材料期刊网

E®ects of Ag Seed on Synthesis of FeCo Nano-Particles Prepared via the Polyol Method

Uk-Rae Cho Kai Wang Geun-Woo Kim Bon-Heun Koo

材料科学技术（英文）

Nano-particles have several interesting properties which are not shown in bulk materials because of their high ratio of surface area to volume. FeCo alloy nano-particles with soft magnetic properties are demanded for various applications such as optics, eletronics and magnetics. Through the polyol method, highly purified particles with mono-dispersibility in various sizes can be produced and used as high-tech functional materials. In this study, the magnetic characteristics of FeCo alloy with Ag seed added in the production process of mono-dispersed nano-particles through the polyol method were investigated.

关键词: Polyol method , FeCo , Ag , Magnetics

KAI-2093型面阵CCD多模式驱动时序设计

陶明慧 , 张星祥 , 张宇 , 任建岳 , 李新娥

液晶与显示 doi:10.3788/YJYXS20112601.0105

针对某航空相机的设计要求,提出了一种可行的多模式驱动时序设计方法.采用柯达公司的KAI-2093行间转移型面阵CCD传感器.结合它的结构特点和双通道数据传输的思想分析了传感器驱动时序关系,提出了3种驱动模式:binning、no-binning和TDI模式.以Ahera公司的FPGA芯片EP1C6Q240作为时序发生器并实现数据的缓存和拼接,从而实现了时序发生器与数据处理器的一体化设计.在QUARTUSII7.0开发环境下采用VHDL语言编程,通过Modelsim AE6.1b实现数据缓存器的仿真.实测结果表明,所设计的驱动时序满足KAI-2093的时序要求,binning模式下帧频可达60帧/s,120帧/s等,满足高速跟踪要求;no-binning模式下全帧输出帧频可达30帧/s;TDI模式下能保证CCD长时间工作而不影响成像质量,该没计方法提高了系统的集成度和抗干扰能力.

关键词: 航空相机 , binning模式 , TDI模式 , 数据缓存 , 数据拼接 , FPGA

Two-step magnetization in a spin-chain system on the triangular lattice: Wang-Landau simulation

Physical Review B

The Wang-Landau algorithm is used to study the thermodynamic and magnetic properties of triangular spin-chain system based on two-dimensional Ising model in order to understand the magnetic-order dynamics in Ca(3)Co(2)O(6) compound. The calculated results demonstrate that the equilibrium state of the rigid spins produces the two-step magnetization curve at low temperature even when the random-exchange term is considered. This work indicates that the four-step magnetization behavior observed experimentally must be due to the nonequilibrium magnetization.

关键词: calcium compounds;exchange interactions (electron);Ising model;magnetisation;thermodynamics;one-dimensional ca3co2o6;density-of-states;compound ca3co2o6;phase-diagram;proteins;crystal

PBLG-PEG-PBLG嵌段共聚物的合成及其CHO细胞毒性

王琴梅 , 滕伟 , 张静夏 , 潘仕荣

应用化学 doi:10.3969/j.issn.1000-0518.2006.09.006

以端氨基聚乙二醇(AT-PEG)引发谷氨酸苄酯N-羧酸酐(BLG-NCA)开环聚合得到聚谷氨酸苄酯-聚乙二醇-聚谷氨酸苄酯嵌段共聚物(PBLG-PEG-PBLG,缩写为GEG),用GPC、IR、1H NMR测试技术表征了共聚物的结构;在GEG膜表面培养中国仓鼠肺泡成纤维细胞(CHO),用光学显微镜和扫描电子显微镜观察聚合物表面细胞粘附、生长、繁殖的情况. 结果表明,AT-PEG能引发BLG-NCA开环聚合形成嵌段共聚物,所有的聚合物都没有细胞毒性,细胞在某些共聚物上的生长和繁殖比均聚物好.当PEG的分子量为2 000,且PEG单体单元的摩尔含量占共聚物中总单体含量的59%时,细胞不能贴附在共聚物表面. 通过控制共聚物中PEG嵌段的含量可调节细胞在聚合物表面上的粘附和生长.

关键词: 聚谷氨酸苄酯 , 聚乙二醇 , 嵌段共聚物 , 细胞毒性

Ion sputter erosion in metallic glass-A response to "Comment on: Homogeneity of Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass" by L-Y. Chen, Y-W. Zeng, Q-P. Cao, B-J. Park, Y-M. Chen, K. Hono, U. Vainio, Z-L. Zhang, U. Kaiser, X-D. Wang, and J-Z Jiang J. Mater. Res. 24, 3116 (2009)

Journal of Materials Research

The morphology of the dark and bright regions observed by transmission electron microscopy for the Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass strongly depends on the ion beam parameters used for ion milling. This indicates that the ion beam could introduce surface fluctuation to metallic glasses during ion milling.

关键词: room-temperature

壳聚糖-聚乙烯亚胺基因载体的制备

段丽红 , 王浩 , 郑琼娟 , 全大萍

高分子材料科学与工程

利用醛化壳聚糖（CS-CHO）的醛基与聚乙烯亚胺（PEI）的氨基间的反应形成高分子缀合物来制备低毒,又有一定效果的基因载体。合成了醛化度为29.6%的CS-CHO,并通过傅立叶红外光谱及核磁共振的方法对其结构进行了表征。采用分子量为600g/mol的PEI与该CS-CHO进行反应,研究了CS-CHO与PEI的投料比、投料顺序对接枝度的影响,实验结果表明,投料比对接枝度的影响很大,在PEI与CS-CHO的物质的量比小于2∶1时,接枝度随着PEI的量的增加而增加,最大为41.87%,但之后继续增加PEI的量而接枝度由41.87%减小到26.98%。投料顺序对接枝度的影响则相对较小,物质的量比为2∶1的CS-CHO与PEI直接混合获得的接枝度最大,为29.21%。

关键词: 壳聚糖 , 聚乙烯亚胺 , 接枝度

CRITICAL NOTCH(CRACK)SIZE AS A CHARACTERISTIC PARAMETER EVALUATING CRYOGENIC BRITTLENESS IN LOW CARBON STEEL

LI Daoming YAO Mei Harbin Institute of Technology , Harbin , China Box 617 , Harbin Institute of Technology , Harbin , China

金属学报(英文版)

The effect of notch depth on the cryogenic fracture behavior has been studied using a low car- bon steel.An analysis was made for the fracture features at T_c~*(cryogenic brittleness-char- acteristic temperature)at which the facture load reaehes a valley value.Furthermore,accord- ing to the experimental results and engineering design practice,a concept of critical notch (crack)'size for cryogenic brittleness,a_c,as well as its limit value a_c~*,was put forward and recommended to be a basic characteristic parameter for controlling the brittleness. Mathematical derivation was carried out to give the expression of a_c and a_c~*,the reliability of which was verified by the modeling tests under both static and cyclic loading conditions.

关键词: low carbon steel , null , null

CHARACTER OF CARBON-DEPLETED REGIONS IN UNDERCOOLED AUSTENITE AND THERMODYANMICS OF BAINITIC TRANSFORMATION

YANG Quanmin KANG Mokuang Northwestern Polytechnical University , Xi'an , China YANG Quanmin , Dept.of Material Science and Engineering , Zhejiang University , Hangzhou 310027 , China

金属学报(英文版)

The chemical driving forces for the phase transformation from austenite in three different car- bon-depleted regions into ferrite with the identical composition have been derived respectively. The starting temperature of bainitic transformation,B_s,has also been calculated according to the shearing mechanism of bainitic transformation in carbon-depleted regions of austenite. The maximum driving forces for banitic transformation at B_s in both 3% Cr and the CrMo steels were obtained.It was shown that the proposed shearing mechanism of the bainitic trans- formation is thermodynamically possible.

关键词: bainitic , null , null

氧化环己烯连续进料下二氧化碳-环氧丙烷-氧化环己烯三元共聚物的合成

张亚明 , 高凤翔 , 周庆海 , 秦玉升 , 王献红 , 王佛松

应用化学 doi:10.3724/SP.J.1095.2014.40243

由于氧化环己烯(CHO)与二氧化碳的共聚反应速度比其与环氧丙烷(PO)快,这种竞聚率的差异导致一锅法所得的二氧化碳-环氧丙烷-氧化环己烯三元共聚物的组成难以稳定控制.为此本文在稀土三元催化剂下,采用氧化环己烯单体连续进料的方法合成了二氧化碳-环氧丙烷-氧化环己烯三元共聚物,催化效率可达575 g/(mol Zn h).三元共聚物的玻璃化转变温度随CHO含量升高而增大,当CHO的摩尔投料比从0.19增加到0.59时,玻璃化温度从44.3℃提高到70.1℃.CHO连续进料合成的三元共聚物的组成与投料比基本相近,且连续进料法所合成的三元共聚物只有一个玻璃化转变温度,而普通的一锅法所得的三元共聚物通常存在两个玻璃化转变温度,因此连续进料法是制备组成稳定的二氧化碳-环氧丙烷-氧化环己烯三元共聚物的有效方法.

关键词: 二氧化碳 , 氧化环己烯 , 环氧丙烷 , 连续进料

低碳低合金钢的静力韧度与断裂韧度

芦琳 , 李周波 , 毕宗岳 , 薛磊红 , 马璇

钢铁

采取静拉伸和平面应变断裂韧性测试方法,测量了S355,S275,Q345D,Q345E 4种低碳低合金钢自室温至-100℃的基本力学性能,包括屈服强度、抗拉强度、静力韧度、断裂韧度以及韧脆转变温度,试图寻找4种金属材料静力韧度和断裂韧度之间的关系;通过对200多组样品的试验结果进行分析,发现4种金属材料在其各自韧脆转变温度之上的静力韧度Uk和断裂韧度J02BL存在线性关系.

关键词: 静力韧度 , 断裂韧度 , 韧脆转变温度