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Search Results: 1 - 10 of 13599 matches for " Fan Yingfang "
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Ultrasonic Measurement of Corrosion Depth Development in Concrete Exposed to Acidic Environment
Fan Yingfang,Hu Zhiqiang,Liu Jianglin
International Journal of Corrosion , 2012, DOI: 10.1155/2012/749185
Abstract: Corrosion depth of concrete can reflect the damage state of the load-carrying capacity and durability of the concrete structures servicing in severe environment. Ultrasonic technology was studied to evaluate the corrosion depth quantitatively. Three acidic environments with the pH level of 3.5, 2.5, and 1.5 were simulated by the mixture of sulfate and nitric acid solutions in the laboratory. 354 prism specimens with the dimension of 150?mm × 150?mm × 300?mm were prepared. The prepared specimens were first immersed in the acidic mixture for certain periods, followed by physical, mechanical, computerized tomography (CT) and ultrasonic test. Damage depths of the concrete specimen under different corrosion states were obtained from both CT and ultrasonic test. Based on the ultrasonic test, a bilinear regression model is proposed to estimate the corrosion depth. It is shown that the results achieved by ultrasonic and CT test are in good agreement with each other. Relation between the corrosion depth of concrete specimen and the mechanical indices such as mass loss, compressive strength, and elastic modulus is discussed in detail. It can be drawn that the ultrasonic test is a reliable nondestructive way to measure the damage depth of concrete exposed to acidic environment. 1. Introduction Since 1940s, pollution of acid rain has become to be a significant environmental problem confronting the environmentalists. In the past two decades, it is reported that acid rain falls have become more and more serious worldwide [1–6]. It is well known that concrete has become and will continue to be the most widely used construction material in civil engineering. However, when concrete is subject to acid rain, physical and chemical reactions occurred. The complex reactions will alter the internal structure of concrete, which will result in the change of its material property. Many famous buildings, such as Emei Mountain, Leshan Grand Buddha, Acropolis monument in Greece, and the Statue of Liberty in the United States, have been strongly damaged by acid rain in the previous decades. The damage effect of acid rain on concrete structures has attracted more and more attention of civil engineers gradually. A better understanding of the material properties of concrete exposed to acidic environment can help to discover the damage process of the in-service structures. Some experimental studies have been performed to discover the corrosion mechanism of acid rain attacking concrete, and simulation test of the acid rain attacking concrete was analyzed [7–12]. However, it is still
The Average Errors for the Grünwald Interpolation in the Wiener Space
Yingfang Du,Huajie Zhao
Discrete Dynamics in Nature and Society , 2009, DOI: 10.1155/2009/475320
Abstract: We determine the weakly asymptotically orders for the average errors of the Grünwald interpolation sequences based on the Tchebycheff nodes in the Wiener space. By these results we know that for the -norm (2≤≤4) approximation, the -average (1≤≤4) error of some Grünwald interpolation sequences is weakly equivalent to the -average errors of the best polynomial approximation sequence.
ERP dissociation and connection between implicit and explicit memory
YingFang Meng,ChunYan Guo
Chinese Science Bulletin , 2007, DOI: 10.1007/s11434-007-0459-7
Abstract: ERP dissociations between implicit and explicit memory have been confirmed by a large amount of evidence in theories of human memory. However, similarities between the two forms of memory have scarcely been studied. A possibility is that while implicit memory and explicit memory have independent components, they might additionally have shared components. To explore this question, an ERP experiment was conducted with a study-to-test paradigm, in which participants performed a “shallow” (color) study task or a “deep” (pleasant) study task, followed by either a lexical decision (implicit) test (Section 1) or a recognition (explicit) test (Section 2). An interference task was performed concurrently with either the encoding or the retrieval phase of the memory task for encoding interference condition or retrieval interference condition. We compared ERP signatures of implicit and explicit memory as a function of depth of processing or interference. Under the action of the same variables, 300–500 ms old/new ERP effects of implicit and explicit memory showed the same trend. These effects maybe all link with a perceptual representational system. 500–700 ms old/new ERP effects of the two memories were dissociated. They may probably reflect voluntary and involuntary recollection respectively. These results suggested that implicit and explicit memories are not completely independent of each other, but have both independent and shared components.

Chen Yuhe Zhou YingFang,

动物学研究 , 1992,
Abstract: 本文以C57BL/6J鼠分2组进行实验。实验组45鼠,对照组20鼠,与同品系雄鼠交配后,在3日龄胚期,通过腹部手术对实验组雌鼠每侧子宫腔内注入未稀释的H-Y抗血清与豚鼠补体(二者以1:2混合)3μl。抗血清是由C57BL/6L雌鼠用同品系雄鼠的脾细胞以2.5×10~7个/只的剂量,每周免疫一次,共免疫7次后制备。对照组的处理操作与实验组相同,但每侧子宫腔内仅注入补体3μl,未注入抗体。实验组中有42只产仔247只(每窝平均6只),雌雄比为2.7(180/67)雌性占73%;对照组20只均产仔共163只(每窝平均8只),雌雄比为0.92(78/85),雌性仔鼠占48%。实验组雌性仔鼠百分率比对照组提高了25%。据X~2检验结果表明,实验组与对照组间的差异很显著(P<0.001)。
Mountainous Freeway Risk Degree Forecast Model of Case Study: Mountainous Freeway Risk Degree Forecast Model of Case Study:
Chunbo Zhang,Yingfang Ma,Kuanmin Chen
Research Journal of Applied Sciences, Engineering and Technology , 2013,
Abstract: The objective of this study is to establish the mountainous freeway risk degree forecast model. Highway safety, especially mountainous freeway, relates to person, vehicle, road and environment four aspects including many factors. Firstly, this study analyzed some researches about the highway safety from these four aspects respectively. Secondly, this study considered many factors of these four aspects, established the mountainous freeway risk degree forecast model, listed the survey content needed in the forecast model. Finally, this study took Changjin Freeway in Jiangxi Province, China as example, used 91 accident data from January, 2006 to July, 2012, adopted the multiple linear regression method using spss 17.0 to obtain each parameter value of the forecast model and analyzed some parameter values to the mountainous freeway safety. The mountainous freeway risk degree forecast model is necessary and useful to evaluate the risk degree for constructed mountainous freeway, to estimate the safety of unconstructed mountainous freeway and to provide basis to improve mountainous freeway safety.
A Secure Mutual Authentication Protocol for Roaming in Wireless Mesh Networks
Peng Xiao,Jingsha He,Yingfang Fu
Journal of Networks , 2012, DOI: 10.4304/jnw.7.2.267-274
Abstract: Roaming in wireless mesh networks (WMNs) requires that mobile nodes complete access authentication fast while protecting the identities of mobile nodes. In this paper, after analyzing some current authentication protocols for roaming in wireless mesh networks, we propose a new protocol based on multi-signature and three-party key agreement with a zone-based hierarchical network topology and prove the security properties of the protocol through formal analysis that is based on the strand space model. We also demonstrate the reliability and performance of the proposed protocol through network simulations.
Structural and Functional Insights into Saccharomyces cerevisiae Riboflavin Biosynthesis Reductase RIB7
Zongyang Lv, Jian Sun, Yingfang Liu
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0061249
Abstract: Saccharomyces cerevisiae RIB7 (ScRIB7) is a potent target for anti-fungal agents because of its involvement in the riboflavin biosynthesis pathway as a NADPH-dependent reductase. However, the catalytic mechanism of riboflavin biosynthesis reductase (RBSRs) is controversial, and enzyme structure information is still lacking in eukaryotes. Here we report the crystal structure of Saccharomyces cerevisiae RIB7 at 2.10 ? resolution and its complex with NADPH at 2.35 ? resolution. ScRIB7 exists as a stable homodimer, and each subunit consists of nine central β-sheets flanked by five helices, resembling the structure of RIB7 homologues. A conserved G76-X-G78-Xn-G181-G182 motif is present at the NADPH pyrophosphate group binding site. Activity assays confirmed the necessity of Thr79, Asp83, Glu180 and Gly182 for the activity of ScRIB7. Substrate preference of ScRIB7 was altered by mutating one residue (Thr35) to a Lysine, implying that ScRIB7 Thr35 and its corresponding residue, a lysine in bacteria, are important in substrate-specific recognition.
Antirheumatoid Arthritis Activities and Chemical Compositions of Phenolic Compounds-Rich Fraction from Urtica atrichocaulis, an Endemic Plant to China
Mengyue Wang,Ke Li,Yuxiao Nie,Yingfang Wei,Xiaobo Li
Evidence-Based Complementary and Alternative Medicine , 2012, DOI: 10.1155/2012/818230
Abstract: Urtica atrichocaulis, an endemic plant to China, is commonly used to treat rheumatoid arthritis even though its pharmaceutical activities and chemical constituents were not studied. Herein, we reported our investigations on the chemical compositions of the phenolic compounds-rich fraction from U. atrichocaulis (TFUA) and their antirheumatoid arthritis activities. We found that the TFUA significantly inhibited the adjuvant-induced rats arthritis, carrageenin-induced rats paw edema, cotton pellet-induced mice granuloma, and the acetic acid-induced mice writhing response. Our phytochemical investigations on the TFUA resulted in the first-time isolation and identification of 17 phenolic constituents and a bis (5-formylfurfuryl) ether. The extensive HPLC analysis also revealed the chemical compositions of TFUA. Our further biological evaluation of the main phenolic components, individually and collectively, indicated that the antirheumatoid arthritis activities of TFUA were the combined effect of multiple phenolic constituents.
TRAF-mediated regulation of immune and inflammatory responses
YaYa Wang,Peng Zhang,YingFang Liu,GenHong Cheng
Science China Life Sciences , 2010, DOI: 10.1007/s11427-010-0050-3
Abstract: The tumor necrosis factor (TNF) receptor-associated factor (TRAF) family consists of six mammalian members, and is shown to participate in signal transduction of a large number of receptor families including TNF receptor family (TNFR) and Toll-like receptors-interleukin-1 receptors (TLR-IL-1R) family. Upon receptor activation, TRAFs are directly or indirectly recruited to the intracellular domains of these receptors. They subsequently engage other signaling proteins to activate inhibitor of κB kinase (IKK) complex, TRAF family member-associated NF-κB activator (TANK)-binding kinase 1 (TBK1) and inducible I κB kinase (IKK-i) (also known as IKK ), ultimately leading to activation of transcription factors such as NF-κB and interferon-regulatory factor (IRF) to induce immune and inflammatory responses.
Structure-function studies of the influenza virus RNA polymerase PA subunit
YingFang Liu,ZhiYong Lou,Mark Bartlam,ZiHe Rao
Science China Life Sciences , 2009, DOI: 10.1007/s11427-009-0060-1
Abstract: The influenza virus RNA-dependent RNA polymerase is a heterotrimeric complex (PA, PB1 and PB2) with multiple enzymatic activities for catalyzing viral RNA transcription and replication. The roles of PB1 and PB2 have been clearly defined, but PA is less well understood. The critical role of the polymerase complex in the influenza virus life cycle and high sequence conservation suggest it should be a major target for therapeutic intervention. However, until very recently, functional studies and drug discovery targeting the influenza polymerase have been hampered by the lack of three-dimensional structural information. We will review the recent progress in the structure and function of the PA subunit of influenza polymerase, and discuss prospects for the development of anti-influenza therapeutics based on available structures.
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