Shihong LI
,
Shaoyun FU
,
and Benlian ZHOU (Int. Centre for Mater. Phys.
,
Institute of Metal Research
,
Chinese Academy of Science
,
Shenyang
,
110015
,
China)Qiyun ZENG
,
and Xianrong BAO (Institute of Applied Ecology
,
Chinese Academy of Sciences
,
Shenyang
,
11
材料科学技术（英文）
A new technique has been developed for flattening circular natural bamboo culm to plate form for remarkably enhancing its mechanical properties, The enhanced bamboo, cheaper than Al, is then used to reinforce an aluminum alloy for civilian applications. The properties of the composite are greatly enhanced compared to those of the Al alloy. The Al protects bamboo from bioerosion and improves hygroscopicity
关键词:
SU Zuwu MENG Guowen GUO Hongzhen LIU Jianchao YAO Zekun Northwestern Polytechnical University
,
Xi'an
,
ChinaYANG Zhaosu HU Zongshi Baoji Non-Ferrous Metals Mill
,
Baoji
,
China
金属学报(英文版)
The formation reason and elimination method of non-uniform microstructure defects in Ti al- loy TC11 bar have been studied.The coagulating and coarsening into block of the part of grain boundary α and secondary α seem to be caused by the ingot cogging and initial forging temperature in the β region as well as no more enough deformation and uneven distribution. The grain α,elongated α and blocky α may be finally eliminated by adopting the technique of (α+β)thermomechanical processing+β processing,W.Q.+recrystallization annealing,A.C., thus the size of uniform and fine equiaxed α structure is believed to be reduced to 1.9258μm.
关键词:
TC11 Ti alloy
,
null
,
null
,
null
Transactions of Nonferrous Metals Society of China
The corrosion behavior of LY11 aluminum alloy in acid, alkaline and neutral soil after burying for 1, 3 and 5 a was studied. It is shown that localized corrosion is the major behavior of LY11 aluminum alloy in soil, and corrosion of LY11 depends on the soil texture: severe corrosion occurs in the heterogeneous alkaline and acid soil, and slight corrosion occurs in homogeneous neutral and acid clay soil.
关键词:
LY11 aluminum alloy;soil corrosion;corrosion behavior
C.L. Chu
,
G.J. Shen
,
S.D. Wang
,
B. Li
,
S.G. Zhang and Z.D. Yin(BOX 433
,
School of Materials Science and Engineering
,
Harbin Institute of Technology
,
Harbin 150001
,
China)(Analysis and Testing Center
,
Southeast University
,
Nanjing 210018
,
China)(Research Institute of Electric Light Source Materials
,
Ministry of Light Industry
,
Nanjing 210015
,
China)
金属学报(英文版)
From the orientation relationship between "Ti11Ni14" phase and matrix phase (B2),the accurate molecular formula of "Ti11N14" phase has been derived in this paper. The results also show that the rhombohedral unit cell of the "Ti11Ni14" phase includes six Ti atoms, seven Ni atoms and one vacancy, belonging to space group R3.
关键词:
TiNi
,
null
,
null
杨晓梅
,
徐竹生
,
马怀军
,
徐云鹏
,
田志坚
,
林励吾
催化学报
在水-丁醇两相介质中合成了SAPO-11和MgAPO-11分子筛. 水-丁醇两相介质有利于在SAPO-11中引入更多的Si, 从而产生较多的酸性位,以所得SAPO-11为载体的Pt催化剂在正十二烷临氢异构化反应中表现出较高的催化活性. 相反,水-丁醇两相介质不利于Mg进入分子筛骨架,导致MgAPO-11上的酸性位减少,Pt/MgAPO-11催化剂的催化活性降低.
关键词:
SAPO-11
,
MgAPO-11
,
水-丁醇两相介质
,
铂
,
正十二烷
,
临氢异构化
Journal of Alloys and Compounds
The structural and magnetic properties of the ternary GdFe11Re compound were investigated by means of X-ray diffraction analysis and magnetic measurement. GdFe11Re crystallizes in a tetragonal structure with space group 14/mmm. The lattice parameters are a=8.5339 Angstrom and c=4.7603 Angstrom. The results of Rietveld refinement of powder XRD data revealed that the Re atoms preferentially occupy the 8i site. This is basically due to the atomic size effect dominating over the enthalpy effect. Magnetic measurements indicated that the GdFe11Re compound is ferromagnetic with a Curie temperature of 518 K. It was found that the easy magnetization direction of GdFe11Re is along the c-axis. The saturation moment and the magnetocrystalline anisotropy field of the GdFe11Re compound at 5 K are 16.28 mu(B)/f.u. and 56.4 kOe, respectively. (C) 2002 Elsevier Science B.V. All rights reserved.
关键词:
rare earth compounds;crystal structure;magnetic measurements;ternary
Journal of Applied Physics
The effects of substitution of Si for Co on the crystal structural stability and magnetic properties of NdCo11-xSix compounds have been studied. X-ray diffraction and magnetic measurement show that the single phase region can be expressed as NdCo9.8-9.2Si1.2-1.8 other than NdCo9Si2. X-ray-diffraction study indicates that the compounds adopt the tetragonal BaCd11-type structure. The magnetic properties of a series of NdCo11-xSix solid solutions have been studied by magnetic measurement. Our investigations show that the Curie temperature of NdCo11-xSix increases drastically from 528 K (x=1.8) to 833 K (x=1.2) as the Si content decreases, The Co magnetic moment reaches a maximum between NdCo9.8Si1.2 and NdCo9.6Si1.4, and decreases with the further increase in x. The substitution of Si for Co in NdCo11-xSix leads to a contraction of lattice constant a by 0.2%, c by 0.2%, and a consequent reduction of the unit-cell volume by about 0.6%. The Rietveld refinement results show that the silicon atoms preferentially occupy the 8(d) sites. The occupation of 8(d) sites by proper amount of Si will shift the Fermi level E(F) upward and to a valley with a lower local density of states in NdCo11-xSix compounds, which is favorable for the stability of the BaCd11-type structure. (C) 1996 American Institute of Physics.
关键词:
electronic-structure;series;nd
Journal of Physics-Condensed Matter
Spin-reorientation transitions in Nd1-xPrxFe11Ti compounds have been studied by measuring the temperature dependence of the a.c. susceptibility and the magnetization. The angular dependence of the magnetization on the applied field was measured on magnetically aligned samples in a SQUID magnetometer. In NdFe11Ti, the easy magnetization direction at room temperature was determined by x-ray diffraction to be the c-axis; at low temperatures, the SQUID measurements show a cone to be stable. At temperatures between 170 and 250 K, the SQUID measurements display more complex behaviour, which is attributed to the occurrence of a first-order magnetization process in this compound. The easy magnetization direction of Nd1-xPrxFe11Ti compounds with 0.2 less than or equal to x less than or equal to 0.4 changes from easy c-axis at high temperatures via a basal plane to easy cone at low temperatures. The magnetic phase diagram of the Nd1-xPrxFe11Ti system is given. For PrFe11Ti, the critical field of the FOMP transition below 230 K, which corresponds to the critical temperature of the first-order transition, and the anisotropy fields at temperatures ranging from 240 to 300 K have been further investigated by means of the SPD technique.
关键词:
anisotropy;curve;pr;nd;tb
张成路
,
申洪江
,
邹立伟
,
许永廷
,
广东
,
李元东
,
王杨
,
王利东
应用化学
doi:10.3969/j.issn.1000-0518.2009.10.011
以3,5-二甲氧基苯甲酸(1)为起始原料, 经过甲醇酯化、氢化铝锂还原、四溴化碳溴代和Wittig-Horner反应,高产率的合成了Wittig-Horner试剂(5). 化合物5与对羟基苯甲醛(6)的羟基保护产物(7)偶联得到化合物(8),后者经去甲氧基亚甲基保护和仿生氧化偶联反应成功地全合成了(E)-脱氢二聚白藜芦醇-11,11′,13,13′-四甲醚(10). 通过~1H NMR、~(13)C NMR、IR、HRMS等测试技术确定化合物10为二聚芪类化合物(E)-脱氢二聚白藜芦醇-11,11′,13,13′-四甲醚,总收率48.93%.
关键词:
白藜芦醇
,
氧化偶联
,
二聚芪类化合物
,
(E)-脱氢二聚白藜芦醇四甲醚
Applied Physics Letters
We have succeeded in synthesizing PrFe11V1-xTix (x=0.2-1) compound and their nitrides with the ThMn12-type structure. The phase formation and magnetic properties have been investigated by x-ray diffraction, differential thermometric analysis, and magnetic measurement. The stable temperature range of the 1-12 phase for PrFe11V1-xTix alloys has been determined as a function of Ti content. PrFe11V compounds with the ThMn12-type structure do not exist and PrFe11Ti compounds with the TnMn(12)-type structure are obtained by annealing in a narrow temperature range between 1303 and 1383 K. Furthermore, 1-12 phase with the ThMn12-type structure can be obtained at lower temperature and wider temperature range with decreasing Ti content x (0.2 less than or equal to x less than or equal to 1). PrFe11V1-xTixNy with x=0.2-1 has a T-c of about 730-785 K, B-a larger than 8 T and M-s in the range 144-148 emu/g. These intrinsic magnetic properties are highly favorable for permanent magnet applications. As a preliminary, an intrinsic coercivity of 5.4 kOe is obtained for PrFe11V0.5Ti0.5Ny at room temperature by using mechanical alloying technique. (C) 1997 American Institute of Physics.
关键词:
