نتایج جستجو برای: معماری nmr
تعداد نتایج: 68192 فیلتر نتایج به سال:
The utility of infrared (IR) spectroscopy for the determination of strawberry ripeness has been successfully demonstrated. Transmission IR spectra were collected using dried liquid extracts from strawberry flesh. The overall IR feature provided fairly noticeable differences, and the ripeness stage was clearly identified using principal component analysis (PCA). Although all of the extracted com...
phytochemical investigation of the aerial parts of euphorbia erythradenia bioss. (euphorbiaceae), one of iranian endemic euphorbias, with particular attention to triterpene constituents, using methanol solvent extraction was carried out. five known triterpenes, including four cycloartanes and oleanolic acid, were isolated for the first time and identified using nmr and mass techniques. anti hiv...
the forced degradation study of lidocaine hcl was carried out according to the ich guideline q1a (r2). the degradation conditions were assessed to be hydrolysis, oxidation, photolysis and dry heat during 24 h, 48 h and 72 h and then the samples were investigated by gc-fid method and nuclear magnetic resonance (nmr) spectroscopy. according to these results, the degradation products were not obse...
in this study, b12n12 nano ring has been selected because it consist of four 6-side rings and polar bonds b-n which in comparison with non-polar bonds c-c, is more suitable for the study of the absorption of other compounds. so reactivity and stability of benzene alone and in the presence b12n12 nano ring field checked. to determine the non-bonded interaction energies between benzene and b12n12...
adsorption of co2 on the surface of single-wall zigzag (5,0) and armchair (4,4) carbon nanotubes (swcnts) were studied through using density functional theory (dft) calculations. optimizations of geometric were performed at the b3pw91 level of 6-311++g** method standard basis set using gaussian 03 package of program [1]. structural models were optimized and adsorption energies, band gap, charge...
to investigate non-bonded interaction of phenanthrene and bn nanostructure, geometric structure of phenanthrene and b12n12 nano-ring with b3lyp method and 6-31g* basis set are optimized by using ab initio gaussian quantum chemical package. the main purpose of this study was to evaluate changes of electronic properties of aromatic compound in presences nano ring field. therefore reactivity and s...
objective during the last three decades sesquiterpenoid lactones have emerged as one of the largest groups of plant products with over 3000 naturally occurring substances known. the genus artemisia characteristically contains this biologically active type of secondary metabolites. with respect to increasing interest in the cytotoxic, antibiotic, phototoxic and antineoplastic activities of sesqu...
A mononuclear platinum(II) complex with two monodentate-S H4tg(-) ligands, [Pt(H4tg-κS)2(bpy)] (1), was newly synthesized by the reaction of [PtCl2(bpy)] (bpy = 2,2'-bipyridyl) with NaH4tg (NaH4tg =1-thio-β-d-glucose sodium salt) in water. Complex 1 reacted with additional [PtCl2(bpy)] in water to give an S-bridged dinuclear complex, [Pt2(μ2-H4tg-κ(1)S:κ(1)S)2(bpy)2](2+) ([2](2+)), in which a s...
A combination of X-ray crystallography, (6)Li, (15)N, and (13)C NMR spectroscopies, and density functional theory computations affords insight into the structures and reactivities of intervening aggregates underlying highly selective asymmetric alkylations of carboxylic acid dianions (enediolates) mediated by the dilithium salt of a C2-symmetric chiral tetraamine. Crystallography shows a trilit...
بناهایفرم مفهومی پویا و لغزان است که از هریک گفتمانهای مختلف معماری تلقی متفاوتی آن بهدست آمده است. در این مقاله با هدف بازاندیشی مفهومِ فرم گفتمان معاصر، به تبیین زیربنای نظری اقتضائات قابلیت پرداخته شده بدین منظور نخست برخی نیروهای بنیادین مؤثر بر تحول مفهوم دوران معاصر شناسایی شدهاند؛ سپس بهمثابة تلقیای پاسخگویی ذکرشده را ممکن میکند، معرفی گردیده است؛ ادامه حضور طریق بسط نوشتار مسیر مع...
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