工业纯铝在模拟海水中的电化学腐蚀行为

为研究铝在海水中的腐蚀过程,采用电化学阻抗谱、浸泡试验、扫描电子显微镜研究工业纯铝在模拟海水中的腐蚀行为.结果表明:铝在模拟海水中发生点蚀的区域为富含Fe的晶间化合物处,点蚀半径随时间的增加而扩大.铝在模拟海水中的溶解曲线分为4个区间:活性溶解区、过渡区、过钝化区、钝化区.铝在模拟海水中,极化电位为过钝化区时,转移电阻R t随着电位的升高而变小,铝发生严重的点蚀;而极化电位为钝化区时,铝的转移电阻R t随着电位的升高基本不变,铝的溶解行为受到抑制.工业纯铝在模拟海水中发生点蚀的电位区间是-0.45～-0.65 V,钝化电位区间为-0.75～-0.85 V.     

环境媒介与具身交互:艺术疗愈空间的热点与趋势

在人们情绪压力不断增大的当今社会,艺术疗愈以其创造性特征和非语言媒介帮助疗愈对象改善心理或身体状态,旨在讨论艺术疗愈空间中的环境媒介与疗愈过程中的具身交互关系、设计实践与价值。借助CiteSpace可视化软件分析近十年来的重要文献,揭示艺术疗愈的研究现状;运用文献计量学方法,探索环境媒介在艺术疗愈空间的应用,定义环境媒介的具身性、主体间性、沉浸性特征及三者间的关联;以具身交互理论为线索,结合设计案例分析疗愈空间中环境媒体的具身性实践与作用方式,以期进一步探索结合新兴技术的环境媒介未来在我国的应用发展。艺术疗愈空间的环境媒介能具身地影响疗愈对象的交互行为与认知,提高疗愈的效率和质量。环境媒介与具身交互能增进疗愈过程中的不同主体间的体验共享,并辅助疗愈对象沉浸地参与或融入艺术疗愈;数字技术的发展不断地丰富环境媒介的形式,提高艺术疗愈的效果。     

Single-Step Fast Tissue Clearing of Thick Mouse Brain Tissue for Multi-Dimensional High-Resolution Imaging

Recent advances in optical clearing techniques have dramatically improved deep tissue imaging by reducing the obscuring effects of light scattering and absorption. However, these optical clearing methods require specialized equipment or a lengthy undertaking with complex protocols that can lead to sample volume changes and distortion. In addition, the imaging of cleared tissues has limitations, such as fluorescence bleaching, harmful and foul-smelling solutions, and the difficulty of handling samples in high-viscosity refractive index (RI) matching solutions. To address the various limitations of thick tissue imaging, we developed an Aqueous high refractive Index matching and tissue Clearing solution for Imaging (termed AICI) with a one-step tissue clearing protocol that was easily made at a reasonable price in our own laboratory without any equipment. AICI can rapidly clear a 1 mm thick brain slice within 90 min with simultaneous RI matching, low viscosity, and a high refractive index (RI = 1.466), allowing the imaging of the sample without additional processing. We compared AICI with commercially available RI matching solutions, including optical clear agents (OCAs), for tissue clearing. The viscosity of AICI is closer to that of water compared with other RI matching solutions, and there was a less than 2.3% expansion in the tissue linear morphology during 24 h exposure to AICI. Moreover, AICI remained fluid over 30 days of air exposure, and the EGFP fluorescence signal was only reduced to ~65% after 10 days. AICI showed a limited clearing of brain tissue >3 mm thick. However, fine neuronal structures, such as dendritic spines and axonal boutons, could still be imaged in thick brain slices treated with AICI. Therefore, AICI is useful not only for the three-dimensional (3D) high-resolution identification of neuronal structures, but also for the examination of multiple structural imaging by neuronal distribution, projection, and gene expression in deep brain tissue. AICI is applicable beyond the imaging of fluorescent antibodies and dyes, and can clear a variety of tissue types, making it broadly useful to researchers for optical imaging applications.     

汽车起动用铅酸蓄电池化成半化率的讨论及研究

实验研究极板化成装板后浸泡时间对汽车起动用铅酸蓄电池化成半化率的影响。通过比较充电前浸泡时间分别为10 min、20 min、30 min、40 min、50 min、60 min后的极板半化率,得出结论极板浸泡30 min开始充电极板半化率最低。     

探测器光学系统反常区的像差特性及应用

分析浸没透镜、场镜单折射球面反常区及半反常区的像差特性,说明利用反常区和半反常区的像差对红外物镜像差的校正原理。     

Intermetallic formation in Sn3Ag0.5Cu and Sn3Ag0.5Cu0.06Ni0.01Ge solder BGA packages with immersion Ag surface finish

The intermetallic compounds formed in Sn3Ag0.5Cu and Sn3Ag0.5Cu0.06Ni0.01Ge solder BGA packages with Ag/Cu pads are investigated. After reflow, scallop-shaped η-Cu₆Sn₅ and continuous planar η-(cu_0.9Ni_0.1)₆Sn₅ intermetallics appear at the interfaces of the Sn3Ag0.5Cu and Sn3Ag0.5Cu0.06Ni0.01Ge solder joints, respectively. In the case of the Sn3Ag0.5Cu specimens, an additional ε-Cu₃Sn intermetallic layer is formed at the interface between the η-Cu₆Sn₅ and Cu pads after aging at 150°C, while the same type of intermetallic formation is inhibited in the Sn3Ag0.5Cu0.06Ni0.01Ge packages. In addition, the coarsening of Ag₃Sn precipitates also abates in the solder matrix of the Sn3Ag0.5Cu0.06Ni0.01Ge packages, which results in a slightly higher ball shear strength for the specimens.     

Interfacial reaction between 42Sn-58Bi solder and electroless Ni-P/immersion Au under bump metallurgy during aging

The interfacial reaction between 42Sn-58Bi solder (in wt.% unless specified otherwise) and electroless Ni-P/immersion Au was investigated before and after thermal aging, with a focus on the formation and growth of an intermetallic compound layer, consumption of under bump metallurgy (UBM), and bump shear strength. The immersion Au layer with thicknesses of 0 μm (bare Ni), 0.1 μm, and 1 μm was plated on a 5-μm-thick layer of electroless Ni-P (with 14–15 at.% P). The 42Sn-58Bi solder balls were then fabricated on three different UBM structures by using screen printing and pre-reflow. A Ni₃Sn₄ layer formed at the joint interface after the pre-reflow for all three UBM structures. On aging at 125°C, a quaternary phase, identified as Sn₇₇Ni₁₅Bi₆Au₂, was observed above the Ni₃Sn₄ layer in the UBM structures that contain Au. The thick Sn₇₇Ni₁₅Bi₆Au₂ layer degraded the integrity of the solder joint, and the shear strength of the solder bump was about 40% less than the nonaged joints.     

一种超粗化表面处理用于改善沉锡脱油的工艺探讨

沉锡工艺是一种代替传统热风整平的新型环保工艺,但沉锡工艺中的脱油问题一直是难以解决的问题,现通常方法是使用专用耐沉锡油墨或前处理使用超粗化药水处理板面,提高油墨和铜面的结合力,前两种方法的生产成本大大升高;本文根据现有的前处理方式,实验出适合沉锡使用的阻焊前处理方式,并列举该方式的具体应用。     

浸入式光栅谱线特性

浸入式光栅常应用于光学材料折射率较高的红外谱段.其特殊的工作模式会产生一系列普通反射式光栅不需面临的问题, 而它们对于浸入式光栅的应用却十分重要.论文推导了普通光栅长波端与短波端谱线长度的关系.针对折射率与波长相关的特点, 以短波红外(1.5~2.5 μm)为例, 分析其谱线位置分布及光谱分辨率变化特性.结果表明, 浸入式光栅谱线分布相较于普通光栅有明显差异, “梯形”谱线会发生倾斜.在折射率变化较大的短波红外谱段, “梯形”谱线倾斜程度较明显.在以长波(2.5 μm)配准Littrow条件时, 谱线向短波端倾斜, 以短波(1.5 μm)配准时向长波端倾斜, 且Littrow波长均漂离中心波长.由于折射率在热红外谱段变化较小, “梯形”谱线倾斜较小, 更接近普通光栅情况.浸入式光栅的光谱分辨率随折射率变化而改变, 同级中, 波长增大分辨率增大;各级间, 级数减小分辨率减小.同时, 由于高级次(短波)分辨率大于低级次(长波), 因此各级谱线长度之比不再满足普通光栅中的比例关系.