共查询到20条相似文献,搜索用时 13 毫秒
1.
Jijian Xu Dong Wang Heliang Yao Kejun Bu Jie Pan Jianqiao He Fangfang Xu Zhanglian Hong Xiaobo Chen Fuqiang Huang 《Advanced materials (Deerfield Beach, Fla.)》2018,30(10)
Nano TiO2 is investigated intensely due to extraordinary photoelectric performances in photocatalysis, new‐type solar cells, etc., but only very few synthesis and physical properties have been reported on nanostructured TiO or other low valent titanium‐containing oxides. Here, a core–shell nanoparticle made of TiO core covered with a ≈5 nm shell of amorphous TiO1+x is newly constructed via a controllable reduction method to synthesize nano TiO core and subsequent soft oxidation to form the shell (TiO1+x). The physical properties measurements of electrical transport and magnetism indicate these TiO@TiO1+x nanocrystals are a type‐?? superconductor of a recorded Tconset = 11 K in the binary Ti–O system. This unusual superconductivity could be attributed to the interfacial effect due to the nearly linear gradient of O/Ti ratio across the outer amorphous layer. This novel synthetic method and enhanced superconductivity could open up possibilities in interface superconductivity of nanostructured composites with well‐controlled interfaces. 相似文献
2.
采用高温熔盐灼烧法研究T2钛合金高温腐蚀动力学及腐蚀行为.分别在500,600,700,800℃的Na2SO4或Na2SO4(80%) NaCl(20%)环境中发现T2钛合金腐蚀增重符合直线规律,直线通式为y=KLt.随着温度的增加,直线的速率常数KL增大.混合盐Na2SO4(80%) NaCl(20%)比纯Na2SO4的加速腐蚀作用更加明显.在Na2SO4或Na2SO4(80%) NaCl(20%)中,T2钛合金随温度升高,氧化膜的完整性降低.合金中Al,Zr等元素在腐蚀中向合金表面扩散,而盐中的S,Cl等元素则向合金内部扩散. 相似文献
3.
4.
针对Ti-Al-Zr-Mo-Nb-Sn-Si铸造高温钛合金,研究了其在600℃、750℃下的蠕变性能与组织变化。结果显示,该铸造钛合金在750℃/180 MPa/0.5 h和600℃/400 MPa/0.5 h条件下的蠕变残余伸长率分别<3%和<0.4%,持久断裂时间分别为>2 h和14 h,具有良好的蠕变性能;高温蠕变断口存在细小颗粒;高温蠕变后塑性变形区的组织变化较小,呈魏氏组织,而集中变形区存在部分晶界消失、α片层宽化现象;高温蠕变后位错明显增多,与析出相相互纠缠。 相似文献
5.
6.
钛合金焊接冶金研究进展 总被引:2,自引:0,他引:2
韩忠 《材料科学与工程学报》2000,18(4):107-110
概括介绍了钛合金焊接的主要特点 ,综述了钛合金焊接冶金方面的研究进展 ,并阐述了该领域的研究前景。 相似文献
7.
8.
9.
目的研究表面纳米化Ti合金与Ti Al合金异质扩散连接的界面反应、力学性能和工艺条件。方法利用高能喷丸技术对钛合金的表面进行纳米化处理,然后在高温压力真空炉内进行扩散连接实验。结果 Ti合金/Ti Al扩散连接的结合强度与中间层厚度密切相关,当中间层厚度为1.7~2.0μm时,剪切强度最大。结论表面纳米化可以促进原子扩散、增加接头厚度、缩短扩散连接所需的时间。对于扩散界面存在缝隙接头,在无压热处理条下表面纳米化样品可以快速提高焊合率,改善连接质量。 相似文献
10.
Feng Ke Haini Dong Yabin Chen Jianbo Zhang Cailong Liu Junkai Zhang Yuan Gan Yonghao Han Zhiqiang Chen Chunxiao Gao Jinsheng Wen Wenge Yang Xiao‐Jia Chen Viktor V. Struzhkin Ho‐Kwang Mao Bin Chen 《Advanced materials (Deerfield Beach, Fla.)》2017,29(34)
An unexpected superconductivity enhancement is reported in decompressed In2Se3. The onset of superconductivity in In2Se3 occurs at 41.3 GPa with a critical temperature (Tc) of 3.7 K, peaking at 47.1 GPa. The striking observation shows that this layered chalcogenide remains superconducting in decompression down to 10.7 GPa. More surprisingly, the highest Tc that occurs at lower decompression pressures is 8.2 K, a twofold increase in the same crystal structure as in compression. It is found that the evolution of Tc is driven by the pressure‐induced R‐3m to I‐43d structural transition and significant softening of phonons and gentle variation of carrier concentration combined in the pressure quench. The novel decompression‐induced superconductivity enhancement implies that it is possible to maintain pressure‐induced superconductivity at lower or even ambient pressures with better superconducting performance. 相似文献
11.
We have considered the role of charge-density-pseudogap for phonon-mediated super-conductivity on two-dimensional lattice. The propagators that enter generalized Eliashberg equations have been renormalized to account for quasi-particle energies related to the formation of the pseudogap, which has been assumed to be of d-wave symmetry. We have evaluated the superconducting transition temperature Tc as a function of doping. It occurs that Tc for d-wave symmetry well reflects experimental behavior. Our results for the isotope shift exponent show that at low doping, the presence of the pseudogap may contribute to > 1/2 as well as to > 1/2 values. 相似文献
12.
目的获得高强TA18钛管数控弯曲过程的织构演变规律。方法基于高强TA18钛管数控弯曲三维弹塑性显式有限元模型以及耦合粘塑性自洽晶体塑性模型(VPSC),获得钛管数控弯曲过程中的织构演变规律,通过单向拉伸、压缩和数控弯曲实验与EBSD分析验证了织构演变预测的可靠性。结果高强TA18钛管数控弯曲过程中,弯曲角度为0°~90°时,弯曲后管材内外侧均形成径向织构与轴向织构。结论高强TA18钛管的初始织构为近径向织构,在数控弯曲过程中,随弯曲角度增大,管材内侧轴向织构逐渐增多,径向织构先减小后增大;管材外侧的周向织构与轴向织构都逐渐增加;实验对比分析表明,预测的织构变化趋势和实验结果基本一致。 相似文献
13.
目的研究获得基于多指标的高强TA18钛管整体多弯管件成形精度控制的方法。方法在获得高强TA18钛管数控弯曲非线性回弹和伸长规律的基础上,研究回弹角、回弹半径的补偿方法和伸长控制方法,其次将获得的成形精度控制方法进行多弯模拟应用验证。结果对于回弹角和回弹半径,采用先补偿回弹半径再补偿回弹角的两水平顺序控制方法;对于弯曲伸长,采用预先减少管材下料尺寸和改变弯头位置来控制回弹后直线段长度的控制方法。结论应用上述控制方法,将多弯模拟结果与预成形管件几何尺寸进行对比,获得成形角度、半径和直线段长度的最大相对误差分别为1.00%,5.51%和5.04%。上述误差满足多弯管件装配精度要求,证明所提出的成形精度控制方法是可靠的。 相似文献
14.
15.
16.
17.
Mian Chen Zhou Long Ruihua Dong Le Wang Jiangjiang Zhang Sixiang Li Xiaohui Zhao Xiandeng Hou Huawu Shao Xingyu Jiang 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(7)
This study uses metal–organic frameworks (MOFs) alone without any added antibacterial ingredients as the nonantibiotic agent for photodynamic therapy (PDT) of chronic wounds infected by multidrug‐resistant (MDR) bacteria. Nanoparticles (NPs) of MOFs (PCN‐224) are incorporated with titanium through a facile cation exchange strategy. The obtained bimetallic PCN‐224(Zr/Ti) shows greatly enhanced photocatalytic performance for the generation of reactive oxygen species under visible light, which is responsible for the effective antibacterial activities. The PCN‐224(Zr/Ti) NPs are loaded onto lactic‐co‐glycolic acid nanofibers to prepare a wound dressing, which shows high biocompatibility and minimal cytotoxicity. The wound dressing is efficient for PDT‐based in vivo healing of the chronic wound infected by MDR bacteria. Most importantly, this work does not involve any additional antibacterial agents, which is facile, low cost, and in particular, greatly explores the potential of MOFs as a powerful nonantibiotic agent in PDT. 相似文献
18.
Experimental Study on the Effect of Cooling Rate on the Secondary Phase in As‐Cast Mg–Gd–Y–Zr Alloy
下载免费PDF全文
![点击此处可从《Advanced Engineering Materials》网站下载免费的PDF全文](/ch/ext_images/free.gif)
19.
20.