Effect of substrate pretreatment on the porosity in thin nickel electrodeposits

Substrate pretreatment affects the porosity of thin nickel electrolytic coatings which is a combined function of the composition and the roughness of the substrate surface. Electropolishing the substrate surface is an effective method of reducing coating porosity, whereas coatings plated on either electroetched or mechanically ground substrates are relatively porous owing to the remaining oxide layer on the substrate and the increased roughness of the substrate. For nickel coatings plated on mechanically ground rough substrates, the relationship between nickel porosity, apparent coating thickness and substrate roughness has been examined.     

Sr对高铁Al-Si合金组织和性能的影响

研究了Sr元素（加入量分别为0．03％、0．06％、0．09％、0．12％和0．18％）对含Fe量为1．2％的ZL102合金的组织和性能的影响。研究发现，随着Sr元素的加入，合金中粗大的针状Fe相开始出现断裂分叉现象，同时针状Fe相的长度也随Sr元素加入量的增加而减小，但Sr对Fe相的针状形貌没有明显改变。随着Sr元素加入量逐渐增加，合金的抗拉强度和伸长率均呈现出先增后减的变化趋势。当Sr元素加入量达到0．12％时，合金材料的综合力学性能最佳。     

BREAKAGE MECHANISM OF TUNGSTEN BASED ALLOY BLOCK FOR ELECTRO-HEAT UPSETTING

The breakage mechanism of W-Ni-Fe alloy in the process of electro-heat upsetting studied both theoretically and experimetnally, and also the behaviors of crack formation and propagation were analysed. Alloy suffers from corrosion and thermal-mechanical fatigue mutual function. Simultaneously, the practical ways to improve the anvil life was discussed.     

基于文本分析的自动化疾病编码方法

对疾病进行编码是将疾病诊断名称转化为标准ICD(国际疾病分类)编码的过程.鉴于编码量庞大和人工编码效率低等原因,有必要实现疾病编码的自动化.提出一种自动化的疾病编码方法,使用一种文本建模方法将ICD表示为文本集,然后借助文本相关性度量,获取与待编码疾病诊断名称最相关的ICD编码.经实验验证,本文提出的自动化疾病编码方法准确率较高、效率优秀、分类层次变换灵活,可广泛应用于各种类型的数据分析场景.     

浅谈信息技术与数学学科的整合

信息技术的发展,使人们的学习和交流打破了过去的时空界限,为人类能力的提高和发挥作用带来了新的空间。通过信息技术与数学学科的整合,让数学更贴近生活,突破教学重点难点,提高了学生的发散性思维能力,让我们看到信息技术在教学中的重要性。     

Laminated paper-based analytical devices (LPAD): fabrication, characterization, and assays

Paper-based microfluidic devices have recently garnered an increasing interest in the literature. The majority of these devices were produced by patterning hydrophobic zones in hydrophilic paper via photoresist or wax. Others were created by cutting paper using a laser. Here, we present a fabrication method for producing devices by simple craft-cutting and lamination, in a way similar to making an identification (ID) card. The method employs a digital craft cutter and roll laminator to produce laminated paper-based analytical devices (LPAD). Lamination with a plastic backing provides the mechanical strength for a paper device. The approach of using a craft cutter and laminator makes it possible to rapid-prototype LPAD with no more difficulty than producing a typical ID card, at very low cost. Devices constructed using this method have been exploited for simultaneous detection of bovine serum albumin (BSA) and glucose in synthetic urine with colorimetric assays. Both BSA and glucose are detectable at clinically relevant concentrations, with the detection limit at 2.5 μM for BSA and 0.5 mM for glucose.     

机械加工过程中的振动及控制方法研究

机械加工中的振动对于加工质量和生产效率都有很大影响,须采取措施控制振动.本文首先简要介绍了机械加工过程中的振动问题的危害,然后详细介绍了消除或减弱机械加工过程中的振动的具体方法和策略.