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Science China Chemistry 2025年

作者： Lulu Chen Yichao Huang jiajun wang Meihong Liao Zhiyuan Liu Meiqi Liu Hanqing Cai Lin wang Lidong Gao Dawei Hu Lianming Zhao Ning Pu Zhuangjun Fan State Key Laboratory of Chemical Safety School of Materials Science and Engineering China University of Petroleum (East China) School of Mechanical and Electronic Engineering Qingdao Binhai University Qingdao Chuangqi New Energy Catalysis Technology Co.Ltd. Sinopec Research Institute of Petroleum Processing Co.Ltd. Institute of Energy Hefei Comprehensive National Science Center

Insight into the growth behavior and electronic regulation of platinum （Pt） on various transition metal supports is paramount in developing high-performing electrocatalysts for hydrogen evolution reactions （HER）.Herein,we studied the influence of molybdenum-based supports （MoX,X=C,N,P,and S） on the growth behavior and electronic regulation of *** found that the formation energy variations between Pt single atom and clusters on MoX supports play a pivotal role in the growth behavior of ***,the electronic regulation of Pt induced by metal-support interaction may reflect the valence changes of Pt in Pt-MoX/*** Pt-MoC/C catalyst with a moderate valence state of Pt exhibits the best HER activity with an overpotential of 12.0 mV at 10 mA cm-2and a mass activity of 27.1 A mgPt-1,12.3 times as high as that of commercial 20 wt% Pt/*** work provides constructive guidance for the design of high-performance HER catalysts.

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Speed-assigned Position Tracking Control of SRM With Adaptive Backstepping Control

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IEEE/CAA Journal of Automatica Sinica 2018年第6期5卷 1128-1135页

作者： jiajun wang School of Automation Hangzhou Dianzi University

A novel speed-assigned method is applied to the position tracking control of switched reluctance motor(SRM).A speed control freedom can be drawn into the position control through speed assignment. Adaptive backstepping control is used to design the position controller for the SRM. The accuracy of position tracking of the SRM can be enhanced with speed assignment. A disturbance observer is further designed to enhance the estimation accuracy of the unknown load torque. Simulation results certify that the design scheme is right and effective.

关键词： Backstepping control direct torque control (DTC) disturbance observer speed-assigned position tracking control switched reluctance motor (SRM)

Parameter Optimization of Interval Type-2 Fuzzy Neural Networks Based on PSO and BBBC Methods

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IEEE/CAA Journal of Automatica Sinica 2019年第1期6卷 247-257页

作者： jiajun wang Tufan Kumbasar the School of Automation Hangzhou Dianzi University IEEE the Control and Automation Engineering Department Faculty of Electrical and Electronics EngineeringIstanbul Technical University

Interval type-2 fuzzy neural networks(IT2FNNs)can be seen as the hybridization of interval type-2 fuzzy systems(IT2FSs) and neural networks(NNs). Thus, they naturally inherit the merits of both IT2 FSs and NNs. Although IT2 FNNs have more advantages in processing uncertain, incomplete, or imprecise information compared to their type-1 counterparts, a large number of parameters need to be tuned in the IT2 FNNs,which increases the difficulties of their design. In this paper,big bang-big crunch(BBBC) optimization and particle swarm optimization(PSO) are applied in the parameter optimization for Takagi-Sugeno-Kang(TSK) type IT2 FNNs. The employment of the BBBC and PSO strategies can eliminate the need of backpropagation computation. The computing problem is converted to a simple feed-forward IT2 FNNs learning. The adoption of the BBBC or the PSO will not only simplify the design of the IT2 FNNs, but will also increase identification accuracy when compared with present methods. The proposed optimization based strategies are tested with three types of interval type-2 fuzzy membership functions(IT2FMFs) and deployed on three typical identification models. Simulation results certify the effectiveness of the proposed parameter optimization methods for the IT2 FNNs.

关键词： Big bang-big crunch (BBBC) interval type-2 fuzzy neural networks (IT2FNNs) parameter optimization particle swarm optimization (PSO)

A novel CRISPR/Cas9 system for efficiently generating Cas9- free multiplex mutants in Arabidopsis

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aBIOTECH 2020年第1期1卷 6-14页

作者： jiajun wang Haodong Chen State Key Laboratory of Protein and Plant Gene Research School of Advanced Agricultural Sciences and School of Life SciencesPeking-Tsinghua Center for Life SciencesPeking UniversityBeijing 100871China

The CRISPR/Cas9 genome-editing system has emerged as a popular powerful tool for biological ***,the process of selecting efficiently edited Cas9-free plants is usually laborious and time ***,we demonstrated P2A to be the most efficient self-cleaving peptide for fusing Cas9 and GFP in Arabidopsis and then used Cas9-P2A-GFP to develop a novel CRISPR/Cas9 ***,a pair of isocaudomer restriction enzymes were selected to conveniently assemble multiple *** this system,the GFP fluorescence intensity in T1 transgenic plants indicates the expression level of the Cas9 protein,which correlates well with the editing ***,Cas9-free plants can be easily selected by examining GFP fluorescence in T2 transgenic *** efficient knockout of BRI1,BZR1 and BES1 demonstrated the robustness of our new ***,we designed a novel CRISPR/Cas9 system that can generate Cas9-free multiplex mutants efficiently in Arabidopsis and possibly in other plant species.

关键词： CRISPR Cas9 Cas9-free P2A Multiplex mutant Arabidopsis

Three Dimensional Morphology and Microstructural Evolution of Bainite in Steels

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Journal of Materials Science & Technology 1998年第6期14卷 559-563页

作者： Bo, Xiangzheng Fang, Hongsheng wang, jiajun Tsing Hua Univ Dept Mat Sci & Engn Beijing 100084 Peoples R China

The 3-D morphology of bainite in steels has been studied by SEM with high resolution. Based on the dual-surface observation results, the bainite is divided into three sub-categories: upper, transient and lower bainites. The subplates composing upper bainite sheaf are lath-like while the whole morphology of lower bainite and that of its subplates are plate-shaped. The subunits in lower bainite seem to be lumpish. The 3-D morphology of transient bainite proves to resemble both upper and lower bainites on some aspects. The microstructural evolution of three types of bainite has been discussed. (Edited author abstract) 4 Refs.

关键词： Steel

Multi-Scale X-Ray Imaging Technologies for Rechargeable Batteries

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Chinese Physics Letters 2024年第8期41卷 107-120页

作者： Zihan Xu Hanwen An jiajun wang MOE Engineering Research Center for Electrochemical Energy Storage and Carbon Neutrality in Cold Regions School of Chemistry and Chemical EngineeringHarbin Institute of Technology Harbin 150001China State Key Laboratory of Space Power Sources Harbin Institute of TechnologyHarbin 150001China Chongqing Research Institute of HIT Chongqing 401135China

The rapid advancement in electric vehicles and electrochemical energy storage technology has raised the demands placed on rechargeable *** is essential to comprehend the operational principles and degradation mechanisms of batteries across multiple scales to propel the research on rechargeable batteries for the next generation ***,phase information,and lattice of energy materials in both two dimensions and three dimensions can be intuitively obtained through the utilization of x-ray imaging ***,x-ray imaging technology is increasingly gaining attention due to its non-destructive nature and high penetrative capability,enabling in situ experiments and multi-scale spatial *** this review,we initially overview the basic principles and characteristics of several key x-ray imaging *** x-ray imaging technology is tailored to specific application ***,examples of multi-scale implementations of x-ray imaging technologies in the field of rechargeable batteries are *** review is anticipated to augment the comprehension of readers for x-ray imaging techniques as well as to stimulate the development of novel concepts and approaches in rechargeable battery research.

关键词： battery dimensions charge

Fundamentals,preparation,and mechanism understanding of Li/Na/Mg-Sn alloy anodes for liquid and solid-state lithium batteries and beyond

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Nano Research 2023年第6期16卷 8191-8218页

作者： Amardeep Amardeep Donald JFreschi jiajun wang Jian Liu School of Engineering Faculty of Applied Sciencethe University of British ColumbiaKelownaBC V1V 1V7Canada Fenix Advanced Materials Trail BCV1R 2T3Canada MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage School of Chemistry and Chemical EngineeringHarbin Institute of TechnologyHarbin 150001China

Lithium metal is one of the most promising anodes to develop high energy density and safe energy storage devices due to its highest theoretical capacity(3860 mAh·g^(−1))and lowest electrochemical potential,demonstrating great potential to fulfill unprecedented demand from electronic gadgets,electric vehicles,and grid *** these good merits,lithium metal suffers from low Coulombic efficiency and dendritic growth,leading to internal short-circuiting of the cell and raising safety concerns about employing lithium metal as an ***,lithium-tin(Li-Sn)alloys,among other lithium alloys,have emerged as a potential alternative to lithium metal to efficiently suppress the lithium dendrite formation and reduce interfacial resistance for safer and longer-lasting lithium ***,this work first reviews the fundamentals of Li-Sn alloys,and critically analyzes the failure mechanisms of pristine Li-metal anode and how Li-Sn alloys could overcome those *** subsequent section examines various strategies to synthesize Li-Sn bulk and protection film alloys,followed by an evaluation of symmetric cell ***,the comparative electrochemical performance of full cells against different cathodes and solid electrolytes provides an overview of the present ***,advanced characterization techniques were discussed to visualize lithium dendrites directly and quantify the mechanical performance of Li-Sn *** but not the least,the state-of-the-art progress of applying M-Sn(M=Na and Mg)beyond lithium batteries was *** closing,this work identifies the critical challenges and provides future perspectives on Li-Sn alloy for lithium batteries and beyond.

关键词： Li-Sn alloys fundamental studies dendrite-free anodes liquid/solid-state batteries Li-Sn alloys synthesis approachescum-electrochemical performance lithium batteries and beyond

Methane emissions during storage of different treatments from cattle manure in Tianjin

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Journal of Environmental Sciences 2010年第10期22卷 1564-1569页

作者： jiajun wang Chiqing Duan Yaqin Ji Yichao Sun . College of Environmental Science and Engineering Nankai University Iianjin 300071 China. State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control Tianjin 300071 China Institute of Environment and Ecology Tianjin Academy of Environmental Sciences Tianjin 300191 China

Many studies on methane emissions from animal manure have revealed that animal manure is a major source of methane emissions to the atmosphere that can have negative consequences for people, animals and environment. In general, the release of methane can be influenced by the type of feed taken by animals, temperature, manure characteristics and so on. This study aimed at quantifying and comparing methane release from dairy manure with different piling treatments. Four treatments were designed including manure piling height 30, 45, 60 cm and adding 6 cm manure every day until the piling height was 60 cm. Static chamber method and gas chromatography were adopted to measure the methane emissions from April to June in 2009. Methane emission rates of all four manure treatments were low in the first week and then increased sharply until reaching the peak values. Subsequently, all the methane emission rates decreased and fluctuated within the steady range till the end of the experiment. Wilcoxon nonparametfic tests analysis indicated that methane emission rate was greatly influenced by manure piling height and manner. There were no significant relationships between methane emission rates and the temperatures of ambience and heap. However, regression analysis showed that the quadratic equations were found between emission rates of all treatments and the gas temperature in the barrels.

关键词： dairy manure storage methane emissions different piling treatments

Experimental investigation on degradation mechanism of membrane electrode assembly at different humidity under automotive protocol

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Chinese Journal of Chemical Engineering 2023年第4期56卷 70-79页

作者： jiajun wang Wenbin Yang Jiangtao Geng Zhigang Shao Wei Song Fuel Cell System and Engineering Laboratory Key Laboratory of Fuel Cells and Hybrid Power SourcesDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China University of Chinese Academy of Sciences Beijing 100039China

Humidity can affect the attenuation of MEA(membrane electrode assembly), however, the relationship between humidity and MEA decays is complex and ambiguous in realistic application. Herein, we design a simulating automotive protocol, performed on five single fuel cells under RH(relative humidity) 100%,RH 80%, RH 64%, and RH 40%, RH 10%, respectively, to study the relationship of MEA decays and humidity and suggest optimized humidity range to extend the durability. With the electrochemical impedance spectroscopy, cyclic voltammetry, X-ray fluorescence, X-ray diffraction, transmission electron microscope, X-ray photoelectron spectroscopy, the four degradation mechanisms about catalyst layer, including Pt dissolution, Pt coarsening, carbon corrosion and ionomer degradation, are observed. Pt coarsening and carbon corrosion are accelerated by higher water content at high humidity. Ionomer degradation and Pt dissolution are enhanced in low humidity. With the linear sweep voltammetry, ion chromatography,nuclear magnetic resonance, tensile test and scan electron microscope, chemical and mechanical degradation in proton exchange membrane are all observed in these five fuels. Chemical degradation, characterized by membrane thinning and more fluoride loss, occurred markedly in RH 10%. Mechanical degradation, characterized by the non-uniformity thickness and bad mechanical properties, is more pronounced in RH 100%, RH 80%, RH 64%. These two degradations are in a moderate level in RH 40%. The research suggests that the RH range from 64% to 40% is conductive to mitigate the degradation of MEAs operated in automotive applications.

关键词： Fuel cell Simulating automotive protocol Relative humidity Degradation Membrane

Visible light-driven oxidant-free dehydrogenation of alcohols in water using porous ultrathin g-C_(3)N_(4)nanosheets

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Green Energy & Environment 2022年第4期7卷 712-722页

作者： Wei Zhang jiajun wang Zewei Liu Yibing Pi Rong Tan National&Local Joint Engineering Laboratory for New Petro-chemical Materials and Fine Utilization of Resources Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research(Ministry of Education)College of Chemistry and Chemical EngineeringHunan Normal UniversityChangsha410081China

Graphitic carbon nitride(g-C_(3)N_(4)) is a fascinating photocatalyst for solar energy utilization in ***,it often suffers from moderate photo-catalytic activity due to its low specific surface area and fast recombination rate of photogenerated electrons upon ***,we overcome the bottlenecks by constructing a porous g-C_(3)N_(4) nanosheet(PCNS)through a simple thermal oxidation etching *** from its porous layer structure,the obtained PCNS exhibits large specific surface area,efficient separation of photogenerated charge carriers,as well as high exposure of active *** a result,it is robust and universal in visible light-driven dehydrogenation of alcohols in water under oxidant-free *** quantitative yields(>99%)of various valuable carbonyl compounds were obtained over PCNS,while bulk g-C_(3)N_(4) was far less ***,the photo-catalyst was highly stable and could be facilely recovered from the aqueous system for efficient *** easy preparation and excellent performance made PCNS a promising and competitive photocatalyst for the solar applications.

关键词： Photo-catalysis Porous g-C_(3)N_(4)nanosheets Visible light irradiation Oxidant-free dehydrogenation Alcohols