材料期刊网

A Fractal Study on Brittle-Ductile Transition for Ti-24Al-11Nb Alloy

Guoliang CHEN , Yandong WANG , Yuanding HUANG , Zuqing SUNand Wangyue YANG(State Key Lab. for Adv. Met , Mater. , University of Science and Technology Beijing , Beijing , Beijing , 100083 , China)(To whom correspondence should be addressed)

材料科学技术（英文）

The mechanical behaviours of Ti-24Al-11Nb alloy in the brittle-ductile transition (BOT) have been investigated by using three-point bending tests. The temperature dependence of the fractal dimensions and fractal characterization of fracture surfaces are presented. The probable mechanism controlling BDT of intermetallic alloys are proposed according to fractal geometry.Additionally. it is found that there is a positive relationship between the fractal dimension and fracture toughness in BDT for Ti-24Al-11Nb alloy

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CLAS+FROST: new generation of photoproduction experiments at Jefferson Lab.

中国物理C

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基于ADV212的远程图像采集系统设计

陶宏江 , 韩双丽 , 张宇 , 郝贤鹏 , 金龙旭

液晶与显示 doi:10.3788/YJYXS20132801.0105

针对彩色高清图像远程网络传输带宽需求过大的问题,提出了基于ADV212图像压缩芯片结合FPGA的压缩、传输解决方案.设计中以彩色高清Bayer格式CMOS作为图像传感器,使用ADV212实现对图像的快速高质量压缩,通过FPGA实现整个系统的控制逻辑,实现对ADV212的配置、驱动以及压缩前图像的分配和压缩后码流数据的打包处理.实验表明该系统可以保证接收图像具有较高的峰值信噪比,能够长期稳定地工作在36 Mbyte/s的图像输入条件下,且该系统具有体积小、使用灵活方便、带宽占用低和压缩率可调等优点.

关键词: ADV212 , JPEG2000 , FPGA , Bayer Pattern , 以太网

Key Problems in Microforming Processes of Microparts

Chunju WANG , Debin SHAN , Bin GUO , Jian ZHOU , Lining SUN

材料科学技术（英文）

From the viewpoint of production engineering, microforming is considered as an effective process to fabricate various microparts. Several key problems in microforming processes were investigated. A new microforming apparatus with a high stiffness piezoelectric actuator as the punch driver was developed to produce microparts. To improve the forming abilities and locate the billets, a floating microdie was designed. The size effects of the billets and die cavities on the microforming abilities were studied with upsetting and coining tests, respectively. And the isothermal microforming process of microgears was performed with the developed microforming apparatus. Several analysis methods were used to evaluate the forming quality of the microparts.

关键词: Microforming , 尺寸效应 , 微塑性成形设备 , 浮动

LaB6功能陶瓷材料的研究现状

郑树起 , 闵光辉 , 于化顺 , 韩建德 , 王维倜 , 张树玉

材料导报

综述了目前国内外LaB6功能陶瓷材料的研究概况及应用,综合了制备LaB6粉末、多晶、单晶的各种工艺.

关键词: LaB6 , 功能陶瓷 , 制备工艺

以DMDMH和MET为配位剂的无氰镀银工艺研究

贾晓凤 , 杜朝军

表面技术 doi:10.3969/j.issn.1001-3660.2010.04.018

研究了以Met和DMDMH为配位剂的无氰镀银工艺,通过探讨镀液组成及工艺条件对镀层外观质量的影响,确定了最佳电镀工艺.测试了镀液的阴极电流效率、分散能力、覆盖能力,以及银镀层的微观形貌和结合强度等.测试结果表明,该无氰镀银工艺基本达到了氰化物镀银工艺的相关指标,有望成为氰化物镀银的替代工艺.

关键词: DMDMH , 蛋氨酸 , 无氰镀银 , 配位剂

The present status and key problems of carbon nanotube based polymer composites

Express Polymer Letters

The state-of-art and key problems of carbon nanotube (CNT) based polymer composites (CNT/polymer composites) including CNT/polymer structural composites and CNT/polymer functional composites are reviewed. Based on the results reported up to now, CNTs can be an effective reinforcement for polymer matrices, and the tensile strength and elastic modulus of CNT/polymer composites can reach as high as 3600 MPa and 80 GPa, respectively. CNT/polymer composites are also promising functional composite materials with improved electrical and thermal conductivity, etc. Due to their multi-functional properties, CNT/polymer composites are expected to be used as low weight structural materials, optical devices, thermal interface materials, electric components, electromagnetic absorption materials, etc. However, the full potential of CNT/polymer composites still remains to be realized. A few key problems, such as how to prepare structure-controllable CNTs with high purity and consistently dependable high performance, how to break up entangled or bundled CNTs and then uniformly disperse and align them within a polymer matrix, how to improve the load transfer from matrix to CNT reinforcement, etc, still exist and need to be solved in order to realize the wide applications of these advanced composites.

关键词: polymer composites;carbon nanotubes;mechanical properties;electrical;properties;thermal properties

Zn(Met)Ac2·H20固态配合物的制备及标准生成焓

任宜霞 , 陈沛 , 陈三平 , 杨旭武 , 高胜利

应用化学 doi:10.3969/j.issn.1000-0518.2004.06.010

在水-丙酮混合溶剂中合成了Zn(Met)Ac2·H2O固态配合物,通过化学分析、元素分析、IR、DSC和TG-DTG对其组成、结构及热稳定性进行了表征.得出其脱水过程和分解过程的焓变分别为15.30 J/g和357.80 J/g.用转动弹热量计测得其恒容燃烧能△cE为(-6 472.11±2.20) kJ/mol,计算得其标准燃烧焓△cH0m和标准生成焓△fH0m分别为(-6 475.21±2.20)kJ/mol和(-429.04±2.59)kJ/mol.

关键词: 水合醋酸锌 , L-α-蛋氨酸配合物 , 制备 , 生成焓

Key problems of cold power spinning of Ti-15-3 alloy

材料科学技术（英文）

The key problems of cold power spinning of Ti-15-3 alloy are studied. Reasonable biller preparation methods are presented to improve crystal structure and avoid crack of billet. Influences of original wall thickness, reduction rate and feed rate on expanding in diameter are analyzed and some methods to prevent expanding in diameter are given.

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Key problems of cold power spinning of Ti-15-3 alloy

Debin SHAN , Yan LU , Ping LI , Yi XU

材料科学技术（英文）

The key problems of cold power spinning of Ti-15-3 alloy are studied. Reasonable biller preparation methods are presented to improve crystal structure and avoid crack of billet. Influences of original wall thickness, reduction rate and feed rate on expanding in diameter are analyzed and some methods to prevent expanding in diameter are given.

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