Evolution of the effect of sulfur confinement in graphene-based porous carbons for use in Li-S batteries

Jia, Xiangling,Zhang, Chen,Liu, Juanjuan,Lv, Wei,Wang, Da-Wei,Tao, Ying,Li, Zhengjie,Zheng, Xiaoyu,Yu, Jong-Sung,Yang, Quan-Hong The Royal Society of Chemistry 2016 Nanoscale Vol.8 No.8

<P>A controllable drying strategy is proposed for the precise and non-destructive control over the structure of a 3D graphene assembly. Such an assembly is used as a model carbon material to investigate the pore structure-dependent shuttle effect and cycling performance of the cathode of a Li-S battery.</P>

Uncertainty quantifi cation of the power control system of a small PWR with coolant temperature perturbation

Xiaoyu Li,Chuhao Li,Yang Hu,Yongqi Yu,Wenjie Zeng,Haibiao Wu 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.6

The coolant temperature feedback coefficient is an important parameter of reactor core power controlsystem. To study the coolant temperature feedback coefficient influence on the core power controlsystem of small PWR, the core power control system is built with the nonlinear model and fuzzy controltheory. Then, the uncertainty quantification method of reactor core parameters is established based onthe Latin hypercube sampling method and the Bootstrap method. Finally, under the conditions ofreactivity step perturbation and coolant inlet temperature step perturbation, uncertainty analysis for twocases is carried out. The result shows that with fuzzy controller and fuzzy PID controller, the uncertaintyof the coolant temperature feedback coefficient affects the core power control system, and the maximumuncertainties of core relative power, coolant temperature deviation, fuel temperature deviation and totalreactivity are acceptable

Effect of Sn on Plastic Deformation Ability of Fe–Si–B–P–Sn bulk Metallic Glasses

Xiaoyu Wu,Xining Li,Xue Li,Shengli Li 대한금속·재료학회 2023 METALS AND MATERIALS International Vol.29 No.12

Fe-based bulk metallic glasses have the advantages of high strength and low coercivity. However, their plastic deformationability is negligible. Therefore, in this study, Sn was added to a Fe–Si–B–P bulk metallic glass matrix to study its influence onthe formation and plastic deformation ability of Fe–Si–B–P bulk metallic glasses. The results showed that the mixing enthalpyof Sn was less than that of Fe and other metal-like atoms, which caused Sn atoms to separate from Si-, B- and P-centeredclusters, resulting in metal-like clusters not occupying adjacent positions and the voids between clusters being occupied bySn atoms. With increasing Sn, the metal-metal bonds of the linked clusters increased and the macroscopic performance wasmanifested in an improvement in the plastic deformation ability. With 0.3 at% Sn addition, the alloy system showed the bestplastic deformation ability increasing from 0.7 to 2.2% and the yield strength of 3150 MPa.

Ozone infusiblization and curing mechanism of polysilazane ceramic precursor fibers

Li Xiaohong,Luo Xiaoyu,Li Jing,Li Jinxia,Yang Jiahao,Ahmad Zahoor,Bao Zhihao,Zhang Xiao,Chen Jianjun 한국세라믹학회 2023 한국세라믹학회지 Vol.60 No.5

An appropriate infusible method plays a vital role as one of the key processes of the fabrication of polymer-derived ceramic fibers. In this work, ozone curing, a novel room temperature controllable curing strategy was used to prepare SiCN ceramic fibers. Some circular pores were observed on the surface of the obtained SiCN ceramic fibers. The tensile strength of the fibers was also investigated. To reveal the ozone-curing mechanisms of the PSZ fibers and the formation process of the circular pores, the FT-IR, SEM, OM, XRD and TG were characterized. The results showed that the Si–H bonds and Si-CH3 groups in the PSZ molecule were oxidized gradually to form oxygen-containing groups such as Si–OH, Si–O-Si and C = O in the ozone curing process, which contributed to the curing and weight gain of the PSZ fibers. Moreover, a hydrolysis reaction between Si-NH-Si and H2O might further accelerate the curing of the PSZ fibers. An unexpected result of the hydrolysis reaction is the formation of some circular pores on the surface layer of the PSZ fibers. This strategy provides a method to design, adjust and control the microstructure and composition of silicon-based ceramic fibers, and the obtained SiCN fibers may be used as catalyst support, bacterial culture and other fields.

Effect of Paecilomyces cateniannulatus on the adsorption of nickel onto graphene oxide

Xiaoyu Li,Fengbo Li,Lejin Fang 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.12

Graphene oxide (GO) was synthesized by chemical oxidation method and used to remove nickel (Ni(II)) from aqueous solutions in the presence of Paecilomyces cateniannulatus (P. cateniannulatus). Based on characteristic results, it was demonstrated that P. cateniannulatus was easily combined with carboxyl groups of GO by covalent bond. The adsorption results showed that P. cateniannulatus facilitated the adsorption of Ni(II) on GO over a wide range of pH. The maximum adsorption capacities of GO+P. cateniannulatus and GO calculated from Langmuir model at pH 4.0 and T=303 K were 104.2 and 81.3mg·g−1, respectively. According to the analysis of thermodynamic parameters, the adsorption of Ni(II) on GO+P. cateniannulatus was endothermic and spontaneous. The highlight of this study quantitatively assessed the effect of bacteria on the fate and transports of heavy metals in near-surface geologic systems.

MECHANOCHEMICAL SYNTHESIS OF NiO NANOPARTICLES: INSIGHT INTO THE NATURE OF PREFERRED GROWTH ORIENTATION

XIAOYU LI,HUAMING YANG,LIANGJIE FU,TIANCHENG LIU 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2014 NANO Vol.9 No.4

Nickel oxide (NiO) nanoparticles were synthesized by calcination at 400?C to 700?C for 8 h of theprecursor obtained via mechanochemical reaction of Ni(NO 3 ) 2 ? 6 H 2 O with citric acid as a dis-persant. The nanoparticles were characterized by thermogravimetric-diferential scanningcalorimetry (TG-DSC), X-ray difraction (XRD) and transmission electron microscopy (TEM). The kinetics of diferent surfaces of the nanocrystals under nonisothermal conditions wasinvestigated. The activation energies for diferent lattice planes of NiO nanoparticles weredetermined using the Arrhenius equation, revealing their preferred orientation. The growth ofNiO obeyed the general theory that nanoparticles with the largest surface energy tend to form. XRD data reveal that the NiO nanoparticles possess preferred (111) or (200) orientations thatre°ect their complex activity. The nature of preferred growth orientation was found to benegative difusion activity among diferent lattice surfaces, which indicates that oxygen atomsdi®use from low oxygen concentration on the lattice surface to high concentration on the latticesurface.

Effect of Red Pepper (Capsicum frutescens) Powder or Red Pepper Pigment on the Performance and Egg Yolk Color of Laying Hens

Li, Huaqiang,Jin, Liji,Wu, Feifei,Thacker, Philip,Li, Xiaoyu,You, Jiansong,Wang, Xiaoyan,Liu, Sizhao,Li, Shuying,Xu, Yongping Asian Australasian Association of Animal Productio 2012 Animal Bioscience Vol.25 No.11

Two experiments were conducted to study the effects of red pepper (Capsicum frutescens) powder or red pepper pigment on the performance and egg yolk color of laying hens. In Exp. 1, 210, thirty-wk old, Hy-line Brown laying hens were fed one of seven diets containing 0.3, 0.6, 1.2, 2.0, 4.8 or 9.6 ppm red pepper pigment or 0.3 ppm carophyll red. Each diet was fed to three replicate batteries of hens with each battery consisting of a row of five cages of hens with two hens per cage (n = 3). In Exp. 2, 180, thirty-wk old, Hyline Brown laying hens, housed similarly to those in Exp. 1, were fed an unsupplemented basal diet as well as treatments in which the basal diet was supplemented with 0.8% red pepper powder processed in a laboratory blender to an average particle size of $300{\mu}m$, 0.8% red pepper powder processed as a super fine powder with a vibrational mill ($44{\mu}m$) and finally 0.8% red pepper powder processed as a super fine powder with a vibrational mill but mixed with 5% $Na_2CO_3$ either before or after grinding. A diet supplemented with 0.3 ppm carophyll red pigment was also included (n = 3). In both experiments, hens were fed the red pepper powder or pigment for 14 days. After feeding of the powder or pigment was terminated, all hens were fed the basal diet for eight more days to determine if the dietary treatments had any residual effects. In Exp. 1, there were no differences in egg-laying performance, feed consumption or feed conversion ratio due to inclusion of red pepper pigment in the diet. Average egg weight was higher (p<0.05) for birds fed 1.2, 2.4 or 9.6 ppm red pepper pigment than for birds fed the diet containing 0.3 ppm red pepper pigment. On d 14, egg color scores increased linearly as the level of red pepper pigment in the diet increased. In Exp. 2, feeding red pepper powder did not affect egg-laying performance, feed consumption or feed conversion ratio (p>0.05). However, compared with the control group, supplementation with all of the red pepper powder treatments increased egg weight (p<0.05). All the red pepper powder treatments also increased (p<0.05) the yolk color score compared with the control. The results of the present study suggest that both red pepper powder and pigment are effective feed additives for improving egg yolk color for laying hens.

D-stability of generalized homogeneous cooperative time-varying systems

Xiaoyu Li,Yuangong Sun 제어로봇시스템학회 2023 제어로봇시스템학회 국제학술대회 논문집 Vol.2023 No.10

The preliminary study of exosomes derived from thymosin beta 4-treated adipose-derived stem cells in fat grafting

Li Wandi,Yang Yan,Zhang Xiaoyu,Lin Yan,Li Haoran,Yao Yu,Mu Dali 한국유전학회 2023 Genes & Genomics Vol.45 No.4

Background The retention rate in autologous fat grafting is an increasing concern for surgeons and patients. Our previous research verified that thymosin beta 4 (Tβ4) positively affected fat survival, while the mechanism was unknown. The endothelial cells (ECs) and exosomes derived from adipose-derived stem cells (ADSCs) were regarded to play a critical role in fat transplantation. Objective This study aimed to evaluate the effect of exosomes derived from Tβ4-treated ADSCs on EC proliferation and to identify the exosomal microRNA (miRNA) profile compared with the Tβ4-untreated group. Additionally, this research intended to recognize the related molecules and signaling pathways in the Tβ4-treated group with potential roles in fat transplants. Methods ADSCs were collected from patients who underwent liposuction surgery. Depending on whether the medium was supplemented with exogenous Tβ4 or not, exosomes derived from cultured ADSCs were divided into the Tβ4-Exos group and Con-Exos group. Exosome uptake and cell counting kit-8 (CCK-8) assays assessed the influence of Tβ4-Exos on EC proliferation. The exosomal miRNAs of the two groups were analyzed by next-generation sequencing. With the criteria at the |log2 (fold change)| ≥ 1 and p-value < 0.05, up-regulated and down-regulated differentially expressed miRNAs (DEMs) were obtained. Prediction databases were used to predict the downstream mRNAs for DEMs. And then, overlapping genes for the up-regulated DEMs and the down-regulated were screened out, followed by enrichment analysis, protein–protein interaction network construction, and the gene cluster and hub gene identification. Results ADSCs were obtained from four female patients. The exosome uptake and CCK-8 assays showed that the Tβ4-Exos could increase cell growth rate compared with the control group (DMEM-H + PBS). In Tβ4-Exos and Con-Exos groups, 2651 exosomal miRNAs were recognized, with 80 up-regulated and 99 down-regulated DEMs according to the criteria. After the prediction, 621 overlapping genes for the up-regulated and 572 for the down-regulated DEMs were screened. The subsequent bioinformatics analysis found specific molecules and pathways related to the positive effect on fat survival. Conclusions The exosomes derived from Tβ4-treated ADSCs probably positively affect EC proliferation. Compared with the Con-Exos group, several exosomal DEMs, genes, and pathways were distinguished. These findings of this exploratory study provide the potential direction for future in-depth research on fat grafting.

Dynamic Event-triggered Control for Heterogeneous Leader-following Consensus of Multi-agent Systems Based on Input-to-state Stability

Xiaoyu Li,Dazhong Ma,Xuguang Hu,Qiuye Sun 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.2

By utilizing dynamic event-triggered control strategy, this paper deals with consensus problem of a class of heterogeneous leader-following multi-agent systems(MASs) consisting of a high-dimensional leader system but low-dimensional following systems. A kind of observer-based consensus controllers is put forward with a dynamic event-triggered function consisting of the measurement error and a threshold based on the neighbors’ discrete states to reduce unnecessary utilization of limited communication and computation resources. Meanwhile, a dynamic variable is used to generate the event-triggered law using Input-to-State Stability(ISS) criteria. Based on this criteria, the proposed control strategy ensures stability of MASs, which fully reflects of the relationship between the external control inputs of the following systems and the internal states of the leader system and fully considered the influence of disturbances or noises on the MASs. Furthermore, the Zeno behavior for triggering time sequence is excluded. At last, a numerical simulation is provided to demonstrate the feasibility and effectiveness of the theoretical results.