نتایج جستجو برای: fluorination

تعداد نتایج: 1361  

Rouhani, Kamelia,

یکی از مهمترین دست آوردهای تکنولوژی غذایی، تصفیه شکر از نیشکر و چغندر بوده است. بین سال های ۱۸۷۰ و ۱۹۱۰، شکر یک ماده غذایی ارزان قیمت شد و به خاطر شیرینی، در دسترس بودن به اشکال مختلف و مفید بودن به عنوان یک ماده غذایی قابل نگهداری به خوبی مورد قبول واقع شد. ولی نتیجه بعدی و ناشناخته این دسترسی آسان به شکر، افزایش خرابی و پوسیدگی دندانها بود. بررسی های اپیدمیولوژیکی نشان داد که تا سال های ۱۹۳۰ ...

Journal: :International journal of radiation applications and instrumentation. Part A, Applied radiation and isotopes 1988
J D Herscheid R Wedzinga W Verboom G W Visser

The fluorination of 1,4-benzo- and naphthoquinones using [18F]acetylhypofluorite is described. For compounds with electron-donating substituents fair to good radiochemical yields have been reached.

Journal: :Journal of prosthodontics : official journal of the American College of Prosthodontists 2016
Stewart W Pharr Erica C Teixeira Ronald Verrett Jeffrey R Piascik

PURPOSE Porcelain chipping has been one of the main problems of porcelain-fused-to-zirconia restorations. This study evaluates the bond strengths of layered, pressed, and adhesively bonded porcelain to yttria-stabilized zirconia substrates that have undergone traditional preparation or gas-phase fluorination. MATERIALS AND METHODS A three-point bending test was used to evaluate the bond stren...

Journal: : 2023

The influence of the dipole polarization carbon film coatings on their secondary electron emission has been studied. It is shown that plasma fluorination with low specific surface resistance obtained in microwave low-pressure ethanol vapor increases work function by 0.6 eV and reduces more than a factor two. results can be used to obtain collectors anti-emission grid electrodes high-power elect...

Journal: :Angewandte Chemie 2010
Pazhamalai Anbarasan Helfried Neumann Matthias Beller

Selective functionalization reactions of aromatic and heteroaromatic halides with carbon, oxygen, and nitrogen nucleophiles have attracted much attention in the last decades. In addition to typical metal-catalyzed coupling reactions, direct functionalization of aryl halides through the formation of Grignard reagents offer new ways for the efficient construction of biologically interesting carbo...

Journal: :Pure and applied chemistry. Chimie pure et appliquee 1970
D H Barton

The application of hypofluorites (fluoroxy-compounds), especially tnfluoromethyl hypofluorite, in the synthesis of fluorinated steroids is described. Hypofluorites are powerful but selective fluorinating agents with unusual electrophilic character. They should find considerable application not only in the synthesis of fluorinated steroids, but for preparation of fluorinated compounds of many di...

Journal: :Bulletin of the Chemical Society of Japan 1977

Journal: :Organic & Biomolecular Chemistry 2019

Journal: :Physical chemistry chemical physics : PCCP 2016
Nitzan Mayorkas Hanan Sachs Markus Schütz Shun-ichi Ishiuchi Masaaki Fujii Otto Dopfer Ilana Bar

Vibronic and vibrational spectra of 2-(2-fluoro-phenyl)-ethylamine (2-FPEA) conformers were measured in a molecular beam by resonant two-photon ionization (R2PI), ultraviolet-ultraviolet hole burning (UV-UV HB) spectroscopy, and ionization-loss stimulated Raman spectroscopy (ILSRS). The measured ILSR spectral signatures in the survey spectra of the amino group region and in the broad spectral r...

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