Peb paub dab tsi txog selenium? Hauv tsev kawm ntawv chemistry zaj lus qhia, peb tau hais tias selenium yog cov khoom siv tshuaj lom neeg, peb tuaj yeem daws tau ntau yam kev sib npaug ntawm cov tshuaj thiab soj ntsuam cov tshuaj tiv thaiv nrog nws kev koom tes. Tab sis muaj ntau lub ntsiab lus nyob rau hauv lub sij hawm uas nws yog tsis yooj yim sua kom npog tag nrho cov ntaub ntawv. Yog li ntawd, txhua yam tau hais luv luv.
Hauv kab lus no, koj tuaj yeem paub txog lub ntsiab lus hu ua "selenium" kom ntxaws. Nws yog dab tsi, nws cov khoom yog dab tsi, qhov twg hauv qhov xwm txheej no tuaj yeem pom thiab nws siv li cas hauv kev lag luam. Tsis tas li ntawd, nws tseem ceeb heev kom paub tias nws muaj txiaj ntsig zoo rau peb lub cev.
Selenium yog dab tsi
Selenium (element Selenium) yog cov khoom siv tshuaj, ib qho analogue ntawm leej faj, uas yog nyob rau hauv pawg 16 (raws li kev faib ua ntej - mus rau 6th) ntawm lub sij hawm. Tus naj npawb atomic ntawm lub ntsiab yog 34, thiab atomic loj yog 78.96. Lub caij nthuav tawm feem ntau cov khoom tsis yog xim hlau. Nyob rau hauv cov xwm, selenium yog ib tug complex ntawm rau isotopes uas feem ntau nrog leej faj. Ntawd yog, nws pom nyob rau hauv qhov chaw uas leej faj yog mined. Yog li, lub mysterious selenium -nws yog dab tsi thiab vim li cas nws thiaj li muaj nqis? Nws muaj ntau yam khoom muaj txiaj ntsig.
keeb kwm ntawm kev tshawb pom ntawm selenium
Cov tshuaj no tau tshawb pom los ntawm Swedish chemist thiab mineralogist Jöns Jakob Berzelius hauv 1817.
Nyob rau hauv cov ntaub ntawv scientific muaj ib zaj dab neeg txog kev nrhiav pom pob zeb, qhia los ntawm tus kws tshawb fawb nws tus kheej.
Nws hais tias lub sijhawm ntawd nws, nrog rau lwm tus kws tshawb fawb hu ua Johan Gottlieb Gan (uas tau los ua nto moo raws li tus neeg nrhiav pom manganese thiab kawm txog nws cov khoom), tab tom tshawb nrhiav ib txoj hauv kev tsim cov sulfuric acid hauv nroog Gripsholm.
Nyob rau hauv chav kuaj sim hauv sulfuric acid, liab precipitates tau pom nrog ib tug admixture ntawm lub teeb xim av xim ntawm cov khoom. Thaum cuam tshuam nrog lub tshuab raj, lub teeb, tsis tshua muaj ntxhiab tsw emanated los ntawm cov ntaub ntawv sedimentary thiab cov hlaws txhuas tau tsim. Berlin tus kws tshawb fawb Martin Klaproth tau sib cav hais tias qhov muaj tus yam ntxwv tsw qhia tias muaj tellurium. Ib tug npoj yaig ntawm Berzelius kuj tau sau tseg tias hauv cov mines qhov twg cov sulfur no rau cov kua qaub mined (hauv Falun), cov ntxhiab tsw zoo sib xws kuj hnov.
Cia siab tias yuav pom qhov tsis tshua muaj, tsis ntev los no pom cov hlau (tellurium) hauv kev daws, cov kws tshawb fawb tau pib kawm cov av kom meej ntxiv, tab sis tsis muaj txiaj ntsig. Tom qab Berzelius sau tag nrho cov khoom uas tau sau ntau lub hlis ntawm kev tau txais sulfuric acid los ntawm kev hlawv cov sulfur, thiab kuj pib tshawb nrhiav.
Kev Tshawb Fawb tau pom tias qhov tshiab, yav dhau los tsis paub keeb kwm muaj cov khoom zoo sib xws rau tellurium, tab sis tsis yog. Yog li ntawd, lub periodic table tau txais ib lub caij tshiab- selenium.
Keeb kwm ntawm lub npe
Zaj dab neeg ntawm lub hauv paus ntawm lub npe ntawm lub caij tshiab yog nthuav heev. Lub sij hawm lub sij hawm ntawm Mendeleev txhais lub caij tshiab li Selenium (Se). Nws tau txais nws lub npe los ntawm lub npe ntawm peb lub ntuj satellite.
Thaum pib, hauv kev tshaj tawm Lavxias, lub ntsiab lus hu ua "selenium" (hauv kaum xyoo ntawm XIX caug xyoo). Tom qab ntawd, tom qab xyoo 1835, lub npe "selenium" raug saws.
YProperties ntawm selenium
Selenium formula – Se. Lub melting point ntawm cov khoom yog 217 (α-Se) thiab 170-180 degrees Celsius (β-Se), thiab nws boils ntawm ib tug kub ntawm 6850.
Cov oxidation hais tias selenium nthuav tawm hauv cov tshuaj tiv thaiv: (-2), (+2), (+4), (+6), nws tiv taus huab cua, oxygen, dej, hydrochloric acid thiab dilute sulfuric acid.
Dissolves nyob rau hauv siab concentration nitric acid, aqua regia, dissolves ntev nyob rau hauv alkaline ib puag ncig nrog oxidation.
Zoo ntawm selenium
Muaj ob qhov kev hloov kho ntawm selenium:
- Crystalline (monoclinic selenium a- thiab b-forms, hexagonal selenium g-forms).
- Amorphous (powdery, colloidal thiab glassy daim ntawv ntawm selenium).
Hloov kho ntawm amorphous liab selenium. Nws yog dab tsi? Ib qho kev hloov kho tsis ruaj khov. Hmoov thiab colloidal cov ntaub ntawv ntawm selenium yog tau los ntawm kev txo cov tshuaj los ntawm ib tug daws ntawm selenious acid H2SeO3.
Black vitreous selenium tuaj yeem tau txais los ntawm cua sov lub caij ntawm kev hloov kho rau qhov kub thiab txias220 degrees Celsius nrog ceev ceev.
Hexagonal selenium muaj xim grey. Qhov kev hloov kho no, qhov ruaj khov tshaj plaws thermodynamically, kuj tuaj yeem tau txais los ntawm cua sov mus rau lub melting point nrog rau qhov txias ntxiv rau qhov kub ntawm 180-210 degrees Celsius. Nws yog ib qho tsim nyog los tiv thaiv qhov kub thiab txias rau qee lub sijhawm.
YSelenium oxide
Muaj ntau cov oxides uas tsim los ntawm kev sib cuam tshuam ntawm selenium thiab oxygen: SeO2, SeO3, SeO, Se 2O5. Tib lub sijhawm, SeO2 thiab SeO3 yog selenium anhydrides (H2SeO 3) thiab selenic (H2SeO4) acids, uas tsim selenite thiab selenate ntsev. SeO2 (zoo soluble hauv dej) thiab ruaj khov tshaj plaws.
Kev sim txaus siab ntawm selenium
Ua ntej pib kev sim nrog cov khoom no, nws tsim nyog nco ntsoov tias txhua qhov sib xyaw nrog selenium yog tshuaj lom, yog li nws yuav tsum tau ua txhua yam kev ntsuas kev nyab xeeb, piv txwv li, hnav cov khoom tiv thaiv thiab ua cov tshuaj tiv thaiv hauv lub hood.
Cov xim ntawm selenium tshwm hauv cov tshuaj tiv thaiv zoo. Yog hais tias sulfur dioxide, uas yog ib tug zoo txo tus neeg sawv cev, yog dhau los ntawm ib lub raj mis nrog selenous acid, lub resulting tov yuav tig daj, ces txiv kab ntxwv, thiab thaum kawg ntshav liab.
Cov tshuaj tsis muaj zog yuav ua rau kom tau txais amorphous colloidal selenium. Yog hais tias qhov concentration ntawm selenous acid yog siab, ces thaum lub sij hawm cov tshuaj tiv thaiv, ib tug liab mus rau maroon hmoov yuav precipitate. Qhov no yuavamorphous hmoov selenium elemental daim ntawv.
Yuav kom coj cov khoom mus rau hauv lub khob iav, nws yuav tsum tau ua kom sov thiab txias kom nrawm. Cov xim yuav hloov mus rau xim dub, tab sis xim liab tsuas pom tau yog tias koj saib lub teeb.
Crystalline monoclinic selenium yuav nyuaj me ntsis kom tau txais. Ua li no, noj me me ntawm cov hmoov liab thiab sib tov nrog carbon disulfide. Nws yog ib qho tsim nyog los txuas lub reflux condenser rau lub nkoj nrog sib tov thiab boil rau 2 teev. Tsis ntev, cov kua txiv kab ntxwv lub teeb nrog me ntsis ntsuab tint yuav pib tsim, uas yuav tsum tau maj mam evaporated nyob rau hauv ib lub thawv nyob rau hauv lim ntawv.
Y
Siv selenium
Selenium yog thawj zaug siv hauv ceramic thiab iav kev lag luam. Nov yog qhov "Phau Ntawv Ntawm Cov Hlau Tsis Muaj" ntawm 1965 tsab qhia peb txog.
Selenium ntxiv rau lub khob loj kom tsis meej lub khob, kom tshem tawm cov lus qhia ntsuab ntsuab, uas muab ib qho admixture ntawm hlau sib txuas. Yuav kom tau txais cov iav ruby hauv kev lag luam iav, ib qho kev sib xyaw ntawm selenium thiab cadmium (cadmoselite CdSe) yog siv. Hauv kev tsim cov ceramics, cadmoselite muab nws cov xim liab thiab kuj stains enamels.
Ib me ntsis selenium yog siv los ua cov khoom siv hauv kev lag luam roj hmab thiab tseem nyob hauv kev lag luam steel los ua kom cov alloys ua tau zoo-grained.
Feem ntau cov tshuab semiconductor yog tsim los ntawm selenium. Qhov no yog qhov laj thawj tseem ceeb rau kev nce nqi ntawm cov khoom no,zoo li selenium. Tus nqi nce ntawm $ 3.3 mus rau $ 33 ib kilo hauv xyoo 1930 thiab 1956 raws.
Tus nqi selenium ntawm lub khw hauv ntiaj teb xyoo 2015 yog $ 68 ib 1 kg. Thaum xyoo 2012 ib phaus ntawm cov hlau no raug nqi txog $ 130 toj ib kg. Kev thov rau selenium (tus nqi lees paub qhov no) poob vim yog cov khoom siv siab.
Cov tshuaj no kuj tau siv dav hauv kev tsim cov khoom siv yees duab.
Kev muaj selenium hauv tib neeg lub cev
Peb lub cev muaj kwv yees li 10-14 milligrams ntawm cov khoom no, uas yog tsom mus rau ntau dua hauv cov kabmob xws li daim siab, ob lub raum, lub plawv, spleen, testicles thiab spermatic cords ntawm cov txiv neej, nrog rau cov nuclei. ntawm hlwb.
Kev xav tau ntawm tib neeg lub cev rau cov kab mob xws li selenium tsawg. Tsuas yog 55-70 micrograms rau cov neeg laus. Qhov siab tshaj plaws noj txhua hnub yog suav tias yog 400 micrograms. Txawm li cas los xij, muaj ib tus kab mob hu ua Keshan kab mob uas tshwm sim thaum lub caij no tsis txaus. Txog rau thaum xyoo 60s, selenium tau suav tias yog cov tshuaj lom neeg uas muaj kev cuam tshuam tsis zoo rau tib neeg lub cev. Tab sis tom qab kev tshawb fawb ntxaws, cov lus xaus tsis sib xws tau kos.
Ntau zaus, thaum kuaj pom cov ntsiab lus ntawm cov selenium, cov kws kho mob tuaj yeem sau tshuaj tshwj xeeb uas muaj kev sib xyaw ntawm zinc-selenium-magnesium, cov tshuaj uas, ua ke, yuav ua rau nws qhov tsis txaus hauv lub cev. Tau kawg, tsis suav nrog cov khoom noj uas muaj selenium.
Nyob zoo rau lub cev
Selenium plays lub luag haujlwm tseem ceeb hauv cov txheej txheemLub luag haujlwm tseem ceeb ntawm lub cev:
- nws qhib lub cev tiv thaiv kab mob - "stimulates" leukocytes kom muaj kev cuam tshuam ntau dua rau cov kab mob tsis zoo (cov kab mob);
- slows down the aging process in the body;
- txo txoj kev pheej hmoo ntawm arrhythmia, sudden coronary tuag los yog anoxia los ntawm qeeb cov roj cholesterol oxidation;
- ua kom cov ntshav ntws mus rau lub hlwb, ua kom lub hlwb ua haujlwm, txo cov tsos mob ntawm kev nyuaj siab thiab kev nyuaj siab (kev qaug zog, qaug zog, kev nyuaj siab thiab tsis xis nyob);
- slows down txoj kev loj hlob ntawm cov qog nqaij hlav cancer nrog antioxidant zog;
- nquag selenium tiv thaiv dawb radicals;
- thaum cuam tshuam nrog vitamin E ua raws li tus neeg sawv cev tiv thaiv kab mob.
Tau kawg, ib tus tsis tuaj yeem tsis quav ntsej txog cov cuab yeej tseem ceeb ntawm cov kab ke raws li kev pab cuam hauv kev tawm tsam cov kab mob txaus ntshai: HIV / AIDS, kab mob siab, Ebola.
Vim muaj cov selenium, tus kab mob nyob hauv lub cell; tshuaj tiv thaiv kev kis tus kab mob thoob plaws hauv lub cev. Tab sis yog tias tsis muaj selenium txaus, ces nws txoj haujlwm tsis ua haujlwm zoo.
Kev noj cov selenium ua ke nrog iodine yuav pab kom tsis txhob muaj cov thyroid kab mob (thyroxine deficiency), thiab qee zaum ua rau muaj tus kab mob regression (feem ntau hauv cov menyuam yaus).
Kuj nyob rau hauv cov tshuaj, selenium yog siv los tiv thaiv ntshav qab zib, raws li nws accelerates noj qabzib los ntawm lub cev.
Cov tshuaj uas muaj cov vitamins tuaj yeem sau rau cov poj niam cev xeeb tub. Nws pab tiv nrog cov tsos mob ntawm toxicosis, txo qaug zog thiabyuav txhawb koj zog.
Selenium deficiency
Vim li cas thiaj tsis muaj cov khoom xws li selenium hauv lub cev? Nws yog dab tsi - "tsis muaj selenium" thiab yuav ua li cas nrog nws? Qhov tseeb, qhov no yog kab mob tsis kaj siab, txawm tias nws tshwm sim tsis tshua muaj.
Nws yog ib qho tseem ceeb kom paub tias tus yeeb ncuab phem tshaj ntawm cov tshuaj no yog, ntawm chav kawm, carbohydrates - starchy, qab zib. Ua ke nrog lawv, selenium tsis zoo nqus los ntawm lub cev thiab qhov no yuav ua rau nws tsis txaus.
Dab tsi yog qhov cim ntawm kev tsis txaus? Ua ntej ntawm tag nrho cov, nws yuav tsum tau muab sau tseg tias nrog ib tug tsis muaj peev xwm ntawm selenium, efficiency thiab kev mus ob peb vas yuav txo.
Tsis muaj selenium ua rau lub cev tsis muaj zog, vim tias lub cev ua rau muaj ntau yam kab mob, ob lub hlwb thiab lub cev.
Tsis tas li, nrog qhov tsis txaus ntawm cov tshuaj no hauv lub cev, cov txheej txheem ntawm assimilation ntawm vitamin E cuam tshuam.
Cov cim tseem ceeb ntawm selenium deficiency yog: mob hauv cov leeg nqaij thiab pob qij txha, qaug zog ntxov ntxov, ntshav tsis txaus, kab mob ua rau lub raum thiab txiav txiav.
Tab sis yog tias koj hnov cov tsos mob, tsis muaj teeb meem koj yuav tsum tau noj tshuaj rau tus kheej. Nco ntsoov mus ntsib kws kho mob thiab sab laj txog qhov yuav tsum tau noj qee yam tshuaj. Txwv tsis pub, koj tuaj yeem ua rau nws tus kheej ua rau ntau dhau ntawm selenium, uas yog qhov phem dua hauv qee kis. Piv txwv li, yog tias tus neeg mob qog noj ntshav noj selenium tsis tuaj yeem tswj tau, chemo (chemotherapy) yuav tsis ua haujlwm.
Ntau selenium
Saturation nrog selenium kuj muaj qhov tsis zoo rau lub cev. Cov cim tseem ceeb ntawm cov khoom seem yog: kev puas tsuaj rau cov plaub hau thiab cov rau tes, kev puas tsuaj rau cov hniav, qaug zog thiab kev puas tsuaj mus tas li, tsis qab los noj mov, qhov tsos ntawm dermatitis, mob caj dab, nrog rau yellowness thiab tev ntawm daim tawv nqaij.
Tab sis yog tias koj tsis ua haujlwm ntawm cov chaw mining selenium, lossis tsis nyob ze cov chaw uas cov tshuaj no mined, ces koj tsis tuaj yeem ntshai cov selenium ntau dhau hauv lub cev.
Khoom noj muaj selenium
Feem ntau ntawm tag nrho cov selenium muaj nyob hauv cov nqaij thiab daim siab - nqaij npuas, nqaij nyuj, nqaij qaib, os lossis qaib ntxhw daim siab. Piv txwv li, 100 grams ntawm qaib ntxhw daim siab muaj 71, thiab nqaij npuas - 53 micrograms ntawm selenium.
100 grams ntawm octopus nqaij muaj 44.8 micrograms ntawm selenium. Tsis tas li ntawd, cov khoom noj yuav tsum muaj xws li cov cw, ntses liab, qe, pob kws, mov, taum, barley groats thiab lentils, nplej, peas, broccoli, inactive baker's poov xab (kho nrog dej rhuab mus rau 60 degrees). Tsis txhob hnov qab txog txiv ntoo - pistachios, almonds, walnuts thiab txiv laum huab xeeb kuj muaj selenium, txawm tias me me.
Nws tseem tsim nyog nco ntsoov tias cov khoom ploj thaum lub sijhawm ua zaub mov, cov zaub mov hauv kaus poom thiab cov concentrates muaj ib nrab ntawm selenium ntau npaum li cov zaub mov tshiab. Yog li ntawd, thaum twg los tau, nws yog ib qho tsim nyog yuav tsum tau noj ntau cov zaub mov tshiab nrog selenium li sai tau.
