oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 262 )

2018 ( 2704 )

2017 ( 2608 )

2016 ( 2588 )

Custom range...

Search Results: 1 - 10 of 172001 matches for " LI Jun-Feng "
All listed articles are free for downloading (OA Articles)
Page 1 /172001
Display every page Item
Influence Factors on the Porosity and Strength of SiC Porous Ceramic
LI Jun-Feng, LIN Hong, LI Jian-Bao
无机材料学报 , 2011, DOI: 10.3724/sp.j.1077.2011.00944
Abstract: The influence of ceramic binder contents, SiC particle sizes, and sintering temperatures on the porosity and flexural strength of SiC porous ceramics for high―temperature gas filtration were investigated. The composition of SiC porous ceramics was measured by X―ray diffraction. The porosity of SiC porous ceramics decreased with increasing the ceramic binder contents, and the SiC porous ceramic with a relatively high porosity of 37.5% and flexural strength of 27.63MPa was obtained with ceramic binder content of 15wt%. Both the porosity and flexural strength of SiC porous ceramics increased with SiC particle sizes decreasing from 300um to 87um, and the porosity increased from 35.5% to 42.4%, while the flexural strength increased from 19.92MPa to 25.18MPa. In addition, the porosity of SiC porous ceramics quickly decreased from 38.7% to 35.4% with sintering temperatures increasing from 1300 to 1400 , but the flexural strength of SiC porous ceramics had only a slight change, mainly standing at about 27MPa. Thus, the sintering temperature of SiC porous ceramics should be selected around the melting point of ceramic binder (1300 ).
6,6′-Diethoxy-2,2′-[propane-1,3-diyldioxybis(nitrilomethylidyne)]diphenol
Li Wang,Yin-Xia Sun,Jun-Feng Tong
Acta Crystallographica Section E , 2010, DOI: 10.1107/s1600536810003430
Abstract: The complete molecule of the title compound, C21H26N2O6, is generated by a crystallographic twofold axis and adopts a trans configuration with respect to the azomethine group. The two benzene rings are almost perpendicular to one another, making a dihedral angle of 89.53 (3)°. In the molecular structure, pairs of intramolecular O—H...N hydrogen bonds generate two six-membered rings. The crystal structure is further stabilized by intermolecular C—H...O hydrogen bonds, which link four adjacent molecules into a network structure.
4,4′-Di-3-pyridyl-2,2′-dithiodipyrimidine
Jun-Feng Ji,Lei Li,Hai-Bin Zhu
Acta Crystallographica Section E , 2009, DOI: 10.1107/s1600536809016869
Abstract: The asymmetric unit of the title compound, C18H12N6S2, contains one half-molecule situated on a twofold rotational axis that passes through the mid-point of the S—S bond. In the molecule, the C—S—S—C torsion angle is 81.33 (7)°. The crystal packing exhibits no significantly short intermolecular contacts.
{Bis[4-(2-pyridyl)pyrimidin-2-yl]sulfane}dichloridocobalt(II)
Hai-Bin Zhu,Lei Li,Jun-Feng Ji
Acta Crystallographica Section E , 2009, DOI: 10.1107/s1600536809022636
Abstract: The asymmetric unit of the title compound, [CoCl2(C18H12N6S)], contains one half-molecule situated on a twofold rotation axis which passes through the Co and S atoms. The metal centre is in a distorted octahedral CoCl2N4 coordination with the Cl atoms in the axial positions. In the crystal structure, intermolecular C—H...Cl interactions help to establish the packing.
Construction and Evaluation of Normalized cDNA Libraries Enriched with Full-Length Sequences for Rapid Discovery of New Genes from Sisal (Agave sisalana Perr.) Different Developmental Stages
Wen-Zhao Zhou,Yan-Mei Zhang,Jun-Ying Lu,Jun-Feng Li
International Journal of Molecular Sciences , 2012, DOI: 10.3390/ijms131013150
Abstract: To provide a resource of sisal-specific expressed sequence data and facilitate this powerful approach in new gene research, the preparation of normalized cDNA libraries enriched with full-length sequences is necessary. Four libraries were produced with RNA pooled from Agave sisalana multiple tissues to increase efficiency of normalization and maximize the number of independent genes by SMART? method and the duplex-specific nuclease (DSN). This procedure kept the proportion of full-length cDNAs in the subtracted/normalized libraries and dramatically enhanced the discovery of new genes. Sequencing of 3875 cDNA clones of libraries revealed 3320 unigenes with an average insert length about 1.2 kb, indicating that the non-redundancy of libraries was about 85.7%. These unigene functions were predicted by comparing their sequences to functional domain databases and extensively annotated with Gene Ontology (GO) terms. Comparative analysis of sisal unigenes and other plant genomes revealed that four putative MADS-box genes and knotted-like homeobox ( knox) gene were obtained from a total of 1162 full-length transcripts. Furthermore, real-time PCR showed that the characteristics of their transcripts mainly depended on the tight expression regulation of a number of genes during the leaf and flower development. Analysis of individual library sequence data indicated that the pooled-tissue approach was highly effective in discovering new genes and preparing libraries for efficient deep sequencing.
2,2′-[Octane-1,8-diyldioxybis(nitrilomethylidyne)]diphenol
Xiao-Jun Li,Jun-Feng Tong,Shang-Sheng Gong,Jian-Chao Wu
Acta Crystallographica Section E , 2010, DOI: 10.1107/s160053680905466x
Abstract: The complete molecule of the title compound, C22H28N2O4, is generated by a crystallographic inversion centre at the mid-point of the central C—C bond. The two benzene rings are parallel to each other with a perpendicular interplanar spacing of 1.488 (2) . Intramolecular O—H...N hydrogen bonds generate two six-membered rings with S(6) motifs. In the crystal, weak intermolecular C—H...O hydrogen bonds link neighbouring molecules into an infinite three-dimensional network, which is further stabilized by weak C—H...π interactions.
Virtual imaging anatomy of transnasal approach to the clivus
Jun-feng LI,Shou-sen WANG,Jun-jie JING,Ru-mi WANG
Medical Journal of Chinese People's Liberation Army , 2012,
Abstract: Objective  To observe the virtual anatomy via transnasal approach in a virtual-reality (VR) environment, and to establish a virtual anatomical model of clival region and explore the application value of the virtual-reality technology. Methods  Twenty patients (males 11, females 9, aged from 25 to 70 years old with a mean of 43±0.3 years ) with no pathological changes in the sellar area and clivus underwent CT angiography with Discovery Ultra 16 and 3.0T MRI thin-slice scan. The data were collected and inputted into the Dextroscope in the DICOM format. Virtual observation of anatomy via transnasal approach and three-dimensional reconstruction of clivus were carried out in the VR environment. Results  Virtual reconstruction and measurements of clivus were successfully performed in the 20 patients. The simulation of transnasal approach was also carried out in the VR environment. The lateral side of clival bone removal through transnasal approach was limited by internal carotid artery, the superior limit was sellar floor and the lower clivus could not be revealed completely because of the restriction of the maxilla and hard palate. Conclusions  Virtual reconstruction of the clivus and simulation of transnasal approach can be performed exactly by VR technology, which provides imaginal and anatomical basis in dealing with clivus lesions via transnasal approach.
Optimization of (002)-Oriented ZnO Film Synthesis in Sol-Gel Process and Film Photoluminescence Property

YAN Jun-Feng,ZHAO Li-Li,ZHANG Zhi-Yong,

中国物理快报 , 2008,
Abstract: By orthogonal design theory, technological parameters of the (002)-oriented ZnO film prepared in sol-gel process are optimized. A set of technological parameters for growing highly (002)-oriented ZnO film is obtained. As a result, it is proven that the Zn2+ concentration is the most important factor to grow a highly (002)-oriented ZnO film. We take an appropriate Zn2+ concentration 0.35mol/L for the aimed film, of which photoluminescence property is better than those of the films derived from other Zn2+ concentrations precursor solution. The Zn2+ concentration either larger or smaller than 0.35mol/L leads to the (002)-oriented degree decrease of films. By employing an atom force microscope, a hexagonal atom arrangement, which indicates that the film site detected is a ZnO single crystal, is observed in the surface of the highly (002)-oriented film.
2,2′-Dichloro-1,1′-[(pentane-1,5-diyldioxy)bis(nitrilomethylidyne)]dibenzene
Wen-Kui Dong,Jun-Feng Tong,Jian-Chao Wu,Li Li
Acta Crystallographica Section E , 2009, DOI: 10.1107/s1600536809027433
Abstract: The molecule of the title compound, C19H20Cl2N2O2, which lies across a crystallographic inversion centre, adopts a linear configuration. The dihedral angle between the two halves of the molecule is 5.14 (2)°. In the crystal structure, intermolecular C—H...O hydrogen bonds link neighbouring molecules into an infinite zigzag chain supramolecular structure.
Bis[(E)-4-bromo-2-(ethoxyiminomethyl)phenolato-κ2N,O1]copper(II)
Shang-Sheng Gong,Wen-Kui Dong,Jun-Feng Tong,Li Li
Acta Crystallographica Section E , 2009, DOI: 10.1107/s160053680904433x
Abstract: The title compound, [Cu(C9H9BrNO2)2], is a centrosymmetric mononuclear copper(II) complex. The Cu atom is four-coordinated in a trans-CuN2O2 square-planar geometry by two phenolate O and two oxime N atoms from two symmetry-related N,O-bidentate (E)-4-bromo-2-(ethoxyiminomethyl)phenolate oxime-type ligands. An interesting feature of the crystal structure is the centrosymmetric intermolecular Cu...O interaction [3.382 (1) ], which establishes an infinite chain structure along the b axis.
Page 1 /172001
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.