Preparation of ultra fine nickel-copper bimetallic powder for BME-MLCC

The preparation of ultra fine nickel-copper bimetallic powder with two-stage chemical reduction method was investigated. Reductive sugar and hydrazine hydrate were employed as reducing agent in different reductive stage, respectively. Reaction of CuSO₄·5H₂O with reductive sugar at 70 °C gives cuprous oxide and copper particles, then as-prepared mixture and nickelous hydroxide were reduced by hydrazine hydrate, and nickel-copper powder having excellent dispersibility was prepared. Influences of nickel added on composition and dispersibility of powder were studied. TG/DTG/DTA of nickel-copper powder, which is stable in room temperature, were discussed with thermal analyzer. Relation of nickel content to oxidation temperature was investigated. Ni-Cu bimetallic powder particles have a fully coated structure when nickel content is up to 30%. As-prepared nickel-copper powder was applied in base metal electrode-multilayer ceramic capacitor (BME-MLCC). The end termination has high adhesion force, fairly good densification, low resistivity, excellent solderibility behavior and resistance behavior to soldering.     

“微纳机电系统”课程教学方法探讨

本文从"微纳机电系统"课程的内容特点与教学方式两个方面对其教法展开了探索性研究。在课程内容方面,我们讨论了物理模型理解在该课程中的作用,强调了点面结合,系统地介绍微纳加工工艺的重要性。在教学方式上,我们增加建模软件ANSYS上机练习,提高学生的动手能力;结合工程实际问题,系统地介绍某一经典器件。     

Fine‐Grained FSMD Power Gating Considering Power Overhead

As a fine‐grained power gating method for achieving greater power savings, our approach takes advantage of the finite state machine with a datapath (FSMD) characteristic which shows sequential idleness among subcircuits. In an FSMD‐based power gating, while only an active subcircuit is expected to be turned on, more subcircuits should be activated due to the power overhead. To reduce the number of missed opportunities for power savings, we deactivated some of the turned‐on subcircuits by slowing the FSMD down and predicting its behavior. Our microprocessor experiments showed that the power savings are close to the upper bound.     

化学镍金工艺中的镍足控制方法研究

PCB上的线路日趋精细,焊盘间距也在不断缩小。目前,PCB上的最小焊盘间距可以达到0.050 mm。而在这些小间距的焊盘上进行化学镍金处理后,镍足就会从焊盘边缘往外延伸,从而导致渗金短路。分析了镍足变化的主要影响因素,研究了铜箔毛面粗糙度,钯离子吸附和沉镍药水活性对镍足生长的不同作用,总结了减小镍足的若干措施。     

GC—MS分析柠檬不同品种果皮精油成分

以云南德宏地区栽培的不同柠檬品种为试材,利用气质联用技术（GC-MS）分析果皮精油挥发性成分种类及相对含量,比较不同品种挥发性成分差异。结果表明,费米耐劳、云柠1号、艾伦尤力克柠檬果皮精油中分别检测到23、20、27种挥发性成分,烯烃类、醇类、醛类、酯类和酮类是3个品种共有组分。烯烃类物质是主要组分,其中特征香气成分D-柠檬烯含量最高,β-蒎烯、γ-萜品烯次之。艾伦尤力克柠檬中挥发性物质的种类和含量均高于费米耐劳和云柠1号柠檬,主要特征香气成分含量也最高。     

以工程教育专业认证为导向的食品科学与工程专业课程体系研究与实践

以工程教育专业认证为导向,为培养面向区域经济发展的现代高素质应用型食品人才,从工程教育专业认证标准、概况、课程体系结构调整、整合优化理论教学内容和实践教学体系等方面介绍兰州理工大学食品科学与工程专业课程体系改革的思路和实践。     

多环境大豆种子维生素E含量遗传分析

利用高效液相色谱测定了三个地点的大豆品种合丰25与Bayfield及其衍生的144个重组自交系种子中的维生素E含量,运用主基因＋多基因混合遗传模型,对三个地点的大豆种子的维生素E进行了遗传分析。结果表明：在哈尔滨地区α-生育酚为2对主基因＋多基因遗传模型;γ-生育酚为1对主基因＋多基因遗传模型;δ-生育酚为2对主基因＋多基因遗传模型;在呼兰地区α-生育酚为3对主基因＋多基因遗传模型;γ-生育酚为2对主基因＋多基因遗传模型;δ-生育酚为2对主基因＋多基因遗传模型;在绥化地区α-生育酚为无主基因＋多基因遗传模型;γ-生育酚为3对主基因＋多基因遗传模型;δ-生育酚为2对主基因＋多基因遗传模型。     

阻燃FDY涤纶长丝的生产实践

文章介绍了阻燃FDY涤纶长丝的生产实践。     

精糖生产过程中的脱色研究

选用二种脱色剂和三种絮凝剂，结合气浮提纯分离技术，运用正交试验方法，对精糖生产过程糖汁的脱色进行了对比研究，以达到优化工艺参数和指标的目的。结果表明，选用TR型脱色剂和TALODURA型絮凝剂对脱色和降低混浊度效果最好，清汁脱色率可达到65．74％，混浊度降低率可达到72．05％。