density
density — 名詞
1. a measurement that compares how many people, animals, or objects are present in
密集度
單位空間內的人數或物件數量
a measurement that compares how many people, animals, or objects are present in an area with the physical size of that area
Taipei has a much higher population density than most cities in eastern Taiwan.
臺北的人口密集度比臺灣東部大部分城市高很多。
population density — countable units per area
The housing density in this neighbourhood is low, with large yards between each house.
這個社區的住宅密集度很低，每棟房子之間都有寬闊的庭院。
Amihan studied the density of wild deer across different forest regions for her biology report.
Amihan 為了她的生物報告，研究了不同森林區域的野鹿密集度。
In Eri's city, the density of bus stops varies widely from one district to another.
在 Eri 居住的城市裡，不同區域的公車站密集度差異很大。
Christopher checked the density of emergency exits in the building before his safety presentation.
Christopher 在做安全簡報前，先檢查了大樓內緊急出口的密集度。
- concentration
focuses on how much of something gathers in one spot; often used for resources or chemicals rather than populations
- compactness
emphasises how tightly things are packed together; less formal and rarely used for scientific measurements
- sparseness
describes an area with few people or objects spread far apart
用法筆記
Commonly combined with a noun describing what is being counted: population density, housing density, traffic density. The result is usually expressed as a number per square kilometre or per hectare.
常見錯誤
2. a scientific measurement of how much mass a material contains within a fixed amo
密度
物質質量與體積的比值
a scientific measurement of how much mass a material contains within a fixed amount of space, usually expressed as grams per cubic centimetre or kilograms per cubic metre
The density of water is about one gram per cubic centimetre at room temperature.
在室溫下，水的密度約為每立方公分一公克。
density of [substance] + measurement value
Gold's high density means a small bar can weigh several kilograms.
黃金的密度很高，一小塊金條就可能重達好幾公斤。
Elena compared the density of cooking oil with that of water for her science fair project.
Elena 為了她的科展作品，比較了食用油和水的密度。
Mathieu calculated the density of a small rock by weighing it and checking its volume in water.
Mathieu 透過秤重和測量水中的體積，計算出一塊小石頭的密度。
The density of aluminium is about one-third that of steel, so aircraft use aluminium parts.
鋁的密度大約是鋼的三分之一，所以飛機使用鋁製零件。
- specific gravity
compares a material's density to the density of water; used in older textbooks and some industries
- mass per unit volume
the full technical phrase; more precise but rarely used outside formal definitions
- buoyancy
not a true opposite; a less dense material floats in a denser one
用法筆記
In science classes, density is calculated using the formula density = mass ÷ volume. The standard SI unit is kg/m³, but g/cm³ is also common. Never use 'density' to mean simply 'heaviness' — a small piece of lead is heavy because of its high density, not because it has a lot of material overall.
常見錯誤
3. how packed, thick, or closely filled something is — for instance, the thickness
稠密
緊密或濃厚的程度
how packed, thick, or closely filled something is — for instance, the thickness of fog, the closeness of trees in a forest, or how many ideas fit into a short piece of writing
The density of the morning fog meant the airport had to delay all flights.
清晨的霧氣十分稠密，機場不得不延後所有航班。
density of fog — natural phenomenon
Shirin noticed the density of the bamboo forest — she could barely see the sky.
Shirin 注意到竹林非常稠密——她幾乎看不到天空。
The textbook's information density made it hard to read more than a few pages.
這本教科書的資訊密度很高，讀個幾頁就讓人吃不消。
Valentina loved the density of the old fabric — it felt heavy and rich in her hands.
Valentina 很喜歡那塊舊布料的紮實感——拿在手裡又沈又厚實。
The density of the smoke made it hard for the firefighters to see inside the house.
濃煙的稠密程度讓消防員在屋內幾乎無法看清東西。
- thinness
describes something that is not dense — thin fog, thin hair, thin forest cover
用法筆記
Unlike senses 1 and 2, this sense does not involve a precise numerical measurement. It describes a subjective impression of how densely something is packed. Distinguish from sense 1 (PEOPLE PER AREA): sense 3 can apply to fog, hair, vegetation, or writing — anything that can be described as 'dense' as a quality, not just a count per unit of area.