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Characterization of a new smog chamber for evaluating SAPRC gas-phase chemical mechanism

Journal of Environmental Sciences 2020年第9期32卷 14-22页

作者： Kangwei Li Chao Lin Chunmei Geng Stephen White Linghong Chen Zhier Bao Xin Zhang Yanyun Zhao Lixia Han Wen Yang Merched Azzi State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China State Key Laboratory of Clean Energy Utilization Zhejiang UniversityHangzhou 310027China CSIRO Energy North RydeNSW 1670Australia New South Wales Department of Planning Industry and EnvironmentLidcombeNSW 1825Australia

A new state-of-the-art indoor smog chamber facility(CAPS-ZJU) has been constructed and characterized at Zhejiang University,which is designed for chemical mechanism evaluation under well-controlled conditions.A series of characterization experiments were performed to validate the well-established experimental protocols,including temperature variation pattern,light spectrum and equivalent intensity(JNO2),injection and mixing performance,as well as gases and particle wall loss.In addition,based on some characterization experiments,the auxiliary wall mechanism has been setup and examined.Fifty chamber experiments were performed across a broad range of experimental scenarios,and we demonstrated the ability to utilize these chamber data for evaluating SAPRC chemical mechanism.It was found that the SAPRC-11 can well predict the 03 formation and NO oxidation for almost all propene runs,with 6 hr △(O3-NO) model error of-3%±7%,while the final O3 was underestimated by-20% for isoprene experiments.As for toluene and p-xylene experiments,it was confirmed that SAPRC-11 has significant improvement on aromatic chemistry than earlier version of SAPRC-07,although the aromatic decay rate was still underestimated to some extent.The model sensitivity test has been carried out,and the most sensitive parameters identified are the initial concentrations of reactants and the light intensity as well as HONO offgasing rate and 03 wall loss rate.All of which demonstrated that CAPS-ZJU smog chamber could derive high quality experimental data,and could provide insights on chamber studies and chemical mechanism development.

关键词： mechanism chemical CAPS

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chemical Concepts from Density Functional Theory

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物理化学学报 2018年第6期34卷 563-566页

作者： LIU Shubin ZHANG Xiaojuan Research Computing Center University of North Carolina Chapel Hill NC 27599-3420 USA Editorial Office ofActa Physico-Chimica Sinica College of Chemistry and Molecular Engineering Peking University Beijing 100871 E R. China.

chemical concepts such as structure,bonding,reactivity,etc.have been widely used in the literature and text books to appreciate molecular properties and chemical transformations.Even though modern theoretical and computational chemistry is well established from the perspective of accuracy and complexity,how to quantify these concepts is a still unresolved task.Conceptual density functional theory and its related recent developments provide unique opportunities to tackle this problem.In this Special Issue,27 contributions from top investigators over the world are collected to highlight the state-of-art research on this topic,which not only showcases the status of where we are now but also unveils a number to possible future directions to be pursued.

关键词： chemical Concepts Density Functional Theory

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Infrared chemical imaging through non-degenerate two-photon absorption in silicon-based cameras

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Light(Science & Applications) 2020年第1期9卷 813-822页

作者： David Knez Adam M.Hanninen Richard C.Prince Eric O.Potma Dmitry A.Fishman Department of Chemistry University of CaliforniaIrvineCA 92697USA Department of Biomedical Engineering University of CaliforniaIrvineCA 92697USA

chemical imaging based on mid-infrared(MIR)spectroscopic contrast is an important technique with a myriad of applications,including biomedical imaging and environmental monitoring.Current MIR cameras,however,lack performance and are much less affordable than mature Si-based devices,which operate in the visible and nearinfrared regions.Here,we demonstrate fast MIR chemical imaging through non-degenerate two-photon absorption(NTA)in a standard Si-based charge-coupled device(CCD).We show that wide-field MIR images can be obtained at 100 ms exposure times using picosecond pulse energies of only a few femtojoules per pixel through NTA directly on the CCD chip.Because this on-chip approach does not rely on phase matching,it is alignment-free and does not necessitate complex postprocessing of the images.We emphasize the utility of this technique through chemically selective MIR imaging of polymers and biological samples,including MIR videos of moving targets,physical processes and live nematodes.

关键词： absorption Infrared chemical

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Nanoscale chemical imaging of individual chemotherapeutic cytarabineloaded liposomal nanocarriers

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Nano Research 2019年第1期12卷 197-203页

作者： Karin Wieland Georg Ramer Victor U. Weiss Guenter Allmaier Bemhard Lendl Andrea Centrone Institute of chemical Technologies and Analytics Research Division EnvironmentalProcess Analytics and SensorsTU WienVienna 1060Austria Center for Nanoscale Science and Technology National Institute of Standards and TechnologyGaithersburgMD 20899USA Institute for Research in Electronics and Applied Physics University of MarylandCollege ParkMD 20742USA Institute of chemical Technologies and Analytics Research Division Instrumental and Imaging Analytical ChemistryTU WienVienna 1060Austria

Dosage of chemotherapeutic drugs is a tradeoff between efficacy and side-effects.Liposomes are nanocarriers that increase therapy efficacy and minimize side-effects by delivering otherwise difficult to administer therapeutics with improved efficiency and selectivity.Still,variabilities in liposome preparation require assessing drug encapsulation efficiency at the single liposome level,an information that,for non-fluorescent therapeutic cargos,is inaccessible due to the minute drug load per liposome.Photothermal induced resonance (PTIR) provides nanoscale compositional specificity,up to now,by leveraging an atomic force microscope (AFM) tip contacting the sample to transduce the sample's photothermal expansion.However,on soft samples (e.g.,liposomes) PTIR effectiveness is reduced due to the likelihood of tip-induced sample damage and inefficient AFM transduction.Here,individual liposomes loaded with the chemotherapeutic drug cytarabine are deposited intact from suspension via nano-electrospray gas-phase electrophoretic mobility molecular analysis (nES-GEMMA) collection and characterized at the nanoscale with the chemically-sensitive PTIR method.A new tapping-mode PTIR imaging paradigm based on heterodyne detection is shown to be better adapted to measure soft samples,yielding cytarabine distribution in individual liposomes and enabling classification of empty and drug-loaded liposomes.The measurements highlight PTIR capability to detect ~ 103 cytarabine molecules (~ 1.7 zmol) label-free and non-destructively.

关键词： tapping photothermal induced resonance (PTIR) nanoscale chemical imaging liposomes cytarabine drug delivery nanocarriers

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chemical Bond Calculations of Crystal Growth of KDP and ADP

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Journal of Rare Earths 2006年第Z1期24卷 144-148页

作者： Xu Dongli Xue Dongfeng State Key Laboratory of Fine chemicals Department of Materials Science and Chemical Engineering School of Chemical Engineering Dalian University of Technology Dalian 116012 China State Key Laboratory of Fine Chemicals Department of Materials Science and Chemical Engineering School of Chemical Engineering Dalian University of Technology Dalian 116012 China

A novel method was proposed to calculate the crystal morphology (or growth habit) on the basis of chemical bond analysis. All constituent chemical bonds were distinguished as relevant and independent bonds according to their variations during the crystallization process. By employing the current method, the influence of specific growth conditions on the crystal morphology can be considered in the structure analysis process. The ideal morphologies of both KDP (KH2PO4) and ADP (NH4H2PO4) crystals were calculated and compared with our obtained crystallites at room temperature, which validates the present calculation method very well.

关键词： chemical bond crystal morphology bond valence crystal surface crystal growth

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chemical looping combustion of coal in interconnected fluidized beds

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Science China(Technological Sciences) 2007年第2期50卷 230-240页

作者： SHEN LaiHong ZHENG Min XIAO Jun ZHANG Hui XIAO Rui Key Laboratory of Clean Coal Power Generation and Combustion Technology of Ministry of Education Southeast UniversityNanjing 210096China

chemical looping combustion is the indirect combustion by use of oxygen carrier. It can be used for CO2 capture in power generating processes. In this paper, chemical looping combustion of coal in interconnected fluidized beds with inherent separation of CO2 is proposed. It consists of a high velocity fluidized bed as an air reactor in which oxygen carrier is oxidized, a cyclone, and a bubbling fluidized bed as a fuel reactor in which oxygen carrier is reduced by direct and indirect reactions with coal. The air reactor is connected to the fuel reactor through the cyclone. To raise the high carbon conversion efficiency and separate oxygen carrier particle from ash, coal slurry instead of coal particle is introduced into the bottom of the bubbling fluidized bed. Coal gasification and the reduction of oxygen carrier with the water gas take place simultaneously in the fuel reactor. The flue gas from the fuel reactor is CO2 and water. Almost pure CO2 could be obtained after the con- densation of water. The reduced oxygen carrier is then returned back to the air reactor, where it is oxidized with air. Thermodyanmics analysis indicates that NiO/Ni oxygen carrier is the optimal one for chemical looping combustion of coal. Simulation of the processes for chemical looping combustion of coal, including coal gasification and reduction of oxygen carrier, is carried out with Aspen Plus software. The effects of air reactor temperature, fuel reactor temperature, and ratio of water to coal on the composition of fuel gas, recirculation of oxygen carrier par- ticles, etc., are discussed. Some useful results are achieved. The suitable tem- perature of air reactor should be between 1050―1150℃and the optimal temperature of the fuel reactor be between 900―950℃.

关键词： chemical looping combustion coal interconnected fluidized beds CO2 separation

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chemical Frequencymetry——Theory and Application

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Science China Chemistry 1993年第7期36卷 796-802页

作者：姚守拙谭胜连聂利华 New Material Research Institute Hunan University Changsha 410082 PRC

A new theory named 'chemical frequencymetry' is proposed. It is based on chemical reactions followed by piezoelectric monitoring. The frequency shift caused by the chemical reaction is related to the fundamental frequency (f) and overtone order (h) of the crystal, the formula weight (m) and diffusion coefficient (D) of the active chemical species, the diffusion layer thickness (δ), the response time(t), the concentration of the determinant (C_A) and the stoichiometric factor of the chemical reaction (k) according to the formulaThe technique has been applied to the determination of analgin as an example of its application.

关键词： chemical frequencymetry piezoelectric crystal microanalysis analgin sensor.

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Dynamic modifications of biomacromolecules: mechanism and chemical interventions

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Science China(Life Sciences) 2019年第11期62卷 1459-1471页

作者： Chu Wang Peng Zou Caiguang Yang Lei Liu Liang Cheng Xiaopeng He Liang Zhang Yan Zhang Hualiang Jiang Peng RChen College of Chemistry and Molecular Engineering Peking UniversityBeijing 100871China Shanghai Institute of Materia Medica Chinese Academy of SciencesShanghai 201203China Department of Chemistry Tsinghua UniversityBeijing 100084China Institute of Chemistry Chinese Academy of SciencesBeijing 100190China School of Chemistry and Molecular Engineering East China University of Science and TechnologyShanghai 200237China Department of Pharmacology and chemical Biology Shanghai Jiao Tong University School of MedicineShanghai 200025China National Natural Science Foundation of China Beijing 100085China

Biological macromolecules(proteins,nucleic acids,polysaccharides,etc.)are the building blocks of life,which constantly undergo chemical modifications that are often reversible and spatial-temporally regulated.These dynamic properties of chemical modifications play fundamental roles in physiological processes as well as pathological changes of living systems.The Major Research Project(MRP)funded by the National Natural Science Foundation of China(NSFC)—"Dynamic modifications of biomacromolecules:mechanism and chemical interventions"aims to integrate cross-disciplinary approaches at the interface of chemistry,life sciences,medicine,mathematics,material science and information science with the following goals:(i)developing specific labeling techniques and detection methods for dynamic chemical modifications of biomacromolecules,(ii)analyzing the molecular mechanisms and functional relationships of dynamic chemical modifications of biomacromolecules,and(iii)exploring biomacromolecules and small molecule probes as potential drug targets and lead compounds.

关键词： chemical biology biomacromolecule dynamic modification modification analysis chemical intervention

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Possible role of extracellular vesicles in exogenous chemical exposure-associated health concern

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Journal of Environmental Sciences 2019年第6期31卷 1-4页

作者： Guangbo Qu Xingchen Zhao Yanna Liu Fang Hao Jie Gao Lili Yang Qunfang Zhou Guibin Jiang State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences University of Chinese Academy of Sciences Institute of Environment and Health Jianghan University

Extracellular vesicles(EVs) are mediators of intercellular message communication by transferring lipids, proteins, genetic materials, and are therefore involved in a wide spectrum of physiological or pathological processes. Exogenous chemicals exposure may affect the function of EVs at the biogenesis, secretion, transport or reception stage, which could further result in abnormal information communication between cells, and thus induce toxicity and diseases. This review briefly explores the role of EVs in chemical exposure-associated health concern and progressive diseases.

关键词： EV Possible role of extracellular vesicles in exogenous chemical exposure-associated health concern

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A systematic strategy for screening therapeutic constituents of Schisandra chinensis(Turcz.) Baill infiltrated blood-brain barrier oriented in lesions using ethanol and water extracts:a novel perspective for exploring chemical material basis of herb medicines

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Acta Pharmaceutica Sinica B 2020年第3期10卷 557-568页

作者： Yiwen Zhang Xinyan Lv Jiameng Qu Xin Zhang Mingyang Zhang Hao Gao Qian Zhang Ran Liu Huarong Xu Qing Li Kaishun Bi School of Pharmacy Shenyang Pharmaceutical University Shenyang 110016China School of Traditional Chinese Materia Medica Shenyang Pharmaceutical UniversityShenyang 110016China

Schisandra chinensis,a widely used Chinese herbal medicine,was considered as central nervous system(CNS)drug for years.Both ethanol extracts(EES)and water extracts(WES)of it were applied clinically.Unfortunately,the difference of their efficacy and even effective material foundation of S.chinensis remains obscure.In this study,to explore the active constituents of S.chinensis,we compared pharmacodynamics and chemical profiles in vitrolin vivo of EES/WES for the first time using multiple chemical analysis,pharmacological and data processing approaches.It was proved that there was no significant difference in the anti-depressive effects between WES and EES.However,the contents of most components in vitro and in plasma were higher in EES than those in WES,which was unconvincing for their similar efficacy.Therefore,we further explored components of S.chinensis targeted onto brain and the results showed that 5 lignans were identified with definite absorptivity respectively both in EES and WES caused by the limitation of blood-brain barrier.Moreover,bioinformatic analysis predicted their anti-depressive action.Above all,the systematic strategy screened 5 brain-targeted effective substances of S.chinensis and it was suggested that exploring the components into nidi would promote the studies on herbs effective material basis.

关键词： Schisandra chinensis Ethanol extracts Water extracts Pharmacodynamics chemical profiles Components into nidi Effective material basis Traditional Chinese medicine

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