摘要：This paper presents the findings of an experimental investigation into the effects of cutting speed, feed rate, depth of cut and approach angle in turning of titanium (Grade 5) alloy. A two-level factorial experiment has been used to accomplish the objective of the experimental study. The main cutting force, i.e. tangential force (Fc) and surface roughness (Ra) were the response variables investigated. The experimental results indicate that the proposed mathematical models suggested could adequately describe the performance indicators within the limits of the factors that are being investigated. The feed, cutting speed and depth of cut is the most significant factor that influences the surface roughness and the tangential force. However, there are other factors that provide secondary contributions to the performance indicators.

摘要：The recent development of Cu-based electrocatalysts for electrochemical reduction of carbon dioxide（CO） has attracted much attention due to their unique activity and selectivity compared to other metal catalysts. Particularly, Cu is the unique electrocatalyst for COelectrochemical reduction with high selectivity to generate a variety of hydrocarbons. In this review, we mainly summarize the recent advances on the rational design of Cu nanostructures, the composition regulation of Cu-based alloys, and the exploitation of advanced supports for improving the catalytic activity and selectivity toward electrochemical reduction of CO. The special focus is to demonstrate how to enhance the activity and selectivity of Cubased electrocatalyst for COreduction. The perspectives and challenges for the development of Cu-based electrocatalysts are also addressed. We hope this review can provide timely and valuable insights into the design of advanced electrocatalytic materials for COelectrochemical reduction.

摘要：本文建立了一个关于马氏体相变温度和价电子数及电子浓度的经验图谱并设计了一系列ZrCu基形状记忆合金.这些相变温度包括了所有报道过的经Ni、Co、Hf、Ag、Ti、Al、Cr等掺杂替换Zr或者Cu原子的约40种合金.反映了转变温度和电子浓度或者电子密度之间的关系.结果显示ZrCu基合金的转变温度逐渐下降,当cv>0.218时,相变温度急剧下降.ZrCu基合金的马氏体相变温度与电子密度呈线性关系.基于相变温度和滞后图谱的结果可以设计出在不同条件下工作的ZrCu基合金.

摘要：本文建立了一个真实时空的相场模型模拟,研究了含不同尺寸和体积分数的球形第二相颗粒的纳米结构AZ31镁合金的晶粒生长过程;第二相颗粒对单相合金系统晶粒组织演化和生长动力学的影响;并将模拟结果与微米晶结构镁合金的模拟结果相比较.通过在自由能密度函数的表达式中增加第二相颗粒的表达来改进模型.模拟结果表明:纳米晶组织中第二相粒子对晶粒长大的钉扎作用,与对微米晶组织下的作用有很大区别.纳米结构中,第二相颗粒对晶粒长大影响存在一个粒子尺寸的临界值,当第二相颗粒体积分数为10%时,粒子尺寸的临界值为200 nm,随粒子含量增加,临界尺寸值将减小.另一方面,粒子含量越大对晶界钉扎作用越大,晶粒平均尺寸越小.该研究将为选择复合加入和原位合成的方法在AZ31镁合金中引入第二相颗粒的实验研究提供显微组织设计的理论指导.

摘要：A lloy是一种具有简洁语法结构的形式语言(form al language),它能够对众多不同类型的系统建模、规范并进行自动化分析。而作为半形式语言(sem i-form al language)的UML(Un ified Modelling Language),是一种用于对软件系统进行描述、可视化和构架,并用于商业建模的语言。它作为一种对基于对象的系统进行建模、规范和执行的事实上的标准,已经被软件工程界所广泛接受。利用这两种语言各自的优势,提出了设计继电保护离散动作行为的UML模型的思想,并以三段式电流保护为例进行分析与建模,最后对其转化为A lloy模型以及对转化后的模型实施各种分析进行了论述。

摘要：通过对TC21钛合金铣削正交试验,测量表面粗糙度,构建粗糙度预测公式。并以最大材料去除率及最小表面粗糙度为优化目标采用遗传算法对钛合金铣削切削参数进行优化,以期对生产实践起到一定的指导作用。

摘要：TC4钛合金的屈服强度和弹性模量比值高,故其成形后回弹量大,成形后不精确,难以成形出合格零件,需要进行校形,以得到合格零件。因此对钛合金进行了校形实验,得到了感应加热工艺参数对材料校形的影响规律。并运用大型商用模拟软件ANSYS建立了钛合金热应力校形的模型,利用软件中LS-DYNA求解器,对钛合金热应力校形的过程进行了模拟。从而找出钛合金环热应力校形中的一些规律和校形最佳参数,期望能够将其用于指导生产。

摘要：针对高超深井油管悬挂器设计计算及选材的问题,分别对油管悬挂器本体为75K 12Cr13和120K 718alloy的材料的连接强度和悬挂器本体的拉伸强度进行计算,以及油管自身承载能力的计算。结果表明:120K 718alloy油管悬挂器在同压力等级下具有更高的载荷能力,可以满足如高超深井等工况更苛刻的井口使用要求。