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Observation of chemical components of PM2.5 and secondary inorganic aerosol formation during haze and sandy haze days in Zhengzhou, China

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Journal of Environmental Sciences 2020年第2期32卷 316-325页

作者： Zhangsen Dong Fangcheng Su Zhenya Zhang Shenbo Wang Graduate School of Life and Environmental Sciences University of TsukubaJapan Research Institute of Environmental Science College of Chemistry and Molecular EngineeringZhengzhou UniversityZhengzhou 450001China

Mineral dust particles play an important role in the formation of secondary inorganic aerosols, which largely contribute to haze pollution in China.During this study, a haze episode(haze days) and a typical haze process mixed with sandstorm(sandy haze days)were observed in Zhengzhou with a series of high-time-resolution monitoring instruments from November 22 to December 8, 2018.Concentrations of PM10 and crustal elements clearly increased in the sandy haze days.Concentrations of gaseous pollutants, metallic elements emitted from anthropogenic sources, nitrate, and ammonium during sandy haze days were slightly lower than those during the haze days but still obviously higher than those during the non-haze days.The sulfate concentrations, the sulfate fractions in PM2.5,and the sulfur oxidation ratios significantly increased in the sandy haze days.Heterogeneous reactions dominated the conversion of SO2 during the haze and sandy haze days.Enhanced SO2 conversion during the sandy haze days may be attributed to the high concentrations of transition metal ions from the sandstorm when the values of relative humidity(RH) were in 30%–70%, and high O3 at certain time points.Gas-phase NO2 oxidation reactions were the main pathways for nitrate formation.In the sandy haze days,higher nitrogen oxidation ratio(NOR) at daytime may be associated with higher RH and lower temperature than those in the haze days, which facilitate the gas-to-particle partitioning of nitrate;higher NOR values at night may be attributed to the higher O3 concentrations, which promoted the formation of N2O5.

关键词： Sandstorm Haze Sulfate Aqueous-phase reactions Transition metal ions

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1-2 Nuclear Fragmentation in Low-energy Antiproton Induced reactions

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IMP & HIRFL Annual Report 2015年第1期 4-5页

作者： Feng Zhaoqing 不详

The dynamics of antiproton-nucleus collisions is complicated, which is associated with the mean-field potentials of hadrons in nuclear medium, and also with a number of reaction channels, i.e., the annihilation channels, chargeexchange reaction, elastic and inelastic collisions. Larger yields of strange particles in antiproton induced reactions are favorable to form hypernuclei in comparison to proton-nucleus and heavy-ion collisions.

关键词： Nuclear Low-energy reactions

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Synergistic effects of Mg-substitution and particle size of chicken eggshells on hydrothermal synthesis of biphasic calcium phosphate nanocrystals

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Journal of Materials Science & Technology 2020年第1期36卷 27-36页

作者： Wei Cui Qibin Song Huhu Su Zhiqing Yang Rui Yang Na Li Xing Zhang Institute of Metal Research Chinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaHefei 230026China Department of Plastic Surgery Shengjing Hospital of China Medical UniversityShenyang 110004China

Magnesium(Mg^2+))ion plays important roles in biomineralization of bone,teeth and calcium carbonate skeletons.Herein,chicken eggshells mainly comprising of Mg-calcite nanocrystals(Mg/(Mg+Ca)2.0 mol.%)were used to fabricate biphasic calcium phosphate(BCP),a mixture of hydroxyapatite(HA)and p-tricalcium phosphate(p-TCP)nanocrystals,through hydrothermal reactions at 200℃for 24 h.Our results indicated thatβ-TCP nanocrystals formed through the ion-exchange reactions of Mg-calcite,while HA nanocrystals were mainly produced by dissolution-reprecipitation reactions on the surfaces of eggshell samples in the hydrothermal system.Mg substitution in calcite resulted in formation ofβ-TCP nanocrystals instead of HA crystals through ion-exchange reactions.BCP samples with different compositions(28.6-77.8 wt.%β-TCP)were produced by controlling particle sizes of eggshells for hydrothermal reactions.The larger particles lead to the larger proportion ofβ-TCP in the BCP composition.Therefore,Mg substitution and particle size had synergetic effects on the hydrothermal synthesis of BCP using chicken eggshells through balance of ion-exchange and dissolution-reprecipitation reactions.Cell culture results showed that the BCP products were non-cytotoxic to MC3 T3-E1 cells,which may be used for bone substitute materials in future.

关键词： Hydrothermal reactions Ion-exchange Dissolution-reprecipitation Nanocrystals Biphasic calcium phosphate Bone substitute materials

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Fluorine-containing oxidizers for metal fuels in energetic formulations

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Defence Technology（防务技术） 2019年第1期15卷 1-22页

作者： Siva Kumar Valluri Mirko Schoenitz Edward Dreizin New Jersey Institute of Technology Tomsk State University

Fluorine containing oxidizers, primarily polymers, are extensively used in pyrotechnic compositions.Fluorinated oxidizers are less explored for metalized propellants and explosives despite a potential advantage of substantial heat release combined with gaseous combustion products. This review summarizes different types of fluorinated oxidizers used in energetic formulations or of potential interest for such systems, including gases, polymers, and inorganic compounds. Types of energetic formulations employing metals and fluoropolymers are discussed in more detail, including methods used to prepare composites and resulting salient features of the obtained materials. Laboratory experiments characterizing such materials, in particular, electron microscopy and thermal analysis, are discussed, showing characteristic morphologies and reaction sequences observed in different metal-fluorinated oxidizer composites. Striking similarities are noted in reaction sequences for diverse compositions hinting at possible similarities in the respective reaction mechanisms. Experiments probing ignition and combustion of metal-fluorinated oxidizer composites in laboratory conditions are also reviewed, including impact, flash heating and shock ignition. Finally, some practical performance tests for energetic formulations are described following by a brief discussion of the reaction mechanisms expected to govern ignition and combustion in various metal-fluorinated oxidizer composites. The conclusions are combined with recommendation for future research in the area of reactive metal-fluorinated oxidizer composites.

关键词： Reactive materials Composites Redox reactions Pyrotechnics Propellants Explosives

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Coronary CT Angiography Using Low Iodine Delivery Rate and Tube Voltage Determined by Body Mass Index:Superiority in Clinical Practice

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Current Medical Science 2019年第5期39卷 825-830页

作者： Wang YUAN Ting-ting QU Hui-juan WANG Mei-yu WANG Yuan QU Gang NIU Jian YANG Department of Diagnostic Radiology the First Hospital of Medical Science CentreXi'an Jiaotong UniversityXi'an 710061China Department of Dermatology the Ninth Hospital of Xi'anXi'an 710054China

To explore the feasibility and superiority of iodine delivery rate(IDR)and tube voltage determined by patients'body mass index(BMI)in coronary CT angiography(CCTA),a total of 1567 patients undertaking CCTA during Feb.and Dec.2016 were enrolled and divided into two groups.In the control group,the IDR and tube voltage were fixed,while in the experimental group,the IDR and tube voltage were determined by patients,BMI.The volume of iodinated contrast media(ICM),extravasation rate,extravasation volume,extravasation recovery interval,incidence rate of adverse reactions,effective dose(ED)and image quality of the two groups were compared.The experiments demonstrated that the ICM volume,extravasation rate,extravasation volume,extravasation recovery interval,incidence of adverse reactions and ED were lower or shorter in the experimental group than in the control group,and the differences were statistically significant(all P<0.05).However,there were no significant differences in the mean CT value,image noise,signal to noise ratio and contrast to noise ratio between the two groups(all P<0.05),which were consistent with the diagnosticians*subjective evaluation outcomes.Our findings suggested that in CCTA,it is feasible to determine the IDR and tube voltage based on patients'BMI;low tube voltage and IDR are superior to the fixed tube voltage and IDR and are worthy of clinical promotion.

关键词： iodinated contrast media iodine delivery rate tube voltage ICM extravasation adverse reactions

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Trifluoromethyl radical triggered radical cyclization of N-benzoyl ynamides leading to isoindolinones

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Science China Chemistry 2019年第11期62卷 1542-1546页

作者： Maud Cassé Christian Nisole Héloise Dossmann Yves Gimbert Jean-Marie Fourquez Laure Haberkorn Cyril Ollivier Louis Fensterbank Sorbonne Université CNRSInstitut Parisien de Chimie MoléculaireIPCM75005 ParisFrance Institut de Recherches Servier 78290 Croissy-sur-SeineFrance Département de Chimie Moléculaire CNRSUniversitéGrenoble Alpes38610 GièresFrance

Under photocatalytic reductive conditions,trifluoromethyl radical addition onto an ynamide followed by cyclization on a benzoyl moiety produces diverse isoindolinone platforms with good yields.The selectivity of the radical cyclization,N-benzoyl vs.N-benzyl as radical acceptor and the E/Z ratio of isomers have been rationalized by modeling.

关键词： ynamides trifluoromethylation photocatalysis cascade reactions tandem processes isoindolinones modeling

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Chapter model systems in heterogeneous catalysis at the atomic level: a personal view

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Science China Chemistry 2020年第4期63卷 426-447页

作者： Hans-Joachim Freund Markus Heyde Helmut Kuhlenbeck Niklas Nilius Thomas Risse Thomas Schmidt Shamil Shaikhutdinov Martin Sterrer Fritz Haber Institute of the Max Planck Society Faradayweg 4-6Berlin D-14195Germany Fakultat V-Mathematik und Naturwissenschaften Carl von Ossietzky Universitat OldenburgGermany Institut fur Chemie und Biochemie Freie UniversitatBerlinGermany Institute of Physics University of GrazGrazAustria

The review presents an overview of studies in the surface science of oxide and related surfaces with an emphasis of the studies performed in the authors’ group. Novel instruments and technique developments, as well as their applications are reported, in an attempt to cover studies on model systems of increasing complexity, including some of the key ingredients of an industrially applied heterogeneous catalyst and its fabrication. The review is intended to demonstrate the power of model studies in understanding heterogeneous catalysis at the atomic level. The studies include those on supported nano-particles, both, prepared in vacuum and from solution, interaction of surfaces and the underlying bulk with molecules from the gas phase, strong metal support interaction, as well as the first attempt to include studies on reactions in confined spaces.

关键词： model catalysts oxide surfaces structure and spectroscopy supported nanoparticles reactions in the confined space

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Electrochemical Oxidative Csp^3—H/S—H Cross-Coupling with Hydrogen Evolution for Synthesis of Tetrasubstituted Olefins

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Chinese Journal of Chemistry 2019年第6期37卷 547-551,I0002页

作者： Fangling Lu Zengzhuan Yang Tao Wang Tianhao Wang Yuying Zhang Yong Yuan Aiwen Lei National Research Center for Carbohydrate Synthesis Jiangxi Province's Key Laboratory of Chemical BiologyJiangxi Normal UniversityNanchangJiangxi 330022China College of Chemistry and Chemical Engineering Jiangxi Normal UniversityNanchangJiangxi 330022China College of Chemistry and Molecular Sciences the Institute for Advanced Studies (IAS)Wuhan UniversityWuhanHubei 430072China

Tetrasubstituted olefins are significant scaffolds as they are prevalent in many biologically active compounds and versatile building blocks for organic synthesis. Herein, we report an electrochemical oxidative Csp^3—H/S—H cross-coupling reaction, in which various tetrasubstituted olefins were prepared under base-free, transition metal-free, and oxidants-free reaction conditions.

关键词： electrochemistry C-H activation cross-coupling radical reactions synthetic methods

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Two Zinc Complexes Supported by in situ Formed Etheric Ligands

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Chinese Journal of Structural Chemistry 2019年第9期38卷 1593-1599页

作者：杨乐刘勇路张恩生陈小莉高楼军杨华 Laboratory of New Energy&New Function Materials Shaanxi Key Laboratory of Chemical Reaction EngineeringCollege of Chemistry and Chemical EngineeringYan’an UniversityShaanxi716000China College of Chemistry and Chemical Engineering Xi’an University of Science and TechnologyXi’an710054China College of Chemistry Chemical Engineering and Materials ScienceSoochow UniversitySuzhou215123China

Two zinc complexes, [Zn(MPIP)Cl2](1) and [Zn(EPIP)Cl2](2), where MPIP = 1-(methoxymethyl)-3-(pyridin-2-yl)imidazo[1,5-a]pyridine and EPIP = 1-(ethoxymethyl)-3-(pyridin-2-yl)imidazo[1,5-a]pyridine, were synthesized under solvothermal conditions. The etheric ligand MPIP was formed in situ via metal ligand reaction between(3-(pyridin-2-yl)imidazo[1,5-a]pyridin-1-yl)methanol(HPIPM) and methanol solvent. Similarly, the ligand EPIP was generated in situ from the reaction of HPIPM with ethanol solvent. The structures of 1 and 2 were characterized by X-ray single-crystal diffraction analysis. They are four-coordinated mononuclear complexes, and the ZnII ion of 1 and 2 displays distorted tetrahedral geometry. The photoluminescent properties of 1 and 2 were investigated. Strong emissions were observed for both 1 and 2, which were ascribed as the intraligand(π-π*) fluorescent transitions. This paper provides a simple and efficient method for the synthesis of etheric compounds.

关键词： zinc complexes in situ reactions etheric ligands photoluminescent property

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The xanthate route to all-carbon quaternary centers

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Science China Chemistry 2019年第11期62卷 1450-1462页

作者： Béatrice Quiclet-Sire Samir Z.Zard Laboratoire de Synthèse Organique Ecole Polytechnique

This review discusses the numerous routes to all-carbon quaternary centers based on the unique radical chemistry of xanthates. Itsummarizes the various approaches to the synthesis of tertiary xanthates then describes the intra- and intermolecular radicaladditions and combinations thereof that have so far been used to construct quaternary centers.

关键词： xanthates quaternary centers radical addition cyclization tandem reactions

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