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Visualization of enantioselective recognition and separation of chiral acids by aggregation-induced emission chiral diamine

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Aggregate 2023年第3期4卷 144-152页

作者： Chunxuan Qi Keyue Wei Qingyang li Yuemei li Xiaolong Su Jun-Cheng Yang Jingjing Tian pu Chen Hai-Tao Feng Ben Zhong Tang AIE Research Center Shaanxi Key Laboratory of PhytochemistryCollege of Chemistry and Chemical EngineeringBaoji University of Arts and SciencesBaojiChina Shenzhen Institute of Molecular Aggregate Science and Engineering School of Science and EngineeringThe Chinese University of Hong Kong-ShenzhenShenzhenChina

Enantioselective recognition and separation are the most important issues in the fields of chemistry,pharmacy,agrochemical,and food ***,we developed two optically active diamines showing aggregation-induced emission(AIE)that can discriminate 5 kinds of chiral acids with high ***,a very high fluorescence intensity ratio(IL/ID)of 281 for(±)-Dibenzoyl-D/L-tartaric acid was obtained through the collection of fluorescence change after interaction with chiral AIE-active *** virtue of AIE property and intermolecular acidbase interaction,enantioselective separation was facilely realized by simple filtration of the precipitates formed by chiral AIE luminogen(AIEgen)and one enantiomer in the racemic *** chiral HPLC data indicated that the precipitates of AIEgen/chiral acid possessed 82%L-analyte(the enantiomeric excess value was assessed to be 64%ee).Therefore,this method can serve as a simple,convenient,and low-cost tool for chiral detection and separation.

关键词： acid−base interaction aggregation-induced emission chirality enantioselective recognition fluorescent probe

Dynamical Influence of Nodes Revisited: A Markov Chain Analysis of Epidemic Process on Networks

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Chinese Physics Letters 2012年第4期29卷 248-251页

作者： li Ping ZHANG Jie xu Xiao-Ke SMALL Michael Center for Networked Systems School of Computer ScienceSouthwest Petroleum UniversityChengdu 610500 State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu 610500 Center for Computational Systems Biology Fudan UniversityShanghai 200433 Hong Kong Polytechnic University Hung HomKowloonHong Kong School of Communication and Electronic Engineering Qingdao Technological UniversityQingdao 2665206 School of Mathematics and Statistics University of Western AustraliaCrawleyWA 6009Australia

We provide a theoretical analysis of node importance from the perspective of dynamical processes on *** particular,using Markov chain analysis of the susceptible-infected-susceptible (SIS) epidemic model on networks,we derive the node importance in terms of dynamical behaviors on network in a theoretical *** is found that this quantity happens to be the eigenvector centrality under some conditions,which bridges the topological centrality measure of the nodes with the dynamical influence of the nodes for the dynamical *** furthermore discuss the condition under which the eigenvector centrality is valid for dynamical phenomena on networks.

关键词： process dynamical eigenvector

High-throughput metagenomic analysis of petroleum-contaminated soil microbiome reveals the versatility in xenobiotic aromatics metabolism

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Journal of Environmental Sciences 2017年第6期29卷 25-35页

作者： Yun-Juan Bao Zixiang xu Yang li Zhi Yao Jibin Sun Hui Song National Engineering Laboratory for Industrial Enzymes Chinese Academy of SciencesTianjin 300308China Key Laboratory of Systems Microbial Biotechnology Chinese Academy of SciencesTianjin 300308China Tianjin Institute of Industrial Biotechnology Chinese Academy of SciencesTianjin 300308China Key Laboratory of Immune Microenuironment and Disease of the Ministry of Education Tianjin Medical UniversityTianjin 300070China W.M.Keck Center for Transgene Research University of Notre DameNotre DameIN 46556USA

The soil with petroleum contamination is one of the most studied soil ecosystems due to its rich microorganisms for hydrocarbon degradation and broad applications in bioremediation. However, our understanding of the genomic properties and functional traits of the soil microbiome is limited. In this study, we used high-throughput metagenomic sequencing to comprehensively study the microbial community from petroleum-contaminated soils near Tianjin Dagang oilfield in eastern China. The analysis reveals that the soil metagenome is characterized by high level of community diversity and metabolic versatility. The metageome community is predominated by 7-Proteobacteria and a-Proteobacteria, which are key players for petroleum hydrocarbon degradation. The functional study demonstrates over-represented enzyme groups and pathways involved in degradation of a broad set of xenobiotic aromatic compounds, including toluene, xylene, chlorobenzoate, aminobenzoate, DDT, methylnaph- thalene, and bisphenol. A composite metabolic network is proposed for the identified pathways, thus consolidating our identification of the pathways. The overall data demon- strated the great potential of the studied soil microbiome in the xenobiotic aromatics degradation. The results not only establish a rich reservoir for novel enzyme discovery but also provide putative applications in bioremediation.

关键词： Comparative genomicsMetagenomic sequencingTaxonomic analysisOil-contaminated soils

Reconceptualizing kinesin＇s working cycle as separate chemical and mechanical processes

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Frontiers of physics 2018年第5期13卷 153-163页

作者： Hui-Juan xu Tong Tong Rui-Zheng Hou Hong-Rong li School of Science Xi'an Jiaotong University Xi'an 710049 China Institute of Quantum Optics and Quantum Information Xi'an Jiaotong University Xi'an 710049 China

The biomolecular motor kinesin uses chemical energy released from a fuel reaction to generate di- rectional movement and produce mechanical work. The underlying physical mechanism is not fully understood yet. To analyze the energetics of the motor, we reconceptualize its chemomechanical cy- cle in terms of separate fuel reaction and work production processes and introduce a thermodynamic constraint to optimize the cycle. The model predicts that the load dependences of the motor＇s veloc- ity, stepping ratio, and dwell time are determined by the mechanical parameters of the motor-track system rather than the fuel reaction rate. This behavior is verified using reported experimental data from wild-type and elongated kinesins. The fuel reaction and work production processes indicate that kinesin is driven by switching between two chemical states, probably following a general pattern for molecular motors. The comparison with experimental data indicates that the fuel reaction processes are close to adiabatic, which is important for efficient operation of the motor. The model also suggests that a soft, short neck linker is important for the motor to maintain its load transport velocity.

关键词： kinesin chemomechanical coupling thermodynamics entropy production

2-kW-level superfluorescent fiber source with flexible wavelength and linewidth tunable characteristics

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High Power Laser Science and Engineering 2021年第4期9卷 93-102页

作者： Jun Ye Chenchen Fan Jiangming xu Hu Xiao Jinyong Leng pu Zhou College of Advanced Interdisciplinary Studies National University of Defense TechnologyChangsha 410073China

The superfluorescent fiber source(SFS)with tunable optical spectrum has shown great application potential in the sensing,imaging,and spectral ***,we demonstrate for the first time a 2-kW-level wavelength and linewidth tunable *** on a flexible filtered SFS seed and three stages of fiber amplifiers,the output power can be scaled from the milliwatt level to about 2 kW,with a wavelength tuning range of 1068–1092 nm and a linewidth tuning range of 2.5–9.7 ***,a numerical simulation is conducted based on the generalized nonlinear Schr?dinger equation,and the results reveal that the wavelength tuning range is limited by the decrease of seed power and the growth of amplified spontaneous emission,whereas the linewidth tuning range is determined by the gain competition and nonlinear Kerr *** developed wavelength and linewidth tunable SFS may be applied to scientific research and industrial processing.

关键词： fiber amplifiers high power superfluorescent fiber source tunable lasers

Prevalence of class 1 integron and its gene cassettes carrying antibiotic resistance genes in drinking water treatment and distribution systems

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Frontiers of Environmental Science & Engineering 2024年第10期18卷 115-126页

作者： Shengnan liu Zihan li Yan Shen Shuyu Jia Peng liu xu-Xiang Zhang State Key Laboratory of Pollution Control and Resource Reuse School of the EnvironmentNanjing UniversityNanjing 210023China College of Resources and Environmental Sciences Nanjing Agricultural UniversityNanjing 210095China

Class 1 integrons are vital mobile genetic elements involved in the environmental transmission of antibiotic resistance genes(ARGs).However,knowledge about the diversity and abundance of class 1 integrons and gene cassettes during drinking water treatment and distribution is still *** this study,we aimed to uncover the prevalence of class 1 integrons in the drinking water treatment and distribution systems with the combination of culture-dependent and culture-independent ***,we applied the nanopore sequencing method to characterize the diversity and arrangement of ARGs carried by class 1 integron-associated gene cassettes.A total of 42 isolates were inti-positive among the 208 strains isolated from drinking water,which tended to confer multi-drug resistance compared with intll-negative *** absolute abundance of the intl1 average i.15×10^(9) copies/L in the source water and underwent the most significant reduction of over 99.9% after liquid chiorine ***,nanopore sequencing revealed that the class 1 integron-associated gene cassettes carried 51 subtypes of ARGs in drinking water,mainly conferring resistance to aminoglycosides and *** treatment processes,especially liquid chlorine disinfection,reduced most of the ARGs carried by gene cassettes,though some of the ARG subtypes persisted along the treatment and distribution ike aac(6)-Il,aadA,and *** antibiotic resistance gene cassette array laac(6')-Ⅱ arr was most frequently detected,especially in the chlorinated *** study underlined that drinking water was potential reservoir for integron-mediated ARGs transfer,indicating that the health risks of resistance gene cassettes in class 1 integrons deserved urgent attention.

关键词： Class 1 integron Antibiotic resistance genes Drinkingwater Genecassettearrays liquid chlorine disinfection

Carbon-based bifunctional electrocatalysts for oxygen reduction and oxygen evolution reactions:Optimization strategies and mechanistic analysis

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Journal of Energy Chemistry 2022年第8期31卷 234-265,I0008页

作者： Huidong xu Jack Yang Riyue Ge Jiujun Zhang Ying li Mingyuan Zhu liming Dai Sean li Wenxian li Institute of Materials Shanghai University School of Materials Science and Engineering UNSW Materials and Manufacturing Futures InstituteUniversity of New South Wales Institute for Sustainable Energy Shanghai University School of Chemical Engineering University of New South Wales Shanghai Key Laboratory of High Temperature Superconductors

Electrocatalysts are one of the essential components for the devices of high-efficiency green energy storage and conversion,such as metal-air cells,fuel cells,and water electrolysis *** catalysts made from noble metals possess high catalytic performance in both oxygen reduction reaction(ORR)and oxygen evolution reaction(OER),their scarcity and expensiveness significantly limit large-scale *** this regard,metal-free/non-noble metal carbon-based catalysts have become competitive alternatives to replace catalysts made of noble ***,low catalytic ORR/OER performance is the challenge of carbon-based catalysts for the commercial applications of metal-air *** solve the problem of poor catalytic performance,two strategies have been proposed:(1)controlling the microstructure of the catalysts to expose more active sites as the channels of rapid mass and electron transfer;and(2)reducing the reaction energy barrier by optimizing the electronic structures of the catalysts via surface ***,we review different types of bifunctional ORR/OER electrocatalysts with the activated surface *** focus on how the challenge can be overcome with different methods of material synthesis,structural and surface characterization,performance validation/optimization,to outline the principles of surface modifications behind catalyst *** particular,we provide critical analysis in the challenges that we are facing in structural design and surface engineering of bifunctional ORR/OER catalysts and indicate the possible solution for these problems,providing the society with clearer ideas on the practical prospects of noble-metal-free electrocatalysts for their future applications.

关键词： Electrocatalyst Bifunctionality Oxygen reduction Oxygen evolution Carbons transition metals Surface engineering Microstructure

Prediction for Flow Stress of 95CrMo Hollow Steel During Hot Compression

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Acta Metallurgica Sinica(English Letters) 2017年第3期30卷 250-260页

作者： Bao-Sheng Xie Qing-Wu Cai Wei Yu li-Xiong xu Zhen Ning Collaborative Innovation Center of Steel Technology University of Science and Technology Beijing Beijing 100083 China National Engineering Research Center of Advanced Rolling University of Science and Technology Beijing Beijing 100083 China

The compressive deformation behavior of 95CrMo hypereutectic steel was studied at temperatures ranging from 800 to 1050 ℃ and strain rates from 0.1 to 3 s-1 on a Gleeble-3500 thermo-simulation machine. The results showed that, with the decrease in deformation temperature and increase in strain rate, the fragmented retained austenite in finer and distributed more uniformly in the ferrite matrix as a result of the inhibited recovery. The recorded flow stress suggested that the stress level decreases with increasing temperature and decreasing strain rate. Based on the classical stress-dislocation relation, the constitutive equations of flow stress determined by work-hardening and softening mechanisms were estab- lished. A comparison between the experimental and calculated values confirmed the reliability of the model, and the predictability of the model was also quantified in terms of correlation coefficients and average absolute relative errors, which were found generally above 0.99 and below 2.50%, respectively. In the whole range of strain rate, the activation energy is 419.84 kJ/mol. By further identification based on Sch6ck＇s model and Kocks-Argon-Ashby model, the rate- controlling mechanism is found to be dislocation cross-slip.

关键词： Tempering 95CrMo hypereutectic steel Hot deformation behavior Hot compression Rate-controlling mechanism Constitutive model

The Electronic Structure and Formation Energies of Ni-doped CuAlO2 by Density Functional Theory Calculation

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Chinese Physics Letters 2014年第3期31卷 118-121页

作者： xu Ying li Fei SHENG Wei NIE Guo-Zheng YUAN Ding-Wang School of Physics Hunan University of Science and Technology Xiangtan 411202 Department of Education Science Hunan First Normal University Changsha 410205 College of Materials Science and Engineering Hunan University Changsha 410082

The electronic structure and formation energies of Ni-doped CuAlO2 are calculated by first-principles calculations. Our results show that Ni is good for p-type doping in CuAlO2. When Ni is doped into CuAlO2, it prefers to substitute Al-site. NiAl is a shallow acceptor, while NiCu is a deep acceptor and its formation energy is high. Further electronic structure calculations show that strong hybridization happens between Ni-3d and O-2p states for Ni substituting Al-site, while localized Ni-3d states are found for Ni substituting Cu-site.

关键词： SEMICONDUCTOR doping RESEARCH DENSITY functional theory FERMI energy ELECTRONIC structure -- Research PHYSICS research