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Search Results: 1 - 10 of 18611 matches for " Junping Peng "
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Numerical Calculation of Dynamic Response for Multi-Span Non-Uniform Beam Subjected to Moving Mass with Friction  [PDF]
Junping Pu, Peng Liu
Engineering (ENG) , 2010, DOI: 10.4236/eng.2010.25048
Abstract: In order to simulate the coupling vibration of a vehicle or train moves on a multi-span continuous bridge with non-uniform cross sections, a moving mass model is used according to the Finite Element Method, the effect of the inertial force, Coriolis force and centrifugal force are considered by means of the additive matrices. For a non-uniform rectangular section beam with both linear and parabolic variable heights in a plane, the stiffness and mass matrices of the beam elements are presented. For a non-uniform box girder, Romberg numerical integral scheme is adopted, each coefficient of the stiffness matrix is obtained by means of a normal numerical computation. By applying these elements to calculate the non-uniform beam, the computational accuracy and efficiency are improved. The finite element method program is worked out and an entire dynamic response process of the beam with non-uniform cross sections subjected to a moving mass is simulated numerically, the results are compared to those previously published for some simple examples. For some complex multi-span bridges subjected to some moving vehicles with changeable velocity and friction, the computational results, which can be regarded as a reference for engineering design and scientific research, are also given simultaneously.
An Integrated Approach for Finding Overlooked Genes in Shigella
Junping Peng,Jian Yang,Qi Jin
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0018509
Abstract: The completion of numerous genome sequences introduced an era of whole-genome study. However, many genes are missed during genome annotation, including small RNAs (sRNAs) and small open reading frames (sORFs). In order to improve genome annotation, we aimed to identify novel sRNAs and sORFs in Shigella, the principal etiologic agents of bacillary dysentery.
Research progress in Shigella in the postgenomic era
JunPing Peng,Jian Yang,Qi Jin
Science China Life Sciences , 2010, DOI: 10.1007/s11427-010-4089-y
Abstract: Gram-negative, facultative intracellular anaerobes of the genus Shigella, the principal etiologic agents of shigellosis, continue to pose a threat to public health. Shigellosis causes 1.1 million deaths with over 164 million annual cases. The Shigella spp. can be divided into four serogroups: Shigella dysenteriae, Shigella flexneri, Shigella boydii and Shigella sonnei. The completion of seven Shigella genome sequences of representative strains from each of the Shigella species has introduced an era of whole-genome study. This paper reviews contemporary understanding of genomics, transcriptomics, proteomics and the structural biology of Shigella.
Dynamic Response Analysis of Beams with Oblique Collision  [PDF]
Junping Pu, Yandong Chi
Engineering (ENG) , 2011, DOI: 10.4236/eng.2011.37095
Abstract: Adopting a dynamic contact numerical method, some problems such as the central collision, transverse collision and oblique collision between two beams are researched. Numerical expressions for these cases are deduced. Using a self-developed finite element program some examples are computed, and compared with the analytical solution of the central collision, this numerical algorithm is proved to be reliable. For the other numerical results that have no analytical solution to be used to compare with, they are also reasonable through the theoretical analysis. For the transverse and oblique collision, the ideal results can be obtained by using a smaller time step.
The Effect of Habitus and Capitals on Adoption Behavior of E-Commerce Information System: An Investigation of Digital Immigrants  [PDF]
Huifen Wang, Junping Wang
Open Journal of Social Sciences (JSS) , 2017, DOI: 10.4236/jss.2017.54015
Abstract: With the rapid development of e-commerce, more and more digital immigrants actively participate in online shopping. However, some may be more skilled in using e-commerce information system (e-commerce IS), while others still meet some barriers doing so. Thus, it is interesting to investigate the e-commerce IS adoption behavior of digital immigrants. To understand the critical resources that contribute to the different behaviors between the digital immigrants, we attempt to operationalize the capital perspective, drew on Bourdieu’s practice theory and propose a research model to investigate: 1) the forms of capital and habitus for using e-commerce IS; 2) what is the relationship between digital immigrant’s capital, habitus and e-commerce IS adoption behavior. Based on the data collected from 334 digital immigrants in China, we empirically test the proposed model. To ensure the validity and reliability of the instrument, factor analysis and reliability test were conducted. The results of multiple regression analysis demonstrate the significant effects of habitus and capitals on digital immigrants’ e-commerce IS adoption, especially the intrinsic motivation and propensity to informatization dimension of habitus, the social influence and social support dimension of social capital. Implications of the findings as well as limitations of the study and directions for future research are also discussed.
The Immunologic Injury Composite with Balloon Injury Leads to Dyslipidemia: A Robust Rabbit Model of Human Atherosclerosis and Vulnerable Plaque
Guangyin Zhang,Ming Li,Liangjun Li,Yingzhi Xu,Peng Li,Cui Yang,Yanan Zhou,Junping Zhang
Journal of Biomedicine and Biotechnology , 2012, DOI: 10.1155/2012/249129
Abstract: Atherosclerosis is a condition in which a lipid deposition, thrombus formation, immune cell infiltration, and a chronic inflammatory response, but its systemic study has been hampered by the lack of suitable animal models, especially in herbalism fields. We have tried to perform a perfect animal model that completely replicates the stages of human atherosclerosis. This is the first combined study about the immunologic injury and balloon injury based on the cholesterol diet. In this study, we developed a modified protocol of the white rabbit model that could represent a novel approach to studying human atherosclerosis and vulnerable plaque.
Common Changes in Global Gene Expression Induced by RNA Polymerase Inhibitors in shigella flexneri
Hua Fu, Liguo Liu, Xiaobing Zhang, Yafang Zhu, Lina Zhao, Junping Peng, Hongxuan He, Qi Jin
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0033240
Abstract: Characterization of expression profile of organisms in response to antimicrobials provides important information on the potential mechanism of action of the drugs. The special expression signature can be used to predict whether other drugs act on the same target. Here, the common response of Shigella flexneri to two inhibitors of RNA polymerase was examined using gene expression profiling. Consistent with similar effects of the two drugs, the gene expression profiles indicated that responses of the bacteria to these drugs were roughly the same, with 225 genes affected commonly. Of them, 88 were induced and 137 were repressed. Real-time PCR was performed for selected genes to verify the microarray results. Analysis of the expression data revealed that more than 30% of the plasmid-encoded genes on the array were up-regulated by the antibiotics including virF regulon, other virulence-related genes, and genes responsible for plasmid replication, maintenance, and transfer. In addition, some chromosome-encoded genes involved in virulence and genes acquired from horizontal transfer were also significantly up-regulated. However, the expression of genes encoding the beta-subunit of RNA polymerase was increased moderately. The repressed genes include those that code for products associated with the ribosome, citrate cycle, glycolysis, thiamine biosynthesis, purine metabolism, fructose metabolism, mannose metabolism, and cold shock proteins. This study demonstrates that the two antibiotics induce rapid cessation of RNA synthesis resulting in inhibition of translation components. It also indicates that the production of virulence factors involved in intercellular dissemination, tissue invasion and inflammatory destruction may be enhanced through derepressing horizontal transfer genes by the drugs.
Hydrogenation of Ethyl Acetate to Ethanol over Ni-Based Catalysts Obtained from Ni/Al Hydrotalcite-Like Compounds
Beixiao Zhang,Lu Lin,Junping Zhuang,Ying Liu,Lincai Peng,Longfei Jiang
Molecules , 2010, DOI: 10.3390/molecules15085139
Abstract: A series of Ni-based catalysts were prepared using hydrogen reduction of Ni/Al hydrotalcite-like compounds (Ni/Al HTlcs) synthesized by coprecipitation. The physico-chemical properties of Ni/Al hydrotalcite-like compounds and the corresponding Ni-based catalysts were characterized using inductively coupled plasma (ICP), BET surface areas, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) techniques. The results indicated that Ni/Al HTlcs with layered structures could be successfully prepared by the coprecipitation method, and the characteristic HTlcs reflections were also observed in the XRD analysis. The NiO and Ni0 phases were identified in all Ni-based catalysts, which displayed randomly interconnected pores and no layer structures. In addition, the studies also found the Ni/Al HTlcs and Ni-based catalysts had high specific surface areas, low pore volumes and low pore diameters. The catalytic hydrogenation of ethyl acetate to ethanol with Ni-based catalysts was also investigated. Among the studied catalysts, RE1NASH-110-3 showed the highest selectivity and yield of ethyl acetate to ethanol, which were 68.2% and 61.7%, respectively. At the same time, a major by-product, butyl acetate, was formed due to an ester-exchange reaction. A proposed hydrogenation pathway for ethyl acetate over Ni-based catalysts was suggested.
Catalytic Conversion of Cellulose to Levulinic Acid by Metal Chlorides
Lincai Peng,Lu Lin,Junhua Zhang,Junping Zhuang,Beixiao Zhang,Yan Gong
Molecules , 2010, DOI: 10.3390/molecules15085258
Abstract: The catalytic performance of various metal chlorides in the conversion of cellulose to levulinic acid in liquid water at high temperatures was investigated. The effects of reaction parameters on the yield of levulinic acid were also explored. The results showed that alkali and alkaline earth metal chlorides were not effective in conversion of cellulose, while transition metal chlorides, especially CrCl3, FeCl3 and CuCl2 and a group IIIA metal chloride (AlCl3), exhibited high catalytic activity. The catalytic performance was correlated with the acidity of the reaction system due to the addition of the metal chlorides, but more dependent on the type of metal chloride. Among those metal chlorides, chromium chloride was found to be exceptionally effective for the conversion of cellulose to levulinic acid, affording an optimum yield of 67 mol % after a reaction time of 180 min, at 200 °C, with a catalyst dosage of 0.02 M and substrate concentration of 50 wt %. Chromium metal, most of which was present in its oxide form in the solid sample and only a small part in solution as Cr3+ ion, can be easily separated from the resulting product mixture and recycled. Finally, a plausible reaction scheme for the chromium chloride catalyzed conversion of cellulose in water was proposed.
Characterization of serogroup C meningococci isolated from 14 provinces of China during 1966–2005 using comparative genomic hybridization
JunPing Peng,XiaoBing Zhang,E. Yang,Jing Wang,Jian Yang,ZhuJun Shao,Qi Jin
Science China Life Sciences , 2007, DOI: 10.1007/s11427-007-0016-2
Abstract: Neisseria meningitidis is a major cause of bacterial meningitis and septicemia worldwide. In China, serogroup A strains were responsible for over 95% of the cases, while serogroup C strains were only recovered from a few sporadic cases. However, a sudden increase in the number of cases due to serogroup C strains occurred during 2003–2005 in Anhui Province, China. Many cases were found in other provinces at the same time. Multilocus sequence typing (MLST) results indicated that the unique sequence type 4821 clone meningococci, a new hyper-virulent lineage, was responsible for the serogroup C meningitis outbreaks. We have completed the project of sequencing the whole genome of the Chinese N. meningitidis serogroup C representative isolate 053442. We fabricated a whole-genome microarray of N. meningitidis isolate 053442 and analyzed the genome composition differences among 81 serogroup C isolates which were isolated from 14 provinces of China during 1966–2005. The comparative genomic hybridization (CGH) result shows that the genome compositions of nearly all serogroup C isolates are similar to that of 053442. The products of many absent open reading frames (ORFs) are conserved hypothetical proteins. The results will provide a valuable resource from which one can analyze the genome composition and genetic background of serogroup C meningococci in China.
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