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Theoretical analysis of chemical bonding behaviors and dielectric properties of different phases of ice

100%

Xue D. , Betzler K. , Hesse H. , Ratajczak H.

Bulletin of the Polish Academy of Sciences. Chemistry

2001

tom Vol. 49, No. 4

289-298

From the chemical bond viewpoint, the chemical bond parameters, linear optical properties and geometrical characteristics of constituent chemical bonds (i.e., O-H and H.. .O bonds) in the single-crystalline ice phases I, II, III, VI, VII and VIII have been quantitatively studied. At the same time, the chemical bonding situations of constituent H(D) atoms in different phases of ice have been numerically scaled. The calculated results show that the different lengths and directions of the hydrogen bonding O-H(D).. .O (including two parts: H(D)-O and H(D).. .O bonds) in the different phases of ice cause a large variation in the linear optical properties. Their characteristics found in single-crystalline phases of ice can be used as a guideline for the application of this special kind of functional chemical bond as linkage in materials design.

N-acetylcysteine (NAC) attenuating apoptosis and autophagy in RAW264.7 cells in response to incubation with mycolic acid from bovine Mycobacterium tuberculosis complex

88%

Lin X. , Wei M. , Song F. , Xue D. , Wang Y.

tom 69

nr 2

Remote Sensing Monitoring of Volcanic Ash Clouds Based on PCA Method

75%

Li C. , Dai Y. , Zhao J. , Zhou S. , Yin J. , Xue D.

Acta Geophysica

2015

tom Vol. 63, no. 2

432--450

Volcanic ash clouds threaten the aviation safety and cause global environmental effects. It is possible to effectively monitor the volcanic ash cloud with the aid of thermal infrared remote sensing technology. Principal component analysis (PCA) is able to remove the inter-band correlation and eliminate the data redundancy of remote sensing data. Taking the Eyjafjallajokull volcanic ash clouds formed on 15 and 19 April 2010 as an example, in this paper, the PCA method is used to monitor the volcanic ash cloud based on MODIS bands selection; the USGS standard spectral database and the volcanic absorbing aerosol index (AAI) are applied as contrasts to the monitoring result. The results indicate that: the PCA method is much simpler; its spectral matching rates reach 74.65 and 76.35%, respectively; and the PCA method has higher consistency with volcanic AAI distribution.

Vibrational Spectra, Phase Transition and Nonlinear Optical Properties of Anilinium Perchlorate Molecular-Ionic Solid

75%

Marchewka M. , Debrus S. , Drozd M. , Baran J. , Barnes A. J. , Xue D. , Ratajczak H.

2003

tom Vol. 77 / nr 11

1625-1636

Crystals of anilinium perchlorate, C6H5NH ClO 3 4 + , were obtained by slow evaporation of an aqueous solution at room temperature. Powder Kurtz-Perry measurements were performed for the title material. The efficiency of second harmonic generation was estimated relative to KDP: d = 0.21dKDP. Room temperature powder infrared and Raman measurements for the title solid and its deuterated analogue were carried out. The vibrational spectra in the regions of the internal vibrations of the ions corroborate the X-ray data (reported by Paixao et al. [1]). Differential scanning measurements performed on the powder sample indicate a first order phase transition at about 220 K.Apossible mechanism of the phase transition is suggested in relation to disorder of the hydrogen atoms on nitrogen atoms (reported in [1]). The role of the aniline molecule in the second harmonic generation is discussed.

Culturable endophytes diversity isolated from Paeonia ostii and the genetic basis for their bioactivity

75%

Yang R.-H. , Zhang S.-W. , Xue D. , Xuan J.-H. , Zhang Y.-B. , Peng B.-B.

Polish Journal of Microbiology

2018

tom 67

nr 4

Paeonia ostii is known for its excellent medicinal values as Chinese traditional plant. To date, the diversity of culturable endophytes associated with P. ostii is in its initial phase of exploration. In this study, 56 endophytic bacteria and 51 endophytic fungi were isolated from P. ostii roots in China. Subsequent characterization of 56 bacterial strains by 16S rDNA gene sequence analysis revealed that nine families and 13 different genera were represented. All the fungal strains were classed into six families and 12 genera based on ITS gene sequence. The biosynthetic potential of all the endophytes was further investigated by the detection of putative polyketide synthase (PKS) and nonribosomal peptide synthetase (NRPS) genes. The PCR screens were successful in targeting thirteen bacterial PKS, five bacterial NRPS, ten fungal PKS and nine fungal NRPS gene fragments. Bioinformatic analysis of these detected endophyte gene fragments facilitated inference of the potential bioactivity of endophyte bioactive products, suggesting that the isolated endophytes are capable of producing a plethora of secondary metabolites. These results suggest that endophytes isolated from P. ostii had abundant population diversity and biosynthetic potential, which further proved that endophytes are valuable reservoirs of novel bioactive compounds.