检索结果-南通市图书馆

Sub-micrometer-scale chemical analysis by nanosecond-laser-induced tip-enhanced ablation and ionization time-of-flight mass spectrometry

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2018年第11期11卷 5989-5996页

作者： Xiaoping Li Zhisen Liang Shudi Zhang Tongtong Wang Wei Hang Department of Chemistry and the MOE Key Lab ofSpectrochemicalAnalysis & Instrumentation College of Chemistry and ChemicalEngineering Xiamen University Xiamen 361005 China State Key Laboratory of Marine Environmental Science Xiamen University Xiamen 361005 China

The tip-enhanced near-field technique has drawn great attention recently because it is a promising technique for nanoscale chemical analysis when combined with other spectroscopic methods. Furthermore, this integration can improve the spatial resolution of mass spectrometry. In this study, a nanosecond-laser (ns-laser)-induced tip-enhanced ablation and ionization source was coupled to an in-house-built laser ionization time-of-flight mass spectrometer. Sub-micrometer-sized craters (with diameters of 200–300 nm) were observed on titanium (Ti) film coated onto a gold (Au) substrate. The corresponding mass spectra were acquired, which verified that sub-micrometer-sized ablation (and subsequently ionization) could be achieved by the ns-laser-induced tip-enhanced electromagnetic field. In addition, formation of the crater was studied with an increased number of laser pulses. Furthermore, a mass spectrometry imaging (MSI) experiment was performed with potassium chloride (KCl) residue dropped onto nano-patterned gold pillars, achieving 80-nm lateral resolution.

关键词： tip-enhanced near-field technique time-of-flight mass spectrometer nanosecond laser sub-micrometer-scale spatial resolution

mass Spectrometric Studies on Metal-hexafluorobenzene Anionic Complexes(M=Ag, Au, Pd, Pt, Pb and Bi)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2009年第2期25卷 228-233页

作者： SUN Zhang SUN Shu-tao LIU Hong-tao ZHU Qi-he GAO Zhen TANG Zi-chao Beijing National Laboratory for Molecular Sciences（BNLMS） State Key Laboratory of Molecular Reaction Dynamics Center of Molecular Science Institute of Chemistry Chinese Academy of Sciences Beo＇ing 100080 P. R. China State Key Laboratory of Molecular Reaction Dynamics Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 P R. China

The anionic products from the reactions between metal（M=Ag, Au, Pd, Pt, Pb and Bi） vapour produced by laser ablation and hexafluorobenzene seeded in carrier gas（Ar） were studied by means of a homemade reflectron time-of-flight mass spectrometry（RTOF-MS）. Experimental results show that the dominant products were [MmC6F6]^- complexes for the reactions ofAg, Au, Pd and Pt with C6F6, while the dominant products were [MmC6F5]^- complexes for the reactions of Pb and Bi with C6F6. The formation mechanisms of the products, including the adsorption of metal cluster anions on hexafluorobenzene and the C--F cleavage induced by metal cluster anions, were discussed.

关键词： time-of-flight mass spectrometer Metal cluster Anionic complex Reaction mechanism

Experimental and Theoretical Study of Hydrogen Atom Abstraction from Ethylene by Stoichiometric Zirconium Oxide Clusters

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Physics 2009年第6期22卷 635-641,J0002页

作者： Xiao-nan Wu Yan-xia Zhao Sheng-gui He Xun-lei Ding Beijing National Laboratory for Molecular Sciences State Key Laboratory for Structural Chemistry of Unstable and Stable Species Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China Graduate University of the Chinese Academy of Sciences Beijing 200049 China

The reactions of cationic zirconium oxide clusters （ZrxOy^＋） with ethylene （C2H4） were investigated by using a time-of-flight mass spectrometer coupled with a laser ablation/supersonic expansion cluster source. Some hydrogen containing products （ZrO2）xH^＋（x=-1-4） were observed after the reaction. The density functional theory calculations indicate that apart from the common oxygen transfer reaction channel, the hydrogen abstraction channel can also occur in （ZrO2）x^＋＋C2H4, which supports that the observed （ZrO2）xH^＋ may be due to （ZrO2）x^＋＋C2H4→（ZrO2）xH^＋＋C2H3. The rate constants of different reaction channels were also calculated by Rice-Rarnsberger-Kassel-Marcus theory.

关键词： time-of-flight mass spectrometer Zirconium oxide clusters Fast flow reactor Density functional theory Rice-Ramsberger-Kassel-Marcus theory

Optimization of multi-reflection time-of-flight mass analyzer operating in in-trap-lift mode

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Radiation Detection Technology and Methods 2018年第1期2卷 1-6页

作者： Wen-Xue Huang Yu-Lin Tian Yong-Sheng Wang Jun-Ying Wang Xiao-Hong Zhou Institute of Modern Physics Chinese Academy of SciencesLanzhou730000China School of Physical Sciences University of Chinese Academy of SciencesBeijing100049China School of Nuclear Science and Technology Lanzhou UniversityLanzhou730000China

Purpose We are building an MRTOF-MS(multi-reflection time-of-flight mass spectrometer)for isobaric separation for the Lanzhou Penning *** potentials applied on the electrodes of our MRTOF mass analyzer operating in in-trap-lift mode have to be optimized to achieve a very high mass resolving *** Our method to design and optimize an MRTOF mass analyzer has been updated to introduce constraints on the potentials,and this method now can be used to optimize the parameters of MRTOF-MS both operating in mirror-switching mode and in in-trap-lift *** using this method,the optimal potential parameters of the electrodes have been obtained for our MRTOF mass analyzer operating in the in-trap-lift *** and conclusion With a beam size of 2.8 mm diameter and an initial average ion kinetic energy of 1500 eV,the maximal mass resolving power has been achieved to be 3.2×10^(4) with a total TOF of 7.0 ms for an ion species of ^(40)Ar^(1+).It can reach up to 5.6×10^(4) for a beam size of 0.3 mm *** simulation shows that the inaccuracy of the potentials applied on the outermost mirror electrodes M1–M2 must be less than 50 ppm or preferably 20 ppm.

关键词： time-of-flight mass spectrometer Multiple reflection mass measurement Isobaric separation Exotic nuclei

Development of High-Resolution time-of-flight mass Spectrometry–Theoretical and Experimental Study

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Development of High-Resolution Time-of-Flight Mass Spectrome...