A.X. Wu
,
Y. Xi
,
B.H. Yang
,
X.S. Chen
,
H.C. Jiang
,
null
,
null
,
null
,
null
,
null
金属学报(英文版)
A model GM (grey model) (1,1) for forecasting the rate of copper extraction during the bioleaching of primary sulphide ore was
established on the basis of the mathematical theory and the modeling process of grey system theory. It was used for forecasting the rate of copper extraction from the primary sulfide ore during a laboratory microbial column leaching experiment. The
precision of the forecasted results were examined and modified via "posterior variance examination". The results show that the
forecasted values coincide with the experimental values. GM (1,1) model has high forecast accuracy; and it is suitable for
simulation control and prediction analysis of the original data series of the processes that have grey characteristics, such as
mining, metallurgical and mineral processing, etc. The leaching rate of such copper sulphide ore is low. The grey forecasting
result indicates that the rate of copper extraction is approximately 20% even after leaching for six months.
关键词:
primary copper sulfide ore
,
null
,
null
李铂
,
周建江
,
夏伟杰
,
吴连慧
液晶与显示
doi:10.3788/YJYXS20142904.0605
直线是机载座舱显示画面中最基本的图元,其显示质量对于整个画面的显示效果影响较大,尤其是小角度下直线显示的“麻花”现象一直是影响显示效果的关键问题之一.为了提高小角度下直线的显示效果,本文提出了一种基于Wu算法的亮度渐变改进算法.该算法通过渐进地展现直线从轴方向上的亮度变化过程,减少亮度畸变,有效地改进了显示效果.通过Matlab仿真和FPGA实现,验证了该算法反走样后的小角度直线显示效果明显优于其他算法,而且结合中点画线法后,绘制时间与Wu算法相当.同时该算法还可改善大角度直线和圆弧的显示效果,消除了大角度直线的边缘锯齿,解决了圆弧在小角度部分的虚化问题.因此本文算法可用于对实时性和显示效果要求高的机载座舱显示系统,以缓解飞行员的视觉疲劳.
关键词:
座舱显示
,
反走样
,
改进Wu算法
,
小角度
,
FPGA实现
吴连慧
,
周建江
,
夏伟杰
,
陈雅雯
液晶与显示
doi:10.3788/YJYXS20153001.0163
对于光栅化的三角形,其边缘存在明显的锯齿现象,因此需要进行反走样处理.基于Wu直线反走样算法的思想,考虑了水平直线外侧直接添加插值点的算法和三角形三边外侧反走样的算法.综合两者的优点,在绘制光栅化的三角形的同时,边缘叠加Wu反走样直线,并考虑背景像素灰度值的作用.结果表明,改进的三角形光栅化的边缘反走样算法有效提高了三角形光栅化后边缘的显示效果,该算法计算量小,便于FPGA实现,可用于对图形显示质量要求很高的机载显示系统.
关键词:
反走样
,
Wu算法
,
光栅化
,
FPGA
胡跃鑫
,
冯玉林
,
姜伟
应用化学
doi:10.3724/SP.J.1095.2011.00521
采用不同尺寸的碳酸钙粒子增韧高密度聚乙烯,研究了不同温度下共混体系的临界粒子间距与碳酸钙粒子尺寸和含量之间的关系,确定了温度是Wu氏增韧理论临界粒子间判据适用性的重要影响因素.结果表明,在17℃下,临界粒子间距与碳酸钙粒子的尺寸和含量无关,该条件下Wu氏增韧理论临界粒子间距判据是适用的;而随着温度的升高,发现临界粒子间距依赖于碳酸钙粒子的尺寸,表明高温条件下,Wu氏增韧理论临界粒子间距判据不再适用.
关键词:
聚合物增韧
,
粒子间距
,
脆韧转变
材料科学技术（英文）
The structure, specific heat, magnetic and electrical properties of MnTe(1-x)Sb(x) (x=0, 0.1, 0.15, 0.2 and 0.25) alloys have been investigated. The MnTe(1-x)Sb(x) alloys crystallize in a hexagonal NiAs-type structure, and the impurity of MnSb phase appears when x >= 0.15. The MnTe(0.9)Sb(0.1) compound exhibits ferrimagnetic behavior with hysteresis loops even at 350 K, showing that the magnetic properties of MnTe compound are very sensitive to little compositional change. The ferromagnetism in the MnTe(1-x)Sb(x) alloys with higher Sb contents may be attributed to the impurity of MnSb phase. Energy dispersive X-ray spectroscopy analysis on the MnTe(0.9)Sb(0.1) compound indicates that Sb is very difficult to dope into the lattice of MnTe. So the anomaly of resistivity at 300 K of MnTe(0.9)Sb(0.1) and the peak of specific heat around 304 K of all the alloys are thought to be related with the antiferromagnetic interactions of MnTe-based lattice.
关键词:
Electronic transport property;Hysteresis loop;Specific heat;manganese telluride;semiconductors;ferromagnetism;scattering;exchange
Powder Diffraction
The structure transitions and phase relationships of DyFe(3-x)Al(x) compounds have been investigated by X-ray powder diffraction. Our XRD results show that each of the compounds with x <= 0.45 crystallizes in the rhombohedral PuNi(3)-type structure with space group R (3) over barm and Z=9; for the 0.8 <= x<1.0 compounds, each has a hexagonal structure of the CeNi(3) type with space group P6(3)/mmc and Z=6; and each of the samples with 0.45<x<0.8 is a two-phase mixture of the PuNi(3)- and CeNi(3)-type structures. The calculated XRD intensities of the DyFe(3-x)Al(x) compounds with x=0.2, 0.33, 0.4, and 0.45 indicate that Dy occupies the 3a and 6c sites, Fe and Al distribute randomly on the 18h site, and the 3b and 6c sites are exclusively occupied by Fe, which agrees well with those of our experimental XRD patterns. The XRD intensities of the DyFe(3-x)Al(x) compounds with x=0.8 and 1.0 have also been calculated and found to agree with the experimental results with Dy on the 2c and 4f sites, Fe and Al at the 12k site, and Fe at the 2a, 2b, and 2d sites. In the two-phase region with x=0.45-0.8, the values of unit-cell parameters and phase compositions are linearly dependent on the value of x, indicating that the two phases are constituted by the same composition x with different stacking arrangements. This abnormal two-phase equilibrium is further confirmed by the structural analysis of the DyFe(2.33)Al(0.67) (or x=0.67) sample. The samples with x=1.1 and 1.2 were also analyzed, and each found to be a mixture of more than two phases. (C) 2010 International Centre for Diffraction Data. [DOI: 10.1154/1.3507088]
关键词:
X-ray powder diffraction;DyFe(3-x)Al(x) system;structure change;anomalous phase composition;magnetic-properties;intermetallic compounds;al substitution;rare-earth;fe;dy6fe23;refinement;aluminum;dy2fe17;co
Journal of Magnetism and Magnetic Materials
The ingot of Fe-(18-x) at% Ga-x at% Al (3 <= x <= 13.5) alloys was prepared from high purity elements using a high vacuum arc melting system. The X-ray diffraction patterns indicated that the alloys were disordered bcc A2 structure. The magnetostriction of the alloys was measured and the effect of partial substitution of Ga with Al on the magnetostriction of the alloys was investigated. Fe-9 at% Ga-9 at% Al alloy, the optimizing magnetostrictive alloy was found in Fe-(18-x) at% Ga-x at% Al (3 <= x <= 13.5) alloys. The saturated magnetostriction of the directional solidification Fe-9 at% Ga-9 at% Al rod is up to 135 ppm for 0 MPa and 221 ppm for 53 MPa. It was found that the alloy has the high linearity of the magnetostriction curve, the low hysteresis and saturated magnetic field, which suggests the directional solidification Fe-9 at% Ga-9 at% Al alloy is a potential candidate for magnetostrictive actuator and transducer applications. (C) 2010 Elsevier B.V. All rights reserved.
关键词:
Fe-Ga-Al alloy;Magnetostriction;Microstructure;fe-rich portion;phase-equilibria;system;elasticity;stability
Lizhi CHENG
,
Wei FENG
,
Xinquan DONG
,
Kuichang BAI and Kaiyuan HE (Dept. of Materials Science and Engineering
,
Northeastern University Shenyang 110006
,
China)
材料科学技术（英文）
The formation of nonequilibrium phase by mechanical alloying (MA) of Fe and B powders in a high energy vibration ball mill has been made for Fe100-xBx system with x=15. 30, 35, 45,55 and 70. By using the X-ray diffraction, magnetic measurement and M6ssbauer spectrummethods, it was revealed that the structure of the MA product varies with milling time and B contents.
关键词:
Physical Review B
NdCo(12-x)V(x) (2.2 <= x <= 2.6) crystallizes in the ThMn(12)-type structure and exhibits an unusual jump in the magnetization at a critical field B(C) that decreases with increasing V content. It was intriguing that the magnetization of the bulk samples below B(C) was very close to that of YCo(12-x)V(x) with the same V content. To investigate the nature of the magnetic order in these materials we have carried out powder neutron diffraction measurements as a function of temperature and magnetic field on the NdCo(9.5)V(2.5) composition. In zero field we find that both the Nd and Co ions have substantial ordered moments (similar to 2.9 and 0.4 mu(B), respectively) at low temperature (4 K), with the moments coupled ferromagnetically (T(C)=180 K) and aligned along the c axis. On a loose powder an applied field of 4 to 7 T rotates the particles so the c axis aligns with the field, indicating a strong uniaxial anisotropy that renders the system Ising-like. However, we find the same in-field magnetic structure and essentially the same values for the saturated magnetic moments as those in zero field. Magnetization data on magnetically prealigned samples reveal that for fields applied parallel to the (easy) c axis the magnetization saturates below 0.5 T at a magnitude that is in very good agreement with the moments determined from neutron diffraction. For fields applied perpendicular to the c axis, on the other hand, the magnetization data show a two-plateau behavior, explaining the original magnetization data on randomly oriented powders. The strong dependence of the magnetization on the direction of the applied magnetic fields indicates an occurrence of the first-order magnetization process due to the competing magnetocrystalline anisotropies of the Nd and the Co sublattices and of the higher-order terms of the anisotropy energy.
关键词:
rare-earth;intermetallic compounds;thmn12 structure;transition;anisotropy;crystal;fe;substitution;ndco9.5v2.5;compound
郭可信
金属学报
<正> X射线在金属学及金属物理这一学科中的应用日益广泛,它已经是从事金属研究的科学工作者所不可缺少的工具.同时,金属X射线学也已经成为一门新的边缘学科分支,是金属学及金属物理专业的必修课程.但是,在这方面,迄今为止尚无一本我国科学工作者编写的教材或参考书,仅有的几种译本亦都有内容贫乏与过时的缺点.因此,许顺生同志著的“金属X射线学”的出版是值得欢迎的.本书的内容范围相当广泛,并且是此较全面的.全书共26章,可以粗略地分五个部分:第一部分(1—5章):基本理论,包括X射线物理及晶体学基础,X射线衍射的几何及强度理论;第二部分(6—10章):各种实验方法,如劳厄、周转晶体、粉末及小角度散射法;第三部分(11—15章):X射线晶体学的一
关键词:
