Bipartite Consensus of Nonlinear Discrete-time Multi-agent Systems via Variable Impulsive Control

Ziqiang Xu,Yun Li,Xiang Hu,Chuandong Li,Yiyan Han 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.2

This paper addresses the bipartite consensus of the nonlinear discrete-time multi-agent systems on network where cooperation and confrontation exist simultaneously. The communication graph has negative weights to represent antagonistic interaction among agents. Two kinds of distributed variable impulsive protocols are designed for case with leader and leaderless. Compared with existing fixed-time impulsive protocols, the action instant of variable impulsive protocol is in a time window and not fixed, which is more suitable for practical application. By employing Lyapunov function approach and comparison system theorem, the results reveal that the bipartite leaderless consensus and bipartite tracking consensus can be achieved. Meanwhile, the rate of bipartite consensus possess the characteristic of exponential, if some conditions are met. Finally, the effectiveness of the consensus analysis is verified by three simulation examples.

Effects of Different Atmosphere on Electrochemical Performance of Hard Carbon Electrode in Sodium Ion Battery

Ziqiang Xu,Jinchen Chen,Mengqiang Wu,Cheng Chen,Yaochen Song,Yuesheng Wang 대한금속·재료학회 2019 ELECTRONIC MATERIALS LETTERS Vol.15 No.4

Hard carbon is deemed to be a most promising anode materials for sodium—ion batteries (SIBs), while, the issues of lowcapacity and low initial coulombic efficiency still exist limiting the development of SIBs. Although high temperature carbonizationof biomass materials under nitrogen or argon atmosphere is a common method for preparation of hard carbon,there are few reports about the effects of different protective atmospheres on propriety of hard carbon. In this article, hornet’snest (HN) is used to prepare hard carbon under nitrogen and argon. At a suitable carbonization temperature (1200 °C and1400 °C), the hard carbon under argon possesses lower specific surface area (25–50 cm−3 g−1), but higher initial coulombefficiency (4–6%) and higher capacity retention (3–6%). Thus, it is inferred that high—performance hard carbon can beobtained under argon atmosphere. Our research about the effect of sintering atmosphere on material properties is expectedto provide a reference for the synthetization of hard carbon by high temperature carbonization.

Tunnel Bottom Cavity Laws of Heavy-Haul Railway Tunnel under Train Load and Groundwater in Weak Surrounding Rock Condition

Ziqiang Li,Zheng Li,Weiwei Huang,Zhifan Xu,Wengang Zhang,Kunping Chen 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.3

This work aimed to study the cavity mechanism of surrounding rock at the bottom of a tunnel under the combined action of heavy-haul train load and groundwater. The study location was the Taihangshan Mountain Tunnel in Wari Railway, which is the first tunnel in China, constructed according to the 30 tons heavy-haul railway standards. Based on the water and soil pressure data measured in previous, the surrounding rock deterioration range and depth at the bottom of the heavy-haul railway tunnel under different axle loads and surrounding rock conditions were analysed by using a combination of laboratory test and discrete element method. The results showed objective defects in the bottom surrounding rock that appeared after the construction was completed, which provided a channel for groundwater. The groundwater flushed the surrounding rock at the bottom of the heavy-haul tunnels as time passed, and the dynamic action of heavy-haul trains caused the surrounding rock particles to gradually become loose, which was especially noticeable for the defect location in the weak surrounding rock. An increase in the axle load and a deterioration in the surrounding rock condition could aggravate the tunnel bottom cavity. The findings can be used to generate ideas for defects prediction and treatment methods for heavy-haul railway tunnels.

Volatilization of Na and B During Vitrification of HLW and Associated Effects on Crystallization

Kai Xu,Ziqiang Jia,Ruidong Jia 한국방사성폐기물학회 2023 한국방사성폐기물학회 학술논문요약집 Vol.21 No.1

During nuclear waste vitrification, loss of sodium (Na) and boron (B) occurs, as these elements are highly volatile at high temperatures, which causes fluctuations in composition and consequently affects the properties of the glass products. In this study, we investigated the volatilization behaviors of Na and B from a simulated high-level waste glass as functions of heating temperature and dwelling duration. Based on the data obtained regarding the composition of Na and B and the structure of the glass, a hypothetical model was proposed to explain the volatilization behaviors of Na and B from a structural viewpoint. As the loss of Na and B during vitrification, the crystallization of the glass occurred. Thus, the crystallization behavior of the simulated waste glass upon composition deviation was studied.

Successful New Inhibitive Water-Based Fluid Application, Sulige Gas Field, China

Ming Zhang,Tiantai Li,Ziqiang Xu,Da Li 보안공학연구지원센터 2016 International Journal of u- and e- Service, Scienc Vol.9 No.9

This study developed a new type of shale drilling anti-collapse inhibitor and compounded a set of stable shale water-based drilling fluid for horizontal wells to effectively solve hole shrinkage, collapse, tool sticking, and other complex downhole problems involved in the shale drilling at the horizontal section of the Sulige gas field. Laboratory experimental evaluations indicated that this system had a strong inhibitory effect on shale formation and sound compatibility. After its weight reached 1.20g/cm3, the system exhibited a stable rheology, lubricity, filter loss, high recovery rate of rock debris, and low formation damage. The mud cake was smooth, thin, tough, and compact. The drilling fluid also maintained suitable anti-collapse capability, lubricity, rheology, and highly efficient debris-carrying and well-flushing ability in its field application in the drilling of the shale section of the Sulige gas field. The tripping operation exhibited no clear resistance and sticking. This system achieved significant effects and satisfied the requirements of the drilling construction of a horizontal well in the Sulige gas field.

Embedding Cobalt Into ZIF-67 to Obtain Cobalt-Nanoporous Carbon Composites as Electrode Materials for Lithium ion Battery

Zheng, Guoxu,Yin, Jinghua,Guo, Ziqiang,Tian, Shiyi,Yang, Xu The Korean Electrochemical Society 2021 Journal of electrochemical science and technology Vol.12 No.4

Lithium ion batteries (LIBs) is a kind of rechargeable secondary battery, developed from lithium battery, lithium ions move between the positive and negative electrodes to realize the charging and discharging of external circuits. Zeolitic imidazolate frameworks (ZIFs) are porous crystalline materials in which organic imidazole esters are cross-linked to transition metals to form a framework structure. In this article, ZIF-67 is used as a sacrificial template to prepare nano porous carbon (NPC) coated cobalt nanoparticles. The final product Co/NPC composites with complete structure, regular morphology and uniform size were obtained by this method. The conductive network of cobalt and nitrogen doped carbon can shorten the lithium ion transport path and present high conductivity. In addition, amorphous carbon has more pores that can be fully in contact with the electrolyte during charging and discharging. At the same time, it also reduces the volume expansion during the cycle and slows down the rate of capacity attenuation caused by structure collapse. Co/NPC composites first discharge specific capacity up to 3115 mA h/g, under the current density of 200 mA/g, circular 200 reversible capacity as high as 751.1 mA h/g, and the excellent rate and resistance performance. The experimental results show that the Co/NPC composite material improves the electrical conductivity and electrochemical properties of the electrode. The cobalt based ZIF-67 as the precursor has opened the way for the design of highly performance electrodes for energy storage and electrochemical catalysis.

Environmental Friendly Intumescent Flame Retardant Gives Epoxy Resin Excellent Fire Resistance and Mechanical Properties

Huan Wang,Li Li,Yan Kang,Xue Yin,Xuedi Lei,Jing Yang,Hui Xi,Xueqing Xu,Zhiwang Yang,Ziqiang Lei 한국고분자학회 2022 Macromolecular Research Vol.30 No.8

To reduce the fire hazard of epoxy resin (EP), PA-CS-M (where PA = phytic acid, CS =c hitosan, M=Cu2+, Co2+, Al3+, Zn2+, Mn2+) environmental friendly flame retardant is prepared by a simple and green method. By comparing the data after cone calorimetry test (CCT) of various composites, it is found that when 5 wt% PA-CS-Mn is added to EP, it has good flame retardant and smoke suppression performance. The peak heat release rate (pk-HRR) decreased by 38% and the smoke production rate (SPR) decreased by 33%. In addition, some toxic smoke such as CO has been significantly inhibited. The structures and morphologies of the materials were investigated by Fourier transform infrared (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). When combined with expandable graphite (EG), it is found that when the ratio of PA-CS-Mn to EG is 1:5, the pk-HRR value and SPR value decreased by 69.8% and 66.6%, respectively. More importantly, the mechanical properties of the EP composites have also been greatly improved. The flexural modulus reaches 5.04 GPa, which is 52.3% higher than pure EP, and the flexural strength increases to 79.4 MPa, which also shows an increase of 41.4% as to the matrix.

The role of CTNNB1 and LEF1 in feather follicles development of Anser cygnoides and Anser anser

Yue Sun,Yuxuan Zhou,Petunia Msuthwana,Jing Liu,Chang Liu,Cornelius Tlotliso Sello,Yupu Song,Ziqiang Feng,Shengyi Li,Wei Yang,Yunpeng Xu,Xiaomin Yan,Chuanghang Li,Yujian Sui,Jingtao Hu,Yongfeng Sun 한국유전학회 2020 Genes & Genomics Vol.42 No.7

Background Wingless-types/beta-catenin (Wnt/β-catenin) signaling pathway is one of the most extensively studied transcriptional cascades involved in various types of organogenesis including embryonic and postnatal development. Downy feather quantity is primarily affected by follicular development and gene regulations. Objective This research was aimed to investigate the role of catenin beta-1(CTNNB1) and lymphoid enhancerbinding factor-1 (LEF1) on feather follicles development at different developmental stages. Methods Fluorescence quantitative PCR, Western-blot and immunohistochemical methods were used in Anser cygnoides and Anser anser embryos (E12, E13 E18, and E28) and after birth gosling stages (G18, G48, G88) for gene expression analysis. Results CTNNB1 and LEF1 genes were expressed in Anser cygnoides and Anser anser at different embryonic and after-birth gosling developmental stages and the expression levels were significantly different in different stages (p < 0.05). The mRNA expression of CTNNB1 and LEF1 genes reached the highest level at D88 in Anser cygnoides, while the highest expression levels were at D18 and D88 in Anser anser, and the expression levels of CTNNB1 genes at D88 in all embryonic stages were significantly lower than after-birth stages. CTNNB1 and LEF1 protein expression were the highest at E12 and E28 for Anser cygnoides feather follicles development. While at a similar stage for Anser anser, the expression of CTNNB1 and LEF1 protein was the highest at D48 and D18. Protein expression at embryonic stages was in the epidermis (E) and the hair basal plate (P), the expression site for after-birth stages was in the dermal papilla (DP). Conclusion Our study illustrated that CTNNB1 and LEF1 has an impact on Anser cygnoides and Anser anser feather follicles growth and development.

Synthesis of Phosphorous Phenanthrene/L-Tryptophan Flame Retardant for Enhanced Flame Retardancy of Epoxy Resins

Li Li,Fenglin Hua,Hui Xi,Jing Yang,Ting Xiao,Rui Zuo,Xueqing Xu,Zhiwang Yang,Ziqiang Lei 한국고분자학회 2022 Macromolecular Research Vol.30 No.12

A new type of phosphorus-containing intrinsic flame retardant was prepared with L-tryptophan (L-Trp) and 9,10-dihydro-9-oxa-10-phosphorbenzophenanthrene- 10-oxide (DOPO) as the main components. The Schiff base from the reaction of 1,4-terephthalaldehyde and L-tryptophan provides active sites, and then the phosphorous compound, DOPO, is successfully introduced into the Schiff base to synthesize L-Trp-DOPO flame retardant. The intrinsic flame retardant property of LTrp- DOPO comes from the reaction of carbonyl groups and the epoxy groups in epoxy resin (EP) matrix. The prepared L-Trp-DOPO flame retardant can efficiently improve the flame retardancy and smoke suppression of the base material of EP. Cone calorimetric test (CCT) of EP/L-Trp-DOPO composite material was carried out. The data showed that the peak heat release rate (pk-HRR) value was reduced by 50.8% (from 1459 kW/m2 to 717 kW/m2), the THR value reduced by 78.3%, and the limiting oxygen index (LOI) value was increased by 24%. The addition of new flame retardant greatly reduced the release of toxic CO gas. The flame retardant mechanism was explored, and it can be found that after thermal decomposition of L-Trp- DOPO a dense carbon layer can be produced to isolate the fire source. In addition, during the combustion process, L-Trp-DOPO will produce phosphorus-containing free radicals which will quench the active free radicals in the gas phase and dilute the combustible gas. The prepared L-Trp-DOPO flame retardant has a flame retardant effect in both the condensed phase and the gas phase during the combustion process.