L.P. Karjalainen
,
M.C. Somani
,
S.F. Medina
金属学报(英文版)
The analysis of numerous experimental equations published in the literature reveals a
wide scatter in the predictions for the static recrystallization kinetics of steels. The
powers of the deformation variables, strain and strain rate, similarly as the power
of the grain size vary in these equations. These differences are highlighted and the
typical values are compared between torsion and compression tests. Potential errors
in physical simulation testing are discussed.
关键词:
physical simulation
,
null
,
null
,
null
,
null
马保国
,
许婵娟
,
钟开红
,
蹇守卫
,
李相国
材料科学与工程学报
doi:10.3969/j.issn.1673-2812.2005.04.006
本文系统地研究了F、S、P元素对水泥熟料矿物形成过程和组成的影响及其叠加矿化效应,并通过化学分析和XRD分析探讨了其作用机理.研究结果表明:F、S、P元素在水泥烧成中均可降低液相出现和C3S形成温度,改善易烧性,但F、S叠加矿化效果最好,而且可以改善熟料的矿物组成及性能,避免了单掺F造成的熟料活性降低等问题.
关键词:
矿化效应
,
氟石膏
,
磷石膏
,
易烧性
郭艳青
,
任中洲
原子核物理评论
在单粒子势模型的框架下,计算了O同位素和F同位素的基态和某些低激发态的能级值、均方根半径值及密度分布.通过在伍兹-萨克逊势中引入同位旋依赖项,研究了同位旋效应对F同位素s-d能级间隙的影响.理论计算得到的均方根半径值和自旋宇称值与实验结果一致.尤其是,理论计算能够实现16F,15F和14F中2s1/2与1d5/2质子能级间的反转,且F同位素中s-d质子能级间隙及其整体变化趋势与已知实验结果符合较好.此外,理论结果表明12F的(1/2)+第一激发态为单质子晕态.
关键词:
同位旋效应
,
能级反转
,
质子晕
贺成红
,
张佐光
,
李玉彬
,
孙志杰
材料工程
doi:10.3969/j.issn.1001-4381.2008.06.008
考察了单向、正交和准各向同性S-2 /F46复合材料低速冲击后的剩余弯曲强度和模量,结合冲击损伤形貌比较了其冲击损伤模式及演化过程.单向复合材料的冲击损伤呈突变式发展,而正交和准各向同性复合材料则呈多阶段渐进式发展,弯曲性能衰减也呈现相应模式.只有当试样的结构完整性损失较大时弯曲性能才明显下降,其衰减的临界冲击能以单向复合材料最大,正交复合材料最小.此外,角铺层复合材料弯曲模量比强度衰减更严重.
关键词:
复合材料
,
铺层结构
,
冲击
,
损伤
,
弯曲性能
侯长军
,
黄清菁
,
霍丹群
,
张宿义
,
沈才洪
,
张良
功能材料
Receptor-Spacer-Fluorophore(R-S-F)结构型荧光分子传感器是由可选择性结合客体的主体基团与传递信号的荧光团通过桥联基团连接而成的一类分子传感器,结合了超分子在分子识别中良好的选择性和荧光信号的高灵敏度两个优点,成为一类可用于检测金属离子并具巨大发展潜力的新型光学敏感材料.以超分子主体化合物冠醚、杯芳烃结构为分类依据,从主体基团选择性能角度综述了近5年已成功合成并用于金属离子检测的R-S-F型荧光分子传感器及其研究的最新进展.
关键词:
荧光分子传感器
,
分子识别
,
冠醚
,
杯芳烃
,
卟啉
Journal of Magnetism and Magnetic Materials
The first principles within the full potential linearized augmented plane wave (FP-LAPW) method with the generalized gradient approximation (GGA) approach were applied to study the new mixed valence compound Ba(2)F(2)Fe(1.5)S(3). The density of states, the electronic band structure and the spin magnetic moment are calculated. The calculations reveal that the compound has an antiferromagnetic interaction between the Fe(III) and Fe(II) ions arising from the bridging S atoms, which validate the experimental assumptions that there is a low-dimensional antiferromagnetic interaction in Ba(2)F(2)Fe(1.5)S(3). The spin magnetic moment mainly comes from the Fe(III) and Fe(II) ions with smaller contribution from S anion. By analysis of the band structure, we find that the compound has half-metallic property. (C) 2008 Elsevier B.V. All rights reserved.
关键词:
DFT;Antiferromagnetic;Electronic structure;Superexchange interaction;Mixed valence iron compound;fe-57 mossbauer spectrum;transition point;magnetite;ilvaite;systems
王建业
,
赵志换
,
范济民
,
朱力校
功能材料
doi:10.3969/j.issn.1001-9731.2013.10.030
以尿素、硫脲和氟化铵为掺杂物,采用一步水热法制备可见光响应的不同非金属共掺杂TiO2纳米管(TiO2NT).通过SEM、TEM、XRD、BET、FTIR、UV-Vis DRS等对样品进行了表征,考察其吸附性能及在模拟太阳光下对甲基橙的降解活性.结果表明,在碱性条件下一步水热法制备的不同非金属共掺杂TiO2NT具有较大的比表面积(193.93 m2/g)和较小的带隙能(2.76eV),非金属共掺杂明显提高了可见光利用率.在可见光辐照下,硫脲掺杂TiO2纳米管(N,S-TiO2 NT)复合材料的光催化性能最好,反应100min后甲基橙降解率可达87.4％,降解过程符合一级动力学方程.
关键词:
一步水热合成法
,
TiO2纳米管
,
非金属共掺杂
,
甲基橙
,
光催化降解
YANG Ying
,
YAN Qing-zhi
,
GE Chang-chun
钢铁研究学报(英文版)
Modified CNS-Ⅱ F/M steel was designed for in-core components of supercritical water cooled reactor. Study on the hot deformation behavior of modified CNS-Ⅱ F/M steel is of great importance for processing parameter planning and microstructure controlling during hot deformation. The hot deformation behavior of modified CNS-Ⅱ F/M steel was investigated through isothermal hot compression test at temperature ranging from 1223 to 1373 K and strain rate 001 to 10 s-1. The true stress-true strain data gained from compression tests were used to built constitutive equation of modified CNS-Ⅱ F/M steel. The influence of strain on the accuracy of constitutive analysis was incorporated, assuming strain has a influence on material constants. A 5th order polynominal equation with very good accuracy was used to represent the influence of strain on material constant. The flow stresses calculated from the constitutive equation were compared with test values in the whole experiment range and the absolute average error for the constitutive equation in predicting flow stress is 4728%. At last, the recrystallization behavior of modified CNS-Ⅱ F/M steel was investigated. The relationship of critical strain and peak strain with Zener-Hollomon parameter were given by an experimental equation.
关键词:
F/M steel
,
constitutive equation
,
dynamic recrystallization
YANG Ying
,
YAN Qing-zhi
,
MA Rong
,
GE Chang-chun
钢铁研究学报(英文版)
Ferritic/martensitic (F/M) steels have been recommended as one of the candidate materials for supercritical water cooled reactor (SCWR) in-core components use for its high thermal conductivity, low thermal expansion coefficient and inherently good dimensional stability under irradiation condition in comparison to austenitic steel. CNS-Ⅱ F/M steel which has good mechanical properties was one of the 9-12Cr F/M steels designed for SCWR in the previous work. In this study a modified CNS-Ⅱ F/M steel was used and it′s ultimate tensile strength was 925 MPa at room temperature and 483 MPa at 600 ℃ after optimizing heat treatment parameter. The ductile to brittle transition temperature of modified CNS-Ⅱ F/M steel is -55 ℃. Those are at the same level or even higher than that of CNS-Ⅱ and some commercial F/M steels nominated for SCWR in-core component use. The transmission electron microscope (TEM) results showed that the mechanical properties of the tempered martensite was closely related to the decomposition stage of the martensite.
关键词:
supercritical water reactor
,
ferritic/martensitic steel
,
cladding material
