Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Any time

2020 ( 5 )

2019 ( 30 )

2018 ( 239 )

2017 ( 242 )

Custom range...

Search Results: 1 - 10 of 16216 matches for " Jianxun Qi "
All listed articles are free for downloading (OA Articles)
Page 1 /16216
Display every page Item
Prediction of nonregular secondary structures of proteins based on wavelet analysis
Jianxun Qi,Yi Xiao
Chinese Science Bulletin , 2002, DOI: 10.1360/02tb9206
Abstract: The secondary structures of proteins fall into two classes: regular structure and nonregular structure. Helices and sheets are termed “regular” structures because their residues have repeating main-chain torsion angles, and their backbone N-H and C-O groups are arranged in a periodic pattern of hydrogen bonding. In contrast, the remaining structures with nonrepeating backbone torsion angles are called nonregular secondary structures. In this note, we performed an extensive sequence analysis of nonregular secondary structures and showed that these nonregular parts could be effectively predicted by continuous wavelet transform.
Microstructure Evolution of Grade X100 Pipeline under Plastic Deformation Condition
Lihua Qi,Long Yang,Jing Niu,Yaorong Feng,Jianxun Zhang
Advances in Materials Science and Engineering , 2010, DOI: 10.1155/2010/180975
Abstract: The effects of plastic deformation on the microstructure evolution of grade X100 pipeline were investigated by SEM, TEM and EBSD tests. The result shows that quasipolygon ferrite deforms firstly under plastic strain initial stage, then both acicular ferrite and granular bainite change remarkably with the value of plastic strain increase. When the tension stress reaches the tensile strength, microcracks nucleate around the inclusion and M/A constitute, expand with the plastic deformation increases, and finally cracks connection causes the crack penetration until the expiration. Furthermore, the microscopic orientation concentrates in ? direction before the deformation, while crystal orientation in and direction enhanced after the deformation. 1. Introduction At present, requirement for natural gas is rapidly increasing internationally. Pipeline is used for crude oil and natural gas transmission over long distance. Recent researches indicated that there are significant advantages of using higher grade line pipes, such as X100 even X120 grade pipeline, in constructing long distance pipeline, because it can improve transportation efficiency of the natural gas pipelines by increasing internal transportation pressure, and material cost can be saved correspondingly by reducing wall thickness of pipe body and consumable for girth welding [1–5]. However, there are still many transportation safety problems laying high strength pipelines. First of all, due to line pipes laid through complicated regions, such as earthquake region with high-risk, gas pipelines in service may endure large displacement and stress. Secondly, It was reported that the crosswise strain rate of UOE pipeline achieves 2% in the manufacture process, and the maximum flexure deformation at part of the pipeline reaches to 4%~5% when it lays through multiple-region of earthquake and geology casualty [6–10]. Thirdly, there are a lot of natural gas let-out or exploration accidents due to pipeline plastic fracture in the world. Therefore, in order to guarantee property stability and operational safety of the pipeline, it is necessary to research the microstructure evolution mechanism under plastic deformation condition. In this paper, the grade X100 pipeline microstructure and texture transformation were investigated during the in situ plastic tensile process. 2. Experimental Metallographic, SEM, EBSD, and TEM experiments samples were prepared at 1/4 thickness position of the pipelines steel, which ingredients (w%) are C 0.064, Si 0.095, Mn 1.69, Cr 0.013, Mo 0.031, Ni 0.2, Nb 0.042. In situ SEM
Blow-up formulae of high genus Gromov-Witten invariants in dimensional six
Weiqiang He,Jianxun Hu,Hua-Zhong Ke,Xiaoxia Qi
Mathematics , 2014,
Abstract: Using the degeneration formula and absolute/relative correspondence, one studied the change of Gromov-Witten invariants under blow-up for six dimensional symplectic manifolds and obtained closed blow-up formulae for high genus Gromov-Witten invariants. Our formulae also imply some relations among generalized BPS numbers introduced by Pandharipande.
Characterization and Modeling of Urban Water Quality in the City of Calgary, Canada  [PDF]
Dhiraj Shrestha, Jianxun He
Natural Resources (NR) , 2017, DOI: 10.4236/nr.2017.88032
Abstract: Non-point source pollution (NPS) besides point source pollution (PS) has contributed to pollutant loading into natural receiving water bodies. Due to the nature of NPS, the quantification of pollutant loading from NPS is very challenging but crucial to riverine water quality management, especially for the river reach flowing through urban areas. The water quality in the river reach of the Bow River flowing through the City of Calgary in Alberta, Canada, is affected by both PS and NPS. Thus, understanding and characterizing water quality of discharges (affected by NPS) into the river reach is necessary for better managing riverine water quality and preventing water quality degradation. In the paper, monitored event mean concentrations (EMCs) of stormwater runoff and mean concentrations of snowmelt and baseflow of seven common pollutants from sub-catchments, which are categorized into four land use types including commercial, industrial, residential and on-going development land uses, were used to investigate the linkage between land use and water quality. Statistical analysis techniques were adopted to identify differences or similarities in water quality among different flow types, different land use types, and among/between catchments of same land use. The results indicated that EMCs of many water quality parameters vary among different land use types and among/between catchments of same land use. The results also showed median EMCs of pollutants of snowmelt and baseflow are, in general, lower than those of stormwater runoff. In addition, Stormwater Management Model was employed to investigate the physical process that would affect water quality response to storm events for two typical land uses, industrial and residential land uses. The modeling results supported that wash-off of particulate matters might primarily affect water quality response of catchments between different land uses. All the results shed the light on the necessity of quantifying pollutant loading considering the characteristics of land uses.
The Practical Method of Drawing a Dummy Activity

Jin Qi,Qi Jianxun,Liu Hongyan,
靳 祁

系统工程理论与实践 , 1998,
Abstract: This article deals with the practical method instead of the optimal method of drawing a dummy activity.First,the article illustrated the simplest programmed drawing method of a dummy activity.Second,it discussed the practical drawing method,which had not been mentioned worldwide yet,of a dummy activity when adjusting the network chart.Furthermore,it put forward the idea of "the most,the first principle",and the "redundency principle",which,in most cases,are not only practical but also optimal.
Reciprocity between abscisic acid and ethylene at the onset of berry ripening and after harvest
Liang Sun, Mei Zhang, Jie Ren, Jianxun Qi, Guojun Zhang, Ping Leng
BMC Plant Biology , 2010, DOI: 10.1186/1471-2229-10-257
Abstract: The expressions of VvNCED1 encoding 9-cis-epoxycarotenoid dioxygenase (NCED) and VvGT encoding ABA glucosyltransferase were all increased rapidly at the stage of véraison and reached the highest level at 9th week after full bloom. However, VvCYP1 encoding ABA 8'-hydroxylase and VvβG1 encoding berry β-glucosidase are different, whose expression peak appeared at the 10th week after full bloom and in especial VvβG1 remained at a high level till harvest. The VvACO1 encoding 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase, the VvETR2 (ethylene response 2) and VvCTR1 (constitutive triple response 1) had a transient expression peak at pre-véraison, while the VvEIN4 (ethylene insensitive 4) expression gradually increased from the véraison to one week before harvest stage. The above mentioned changes happened again in the berry after harvest. At one week before véraison, double block treatment with NiCl2 plus 1-methylcyclopropene (1-MCP) not only inhibited the release of ethylene and the expression of related genes but also suppressed the transcription of VvNCED1 and the synthesis of ABA which all might result in inhibiting the fruit ripening onset. Treatment with ABA could relieve the double block and restore fruit ripening course. However, after harvest, double block treatment with NiCl2 plus 1-MCP could not suppress the transcription of VvNCED1 and the accumulation of ABA, and also could not inhibit the start of fruit senescence.The trace endogenous ethylene induces the transcription of VvNCED1 and then the generation of ABA followed. Both ethylene and ABA are likely to be important and their interplaying may be required to start the process of berry ripening. When the level of ABA reached the peak value, part of it will be stored in the form of ABA-GE. While after harvest, abiotic stresses principally (such as dehydration, harvest shock) could induce the transcription of VvNCED1 and the accumulation of ABA, thus starting the process of fruit senescence.Fruits can be
Local Gromov-Witten invariants of Blowups of Fano surfaces
Jianxun Hu
Mathematics , 2010, DOI: 10.1016/j.geomphys.2011.02.004
Abstract: In this paper, using the degeneration formula we obtain a blowup formulae of local Gromov-Witten invariants of Fano surfaces. This formula makes it possible to compute the local Gromov-Witten invariants of non-toric Fano surfaces form toric Fano surface, such as del Pezzo surfaces. This formula also verifed an expectation of Chiang-Klemm-Yau-Zaslow.
Local Donaldson-Thomas invariants of Blowups of surfaces
Jianxun Hu
Mathematics , 2011,
Abstract: Using the degeneration formula for Donaldson-Thomas invariants, we proved a formula for the change of Donaldson-Thomas invariants of local surfaces under blowing up along points.
Gromov-Witten Invariants of Blow-ups Along Points and Curces
Jianxun Hu
Mathematics , 1998,
Abstract: In this paper, using the gluing formula of Gromov-Witten invariants under symplectic cutting, due to Li and Ruan, we studied the Gromov-Witten invariants of blow-ups at a smooth point or along a smooth curve. We established some relations between Gromov-Witten invariants of M and its blow-ups at a smooth point or along a smooth curve.
Insight into the Interaction of Metal Ions with TroA from Streptococcus suis
Beiwen Zheng,Qiangmin Zhang,Jia Gao,Huiming Han,Ming Li,Jingren Zhang,Jianxun Qi,Jinghua Yan,George F. Gao
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0019510
Abstract: The scavenging ability of sufficient divalent metal ions is pivotal for pathogenic bacteria to survive in the host. ATP-binding cassette (ABC)-type metal transporters provide a considerable amount of different transition metals for bacterial growth. TroA is a substrate binding protein for uptake of multiple metal ions. However, the function and structure of the TroA homologue from the epidemic Streptococcus suis isolates (SsTroA) have not been characterized.
Page 1 /16216
Display every page Item

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