Kaʻume mākenēki permeability o ka waiwai

Ka pilina ma waena o kaʻume mākenēki kahua (H) a me kaʻume mākenēki koko nuʻa (B) i loko o ka mea ua wehewehe aku ma ka physical nui i kapaia oʻume mākenēki permeability. loaʻume mākenēki permeability o ka meakino - ka lākiō o ka B i H. E like me ka System o Units International ua anaia mai ka manawa i loko o huahelu i kapa 1 Henry no mika.

A laulā waiwai i hoike ia e ka lākiō o kona nui a hiki i ka nui o konaʻume mākenēki permeability o ka holo a me ka ua denoted e μ. Keia waiwai ua kapaia ka piliʻume mākenēki permeability (ole permeability) o ka meakino. Pehea ka pili ana, ka mea,ʻaʻohe huahelu.

No laila, ka hoahanauʻume mākenēki permeability μ - waiwai e hoike ana i na manawa he nui i loko o ka hoʻokomo kahua o ka meakino mea emi (a oi) o ka holo hoʻokomoʻume mākenēki kahua.

I ka wa olohelohe ia lakou i ka waiwai, e lilo ia magnetized ma ka mawahoʻume mākenēki kahua. Pehea ke ano o keia hana? E like me ke kuhiakau o Ampere, ma na mea ana i mau ai hoʻolahaʻia microscopic pou paialewa, kena ae la ma ka neʻeʻana o nā electrons i loko o kā lākou mau orbits a me ke alo o ko lākou mau ʻume mākenēki koke. Ma lalo o maʻamau rula, i kēia neʻeʻana i kāna hana, a me ke kahua "pio" (ana) kekahi i kekahi. I ka waiho i ke kino i loko o ka mawaho kula na paialewa hoonoho papa, a me ke kino i magnetized (m. E. Ua loaa iaʻu kona kahua).

a pau 'ona ka permeability mea okoa. Ma muli o ke kumukuai o ia mea, kumuhana mea mahele i loko o nui pūʻulu ekolu.

Ma diamagnetic waiwai oʻume mākenēki permeability μ - he uuku emi mai ma mua o kekahi. No ka laʻana, bismuth μ = 0,9998. By diamagnetic i kiniki, kēpau, pōaka, pohaku paakai, keleawe, aniani, hydrogen, benzene, wai.

Kaʻume mākenēki permeability o paramagnetic iki nui huahelu (no ka μ = 1,000023 Aluminum). Ano he kumu hoʻohālike o ka paramagnetic - nikala, oxygen, tungsten, ebonite, platinum, naikokene, ea.

Eia hoi, i ke kolu o ka pūʻulu e pili ana i ka helu o ka waiwai (ʻano nui i eliiaʻi a me ka oka a), konaʻume mākenēki permeability mea me ka nui loa (ma kekahi mau kauoha o ka nui) aku i ke kuʻikahi. Mau waiwai - ferromagnets. Holo nōhieʻaneʻi nā nikala, hao, cobalt a me kā lākou mau oka a pau. No ka kila μ = 8 ∙ 10 ^ 3 No ka mea nikala-hao oka a μ = 2,5 ∙ 10 ^ 5. Ferromagnetic lilo ka waiwai i maopopo ia mai nā 'ona. Mua, ka mea, i ke koena magnetism. Ka lua, kā lākou permeability mea he hana o ka mawaho kahua hoʻokomo. Apana, no ka kela mea keia mea o ia ma laila mea i kekahi paepae ana wela, i kapaʻia ka Curieʻoi ma i ka mea haalele i kona ferromagnetic waiwai, a lilo paramagnetic. No ka nikala Curie wahi - 360 ° C, no ka hao - 770 ° C.

Nā waiwai o ferromagnets hoʻoholo ole wale permeability akā, i ka nui aʻu, haawiia keia i like me ka magnetization o ka waiwai. Kēia mea he luna 'nonlinear hana oʻume mākenēki hoʻokomo, ua ho'ākāka' ia ma ulu magnetization laina kapa magnetization hālawa. Pela, ua hiki i kekahi wahi, i ka magnetization kokoke ekolu pohaku, e hoomahuahua i (ʻume mākenēki saturation ia lŘlŘ). Backlog waiwai ferromagnetic magnetization, mai ka ulu nui o ka mawahoʻume mākenēki kahua hoʻokomo ua kapaia hysteresis. Ma keia hihia, he mea he kaukaʻi o ka ferromagnet o kaʻume mākenēki ano ole wale nō ma luna o kona noho ana ma ka manawa, akā, no hoi ma kona mua magnetization. Mea kiʻi e hoohalike ai i keia papa hālawa ua kapaia hysteresis loop.

Manawa i kona waiwai, ferromagnetic mea olelo ia i loko o ke akamai. Ka mea, i hoʻohana 'ia i loko o rotors o Hawaii a me nā mīkini uila, ma o ka hana o ka mea hoʻololi uila Kora naʻEsau, a electromagnetic a kuapo kanaka, ma o ka hana o ka' ikamu o ka uila kamepiula 'ē aʻe. Kaʻume mākenēki waiwai o ferromagnetic mea i hoʻohana ma ka lipine recorders, helu kelepona, leki a me nā pūnaewele Media,.