Dispersion of carbon nanotubes in aluminum improves radiation resistance

So, Kang Pyo,Chen, Di,Kushima, Akihiro,Li, Mingda,Kim, Sangtae,Yang, Yang,Wang, Ziqiang,Park, Jong Gil,Lee, Young Hee,Gonzalez, Rafael I.,Kiwi, Miguel,Bringa, Eduardo M.,Shao, Lin,Li, Ju unknown 2016 Nano energy Vol.22 No.-

<P><B>Abstract</B></P> <P>We can mass-produce metal/carbon nanotube (CNT) composites that show improved radiation tolerance. The 0.5wt% Al+CNT composite showed improved tensile strength without reduction of tensile ductility before radiation, and reduced void/pore generation and radiation embrittlement at high displacements per atom (DPA). Under helium ion irradiation up to 72DPA, the 1D carbon nanostructures survive, while sp<SUP>2</SUP> bonded graphene transforms to sp<SUP>3</SUP> tetrahedral amorphous carbon. Self-ion (Al) irradiation converts CNTs to a metastable form of Al<SUB>4</SUB>C<SUB>3</SUB>, but still as slender 1D nanorods with prolific internal interfaces that catalyze recombination of radiation defects, reducing radiation hardening and porosity generation. The 1D fillers may also form percolating paths of “nano-chimneys” that outgas the accumulated helium and other fission gases, providing an essential solution to the gas accumulation problem.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Dispersion of CNTs showed improved tensile strength without reduction of ductility. </LI> <LI> CNTs in Al reduced void/pore generation and radiation embrittlement at high DPA. </LI> <LI> Under He ion irradiation, 1D CNTs survive, while sp<SUP>2</SUP> bond transform to sp<SUP>3</SUP> carbon. </LI> <LI> Formation of metastable 1D Al<SUB>4</SUB>C<SUB>3</SUB> from CNTs still recombine radiation defects. </LI> <LI> This nanocomposite can help improve bulk properties for nuclear applications. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

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.

Fabrication of diarylide yellow pigments/modified SiO2 core–shell hybrid composite particles for electrophoretic displays

Ziqiang Wen,Yaqing Feng,Xianggao Li,Xiaoxu Li,Yu Bai,Qingmeng Tang,Yidan Gao 한국물리학회 2012 Current Applied Physics Vol.12 No.1

Diarylide yellow pigments/modified SiO2 coreeshell hybrid composite particles were fabricated via a newly developed two-step procedure. The surface of diarylide yellow pigments was coated with SiO2by the hydrolysis of Na2SiO3. The obtained particles were then modified with in situ generated 3-aminopropylsilanetriol or succinic acid to form composite particles containing amino or carboxyl groups. The FT-IR spectra, TGA and TEM showed that the particles had a coreeshell structure, the SEM suggested that the surface morphology of the composite particles was smooth, and the XPS and zeta potential measurement indicated that the composite particles had a high charge load. The obtained composite particles have been applied as electrophoretic particles in the electronic paper, which demonstrated that the newly developed procedure is an effective way to produce various organic/inorganic composite particles used for electrophoretic displays.

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.

Flame Retardancy of Epoxy Resin Improved by Graphene Hybrid Containing Phosphorous, Boron, Nitrogen and Silicon Elements

Li Li,Huan Wang,Fenglin Hua,Mingming Wang,Yuanshuo Zhang,Hui Xi,Jing Yang,Zhiwang Yang,Ziqiang Lei 한국고분자학회 2021 Macromolecular Research Vol.29 No.9

An effective ternary organic-inorganic composite flame retardant of reduced graphene oxide-poly-dopamine@graphitic carbon nitride@10-(2,5-dihydroxyphenyl)- 10-H-9-oxa-10-phosphaphenanthrene-10-oxide (RGO-PDA@g-C3N4@ODOPB) was successfully fabricated by co-precipitation method. Its property concerning the intrinsic flame retardancy and the mechanical performance was well studied when it was used as co-additives in combination with ammonium polyphosphate (APP) in epoxy resin (EP) samples. The surface morphology and the structure of RGO-PDA@g-C3N4 @ODOPB were characterized by SEM, and the molecular structure and compositions were investigated by FT-IR, powder XRD and 1H NMR. TGA, limit oxygen index (LOI), vertical burning test (UL-94), cone calorimeter test, and SEM were also used to investigate the thermal properties and flame retardancy of materials. As expected, the flame retardancy of EP was significantly heightened after adding of RGOPDA@ g-C3N4@ODOPB composites. It showed that with the 20% adding of RGO-PDA@g-C3N4@ODOPB/APP into EP led to the decreasing of the peak heat release rate and the total heat release at 78% and 62.5%, respectively. Meanwhile, the LOI value of the EP composites was as high as 29% and reached UL-94 V-0 rate. It was deemed that the excellent flame retardancy was attributed to the forming of compact and stable carbon layer, which was being catalytic carbonization by APP existed in the RGO-PDA@g-C3N4@ODOPB/APP composites. At the same time, the non-combustible gas released from thermal cracking of g-C3N4 during the combustion also benefited the flame retardant performance of EP.

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.

Capillarity-Driven Self-Assembly of Silver Nanowires-Coated Fibers for Flexible and Stretchable Conductor

Yi Li,Jun Chen,Xiao Han,Yinghui Li,Ziqiang Zhang,Yanwen Ma 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.12

The rapid development of smart textiles requires the large-scale fabrication of conductive fibers. In this study, we develop a simple, scalable and low-cost capillary-driven self-assembly method to prepare conductive fibers with uniform morphology, high conductivity and good mechanical strength. Fiber-shaped flexible and stretchable conductors are obtained by coating highly conductive and flexible silver nanowires (Ag NWs) on the surfaces of yarn and PDMS fibers through evaporation-induced flow and capillary-driven self-assembly, which is proven by the in situ optical microscopic observation. The density of Ag NWs and linear resistance of the conductive fibers could be regulated by tuning the assembly cycles. A linear resistance of 1.4Ω/cm could be achieved for the Ag NWs-coated nylon, which increases only 8% after 200 bending cycle, demonstrating high flexibility and mechanical stability. The flexible and stretchable conductive fibers have great potential for the application in wearable devices.

Sciatic nerve leachate of cattle causes neuronal differentiation of PC12 cells via ERK1/2 signaling pathway

Ziqiang Zhang,Yumei Liu,Xuemin Zhu,Lan Wei,Jiamin Zhu,Ke Shi,Guotao Wang,Li Pan 대한수의학회 2018 Journal of Veterinary Science Vol.19 No.4

Previous studies have shown that the sciatic nerve has neurotrophic activity, and nerve regeneration, differentiation, and axon outgrowth can be modulated by different sciatic nerve preparations. However, numerous animals may have to be sacrificed to obtain enough sciatic nerves to make a sciatic nerve preparation. Some studies have demonstrated that the role of sciatic nerve preparations in neural differentiation depends on the neurotrophins that Schwann cells secrete, and these factors are highly conserved among different species. To reduce the use of experimental animals, in this study, we made a leachate by using the sciatic nerve of cattle and explored its effect on neuronal differentiation of rat PC12 cells (a useful model for studying neuronal differentiation). Results showed the neurite outgrowth of PC12 cells treated with the cattle sciatic nerve leachate for 3, 6, and 9 days was significantly improved, and the expressions of β3-tubulin and microtubule-associated protein 2 (two neuron-specific proteins) were increased. Moreover, the ERK1/2 signaling pathway was activated after PC12 cells were incubated with cattle sciatic nerve leachate for 9 days. Thus, a sciatic nerve leachate obtained from cattle can effectively induce neuronal differentiation of rat PC12 cells via ERK1/2 signaling pathway.

Smith-Purcell Radiation with Three-Dimensional Simulation

Li, Dazhi,Imasaki, Kazuo,Yang, Ziqiang,Park, Gun-Sik,Miyamoto, Shuji,Amano, Sho,Mochizuki, Takayasu Institute of Pure and Applied Physics 2007 Japanese Journal of Applied Physics Vol.46 No.2

Avian Leukosis Virus Subgroup J and Reticuloendotheliosis Virus Coinfection Induced TRIM62 Regulation of the Actin Cytoskeleton

Ling Li,Pingping Zhuang,Ziqiang Cheng,Jie Yang,Jianmin Bi,Guihua Wang 대한수의학회 2020 Journal of Veterinary Science Vol.21 No.3

Background: Coinfection with avian leukosis virus subgroup J (ALV-J) and reticuloendotheliosis virus (REV) is common in chickens, and the molecular mechanism of the synergistic pathogenic effects of the coinfection is not clear. Exosomes have been identified as new players in the pathogenesis of retroviruses. The different functions of exosomes depend on their cargo components. Objectives: The aim of this study was to investigate the function of co-regulation differentially expressed proteins in exosomes on coinfection of ALV-J and REV. Methods: Here, viral replication in CEF cells infected with ALV-J, REV or both was detected by immunofluorescence microscopy. Then, we analyzed the exosomes isolated from supernatants of chicken embryo fibroblast (CEF) cells single infected and coinfected with ALV-J and REV by mass spectrometry. KEGG pathway enrichment analyzed the co-regulation differentially expressed proteins in exosomes. Next, we silenced and overexpressed tripartite motif containing 62 (TRIM62) to evaluate the effects of TRIM62 on viral replication and the expression levels of NCK-association proteins 1 (NCKAP1) and actin-related 2/3 complex subunit 5 (ARPC5) determined by quantitative reverse transcription polymerase chain reaction. Results: The results showed that coinfection of ALV-J and REV promoted the replication of each other. Thirty proteins, including TRIM62, NCK-association proteins 1 (NCKAP1, also known as Nap125), and Arp2/3-5, ARPC5, were identified. NCKAP1 and ARPC5 were involved in the actin cytoskeleton pathway. TRIM62 negatively regulated viral replication and that the inhibition of REV was more significant than that on ALV-J in CEF cells coinfected with TRIM62. In addition, TRIM62 decreased the expression of NCKAP1 and increased the expression of ARPC5 in coinfected CEF cells. Conclusions: Collectively, our results indicated that coinfection with ALV-J and REV competitively promoted each other's replication, the actin cytoskeleton played an important role in the coinfection mechanism, and TRIM62 regulated the actin cytoskeleton.