نتایج جستجو برای: kbr
تعداد نتایج: 750 فیلتر نتایج به سال:
هالوژندار کردن ترکیبات آروماتیک از مهمترین واکنش های شیمی آلی می باشد در سنتز مواد الی از اهمیت بسزایی برخوردار است. و برای سنتز مواد مختلف طبیعی و دارویی استفاده می شود. در این پژوهش از واکنشگر ارتو زایلین بیس تری فنیل فسفونیوم پراکسو دی سولفات برای هالوژن دار کردن بعضی از ترکیبات آروماتیک استفاده شده است و در مجاورت ..برخی از حلقه های آروماتیک فعال نظیر متوکسی بنزنها ، فنل ها و آمین ها با ران...
When studying the colloidal stability of an immunolatex formed by F(ab')2 protein fragments and a polystyrenepolychloromethylstyrene copolymer, striking results were obtained. After the expected particle aggregation induced by an increase in the electrolyte concentration (KBr), subsequent restabilization occurred when this electrolyte concentration was increased even more. This non-DLVO behavio...
Colorless needles of the arsenite bromide La3OBr[AsO3]2 were synthesized from ammonium dihydrogen arsenate, ammonium bromide and lanthanum oxide in an NaBr/KBr flux at 900 ◦C. La3OBr[AsO3]2 crystallizes with the centrosymmetric tetragonal La3OCl[AsO3]2 type, space group P42/mnm. The structure was refined from single-crystal diffractometer data: a = 13.0431(15), c = 5.6127(7) Å, wR2 = 0.0454, 94...
Bailey, Glen F. (Western Regional Research Laboratory, Albany, Calif.), Saima Karp, and L. E. Sacks. Ultraviolet-absorption spectra of dry bacterial spores. J. Bacteriol. 89:984-987. 1965.-The possibility of obtaining reasonably satisfactory ultraviolet-absorption spectra of dry spores embedded in KBr has been demonstrated. Such spectra show the three peaks characteristic of calcium dipicolinat...
We have used reliable computer simulation techniques and accurate lattice and defect interionic potentials to calculate the binding energies of a range of possible structures for clusters involving two or more dopant cations for NaCI, KC1 and KBr containing Mg2+ and for the NaCl : BaZt system. Aggregation mechanisms involving both nn and nnn dipoles have been considered and the relative importa...
The individual impacts of slow (300 eV/amu) highly charged Xe ions induce nanometer sized pitlike structures on the KBr (001) surface. The volume of these structures shows a strong dependence on the ions potential energy. Total potential sputter yields from atomically flat (001) terraces are determined by imaging single ion impact sites. The dependence of the sputter yield on the ions initial c...
All commercially available reagents were used as received. Solvents were distilled before use. The obtained compounds were fully characterized by standard analytical methods using a Varian Mercury 300 NMR spectrometer for H(300 MHz) and F-NMR spactra (282 MHz) in deuteric solvents. Mass spectrometric data were recorded on Finnigan SSQ 7000 and Thermo Deca XP as EI (70 eV) or ESI. IR spectra wer...
A sustainable V(V) and Mo(VI) catalysed two-phase procedure for bromination of toluene under quite mild conditions is proposed; H2O2 is the primary oxidant and KBr is the bromine source; metal precursors are commercially available salts. The reaction is efficient without any additional solvent. By using PhCH3 as a solvent/substrate good yields, together with interesting selectivity toward the f...
The most abundant geometries and relative stabilities of alkali halide clusters with a (XY)(n) (o) configuration (e.g., LiF, NaCl, KBr) are described. Five main series were obtained: linear, cyclic, cubic, arc strips and nanotubes. The stability analysis shows that higher members are likely to be formed from the lower member of the same series and/or from two building blocks (n = 1, 2). The ene...
The initiation of germination of Bacillus megaterium QM B1551 spores, grown in supplemented nutrient broth, has been studied. The initiation properties depend on buffer concentrations and the particular batch of spores. Initiation in l-alanine, KBr, calcium dipicolinate, or in buffer alone increases as a function of the spore age; whereas initiation in glucose, l-leucine, or l-proline remains r...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید