Valeriy V. Bolotov
,
Vasiliy E. Kan
,
Egor V. Knyazev
,
Peter M. Korusenko
,
Sergey N. Nesov
,
Yuriy A. Sten`kin
,
Viktor A. Sachkov
,
Irina V.Ponomareva
新型炭材料
doi:10.1016/S1872-5805(15)60197-4
采用拉曼光谱仪﹑透射电镜﹑俄歇能谱仪﹑X射线光电子能谱仪等研究在SiO2/Si基底上化学沉积的多壁碳纳米管( MWCNTs)经390℃的空气中热处理120 min前后与HCl溶液化学处理前后的结构变化情况. 拉曼光谱集中测试低频(250-300 cm-1 )带. 结果表明,经热处理和化学处理后,在250-300 cm-1形成的拉曼带在峰位和半宽几乎没变. 由透射电镜可知,小直径碳纳米管的内径值与拉曼光谱测试结果一致. 这些结果表明,低频带产生于小直径碳纳米管的内壁中碳原子的径向呼吸振动.
关键词:
碳纳米管
,
径向振动模式
,
拉曼
,
化学气相沉积
,
显微镜
Acta Chimica Sinica
Passive film formed on 304 stainless steel in 2.5 mol/L H2SO4 solution by using alternating voltage (A. V.) passivation have been investigated by measuring capacitance and photoelectrochemical parameters. The investigation of the effect of measure frequency on the slope of Mott-Schottky curve has been carried out. The photoelectrochemical measurements were consistent with the capacitance measurement. Analysis of the experimental results showed that the passive film formed 304 stainless steel by using A. V. passivation exhibits semiconducting properties. Using the simple model of semiconductor rather than the multi-donor level model can explain satisfactorily the semiconducting behavior of the film formed on 304 stainless steel by using A.V. passivation.
关键词:
A. V. passivation;passive film;semiconducting properties;stainless;steel;model;electrodes
Fatigue & Fracture of Engineering Materials & Structures
Fatigue data for welded joints subjected to an explosion treatment (ET) were obtained using rotary bending fatigue specimens. The fatigue fracture surfaces were observed by SEM and the dislocation morphologies by TEM. Mechanical properties have been quantitively studied by considering elastic and plastic shock wave characteristics. The test results indicate that the fatigue strength of welded joints subjected to ET is apparently improved due to the action of elastic or plastic stress waves while the ductility of the welded joints, i.e., reduction in area, is greatly increased.
关键词:
李红英
,
胡继东
,
康巍
,
李阳华
,
林武
材料热处理学报
采用RBF神经网络对204组X70管线钢生产数据进行训练，建立了管线钢成分与力学性能的预测模型，经检验该模型预报精度高，网络预报值与实际值较吻合。利用此模型预报了C、kin、No、Nb、V、Ti等元素含量对管线钢性能的影响规律，并在此基础上确定了X80管线钢的成分范围。对试制生产的X80管线钢进行组织性能检测，结果表明，X80钢的显微组织主要由针状铁素体和粒状贝氏体组成，晶粒细小，力学性能指标达到X80管线钢应用要求。
关键词:
RBF神经网络
,
成分设计
,
X80管线钢
,
组织性能
李慧玲
,
阮可青
,
王强
,
陈宇
,
钱朔
,
余勇
,
黄利
,
郑重
,
汪成友
,
曹烈兆
低温物理学报
doi:10.3969/j.issn.1000-3258.2003.04.007
研究了不同Pb含量的Bi2-xPbxSr2Co2Oy单晶的输运行为.用A. F. Ho 和A. J. Schofield提出的公式对ρc的温度依赖关系曲线进行了拟合,得到了较好的结果.我们利用小极化子理论解释了ρc的复杂行为.
关键词:
过渡金属氧化物的电导
,
小极化子
蒋宝坤
,
张渲铃
,
李映辉
复合材料学报
doi:10.13801/j.cnki.fhclxb.20140702.004
首先,基于复合材料在湿热环境下的本构关系推导了旋转复合材料梁轴力和弯矩的表达式,分析了温度和湿度对轴力和弯矩的影响,然后,基于d' Alembert原理建立了旋转复合材料梁摆振控制方程,并应用Galer-kin法进行求解,分析了温度和湿度对旋转复合材料梁刚度的影响,最后,通过数值模拟讨论了湿热环境对旋转复合材料梁摆振动力学特性的影响.结果表明:湿热环境对旋转复合材料梁的摆振频率和模态影响显著,摆振频率随湿热环境加剧而降低,热膨胀效应对摆振频率的影响大于材料性能变化对其的影响,湿热环境与旋转的联合作用使模态的节点位置发生明显偏移.
关键词:
湿热环境
,
旋转
,
复合材料梁
,
Galerkin法
,
摆振特性
徐东
,
巫欣欣
,
程晓农
,
张剑平
,
施利毅
材料导报
采用两步烧结制备了Y_2O_3掺杂ZnO压敏瓷,其电位梯度为863～1330V/mm,非线性系数为27.0～49.7,漏电流为0.55～1.13μA.研究结果表明,当Y_2C_3的掺杂量为1.00%(摩尔分数)时,压敏瓷电性能最好,电位梯度为1330V/mm,非线性系数为49.7,漏电流为0.76μA.
关键词:
压敏瓷
,
两步烧结
,
稀土
,
显微组织
,
电性能
Hui WANG
,
Huaxia XIN
,
Jianfeng CAI
,
Fangbing LI
,
Yu JIN
,
Qing FU
色谱
doi:10.3724/SP.J.1123.2016.03006
Astragalus polysaccharides (APS) are important components in Astragalus membranaceus (A. membranaceus). However, for the huge relative molecular mass, strong polarity, and difficulty in chromatographic separation, there's a lack of quality control finely reflecting the composition of APS up to now. To solve the problems, the key lies in degradation of polysaccharides and analysis of the hydrolyzates. A partial acid hydrolysis-hydrophilic interaction liquid chromatography (HILIC) fingerprint for APS and a comprehensive quality evaluation method for A. membranaceus combining with the traditional RPLC fingerprint were developed. Orthogonal experiments were designed to investigate the influencing factors of partial hydrolysis and the conditions were optimized based on HILIC analysis. The hydrolyzates were successfully separated using HILIC-evaporative light scattering detection (ELSD) method and the optimal conditions of hydrolysis were selected as 80℃, 1.5 mol/L trifluoroacetic acid and 4 h, which proved to be stable and repeatable after the validation. This method was applied for the fingerprint analysis of 20 batches of A. membranaceus. Cosine method was used for similarity calculation using the average of samples Nos. 1-10 as reference. Moreover, RPLC fingerprint analysis was processed on other components and the data were compared for comprehensive evaluation. The similarities of ten samples with the reference ranged from 0.258 to 0.949, which were consistent with the chromatograms reflecting the apparent disparity in APS, and could be as a supplement of the RPLC fingerprint. The new method, with the advantages of intuition, convenience, and quantifiable in similarity, could reflect the differences of the composition of polysaccharides after degradation and was successfully applied in profiling of APS, contributing to the quality control together with the RPLC fingerprint.
关键词:
partial acid hydrolysis
,
hydrophilic interaction liquid chromatography (HILIC)
,
Astragalus polysaccharides (APS)
,
fingerprint
,
quality evaluation
任世科
,
骆重阳
腐蚀与防护
通过静态、动态腐蚀试验和现场应用试验,对新研制的LX3032无缝钢管在HCl-H2S-H2O环境中的腐蚀速率进行了测定.结果显示,与其他几种常用钢材相比,LX3032具有良好的耐腐蚀性能,能满足在HCL-H2S-H2O腐蚀环境下冷换设备的安全使用,腐蚀速率低于国标所限定的0.125mm/a.
关键词:
换热器
,
应力腐蚀
,
管束
