Practical method for determining load and resistance factors using third-moment transformation

Pei-Pei Li,Zhao-Hui Lu,Yan-Gang Zhao 국제구조공학회 2021 Structural Engineering and Mechanics, An Int'l Jou Vol.80 No.2

Load and resistance factor design (LRFD) is a suitable format for the reliability-based limit state design of structures. It has been adopted in many countries, such as the United States, Europe, Canada, and Japan. Usually, the first-order reliability method (FORM) is used to estimate the load and resistance factors, but it requires the determination of design points and complicated double iterative computations. Therefore, FORM is not easy or practical for engineers to use. This paper presents a simple, accurate method to determine the load and resistance factors utilizing the third-moment transformation, which does not require derivative-based iterations and can estimate the load and resistance factors without using the distribution of random variables. In addition, the proposed method provides enough accurate results within a wide range of target reliability indices. Therefore, this method should be effective and convenient for calculating the load and resistance factors in actual practice. Five numerical examples illustrate the proposed method’s efficiency and accuracy; FORM provides a benchmark for comparison.

Preparation of stable gelatin/sodium carboxymethylcellulose/sodium lauryl sulfonate microcapsules with ultra-thin capsule wall for electrophoretic displays

Gang Wu,Run-Ying Dai,Weigang Li,Pei-Pei Yin,Hongzheng Chen,Mang Wang 한국물리학회 2011 Current Applied Physics Vol.11 No.3

Elastic and optical transparent microcapsules with ultra-thin and compact capsule wall for electrophoretic display containing tetrachloroethylene as core material were prepared from gelatin (GE), sodium lauryl sulfonate (SLS) and sodium carboxymethylcellulose (NaCMC) by complex coacervation method. Microcapsules were characterized by scanning electron microscopy, optical microscopy, and thermogravimetric analysis. The pH value influenced formation process was monitored by recording the microstructure of the fragment of the capsules formed at different pH value. Products with branch-like structure formed with the decrease of pH value, by which the capsule wall was knitted up to form compact structure. SLS was found to play an important role in the course of capsule formation, i.e. SLS helped to increase the interaction between gelatin and NaCMC and facilitate the complex coacervation reaction. In the case of 1.0 mM SLS addition, GE/NaCMC/SLS microcapsules with ultra-thin capsule wall,200 nm in thickness, can be prepared. The capsule owns high thermal stability and good barrier property,both of which prevent core materials from penetrating outside the capsules and are favor of the practical application for the capsules in areas of electrophoretic displays.

Catalytic enantioselective synthesis of α-chiral azides

Ding, Pei-Gang,Hu, Xiao-Si,Zhou, Feng,Zhou, Jian The Royal Society of Chemistry 2018 ORGANIC CHEMISTRY FRONTIERS Vol.5 No.9

<P>α-Chiral azides represent a special subclass of chiral amines, which not only widely exist in bioactive compounds but also play a significant role as a building block in a variety of value-added chiral products. The catalytic asymmetric synthesis of α-chiral azides is of current interest and three synthetic strategies have been developed. This review summarizes the recent progress in this research area, discusses the advantages and limitations of each strategy, and outlines synthetic opportunities for future research.</P>

Performance improvement of amorphous indium-gallium-zinc oxide ReRAM with SiO2 inserting layer

Yanli Pei,Biaoren Mai,Xiaoke Zhang,Ruiqin Hu,Ya Li,Zimin Chen,Bingfeng Fan,Jun Liang,Gang Wang 한국물리학회 2015 Current Applied Physics Vol.15 No.4

In this study, the resistive switching performance of amorphous indiumegalliumezinc oxide (a-IGZO) resistive switching random-access memory (ReRAM) was improved by inserting a thin silicon oxide layer between silver (Ag) top electrode and a-IGZO resistive switching layer. Compared with the single a-IGZO layer structure, the SiO2/a-IGZO bi-layer structure exhibits the higher On/Off resistance ratio larger than 103, and the lower operation power using a smaller SET compliance current. In addition, good endurance and excellent retention characteristics were achieved. Furthermore, multilevel resistance states are obtained through adjusting SET compliance current and RESET stop voltage, which shows a promise for high-performance nonvolatile multilevel memory application.

Electronic and Optical Properties of Noble Metal Oxides M2O (M = Cu, Ag and Au): First-principles Study

Fei Pei,Song Wu,Gang Wang,Ming Xu,Liang-Yao Chen,Yu Jia,Song-You Wang 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.55 No.3

In this work, first-principles calculations for the structural, electronic, and optical properties of noble metal oxides M2O (M = Cu, Ag, Au) with the cuprite structure are performed by using a plane wave pseudopotential method in the framework of density functional theory (DFT) and the generalized gradient approximation (GGA). The structural, electronic, and optical properties are investigated and discussed. For Cu2O and Ag2O, good agreement was achieved between calculated and experimental results. Within the same framework, Au2O is predicted to be a semiconductor. In comparison with the copper and the silver oxides, the gold oxide has less ionic bonding between Au and O, and the intra-atomic hybridization is expected to be more evident as the depletion of the Au 5d shell appears to be more profound than it is for the Cu 3d and the Ag 4d shells. In this work, first-principles calculations for the structural, electronic, and optical properties of noble metal oxides M2O (M = Cu, Ag, Au) with the cuprite structure are performed by using a plane wave pseudopotential method in the framework of density functional theory (DFT) and the generalized gradient approximation (GGA). The structural, electronic, and optical properties are investigated and discussed. For Cu2O and Ag2O, good agreement was achieved between calculated and experimental results. Within the same framework, Au2O is predicted to be a semiconductor. In comparison with the copper and the silver oxides, the gold oxide has less ionic bonding between Au and O, and the intra-atomic hybridization is expected to be more evident as the depletion of the Au 5d shell appears to be more profound than it is for the Cu 3d and the Ag 4d shells.

The Situation, Models and Strategies of Forage Production in Beijing

Lin Meng,Pei-chun Mao,Lie-gang Han,Guo-fang Zhang 한국초지조사료학회 2009 한국초지조사료학회 학술대회논문집 Vol.2009 No.08

The situation, problems and models of forage production and industrialization in Beijing were analyzed, and the strategies were pointed out including: (1) The suitable planting areas for alfalfa, silage com and rye etc should be defined systemically, and the rational harvest time and dry skills should be set up in Beijing plain areas. (2) The perennial forage crops with higher drought resistance should be planted in the waste slope land and barren land. (3) The interplant forage crops in the woodland and orchard should be generalized.

Fe/N-doped carbon framework derived from ZIF-8 on graphene oxide for efficient oxygen reduction reaction

Yating Zhang,Pei He,Dongxian Zhuo,Jianlan Zhang,Nana Zhang,Xiaobo Wang,Gang Lin,Zhenghan Kong 대한금속·재료학회 2024 ELECTRONIC MATERIALS LETTERS Vol.20 No.2

Exploration of highly effi cient non-noble metal oxygen reduction reaction (ORR) catalysts is essential for the widespreadindustrial utilization of fuel cells. Herein, we demonstrated a hierarchical porous catalyst (denoted as Fe-NC-Gs) using asimple stirring and one-step pyrolysis method. ZIF-8-derived N-doped carbon framework loaded on graphene oxide, on whichFe 3 O 4 and FeS nanoparticles are uniformly dispersed. In the composite nanostructure, a high surface area (470.58 m 2 g −1 )and hierarchical porous structure were observed. The obtained Fe-NC-G-2 exhibits superior ORR properties. The half-wavepotential (E 1/2 ) and the limiting current density in alkaline media were up to 0.85 V and − 5.39 mA cm −2 , respectively, comparableto the commercially available Pt/C. The four-electron-dominated process was exhibited in the ORR catalysis. It alsomanifests a better methanol tolerance and electrochemical stability during the chronoamperometry measurement in 0.1 MKOH. These results suggest that the proposed strategy provides a new pathway to construct effi cient electrocatalysts for ORR.

Theoretical Study on the Point Defects in N-Doped Anatase TiO2

Song-You Wang,Fei Pei,Song Wu,Gang Wang,Ming Xu,Liang-Yao Chen,Yu Jia 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.4

In this work, first-principles calculations for the electronic and the optical properties of titanium dioxide (TiO2) with point defects are performed by using a plane wave pseudopotential method in the framework of the density functional theory and the generalized gradient approximation. The point defects, substitutional and interstitial nitrogen, in anatase TiO2 are investigated to understand the origin of the visible-light sensitivity of nitrogen (N)-doped TiO2. The results show that bands originating from substitutional N 2p states appear above the top of the valence band. These states tend to be delocalized and to mix with the valence band as the nitrogen concentration is increased. The optical absorption in the range between 400 and 700 nm is enhanced by the substitutional N impurities. The eect of interstitial N on the electronic and the optical properties of TiO2 depends on the interaction between the nitrogen dopants and the surrounding oxygen. The bonding between N and O introduces a series of localized occupied states under and above the upper valence band, and the electron transitions from these states improve the visible-light absorption of TiO2.

Anti-Inflammatory Effects of Naringin in Chronic Pulmonary Neutrophilic Inflammation in Cigarette Smoke-Exposed Rats

Yi-Chu Nie,Hao Wu,Pei-Bo Li,Yu-Long Luo,Kang Long,Li-Ming Xie,Jian-Gang Shen,Wei-Wei Su 한국식품영양과학회 2012 Journal of medicinal food Vol.15 No.10

Naringin, a well-known flavanone glycoside of grapefruit and citrus fruits, was found to be as an effective anti-inflammatory compound in our previous lipopolysaccharide-induced acute lung injury mouse model via blockading activity of nuclear factor κB. The current study sought to explore the anti-inflammatory effects of naringin on chronic pulmonary neutrophilic inflammation in cigarette smoke (CS)-induced rats. Seventy Sprague-Dawley rats were randomly divided into seven groups to study the effects of CS with or without various concentrations of naringin or saline for 8 weeks. The results revealed that naringin supplementation at 20, 40, and 80 mg/kg significantly increased body weight of CS-induced rats as compared to that in the CS group. Moreover, naringin of 20, 40, and 80 mg/kg prevented CS-induced infiltration of neutrophils and activation of myeloperoxidase and matrix metalloproteinase-9, in parallel with suppression of the release of cytokines, such as tumor necrosis factor-α and interleukin-8 (IL-8). IL-10 in bronchoalveolar lavage fluid was significantly suppressed after CS exposure, but dose dependently elevated by naringin. The results from hematoxylin and eosin staining revealed that naringin dose dependently reduced CS-induced infiltration of inflammatory cells, thickening of the bronchial wall, and expansion of average alveolar airspace. In conclusion, our data suggest that naringin is an effective anti-inflammatory compound for attenuating chronic pulmonary neutrophilic inflammation in CS-induced rats.

Serum Macrophage Migration Inhibitory Factor as a Biomarker of Active Pulmonary Tuberculosis

Zhong-bo Shang,Jun Wang,Shou-gang Kuai,Yin-yin Zhang,Qin-fang Ou,Hao Pei,Li Hua Huang 대한진단검사의학회 2018 Annals of Laboratory Medicine Vol.38 No.1

Background: Macrophage migration inhibitory factor (MIF), a pro-inflammatory cytokine with chemokine-like functions, has been shown to play a central role in several acute and chronic inflammatory diseases. However, limited information is available regarding the use of MIF as an inflammatory pathway marker in patients with tuberculosis. This study aimed to investigate the association of MIF with IFN-γ and TNF-α in active pulmonary tuberculosis (APTB) following anti-tuberculosis treatment. Methods: The MIF, TNF-α, and IFN-γ serum levels were determined in 47 patients with APTB by cytokine-specific ELISA at four phases: prior to anti-tuberculosis drug treatment (baseline), and following 2, 4, and 6 months of treatment. In addition, we measured the MIF, TNF-α, and IFN-γ serum levels in 50 health controls. Results: MIF serum levels were significantly elevated (P<0.05) in patients with APTB prior to treatment compared with that in control subjects, and TNF-α ≥449.7 pg/mL was associated with high MIF levels (≥13.1 ng/mL). MIF levels were significantly reduced (P<0.01) following 2, 4, and 6 months of treatment, with variations in TNF-α and IFN-γ serum levels. MIF levels were positively correlated with the paired TNF-α level at baseline (r=0.1103, P=0.0316) and following 6 months of treatment (r=0.09569, P=0.0364).Conclusions: A reduction in the MIF serum levels in patients with APTB following anti-tuberculosis treatment may positively affect host immune protection against Mycobacterium tuberculosis infection. Thus, serum MIF levels may constitute a useful marker for assessing therapy effectiveness in patients with APTB.