O₂ Adsorption and Dissociation on A Hydrogenated Anatase (101) Surface

Liu, Liangliang,Liu, Qin,Zheng, Yongping,Wang, Zhu,Pan, Chunxu,Xiao, Wei American Chemical Society 2014 The Journal of Physical Chemistry Part C Vol.118 No.7

<P>O<SUB>2</SUB> adsorption and dissociation on a hydrogenated anatase (101) surface are studied with first-principle calculations coupled with the nudged elastic band (NEB) method. H atoms on the anatase (101) surface or at subsurface sites can increase the absolute values of the O<SUB>2</SUB> adsorption energy. The O<SUB>2</SUB> dissociation barriers on an anatase surface with two H atoms at the subsurface sites or with a H surface adatom and a subsurface atom are much lower than that of the dissociation on a surface with H adatoms on the (101) surface. After the dissociation, OH, H<SUB>2</SUB>O, and O adatoms may form on the surface. Because it is not difficult for H adatoms on the surface to diffuse to the subsurface sites, surface H doping atoms are very useful to reduce the O<SUB>2</SUB> dissociation barrier. The anatase particles with hydrogenated (101) surface are efficient catalysts to oxidize the adsorbed toxic gas molecule.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jpccck/2014/jpccck.2014.118.issue-7/jp408221x/production/images/medium/jp-2013-08221x_0025.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/jp408221x'>ACS Electronic Supporting Info</A></P>

Gamma correction FCM algorithm with conditional spatial information for image segmentation

( Yang Liu ),( Haipeng Chen ),( Xuanjing Shen ),( Yongping Huang ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.9

Fuzzy C-means (FCM) algorithm is a most usually technique for medical image segmentation. But conventional FCM fails to perform well enough on magnetic resonance imaging (MRI) data with the noise and intensity inhomogeneity (IIH). In the paper, we propose a Gamma correction conditional FCM algorithm with spatial information (GcsFCM) to solve this problem. Firstly, the pre-processing, Gamma correction, is introduced to enhance the details of images. Secondly, the spatial information is introduced to reduce the effect of noise. Then we introduce the effective neighborhood mechanism into the local space information to improve the robustness for the noise and inhomogeneity. And the mechanism describes the degree of participation in generating local membership values and building clusters. Finally, the adjustment mechanism and the spatial information are combined into the weighted membership function. Experimental results on four image volumes with noise and IIH indicate that the proposed GcsFCM algorithm is more effective and robust to noise and IIH than the FCM, sFCM and csFCM algorithms.

Identification and phylogeny of five male-specific lethal genes in the silkworm Bombyx mori

Wenbin LIU,Yong ZHANG,Xuexia MIAO,Yongping Huang 한국곤충학회 2008 Entomological Research Vol.38 No.-

In the fruit fly (Drosophila melanogaster) dosage compensation equalization of X-linked genes between the sexes is achieved via a complex that is termed the compensasome, which is composed of at least five male-specific lethal (msl) genes and two non-coding RNAs. In the present study, we cloned all five homologs (termed the msls) from the silkworm, Bombyx mori, in which the issue of dosage compensation remains controversial. Data mining and robust phylogenetic analysis revealed that msls are ubiquitously present in genomes, from insects to mammals, with unknown biological functions. However, the five genes seem to have evolved at different times due to gene duplication. Real-time reverse transcriptase-polymerase chain reaction experiments demonstrated that in the silkworm, some Z-linked genes are expressed at higher levels in females than in males while others are expressed at lower levels in females than in males, which suggests that the msl genes in the silkworm and fruit fly may have different roles. We discussed the relationship of phylogeny between msl and sex-lethal.

Glass fiber reinforced graphite/carbon black@PES composite films for high-temperature electric heaters

Yaning Liu,Zhen Xiao,Wenkui Zhang,Hui Huang,Jun Zhang,Yongping Gan,Xinping He,Bingjia Wang,Yi Han,Yang Xia 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.107 No.-

Carbon based conductive polymer composites as electrothermal materials offers many merits in highflexibility, light weight, low cost, excellent processability, and rapid heating ability, however, the maximumworking temperature is usually lower than 200 C, hampering seriously the medium–high temperatureapplications. Herein, a series of rationally designed glass fiber reinforced graphite/carbonblack@polyethersulfone (G/CB@PES) composites are developed to significantly promote the maximumworking temperature over 300 C. To be specific, the introduced glass fibers acted as rigid skeleton greatlyenhance the mechanical strength of PES polymer matrix, thereby offering robust structural stability inhigh temperature working scenario. Meanwhile, glass fibers not only endow G/CB@PES composite withexcellent flame-retardant ability, but also provide rapid thermal conduction channels to reduce the riskof heat accumulation and overheating. More importantly, glass fiber reinforced G/CB@PES composites aselectrothermal film heaters exhibit superior electric heating performance in terms of fast temperatureresponsiveness, high electric heating efficiency, stable maximum working temperatures, and high electricpower efficiency under the relatively low applied voltages of 3–21 V. This work provides new insights onthe innovative design and facile fabrication of high working temperature electrothermal film heaters inemerging applications.

Brief and accurate analytical approximations to nonlinear static response of curled cantilever micro beams

Youhong Sun,Yongping Yu,Baochang Liu 국제구조공학회 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.56 No.3

In this paper, the nonlinear static response of curled cantilever beam actuators subjected to the one-sided electrostatic field is focused on. By assuming the deflection function of electrostatically actuated beam, analytical approximate solutions are established via using Galerkin method to solve the equilibrium equation. The Pull-In voltages which determine the stability of the curled beam actuators are also obtained. These approximate solutions show excellent agreements with numerical solutions obtained by the shooting method and the experimental data for a wide range of beam length. Expressions of these analytical approximate solutions are brief and could easily be used to derive the effects of various physical parameters on MEMS structures.

A novel method for longitudinal modification and tooth contact analysis of non-circular cylindrical gears

Dawei Li,Yongping Liu,Jun Gong,Yongqiao Wei,Gang Zhao 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.12

The traditional geometry of non-circular cylindrical gears provides a contact line between tooth surfaces. In a misaligned non-circular cylindrical gear drive, causing edge contacts that result in noise and vibration. The point contact of the tooth surface is achieved by modification of the driving gear in the longitudinal direction, in order to reduce the sensitivity of tooth surface contact to installation errors. The proposed longitudinal modification method is based on the application of a grinding worm by controlling the center distance of non-circular cylindrical gear and worm. Based on the gear meshing principle, a mathematical model of the tooth surfaces of non-circular cylindrical gears is established, and a parametric tooth surface equation with a unified expression is obtained. Tooth contact analysis (TCA) of non-circular cylindrical gears shows that the contact path and contact area on the tooth surface are shifted with the change of installation error, but still distributed in the middle of the tooth surface without creating edge contact. The transmission error is increased with the growth of installation error. Tooth modification in a longitudinal direction has an obvious improvement effect on the bad tooth contact condition, but too large a tooth modification parameter will make the tooth surface load distribution concentrated in a smaller area, which results in the decrease of gear load capacity.

Protective efficacy of a novel multivalent vaccine in the prevention of diarrhea induced by enterotoxigenic Escherichia coli in a murine model

Hong Zhao,Yongping Xu,Gen Li,Xin Liu,Xiaoyu Li,Lili Wang 대한수의학회 2022 Journal of Veterinary Science Vol.23 No.1

Background: Enterotoxigenic Escherichia coli (ETEC) infection is a primary cause of livestock diarrhea. Therefore, effective vaccines are needed to reduce the incidence of ETEC infection. Objectives: Our study aimed to develop a multivalent ETEC vaccine targeting major virulence factors of ETEC, including enterotoxins and fimbriae. Methods: SLS (STa-LTB-STb) recombinant enterotoxin and fimbriae proteins (F4, F5, F6, F18, and F41) were prepared to develop a multivalent vaccine. A total of 65 mice were immunized subcutaneously by vaccines and phosphate-buffered saline (PBS). The levels of specific immunoglobulin G (IgG) and pro-inflammatory cytokines were determined at 0, 7, 14 and 21 days post-vaccination (dpv). A challenge test with a lethal dose of ETEC was performed, and the survival rate of the mice in each group was recorded. Feces and intestine washes were collected to measure the concentrations of secretory immunoglobulin A (sIgA). Results: Anti-SLS and anti-fimbriae-specific IgG in serums of antigen-vaccinated mice were significantly higher than those of the control group. Immunization with the SLS enterotoxin and multivalent vaccine increased interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) concentrations. Compared to diarrheal symptoms and 100% death of mice in the control group, mice inoculated with the multivalent vaccine showed an 80% survival rate without any symptom of diarrhea, while SLS and fimbriae vaccinated groups showed 60 and 70% survival rates, respectively. Conclusions: Both SLS and fimbriae proteins can serve as vaccine antigens, and the combination of these two antigens can elicit stronger immune responses. The results suggest that the multivalent vaccine can be successfully used for preventing ETEC in important livestock.

Spatial Distribution Patterns of Soil Salinity in the Heavy Salinization Zone at Different Scales in Yinchuan Plain

Anping Yun,Kelin Hu,Yongping Wei,Liming Liu,De Zhou 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Critical Role of Mullite-type Oxides’ Surface Chemistry on Catalytic NO Oxidation Performance

Thampy, Sampreetha,Ashburn, Nickolas,Dillon, Sean,Liu, Chengfa,Xiong, Ka,Mattson, Eric C.,Zheng, Yongping,Chabal, Yves J.,Cho, Kyeongjae,Hsu, Julia W. P. American Chemical Society 2019 The Journal of Physical Chemistry Part C Vol.123 No.9

<P>By combining low energy ion scattering spectroscopy and density functional theory calculation, we study the surface composition and surface formation energy of AMn<SUB>2</SUB>O<SUB>5</SUB> (A = Sm, Bi) mullite-type oxides synthesized by different methods and their effects on NO catalytic performance. It is well-known that hydrothermal (HT) synthesis at low temperatures produces materials with higher specific surface areas (SSAs) compared with those synthesized by coprecipitation (CP) and high-temperature calcination; however, it is less clear how synthesis methods affect surface chemistry. We find that the NO oxidation performance of SmMn<SUB>2</SUB>O<SUB>5</SUB>-HT does not match the SSA increase when compared to the lower SSA SmMn<SUB>2</SUB>O<SUB>5</SUB>-CP. Combined experimental and theoretical investigation reveals that SmMn<SUB>2</SUB>O<SUB>5</SUB>-HT includes a higher fraction of inactive Sm-terminated surfaces, which explains its lower than expected activity. However, the surface chemistry change depends strongly on the A-site element. The exposed surfaces of BiMn<SUB>2</SUB>O<SUB>5</SUB>-CP are predominantly terminated by Bi and exhibit a very low activity, while BiMn<SUB>2</SUB>O<SUB>5</SUB>-HT contains active Mn-terminated surfaces. This study shows that catalytic performance is determined predominantly by surface chemistry, which depends critically on the A-site element and synthesis method and less by physical surface area.</P> [FIG OMISSION]</BR>

Efficient buffeting analysis under non-stationary winds and application to a mountain bridge

Yanwen Su,Guoqing Huang,Ruili Liu,Yongping Zeng 한국풍공학회 2021 Wind and Structures, An International Journal (WAS Vol.32 No.2

Non-synoptic winds generated by tornadoes, downbursts or gust fronts exhibit significant non-stationarity and can cause significant wind load effect on flexible structures such as long-span bridges. However, conventional assumptions on stationarity used to evaluate the structural wind-induced vibration are inadequate. In this paper, an efficient frequency domain scheme based on fast CQC method, which can predict non-stationary buffeting random responses of long-span bridges, is presented, and then this approach is applied to evaluate the buffeting response of a long-span suspension bridge located in a complex mountainous wind environment as an example. In this study, the data-driven method based on one available measured wind speed sample is firstly presented to establish non-stationary wind models, including time-varying mean wind speed, time-varying intensity envelope function and uniformly modulated fluctuating spectrum. Then, a linear time-variant (LTV) system based on the proposed scheme can be generally applied to calculate the non-stationary buffeting responses. The effectiveness and accuracy of the proposed scheme are verified through Monte Carlo time domain simulation implemented in ANSYS platform. Also, the transient effect nature of the bridge responses is further illustrated by comparison of the non-stationary, quasi-stationary and steady-state cases. Finally, buffeting response analysis with traditional stationary treatment (10 min constant mean plus stationary wind fluctuation) is performed to illustrate the importance of the non-stationary characteristics embedded in original wind speed samples.