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Hydrogen-induced cracking behaviors of Incoloy alloy 825

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International Journal of Minerals,Metallurgy and Materials 2010年第1期17卷 58-62页

作者： yong-jin yang Ke-wei Gao Chang-feng Chen School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China Department of Materials Science and Technology China University of Petroleum Beijing 102249 China

The effect of hydrogen on the fractttre behaviors of Incoloy alloy 825 was investigated by means of slow strain rate testing （SSRT） Hydrogen was introduced into the sample by electrochemical charging. The results show that surface microcracks form gradually during ag- ing at room temperature when desorption of hydrogen takes place after hydrogen charging at a current density of 5 mA/cm^2 for 24 h. SSRT shows that the increase of ductility loss is significantly obvious as the hydrogen charging current density increases. Scanning electron microscopy （SEM） images reveal ductile fracture in the pre-charged sample with low current densities, while the fracture includes small quasi-cleavage regions and tends to be brittle fracture as the hydrogen charging current density increases to 5 mA/cm^2.

关键词： Incoloy alloy hydrogen-induced cracking diffusible hydrogen slow strain rate testing

Hlder Continuity for a Class of Strongly Degenerate Schrdinger Operator Formed by Vector Fields

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Acta Mathematicae Applicatae Sinica 2013年第2期29卷 281-288页

作者： yong-yang jin Jie-lin L Rong-fei LIN Department of Applied Mathematics Zhejiang University of Technology Zhejiang Vocational College of Commerce Department of Mathematics Taizhou University

In this paper we obtain the H61der continuity property of the solutions for a class of degenerate Schr6dinger equation generated by the vector fields：∑i,j=1^m Xj^＊（aij（x）Xiu）＋bXu=uu=0,where X = {X1,.-. ,Xm} is a family of C^∞ vector fields satisfying the H6rmander condition, and the lower order terms belong to an appropriate Morrey type space.

关键词： Hoe1der continuity degenerate SchrSdinger operator green function

Synthesis of Iron Chlorophyllins and Their Catalytic Performance for Aerobic Oxidation of Cyclohexene

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Chemical Research in Chinese Universities 2013年第3期29卷 526-532页

作者： LIU Xiao-hong LI yong-jin yang Wei-jun GUO Can-cheng College of Chemistry and Chemical Engineering Hunan University Changsha 410082 P. R. China

A series of iron（III） chlorophyllins was prepared from silkworm excrement crude chlorophyll extract as a raw material. Aerobic oxidation of cyclohexene by using the prepared iron（III） chlorophyllins as biomimetic catalysts was studied under atmospheric pressure in the absence of reducing agent and solvent. The results indicate that chloro- phyll iron porphyrins have better catalytic performance than the industrial-applied iron tetraphenylporphyrin and cobalt tetraphenylporphyrin, and possess a higher selectivity for 2-cyclohexen-1-one. The smaller the polarity of iron（III） chlorophyllin＇s ligand is, the easier the catalytic oxidation of cyclohexene will be. Esterification products of iron（III） chlo- rophyllins can catalyze the oxidation of cyclohexene better than non-esterified iron（III） chlorophyllins, and therefore show a higher conversion of cyclohexene and a higher selectivity for 2-cyclohexen-l-one than the non-esterified ones. Among the six synthesized iron（III） chlorophyllin catalysts, iron（III） methyl-pyropheophorbide-a is the best biomimetic catalyst for the highest conversion of cyclohexene. The influences of catalyst＇s substituent, polarity and ring structure on the catalytic performance were discussed. The catalytic performance of iron（III） chlorophyllins improves with decreasing polarity, increasing conjugated degree of porphyrin＇s ring or enhancing chlorophyllins＇ stability. Possible mechanism of cyclohexene aerobic oxidation catalyzed by iron（III） chlorophyllins was also discussed.

关键词： Chlorophyll Iron chlorophyltin Air Cyclohexene Catalytic oxidation

Late Paleozoic to early Mesozoic volcanic-sedimentary history of the southeastern margin of the Central Asian Orogenic Belt: Timing of uplift of the Inner Mongolia paleo-uplift

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Science China Earth Sciences 2025年第1期68卷 297-309页

作者： Wenxing HAO jin-Hui yang Guang ZHU State Key Laboratory of Lithospheric Evolution Institute of Geology and Geophysics Chinese Academy of Sciences School of Resource and Environmental Engineering Hefei University of Technology

The Kulun region is located in the eastern Bainaimiao arc belt on the southeastern margin of the Central Asian Orogenic Belt(CAOB), adjacent to the North China Craton(NCC) to the south. This region records the closure of the PaleoAsian Ocean during the Paleozoic to early Mesozoic and is key to study the tectonic evolution of the northern margin of the *** conducted zircon U-Pb geochronology and Hf isotope analysis of volcanic-sedimentary and intrusive rocks in the Kulun region. The volcanic-sedimentary rocks were previously assigned an early Carboniferous age, but include volcanic rocks with ages of 267–266 Ma and sedimentary rocks with youngest detrital zircon age peaks of 265–244 Ma, which were intruded by a granite with an age of 242 Ma. This indicates that these rocks are actually middle Permian to Middle Triassic in age(267–242Ma) and correspond to the Qingfengshan and Liujiagou formations. Moreover, two volcanic rock samples have high εHf(t) values(+1.6 to +16.1) and relatively young two-stage Hf model ages(1095–327 Ma), indicating their sources associated with the CAOB. The age spectra and Hf isotopic characteristics of detrital zircons from the sedimentary rocks suggest that, during the middle Permian to Middle Triassic, the sedimentary provenance in the Kulun region was mainly the CAOB. However, by the Early Jurassic, the provenance changed to the NCC(i.e., the Inner Mongolia Paleo-uplift, IMPU). This result, combined with the development of a series of conglomerates on the northern margin of the NCC in the Late Triassic(i.e., Xingshikou, Xiaoyingzi,and Xiaohekou formations), indicates the Kulun region experienced an abrupt change in paleogeography during the Late Triassic, with the IMPU undergoing significant uplift and thus becoming the main sediment source in the Kulun region. Based on the Late Triassic alkaline igneous belt(235–215 Ma) in the IMPU, we speculate that this uplift was caused by detachment of the southward-subducting Paleo-Asian oceanic

关键词： Central Asian Orogenic Belt the North China Craton Zircon geochronology Hf isotopes Inner Mongolia Paleo-uplift

Broadband low-frequency sound absorption of multifunctional composite metastructure

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Science China Technological Sciences 2025年

作者： Yilong yang Shanshan LIU Yan LI Tong GAO yongdong PAN yong LI Yabin jin School of Aerospace Engineering and Applied Mechanics Tongji University Institute of Acoustics School of Physics Science and Engineering Tongji University Shanghai Institute of Aircraft Mechanics and Control State International Joint Research Center of Aerospace Design and Additive Manufacturing Northwestern Polytechnical University Shanghai Key Laboratory of Intelligent Sensing and Detection Technology School of Mechanical and Power Engineering East China University of Science and Technology

In this study, we fabricated multifunctional metastructures from carbon fiber-reinforced plastic composites using additive manufacturing technology. These metastructures are characterized by their lightweight, load-bearing capacity, and broadband low-frequency sound absorption properties. The metastructure consists of 36 unit cells, and non-local coupling mechanism was considered for designing the sound absorption performance. We developed an acoustic impedance theory tailored for the metastructure, facilitating an analysis of thermal and viscous dissipation mechanisms. It is proven theoretically and experimentally that the proposed composite metastructure can achieve a noise reduction with an average sound absorption coefficient greater than 0.9 across frequencies in the rage of 330–1500 Hz. We also studied the metastructure’s quasi-static and cyclic compression performance, confirming its efficient absorption capabilities after cyclic compression. The proposed design and additive manufacturing method for composite metastructures provides a novel pathway for creating lightweight, multifunctional structures with diverse applications, such as aerospace engineering.

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Trinuclear gold-catalyzed site-selective alkylation of peptides

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Science China Chemistry 2025年第1期68卷 249-256页

作者： Qing-Yun Fang Chengyihan Gu Yinghan Chen Wencheng Yan yong Liang Weipeng Li Chengjian Zhu Jie Han jin Xie State Key Laboratory of Coordination Chemistry Jiangsu Key Laboratory of Advanced Organic Materials Chemistry and Biomedicine Innovation Center (Chem BIC) School of Chemistry and Chemical Engineering Nanjing University Green Catalysis Center College of Chemistry Zhengzhou University State Key Laboratory of Natural Medicines China Pharmaceutical University

Selective modification of peptides has always been a challenging issue. The selective alkylation of peptides can alter the biological activity and physical properties of molecules, and it has gained significant research interest. We herein disclose an intriguing gold-catalyzed alkylation of peptides using bench-stable unactivated alkyl bromides under photoredox catalysis. A wide range of structurally diverse primary, secondary and tertiary alkyl bromides serve as effective coupling partners to precisely connect with the α-C(sp3)–H in glycine residue of peptides. This protocol demonstrates an exceptionally broad scope for alkyl halides and excellent tolerance for a wide range of useful functional groups. A series of relay transformations to construct cyclic peptides, to proceed click reaction and to realize peptide fluorescence labeling further enhance its synthetic practicality. In addition, mechanistic studies and density functional theory(DFT) calculations reveal an inner-sphere and subsequent outersphere single electron transfer(SET) mechanism.

关键词： gold catalysis peptide alkylation C-C coupling radical

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Enhancing m^(6)A modification in the motor cortex facilitates corticospinal tract remodeling after spinal cord injury

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Neural Regeneration Research 2025年第6期20卷 1749-1763页

作者： Tian Qin Yuxin jin Yiming Qin Feifei Yuan Hongbin Lu Jianzhong Hu yong Cao Chengjun Li Department of Spine Surgery and Orthopedics Xiangya HospitalCentral South UniversityChangshaHunan ProvinceChina Key Laboratory of Organ Injury Aging and Regenerative Medicine of Hunan ProvinceChangshaHunan ProvinceChina National Clinical Research Center for Geriatric Disorders Xiangya HospitalCentral South UniversityChangshaHunan ProvinceChina Department of Sports Medicine Xiangya HospitalCentral South UniversityChangshaHunan ProvinceChina

Spinal cord injury typically causes corticospinal tract disruption. Although the disrupted corticospinal tract can self-regenerate to a certain degree, the underlying mechanism of this process is still unclear. N6-methyladenosine(m^(6)A) modifications are the most common form of epigenetic regulation at the RNA level and play an essential role in biological processes. However, whether m^(6)A modifications participate in corticospinal tract regeneration after spinal cord injury remains unknown. We found that expression of methyltransferase 14 protein(METTL14) in the locomotor cortex was high after spinal cord injury and accompanied by elevated m^(6)A levels. Knockdown of Mettl14 in the locomotor cortex was not favorable for corticospinal tract regeneration and neurological recovery after spinal cord injury. Through bioinformatics analysis and methylated RNA immunoprecipitation-quantitative polymerase chain reaction, we found that METTL14 regulated Trib2 expression in an m^(6)A-regulated manner, thereby activating the mitogen-activated protein kinase pathway and promoting corticospinal tract regeneration. Finally, we administered syringin, a stabilizer of METTL14, using molecular docking. Results confirmed that syringin can promote corticospinal tract regeneration and facilitate neurological recovery by stabilizing METTL14. Findings from this study reveal that m^(6)A modification is involved in the regulation of corticospinal tract regeneration after spinal cord injury.

关键词： corticospinal tract remodeling epigenetic regulations locomotor cortex m^(6)A modification methyltransferase 14 protein(METTL14) mitogen-activated protein kinase neural regeneration spinal cord injury syringin TRIB2

基于复合校正控制的高效稳定光伏并网发电装置

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电力电子技术 2017年第8期51卷 100-103页

作者：韦星杨永进金龙东南大学江苏南京210096 上海铁路局南京国铁电气有限责任公司江苏南京210037

设计了一种高效稳定的光伏并网发电装置,可实现光伏电池最大功率点跟踪(MPPT),提高电能转换效率。装置采用软件锁相环(SPLL)闭环控制及复合校正控制,提高系统动态性能及稳态性能,该装置同时设有欠压过流打嗝保护,可长时间安全稳定运行... 详细信息

设计了一种高效稳定的光伏并网发电装置,可实现光伏电池最大功率点跟踪(MPPT),提高电能转换效率。装置采用软件锁相环(SPLL)闭环控制及复合校正控制,提高系统动态性能及稳态性能,该装置同时设有欠压过流打嗝保护,可长时间安全稳定运行。测试结果表明,装置性能指标优良,具有较高的实用价值。

关键词：光伏并网最大功率点跟踪软件锁相环复合校正

微波复合直流等离子体转化天然气制乙炔的研究

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化学学报 2005年第7期63卷 625-630,F008页

作者：徐兴祥杨永进孙家言张劲松中国科学院金属研究所沈阳110016

利用微波复合直流等离子体对天然气转化制乙炔反应进行了研究.考察了氢烷比、气体流量、功率等参数对装置的能量利用率以及天然气转化反应的影响,并考核了微波复合直流等离子体转化天然气制乙炔工艺的稳定性.实验结果表明:微波复合直流... 详细信息

利用微波复合直流等离子体对天然气转化制乙炔反应进行了研究.考察了氢烷比、气体流量、功率等参数对装置的能量利用率以及天然气转化反应的影响,并考核了微波复合直流等离子体转化天然气制乙炔工艺的稳定性.实验结果表明:微波复合直流等离子体装置的能量利用率随等离子体工作气体的流量的增加而提高;由于微波的作用使传统直流柱状等离子体分化为多根丝状等离子体,从而使得电极的烧蚀方式由传统的点烧蚀变为面烧蚀,并大幅度提高等离子体转化天然气工艺的稳定性和电极寿命;甲烷的转化率和乙炔的收率随功率的增加而提高,随CH4/H2比和气体流量的增加而降低,在氢烷比为0.9、总气体流量为760L/min、微波源输出电功率6kW、直流电源输出功率90kW时,甲烷转化率可达84.4%,乙炔选择性为75.6%,乙炔收率为63.8%,乙炔能耗达10.8kWh?kg-1;电极寿命超过200h.

关键词：直流等离子体乙炔复合能量利用率气体流量等离子体装置电源输出功率电极寿命天然气转化转化反应工作气体稳定性转化率等参数大幅度 CH4 电功率微波源工艺传统烧蚀收率甲烷柱状