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OALib Journal期刊

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Molecular dynamics simulations of thermal conductivity and spectral phonon relaxation time in suspended and supported graphene
Bo Qiu,Xiulin Ruan
Physics , 2011, DOI: 10.1063/1.4712041
Abstract: We perform molecular dynamics (MD) simulations with phonon spectral analysis aiming at understanding the two dimensional (2D) thermal transport in suspended and supported graphene. Within the framework of equilibrium MD simulations, we perform spectral energy density (SED) analysis to obtain the lifetime of individual phonon modes. The per-mode contribution to thermal conductivity is then calculated to obtain the lattice thermal conductivity in the temperature range 300-650 K. In contrast to prior studies, our results suggest that the contribution from out-of-plane acoustic (or ZA) branch to thermal conductivity is around 25-30% in suspended single-layer graphene (SLG) at room temperature. The thermal conductivity is found to reduce when SLG is put on amorphous SiO2 substrate. Such reduction is attributed to the strengthened scattering in all phonon modes in the presence of the substrate. Among them, ZA modes are mostly affected with their contribution to thermal conductivity reduced to around 15%. As a result, thermal transport is dominated by in-plane acoustic phonon modes in supported SLG.
Coupling between Phonon-Phonon and Phonon-Impurity Scattering: A Critical Revisit of the Spectral Matthiessen's Rule
Tianli Feng,Bo Qiu,Xiulin Ruan
Physics , 2015, DOI: 10.1103/PhysRevB.92.235206
Abstract: The spectral Matthiessen's rule is commonly used to calculate the total phonon scattering rate when multiple scattering mechanisms exist. Here we predict the spectral phonon relaxation time $\tau$ of defective bulk silicon using normal mode analysis based on molecular dynamics, and show that the spectral Matthiessen's rule is not accurate due to the neglect of the coupling between anharmonic phonon-phonon scattering $\tau_a^{-1}$ and phonon-impurity scattering $\tau_i^{-1}$. As a result, the spectral Matthiessen's rule underestimates the total phonon scattering rate, and hence overestimates the thermal conductivity $\kappa$ of mass-doped and Ge-doped silicon by about 20-40%. We have also directly estimated this coupling scattering rate, so called coupled five-phonon scattering $\tau_{\rm couple}^{-1}$, and achieved good agreement between $\tau_a^{-1}+\tau_i^{-1}+\tau_{\rm couple}^{-1}$ and the total scattering rate $\tau_{tot}^{-1}$.
Hub-Accelerator: Fast and Exact Shortest Path Computation in Large Social Networks
Ruoming Jin,Ning Ruan,Bo You,Haixun Wang
Computer Science , 2013,
Abstract: Shortest path computation is one of the most fundamental operations for managing and analyzing large social networks. Though existing techniques are quite effective for finding the shortest path on large but sparse road networks, social graphs have quite different characteristics: they are generally non-spatial, non-weighted, scale-free, and they exhibit small-world properties in addition to their massive size. In particular, the existence of hubs, those vertices with a large number of connections, explodes the search space, making the shortest path computation surprisingly challenging. In this paper, we introduce a set of novel techniques centered around hubs, collectively referred to as the Hub-Accelerator framework, to compute the k-degree shortest path (finding the shortest path between two vertices if their distance is within k). These techniques enable us to significantly reduce the search space by either greatly limiting the expansion scope of hubs (using the novel distance- preserving Hub-Network concept) or completely pruning away the hubs in the online search (using the Hub2-Labeling approach). The Hub-Accelerator approaches are more than two orders of magnitude faster than BFS and the state-of-the-art approximate shortest path method Sketch for the shortest path computation. The Hub- Network approach does not introduce additional index cost with light pre-computation cost; the index size and index construction cost of Hub2-Labeling are also moderate and better than or comparable to the approximation indexing Sketch method.
Design of Drive System for Sensorless Brushless DC Motor Based on Model Reference Adaptive Control and Its Application in Horizontal Well Tractor  [PDF]
Zhou He, Yongjun Chen, Bo Ruan, Shuhan Yu, Junwen Zhou
Open Access Library Journal (OALib Journal) , 2018, DOI: 10.4236/oalib.1104267
Abstract:
The actual working environment temperature of the horizontal well tractor is too high, which leads to position sensor of general brushless DC motor (BLDCM) cannot work normally. Therefore, the position sensorless drive system is designed to overcome the problems caused by the position sensor in the actual working conditions. The principle of sensorless BLDCM work is introduced in detail, And drive system of Sensorless BLDCM was established by using simulation software. The use of three stage start make motor smoothly start, the motor speed detection based on model reference adaptive control (MRAC), ensures accurate commutation. Finally, the hardware and software design of the BLDCM system based on digital signal controller (DSC) is introduced and tested. The experimental results show that the drive system can start the BLDCM smoothly in the high temperature environment, and can quickly track the given speed, which meet the actual work demand of the horizontal well tractor.
Complete Solutions to Mixed Integer Programming  [PDF]
Ning Ruan
American Journal of Computational Mathematics (AJCM) , 2013, DOI: 10.4236/ajcm.2013.33B005
Abstract:

This paper considers a new canonical duality theory for solving mixed integer quadratic programming problem. It shows that this well-known NP-hard problem can be converted into concave maximization dual problems without duality gap. And the dual problems can be solved, under certain conditions, by polynomial algorithms.

The Internal Structure of Sha-henda: A Morphological Perspective  [PDF]
Jiacing Ruan
Open Journal of Modern Linguistics (OJML) , 2014, DOI: 10.4236/ojml.2014.44045
Abstract: Sha-henda (殺很大) “kill-very-big” which is coined from an advertisement of an on-line game has been being recently very popular in Taiwan society. With the effect of this slogan, people tends to analogize more and more new expressions, for example: sheng-henda (省很大) “save-very-big”, shui-henda (睡很大) “sleep-very-big”, and etc. Until 2013, the quantity of the coined expressions is still increasing. In the previous studies of Shen (2009), Xiao (2009), Liu (2010) and Liu (2012) on the structure of X-henda (X-很大), the structure is highly productive, involves an extreme or exaggerative meaning, is featured of rising tone, stress, and lengthening, and is initiated with a verb or an adjective. This present study argues henda in X-henda is a bound form (or a particle (助詞); Chao, 1979), similar to qilai (起來) in X-qilai or bude (不得) in X-bude, especially without objects or objects-preceding. With Distributed Morphology, a derivational analysis of the X-henda structure indicates that the function of henda intensifies the effect of sha to the extreme degree with rising tone, stress and lengthening to perform exaggeration on the object (in a sentence). The results may further contribute to grammaticalization analyses, verb-complement structure analyses and Chinese language teaching.
ESNOQ, Proteomic Quantification of Endogenous S-Nitrosation
Xixi Zhou,Peiwei Han,Jiangmei Li,Xu Zhang,Bo Huang,Hong-Qiang Ruan,Chang Chen
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0010015
Abstract: S-nitrosation is a post-translational protein modification and is one of the most important mechanisms of NO signaling. Endogenous S-nitrosothiol (SNO) quantification is a challenge for detailed functional studies. Here we developed an ESNOQ (Endogenous SNO Quantification) method which combines the stable isotope labeling by amino acids in cell culture (SILAC) technique with the detergent-free biotin-switch assay and LC-MS/MS. After confirming the accuracy of quantification in this method, we obtained an endogenous S-nitrosation proteome for LPS/IFN-γ induced RAW264.7 cells. 27 S-nitrosated protein targets were confirmed and using our method we were able to obtain quantitative information on the level of S-nitrosation on each modified Cys. With this quantitative information, over 15 more S-nitrosated targets were identified than in previous studies. Based on the quantification results, we found that the S-nitrosation levels of different cysteines varied within one protein, providing direct evidence for differences in the sensitivity of cysteine residues to reactive nitrosative stress and that S-nitrosation is a site-specific modification. Gene ontology clustering shows that S-nitrosation targets in the LPS/IFN-γ induced RAW264.7 cell model were functionally enriched in protein translation and glycolysis, suggesting that S-nitrosation may function by regulating multiple pathways. The ESNOQ method described here thus provides a solution for quantification of multiple endogenous S-nitrosation events, and makes it possible to elucidate the network of relationships between endogenous S-nitrosation targets involved in different cellular processes.
Optimisation of Prime–Boost Immunization in Mice Using Novel Protein-Based and Recombinant Vaccinia (Tiantan)-Based HBV Vaccine
Hong Chen, Xia Chuai, Yao Deng, Bo Wen, Wen Wang, Shaoqing Xiong, Li Ruan, Wenjie Tan
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0043730
Abstract: Background A therapeutic vaccine for chronic hepatitis B virus (HBV) infection that enhances virus-specific cellular immune responses is urgently needed. The “prime–boost” regimen is a widely used vaccine strategy against many persistence infections. However, few reports have addressed this strategy applying for HBV therapeutic vaccine development. Methodology/Principal Findings To develop an effective HBV therapeutic vaccine, we constructed a recombinant vaccinia virus (Tiantan) containing the S+PreS1 fusion antigen (RVJSS1) combined with the HBV particle-like subunit vaccine HBVSS1 to explore the most effective prime–boost regimen against HBV. The immune responses to different prime–boost regimens were assessed in C57BL/C mice by ELISA, ELISpot assay and Intracellular cytokine staining analysis. Among the combinations tested, an HBV protein particle vaccine priming and recombinant vaccinia virus boosting strategy accelerated specific seroconversion and produced high antibody (anti-PreS1, anti-S antibody) titres as well as the strongest multi-antigen (PreS1, and S)-specific cellular immune response. HBSS1 protein prime/RVJSS1 boost immunization was also generated more significant level of both CD4+ and CD8+ T cell responses for Th1 cytokines (TNF-α and IFN-γ). Conclusions The HBSS1 protein-vaccine prime plus RVJSS1 vector boost elicits specific antibody as well as CD4 and CD8 cells secreting Th1-like cytokines, and these immune responses may be important parameters for the future HBV therapeutic vaccines.
Effect of route of delivery on heterologous protection against HCV induced by an adenovirus vector carrying HCV structural genes
Jie Guan, Bo Wen, Yao Deng, Ke Zhang, Hong Chen, Xiaobing Wu, Li Ruan, Wenjie Tan
Virology Journal , 2011, DOI: 10.1186/1743-422x-8-506
Abstract: A recombinant replication-defective adenovirus serotype 5 (rAd5) vector, rAd5-CE1E2, and a recombinant Tian Tan vaccinia vector, rTTV-CE1E2, were constructed to express the HCV CE1E2 gene (1-746 amino acid HCV 1b subtype). Mice were prime-immunised with rAd5-CE1E2 delivered via intramuscular injection (i.m.), intranasal injection (i.n.), or intradermal injection (i.d.) and boosted using a different combination of injection routes. CMI was evaluated via IFN-γ ELISPOT and ICS 2 weeks after immunisation, or 16 weeks after boost for long-term responses. The humoral response was analysed by ELISA. With the exception of priming by i.n. injection, a robust CMI response against multiple HCV antigens (core, E1, E2) was elicited and remained at a high level for a long period (16 weeks post-vaccination) in mice. However, i.n. priming elicited the highest anti-core antibody levels. Priming with i.d. rAd5-CE1E2 and boosting with i.d. rTTV-CE1E2 carried out simultaneously enhanced CMI and the humoral immune response, compared to the homologous rAd5-CE1E2 immune groups. All regimens demonstrated equivalent cross-protective potency in a heterologous surrogate challenge assay based on a recombinant HCV (JFH1, 2a) vaccinia virus.Our data suggest that a rAd5-CE1E2-based HCV vaccine would be capable of eliciting an effective immune response and cross-protection. These findings have important implications for the development of T cell-based HCV vaccine candidates.Hepatitis C virus (HCV) is one of the major agents of acute and chronic hepatitis worldwide [1,2]. Around 80% of HCV infections progress to chronic hepatitis. In turn, chronic hepatitis C infection frequently progresses to cirrhosis, and a significant proportion of patients with liver cirrhosis will develop hepatocellular carcinoma (HCC) [3]. Treatment of chronic hepatitis C with interferon alpha and ribavirin is effective in less than 50% of cases [4,5]. Considerable effort has been directed toward development of a safe and ef
Multi-scale analysis on wintering habitat selection of Reeves''s Pheasant (Syrmaticus reevesii) in Dongzhai National Nature Reserve, Henan Province, China

Jiliang Xu,Xiaohui Zhang,Zhengwang Zhang,Guangmei Zheng,Xiangfeng Ruan,Jiagui Zhu,Bo Xi,

生态学报 , 2006,
Abstract: Reeves's Pheasant (Syrmaticus reevesii), endemic to China, is an endangered species of pheasants. The wintering habitat selection by the species was investigated at three scales (10, 115 m and 250 m) in Dongzhai National Nature Reserve from 2000 to 2002. At each scale, a range of habitat variables were compared between the used and the control sites. At the smallest scale (10 m), the variables influencing wintering habitat selection were slope, tree cover, and the interaction between the cosine of slope aspect and the shrub height. At the mid-scale (115 m), the area of shrub, the area of broad-leaved forest, and the area of conifer forest were the key factors. At the largest scale (250 m), broad-leaved and conifer forest coverages and their interaction were the key factors. According to the lowest AIC and AICc values at the mid-scale, the characteristics at this scale were stated as the ultimate factors influencing the habitat selection of the bird. When a range of habitat variables at all scales within a multivariate regression were considerred, the most important variables were conifer forest coverage at the mid-scale, broad-leaved forest coverage, and the interaction between the conifer forest and shrub coverages at the large-scale, and the distance to beach and farmland. These results highlight the importance of multiscale analyses when habitat selection by pheasants are considerred.
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