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Urchin-like MnO/c microspheres as high-performance lithium-ion battery anode

IONIcS 2021年第4期27卷 1423-1428页

作者： Zhang, Lei Shen, Lian Liu, Yangai Suo, Guoquan China Univ Geosci Sch Mat Sci & Technol Natl Lab Mineral Mat Beijing Key Lab Mat Utilizat Nonmetall Minerals & Beijing 100083 Peoples R China Shaanxi Univ Sci & Technol Sch Mat Sci & Engn Xian 710021 Peoples R China

Manganese oxide (MnO) is prospective as anode material for lithium-ion batteries (LIBs) due to its low insertion voltage and high reversible capacity. Here, urchin-like MnO microspheres with carbon coating (u-MnO/c) are synthesized through hydrothermal method, and its lithium storage performance is investigated. The unique urchin-like structures of u-MnO/c endow it high surface area which provides sufficient contact with electrolyte. The carbon coating can effectively suffer volume change of u-MnO during charge/discharge process. Meanwhile, the carbon coating can effectively improve the conductivity of u-MnO-based anode. Due to the above features, u-MnO/c delivers high initial capacity of 845 mAh g(-1), and an obvious activation process is observed at the beginning of the cycles thanks to the abundant invasion of the electrolyte into u-MnO/c. The large capacity of 723 mAh g(-1) can still be achieved after 80 cycles. This work provides a promising guide for designing high-performance LIBs electrode materials.

关键词： Lithium ion batteries MnO c composite Microsphere

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Elevated efficiency of c₃ photosynthesis in bamboo grasses: A possible consequence of enhanced refixation of photorespired cO₂

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GLOBAL cHANGE BIOLOGY BIOENERGY 2021年第6期13卷 941-954页

作者： Peixoto, Murilo M. Sage, Tammy L. Busch, Florian A. Pacheco, Haryel D. N. Moraes, Moemy G. Portes, Tomas A. Almeida, Rogerio A. Graciano-Ribeiro, Dalva Sage, Rowan F. Univ Fed Goias Programa Posgrad Biodiversidade Vegetal Inst Ciencias Biol Goiania Go Brazil Univ Toronto Dept Ecol & Evolutionary Biol 25 Willcocks St Toronto ON M5S 3B2 Canada Univ Birmingham Birmingham Inst Forest Res Sch Biosci Birmingham W Midlands England Univ Fed Goias Escola Agron Goiania Go Brazil Washington State Univ Sch Biol Sci Pullman WA 99164 USA

Bamboos are productive grasses that currently yield a high-quality wood and potentially an abundance of lignocellulose for bioenergy. All are c-3 grasses of warm habitats, where they are prone to significant photorespiratory inhibition and competitive suppression by c-4 grasses. Here, we investigate whether three bamboo species from the Brazilian cerrado (Dendrocalamus asper, Guadua angustifolia, and Guadua magna) exhibit unique adaptations that suppress photorespiratory costs and enhance photosynthetic efficiency. We evaluated photosynthetic efficiency of the bamboos and rice (Oryza sativa) by measuring c-*, the cO2 compensation point in the absence of mitochondrial respiration. At 25celcius, c-* averaged 2.81 Pa in each of the bamboo species, which is closer to a c-2 plant (2.71 Pa) than the c-3 plant rice (3.31 Pa). Assuming a chloroplast cO2 concentration of 200 mu mol mol(-1), this represents an 18% lower cost of apparent photorespiration in bamboo than rice. Light and transmission electronic microscopy of the bamboo leaves exhibited few organelles in the bundle and mestome sheath cells, and mesophyll (M) cells are deeply lobed with 99% of the cell periphery adjacent to intercellular air space covered by chloroplast and stromules. The chloroplast layer in bamboo M cells is thick, with mitochondria adjacent to or engulfed by chloroplasts. This arrangement slows cO2 efflux and facilitates refixation of photorespired cO2, which could explain the low c-* in the bamboos. The bamboos also had higher water use efficiency than rice, which may reflect efficient refixation of photorespired cO2.

关键词： Bambuseae c (*) c-3 photosynthesis cO2 refixation Dendrocalamus Guadua photorespiration water use efficiency

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Preparation of cluster-like SnS/SnO2/c nanoparticle with enhanced electrochemical performance for lithium-ion batteries

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IONIcS 2021年第5期27卷 1919-1927页

作者： Zhang, W. X. Wang, H. Zhao, P. He, c. Changan Univ Sch Mat Sci & Engn Xian 710064 Peoples R China Xi An Jiao Tong Univ Sch Mat Sci & Engn State Key Lab Mech Behav Mat Xian 710049 Peoples R China

A facile one-step solvothermal method to synthesize SnS/SnO2/c nanocluster particles has been reported. The nanocluster particles are derived from SnS2/c composite materials by adjusting pyrolysis temperature at 600 degrees c within 6 h under N-2 atmosphere. When assessed as anode materials for lithium-ion batteries (LIBs), SnS/SnO2/c nanocluster particles can deliver a high initial discharge capacity of 1978 mA h g(-1) and maintain high discharge capacity of 638 mA h g(-1) after 50 cycles at a current density of 100 mA g(-1), which is better than other pyrolysis products derived from SnS2/c materials. This work indicates that SnS/SnO2/c nanocluster particles may be a promising anode material for lithium-ion batteries and provides a simple method to construct ternary composite materials for energy storage.

关键词： Lithium-ion battery SnS SnO2 c anode Solvothermal method SnS2 c

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Effect of preset interfacial ZrB₂ particles on the microstructure and properties of c/c-AlSi composites

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JOURNAL OF cOMPOSITE MATERIALS 2021年第23期55卷 3203-3211页

作者： Feng, Wei Tang, chengwei Liu, Lei chen, Jian Zhang, Yang Yao, Xiyuan Zuo, Donglin Liu, Feilong Xian Technol Univ Sch Mat & Chem Engn Xian 710021 Peoples R China Northwestern Polytech Univ Sci & Technol Thermostruct Composite Mat Lab Xian Peoples R China

ZrB2 particles were preset to the c-AlSi interface to improve oxidation resistance of c/c preform and adjust the microstructure of the interpenetrated c/c-AlSi composite prepared through pressure infiltration of eutectic AlSi into a fiber fabric based porous c/c skeleton. Micro-morphology investigations suggested that the AlSi textures were changed from dendritic to petals-like state, and the nano to micro-scale ZrB2 particles were dispersed into AlSi and affected the distribution of Al and Si nearby carbon. Tests demonstrated that c/c-AlSi have slight lower density and thermal expansion coefficient, and higher original compressive strength, while c/c-ZrB2-AlSi composites presented an outstanding strength retention rate after thermal shock. Fracture and micro-morphology indicated that the influence of the preset ZrB2 to the interface of carbon and alloy greatly affected the generation and propagation of cracks, which determined the diverse compression behaviors of the composites before and after thermal shock.

关键词： c c Al matrix composite ZrB2 strength thermal shock

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Effect of Sic content on the mechanical behaviour of a three-dimensional needled c/Sic composite

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cERAMIcS INTERNATIONAL 2021年第17期47卷 25067-25073页

作者： Yin, Dezheng Deng, Yangfang Ma, Yuzhao Fan, Xiaomeng Beijing Inst Space Long March Vehicle Beijing 100076 Peoples R China AECC Sichuan Gas Turbine Estab Chengdu 610500 Sichuan Peoples R China Xian Univ Architecture & Technol Coll Mat Sci & Engn Xian 710055 Shaanxi Peoples R China Northwestern Polytech Univ Sci & Technol Thermostruct Composite Mat Lab Xian 710072 Shaanxi Peoples R China

In this study, the effect of the silicon carbide (Sic) matrix content on the mechanical behaviour of a threedimensional needled carbon fibre-reinforced Sic matrix composite (c/Sic) was investigated. The Sic matrix content was controlled by the infiltration time, and it can be divided into two stages for the evolution of matrix densification, leading to different mechanical responses. In the first stage, with an increase in the Sic matrix content from 12 to 39 vol%, the matrix was filled into a non-woven cloth, leading to an improvement in the loading efficiency of the fibre bundles. Thus, flexural strength and fracture toughness increased sharply from 54 to 218 MPa and 1.3-13.0 MPa m1/2, respectively. As the Sic matrix content increases to 59 vol% in the second stage, the flexural strength and fracture toughness increased to 256 MPa and 15.4 MPa m1/2, respectively. The infiltration ability of the Sic matrix into the non-woven cloth reached the threshold in this stage, and the Sic matrix filled the short-cut web layer, resulting in a slightly increasing tendency of strength and toughness.

关键词： Three-dimensional needled preform c Sic Strength and toughness Matrix densification

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Immobilization of c/ce-codoped ZnO nanoparticles on multi-walled carbon nanotubes for enhancing their photocatalytic activity

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JOURNAL OF DISPERSION ScIENcE AND TEcHNOLOGY 2021年第9期42卷 1311-1322页

作者： Thi Viet Ha Luu Minh Dai Luu Ngoc Nhiem Dao Van Thuan Le Hoai Thuong Nguyen Van Dat Doan Ind Univ Ho Chi Minh City Fac Chem Engn Ho Chi Minh City Vietnam Vietnam Acad Sci & Technol Inst Mat Sci Hanoi Vietnam Duy Tan Univ Ctr Adv Chem Inst Res & Dev Danang Vietnam Ind Univ Ho Chi Minh City Fac Elect Engn Technol Ho Chi Minh City Vietnam

c/ce-codoped ZnO nanoparticles immobilized onto multi-walled carbon nanotubes (c/ce-ZnO@MWcNT) were successfully fabricated via the hydrothermal method for degradation of methylene blue (MB) under visible light irradiation. The prepared c/ce-ZnO@MWcNT samples were characterized by XRD, XPS, FTIR, FE-SEM, EDX, BET, and diffuse reflectance spectroscopy. The obtained results indicated that the photocatalytic activity of all the MWcNTs-containing samples was higher than those of the bare ZnO and c/ce-codoped ZnO nanoparticles. Besides, the c/ce-ZnO@MWcNT composite with 50 wt% MWcNT showed the highest photocatalytic activity with the MB removal efficiency of 96.5% recorded within 90 min under visible light illumination using 1.0 g/L catalyst dosage at pH of 9 and MB concentration of 30 ppm. The degradation mechanism controlled by the charge transfer process in c/ce-ZnO@MWcNT composite was proposed and discussed in detail. In addition, the long-term-use ability of the photocatalyst was also evaluated through experiments conducted in continuous cycles.

关键词： c ce-ZnO@MWcNT photocatalytic activity methylene blue visible light multi-walled carbon nanotube

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考虑离子动力学的c4F7N放电模型及群参数研究

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中国电机工程学报 2024年

作者：郝迈张博雅刘沛琼李兴文电工材料电气绝缘全国重点实验室(西安交通大学)

目前针对c4F7N电子群参数的研究依赖于仅考虑电离和吸附过程的电子动力学模型，但有限的结果表明，当气压较高时，c4F7N存在电子解吸附等复杂的离子动力学过程，对气体放电与绝缘机制产生重要影响。该文首先在宽范围的约化场强和多个气... 详细信息

目前针对c4F7N电子群参数的研究依赖于仅考虑电离和吸附过程的电子动力学模型，但有限的结果表明，当气压较高时，c4F7N存在电子解吸附等复杂的离子动力学过程，对气体放电与绝缘机制产生重要影响。该文首先在宽范围的约化场强和多个气压条件下进行了c4F7N的脉冲汤逊实验，并通过对实验波形的详细分析，建立考虑离子动力学的c4F7N放电模型。接着，建立了考虑离子动力学的c4F7N电子崩时空发展理论模型，并结合遗传算法拟合电流波形，得到了c4F7N在60 Pa至5 kPa范围内的反应速率系数。最后，提出一种考虑离子动力学的有效电离速率系数计算方法，并重新评估了c4F7N的绝缘性能。

关键词：脉冲汤逊实验离子动力学电子群参数 c F N 临界击穿场强

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Microstructure and tribological properties of PIP-Sic modified c/c-Sic brake materials

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cERAMIcS INTERNATIONAL 2021年第11期47卷 15568-15579页

作者： Sun, Haodong Fan, Shangwu Wang, Le Ma, Xu Deng, Juanli cheng, Laifei Zhang, Litong Northwestern Polytech Univ Sci & Technol Thermostruct Composite Mat Lab Xian 710072 Shaanxi Peoples R China Changan Univ Sch Mat Sci & Engn Xian 710064 Shaanxi Peoples R China

A combination method of precursor infiltration and pyrolysis (PIP), chemical vapor infiltration (cVI) and liquid silicon infiltration (LSI) was proposed to prepare PIP-Sic modified c/c?Sic brake materials. The Sic ceramic matrix pyrolyzed by polymethysilane (PMS) homogeneously dispersed in the fiber bundles region, which improved the plough resistance of local c/c region and the wear resistance of c/c?Sic brake materials. When the braking speed rises to 28 m/s, the fluctuation range of friction coefficient was limited to 0.026. The linear wear rate of the as-prepared composites was could be -50% less than that of c/c?Sic, when the braking speed was above 15 m/s (for instance, the wear rate of 1.02 ?m/(side?cycle) at 28 m/s less than 2.02 ?m/(side?cycle) of traditional c/c? Sic). The fading ratio D of coF under wet conditions was -11%. The results showed that introducing PIP-Sic could stabilize the braking process and effectively prolong the service life of c/c?Sic brake materials.

关键词： c c?Sic Wear Precursor infiltration and pyrolysis Friction

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Acylation of non-specific phospholipase c4 determines its function in plant response to phosphate deficiency

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PLANT JOURNAL 2021年第6期106卷 1647-1659页

作者： Yang, Bao Zhang, Ke Jin, Xiong Yan, Jiayu Lu, Shaoping Shen, Qingwen Guo, Lei Hong, Yueyun Wang, Xuemin Guo, Liang Huazhong Agr Univ Natl Key Lab Crop Genet Improvement Wuhan 430070 Peoples R China Univ Missouri Dept Biol St Louis MO 63121 USA Donald Danforth Plant Sci Ctr St Louis MO 63132 USA

Non-specific phospholipase c (NPc) is involved in plant growth, development and stress responses. To elucidate the mechanism by which NPcs mediate cellular functions, here we show that NPc4 is S-acylated at the c terminus and that acylation determines its plasma membrane (PM) association and function. The acylation of NPc4 was detected using NPc4 isolated from Arabidopsis and reconstituted in vitro. The c-terminal cys-533 was identified as the S-acylation residue, and the mutation of cys-533 to Ala-533 in NPc4 (NPc4(c533A)) led to the loss of S-acylation and membrane association of NPc4. The knockout of NPc4 impeded the phosphate deficiency-induced decrease of the phosphosphingolipid glycosyl inositol phosphoryl ceramide (GIPc), but introducing NPc4(c533A) to npc4-1 failed to complement this defect, thereby supporting the hypothesis that the non-acylated NPc4(c533A) fails to hydrolyze GIPc during phosphate deprivation. Moreover, NPc4(c533A) failed to complement the primary root growth in npc4-1 under stress. In addition, NPc4 in Brassica napus was S-acylated and mutation of the S-acylating cysteine residue of ***4 led to the loss of S-acylation and its membrane association. Together, our results reveal that S-acylation of NPc4 in the c terminus is conserved and required for its membrane association, phosphosphingolipid hydrolysis and function in plant stress responses.

关键词： Arabidopsis thaliana Brassica napus non‐ specific phospholipase c S‐ acylation membrane association GIPc

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carbon-bridged atomically dispersed platinum on MOF-derived ZnO/c for selective photocatalytic oxidation of NO into Nitrates and Nitrites

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cARBON 2023年 214卷

作者： Hu, Lizhen Liu, Jiayou Huang, Xiaoxiang Nie, Qianqian Liu, Penglei Tan, Zhongchao Yu, Hesheng China Univ Min & Technol Sch Chem Engn & Technol Xuzhou 221116 Jiangsu Peoples R China Univ Waterloo Dept Mech & Mechatron Engn 200 Univ Ave West Waterloo ON N2L 3G1 Canada Tsinghua Univ Dept Energy & Power Engn Beijing 100084 Peoples R China Univ Waterloo Dept Mech & Mechatron Engn Waterloo ON N2L 3G1 Canada

Using nanoclusters and single atoms with unique activity to replace nanoparticles is a promising strategy to enhance catalyst activity. However, stable loading of nanoclusters and single atoms remain a challenge. This paper reports atomically dispersed Pt bridged with metal-organic framework (MOF)-derived ZnO/c through carbon atoms (Pt-ZnO/c), by impregnation combined with calcination, for photocatalytic oxidation of NO. The MOF-derived ZnO/c has a larger specific surface area than pure ZnO. The presence of c enhances the visible light absorption, promotes the migration of photogenerated carriers, and more importantly facilitates the stabilization of Pt single atoms through Pt-c interactions. The Pt species present in the Pt-ZnO/c catalysts in the form of single atoms and nanoclusters. The Pt-ZnO/c catalysts show high NO conversion rates and selectivity towards NO3 /NO2  ions formation. Specifically, the NO conversion rate of 81.9% is much higher than those of ZnO/c (31.4%) and Pt nanoparticles loaded ZnO/c (Pt NPs-ZnO/c, 58.6%). In addition, the selectivity of NO3 /NO2  (i. e., 98.6%) formation over the Pt-ZnO/c catalyst is much higher than that of NO2 (i.e., 1.4%). Furthermore, the photocatalysis tests and ESR results suggest that the Pt single atoms and nanoclusters can enhance the oxidation of NO by promoting the production of O2 & BULL;- and OH & BULL;. The DFT results also reveal that single Pt atoms promote the adsorption of O2 and H2O to form O2 & BULL;- and OH & BULL;. More importantly, OH & BULL;can promote the selective oxidation of NO to NO3  /NO2  ions. In addition, the projected density of states of single Pt atoms loaded on the ZnO/c catalysts show that the presence of c atom bridge favors the stability of single Pt atoms because of the interaction between c and Pt atoms. This work provides a new strategy for the design of single-atom-loaded metal oxide catalysts.

关键词： Photocatalytic oxidation Single Pt atoms Nanoclusters ZnO c Selective NO oxidation

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