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Minimal least eigenvalue of connected graphs of order n and size m=n+k(5≤k≤8)

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Frontiers of Mathematics in China 2019年第6期14卷 1213-1230页

作者： Xin LI Jiming GUO zhiwen wang Department of Mathematics Bast China University of Science and TechnologyShanghai 200237China

The least eigenvalue of a connected graph is the least eigenvalue of its adjacency *** characterize the connected graphs of order n and size n+k(5≤k≤8 and n≥k+5)with the minimal least eigenvalue.

关键词： Least eigenvalue adjacency matrix graph

An international comprehensive benchmarking analysis of synthetic biology in China from 2015 to 2020

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Chinese Journal of Chemical Engineering 2022年第8期35卷 211-226页

作者： Meiru Jiang Cong Chen Tao Chen Chao Zhao zhiwen wang Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering(Ministry of Education) SynBio Research PlatformCollaborative Innovation Center of Chemical Science and Engineering(Tianjin)School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China Center for Biosafety Research and Strategy Tianjin UniversityTianjin 300072China

As a new interdisciplinary field,synthetic biology has led to valuable innovations in the fields of medicine,chemistry,agriculture,energy and *** this paper,we systematically review the development status of global synthetic biology in the past six years,and make an in-depth benchmarking analysis of the field in *** the aid of Scopus and SciVal,we analyze the scholarly output of synthetic biology in the world and individual countries,including publication distribution,popular journals and eminent ***,the research focus and concepts,citation impact and collaborations are also examined using numerical index methods such as the field-weighted citation impact(FWCI)and relative activity index(RAI),showing the differences between data more *** study aims to offer a comprehensive understanding of the research status of synthetic biology in China and the world,offering a benchmarked overview of the results as a reference to guide the development of this field in the future.

关键词： Synthetic biology Scopus SciVal Output Citation impact Collaboration

Multi-modular metabolic engineering of heme synthesis in Corynebacterium glutamicum

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Synthetic and Systems Biotechnology 2024年第2期9卷 285-293页

作者： Qiuyu Yang Xi Sun Hong wang Tao Chen zhiwen wang Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering(Ministry of Education) Tianjin UniversityTianjin300072China SynBio Research Platform Collaborative Innovation Center of Chemical Science and Engineering(Tianjin)School of Chemical Engineering and TechnologyTianjin UniversityTianjin300072China School of Life Science Ningxia UniversityYinchuan750021China

Heme,an iron-containing porphyrin derivative,holds great promise in fields like medicine,food production and ***,we developed an engineered Corynebacterium glutamicum strain for efficient heme production by combining modular engineering and RBS *** whole heme biosynthetic pathway was methodically divided into 5-ALA synthetic module,uroporphyrinogen III(UPG III)synthetic module and heme synthetic module for further construction and *** heme synthetic modules were compared and the siroheme-dependent(SHD)pathway was identified to be optimal in *** for the first *** further improve heme production,the expression of genes in UPG III synthetic module and heme synthetic module was coordinated optimized through RBS engineering,***,heme oxygenase was knocked out to reduce heme *** engineered strain HS12 showed a maximum iron-containing porphyrin derivatives titer of 1592 mg/L with the extracellular secretion rate of 45.5%in fed-batch *** study constructed a *** chassis strain for efficient heme accumulation,which was beneficial for the advancement of efficient heme and other porphyrins production.

关键词： Corynebacterium glutamicum Heme Biosynthetic pathways Metabolic engineering

The Least Eigenvalue of Unicyclic Graphs with Application to Spectral Spread

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Algebra Colloquium 2022年第2期29卷 265-272页

作者： Jiming Guo Gege Zhang zhiwen wang Panpan Tong School of Mathematics East China University of Science and Technology Shanghai 200237China

Let U^(g)_(n)be the set of connected unicyclic graphs of order n and girth *** C(T_(1),T_(2),…,T_(g))∈U^(g)_(n)be obtained from a cycle v_(1)v_(2)…v_(g)v_(1)(in an anticlockwise direction)by identifying v_(i)with the root of a rooted tree T_(i)of order n_(i)for each i=1,2,…,g,where n_(i)≥1 and∑^(g)_(i=1)n_(i)=*** this note,the graph with the minimal least eigenvalue(and the graph with maximal spread)in C(T_(1),T_(2),…,T_(g))is determined.

关键词： adjacency matrix least eigenvalue eigenvector unicyclic graph

Surface functionalized Pt/SnNb_(2)O_(6)nanosheets for visible-light-driven the precise hydrogenation of furfural to furfuryl alcohol

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Journal of Energy Chemistry 2022年第3期31卷 566-575,I0015页

作者： Yingzhang Shi Huan wang zhiwen wang Cheng Liu Mingchuang Shen Taikang Wu Ling Wu State Key Laboratory of Photocatalysis on Energy and Environment Fuzhou UniversityFuzhou 350116FujianChina State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of ScienceFuzhou 350002FujianChina

Photocatalytic upgrading of renewable biomass is a promising way to relieve energy crisis and environmental ***,low photocatalytic efficiency and uncontrollable selectivity still limit its ***,ultrathin SnNb_(2)O_(6)nanosheets with high dispersed Pt nanoparticles(Pt/SN)were successfully developed as an efficient photocatalyst for the precise hydrogenation of furfural(FUR)to furfuryl alcohol(FOL)under visible light irradiation and exhibited the high conversion of FUR(99.9%)with the high selectivity for FOL(99.9%).It was revealed that SN with only 4.1 nm thickness possess good separation ability of photo-generated carriers and abundant surface Lewis acid sites(Nb^(5+))which would selectively chemisorb and activate FUR molecules via the Nb···O=C ***,Pt nanoparticles would gather photo-generated electrons for greatly promoting the generation of active H species to support the hydrogenation of FUR to *** synergistic effects between SnNb_(2)O_(6)nanosheets and Pt nanoparticles remarkably facilitate the photocatalytic performance for *** work not only confirms the great potential of ultrathin nanosheet photocatalyst with functional metal sites for precise upgrading of biomass but also provides an in-depth view to understand the surface/interface interaction between reactant molecules and surface sites of a photocatalyst.

关键词： Biomass conversion Hydrogenation of furfural Two-dimensional materials Sn2NbO6 nanosheet Pt nanoparticle Photocatalysis

New Zircon U-Pb Age of Late Devonian Tuff in Guangxi, South China and the Significance for the Paleo-Tethys Branch Ocean

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Acta Geologica Sinica(English Edition) 2018年第1期92卷 402-403页

作者： HU Lisha DU Yuansheng XU Yajun wang zhiwen wang Chenghao Collage of Marine Geosciences Key Laboratory of Submarine Geosciences and Prospecting Technology Ocean University of China Laboratory for Marine Geology Qingdao National Laboratory for Marine Science and Technology (QNLM) State Key Laboratory of Biogeology and Environmental Geology China University of Geosciences

Objective The eastern extending range of the Paleo-Tethys Ocean in southwest China has always been focused and controversial. At the beginning of this century some scholars proposed that the Paleo-Tethys Branch Ocean may extend to the Babu-Pingxiang and Cengxi areas along the stouthwestern margin of the South China Block （Cai and Zhang, 2009）. However, the pivotal proof of Late Paleozoic ophoilite and magmatic rocks was absent or sporadical in the Guangxi Zhuang Autonomous Region, resulting in insufficient evidence to support this viewpoint. For the first time this work reported the Late Devonian tuff in the Qinzhou area in the south of the Guangxi Zhuang Autonomous Region and conducted zircon U-Pb dating on it in order to constrain the extension of the Paleo-Tethys Ocean in the South China Block.

关键词： the Paleo-Tethys Branch Ocean New Zircon U-Pb Age of Late Devonian

A precision-drive hysteresis model with an equal-density weight function for GMA feedforward compensation

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Nanotechnology and Precision Engineering 2023年第2期6卷 13-24页

作者： Kun Xiao zhiwen wang Hongyuan wang Jie Sun Yelong Zheng Yinguo Huang State Key Laboratory of Precision Measuring Technology and Instruments Tianjin UniversityTianjin 300072China

Giant magnetostrictive actuators(GMAs) are a widely used type of micro-nano actuator, and they are greatly significant in the field of precision engineering. The accuracy of a GMA often depends on its hysteresis model. However, existing models have some limitations,including the difficulty of identifying their parameters and the tradeoff between the quantity of modeling data required and the level of precision achieved. To solve these problems, in this paper, we propose a Preisach inverse model based on equal-density segmentation of the weight function(E-Preisach). The weight function used to calculate the displacement is first discretized. Then, to obtain a finer weight distribution, the discretized geometric units are uniformly divided by area. This can further minimize the output displacement span, and it produces a higher-precision hysteresis model. The process of parameter identification is made easier by this approach, which also resolves the difficulty of obtaining high precision using a small amount of modeling data. The Preisach and the E-Preisach inverse models were investigated and compared using experiments. At frequencies of 1 and 5 Hz, it was found that the E-Preisach inverse model decreases the maximum error of the feedforward compensation open-loop control to within 1 μm and decreases the root-mean-square error in displacement to within0.5 μm without the need to increase the number of measured hysteresis loops. As a result, the E-Preisach inverse model streamlines the structure of the model and requires fewer parameters for modeling. This provides a high-precision modeling method using a small amount of modeling data;it will have applications in precision engineering fields such as active vibration damping and ultra-precision machining.

关键词： Micro-nano actuator GMA Hysteresis model Preisach model

Efficient acetoin production from pyruvate by engineered Halomonas bluephagenesis whole-cell biocatalysis

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Frontiers of Chemical Science and Engineering 2023年第4期17卷 425-436页

作者： Meiyu Zheng Zhenzhen Cui Jing Zhang Jing Fu zhiwen wang Tao Chen Department of Biochemical Engineering School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300350China Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering(Ministry of Education) School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300350China Department of Biology and Biological Engineering Chalmers University of TechnologyGothenburg 41296Sweden

Acetoin is an important platform chemical,which has a wide range of applications in many *** bluephagenesis,a chassis for next generation of industrial biotechnology,has advantages of fast growth and high tolerance to organic acid salts and alkaline ***,α-acetolactate synthase andα-acetolactate decarboxylase from Bacillus subtilis 168 were co-expressed in *** to produce acetoin from *** reaction condition optimization and further increase ofα-acetolactate decarboxylase expression,acetoin production and yield were significantly enhanced to 223.4 mmol·L^(-1) and 0.491 mol·mol^(-1) from 125.4 mmol·L^(-1) and 0.333 mol·mol^(-1),***,the highest titer of 974.3 mmol·L^(-1)(85.84 g·L^(-1))of acetoin was accumulated from 2143.4 mmol·L^(-1)(188.6 g·L^(-1))of pyruvic acid within 8 h in fed-batch bioconversion under optimal reaction ***,the reusability of the cell catalysis was also tested,and the result illustrated that the whole-cell catalysis obtained 433.3,440.2,379.0,442.8 and 339.4 mmol·L^(-1)(38.2,38.8,33.4,39.0 and 29.9 g·L^(-1))acetoin in five repeated cycles under the same *** work therefore provided an efficient *** whole-cell catalysis with a broad development prospect in biosynthesis of acetoin.

关键词： acetoin pyruvate α-acetolactate synthetase α-acetolactate decarboxylase Halomonas bluephagenesis whole-cell biocatalysis

Replication of large area nanoimprint stamp with small critical dimension loss

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Science China(Technological Sciences) 2012年第3期55卷 600-605页

作者： MENG FanTao GUAN Le wang zhiwen HAN ZhiTao CHU JinKui Key Laboratory for Precision and Non-traditional Machining Technology of Ministry of Education Dalian University of TechnologyDalian 116024China Key Laboratory for Micro/Nano Technology and System of Liaoning Province Dalian University of TechnologyDalian 116024China

In this paper,the replication process of large area nanoimprint stamp with small critical dimension(CD) loss was investigated,using the thin residual layer nanoimprint lithography(NIL) *** residual layer thickness was optimized by changing the spin-coated resist *** dependences of the residual layer etching rate on gas flow,chamber pressure,and RF power were investigated,and the optimized process conditions were *** means of the thin residual layer NIL technique and optimized residual layer etching process,large area stamp with small CD loss and multi-orientation patterns was successfully replicated on 2-inch SiO2/Si *** CD loss was controlled within 5 *** replicated stamp showed high performance in the patterning with thermal *** replication process reported in this work could also be used to fabricate large area nanostructures with small CD loss.

关键词： nanoimprint stamp replication small critical dimension loss nanoimprint lithography multi-orientation patterns