Solid-solution hardening and softening by Fe additions to NiAl

Solid-solution hardening in the case of a ternary alloy addition to a B2 compound with the triple defect structure has been investigated. The fact that the ternary element may occupy either of two sublattices or may affect the concentration of other types of point defects present in the material makes this a very interesting problem to consider. Ni-rich (40 at% Al), stoichiometric (50 at% Al), and Al-rich (52 at% Al) alloys were doped with up to 12 at% Fe. Lattice parameter, bulk density and hardness measurements were performed on samples quenched from 1000 °C. It was found that solid-solution softening actually occurs in the Ni-rich alloys, while hardening was observed in the stoichiometric and Al-rich alloys. The vacancy concentration was determined from the experimental data, and the site occupancies of the Fe atoms were estimated from a thermodynamic model. Through careful consideration of all point defect concentrations the solid-solution hardening and softening behaviors could be effectively rationalized.     

ZA27合金金属型铸造时的凝固特性,伴生缺陷和壁厚效应

金属型铸造是ZA27的主要铸造方法之一。本文试验研究了ZA27合金金属型铸造时的凝固特性、伴生缺陷和壁厚效应。结果表明,ZA27合金在金属型中以糊状方式凝固,铸件易于产生缩松和比重偏析,铸件的力学性能对于壁厚有明显的敏感性。     

Defect structure and chemical diffusion in nickel sulfide β-Ni3S2

The chemical composition, defect structure, and diffusion in nickel sulfide -Ni₃S₂ have been investigated in H₂S-H₂ mixtures containing between 1 and 65% H₂S between 560 and 700°C. Gravimetric, density, and X-ray studies were carried out. In the thermodynamically stable compound the ratio of Ni/S varied between 1.3 and 1.75. The X-ray examination showed a step change in the lattice parameter at the Ni/S ratio 1.4. A linear dependence of the density values (between 5.5 and 6.2 g/cm³) on the composition was observed. On the basis of the chemical composition and density measurements the number of nickel and sulfur atoms in 1 cm³ were determined. It has been shown that the Ni₃S₂ phase is defected in both anion and cation sublattices and that its chemical formula may be described as follows: Ni_3±yS_2x, where y 2x. It has been found that in the mixture containing 10% H₂S the process of defect formation is determined by their diffusion in the sulfide. The temperature dependence of the diffusion coefficient is described by the equation D = 13.15 exp(-30,000/RT) cm²/sec. No dependence of D on the sulfur partial pressure was observed, but this may be due to the relatively large uncertainties in the measurement of the diffusion coefficients.     

挤压铸件的热处理起泡缺陷研究

热处理起泡是挤压铸件常见的缺陷之一,它与挤压方式、工艺、模具等有关。对直接挤压铸件,只要不用油剂涂料,解决好排气,均能顺利进行固溶热处理,对于间接挤压铸件,还要设计好其内浇道系统,并严格控制好液态金属充型速度,防止夹杂等,也是可以进行固溶热处理的。     

四辊热轧机支承辊表面裂纹的修复

本文介绍了用局部不接触法修复轧机支承辊表面裂纹的方法。实践证明,这种方法操作简单、节省金属、效果良好、可在现场进行,而且具有较大的经济效益。     

机械球磨Al-10%Ti粉末的组织和热稳定性

研究了机械球磨方法制备的Al-10%Ti混合粉末的组织和热稳定性.结果表明:在球磨作用下,Al, Ti粉末的颗粒尺寸得到有效细化,并且球磨时间越长,Al/Ti粉末储备能量越大,生成Al-Ti金属间化合物所需的反应激活能越低,内能的增加和扩散能力的提高是由于机械球磨导致了大量的晶格缺陷;Al-10%Ti混合粉末反应烧结后相互扩散形成的最终产物是DO22-Al3Ti.     

机床导轨面缺陷修复技术的分析

通过对机床导轨面缺陷修复的几种传统焊补方法的介绍及对各种方法不同特点的分析,确定机床导轨面缺陷修复局限性的存在原因.同时,对一种新出现的铸造缺陷修复技术及其设备铸造缺陷修补机,进行了实践操作实验和试棒的显微组织分析,说明用铸造缺陷修补机修复机床导轨面缺陷是符合质检标准的,证明了缺陷修补机在铸件缺陷修复方面是值得推广的一项新技术.     

结合肤色分割与平滑的人脸图像快速美化

目的 针对目前人脸图像美化算法存在的对于细节丰富的眼睛和头发等区域处理过度平滑,美化后的图像整体美化效果较差等问题,提出一种基于肤色分割与平滑人脸图像的美化方法。方法 首先对脸部瑕疵特性,用双指数边缘保护滤波器平滑人脸图像的瑕疵,与此同时很好保持图像边缘信息;再通过利用色度直方图自适应快速检测、修正、分割肤色区域;然后利用拟合高斯羽化皮肤区域生成蒙版,融合平滑图像和原图像,保留图像头发背景等细节信息;最后基于人像美感标准,对皮肤亮度通过拟合log曲线实现快速自适应调整人脸图像亮度,增强眼睛等细节,从而快速实现人脸图像美化方法。结果 通过与其他人像美化算法相比较,在保留边缘方面,该算法更有效地对皮肤边缘上的瑕疵进行平滑,达到更好地美化人脸图像;而在时间复杂度方面,相对于前人的算法,计算速度快12倍,实现快速美化人脸图像。结论 该算法适应能力较强,对大部分人脸图像的脸部瑕疵完美去除的同时达到背景信息不变,肤色美白自然,使整体美化效果显著;尤其是细节丰富的边缘区域平滑适度,具有一定的实用性。     

Screen‐based color vision test for digital quantification of deutan color defects using a color‐calibrated monitor

Display technologies are used in various industries. However, few studies on color vision testing using self‐luminous displays are reported. In this study, a screen‐based color vision test, termed the digital color vision test (DCVT), is developed on a color‐calibrated monitor. A control bar is adjusted by the observer to build just noticeable chromatic difference ellipses in CIE u′v′ chromaticity diagram, which indicate the capabilities of subjects' color visions. Ten color‐normal observers and 13 deutan observers participated in the psychophysical experiments. The observers also performed the other two typical diagnostic tests (D‐15 and anomaloscope). Results from the experiment using the adjustment psychophysical method for digital quantification of deutan color vision defects are presented. It is found that the diagnosis accuracy of the DCVT is approximately equivalent to those of D‐15 and anomaloscope tests.     

十二孔闸改建工程抢工措施探讨

十二孔闸改建工程因＂引黄补淀＂要求,工期由原来设计的10个月压缩为两个半月,改建工程项目部克服多项困难组织抢工,在抢工过程中出现一些不足之处给抢工任务造成不利影响,该文着重分析抢工措施中的不足之处及提出应该注意的问题。