材料期刊网

Modeling of Micromanipulation Robot in Virtual Environment

F.S. Tan , L.N. Sun , W.B. Rong , J. Zhu

金属学报(英文版)

Micromanipulation has been recognized to be very difficult due to the inefficiency of traditional micromanipulation methods. The paper present a general framework for micromanipulation robot based on virtual reality technology. The significance of introducing virtual reality into micromanipulation is analyzed, and the current research in this field is reviewed. Based on this, we propose a micromanipulation system that integrates virtual environment with vision feedback and force feedback. The system realizes vision close-loop control and force close-loop control to enhance the performance of micromanipulation device. A graphics modelling method is proposed for a microassembly task. Hardware and software implementation is described and discussion about the research is presented.

关键词: micromanipulation , null , null

F、S、P元素及其叠加矿化效应研究

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

Microstructural study on multilayer FeTaN/TaN (5) films

Materials Letters

The microstructure of [FeTaN/TaN](5) multilayer films has been investigated by transmission electron microscopy (TEM) and high-resolution electron microscopy (HREM) in cross section and plan view. Each layer shows a small surface roughening less than 1 nm. The FeTaN layers are composed of b.c.c. Fe with Ta incorporated substitutionally and N interstitially, denoted as Fe(Ta,N); while the TaN layers mainly consist of f.c.c. TaN phase. A [110] texture of Fe(Ta,N) has been formed in the FeTaN layers. The columnar grain structure is a typical feature in FeTaN layers. (C) 2003 Elsevier Science B.V. All rights reserved.

关键词: microstructure;thin films;magnetic materials;transmission electron;microscopy (TEM);sputtering;fetan thin-films;magnetic-properties;recording-heads;tantalum;nitride;temperature

同位旋效应对F同位素s-d能级间隙的影响

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

S-2/F46复合材料低速冲击损伤及剩余弯曲性能

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

立方 TaN纳米粉的制备

类伟巍 , 沈龙海 , 刘丹 , 李雪飞 , 彭刚 , 崔启良 , 邹广田

无机材料学报 doi:10.3724/SP.J.1077.2007.00400

采用直流电弧法使金属钽和氮气直接反应制备出了TaN纳米粉．利用XRD、XPS、TEM等测试方法对所制备的TaN纳米粉进行了表征．结果表明: 所制备的纳米粉为单一的立方相TaN, 纳米颗粒的平均粒度为5~10nm．实验中还发现氮气的气压对制备纯立方相TaN具有关键性作用, 并讨论了立方相TaN的形成机理．

关键词: 立方相TaN , nanocrystallites , dc arc discharge method

立方TaN纳米粉的制备

类伟巍 , 沈龙海 , 刘丹 , 李雪飞 , 彭刚 , 崔启良 , 邹广田

无机材料学报 doi:10.3321/j.issn:1000-324X.2007.03.004

采用直流电弧法使金属钽和氮气直接反应制备出了TaN纳米粉.利用XRD、XPS、TEM等测试方法对所制备的TaN纳米粉进行了表征.结果表明:所制备的纳米粉为单一的立方相TaN,纳米颗粒的平均粒度为5～10nm.实验中还发现氮气的气压对制备纯立方相TaN具有关键性作用,并讨论了立方相TaN的形成机理.

关键词: 立方相TaN , 纳米粉 , 直流电弧法

检测金属离子的R-S-F结构型荧光分子传感器研究进展

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

First-principles electronic-structure calculation on the spin distribution and the half-metallic properties of the mixed valence iron compound Ba(2)F(2)Fe(1.5)S(3)

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

Influence of Ar/N2 Flow Rate on Structure and Property for TaN/NbN Multilayered Coatings

Xuehua ZHANG , Yuanbin KANG , Sipeng LIU , Qiang LI , Ying YANG

材料科学技术（英文）

TaN/NbN multilayered coatings with nanoscale bilayer periods were synthesized at different Ar/N2 flow rate by r.f. magnetron sputtering. XRD and nano indenter were employed to investigate the influence of Ar/N2 flow rate on microstructure and mechanical properties of the coatings. The low-angle XRD pattern indicated a well-defined composition modulation and layer structure of the multilayered coating. All multilayered coatings almost revealed higher hardness than the rule-of-mixtures value of monolithic TaN and NbN coatings. At FAr:FN2 =10, the multilayered coating possessed excellent hardness, elastic modulus, internal stress, and fracture resistance, compared with ones synthesized at other Ar/N2 flow rates. The layered structure with strong mixture of TaN (110), (111), (200) and Nb2N (101) textures should be related to the enhanced mechanical properties.

关键词: RF magnetron sputtering , TaN/NbN多层膜 , 纳米尺度