L.Chen
,
Z.Y.Liu
,
D.C.Zeng
,
W.Q.Qiu
,
Z.H.Yuan
,
S.S.Lin
,
H.J.Hou
金属学报(英文版)
DLC super-hard films have been deposited on the substrates of single crystalline Si, pure Ti and stainless steel 18-8 by a method of vacuum cathode arc deposition (VCAD). The composition, microstructure and micro-hardness of the films have been studied in this paper. The results indicate that hardness of the DLC films is different on the different substrates. Hardness of the films increases with decreasing in surface roughness of the films. The maximum value of micro-hardness belongs to the DLC films deposited under the hydrogen pressure of 0.35Pa and the neqative bias of 100V.
关键词:
DLC films
,
null
,
null
L.Chen
,
Y.F. Han
,
C.H Tao and M.L. Xie(Beijing Institute of Aeronautical Materials
,
Beijing 100095
,
China Manuscript received 26 August 1996)
金属学报(英文版)
The microstructures of NiAl(Co)-TiB_2 composite prepared using exothermal dispersion (XD) method have been studied by optical microscopy, XRD, EDS, and TEM The results show that, TiB_2 paritcles are typically single crystal, and fairly uniformly distributed. The matrix mainly consists of β-NiAl phase, Ll_2γ′Ni_3Al phase and δ-Ni_3Al phase. The δNi_3Al has a fcc crystal structure with lattice parameter a=1.068nm.The data of compressive testing at room temperature show that the room temperature ductility of NiAl(Co) matrix composite is much better than that of stoichiometric NiAl.
关键词:
:intermetallic compound
,
null
李开明
,
李亚洲
,
冯维贵
,
林长
量子电子学报
doi:10.3969/j.issn.1007-5461.2007.05.014
采用非线性反馈控制,用附加了带参数的正弦项对Chen系统进行了有效的控制.随着参数k的逐渐增大,系统的动力学行为呈现出一系列的变化.数值研究结果表明:随控制参数的增大,驱动信号的强度渐大,混沌系统由混沌运动到周期轨道,最终到一相点.
关键词:
混沌
,
Chen系统
,
不动点
,
Lyapunov指数
,
反馈控制
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
娄玲
,
尹静波
,
高战团
,
梁奇志
,
董丽松
,
陈学思
,
景遐斌
高分子材料科学与工程
从左旋L-乳酸经高温催化反应得到低聚L- 乳酸,再经高温裂解减压蒸馏制得单体L-丙交酯(LLA),理论收率高达80%以上.LLA经纯化,再以辛酸亚锡为催化剂开环聚合得到聚L-丙交酯(聚L-乳酸,PLLA),其粘均分子量可达到40万.
关键词:
L-丙交酯
,
聚乳酸
,
生物降解材料
潘川
,
李正邦
,
田志凌
,
梁东图
,
褚武扬
,
乔利杰
钢铁研究学报
奥氏体不锈钢308L和347L的焊缝金属能发生氢致滞后断裂,而且比304L母材更敏感.用单边缺口试样动态充氢法测出的氢致滞后断裂门槛应力强度因子KIH随可扩散氢浓度C0的对数而线性下降.3种材料氢致滞后断口的形貌与KI以及C0有关,当KI较高或C0较小时是韧窝断口;当KI较低或C0较高时是脆性断口.
关键词:
奥氏体不锈钢
,
焊缝金属
,
氢致滞后断裂
王华林
,
方大庆
,
史铁钧
,
翟林峰
高分子材料科学与工程
聚D,L-乳酸(PDLLA)的合成方法主要有直接法和间接法两种.间接法合成PDLLA的关键在于中间体D,L-丙交酯(DLLA)的制备.文中以D,L-乳酸为原料,在催化剂辛酸亚锡(ZnOct2)的作用下,合成DLLA.研究温度、压力、时间等因素对DLLA产率的影响,利用DSC、XRD、IR等分析测试技术对DLLA的性能和结构进行相关的测试和表征.研究结果表明,在反应体系中加入乙二醇作为稀释剂,能降低DLLA的馏出温度,避免了DLLA在蒸馏过程中产生炭化现象,并使DLLA的平均产率由36.8%提高至51.3%.
关键词:
聚D,L-乳酸
,
D,L-丙交酯
,
合成
李建华
,
樊泽兴
,
赵远峰
物理测试
针对国内球扁钢、L型钢生产效率及成材率偏低的问题,从球扁钢、L型钢生产线设备选型与布置、轧件断面冷却不均、冷床预弯等方面围绕球扁钢、L型钢的长尺生产进行了技术分析。采用推钢式加热炉取代步进式加热炉、BD1＋BD2＋3机架水平连轧的布置形式、终轧后设置喷雾嘴对内侧表面进行强制冷却以及增加冷床预弯功能,可有效解决球扁钢、L型钢的长尺生产问题。
关键词:
球扁钢
,
L型钢
,
长尺生产
