Word · Frequency #23934
downcast
向下转换；向下转型
核心释义
编程术语
In computing, a cast that converts a value from a supertype to a subtype; a downcast.
- 1.
向下看的动作,通常表示沮丧、悲伤,有时表示谦逊；引申为沮丧、忧郁
An act of looking downwards, usually as a sign of discouragement, sadness, etc., or sometimes modesty; hence (uncountable, archaic), dejection, melancholy.
- 2.
进风井
a ventilation shaft through which air enters a mine
- 3.
(数据类型)从父类型到子类型的转换
A cast (“change of expression of a data type”) from supertype to subtype.
- 4.
矿井中空气下行通风的通风井
A ventilating shaft down which air passes in circulating through a mine.
进风井；通风井；低头；沮丧；忧郁；向下看的动作,通常表示沮丧、悲伤,有时表示谦逊；引申为沮丧、忧郁；进风井；(数据类型)从父类型到子类型的转换
用法In use
The miners entered the mine through the downcast to access the lower levels.
用法提示：这里 'downcast' 作为名词，指矿井的进风井，用于通风和人员进出。
Fresh air flows down the downcast, providing ventilation to the underground tunnels.
用法提示：句中 'downcast' 表示通风竖井，是矿井通风系统的重要组成部分。
The engineer inspected the downcast for any blockages that could reduce airflow.
用法提示：这里的 'downcast' 指矿井的进风通道，维护其畅通对安全至关重要。
with a downcast
作可数名词，指低头（常表示沮丧、悲伤或谦逊）的动作；常与 with 连用表示伴随状态。
She replied with a downcast, unwilling to meet my eyes.
她低着头回答，不愿与我对视。
a downcast from sth to sth
计算机术语，指数据类型从父类型到子类型的转换；常与 from ... to ... 连用。
相关词与表达Connections
搭配Collocations
- downcast shaft
- 进风井；下行通风井
- Fresh air travels down the downcast shaft into the mine.新鲜空气沿着进风井下行进入矿井。
- downcast of the eyes
- 低垂的目光
- The downcast of her eyes revealed her modesty.她低垂的目光流露出她的谦逊。
- explicit downcast
- 显式向下转换
- The compiler rejected the code because it required an explicit downcast.编译器拒绝了这段代码，因为它需要显式向下转换。
近义词Synonyms
学习提示Learner notes
记忆技巧Memory Tip
把“cast”（投射）想象成目光向下投：眼睛朝下看，自然显得沮丧或谦卑——记住“down（向下）+ cast（投射）”就是垂头丧气的样子。
语境与语域Context & Register
语域：mixed 常见场景：文学/正式写作、采矿工程、编程/软件开发 含义因语境而异：采矿工程中指“进风井”，编程中指“从父类型到子类型的向下转换”；而“低头/沮丧”的用法比较正式，多用于文学或书面语。
语法说明Grammar Note
该词作为可数名词，指矿井中的进风井。
发音与拼写Pronunciation & Spelling
All six words rhyme with the target's final syllable in American English: each ends in /ˌkæst/ (cast itself /kæst/). Watch out for the lookalike 'castle' /ˈkæsəl/, which is spelled with 'cast' but has a silent 't' and a different vowel; and be aware that in British English, the '-cast' ending is often pronounced /kɑːst/ rather than /kæst/.
一起学习词形Learn the forms together
页面下方列出了常见词形变化。学习时注意它们在句子中的语法位置。
Dictionary facts from ECDICT, WIKTIONARY.