粉(食物)的英文意思

Rice vermicelli 米粉
Rice vermicelli are thin noodles made from rice, sometimes also known as rice noodles or rice sticks. They are a part of several Asian cuisines, where they are often eaten as part of a soup dish, stir fry, or salad. Rice vermicelli are particularly prominent in the cuisines of China and Southeast Asia, many of which feature a notable Chinese culinary influence.
One particularly well known, slightly thicker variety, is called Guilin mǐfěn (桂林米粉), comes from the southern Chinese city of Guilin, where it is a breakfast staple. In Yunnan, such noodles are called mǐxiàn (米线).

Powder (麵粉)

A powder is a dry, bulk solid composed of a large number of very fine particles that may flow freely when shaken or tilted.

Powders are a special sub-class of granular materials, although the terms powder and granular are sometimes used to distinguish separate classes of material. In particular, powders refer to those granular materials that have the finer grain sizes, and that therefore have a greater tendency to form clumps when flowing.

Granulars refers to the coarser granular materials that do not tend to form clumps except when wet.

Types of Powders
Examples of powders would include ground coffee, powdered milk, cosmetic powders, gunpowder, powdered sugar, fine snow, household dust, volcanic ash, the top layer of the lunar regolith, copy machine toner, and many pharmaceuticals.

Because of their importance to industry, medicine and earth science, powders have been studied in great detail by chemical engineers, mechanical engineers, chemists, physicists, geologists, and researchers in other disciplines.


Powder Transport
Powders are transported in the atmosphere differently than a coarse granular material. For one thing, tiny particles have relatively little inertia compared to the drag force of the gas that surrounds them, and so they tend to go with the flow instead of traveling in straight lines. For this reason, powders may be an inhalation hazard.

Larger particles cannot weave through the body's defenses in the nose and sinus, but will strike and stick to the mucous membranes. The body then moves the mucous out of the body to expel the particles. The smaller particles on the other hand can travel all the way to the lungs from which they cannot be expelled.

Serious and sometimes fatal diseases such as silicosis are a result from working with certain powders without adequate respiratory protection.

Also, if powder particles are sufficiently small, they may become suspended in the atmosphere for a very long time. Random motion of the air molecules and turbulence provide upward forces that may counteract the downward force of gravity.

Coarse granulars, on the other hand, are so heavy that they fall immediately back to the ground.

For comparison, the Moon has neither wind nor water, and so its regolith has vast quantities of hazardous dust but no mudstone.

The cohesive forces between the particles tend to resist their becoming airborne, and the motion of wind across the surface is less likely to disturb a low-lying dust particle than a larger sand grain that protrudes higher into the wind. Mechanical agitation such as vehicle traffic, digging, or passing herds of animals is more effective than a steady wind at stirring up a powder.


Comparison with other substances
A paste or gel might become a powder after it has been thoroughly dried, but is not considered a powder when it is wet because it does not flow freely.

Substances like dried clay, although dry bulk solids composed of very fine particles, are not powders unless they are crushed because they have too much cohesion between the grains, and therefore they do not flow freely like a powder. A liquid flows differently than a powder, because a liquid cannot resist any shear stress and therefore it cannot reside at a tilted angle without flowing (that is, it has zero angle of repose.) A powder on the other hand is a solid, not a liquid, because it may support shear stresses and therefore may display an angle of repose.