A systematic study on geometry, electronic structure and vibrational properties of N-doped TiO2 anatase cluster, within the framework of the density functional theory, has been performed in this work. The calculations...A systematic study on geometry, electronic structure and vibrational properties of N-doped TiO2 anatase cluster, within the framework of the density functional theory, has been performed in this work. The calculations confirmed that the most structures in substitutional model consist of a two-coordinate bridge structure and a three-coordinate hollow structure. The calculated results can well explain the red shift in N-doped TiO2 observed in experiments. The study provides an illustration for the N-doped anatase from the viewpoint of chemical bonding theory.展开更多
The reactions of anionic zirconium oxide clusters ZrxOy- with C2H6 and C4H10 are investi-gated by a time of flight mass spectrometer coupled with a laser vaporization cluster source.Hydrogen containing products Zr2O5H...The reactions of anionic zirconium oxide clusters ZrxOy- with C2H6 and C4H10 are investi-gated by a time of flight mass spectrometer coupled with a laser vaporization cluster source.Hydrogen containing products Zr2O5H- and Zr3O7H- are observed after the reaction. Den-sity functional theory calculations indicate that the hydrogen abstraction is favorable in the reaction of Zr2O5- with C2H6, which supports that the observed Zr2O5H- and Zr3O7H- are due to hydrogen atom abstraction from the alkane molecules. This work shows a newpossible pathway in the reaction of zirconium oxide cluster anions with alkane molecules.展开更多
The structure and magnetic properties of Osn (n=11~22) clusters are systematically studied by using density functional theory (DFT). For each size, the average binding energy per atom, the second-order difference...The structure and magnetic properties of Osn (n=11~22) clusters are systematically studied by using density functional theory (DFT). For each size, the average binding energy per atom, the second-order differences of total energies and the highest occupied molecular orbital (HOMO)–the lowest unoccupied molecular orbital (LUMO) gaps are calculated to analyze the stability of the cluster. The structures of Os14 and Os18 clusters are based on a close-packed hexagonal structure, and they have maximum stabilities, so n=14, 18 are the magic numbers. The 5d electrons play a dominant role in the chemical reaction of Osn clusters. The magnetic moments of Osn clusters are quenched around n=12, and when n=18~22 the value approximates to zero, due to the difference of electron transfer.展开更多
Classification systems such as Slope Mass Rating(SMR) are currently being used to undertake slope stability analysis. In SMR classification system, data is allocated to certain classes based on linguistic and experien...Classification systems such as Slope Mass Rating(SMR) are currently being used to undertake slope stability analysis. In SMR classification system, data is allocated to certain classes based on linguistic and experience-based criteria. In order to eliminate linguistic criteria resulted from experience-based judgments and account for uncertainties in determining class boundaries developed by SMR system,the system classification results were corrected using two clustering algorithms, namely K-means and fuzzy c-means(FCM), for the ratings obtained via continuous and discrete functions. By applying clustering algorithms in SMR classification system, no in-advance experience-based judgment was made on the number of extracted classes in this system, and it was only after all steps of the clustering algorithms were accomplished that new classification scheme was proposed for SMR system under different failure modes based on the ratings obtained via continuous and discrete functions. The results of this study showed that, engineers can achieve more reliable and objective evaluations over slope stability by using SMR system based on the ratings calculated via continuous and discrete functions.展开更多
As a continuation of a series of work, we aim to refine and re-determine the physical parameters of previously rarely or un-studied open star clusters with good quality CMDs using Near-IR JHK photometry. Here we prese...As a continuation of a series of work, we aim to refine and re-determine the physical parameters of previously rarely or un-studied open star clusters with good quality CMDs using Near-IR JHK photometry. Here we present a morphological analysis of the 2MASS database (the digital "Two Micron All Sky Survey") for the open cluster Pismis 3. Some of the physical parameters are estimated for the first time, and some others, re-determined.展开更多
Activating transcription factor 2(ATF2)is a member of the ATF/cyclic AMP-responsive element bind-ing protein family of transcription factors.However,the information concerning ATF2 ion-mediated DNA binding module and ...Activating transcription factor 2(ATF2)is a member of the ATF/cyclic AMP-responsive element bind-ing protein family of transcription factors.However,the information concerning ATF2 ion-mediated DNA binding module and function of ATF2 in malignant pleural mesothelioma(MPM)has never been addressed.In this study,by using GRNInfer and GVedit based on linear pro-gramming and a decomposition procedure,with integrated analysis of the function cluster using Kappa statistics and fuzzy heuristic clustering in MPM,we identified one ATF2 ion-mediated DNA binding module involved in invasive function including ATF2 inhibition to target genes FALZ,C20orf31,NME2,PLOD2,RNF10,and RNASEH1,upstream RNF10 and PLOD2 activation to ATF2,upstream RNASEH1 and FALZ inhibition to ATF2 from 40 MPM tumors and 5 normal pleural tissues.Remarkably,our results showed that the predominant effect of ATF2 occupancy is to suppress the activation of target genes on MPM.Importantly,the ATF2 ion-mediated DNA binding module reflects‘mutual’positive and negative feedback regulation mechanism of ATF2 with up-and down-stream genes.It may be useful for developing novel prognostic markers and therapeutic targets in MPM.展开更多
基金Supported by the National Natural Science Foundation of China (No. 20503021)National Basic Research Program of China (2007CB815301)
文摘A systematic study on geometry, electronic structure and vibrational properties of N-doped TiO2 anatase cluster, within the framework of the density functional theory, has been performed in this work. The calculations confirmed that the most structures in substitutional model consist of a two-coordinate bridge structure and a three-coordinate hollow structure. The calculated results can well explain the red shift in N-doped TiO2 observed in experiments. The study provides an illustration for the N-doped anatase from the viewpoint of chemical bonding theory.
基金This work was supported by the Chinese Academy of Sciences (Hundred Talents Fund), the National Natural Science Foundation of China (No.20703048 and No.20803083), and the Center of Molecular Science Foundation of Institute of Chemistry, Chinese Academy of Sciences (No.CMS-LX200902).
文摘The reactions of anionic zirconium oxide clusters ZrxOy- with C2H6 and C4H10 are investi-gated by a time of flight mass spectrometer coupled with a laser vaporization cluster source.Hydrogen containing products Zr2O5H- and Zr3O7H- are observed after the reaction. Den-sity functional theory calculations indicate that the hydrogen abstraction is favorable in the reaction of Zr2O5- with C2H6, which supports that the observed Zr2O5H- and Zr3O7H- are due to hydrogen atom abstraction from the alkane molecules. This work shows a newpossible pathway in the reaction of zirconium oxide cluster anions with alkane molecules.
基金Project supported by the National Natural Science Foundation of China(Grant No.51072072)
文摘The structure and magnetic properties of Osn (n=11~22) clusters are systematically studied by using density functional theory (DFT). For each size, the average binding energy per atom, the second-order differences of total energies and the highest occupied molecular orbital (HOMO)–the lowest unoccupied molecular orbital (LUMO) gaps are calculated to analyze the stability of the cluster. The structures of Os14 and Os18 clusters are based on a close-packed hexagonal structure, and they have maximum stabilities, so n=14, 18 are the magic numbers. The 5d electrons play a dominant role in the chemical reaction of Osn clusters. The magnetic moments of Osn clusters are quenched around n=12, and when n=18~22 the value approximates to zero, due to the difference of electron transfer.
文摘Classification systems such as Slope Mass Rating(SMR) are currently being used to undertake slope stability analysis. In SMR classification system, data is allocated to certain classes based on linguistic and experience-based criteria. In order to eliminate linguistic criteria resulted from experience-based judgments and account for uncertainties in determining class boundaries developed by SMR system,the system classification results were corrected using two clustering algorithms, namely K-means and fuzzy c-means(FCM), for the ratings obtained via continuous and discrete functions. By applying clustering algorithms in SMR classification system, no in-advance experience-based judgment was made on the number of extracted classes in this system, and it was only after all steps of the clustering algorithms were accomplished that new classification scheme was proposed for SMR system under different failure modes based on the ratings obtained via continuous and discrete functions. The results of this study showed that, engineers can achieve more reliable and objective evaluations over slope stability by using SMR system based on the ratings calculated via continuous and discrete functions.
基金This paper has made use of the Two Micron All Sky Survey (2MASS), which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation. Catalogues from CDS/SIMBAD (Strasbourg) and Digitized Sky Survey DSS images managed by the Space Telescope Science Institute have been employed.
文摘As a continuation of a series of work, we aim to refine and re-determine the physical parameters of previously rarely or un-studied open star clusters with good quality CMDs using Near-IR JHK photometry. Here we present a morphological analysis of the 2MASS database (the digital "Two Micron All Sky Survey") for the open cluster Pismis 3. Some of the physical parameters are estimated for the first time, and some others, re-determined.
基金supported by the National Natural Science Foundation of China(Grant No.60673109)the Teaching and Scientific Research Foundation for the Returned Overseas Chinese Scholars,Ministry of Education of China.
文摘Activating transcription factor 2(ATF2)is a member of the ATF/cyclic AMP-responsive element bind-ing protein family of transcription factors.However,the information concerning ATF2 ion-mediated DNA binding module and function of ATF2 in malignant pleural mesothelioma(MPM)has never been addressed.In this study,by using GRNInfer and GVedit based on linear pro-gramming and a decomposition procedure,with integrated analysis of the function cluster using Kappa statistics and fuzzy heuristic clustering in MPM,we identified one ATF2 ion-mediated DNA binding module involved in invasive function including ATF2 inhibition to target genes FALZ,C20orf31,NME2,PLOD2,RNF10,and RNASEH1,upstream RNF10 and PLOD2 activation to ATF2,upstream RNASEH1 and FALZ inhibition to ATF2 from 40 MPM tumors and 5 normal pleural tissues.Remarkably,our results showed that the predominant effect of ATF2 occupancy is to suppress the activation of target genes on MPM.Importantly,the ATF2 ion-mediated DNA binding module reflects‘mutual’positive and negative feedback regulation mechanism of ATF2 with up-and down-stream genes.It may be useful for developing novel prognostic markers and therapeutic targets in MPM.