diffusion

/dɪˈfjuːʒn/ (bre, ipa) · /dɪˈfjuːʒn/ (ame, ipa) · /di-ˈfyü-zhən/ (ame, mw)

diffusion — noun

1. the process by which something spreads from a central point to cover a larger ar

1.名詞B2
釋義

the process by which something spreads from a central point to cover a larger area or reach more people

例句

The diffusion of wireless internet in rural Kenya connected thousands of students to online courses.

diffusion + of + [technology] + across + [area]

Ayana wrote a report on the diffusion of electric cars among European taxi companies.

同義詞
  • spread

    Everyday, simpler word; usable in all contexts where diffusion fits

  • dissemination

    More formal, strongly associated with information or ideas rather than physical objects

  • dispersal

    Emphasizes scattering apart or breaking up rather than covering an area

反義詞
  • concentration

    Gathering of things into one place rather than spreading them outward

  • containment

    Deliberate effort to keep something within a limited area

文法句型

diffusion + of + noun phrase

用法筆記

Often appears in academic or formal writing with 'of' to specify what is spreading (e.g., diffusion of innovation, diffusion of information). In everyday conversation, 'spread' is more common.

常見錯誤

The diffusion of the smell of coffee woke me up.
The diffusion of coffee culture around the world began in the 15th century.
💡'diffusion' describes a general or gradual process, not a single immediate sensory event.

2. the natural process through which particles spread out within a fluid until they

2.名詞C1
釋義

the natural process through which particles spread out within a fluid until they are evenly mixed throughout the surrounding space

例句

Andrés showed how a red ink drop spreads through water by diffusion without stirring.

passive process: diffusion without stirring

Oxygen enters the human bloodstream through diffusion in the tiny air sacs of the lungs.

同義詞
  • osmosis

    A specific type of diffusion where molecules pass through a semipermeable membrane

  • dispersion

    Focuses on particles spreading apart rather than the underlying molecular movement

文法句型

diffusion + of + noun phrase

diffusion + through + noun phrase

rate of diffusion

用法筆記

Frequently modified by technical adjectives such as 'molecular', 'gaseous', or 'thermal' in scientific writing. Describes a passive process driven by random molecular motion, not by an external force like stirring or blowing.

常見錯誤

Diffusion happens when you stir sugar into tea.
Diffusion happens when sugar molecules spread through water on their own without stirring.
💡stirring creates convection, not diffusion.

3. the scattering of light rays in multiple directions after they strike a rough su

3.名詞C1
釋義

the scattering of light rays in multiple directions after they strike a rough surface or pass through a material that is not completely clear

例句

Sunlight diffusion through the morning fog created a soft golden glow over the harbour.

diffusion + of + sunlight + through + [material]

Photographers use a softbox to create even light diffusion and soften harsh shadows on faces.

同義詞
  • scattering

    More general term; diffusion is a specific type of scattering that produces a soft, even spread

  • dispersion

    In optics, dispersion usually refers to splitting light into colours, not spreading it softly

反義詞
  • focus

    Concentrating light into a narrow beam rather than spreading it out

  • concentration

    Gathering light rays together at a single point

文法句型

diffusion + of + light/sunlight

light diffusion + through/by + material

用法筆記

Commonly paired with the preposition 'of' followed by 'light' or 'sunlight'. The material causing the scattering is typically introduced by 'through' (for translucent objects) or 'by' (for rough surfaces). Distinguish from sense 2, which describes particle movement rather than light behaviour.

常見錯誤

A mirror creates diffusion of light.
A frosted window creates diffusion of light.
💡mirrors reflect light directly without scattering it; diffusion requires a rough or translucent surface.

4. the way that customs, ideas, and technologies travel from one culture or communi

4.名詞B2
釋義

the way that customs, ideas, and technologies travel from one culture or community to another when people interact

例句

The diffusion of Buddhist teachings from India to East Asia profoundly changed art and philosophy.

diffusion + of + [religion/philosophy] + from + [origin] + to + [region]

Hui's master's thesis examined the diffusion of sushi culture from Japan to cities across Europe.

同義詞
  • transmission

    Often implies passing on within a tradition or across generations, not necessarily between distinct cultures

  • assimilation

    A deeper process where the borrowed element is absorbed and adapted, not just spread

反義詞
  • isolation

    Keeping cultures separate with minimal exchange of ideas or practices

文法句型

diffusion + of + [cultural feature]

cultural diffusion + among/across + [group/region]

用法筆記

Subject of diffusion is usually an abstract concept (religion, custom, technique, idea) rather than a physical object. Distinguish from sense 1 by the focus on cultural or social phenomena as opposed to physical or informational spread of any kind.

常見錯誤

The diffusion of smartphones happened very quickly.
The diffusion of smartphone etiquette norms took years to develop.
💡cultural diffusion describes the spread of ideas and behaviours, not the adoption of physical products.