问题 名词解释

切削热和切削温度

答案

参考答案:

在切削过程之中,切削层金属的变形及刀具的前面与切屑、后面与工件之间的摩擦所消耗的功,绝大多数转变成为切削热,切削热再由切屑、刀具、工件及周围介质传出;所谓切削温度是指切削区域表面的平均温度。

单项选择题 A3/A4型题
单项选择题

Information systems design is defined as those tasks that focus on the specification of a detailed computer-based solution. Typically, there are four systems design tasks for in-house development.

①The first task is to specify (1), which defines the technologies to be used by one, more, or all information systems in terms of their data, processes, interfaces, and network components. This task is accomplished by analyzing the data models and process models that are initially created during requirements analysis.

②The next systems design task is to develop the (2). The purpose of this task is to prepare technical design specifications for a database that will be adaptable to future requirements and expansion.

③Once the database prototype has been built, the systems designer can work closely with system users to develop input, output and dialogue specifications. The (3)ust be specified to ensure that the outputs are not lost, misrouted, misused, or incomplete.

④The fourth design task involves packaging all the specifications from the previous design tasks into a set of specifications that will guide the (4) activities during the following phases of the systems development methodology.

Finally, we should (5) and update the project plan accordingly. The key deliverable should include a detailed plan for the construction phase that should follow.

(5)是()

A. adjust the project schedule

B. reevaluate project feasibility

C. evaluate vendor proposals

D. select the best vendor proposal