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面向海工结构阴极防护用纳米水泥基热电复合材料制备及其温差自供能性

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复合材料学报 2024年第5期41卷 2662-2673页

作者：袁士柯罗健林高乙博滕飞张纪刚刘昂张立卿青岛理工大学土木工程学院青岛266520 海洋混凝土教育部工程研究中心青岛266520 华东交通大学土木工程学院南昌330013

经略海洋及双碳背景下,用阴极防护(CP)技术提升海工结构服役寿命具有重要意义,然而需外加电源额外驱动。为此本文先用水热法合成纳米二氧化锰(nMnO_(2)),然后与碳纳米管(CNTs)复掺水泥砂浆体系中,制备纳米水泥基热电复合材料(NTEC);最后... 详细信息

经略海洋及双碳背景下,用阴极防护(CP)技术提升海工结构服役寿命具有重要意义,然而需外加电源额外驱动。为此本文先用水热法合成纳米二氧化锰(nMnO_(2)),然后与碳纳米管(CNTs)复掺水泥砂浆体系中,制备纳米水泥基热电复合材料(NTEC);最后将20个NTEC串联成1套热电发电模块,并结合电化学方法综合评价基于温差发电的NTEC热电模块直接用作海工结构钢筋CP系统电流供给源的可行性。结果表明:复掺有0.2wt%CNTs与5.0wt%nMnO_(2)的NTEC试件的热电系数、热电功率因数可分别达3612μV/℃和301.4μW·m^(-1)·℃^(-2),本征力学强度与耐久抗渗性得到保障;施加基于NTEC温差发电的CP,钢筋的腐蚀电位正移,腐蚀概率显著降低;施加基于NTEC热电模块的CP后能使钢筋腐蚀电流密度降低3个数量级,腐蚀电荷转移得到了抑制,腐蚀速率大为降低,实现海工结构钢筋CP的自供能,同时保障了其用作保护层的强度与耐久性。

关键词：海工结构阴极防护自供能纳米水泥基热电复合材料温差发电性能电化学性能

Charge density wave transition in Na_2Ti_2Sb_2O probed by^(23)Na NMR

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Science China(Physics,Mechanics & Astronomy) 2013年第12期56卷 2399-2403页

作者： FAN GuoZhi ZHANG Xu SHI YouGuo luo jianlin Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of Sciences

Herein we investigated the electronic properties of layered transition-metal oxides NazTi2Sb2O by 23Na nuclear magnetic reso- nance （NMR） measurement. The resistivity, susceptibility and specific heat measurements show a phase transition at approxi- mately 114 K （TA）. No splitting or broadening in the central line of 23Na NMR spectra is observed below and above the transi- tion temperature indicating no internal field being detected. The spin-lattice relaxation rate divided by T （I/T1T） shows a sharp drop at about 110 K which suggests a gap opening behavior. Below the phase transition temperature zone, I/T1T shows Fermi liquid behavior but with much smaller value indicating the loss of large part of electronic density of states （DOS） because of the gap. No signature of the enhancement of spin fluctuations or magnetic order is found with the decreasing temperature. These results suggest a commensurate charge-density-wave （CDW） phase transition occurring.

关键词： layered transition-metal oxides charge-density-waves NMR

Anomalous Specific Heat Behavior of Nanocrystalline Fe at Low Temperatures

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Chinese Physics Letters 1995年第9期12卷 549-552页

作者： BAI Haiyang luo jianlin JIN Duo SUN Jirong Cryogenic Laboratory Chinese Academy of SciencesBeijing 100080 Institute of Physics Chinese Academy of SciencesBeijing 100080

The specific heat of nanocrystalline iron with grain size of 40nm has been measured in the low temperature range from 1.8 to *** anomalous specific heat behavior of nanocrystalline iron is compared to that of the standard bulk *** is found that the electronic specific heat coefficientγobtained at low temperatures decreases by about 50%.A T^(2) term in the heat capacity associated with surface modes has been clearly observed.A large enhancement of the specific heat at temperatures above 16K may be interpreted as the Einstein oscillator contributions.

关键词： grain coefficient heat

31p NMR study of magnetic phase transitions of MnP single crystal under 2 GPa pressure

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Science China(Physics,Mechanics & Astronomy) 2016年第5期59卷 7-10页

作者： GuoZhi Fan Bo Zhao Wei Wu Ping Zheng jianlin luo Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100190 China Collaborative Innovation Center of Quantum Matter Beijing 100190 China

Superconductivity on the border of the long-range magnetic order has been discovered in Mn P under high pressures. In order to investigate the nature of the magnetic properties adjacent to the superconducting state, we performed zero-field 31 P NMR for Mn P single crystal under ambient and hydrostatic pressure of 2 GPa, respectively. Radio frequency power level was used to determine whether NMR signal originates from a helical state or not. When 2 GPa pressure was applied, the signal from helical state exists even above 160 K, while that from the ferromagnetic phase was not observed. Our NMR results indicate that the magnetic phase which is adjacent to the superconducting state is in a helical magnetic structure.

关键词： superconducting materials magnetic phase transitions nuclear magnetic resonance MnP

Low temperature properties of pnictide CrAs single crystal

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Science China(Physics,Mechanics & Astronomy) 2010年第7期53卷 1207-1211页

作者： WU Wei ZHANG XiaoDong YIN ZhiHua ZHENG Ping WANG NanLin luo jianlin Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China

High quality single crystal CrAs was grown by Sn flux *** results of magnetic susceptibility and electrical resistivity are reported in a temperature range of 2 to 800 *** low temperatures,a T2 dependence of resistivity is observed showing a Fermi-liquid *** Kadowaki-Woods ratio is found to be 1×10-5 μΩ cm mol2 K2 mJ-2,which fits well to the universal value for many correlated electron *** about 270 K,a clear magnetic transition is observed with sharp changes of resistivity and *** 270 K,a linear-temperature dependence of the magnetic susceptibility is observed up to 700 K,which resembles the T-dependent magnetic susceptibility of parents of iron-pnictides superconductors.

关键词： CrAs Kadowaki-Woods ratio magnetic phase transition linear T-dependent magnetic susceptibility

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3D打印混凝土增强技术研究进展

硅酸盐通报 2024年第5期43卷 1557-1568页

作者：毛宇飞郭增辉陈晖张杰罗健林刘超商怀帅中国水利水电第五工程局有限公司成都610066 青岛理工大学土木工程学院海洋混凝土技术教育部工程研究中心青岛266520 东南大学材料科学与工程学院南京211189

3D打印技术颠覆了传统材料的成型工艺,广泛应用于航空航天、汽车制造、生物医疗、建筑工程等领域。混凝土原材料来源广且成本低,可塑性良好,在基础设施领域应用广泛。在当今信息化和自动化大背景下,3D打印技术与混凝土结合生产的3D打印... 详细信息

3D打印技术颠覆了传统材料的成型工艺,广泛应用于航空航天、汽车制造、生物医疗、建筑工程等领域。混凝土原材料来源广且成本低,可塑性良好,在基础设施领域应用广泛。在当今信息化和自动化大背景下,3D打印技术与混凝土结合生产的3D打印混凝土(3DPC)不仅能有效节省原料、环保施工,而且能够更加灵活地建造各类智能自动化程度高的装配结构。然而,目前3DPC仍存在抗拉强度低、抗震性差、配筋难、层间黏结强度低等诸多局限性,需要发展各种增强技术来提高性能,所以本文利用钢筋增强、纤维增强和其他方法增强方法分别论述各类补强材料对3DPC性能的影响,并且指出可能存在的问题和未来发展趋势。

关键词： 3D打印混凝土增强技术打印性能力学性能纤维

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Superconductivity in chromium nitrides Pr3Cr10-xN11 with strong electron correlations

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National Science Review 2020年第1期7卷 21-26页

作者： Wei Wu Kai Liu Yanjie Li Zhenhai Yu Desheng Wu Yuting Shao Shihang Na Gang Li Ruizhen Huang Tao Xiang jianlin luo Beijing National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of Sciences School of Physical Sciences University of Chinese Academy of Sciences Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices Renmin University of China School of Physical Science and Technology Shanghai Tech University Songshan Lake Materials Laboratory Kavli Institute for Theoretical Sciences

Exploration of superconductivity in Cr-based compounds has attracted considerable interest because only a few Cr-based superconductors(CrAs, A2Cr3As3and ACr3As3（A = K, Rb, Cs, Na）) have been discovered so far and they show an unconventional pairing mechanism. We report the discovery of bulk superconductivity at 5.25 K in chromium nitride in Pr3Cr10-xN11with a cubic lattice structure. A relatively large upper critical field of Hc2（0）～12.6 T is determined, which is larger than the estimated Pauli-paramagnetic pair-breaking magnetic field. The material has a large electronic specific-heat coefficient of 170 mJ K-2mol-1—about 10 times larger than that estimated by the electronic structure calculation,which suggests that correlations between 3d electrons are very strong in Pr3Cr10-xN11, and thus quantum fluctuations might be involved. Electronic structure calculations show that the density of states at the Fermi energy are contributed predominantly by Cr 3d electrons, implying that the superconductivity results mainly from the condensation of Cr 3d electrons. Pr3Cr10-xN11represents a rare example of possible unconventional superconductivity emerging in a 3D system with strong electron correlations. Nevertheless,clarification of the specific pairing symmetry needs more investigation.

关键词： Cr-based superconductors nitrides strong electron correlations unconventional superconductivity

S-Wave Superconductivity in Kagome Metal CsV_(3)Sb_(5) Revealed by ^(121/123)Sb NQR and ^(51)V NMR Measurements

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Chinese Physics Letters 2021年第7期38卷 140-144页

作者： Chao Mu Qiangwei Yin Zhijun Tu Chunsheng Gong Hechang Lei Zheng Li jianlin luo Beijing National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100190China Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials&Micro-nano Devices Renmin University of ChinaBeijing 100872China Songshan Lake Materials Laboratory Dongguan 523808China

We report ^(121/123)Sb nuclear quadrupole resonance(NQR)and ^(51)V nuclear magnetic resonance(NMR)measurements on kagome metal CsV_(3)Sb_(5) with T_(c)=2.5 *** ^(51)V NMR spectra and ^(121/123)Sb NQR spectra split after a charge density wave(CDW)transition,which demonstrates a commensurate CDW *** coexistence of the high temperature phase and the CDW phase between 91 K and 94 K manifests that it is a first-order phase *** low temperature,electric-field-gradient fluctuations diminish and magnetic fluctuations become *** emerges in the charge order *** shift decreases and 1/T_(1)T shows a Hebel–Slichter coherence peak just below T_(c),indicating that CsV_(3)Sb_(5) is an s-wave superconductor.

关键词： transition state NMR

S-,P-stabilized bromoallenes for modular allenylborylation of alkenes

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Science China Chemistry 2024年第1期67卷 360-367页

作者： Jixin Wang Donghao luo Ying Hu Zhili Duan jianlin Yao Konstantin Karaghiosoff Jie Li Key Laboratory of Organic Synthesis of Jiangsu Province Suzhou Key Laboratory of Pathogen Bioscience and Anti-infective MedicineCollege of ChemistryChemical Engineering and Materials ScienceSoochow UniversitySuzhou 215123China Department Chemie Ludwig-Maximilians-Universitat MunchenButenandtstr.5-13Haus F81377 MunichGermany State Key Laboratory and Institute of Elemento-Organic Chemistry Haihe Laboratory of Sustainable Chemical TransformationsCollege of ChemistryNankai UniversityTianjin 300071China

Simultaneously forming a carbon-carbon and a carbon-heteroatom bond in a single step through transition metal-catalyzed alkene difunctionalization strategy has emerged as a powerful tool for synthetic organic *** to the uncontrollable reactivity,direct cross-coupling with bromoallenes as the building blocks for the selective allenation and borylation remains *** herein report a new type of S-and P-stabilized bromoallenes for palladium-catalyzed modular allenation and borylation of alkenes to the divergent synthesis of multiply functionalized allenes in a highly regio-and diastereoselective *** reaction features broad substrate scope and wide functional group compatibility,thus providing a straightforward method to install allenyl and boryl groups across *** experiments highlight the crucial importance of S-,P-stabilization for the oxidative insertion of Pd-species into the allenyl-Br *** facile syntheses of bioactive allenic steroids and exocyclic allenes demonstrate the synthetic utility of this protocol.

关键词： alkene difunctionalization olefins bromoallenes allenylborylation palladium