Author J.H. Lee 1)
,
K.B. Yoon2)
,
Y.J. Kim3)and U.B. Baek4) 1) Engineering Research Department
,
Korea Institute of Nuclear Safety
,
P.O. Box 114
,
Yoosung
,
Taejon 305600
,
Korea2) Department of Mechanical Engineering
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Chung Ang University
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221 Huksuk
,
Dongjak
,
Seoul 156756
,
Korea3) Department of Mechanical Engineering
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Sungkyunkwan University
,
300 Chunchun
,
Jangan
,
Suwon 440746
,
Korea4) Failure Prevention Research Center
,
Korea Research Institute of Standards and Science
,
P.O. Box 102
,
Yoosung
,
Taejon 305600
,
KoreaManuscript received 18 October 1998
金属学报(英文版)
Most of the assessment equations for Ct which is a wellknown fracture parameter characterizing high temperature crack growth rates, have limited applicability to constant load conditions after sudden loading. However, crack growth due to creep can also occur under load varying conditions when load rising time is so long that accumulated creep deformation near the crack tip is not negligible.In this paper, the estimation equation of the Ctparameter which can be applied to the case of slow load rising, i.e., (Ct)r, is explained. And the correlation between (Ct)r at the end of the load increasing period and Ct at the beginning of the succeeding load hold period is discussed. Finite element analyses of several cases with various loading conditions were performed and results were presented to show the effectiveness of the proposed Ct estimation scheme. The general applicability of the equation is also discussed.
关键词:
creep
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null
,
null
,
null
,
null
,
null
李亚敏
,
张星
,
王阿敏
,
刘洪军
材料热处理学报
采用直接化学复合镀法在ZL102合金表面制备了Ni-P-SiC复合镀层,经不同温度热处理后,利用XRD、DSC、扫描电镜等对复合镀层的结构和形貌进行了分析,并对镀层的结合力、显微硬度、耐蚀性及耐磨性等进行了测试.结果表明:镀态镀层由晶态相和非晶态相组成,热处理过程中非晶态相向晶态转化;镀层的显微硬度随热处理温度的升高呈先升后降的趋势,在400℃时达到最大值1395.28 HV;镀层经400℃×l h热处理后,镀层中的镍和磷原子向铝基体中扩散,复合镀层与基体结合良好,耐磨性和耐蚀性较基体有很大程度的改善,但热处理后镀层的耐蚀性与镀态的相比有所降低.
关键词:
ZL102铝合金
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热处理
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Ni-P-SiC镀层
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结构
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性能
Solid State Communications
Considering the image potential, we calculate the binding energies of a shallow donor impurity placed on the centre of a quantum box using the variational approach. The results we have obtained show that there is a great difference of the effects of image potential between the cases including impurity ion image potential and including the image potentials of impurity ion and electron simultaneously. The results also show that the image potential is important, especially when the dimensions of quantum box become small.
关键词:
well;gaas-ga1-xalxas;states
L. H. Lang
,
D. C. Kang
,
S. H. Zhang
,
Z. R. Wang
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S. J. Yuan
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K. B. Nielsen and J. Dancket 1) Department of Materials Engineering
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Harbin Institute of Technology
,
Harbin 150001
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China 2) Aalberg University
,
Denmark
金属学报(英文版)
In this paper, the forming features of tapered rectangular box during hydrodynamic deep drawing are studied by means of FEM.The effect rules of square blank corner corner amount on body wrinkling are recognized and corresponding methods are discussed. At last, the results of FEM are verified by experi- ment.
关键词:
sheet metal forming
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null
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null
Qunqiang FU
材料科学技术（英文）
At first, a series of finite element method (FEM) simulation tests were used to find the critical forming conditions of hot-galvanized sheet steel during the rectangular box drawing processing when constant blank holder forces were applied. According the test results, the reasonable alteration scope of initial variable blank holder force (VBHF) was as 1.9~2.3 T. Then, based on the test productions of blank holder force, 12 typical VBHF curves were applied to perform the simulation tests by the simulation software of DYNAFORM. The simulation test results showed that VBHF had great effects on drawing formability of hot-galvanized sheet steel during the rectangular box drawing. However, the different VBHF curves were applied to control the whole drawing and it would get great different effects. At the same tine, the VBHF had great effects on the maximum thick thinning ratio, but had little effect on the maximum thick incrassation ratio. So, reasonable application of the VBHF would greatly decrease the fractures. When the VBHF profile is taken as curve L, the best effect of drawing formability could be obtained. When curve I is used, contrary effect could be gotten. The other types of curves would cause effects between above two types of VBHF curves. Finally, the actual tests were applied to check the validity of the FEM simulation tests. The results show that the FEM simulation tests are good ways for predicting and optimizing the VBHF.
关键词:
Drawing process
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变压边力
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热镀锌钢板
郑仁蓉
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杨盈春
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陆祺
,
朱顺泉
原子核物理评论
doi:10.3969/j.issn.1007-4627.2004.02.024
将两准粒子加轴对称转子模型扩展到三轴形变,对奇奇核102Rh的旋称反转进行了研究和分析,结果表明,可能的旋称反转机制 (即低K 空间n-p相互作用和科氏力的相互竞争),对于A=100质量区奇奇核也是适用的,三轴形变可以明显地改进能谱的振荡特性.
关键词:
奇奇核
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旋称反转
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两准粒子加三轴形变转子模型
Journal of Alloys and Compounds
The subsolidus phase relations in the system La2O3-B2O3-P2O5 were investigated. The system can be divided into 12 three-phase regions. There are nine binary compounds and one ternary compound in this system. The ternary compound La7O6(BO3)(PO4)(2) has a monoclinic structure, space groups P2(1)/n, with lattice constants a = 7.0172 Angstrom, b = 17.9125 Angstrom, c = 12.6500 Angstrom, beta = 97.516 degrees, V = 1576.39 Angstrom(3), and Z = 4.
关键词:
La2O3-B-3-B2O3-P2O5 system;phase relations;ternary compounds
李芳积
,
曾兴兰
,
朱英江
稀土
doi:10.3969/j.issn.1004-0277.2002.06.001
阐述了L102捕收剂在稀土浮选生产上的应用条件和应用效果.浮选捕收剂L102与Na2SiO3*nH2O和L108组合配方,在矿浆pH值=7～9和温度为33～60℃条件下,对重选摇床中矿只需要一次粗选一次精选作业,则可生产出含60～68%(REO),实际回收率82～90%优质商品精矿.药剂总单耗较原用药剂降低了1/3.控制好浮选给矿品位是获得优质精矿、减少药剂单耗、降低生产成本、提高生产效率的重要因素.
关键词:
稀土
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捕收剂
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L102
陈玮
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姚长江
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尹周澜
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刘新红
耐火材料
doi:10.3969/j.issn.1001-1935.2008.04.009
分别对反应前后的p-Al2O3进行XRD及SEM分析,确定反应前后Al2O3的物相及显微结构变化;测定加入添加剂前后浆体温度与时间的关系,从而确定添加剂对p-Al2O3水化速度的影响;测定加入添加剂前后浆体的黏度变化,从而测定出添加剂对p-Al2O3水化过程的影响.结果表明:1)p-Al2O3属于无定形态;2)在没有添加剂的情况下,p-Al2O3的水化速率很快,同时释放出大量热量,水化产物主要是一水软铝石、三水铝石和拜耳石;3)加入碳酸钠及六偏磷酸钠的混合物为添加剂后,p-Al2O3的水化速率显著降低,释放出的热量显著降低,水化产物主要是一水软铝石.
关键词:
p - 氧化铝
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水化硬化
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不定形耐火材料
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结合剂
