2024 Tus sau: Elizabeth Oswald | [email protected]. Kawg hloov kho: 2024-01-13 00:07
Pyridinium chlorochromate (PCC) yog ib qho tseem ceeb reagent nyob rau hauv cov organic synthesis siv feem ntau rau xaiv oxidation ntawm cawv kom muab carbonyl compounds.
Corey's reagent yog dab tsi siv rau?
Nws yog ib qho reagent hauv cov organic synthesis siv feem ntau rau oxidation ntawm cawv los ua carbonyls. Ntau yam sib txuas sib txuas tau paub nrog cov tshuaj zoo sib xws. PCC muab qhov zoo ntawm kev xaiv oxidation ntawm cawv rau aldehydes lossis ketones, qhov ntau lwm cov tshuaj reagents yog xaiv tsawg.
PCC yog dab tsi?
PCC yog tus neeg sawv cev oxidizing. Nws hloov cawv rau carbonyls, tab sis tsis muaj zog txaus los hloov cov cawv thawj rau hauv carboxylic acid. Nws tsuas yog hloov cov cawv thawj rau aldehydes, thiab cov cawv thib ob rau ketones. 1-pentanol yog thawj cawv yog li nws yuav hloov mus rau aldehyde pentanal.
PCC ua dab tsi rau lub diol?
PCC tsis yog-aqueous thiab tsis-acidic, tshem tawm cov xwm txheej raws li lub pov haum Diol yuav tsim. Yog li ntawd, qhov thib ob oxidation kauj ruam los ntawm ib qho aldehyde mus rau carboxylic acid yuav tsis tshwm sim.
Dab tsi yog qhov tsis zoo ntawm PCC?
PCC yog acidic dua PDC, tab sis cov kua qaub-labile tebchaw tuaj yeem oxidized nyob rau hauv muaj sodium acetate los yog lwm yam buffers xws li carbonates. Lwm qhov tsis zoo yog tsim cov khoom khov uas cuam tshuam cov khoom sib cais.
Pom zoo:
Cov khoom siv dab tsi yog siv rau phab ntsa screeding?
Plaster of Paris yog ib qho zoo tshaj plaws thiab feem ntau siv cov khoom siv screeding uas muab koj cov phab ntsa zoo tag thiab du. POP mix yuav tsum muaj ob qho khoom xyaw nrog rau cov hmoov gypsum tseem hu ua POP cement thiab tshwj xeeb POP Screeding Paint.
Puas yog cov dab dab dab dab dab dab dab dab dab dab dab dab?
Myth: Ib tug dab tshos tsis yog neeg ncaj ncees yog tiasnws haum yog. Fact: Tu siab, qhov no yog ib lo lus tsis tseeb uas tau raug perpetuated los ntawm aversive trainers. Txawm hais tias haum rau lub caj dab kom zoo khawb rau hauv cov tawv nqaij rhiab nyob ib ncig ntawm lub caj dab, uas ua rau muaj kev puas tsuaj loj rau cov thyroid, esophagus, thiab trachea.
Yuav ua li cas txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau pom kev pom?
Txawm li cas los xij, corneal collagen cross-linking - cov txheej txheem qib siab tau pom zoo los ntawm US Food and Drug Administration (FDA) hauv xyoo 2016 - tuaj yeem txhim kho qhov pom kev hauv cov neeg mob txhua hnub nyoog. Corneal collagen cross-linking (CXL) tsis yog kho rau keratoconus, tab sis nws tuaj yeem pab tiv thaiv tus mob kom tsis txhob mob hnyav.
Yuav siv dab tsi txhawm rau txhawm rau txhawm rau txhawm?
Siv phom caulk siv cov hlaws tuab ntawm caulk ncig ntawm ntug ntawm lub txee. Tsa lub dab dej kom nws nias tawm tsam lub hauv qab ntawm lub countertop thiab tsim cov dej tsis sib haum. Ntxiv cov laug cam thiab shims raws li xav tau los xyuas kom meej lub dab dej nyob hauv qhov chaw.
Puas yog cov dab dab dab dab dab dab tau them?
OHL cov neeg ua si tsis tau nyiaj hli, vim lawv tsis raug lees paub tias yog cov neeg ua haujlwm raws li Txoj Cai Kev Ua Haujlwm. Txawm li cas los xij, lawv suav nrog cov txiaj ntsig xws li nyiaj rov qab txhua xyoo, tag nrho cov nqi kawm ntawv them, thiab daim pib pub dawb.
