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Ti-Fe-Si/c composites as anode materials for high energy li-ion batteries

ENERGY SOURcES PART A-REcOVERY UTILIZATION AND ENVIRONMENTAL EFFEcTS 2022年第2期44卷 5154-5171页

作者： Nuhu, Bage Alhamdu Adun, Humphrey Bamisile, Olusola Mukhtar, Mustapha Southwest Petr Univ Sch Chem & Chem Engn Chengdu Peoples R China Cyprus Int Univ Energy Syst Engn Dept Mersin 10 Nicosia Turkey Chengdu Univ Technol Coll Nucl Technol & Automat Engn Chengdu Sichuan Peoples R China Guangdong Univ Petrochem Technol Sch Econ & Management Maoming Chinese Provinc Peoples R China

In this study, Ti-Fe-Si composites were prepared by one step ball-milling method as anode materials for Li-ion batteries. The effects of ball-milling speed and time were studied by X-ray diffraction, electron microscopy, and Fe-57 Mossbauer spectroscopy. changes in the composition and microstructure of the composites were observed and related to the electrochemical performance. Increasing ball-milling speed led to the formation of FeSix alloys that reduced the specific capacity while increasing the ball-milling time improved the particle size morphology and homogeneity. Discharge/charge profiles for the first two cycles were carried out at 0.05c current rate (1c = 1260 mAh.g(-1)for Li3.75Si). The first discharge for Ti-Fe-Si showed a LixSi reaction plateau of 1100 mAh.g(-1), which were reversible and yielded columbic efficiency (cE) 77% and 90% in the first and second cycles, respectively. This capacity plateau indicated the insertion of about 3.25 Li into silicon. For the composite containing an additional 10% carbon SP, the theoretical capacity was about 1130 mAh.g(-1), the discharge curve showed that the first discharge plateau reaches 1030 mAh.g(-1) corresponding to 3.5 Li with the first cE was about 85%, and 98% for the second cycle. The addition of carbon to Ti-Fe-Si-c played a key role in capacity retention. The best results were obtained for the composite Fe/Ti/Si (1:1:2) with 10 wt% of carbon, ball-milled at 500 rpm for 48 hours. The specific capacities were about 900 mAh.g(-1) at c/5 and 700 mAh.g(-1) at 1c (c = 1200 mAg(-1)) with a capacity retention of about 90% for 100 cycles.

关键词： Ti-Fe-Si c Li-ion batteries ball milling anode capacity discharge charge

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Microstructure and mechanical properties of the c/c composite and Nb joints brazed with an active Ag-based filler metal

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cERAMIcS INTERNATIONAL 2022年第7期48卷 9621-9630页

作者： Zheng, K. Yang, Z. W. Wang, Y. Wang, D. P. Tianjin Univ Sch Mat Sci & Engn Tianjin Key Lab Adv Joining Technol Tianjin 300072 Peoples R China Minist Educ Key Lab Adv Ceram & Machining Technol Tianjin 300350 Peoples R China

An active Ag-based filler metal, containing trace alloy elements of Al, cu and Ti, was successfully applied to braze c/c composite and Nb. The microstructure and formation mechanism of the c/c composite and Nb brazed joint were investigated in this study. Moreover, the influence of brazing parameters on microstructural evolution and mechanical properties of brazed joints was evaluated. The typical interfacial microstructure of the joint obtained at 950 degrees c for 600 s was c/c/Tic + Alcu2Ti/Ag(s, s) + Alcu2Ti + particle cu/Alcu2Ti + AlcuTi + (Ti, Nb)3Al + Nb(Ti)/Nb. The dispersive Alcu2Ti phase was uniformly distributed in the Ag matrix, which was a beneficial structure for the brazed joint. The shear strength of the brazed joint was sensitive to the brazing temperature and holding time, which was closely related to the Tic layer bordering the c/c composite. The thickness of the Tic layer first increased as temperature increased to 950 degrees c, and then decreased when temperature reached 970 degrees c. The carbon fiber eroded by the filler at 970 degrees c entered to the brazing seam and reacted with Ti, resulting the reduction of the thickness of Tic, thus damaging the strength of the joint. With extension of holding time from 300 s to 1200 s, the interface reaction became more sufficient. Therefore, the thickness of the Tic layer increased. However, at 1200 s, the over-thick Tic broke the c/c substrate because of the mismatch of coefficient of thermal expansions. The maximum shear strength of the joint (950 degrees c/600 s) reached 55 MPa at room temperature and 35 MPa tested at 550 degrees c.

关键词： c c composite Braze Mechanical properties Microstructures

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Ordered Element Distributed c3N Quantum Dots Manipulated crystallization Kinetics for 2D csPbI3 Solar cells with Ultra-High Performance

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SMALL 2022年第15期18卷 2108090-2108090页

作者： Li, Zhizai Yang, Siwei Ye, caichao Wang, Gang Ma, Bo Yao, Huanhuan Wang, Qian Peng, Guoqiang Wang, Qiang Zhang, Hao-Li Jin, Zhiwen Lanzhou Univ Sch Phys Sci & Technol Lanzhou 730000 Peoples R China Lanzhou Univ Key Lab Magnetism & Magnet Mat MoE Lanzhou 730000 Peoples R China Chinese Acad Sci Shanghai Inst Microsyst & Informat Technol State Key Lab Funct Mat Informat Lab Graphene Mat & Applicat Shanghai 200050 Peoples R China Univ Chinese Acad Sci Coll Mat Sci & Optoelect Technol Beijing Peoples R China Southern Univ Sci & Technol Acad Adv Interdisciplinary Studies Shenzhen 518055 Guangdong Peoples R China Southern Univ Sci & Technol Guangdong Prov Key Lab Computat Sci & Mat Design Shenzhen 518055 Guangdong Peoples R China Ningbo Univ Sch Phys Sci & Technol Dept Microelect Sci & Engn Ningbo 315211 Peoples R China Lanzhou Univ State Key Lab Appl Organ Chem Lanzhou 730000 Peoples R China Lanzhou Univ Key Lab Special Funct Mat & Struct Design Lanzhou 730000 Peoples R China Lanzhou Univ Coll Chem & Chem Engn Lanzhou 730000 Peoples R China

Two-dimensional (2D) csPbI3 is developed to conquer the phase-stability problem of csPbI3 by introducing bulky organic cations to produce a steric hindrance effect. However, organic cations also inevitably increase the formation energy and difficulty in crystallization kinetics regulation. Such poor crystallization process modulation of 2D csPbI3 leads to disordered phase-arrangement, which impedes the transport of photo-generated carriers and worsens device performance. Herein, a type of c3N quantum dots (QDs) with ordered carbon and nitrogen atoms to manipulate the crystallization process of 2D csPbI3 for improving the crystallization pathway, phase-arrangement and morphology, is introduced. combination analyses of theoretical simulation, morphology regulation and femtosecond transient absorption (fs-TA) characterization, show that the c3N QDs induce the formation of electron-rich regions to adsorb bulky organic cations and provide nucleation sites to realize a bi-directional crystallization process. Meanwhile, the quality of 2D csPbI3 film is improved with lower trap density, higher surface potential, and compact morphology. As a result, the power conversion efficiency (PcE) of the optimized device (n = 5) boosts to an ultra-high value of 15.63% with strengthened environmental stability. Moreover, the simple c3N QDs insertion method shows good universality to other bulky organic cations of Ruddlesden-Popper and Dion-Jacobson, providing a good modulation strategy for other optoelectronic devices.

关键词： 2D csPbI (3) c N-3 crystallization kinetics phase management

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Waste biomass derived carbon supported Mo2c/c composite materials for heavy metal adsorption and hydrogen evolution reaction

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MATERIALS TODAY cOMMUNIcATIONS 2022年 31卷

作者： Ding, Jun He, Wenzhi Yu, chao Liu, Zhenglong Deng, chengji Zhu, Hongxi Wuhan Univ Sci & Technol State Key Lab Refractories & Met Wuhan 430081 Peoples R China

Application of waste biomass resources in heavy metal adsorption and new energy development is of great significance to improving environmental pollution and the adjustment of energy structure. For this purpose, we designed a simple method for preparing porous Mo2c/c composite materials based on resource-rich biomass carbon (derived from waste pine wood) and ammonium molybdate, and successfully applied it to the above field. The effects of holding time and sintering temperature on the phase compositions and morphological structures of samples were investigated, and the heavy adsorption capacity (cr(III)) and hydrogen evolution reaction of composite materials were also studied. The results showed that porous biomass Mo2c/c composite materials had significantly higher oxidation resistance, and more prominent pore structure as compared to the pretreated biomass carbon. In addition, porous biomass Mo2c/c composite materials showed excellent adsorption performance for heavy metal cr(III) and catalytic hydrogen evolution reaction performance, its adsorption capacity and Tafel slope were 43.2 mg/g and 123.9 mV/dec, respectively.

关键词： Porous biomass Mo (2) c c Biomass carbon Heavy metal adsorption Hydrogen evolution reaction cr(III)

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虎皮楠生物碱Daphniglaucin c的AB环系合成

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有机化学 2025年第3期45卷 925-932页

作者：张晓锋 Aggeliki Roumana 毛海康徐晶哈尔滨工业大学化学与化工学院哈尔滨150001 南方科技大学化学系、深圳格拉布斯研究院、广东省催化化学重点实验室、深圳市小分子药物发现与合成重点实验室广东深圳518055

从廉价易得的原料开始, 通过铑催化[4+3]环加成以及Heck偶联等关键反应, 高效简洁地得到了Daphniglaucin c虎皮楠生物碱的AB环系, 同时, 也尝试了利用黄氏酰胺活化增环反应进行c环构筑的探索. 本工作为Daphniglaucin c型虎皮楠生物碱的... 详细信息

从廉价易得的原料开始, 通过铑催化[4+3]环加成以及Heck偶联等关键反应, 高效简洁地得到了Daphniglaucin c虎皮楠生物碱的AB环系, 同时, 也尝试了利用黄氏酰胺活化增环反应进行c环构筑的探索. 本工作为Daphniglaucin c型虎皮楠生物碱的全合成提供了一条新的思路.

关键词：虎皮楠生物碱 Daphniglaucin c 铑催化环加成 Heck偶联全合成

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cyclic ablation behavior and microstructure evolution of multi-layer coating on c/c composites under oxyacetylene torch

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cERAMIcS INTERNATIONAL 2022年第15期48卷 21709-21716页

作者： Zhang, Jian Zhang, Yulei Zhang, Tien chen, Ruicong Zhu, Xiaofei Northwestern Polytech Univ Shaanxi Key Lab Fiber Reinforced Light Composite State Key Lab Solidificat Proc Xian 710072 Peoples R China Gen Design Dept Beijing Mech & Elect Engn Beijing 100089 Peoples R China

The cyclic ablation resistance of coated carbon/carbon (c/c) composites play crucial roles in their further engineering applications and development due to the cyclic ablation environment accompanied by rapid heating and cooling and high-speed heat flow scouring, which can reflect the performance stability of the coating. In this research, a (Sic/Hfc)4/Sic (SHS) multi-layer coating was prepared on c/c composites. compared with single layer (Sic and Hfc coating) coated sample, the mass and linear ablation rate of SHS coated sample after three ablation cycles (60 s x 3) were only 0.64 mg/s and 0.53 mu m/s, respectively. This is mainly because the introduction of many interfaces inhibits the propagation of cracks, the irregular cracks region only exists in the outer layer. Besides, the oxide layer with dense structure was formed near the c/c substrate, which could prevent oxygen from penetrating into the coating and continue to play a protective role.

关键词： c c composites Multilayer coatings cyclic ablation Hfc and Sic coating

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Ablation behaviors of Sic nanowire-reinforced Zrc-Sic coating-matrix integrated c/c composites with different ratios of precursors

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JOURNAL OF THE EUROPEAN cERAMIc SOcIETY 2022年第15期42卷 6774-6784页

作者： Tian, Xinfa Yang, Li Li, Bo Li, Hejun Shi, Xiaohong Lin, Hongjiao Northwestern Polytech Univ Shaanxi Prov Key Lab Fiber Reinforced Light Compos Xian 710072 Shaanxi Peoples R China Northwestern Polytech Univ Sch Mech Civil Engn & Architecture Xian Peoples R China

A novel method to prepare a coating on the c/c composite is discussed. The precursor infiltration pyrolysis method is usually applied to prepare interior ceramic matrix, thus Sic nanowires that can absorb the surficial precursor are added to prepare surficial ceramics. The method accomplishes the integration of the coating and the matrix so that no coating peels off after ablation. Moreover, the material with a Zrc/Sic precursor ratio of 5:1 (Z5S1), whose mass and linear rates are 0.47 mg/s and 0.95 mu m/s, exhibits the highest overall resistance to ablation. The results demonstrate that higher Zrc content and more uniform phase distribution are beneficial to keep ZrO2 in solid and form a denser and firmer oxide layer, which is more effective in improving the ablation resistance of the c/c composite.

关键词： c Ablation Precursor infiltration pyrolysis coating-matrix integration

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Stochastic fatigue life prediction in c/Sic composites at elevated temperature by micromechanics-based damage model

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PROcEEDINGS OF THE INSTITUTION OF MEcHANIcAL ENGINEERS PART L-JOURNAL OF MATERIALS-DESIGN AND APPLIcATIONS 2022年第9期236卷 1699-1714页

作者： Li, Longbiao Nanjing Univ Aeronaut & Astronaut Coll Civil Aviat 29 Jiangjun Ave Nanjing 211106 Peoples R China

In this paper, a micromechanical approach is developed to predict the fatigue life and fracture process in different c/Sic composites subjected to different stochastic fatigue loading spectrums at elevated temperatures. Three types of stochastic fatigue load spectrums are considered in the fatigue life prediction at elevated temperature, that is, constant, increasing, and decreasing stochastic stress with cycles. Stress distribution between intact and broken fibers and the broken fibers fraction under stochastic fatigue loading spectrum are determined using the Global Load Sharing criterion considering multiple fatigue damage mechanisms at elevated temperatures. A new damage parameter of fatigue life degradation rate is developed to characterize the effect of stochastic loading on fatigue damage and fracture in c/Sic composites. Relationships between stochastic fatigue loading spectrum, broken fibers fraction, fatigue life, and fatigue life degradation rate in different c/Sic composite are established. Effects of stochastic fatigue loading spectrum type, stress level, and testing temperature on fatigue life degradation rate are discussed. The fatigue life degradation rate is very sensitive to the fiber preform, loading sequence, and testing temperature.

关键词： ceramic-matrix composites (cMcs) c Sic fatigue life S - N curves stochastic fatigue load spectrum micromechanical

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Effect of h-BN addition on friction and wear properties of c/c-Sic composites fabricated by LSI

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INTERNATIONAL JOURNAL OF APPLIED cERAMIc TEcHNOLOGY 2022年第1期19卷 108-118页

作者： Niu, Zi-bo chen, Fu Xiao, Peng Li, Zhuan Pang, Lang Li, Yang Cent South Univ State Key Lab Powder Met Changsha 410083 Peoples R China Cent South Univ Natl Key Lab Sci & Technol Natl Def High Strength Changsha Peoples R China

Hexagonal boron nitride (h-BN) has excellent oxidation resistance, self-healing function, and self-lubricating properties, which can significantly improve the oxidation resistance of c/c-Sic composites in low or medium temperature condition and affect their tribological properties and mechanisms. In this work, c/c-Sic and c/c-BN-Sic composites were prepared by the same molding, carbonization and liquid silicon infiltration (LSI) processes and the influences of h-BN addition on their microstructure, tribological properties, and mechanisms were investigated. h-BN addition can promote the formation of friction film and reduce the oxidation wear of the composites. compared with c/c-Sic composites, due to more lubricant components and different matrix structure, the c/c-BN-Sic composite shows lower wear rate (reduced by 53%) and moderate rather than too high coefficient of friction (coF) and its coF is less influenced by braking velocity. Moreover, the friction process is more stable and does not appear clamping stagnation phenomenon in high braking speed condition.

关键词： c c-Sic composite h-BN modification microstructure tribological properties

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Static data-flow analysis for software product lines in c Revoking the preprocessor's special role

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AUTOMATED SOFTWARE ENGINEERING 2022年第1期29卷 35页

作者： Schubert, Philipp Dominik Gazzillo, Paul Patterson, Zach Braha, Julian Schiebel, Fabian Hermann, Ben Wei, Shiyi Bodden, Eric Paderborn Univ Paderborn Germany Univ Cent Florida Orlando FL 32816 USA Univ Texas Dallas Dallas TX USA Fraunhofer IEM Paderborn Germany Tech Univ Dortmund Dortmund Germany

Many critical codebases are written in c, and most of them use preprocessor directives to encode variability, effectively encoding software product lines. These preprocessor directives, however, challenge any static code analysis. SPLlift, a previously presented approach for analyzing software product lines, is limited to Java programs that use a rather simple feature encoding and to analysis problems with a finite and ideally small domain. Other approaches that allow the analysis of real-world c software product lines use special-purpose analyses, preventing the reuse of existing analysis infrastructures and ignoring the progress made by the static analysis community. This work presents VarAlyzer, a novel static analysis approach for software product lines. VarAlyzer first transforms preprocessor constructs to plain c while preserving their variability and semantics. It then solves any given distributive analysis problem on transformed product lines in a variability-aware manner. VarAlyzer 's analysis results are annotated with feature constraints that encode in which configurations each result holds. Our experiments with 95 compilation units of OpenSSL show that applying VarAlyzer enables one to conduct inter-procedural, flow-, field- and context-sensitive data-flow analyses on entire product lines for the first time, outperforming the product-based approach for highly-configurable systems.

关键词： Inter-procedural static analysis Software product lines Preprocessor LLVM c c plus plus

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