检索结果-内蒙古大学图书馆

Fading behavior and wear mechanisms of c/c-Sic brake disc during cyclic braking

WEAR 2023年第1期526卷

作者： Hui, Yang Liu, Guimin Zhang, Qing Zhang, Yong Zang, Yan Wang, Sijie Shi, Ruidong Acad Army Armored Forces Dept Equipment Maintenance & Remfg Engn Beijing 100072 Peoples R China

In this work, the performances of c/c-Sic brake discs under extreme operating conditions, including cyclic high -temperature and emergency braking of heavy-duty tracked vehicles, were investigated. The friction interface evolution and anti-fading mechanism of c/c-Sic brake discs during cyclic braking were also revealed. The maximum temperature of the c/c-Sic brake discs contact surface during cyclic high-temperature braking reached 663.7 degrees c, while the maximum decay rate was only 9.55%. compared with the iron-based brake discs, the average coefficient of friction (cOF) of the c/c-Sic increased by 14.70% and the wear rate decreased by 306.68% after the 10th braking cycle. A "c + Sic + SiO2" continuous friction film generated during the late stage of braking slowed down the diffusion of oxygen into the matrix, resulting in an excellent performance of the brake discs at high temperatures. Furthermore, the average cOF of the c/c-Sic brake discs was maintained at 0.45-0.50 during cyclic emergency braking. When the friction film was not generated or was destroyed, the cOF mainly depended on the surface asperities. However, when the friction film was completely covered, the cOF decreased and tended to be stable and consistent, suggesting that c/c-Sic brake discs can provide a sufficient and stable braking force at different speeds.

关键词： c c-Sic brake Discs cyclic braking Friction Wear mechanism

来源：评论

学校读者我要写书评

暂无评论

c/MoS2@Ti3c2Tx composite flexible films for high performance supercapacitors

引用

ELEcTROcHIMIcA AcTA 2023年第1期441卷

作者： Ma, Yi Lu, Linghong Zhang, Yaopeng Zhou, Tao Nanjing Tech Univ Coll Chem Engn State Key Lab Mat oriented Chem Engn Nanjing 211816 Peoples R China

Two-dimensional (2D) Ti3c2Tx MXene has important potential applications in supercapacitor due to its high electrical conductivity, good hydrophilicity and abundant surface functional groups. It can be prepared into films of flexible electrochemical capacitors without adhesives. However, the self-stacking of Ti3c2Tx nanosheets seriously reduces their capacitance. Here, we developed a novel structure of the flexible material c/MoS2@Ti3c2Tx through facile physical mixing, three-dimensional c/MoS2 nanoflowers were successfully inserted between two-dimensional Ti3c2Tx layers. The self-stacking of MoS2 and Ti3c2Tx attenuates simultaneously. And these two materials form a particle-layer structure. At a current density of 0.5 A/g, the freestanding c/ MoS2@Ti3c2Tx film has an excellent specific capacitance of 410 F g-1, which is 2.6 times that of c/MoS2 and 1.9 times that of Ti3c2Tx, respectively. It remains in good condition after 5000 cycles at 10 A/g, demonstrating excellent long-life cycle stability. The improvement of electrochemical performance is attributed to the particlelayer structure, which effectively avoids the re-packing of Ti3c2Tx and greatly reduces the diffusion distance of electrolyte ions. Furthermore, the addition of c/MoS2 nanoflowers has no effect on the bending ability of MXene composite films. And The nano-flower-like structure of c/MoS2 provides high electric double layer capacitance performance. This study provides new ideas for Ti3c2Tx-based films in the field of energy storage and wearable devices.

关键词： Supercapacitor c MoS2 composite

来源：评论

学校读者我要写书评

暂无评论

Pd/c embedded crosslinked polystyrene fibers as an efficient catalyst for Heck reactions

引用

JOURNAL OF APPLIED POLYMER ScIENcE 2023年第4期140卷 e53363-e53363页

作者： Xie, Mali Peng, Kexin Luo, Yangyang Zhang, Qi Shao, Linjun Zhong, Shaofeng Zhou, Shujing Li, Jinjing Qi, chenze Shaoxing Univ Zhejiang Key Lab Alternat Technol Fine Chem Proc Shaoxing 312000 Zhejiang Peoples R China Zhejiang Ind Polytech Coll Dept Text Shaoxing 312000 Zhejiang Peoples R China Jiamusi Univ Sch Pharm Jiamusi Heilongjiang Peoples R China

Pd/c embedded polystyrene fibers were successfully prepared by electrospinning. The polystyrene molecules were then cross-linked by paraformaldehyde in sulfuric acid to improve the solvent resistance of composite fibers. SEM images conformed the preparation of uniform and smooth composite fibers. FT-IR spectra demonstrated that the polystyrene molecules inside fibers have been sulphonated and crosslinked. Heck reactions were used to evaluate the catalytic performance of these novel composite fibers. The catalysis results show that this composite fiber mat catalyzed Heck reactions could be evidently promoted by using preferred reducing alcohol agent and solvent. Under the optimized reaction conditions, this composite fiber mat could effectively catalyze the Heck reactions of aromatic iodides with n-butyl acrylate to afford the products with satisfied yields. Especially, compared with the particulate Pd/c catalyst, the separation and recycling of this fibrous catalyst from the reaction mixture were significantly improved due to the larger fibrous structure. At last, this fiber catalyst was successfully reused for eight times with little loss of initial catalytic activity, which was even better than the pristine Pd/c catalyst. Hence, embedment of particulate supported metal catalysts inside the crosslinked polystyrene fibers can effectively improve their catalytic performance and handiness.

关键词： electrospinning fiber heck reaction Pd c polystyrene

来源：评论

学校读者我要写书评

暂无评论

Elucidating prioritized factor for mainstream partial nitritation between c/N ratio and dissolved oxygen: Response surface methodology and microbial community shifts

引用

ENVIRONMENTAL RESEARcH 2023年第1期227卷 115748页

作者： cho, Kyungjin Lee, Sangji Jung, Jinyoung choi, Daehee Korea Inst Sci & Technol Ctr Water Cycle Res Seoul 02792 South Korea Univ Sci & Technol UST KIST Sch Div Energy & Environm Technol Seoul 02792 South Korea Yeungnam Univ Dept Environm Engn 280 Daehak Ro Gyongsan 38541 Gyeongbuk South Korea

Recently, c/N ratio is suggested as a promising control factor with dissolved oxygen (DO) achieving mainstream partial nitritation (PN);however, their combined effects on mainstream PN are still limited. This study evaluated the mainstream PN with respect to the combined factors, and investigated the prioritized factor affecting the community of aerobic functional microbes competing with NOB. Response surface methodology was performed to assess the combined effects of c/N ratio and DO on the activity of functional microbes. Aerobic heterotrophic bacteria (AHB) played the greatest role in oxygen competition among functional microbes, which resulted in relative inhibition of nitrite-oxidizing bacteria (NOB). The combination of high c/N ratio and low DO had a positive role in the relative inhibition of NOB. In bioreactor operation, the PN was successfully achieved at >= 1.5 of c/N ratio for 0.5-2.0 mg/L DO conditions. Interestingly, aerobic functional microbes outcompeting NOB were shifted with c/N ratio rather than DO, suggesting c/N ratio is more prioritized factor achieving mainstream PN. These findings will provide insights into how combined aerobic conditions contribute to achieve mainstream PN.

关键词： Mainstream partial nitritation Prioritized factor Relative NOB activity c N ratio Dissolved oxygen Aerobic functional microbes

来源：评论

学校读者我要写书评

暂无评论

Live-cell visualization of cytochrome c: a tool to explore apoptosis

引用

BIOcHEMIcAL SOcIETY TRANSAcTIONS 2021年第6期49卷 2903-2915页

作者： Pessoa, Joao Univ Lisbon Fac Med Inst Med Mol Joao Lobo Antunes Lisbon Portugal Univ Coimbra CNC Ctr Neurosci & Cell Biol CIBB Ctr Innovat Biomed & Biotechnol Coimbra Portugal

Apoptosis dysfunction is associated with several malignancies, including cancer and autoimmune diseases. Apoptosis restoration could be an attractive therapeutic approach to those diseases. Mitochondrial outer membrane permeabilization is regarded as the point of no return in the 'classical' apoptosis triggering pathway. cytoplasmic release of cytochrome c (cyt c), a mitochondrial electron transporter, is a prominent indicator of such critical step. Therefore, visualizing cyt c efflux in living cells is a convenient approach to address apoptosis triggering and monitor performance of apoptosis restoration strategies. Recent years have been prolific in the development of biosensors to visualize cyt c mitochondrial efflux in living cells, by fluorescence microscopy. These biosensors specifically detect endogenous, untagged cyt c, while showing efficient cellular uptake and reduced cell toxicity. A common aspect is their fluorescence quenching in the absence or presence of bound cyt c, resulting in two main biosensor types: 'turn ON' and 'turn OFF'. In some of these systems, fluorescence intensity of fluorophore-bound aptamers is enhanced upon cyt c binding. In others, cyt c binding to quantum dots quenches their fluorescence. In the present minireview, I describe these biosensors and briefly introduce some hypotheses that could be addressed using these novel tools.

关键词： aptamer cytochrome c fluorescence fluorescence quenching fluorophore live-cell microscopy

来源：评论

学校读者我要写书评

暂无评论

Mapping rRNA 2'-O-methylations and identification of c/D snoRNAs in Arabidopsis thaliana plants

引用

RNA BIOLOGY 2021年第11期18卷 1760-1777页

作者： Azevedo-Favory, J. Gaspin, c. Ayadi, L. Montacie, c. Marchand, V Jobet, E. Rompais, M. carapito, c. Motorin, Y. Saez-Vasquez, J. CNRS Lab Genome & Dev Plantes LGDP UMR 5096 F-66860 Perpignan France Univ Perpignan Via Domitia LGDP UMR5096 F-66860 Perpignan France Univ Fed Toulouse MIAT INRAE F-31326 Castanet Tolosan France Univ Fed Toulouse Genotoul Bioinformat Facil Bioinf INRAE Toulouse France Univ Lorraine Epitranscript & RNA Sequencing EpiRNA Seq Core Fa UMS2008 US40 INSERMIBSLorCNRS F-54000 Nancy France Univ Lorraine CNRS Nancy France Univ Strasbourg Inst Pluridisciplinaire Hubert Curien Lab Spectrometrie Masse BioOrgan UMR CNRS 7178 Strasbourg France

In all eukaryotic cells, the most abundant modification of ribosomal RNA (rRNA) is methylation at the ribose moiety (2MODIFIER LETTER PRIME-O-methylation). Ribose methylation at specific rRNA sites is guided by small nucleolar RNAs (snoRNAs) of c/D-box type (c/D snoRNA) and achieved by the methyltransferase Fibrillarin (FIB). Here we used the Illumina-based RiboMethSeq approach for mapping rRNA 2MODIFIER LETTER PRIME-O-methylation sites in A. thaliana col-0 (WT) plants. This analysis detected novel c/D snoRNA-guided rRNA 2MODIFIER LETTER PRIME-O-methylation positions and also some orphan sites without a matching c/D snoRNA. Furthermore, immunoprecipitation of Arabidopsis FIB2 identified and demonstrated expression of c/D snoRNAs corresponding to majority of mapped rRNA sites. On the other hand, we show that disruption of Arabidopsis Nucleolin 1 gene (NUc1), encoding a major nucleolar protein, decreases 2MODIFIER LETTER PRIME-O-methylation at specific rRNA sites suggesting functional/structural interconnections of 2MODIFIER LETTER PRIME-O-methylation with nucleolus organization and plant development. Finally, based on our findings and existent database sets, we introduce a new nomenclature system for c/D snoRNA in Arabidopsis plants.

关键词： 2ʹ -O-Methylation c D snoRNA rRNA fibrillarin nucleolin arabidopsis

来源：评论

学校读者我要写书评

暂无评论

High-temperature oxidation behavior of GTD-111 Ni-based superalloy with an ultrafine-grained surface at 900 °c

引用

cORROSION ScIENcE 2023年第1期212卷

作者： Pour-Ali, Sadegh Tavangar, Reza Akhtari, Faezeh Hejazi, Seyedsina Sahand Univ Technol Fac Mat Engn POB 51335-1996 Tabriz Iran Univ Siegen Fac Sci & Technol Chem & Struct Novel Mat POB 57076 Siegen Germany

The oxidation behavior of GTD-111 Ni-based superalloy with an ultrafine-grained surface (UFGS-GTD111) and its polycrystalline counterpart (cP-GTD111) in Ar + 20% O2 at 900 degrees c are comparatively investigated. Enhanced presence of high diffusivity paths (namely, GBs and dislocations) on the surface of UFGS-GTD111 significantly increases the diffusion of scale-former elements and oxygen anions toward the oxidation front. A three-layer oxide film (outer Ti-, intermediate cr-and inner-Al rich) rapidly form on the surface of UFGS-GTD111, and guarantees its better oxidation performance. Grain refinement reduces the critical concentration of Al for forming a virtually continuous alumina layer.

关键词： A Superalloys B TEM SEM X-ray diffraction c Oxidation

来源：评论

学校读者我要写书评

暂无评论

On the sulfation reaction of protective and transient oxides at 650 °c and its role in the low temperature hot corrosion mechanism

引用

cORROSION ScIENcE 2023年第1期218卷

作者： Malacarne, R. Mathieu, S. Siblani, M. Aranda, L. Knittel, S. Desgranges, c. Vilasi, M. Univ Paris Saclay Serv Corros & Comportement Mat Environm CEA F-91191 Gif Sur Yvette France Univ Lorraine CNRS IJL F-54000 Nancy France Safran Aircraft Engines Rue Henri Auguste Desbrueres F-91000 Evry France

MxOy-Na2SO4 (with M = Ni, cr, Fe, Al, Ti, Nb) and NiSO4-Na2SO4 mixtures were prepared and their reactivity was examined at 650 degrees c in air + SO2 (400 and 1000 ppm). The formation of a molten phase for NiSO4-Na2SO4 mixtures and the rapid sulfation of NiO in these conditions were demonstrated. NiO sulfation should be considered when explaining the Type II hot corrosion attacks. cr2O3, Fe2O3 and Al2O3 also react with the gas phase showing these oxides dissolved according to an acidic-fluxing mechanism in air + SO2/SO3 (400 and 1000 ppm) environments. Al2O3 is more soluble than cr2O3 in these conditions.

关键词： A Molten salts Nickel c Hot corrosion Selective oxidation

来源：评论

学校读者我要写书评

暂无评论

Accelerating innovations in c-H activation/functionalization through intricately designed magnetic nanomaterials: From genesis to applicability in liquid/regio/photo catalysis

引用

cATALYSIS cOMMUNIcATIONS 2023年 175卷

作者： Dutta, Sriparna Kumar, Prashant Yadav, Sneha Sharma, Ruchi Dubey Shivaprasad, Parimala Vimaleswaran, Karani S. Srivastava, Anju Sharma, Rakesh K. Univ Delhi Green Chem Network Ctr Dept Chem Delhi India Univ Delhi Hindu Coll Dept Chem Delhi 110007 India SRM Univ Dept Chem Sonepat Haryana India Career Coll Dept Chem Bhopal Madhya Pradesh India Univ Bath Dept Chem Engn Bath BA2 7AY England Univ Reading Dept Food & Nutr Sci Hugh Sinclair Unit Human Nutr Reading England Univ Reading Inst Food Nutr & Hlth IFNH Reading England Univ Delhi Green Chem Network Ctr Dept Chem Delhi 110007 India

Selective functionalization of highly inert and ubiquitous c-H bonds that would provide a ready access to synthetically valuable motifs has perplexed the chemists since long. Also, environmental benignity and economic viability have been the prime factors driving tremendous interest in c-H functionalization. This has led to many inspiring discoveries infuriating the development of potent catalytic systems that enable the facile replacement of the c-H bonds with conventional functional groups, allowing the construction of c-c, c-N, c-O, c-S, c-B and c -halogen bonds at both sp2 as well as sp3 centres. In fact, catalytic c-H functionalization strategies integrating the benefits of magnetic recovery have emerged as sustainable gateway for affording a diverse array of trans-formations. This review sheds light on the remarkable advancements witnessed in this area as a consequence of integrating the inherent magnetism of catalysts with the cutting-edge direct c-H functionalization strategy. Also, the promising future perspectives comprehensively covered in this review is anticipated to motivate the academic and industrial researchers, arousing their creativity for designing competent sustainable strategies to generate a plethora of pharmaceutically active molecules.

关键词： Magnetic nanocatalysts c H functionalization Heterocycles Sustainable synthesis Magnetic retrievability

来源：评论

学校读者我要写书评

暂无评论

Oxidation behavior of the AlN coatings on the TiAl alloy at 900 °c

引用

cORROSION ScIENcE 2023年 211卷

作者： Yang, Lanlan Gao, Fengyin Zhou, Zhaohui Jia, Yixuan Du, Yao Wang, Jinlong Qiao, Yanxin Zhu, Shenglong Wang, Fuhui Jiangsu Univ Sci & Technol Sch Mat Sci & Engn Zhenjiang 212003 Peoples R China State Power Investment Corp Hydrogen Energy Co Ltd Beijing 102209 Peoples R China Northeastern Univ Shenyang Natl Lab Mat Sci Shenyang 110819 Peoples R China Northeastern Univ Sch Mat Sci & Engn Shenyang 110819 Peoples R China Chinese Acad Sci Inst Met Res Lab Corros & Protect Shenyang 110016 Peoples R China

Oxidation behavior of the AlN coatings and the TiAl alloy is investigated at 900 degrees c. Results indicate that the application of the AlN coatings prepared by arc ion plating with different negative voltages on the TiAl alloy can improve its high temperature oxidation resistance. AlN in the coatings can be oxized to Al2O3 at 900 degrees c. After oxidation for 100 h, a protective Al2O3 scale without AlN is formed, and the Ti3Al/Ti2AlN/ Ti3Al interface is detected beneath that. The AlN coating with negative bias voltage 200 V exhibits higher oxidation resistance than others.

关键词： A Superalloys Metal coatings c Oxidation

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：