37 results on '"Yu-Si, Liu"'
Search Results
2. Nitrogen-Doping-Induced High-Performance Carbon Nanofiber Anodes for Potassium-Ion Storage
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Yu-Lin Bai, Yu-Si Liu, Tao Yan, Rong Feng, Chao Ma, and Kai-Xue Wang
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General Materials Science - Published
- 2023
3. Tailoring the nucleation and growth routes of discharge products for lithium-oxygen batteries through the facet engineering of Ni2P catalysts
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Se-Si Li, Xiao-Lin Zhao, Yu-Si Liu, Jian-Jun Liu, Kai-Xue Wang, and Jie-Sheng Chen
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Renewable Energy, Sustainability and the Environment ,Energy Engineering and Power Technology ,General Materials Science - Published
- 2023
4. Z-DNA/RNA Binding Protein 1 Senses Mitochondrial DNA to Induce Receptor-Interacting Protein Kinase-3/Mixed Lineage Kinase Domain-Like-Driven Necroptosis in Developmental Sevoflurane Neurotoxicity
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Wen-Yuan, Wang, Wan-Qing, Yi, Yu-Si, Liu, Qi-Yun, Hu, Shao-Jie, Qian, Jin-Tao, Liu, Hui, Mao, Fang, Cai, and Hui-Ling, Yang
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Necrosis ,Sevoflurane ,Receptor-Interacting Protein Serine-Threonine Kinases ,General Neuroscience ,Necroptosis ,Humans ,DNA, Z-Form ,RNA-Binding Proteins ,Apoptosis ,DNA, Mitochondrial ,Protein Kinases - Abstract
Developmental sevoflurane exposure leads to widespread neuronal cell death known as sevoflurane-induced neurotoxicity (SIN). Receptor-interacting protein kinase-3 (RIPK3) and mixed lineage kinase domain-like (MLKL)-driven necroptosis plays an important role in cell fate. Previous research has shown that inhibition of RIPK1 activity alone did not attenuate SIN. Since RIPK3/MLKL signaling could also be activated by Z-DNA/RNA binding protein 1 (ZBP1), the present study was designed to investigate whether ZBP1-mediated and RIPK3/MLKL-driven necroptosis is involved in SIN through in vitro and in vivo experiments. We found that sevoflurane priming triggers neuronal cell death and LDH release in a time-dependent manner. The expression levels of RIPK1, RIPK3, ZBP1 and membrane phosphorylated MLKL were also dramatically enhanced in SIN. Intriguingly, knockdown of RIPK3, but not RIPK1, abolished MLKL-mediated neuronal necroptosis in SIN. Additionally, inhibition of RIPK3-mediated necroptosis with GSK'872, rather than inhibition of apoptosis with zVAD, significantly ameliorated SIN. Further investigation showed that sevoflurane treatment causes mitochondrial DNA (mtDNA) release into the cytosol. Accordingly, ZBP1 senses cytosolic mtDNA and consequently activates RIPK3/MLKL signaling. This conclusion was reinforced by the evidence that knockdown of ZBP1 or depleting mtDNA with ethidium bromide remarkably improved SIN. Finally, the administration of the RIPK3 inhibitor GSK'872 relieved sevoflurane-induced spatial and emotional disorders without influence on locomotor activity. Altogether, these results illustrate that ZBP1 senses cytosolic mtDNA to induce RIPK3/MLKL-driven necroptosis in SIN. Elucidating the role of necroptosis in SIN will provide new insights into understanding the mechanism of anesthetic exposure in the developing brain.
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- 2022
5. Self‐Adapting and Self‐Healing Hydrogel Interface with Fast Zn 2+ Transport Kinetics for Highly Reversible Zn Anodes
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Lin Hong, Xiuming Wu, Yu‐Si Liu, Chunyang Yu, Yingchun Liu, Kaixi Sun, Chenyang Shen, Wei Huang, Yongfeng Zhou, Jie‐Sheng Chen, and Kai‐Xue Wang
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Biomaterials ,Electrochemistry ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials - Published
- 2023
6. Dendrite-free lithium anode achieved under lean-electrolyte condition through the modification of separators with F-functionalized Ti3C2 nanosheets
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Yu-Si Liu, Kai-Xue Wang, Jie-Sheng Chen, Wen-Long Bai, Qiang Zhang, Zhen Zhang, Xin Liu, and Xiao Wei
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Materials science ,Energy Engineering and Power Technology ,chemistry.chemical_element ,Separator (oil production) ,Electrolyte ,engineering.material ,Electrochemistry ,Ion ,Anode ,Fuel Technology ,Coating ,chemistry ,Chemical engineering ,engineering ,Lithium ,Short circuit ,Energy (miscellaneous) - Abstract
An unstable solid electrolyte interphase (SEI) and chaotic lithium ion flux are key impediments to commercial high-energy-density lithium batteries because of the uncontrolled growth of rigid lithium dendrites, which would pierce through the conventional polypropylene (PP) separator, causing short circuit and safety issues. Herein, the homogenization of lithium ion flux and the generation of stable SEI layers on lithium anodes were achieved via coating a fluorine-functionalized Ti3C2 (F-Ti3C2) nanosheets on PP separator (F-Ti3C2@PP). F-Ti3C2 nanosheets provide abundant ions pathways to homogeneously manipulate lithium ion flux and increase the Young’s modulus and electrolyte wettability of the separators. In addition, F species derived from the F-Ti3C2 nanosheets would promote the formation of LiF-rich SEI film. The synergistic effect contribute to the uniform lithium deposition. Symmetric Li|Li, asymmetric Li|Cu and full Li|LiFePO4 cells incorporated with the modified separators exhibit improved electrochemical performance even under lean electrolyte conditions. This work provides a feasible strategy to improve the performance of lithium batteries through both fluoridized SEI formation and lithium ion flux manipulation.
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- 2022
7. Research on the Influence of Reflected Shock Wave on Continuously Rotating Detonation Engine
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Yu-Si, Liu, Yang, Li, Yu-hui, Wang, and Jian-ping, Wang
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- 2015
- Full Text
- View/download PDF
8. mTORC1-Dependent and GSDMD-Mediated Pyroptosis in Developmental Sevoflurane Neurotoxicity
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Wen-Yuan, Wang, primary, Wan-Qing, Yi, additional, Qi-Yun, Hu, additional, Yu-Si, Liu, additional, Shao-Jie, Qian, additional, Jin-Tao, Liu, additional, Hui, Mao, additional, Fang, Cai, additional, and Hui-Ling, Yang, additional
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- 2022
- Full Text
- View/download PDF
9. [Characteristics and Impact Factors of Number Concentration of Primary Biological Aerosol Particles in Beijing]
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Lin-Lin, Liang, Chang, Liu, Xu-Yan, Liu, Wan-Yun, Xu, Gen, Zhang, Hong-Bing, Cheng, and Yu-Si, Liu
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Aerosols ,Air Pollutants ,Beijing ,Humans ,Particulate Matter ,Environmental Monitoring - Abstract
Primary biological aerosol particles (PBAP) are an important part of ambient aerosols. Both living and dead organisms not only influence human health and air quality but also play important roles in regulating certain atmospheric processes and affect the hydrological cycle and climate change. In this study, flow cytometry (FCM) was utilized in combination with the simultaneous use of permeant (SYBR Green I) and impermeant (propidium iodide, PI) nucleic acid fluorescent staining to detect and quantify the viable and dead airborne biological particles. At the same time, based on this method, the dead/viable PBAP in a Beijing urban area was detected and quantified. Moreover, the influence of environmental factors on the concentrations of primary biological aerosol particles was illuminated. The results showed that the media number concentration of dead and alive PBAP in the Beijing urban area during summer (1.03×10
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- 2022
10. Boosting the electrochemical performance of Li–O2 batteries with DPPH redox mediator and graphene-luteolin-protected lithium anode
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Jie-Sheng Chen, Wen-Long Bai, Qiang Zhang, Zhixin Xu, Xin Chen, Zhen Zhang, Xiao Wei, Baobao Chang, Kai-Xue Wang, and Yu-Si Liu
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Materials science ,Renewable Energy, Sustainability and the Environment ,Graphene ,DPPH ,Radical ,Inorganic chemistry ,Energy Engineering and Power Technology ,02 engineering and technology ,Overpotential ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrochemistry ,01 natural sciences ,Redox ,0104 chemical sciences ,Anode ,law.invention ,Metal ,chemistry.chemical_compound ,chemistry ,law ,visual_art ,visual_art.visual_art_medium ,General Materials Science ,0210 nano-technology - Abstract
Aprotic Li-O2 batteries with high theoretical energy density are regarded as promising next-generation energy storage devices. However, the accumulation of discharge products (Li2O2) duiring the discharge/charge processes would lead to high overpotential, low round-trip efficiency and poor cycling stability of the batteries. Soluble redox mediators (RMs) have been proved to be efficient in promoting the oxidation of Li2O2 particles. However, the self-discharge of the electrochemically oxidized RMs (RMsox) on the surface of Li metal would accelerate the formation of lithium dendrites. In this work, nitrogenous radicals, 1,1-Diphenyl-2-picrylhydrazyl radical 2,2-Diphenyl-1-(2,4,6-trinitrophenyl) hydrazyl (DPPH), is designed and employed as a RMs to lower the overpotential of Li–O2 batteries. Moreover, the self-discharge of the oxidized DPPH on the surface of Li metal and the formation of lithium dendrites are successfully suppressed by the formation of graphene/luteolin protective layer on Li metal. Consequently, an ultrastable cycle stability (>150 cycles) is achieved with DPPH and the stable graphene/luteolin protective layer for the Li metal anodes. These synergistic effect of RMs and stable Li protective layer may inspire the development of sustainable and durable Li–O2 batteries.
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- 2020
11. Synergistic Effects of Resveratrol and Temozolomide Against Glioblastoma Cells: Underlying Mechanism and Therapeutic Implications
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Xue Song, Jia Liu, Yu-Si Liu, Mo-Li Wu, and Jiao Wu
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0301 basic medicine ,Temozolomide ,Methyltransferase ,biology ,Resveratrol ,medicine.disease ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,0302 clinical medicine ,Oncology ,chemistry ,Apoptosis ,Cell culture ,030220 oncology & carcinogenesis ,Glioma ,Survivin ,biology.protein ,medicine ,Cancer research ,STAT3 ,medicine.drug - Abstract
Purpose Temozolomide (TMZ) is a commonly used anti-glioblastoma (GBM) drug. However, glioblastoma cells frequently show primary and acquired resistance to TMZ. As a promising anti-GBM candidate, resveratrol (Res) faces the similar problem as TMZ. Although resveratrol combined with TMZ (Res/TMZ) has been reported to be used to treat GBMs, it remains unclear whether this combination is broad-spectrum for all glioma cells until now, especially for GBM cells/cases with dual drug resistance. The study aimed to evaluate the synergistic effects of resveratrol and TMZ against GBMs and identify the underlying mechanisms. Materials and methods Drug sensitivities of rat RG-2, human LN-18 and LN-428 cell lines and effectiveness of Res/TMZ combinations were investigated via multiple experimental methods. O6-methylguanine-DNA methyltransferase (MGMT) was observed by Western blotting and immunocytochemistry (ICC). Transducer and activator of transcription 3 (STAT3) signaling pathway and expression changes of STAT3-related gene were detected to explore the possible synergistic mechanism. Results One hundred micromolar resveratrol and 500 μM TMZ inhibited the growth of RG-2 cells and the low-dose combination (25 μM/250 μM) showed similar suppressive effects. LN-18 and, especially, LN-428 cells were neither sensitive to 100 μM resveratrol nor to 500 μM TMZ, while their growth was suppressed by combination of 75 μM Res/750 μM TMZ with the suppressive rates of 62.5% and 28.6% and apoptosis rates of 11.9% and 7.4%, respectively. Resveratrol had regulatory effect on the expression of MGMT and it could significantly down-regulate MGMT overexpression caused by TMZ. In addition, STAT3/Bcl-2/survivin signaling pathway was also remarkably inhibited in Res/TMZ-treated GBM cells. Conclusion Our results demonstrated synergistic effects of Res/TMZ on RG-2 cells and their bilaterally sensitizing effects to LN-18 and LN-428 cells. Frequent upregulation of MGMT and activation of STAT3 are the unfavorable factors for the treatment of GBMs and they may be the potential targets of Res/TMZ therapy.
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- 2020
12. STAT3 signaling statuses determine the fate of resveratrol-treated anaplastic thyroid cancer cells
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Jia Liu, Xiao-Ting Tian, Yu-Si Liu, Mo-Li Wu, Pei-Nan Li, Jiao Wu, and Yi-Tian Li
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STAT3 Transcription Factor ,Cancer Research ,Cell Survival ,Apoptosis ,Resveratrol ,Thyroid Carcinoma, Anaplastic ,Leukemia Inhibitory Factor ,Antioxidants ,chemistry.chemical_compound ,Downregulation and upregulation ,Cell Line, Tumor ,Gene expression ,Genetics ,medicine ,Humans ,0501 psychology and cognitive sciences ,Thyroid Neoplasms ,Phosphorylation ,Anaplastic thyroid cancer ,STAT3 ,Cell Proliferation ,0505 law ,biology ,Chemistry ,05 social sciences ,General Medicine ,medicine.disease ,Oncology ,Cell culture ,050501 criminology ,STAT protein ,Cancer research ,biology.protein ,Leukemia inhibitory factor ,hormones, hormone substitutes, and hormone antagonists ,Signal Transduction ,050104 developmental & child psychology - Abstract
Backgrounds Anaplastic thyroid cancer/ATC is highly lethal malignancy without reliable chemotherapeutic drug. Resveratrol possesses anti-ATC activities but encounters resistance in some cases due to certain unknown reason(s). Objective Because signal transducer and activator of transcription/STAT3 signaling is critical for ATC cell survival and the main molecular target of resveratrol, its roles in determining the fates of resveratrol-treated ATC cells were investigated here. Methods Human THJ-11T, THJ-16 and THJ-21T ATC cell lines were treated by 100 μM resveratrol and their growth, statuses of STAT3 signaling and STAT3-related gene expression were examined. The relevance of STAT3 activation with resveratrol resistance was elucidated using STAT selective inhibitor AG490. Leukemia inhibitory factor/LIF expression and phosphorylated-STAT3/p-STAT3 nuclear translocation in ATC tissues were immunohistochemically analyzed. Results Resveratrol inhibited proliferation, p-STAT3 nuclear translocation as well as LIF and STAT3 expression of THJ-16T and THJ-21T but not THJ-21T cells which showed LIF upregulation and more frequent p-STAT3 nuclear translocation. AG490 significantly prevent p-STAT3 nuclear translocation, and reversed the resveratrol tolerance of THJ-11T cells. Immonohistochemical staining revealed 14.3% (4/28) of LIF and 3.6% (1/28) of p-STAT3 detection in noncancerous ATC-surrounding tissues, which increased to 89.5% (17/19) and 52.6% (10/19) respectively among ATC specimens. The correlative analysis indicated the relevance of LIF expression and STAT3 activation (r= 0.825; P Conclusions The status of STAT3 activation and LIF expression are closely correlated with the therapeutic effect of resveratrol on ATCs. Frequent LIF upregulation and STAT3 activation are the unfavorable factors of ATCs and the potential targets of anti-ATC therapy.
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- 2020
13. Surface engineering donor and acceptor sites with enhanced charge transport for low-overpotential lithium–oxygen batteries
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Kai-Xue Wang, Jie-Sheng Chen, Wen-Long Bai, Zhi-Peng Cai, Xin Liu, Qiang Zhang, Xiao Liang, Yu-Si Liu, Shu-Mao Xu, and Chuan Zhao
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Materials science ,Renewable Energy, Sustainability and the Environment ,Energy Engineering and Power Technology ,chemistry.chemical_element ,02 engineering and technology ,Overpotential ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Acceptor ,Cathode ,0104 chemical sciences ,Catalysis ,law.invention ,Electron transfer ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,law ,General Materials Science ,Lithium ,0210 nano-technology ,Carbon ,Lithium peroxide - Abstract
Inferior charge transport in discharge products is one of the main factors restricting the technological potential of lithium-oxygen batteries. Here, we propose a strategy to enhance charge transport in discharge products by surface engineering of cathode catalysts with donor and acceptor sites to improve solid-solid interfacial electron transfer properties between catalysts and discharge products. Free-standing layered double oxides loaded with pyrolyzed sodium poly(aminobenzenesulfonate)-derived sulfur-doped carbon nanosheets and carbon nanosheets with sulfoxide groups are synthesized and utilized to investigate donor and acceptor sites effect on the performance of lithium-oxygen batteries. The free-standing cathode with hybrid donor and acceptor sites is capable of operation in oxygen with distinct (dis)charge plateau and superior cycling stability (over 60 cycles at a fixed capacity of 0.53 mAh cm−2). The superior properties are attributed to the enhanced charge transport in lithium peroxide by the formation of hole polarons/Li+ vacancies on acceptor sites and electron polarons/disordered lithium peroxide phase on donor sites. This work provides a promising route to enhance defective charge transport in discharge products by optimization of donor and acceptor sites on cathode catalysts for high-performance lithium-oxygen batteries.
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- 2020
14. 3D ordered macroporous MoO2 attached on carbonized cloth for high performance free-standing binder-free lithium–sulfur electrodes
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Xin Liu, Chao Ma, Kai-Xue Wang, Xiao Wei, Shu-Mao Xu, Xue-Yan Wu, Yu-Si Liu, Jie-Sheng Chen, Wen-Long Bai, and Yu-Lin Bai
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Materials science ,Nanostructure ,Renewable Energy, Sustainability and the Environment ,Carbonization ,Diffusion ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,021001 nanoscience & nanotechnology ,Electrochemistry ,Sulfur ,chemistry ,Chemical engineering ,Electrode ,General Materials Science ,Lithium sulfur ,0210 nano-technology ,Sulfur utilization - Abstract
Lithium–sulfur (Li–S) batteries have received increasing attention due to their high energy density. However, it is still challenging to inhibit the diffusion of polysulfides and achieve high sulfur utilization. Herein, we designed and prepared a free-standing and binder-free electrode for high-performance Li–S batteries by in situ growth of three-dimensional ordered macroporous MoO2 on carbonized nonwoven cloth (3DOM MoO2/CC). After the uptake of Li2S6, the obtained MoO2/CC–Li2S6 electrode with a high sulfur loading of 3.26 mg cm−2 delivers a large discharge capacity of 1267 mA h g−1 at 0.1C. A high discharge capacity of 621 mA h g−1 is still retained after 500 cycles at 2C. The excellent electrochemical performance of this MoO2/CC–Li2S6 electrode is attributed to the unique nanostructure and strong chemical interaction between MoO2 and polysulfides. 3DOM MoO2 not only guarantees the high loading of sulfur but also suppresses the diffusion of polysulfides. The carbonized nonwoven cloth (CC) functions as the basic support for 3DOM MoO2, enhancing the electronic conductivity and mechanical properties of the free-standing electrodes. This work provides a feasible strategy for the construction of high-performance free-standing binder-free Li–S electrodes.
- Published
- 2019
15. Germanium nanoparticles supported by 3D ordered macroporous nickel frameworks as high-performance free-standing anodes for Li-ion batteries
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Jie-Sheng Chen, Kai-Xue Wang, Michelle M. Harris, Jihao Li, Yu-Si Liu, and Xin Liu
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Materials science ,General Chemical Engineering ,Alloy ,Nanoparticle ,chemistry.chemical_element ,Germanium ,02 engineering and technology ,Electrolyte ,engineering.material ,010402 general chemistry ,Electrochemistry ,01 natural sciences ,Industrial and Manufacturing Engineering ,law.invention ,law ,Environmental Chemistry ,Calcination ,Porosity ,General Chemistry ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Anode ,Chemical engineering ,chemistry ,engineering ,0210 nano-technology - Abstract
Germanium-based materials are gaining increasing attention as promising anodes for Li-ion batteries (LIBs) due to their high specific capacity, good cycling stability and excellent rate performance. Similarly to Si, Ge-based anodes undergo a huge volume expansion and contraction during Li intercalation and deintercalation, causing a rapid and irreversible capacity decay. In this work, Ge nanoparticles are uniformly attached to a 3D ordered macroporous (3DOM) Ni framework (Ge/3DOM-Ni) via a facile drop-coating technique in order to address the volume expansion and stability issues plaguing Ge anodes. The 3D ordered macroporous Ni frameworks with high porosity act not only as highly conductive current collectors but also as a robust porous support for the formation of a thin layer of Ge nanoparticles. The three-dimensional porous network facilitates the penetration of the electrolyte and lithium ions. The possible alloy interface generated among the Ge nanoparticles and Ni framework during the calcination process ensures good electric contact among the nanoparticles and the 3D ordered macroporous Ni framework. When used as self-supporting binder-free anodes for lithium ion batteries, the Ge/3DOM-Ni electrode shows high rate performance and excellent structural and cycling stability. This work provides a facile and effective strategy for improving the electrochemical performance of Ge-based anodes.
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- 2018
16. Thiophene Derivative as a High Electrochemical Active Anode Material for Sodium-Ion Batteries: The Effect of Backbone Sulfur
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Xin-Yang Zhao, Kai-Xue Wang, Yu-Lin Bai, Chao Ma, Liang Wu, Jie Sheng Chen, Zhao Jin, Yu-Si Liu, and Huai Sun
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Materials science ,General Chemical Engineering ,Sodium ,Inorganic chemistry ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrochemistry ,01 natural sciences ,Sulfur ,0104 chemical sciences ,Anode ,Ion ,chemistry.chemical_compound ,chemistry ,Electrode ,Materials Chemistry ,Thiophene ,0210 nano-technology ,Derivative (chemistry) - Published
- 2018
17. Nitrogen-doped carbon nanotube sponge with embedded Fe/Fe3C nanoparticles as binder-free cathodes for high capacity lithium–sulfur batteries
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Chao Ma, Jie-Sheng Chen, Yu-Lin Bai, Xing-Hua Liang, Kai-Xue Wang, Xin Liu, Qian-Chen Zhu, Xue-Yan Wu, Yu-Si Liu, and Xiao Wei
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Materials science ,Renewable Energy, Sustainability and the Environment ,Carbonization ,Composite number ,chemistry.chemical_element ,Nanoparticle ,02 engineering and technology ,General Chemistry ,Carbon nanotube ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrochemistry ,01 natural sciences ,Sulfur ,Cathode ,0104 chemical sciences ,law.invention ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,law ,General Materials Science ,0210 nano-technology ,Melamine - Abstract
Lithium–sulfur (Li–S) batteries as a promising next-generation energy storage device have received increasing attention recently. However, it is still challenging to achieve high sulfur loading and high areal capacity in the cathodes. Herein, we design a composite of carbon-wrapped Fe/Fe3C nanoparticles grown in a carbonized melamine sponge (Fe/Fe3C@N-CNT) as a free-standing conductive framework and host scaffold for sulfur loading. High sulfur content up to 86.9 wt% and overall mass loading as high as ∼14.44 mg cm−2 are achieved in the resultant Fe/Fe3C@N-CNT/S composite. A high discharge capacity of 1359 mA h g−1 is delivered for this Fe/Fe3C@N-CNT/S composite at 0.1C, and 561 mA h g−1 is retained after 150 cycles. The high electrochemical performance of this Fe/Fe3C@N-CNT/S composite is attributed to the synergistic effect of Fe/Fe3C nanoparticles, carbon coating, and N-doped carbon nanotubes in the Fe/Fe3C@N-CNT cathode.
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- 2018
18. A Composite of Carbon-Wrapped Mo2C Nanoparticle and Carbon Nanotube Formed Directly on Ni Foam as a High-Performance Binder-Free Cathode for Li-O2Batteries
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Chao Ma, Jie-Sheng Chen, Shu-Mao Xu, Qian-Cheng Zhu, Yu-Si Liu, Xiao Wei, Yong-Xian Zhou, Yu-Cai Cao, Kai-Xue Wang, Hua-Sheng Xu, and Michelle M. Harris
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Materials science ,Ammonium heptamolybdate ,Carbonization ,Oxygen evolution ,Nanoparticle ,chemistry.chemical_element ,02 engineering and technology ,Carbon nanotube ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Cathode ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,law.invention ,Biomaterials ,chemistry.chemical_compound ,chemistry ,law ,Electrochemistry ,Nanoarchitectures for lithium-ion batteries ,Composite material ,0210 nano-technology ,Carbon - Abstract
Cathode design is indispensable for building Li-O2 batteries with long cycle life. A composite of carbon-wrapped Mo2C nanoparticles and carbon nanotubes is prepared on Ni foam by direct hydrolysis and carbonization of a gel composed of ammonium heptamolybdate tetrahydrate and hydroquinone resin. The Mo2C nanoparticles with well-controlled particle size act as a highly active oxygen reduction reactions/oxygen evolution reactions (ORR/OER) catalyst. The carbon coating can prevent the aggregation of the Mo2C nanoparticles. The even distribution of Mo2C nanoparticles results in the homogenous formation of discharge products. The skeleton of porous carbon with carbon nanotubes protrudes from the composite, resulting in extra voids when applied as a cathode for Li-O2 batteries. The batteries deliver a high discharge capacity of ≈10 400 mAh g−1 and a low average charge voltage of ≈4.0 V at 200 mA g−1. With a cutoff capacity of 1000 mAh g−1, the Li-O2 batteries exhibit excellent charge–discharge cycling stability for over 300 cycles. The average potential polarization of discharge/charge gaps is only ≈0.9 V, demonstrating the high ORR and OER activities of these Mo2C nanoparticles. The excellent cycling stability and low potential polarization provide new insights into the design of highly reversible and efficient cathode materials for Li-O2 batteries.
- Published
- 2016
19. Numerical study of rotating detonation engine with an array of injection holes
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Xue-Yao Han, Jian-Ping Wang, Yu-Si Liu, and Songbai Yao
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Physics ,Arrhenius equation ,020301 aerospace & aeronautics ,Computer simulation ,Mechanical Engineering ,Detonation ,General Physics and Astronomy ,02 engineering and technology ,Mechanics ,Fuel injection ,01 natural sciences ,010305 fluids & plasmas ,Euler equations ,symbols.namesake ,Classical mechanics ,0203 mechanical engineering ,0103 physical sciences ,symbols ,Transient (oscillation) - Abstract
This paper aims to adopt the method of injection via an array of holes in three-dimensional numerical simulations of a rotating detonation engine (RDE). The calculation is based on the Euler equations coupled with a one-step Arrhenius chemistry model. A pre-mixed stoichiometric hydrogen–air mixture is used. The present study uses a more practical fuel injection method in RDE simulations, injection via an array of holes, which is different from the previous conventional simulations where a relatively simple full injection method is usually adopted. The computational results capture some important experimental observations and a transient period after initiation. These phenomena are usually absent in conventional RDE simulations due to the use of an idealistic injection approximation. The results are compared with those obtained from other numerical studies and experiments with RDEs.
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- 2016
20. Core-shell anatase anode materials for sodium-ion batteries: the impact of oxygen vacancies and nitrogen-doped carbon coating
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Jie-Sheng Chen, Xue-Yan Wu, Yu-Lin Bai, Kai-Xue Wang, Yu-Si Liu, Raxidin Xarapatgvl, and Xin Liu
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Anatase ,Materials science ,Sodium ,Reducing atmosphere ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrochemistry ,01 natural sciences ,Oxygen ,0104 chemical sciences ,Ion ,law.invention ,Anode ,chemistry ,Chemical engineering ,law ,General Materials Science ,Calcination ,0210 nano-technology - Abstract
In this work, the impact of oxygen vacancies and nitrogen-doped carbon coating on the sodium-ion storage properties of anatase TiO2 has been demonstrated. Oxygen vacancies and nitrogen-doped carbon coating were introduced simultaneously by the calcination of core–shell structured TiO2 spheres in a reducing atmosphere. Compared to the anatase TiO2 with and without oxygen vacancies, TiO2−x@NC exhibits much better electrochemical performance in the storage of sodium ions. A high reversible capacity of 245.6 mA h g−1 is maintained at 0.1 A g−1 after 200 cycles, and a high specific capacity of 155.6 mA h g−1 is achieved at a high rate of 5.0 A g−1. The significantly improved electrochemical performance of the core–shell structured anatase TiO2 spheres is attributed to the synergistic effect of the oxygen vacancies in the anatase lattice and surface nitrogen-doped carbon coating. This work provides an efficient strategy for improving the electrochemical performance of metal–oxide-based electrode materials for sodium-ion batteries.
- Published
- 2019
21. [Analysis of Different Particle Sizes, Pollution Characteristics, and Sources of Atmospheric Aerosols During the Spring Dust Period in Beijing]
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Yang, Yang, Xing-Ru, Li, Xi, Chen, Shui-Qiao, Liu, Yu-Si, Liu, Jing, Xu, Li-Li, Wang, Ming-Hui, Tao, and Ge-Hui, Wang
- Abstract
To understand the evolution of the physical and chemical properties of dust aerosols in the atmosphere, the concentrations and chemical compositions of differently sized particles were continuously observed and analyzed using an ion chromatograph and carbonaceous analyzer during the outbreak of dust in May 2017 in Beijing. The concentrations of total suspended particulate (TSP), water-soluble organic carbon (WSOC), elemental carbon (EC), OC, and water-soluble inorganic ions were (2237.59±681.49), (29.90±18.05), (1.46±3.05), (67.35±29.07), and (136.75±46.38) μg·m
- Published
- 2019
22. Neuron-Inspired Design of High-Performance Electrode Materials for Sodium-Ion Batteries
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Kai-Xue Wang, Yu-Lin Bai, Chao Ma, Jie-Sheng Chen, and Yu-Si Liu
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Materials science ,Intercalation (chemistry) ,Composite number ,General Engineering ,General Physics and Astronomy ,Nanotechnology ,02 engineering and technology ,Carbon nanotube ,Nanoflower ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Anode ,law.invention ,Electron transfer ,law ,Lattice (order) ,General Materials Science ,0210 nano-technology ,Nanosheet - Abstract
Sodium-ion batteries (SIBs) are generally considered as promising cheap alternatives of lithium-ion batteries for stationary renewable energy storage and have received increasing attention in recent years. The exploration of anode materials with efficient electron transportation is essential for improving the performance of SIBs. Inspired by the signal transfer mode of a neuron, we designed a composite by stringing MoS2 nanoflower (soma) with multiwall carbon nanotubes (MWCNTs) (axons). High-resolution TEM observation reveals a lattice matching growth mechanism of MoS2 nanosheets on the interface of MWCNTs and the lattice expansion of the (002) plane of MoS2. The lattice matching among the MoS2 nanosheet and MWCNT could facilitate electron transfer and structure maintenance upon cycling. The expanded distance of the (002) plane of MoS2 would also promote the sodium-ion intercalation/deintercalation kinetics of the composite. Benefiting from the structural features, when used as an anode material for SIBs,...
- Published
- 2018
23. Structure of an oblique detonation wave induced by a wedge
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Yupeng Liu, Jian-Ping Wang, Dan Wu, and Yu-Si Liu
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Physics ,020301 aerospace & aeronautics ,Chemical reaction model ,Mach reflection ,Mechanical Engineering ,Detonation ,General Physics and Astronomy ,Oblique case ,02 engineering and technology ,Inflow ,Mechanics ,01 natural sciences ,Wedge (geometry) ,010305 fluids & plasmas ,Euler equations ,symbols.namesake ,0203 mechanical engineering ,Mach number ,0103 physical sciences ,symbols - Abstract
The structure of an oblique detonation wave (ODW) induced by a wedge is investigated via numerical simulations and Rankine–Hugoniot analysis. The two-dimensional Euler equations coupled with a two-step chemical reaction model are solved. In the numerical results, four configurations of the Chapman–Jouguet (CJ) ODW reflection (overall Mach reflection, Mach reflection, regular reflection, and non-reflection) are observed to take place sequentially as the inflow Mach number increases. According to the numerical and analytical results, the change of the CJ ODW reflection configuration results from the interaction among the ODW, the CJ ODW, and the centered expansion wave.
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- 2015
24. Design of terahertz-wave Doppler interferometric velocimetry for detonation physics
- Author
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Li-Guo Zhu, Wang Detian, Liu-Wei Guo, Xu Zhang, Shou-Xian Liu, Zhai Zhaohui, Chang-Lin Sun, Zhong Sencheng, Jiang Li, Qiao Liu, Kun Meng, Du Lianghui, and Yu-Si Liu
- Subjects
010302 applied physics ,Physics ,Wavefront ,Physics and Astronomy (miscellaneous) ,Explosive material ,Terahertz radiation ,business.industry ,Detonation velocity ,Detonation ,02 engineering and technology ,Velocimetry ,021001 nanoscience & nanotechnology ,01 natural sciences ,symbols.namesake ,Interferometry ,Optics ,0103 physical sciences ,symbols ,0210 nano-technology ,business ,Doppler effect - Abstract
The diagnosis of the initiation and growth of detonation in high explosives (HEs) is important in detonation physics. We designed and experimentally demonstrated a non-invasive high-precision free-space terahertz-wave Doppler interferometric velocimetry (TDV) design for diagnosing the transient detonation processes in HEs. The system can non-intrusively record the propagation of the shock/detonation wavefront inside HEs continuously and measure key detonation parameters (position/displacement, detonation velocity, etc.). A detailed quasi-optical design for TDV is discussed. The terahertz penetration ability and the refractive index of representative HEs are presented in the frequency range of 0.2–1.4 THz. Additionally, a typical shock-to-detonation transition of an insensitive high explosive was studied using a prototype 0.212 THz TDV system, which demonstrated the high precision of displacement measurements made using I/Q demodulation. Furthermore, the performance of the TDV technique is discussed. TDV may enable non-invasive and high-precision diagnostics for detonation and shockwave physics.
- Published
- 2020
25. Dandelion-clock-inspired preparation of core-shell TiO2@MoS2 composites for high performance sodium ion storage
- Author
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Chao Ma, Yu-Si Liu, Kai-Xue Wang, Xiao Wei, Xue-Yan Wu, Jie-Sheng Chen, and Yu-Lin Bai
- Subjects
Materials science ,Mechanical Engineering ,Sodium ,Metals and Alloys ,Rational design ,chemistry.chemical_element ,Dandelion ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Energy storage ,0104 chemical sciences ,Anode ,Electron transfer ,X-ray photoelectron spectroscopy ,chemistry ,Mechanics of Materials ,Materials Chemistry ,Composite material ,0210 nano-technology ,High-resolution transmission electron microscopy - Abstract
Sodium ion batteries (SIBs) have great potential to be next-generation energy storage devices because of abundant sodium sources and its low cost. To improve the performance of SIBs, electrode materials with high capacities and cycling stabilities are highly desirable. Herein, inspired by the structure of a dandelion clock, core-shell TiO2@MoS2 composites were prepared by growing MoS2 nanoflakes on TiO2 nanospheres via a facial solvothermal method. The electrochemically stable TiO2 nanospheric core which likes the receptacle in a dandelion clock provides a robust support for the radial growth of MoS2 nanosheets, which like the pappi in the dandelion clock. The dandelion-clock-like structure can effectively prevent the aggregation of the MoS2 nanosheets, providing increased active sites. Strong interface interaction between TiO2 and MoS2 as revealed by XPS and HRTEM analyses could significantly promote the electron transfer and maintain the structural integrity of the composites. When used as anode materials for SIBs, the TiO2@MoS2 composites exhibit remarkable improved rate and cycling performance. This work indicates that the consideration of the morphology and structure is the key for the rational design and preparation of high performance electrode materials.
- Published
- 2020
26. Free-standing hybrid porous membranes integrated with transition metal nitride and carbide nanoparticles for high-performance lithium-sulfur batteries
- Author
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Chao Ma, Kai-Xue Wang, Xiao Wei, Xue-Yan Wu, Xin Liu, Yu-Lin Bai, Jie-Sheng Chen, Zhen Wang, and Yu-Si Liu
- Subjects
Materials science ,General Chemical Engineering ,Composite number ,chemistry.chemical_element ,Nanoparticle ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Sulfur ,Industrial and Manufacturing Engineering ,0104 chemical sciences ,Carbide ,chemistry.chemical_compound ,Membrane ,chemistry ,Chemical engineering ,Environmental Chemistry ,0210 nano-technology ,Hybrid material ,Dissolution ,Polysulfide - Abstract
Lithium-sulfur batteries are considered as a promising candidate for next-generation energy-storage applications because of its high energy densities. However, the practical utilization of lithium–sulfur batteries is compromised by fast capacity decay, limited sulfur loading and significant polysulfide shuttling. Herein, we designed and prepared a free-standing lithium-sulfur electrode by loading sulfur into a hybrid material (Mo3Ni3N/Mo2C-CBC/S) constructed by growing Mo3Ni3N/Mo2C nanoparticles on carbonized bacterial cellulose film (CBC). High sulfur content up to 70 wt% and high areal sulfur loading of 15.5 mg cm−2 in Mo3Ni3N/Mo2C-CBC/S membrane are achieved. Reversible specific capacities of 1218 and 823 mA h g−1 are delivered for current rates of 0.1 and 1.0 C, respectively. A high capacity over 500 mA h g−1 is retained after 500 cycles at 1.0 C. The superior electrochemical performance of Mo3Ni3N/Mo2C-CBC/S composite is attributed to the unique structure feature and the synergistic effect of the Mo3Ni3N and Mo2C nanoparticles. The Mo3Ni3N/Mo2C component could suppress the dissolution and shuttling of the polysulfides and Mo2C could improve the electronic conductivity of the composite, consequently contributing to the excellent electrochemical performance of the composite.
- Published
- 2019
27. Rubber-based carbon electrode materials derived from dumped tires for efficient sodium-ion storage
- Author
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Chao Ma, Yu-Si Liu, Kai-Xue Wang, Jie-Sheng Chen, Shi-Feng Wang, Yu-Lin Bai, Xiao Wei, and Zhen-Yue Wu
- Subjects
Materials science ,Composite number ,chemistry.chemical_element ,Nanoparticle ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrochemistry ,01 natural sciences ,Energy storage ,0104 chemical sciences ,Anode ,Inorganic Chemistry ,chemistry ,Natural rubber ,Chemical engineering ,visual_art ,visual_art.visual_art_medium ,0210 nano-technology ,Pyrolysis ,Carbon - Abstract
The development of sustainable and low cost electrode materials for sodium-ion batteries has attracted considerable attention. In this work, a carbon composite material decorated with in situ generated ZnS nanoparticles has been prepared via a simple pyrolysis of the rubber powder from dumped tires. Upon being used as an anode material for sodium-ion batteries, the carbon composite shows a high reversible capacity and rate capability. A capacity as high as 267 mA h g-1 is still retained after 100 cycles at a current density of 50 mA g-1. The well dispersed ZnS nanoparticles in carbon significantly enhance the electrochemical performance. The carbon composites derived from the rubber powder are proposed as promising electrode materials for low-cost, large-scale energy storage devices. This work provides a new and effective method for the reuse of dumped tires, contributing to the recycling of valuable waste resources.
- Published
- 2018
28. Spectral analysis and self-adjusting mechanism for oscillation phenomenon in hydrogen-oxygen continuously rotating detonation engine
- Author
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Yang Li, Yongsheng Li, Yuhui Wang, Jian-Ping Wang, and Yu-Si Liu
- Subjects
Materials science ,Spacecraft ,Hydrogen ,business.industry ,Mechanical Engineering ,Detonation velocity ,Detonation ,Aerospace Engineering ,chemistry.chemical_element ,Thermodynamics ,TL1-4050 ,Mechanics ,Spectral analysis ,Oxygen ,Continuously rotating detonation ,chemistry ,Annulus (firestop) ,Combustor ,Hydrogen-oxygen detonation ,Self-adjusting mechanism ,Combustion chamber ,Detonation engines ,business ,Motor vehicles. Aeronautics. Astronautics - Abstract
The continuously rotating detonation engine (CRDE) is a new concept of engines for aircraft and spacecraft. Quasi-stable continuously rotating detonation (CRD) can be observed in an annular combustion chamber, but the sustaining, stabilizing and adjusting mechanisms are not yet clear. To learn more deeply into the CRDE, experimental studies have been carried out to investigate hydrogen-oxygen CRDE. Pressure histories are obtained during each shot, which show that stable CRD waves are generated in the combustor, when feeding pressures are higher than 0.5 MPa for fuel and oxidizer, respectively. Each shot can keep running as long as fresh gas feeding maintains. Close-up of the pressure history shows the repeatability of pressure peaks and indicates the detonation velocity in hydrogen–oxygen CRD, which proves the success of forming a stable CRD in the annular chamber. Spectrum of the pressure history matches the close-up analysis and confirms the CRD. It also shows multi-wave phenomenon and affirms the fact that in this case a single detonation wave is rotating in the annulus. Moreover, oscillation phenomenon is found in pressure peaks and a self-adjusting mechanism is proposed to explain the phenomenon.
- Published
- 2015
29. Numerical investigations of the restabilization of hydrogen–air rotating detonation engines
- Author
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Yu-Si Liu, Yan Liu, Dan Wu, and Jian-Ping Wang
- Subjects
Range (particle radiation) ,Stagnation temperature ,Hydrogen ,Renewable Energy, Sustainability and the Environment ,Chemistry ,Detonation ,Energy Engineering and Power Technology ,Thermodynamics ,chemistry.chemical_element ,Mechanics ,Condensed Matter Physics ,Stagnation point ,Pressure coefficient ,Fuel Technology ,Head (vessel) ,Stagnation pressure - Abstract
Based on 3D numerical simulations, the restabilization of hydrogen–air rotating detonation engines (RDEs) from one stable state to another after the operating conditions are changed is investigated. After a sudden change is imposed on the injection stagnation pressure, the transition process is clarified and the transition time, needed by the RDE to stabilize at a new state, is calculated. It is found that the sudden change of the stagnation pressure has an immediate influence on the average axial velocity at the head end of the RDE, which increases abruptly and instantly with the sudden rise of the stagnation pressure. After that, the average axial velocity drops and the average pressure increases gradually at the head end until they reach a new stable state. The average pressure has a bounce and the average axial velocity fluctuates at the head end in the transition process of the sudden decrease of the stagnation pressure. The total transition time increases with the variation range of the stagnation pressure. However, the initial adjusting time is independent of the variation range of the stagnation pressure and it is about twice the cycle period of the detonation wave around the chamber, demonstrating the high stability of the RDE.
- Published
- 2014
30. Incorporation of heterostructured Sn/SnO nanoparticles in crumpled nitrogen-doped graphene nanosheets for application as anodes in lithium-ion batteries
- Author
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Jie-Sheng Chen, Qian-Cheng Zhu, Xiao Wei, Jie Long, Kai-Xue Wang, Fei-Hu Du, and Yu-Si Liu
- Subjects
Nitrogen doped graphene ,Materials science ,Graphene ,Diffusion ,Composite number ,Metals and Alloys ,Nanoparticle ,chemistry.chemical_element ,Nanotechnology ,General Chemistry ,Catalysis ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Anode ,law.invention ,Ion ,chemistry ,law ,Materials Chemistry ,Ceramics and Composites ,Lithium - Abstract
Sn/SnO nanoparticles are incorporated in crumpled nitrogen-doped graphene nanosheets by a simple melting diffusion method. The resulting composite exhibits large specific capacity, excellent cycling stability and high rate capability as an anode for lithium-ion batteries.
- Published
- 2014
31. Study on Al2O3 Coated Carbon Sulfur Composite Materials for Lithium-Ion Battery
- Author
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Yu Si Liu, Chao Chao Ye, Lin Shi, Xing Hua Liang, and Tian Jiao Liu
- Subjects
Materials science ,Composite number ,General Engineering ,chemistry.chemical_element ,Electrolyte ,engineering.material ,Electrochemistry ,Sulfur ,Lithium-ion battery ,Surface coating ,chemistry ,Coating ,engineering ,Composite material ,Carbon - Abstract
Coated Al2O3thin film on the surface of the carbon sulfur composite material by liquid phase impregnation method, then made physical and chemical properties and electrochemical performance analysis on the coated carbon sulfur composite materials.Al2O3reduce the direct contact of the carbon sulfur composite materials and electrolyte, reducing the erosion of electrolyte on cathode materials, improve the cycle performance of carbon sulfur composite material. 0.1C in the 2.1~3.2v cycle 20 to 100 times. The capacity retention rate increased from 70% to 90% after coating.
- Published
- 2013
32. Comparison of Lini0.5Mn1.5O4 and LiMn2O4 for Lithium-Ion Battery
- Author
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Xing Hua Liang, Yu Si Liu, Chao Chao Ye, Lin Shi, Shuai Bo Zeng, and Tian Jiao Liu
- Subjects
Materials science ,Morphology (linguistics) ,Scanning electron microscope ,General Engineering ,Analytical chemistry ,Particle size ,Crystal structure ,High potential ,Lithium-ion battery ,Voltage - Abstract
The High Potential Material Lini0.5Mn1.5O4 was Synthesized via Solid-State Reaction.The Surface Morphology and Particle Size of the Sample were Observed by Scanning Electron Microscope(SEM).The Crystal Structure of the Sample was Collected and Analyzed through X-Ray Diffractometry(XRD).The Sample was Charaterized by Charge-Discharge Tests.Results Indicated that the Cycling Retention Rate was about 80%,after being Charge-Diacharged at a Rate of 0.1C in a Voltage of 3.45-4.77V for 10 Times.Compared with Limn2O4,LiNi0.5Mn1.5O4 has good cycle performance.Both of LiNi0.5Mn1.5O4 structure were space group of Fd3m.
- Published
- 2013
33. The Aluminum Brazing Pieces of Mechanical Performance Based on GRNN Neural Network
- Author
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Yu Si Liu, Lin Shi, Xing Hua Liang, and Xiao Ming Hua
- Subjects
Materials science ,Artificial neural network ,Metallurgy ,Alloy ,chemistry.chemical_element ,General Medicine ,Welding ,engineering.material ,law.invention ,Nonlinear system ,chemistry ,Aluminium ,law ,Approximation error ,Soldering ,engineering ,Brazing ,Composite material - Abstract
Aluminum and aluminum alloy were widely used in various industrial fields,the key to application is the reliable welding. In this thesis,LF21 aluminum alloy brazing materials were designed and prepared by Orthogonal experiment,and mechanical properties of the brazing specimen was tested. Based on the GRNN(Generalized Regression Neural Network),Nonlinear relationship modle of brazing material preparation parameters and mechanical properties of the weldment was established.The results show that the model has better stability.When smooth factor value is 0.1,the network approximation error and prediction error absolute value is 0.01%.It can be realized that an nonliner mapping between the aluminum alloy brazing preparation parameters and solder joint tensil strenth based on the Orthogonal test and can do better prediction of the weld mechanical properties,according to brazing material preparation parameters.
- Published
- 2013
34. Discovery of Breathing Phenomena in Continuously Rotating Detonation
- Author
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Yu-Si Liu, Y Li, J Wang, T.Y. Shi, Li Yangang, and Yuan Wang
- Subjects
Mass flux ,Chemistry ,business.industry ,time scales ,Detonation ,Diaphragmatic breathing ,Thrust ,General Medicine ,Structural engineering ,Mechanics ,Low Breathing ,Combustion ,Deep Breathing ,Continuously rotating detonation ,Combustor ,Breathing ,business ,Engineering(all) - Abstract
As is generally thought, continuously rotating detonation should keep going around the combustor regularly and has a fixed period. However, from the figures gotten by the data acquisition system, two kinds of breathing phenomena, Low Breathing and Deep Breathing, are discovered in the experiment. Actually they are caused by the changing mass flux, which stems from the pressure change in the combustor. The two kinds of breathing phenomena have different time scales and combustion mechanism. Reverse DDT is also discovered in one of the breathing phenomena. Since RDE is strong in thrust and high in efficiency, it has a great application foreground in the Aerospace Engineering.
- Published
- 2013
- Full Text
- View/download PDF
35. ANALYSIS OF THREE-DIMENSIONAL UPSETTING PROCESS BY THE RIGID-PLASTIC REPRODUCING KERNEL PARTICLE METHOD
- Author
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Xiaonong Chen, Songrui Yu, Yu-Si Liu, and J. Chen
- Subjects
Engineering drawing ,Materials science ,Kernel (statistics) ,Mathematical analysis ,Flow (psychology) ,Metals and Alloys ,Process (computing) ,Boundary (topology) ,Penalty method ,Boundary value problem ,Compression (physics) ,Industrial and Manufacturing Engineering ,Finite element method - Abstract
A meshless approach, called the rigid-plastic reproducing kernel particle method (RKPM), is presented for three-dimensional (3D) bulk metal forming simulation. The approach is a combination of RKPM with the flow theory of 3D rigid-plastic mechanics. For the treatments of essential boundary conditions and incompressibility constraint, the boundary singular kernel method and the modified penalty method are utilized, respectively. The arc-tangential friction model is employed to treat the contact conditions. The compression of rectangular blocks, a typical 3D upsetting operation, is analyzed for different friction conditions and the numerical results are compared with those obtained using commercial rigid-plastic FEM (finite element method) software Deform3D. As results show, when handling 3D plastic deformations, the proposed approach eliminates the need of expensive meshing and remeshing procedures which are unavoidable in conventional FEM and can provide results that are in good agreement with finite element predictions.
- Published
- 2006
36. Experimental Research on Transition Regions in Continuously Rotating Detonation Waves
- Author
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Jian-Ping Wang, Tian-Yi Shi, Yu-Si Liu, and Yuhui Wang
- Subjects
Physics::Fluid Dynamics ,Classical mechanics ,Chemistry ,Astrophysics::High Energy Astrophysical Phenomena ,Detonation ,Astrophysics::Solar and Stellar Astrophysics ,Flux ,Mechanics ,Combustion chamber ,Experimental research - Abstract
Continuously rotating detonation waves of thousands of Hz, indicating the merit of continuously rotating detonation waves that ignite only once to keep working, are experimentally gotten in the combustion chamber designed by Peking University. The steady continuously rotating detonation waves have jarless peak pressures and cycles microcosmicly, showing that during this stage, flux, pressure and temperature of working medium are steady. However, transition regions do exist between two groups of steady continuously rotating detonation waves. Related data of transition regions are fitted to find out the basic rule. The paper also figures out the velocity of ideal detonation waves by C-J theory, and obtains the cycle and number of continuously rotating detonation waves with experimental data.
- Published
- 2012
37. Incorporation of heterostructured Sn/SnO nanoparticles in crumpled nitrogen-doped graphene nanosheets for application as anodes in lithium-ion batteries.
- Author
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Fei-Hu Du, Yu-Si Liu, Jie Long, Qian-Cheng Zhu, Kai-Xue Wang, Xiao Wei, and Jie-Sheng Chen
- Subjects
- *
NANOPARTICLES , *GRAPHENE , *ANODES , *LITHIUM-ion batteries , *NANOCOMPOSITE materials , *ELECTROCHEMICAL analysis - Abstract
Sn/SnO nanoparticles are incorporated in crumpled nitrogen-doped graphene nanosheets by a simple melting diffusion method. The resulting composite exhibits large specific capacity, excellent cycling stability and high rate capability as an anode for lithium-ion batteries. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
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