangled photon-photon and atom-photon states via entanglement swapping using techniques of cavity QED inspired by the scheme proposed in [Phys. Rev. A 71 （2005） 044302] and [Phys. Rev. A 71 （2005） 034312]. Our scheme does not involve the measurement in Bell basis, we only require detecting the states of atoms.

关键词： quantum entanglement entanglement swapping cavity QED

Experimental study of the effects of a multistage pore-throat structure on the seepage characteristics of sandstones in the Beibuwan Basin:Insights into the flooding mode

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Petroleum Science 2024年第2期21卷 1044-1061页

作者： lei Wang Xiao lei Qiao-Liang Zhang Guang-Qing Yao Bo Sui Xiao-Jun Chen Ming-Wei Wang zhen-Yu Zhou Pan-Rong Wang Xiao-Dong peng Zhanjiang Branch China National Offshore Oil Corporation(CNOOC)LimitedZhanjiang524057GuangdongChina Faculty of Earth Resources China University of Geosciences(Wuhan)Wuhan430074HubeiChina School of Resources and Safety Engineering Chongqing UniversityChongqing400044China School of Engineering University of ManchesterManchester M139WJUK Hainan Branch China National Offshore Oil Corporation(CNOOC)LimitedHaikou570311HainanChina

To investigate the relationship between grain sizes, seepage capacity, and oil-displacement efficiency in the Liushagang Formation of the Beibuwan Basin, this study identifies the multistage pore-throat structure as a crucial factor through a comparison of oil displacement in microscopic pore-throat experiments. The two-phase flow evaluation method based on the Li-Horne model is utilized to effectively characterize and quantify the seepage characteristics of different reservoirs, closely relating them to the distribution of microscopic pores and throats. It is observed that conglomerate sandstones at different stages exhibit significant heterogeneity and noticeable differences in seepage capacity, highlighting the crucial role played by certain large pore throats in determining seepage capacity and oil displacement efficiency. Furthermore, it was found that the displacement effects of conglomeratic sandstones with strong heterogeneity were inferior to those of conventional homogeneous sandstone, as evidenced by multiple displacement experiments conducted on core samples with varying granularities and flooding systems. Subsequently, core-based experiments on associated gas flooding after water flooding were conducted to address the challenge of achieving satisfactory results in a single displacement mode for reservoirs with significant heterogeneity. The results indicate that the oil recovery rates for associated gas flooding after water flooding increased by 7.3%-16.4% compared with water flooding alone at a gas-oil ratio of approximately 7000 m^(3)/m^(3). Therefore, considering the advantages of gas flooding in terms of seepage capacity, oil exchange ratio, and the potential for two-phase production, gas flooding is recommended as an energy supplement mode for homogeneous reservoirs in the presence of sufficient gas source and appropriate tectonic angle. On the other hand, associated gas flooding after water flooding is suggested to achieve a more favorable develop

关键词： Beibuwan Basin Multistage pore-throat structure Multistage seepage characteristics Microscopic visualization Heterogeneity Gas/water flooding Flooding mode