钆对Mg-8Li-4Zn-xGd合金铸态组织与力学性能的影响

采用锂盐熔剂保护熔铸Mg-8Li-4Zn-xGd(x=1,3,5)合金铸锭,研究钆含量对铸态合金组织和力学性能的影响。结果表明:Mg-8Li-4Zn-xGd合金基体由α-Mg(HCP)和β-Li(BCC)双相构成。随着钆含量的增加,Mg5Gd共晶相和Zn12Gd化合物相逐渐连成网状,将基体α+β双相隔离成20~40μm的等轴状或类似于铸铁中的共晶团状,可有效细化α-Mg相和连续的β-Li相;组织中大颗粒Mg2Zn11相弥散分布在β-Li相内,Mg51Zn20相分布在α-Mg晶界处;锌元素还可以在β-Li相中析出细小弥散分布的MgZn相,其数量随钆含量的增加而增加,可直接弥散强化β-Li相。此外,锌和钆对合金硬度的影响较大,随着钆含量的增加,合金的抗拉强度提高,但伸长率降低。     

基于区域特征和质心关系的两步法阀板检测

针对冲压阀板中毛刺、冲压孔堵塞等缺陷的检测问题,提出了一种基于面积特征的通孔数目检测和基于质心关系的快速模板匹配检测的两步视觉检测方案。首先采用通孔数检测初步判定零件是否存在冲压孔堵塞缺陷,之后采用模板匹配精确检测边缘毛刺缺陷。利用区域面积特征实现通孔数检测;提出了一种限定条件的最小二乘法圆拟合方法和一种基于圆心特征的快速模板匹配方法,实现边缘毛刺等缺陷的精确检测。实验结果表明,这种两步检测方案检测速度快精准度高,能够满足阀板生产线的检测要求。     

低压环境下航空电缆材料燃烧特性的研究

在高高原实验室(61 kPa、4 290 m)和广汉实验室(96 kPa、520 m),分别开展常低压条件下FXL型航空电缆的对比燃烧实验。通过热辐射加热箱、烟密度及成分测试仪和氧指数仪等设备,测量点燃时间、烟密度、质量损失速率和CO、CO2及O2等浓度变化。实验结果表明:在96 kPa和61 kPa两种实验环境下,低压下最小点燃时间及温度的数值更大,两者的温度和时间差分别为15℃和4.8 s;烟密度曲线快速升高后趋于平衡,61 kPa条件下的发烟量小于96 kPa;O2体积浓度随着加热时间先下降后升高,而CO2的变化趋势相反。在61 kPa条件下,CO曲线会出现双峰现象且更明显;随着氧浓度增加,质量损失速率加快且呈线性关系;压力因素对燃烧影响减弱且燃烧持续时间差值变小。研究结果揭示了低压环境对航空电缆的燃烧影响,为增强航空安全提供参考。     

Environmental Engel curves in Italy: A spatial econometric investigation

This paper adopts a spatial econometric methodology to investigate the relationship between income and direct household emissions in Italy, as posited by the environmental Engel curve. The spatial approach is motivated by an expanding strand of studies that have detected significant spatial interactions in household-polluting activities responsible for the generation of direct household emissions. Our results suggest the presence of significant spatial dependence for household emissions emerging among regions. At the same time, increases in the level of income do not seem to be coupled with a higher demand for environmental quality by Italian households.     

SPS制备Ti-18Mo-xSi合金的高温氧化行为研究

采用高能球磨-放电等离子烧结技术制备了Ti-18Mo、Ti-18Mo-0.5Si、Ti-18Mo-1Si和Ti-18Mo-2Si4种合金,研究了Si含量对合金微观结构、相组成的影响及700和800℃空气中合金的氧化行为。结果表明:烧结合金中主要由Ti(Mo)固溶体组成,添加Si元素合金出现了Mo_5Si_3相。在700和800℃空气中分别氧化100 h后,合金表面主要有TiO_2、Ti O、MoO_2和MoO_3相,添加Si元素的合金氧化后还出现了SiO_2相。4种合金在700℃下的氧化增重明显小于800℃下的氧化增重,Ti-18Mo-0.5Si合金在700和800℃下平均氧化速率分别为0.09和0.10 g·(m~2·h)~(-1),其抗氧化性明显优于其他合金。     

Development of Whole and Ground Seed Near-Infrared Spectroscopy Calibrations for Oil,Protein, Moisture,and Fatty Acids in Salvia hispanica

Chia (Salvia hispanica) is an ancient crop that has experienced an agricultural resurgence in recent decades owing to the high omega 3 fatty acid (ω-3) content of the seeds and good production potential. Analysis of 563 lots of chia grown in Kentucky and 10 lots from Arizona, Australia, Mexico, and Peru was performed. All of these lots were assessed for fatty acid, oil, and protein content, while a subset of 120 samples were assessed for amino acids, fiber, minerals, and trace elements. The mean oil content was 31.3%, ranging from 21.4% to 35.3%. The protein content averaged 22.8%, ranging from 18.2% to 28.2%, and the ω-3 FA α-linolenic acid (ALA) averaged 61.3%, ranging from 33.9% to 69.9%. Using these seed lots, nondestructive near-infrared spectroscopy (NIRS) calibrations were developed for whole and ground seed oil, protein, moisture, and the six major fatty acids. The R² and SE of cross-validation (SECV) values for oil were 0.78 and 0.95, respectively, while those for protein were 0.75 and 1.05, respectively. The NIRS calibrations for fatty acid had R² and SECV greater than 0.6 and less than 10% of actual values for all major fatty acids, respectively. An R² of 0.99 was established for moisture content of whole seeds within the range of 3–10% moisture content. The precision and accuracy of these calibrations is adequate for use by breeders, growers, and food quality experts to quantitatively assess these major constituents without the need for costly and time-consuming chemical analysis.     

华宁KTC101控制系统应用和故障处理

神东公司大多数综采工作面在使用华宁KTC101控制系统,以实现对运输设备的集中控制。首先介绍了华宁KTC101控制系统在神东公司综采工作面的设备组成和各部分的作用及运行方式,并阐述了该系统在综采工作面的布局和运输设备的参数设置。通过对其控制原理和实际工作时常用方式的分析,总结了一些常见的控制器、接触器、扩音电话故障处理方法,可以使操作人员更加熟悉设备性能,极大提高设备自动化程度。     

基于稳定固溶体团簇模型的无扩散阻挡Cu合金薄膜的成分设计

随着超大规模集成电路的发展,器件特征尺寸不断缩小,必然会出现Cu互连扩散阻挡层厚度无法进一步减小等瓶颈问题。因此,开发新型无扩散阻挡层Cu合金薄膜(Cu种籽层)势在必行。该新型互连结构在长时间的中高温(400~500℃)后续工艺实施过程中,需同时具备高的稳定性(不发生互扩散反应)和低的电阻率。基于此,首先综述了目前无扩散阻挡层结构的研究现状及问题,然后对基于稳定固溶体团簇模型设计制备的无扩散阻挡Cu-Ni-M薄膜的研究工作进行了梳理,通过多系列薄膜微观结构、电阻率及稳定性的对比,深入探讨了第三组元M的选择原则及其对薄膜热稳定性的影响。为进一步验证稳定固溶体团簇模型的有效性,对第二组元的变化进行了相关讨论。结果证实,选取原子半径略大于Cu、难扩散且难溶的元素作为第三组元M,薄膜表现出良好的扩散阻挡能力;当M/Ni=1/12,即合金元素完全以团簇形式固溶于Cu基体时,薄膜综合性能达到最优,能够满足微电子行业的要求。所有研究表明,稳定固溶体团簇模型在无扩散阻挡层Cu合金薄膜的成分设计方面十分有效,该模型也有望在耐高温Cu合金及抗辐照材料成分设计方面推广使用。     

Effect of particle size and grain composition on two-dimensional infiltration process of weathered crust elution-deposited rare earth ores

The two-dimensional infiltration experiment was carried out by means of digital image technology. The evolution process of the wetting body was described. The wetted front distance and the time show a very significant power function relationship. The horizontal wetted distance is larger than the vertical wetted distance in the initial stage. Then, the vertical distance of the wetted body gradually approaches to the horizontal distance. The infiltration distance decreases as the content of fine particles increases. The wetted front migration rate curve shows a three-stage change law, and it increases with the increase of coarse particle content. The directional velocity ratio is defined. The initial value of horizontal infiltration rate is larger than that of vertical one, and then the vertical infiltration rate is gradually close to the horizontal value. The empirical relationship between the characteristic particle size and the stable infiltration rate is established, which provides a theoretical basis for the prediction of the stable infiltration rate in in-situ leaching.     

脉冲电沉积镍-铜合金

采用脉冲电沉积技术在304不锈钢表面制备Ni-Cu合金镀层,镀液组成和工艺条件为:NiSO4ꞏ6H2O 200g/L,CuSO4ꞏ5H2O 10 g/L,十二烷基硫酸钠0.2 g/L,柠檬酸钠80 g/L,糖精0.2 g/L,pH 4.0,温度25°C,搅拌速率30 r/min,平均电流密度40~120 mA/cm2,脉冲频率0~100 Hz,占空比20%~90%,时间30 min。研究了平均电流密度、脉冲频率和占空比对Ni-Cu合金镀层的元素组成、表面形貌和显微硬度的影响,得到较优的工艺参数为:平均电流密度40 mA/cm2,脉冲频率50 Hz,占空比60%。该条件下所得Ni-Cu合金镀层由质量分数分别为56.53%和43.47%的Ni和Cu组成,呈“菜花”状形貌,结晶细致、均匀,显微硬度为614.4 HV。