问题 问答题 简答题

灯具的表面要做哪些处理?

答案

参考答案:

灯具的表面处理的主要目的是美观、保护原材料和提高反射面的反射系统系数等。灯具常用的表面处理方法有镀膜、涂漆、搪瓷、铝的阳极氧化薄膜处理、电解抛光和真空镀膜等几种。镀膜主要是电镀及融化锌热镀。涂漆又称为涂装,是金属本体,反射板等常用的表面处理方法。

照明器具的涂装主要工艺分为涂装前处理、涂料的涂装、涂膜的烘干。涂装一般是三聚氰胺的涂料的烧付涂装,三聚氰胺树脂的涂料,而候性好,反射率高(白色涂装的反射率为80%-90%)。在耐药品性、耐热性要求的场合,可以使用硅胶树脂涂料。粉体涂装是指金属加热,静电吸附使粉末涂装密着,再烧付干燥。其优点是涂膜较厚,耐药品性、耐水性较好。涂装后反射板的反射效率的高低与涂料的材质及工艺有关。普通高光粉末涂料的反射率一般在85%左右,高反射率粉末涂料的反射率能达到93%以上(涂膜厚度在65μm以上的),这将大大提高灯具的效率。铝的阳极氧化薄膜处理,是把铝作为阳极,放在电解液中进行电解,在铝的表面上即生成粘合性的、良好的钝态形的氧化薄膜。氧化薄膜的组成是氧化铝(AL2Oз)。

与未经阳极氧化处理的铝板比,它的硬度高,耐腐蚀性、耐磨性、可擦性能好,但当电解涂是硫酸、铬酸等时,氧化铝薄膜将局部溶解,而变成多孔质的一层,这就容易吸附多种物质,故有必要进行封孔处理。

阅读理解

It is common to believe that learning just takes place in school, but much of human learning happens outside the classroom, even from birth and people continue to learn throughout their lives.

Even before they enter school, young children learn to walk, to talk, and to use their hands to use toys, food, and other objects. They use all of their senses to learn about the sights, sounds, tastes, and smells in their environments. They learn how to communicate with their parents, grandparents, siblings, friends, and other people important to their world. When they enter school, children learn subjects like reading, writing, and maths. They also continue to learn a lot outside the classroom. They learn which behaviors are likely to be rewarded and which are likely to be punished. They learn social skills for communicating with other children. After they finish school, people must learn to deal with many changes that affect their lives, such as getting married, raising children, and finding and keeping a job.

Because learning continues throughout our lives and affects almost everything we do, the study of learning is important in many different fields. Teachers need to understand the best ways to educate children. Scientists, social workers and other human service workers need to understand how certain experiences change people’s behaviors.

Learning is closely related (相关的) to memory, which is the storage of information in the brain (大脑). Scientists who study memory are interested in how the brain stores knowledge, where this storage takes place, and how the brain later offers knowledge when we need it. However, scientists who study learning are more interested in behavior and how behavior changes as a result of a person’s experiences. 

小题1:The underlined word “siblings” in Paragraph 2 probably means _________.

A.teachers

B.classmates

C.doctors

D.brothers or sisters小题2: When do children begin to know to behave well according to the passage?

A.After they go into society.

B.Before they enter school.

C.When they are at school.

D.Before they are born.小题3:Which of the following is WRONG according to the passage?

A.As a matter of fact, learning begins at a person’s birth and last the whole life.

B.Teachers need to understand the best ways to educate their students.

C.People need to understand how certain experiences change their behaviors.

D.Social workers need to study how experiences affect people’s thoughts.

名词解释