全文获取类型
收费全文 | 61篇 |
免费 | 1篇 |
专业分类
化学 | 40篇 |
晶体学 | 2篇 |
数学 | 1篇 |
物理学 | 19篇 |
出版年
2023年 | 1篇 |
2020年 | 1篇 |
2019年 | 2篇 |
2018年 | 1篇 |
2014年 | 1篇 |
2013年 | 2篇 |
2012年 | 4篇 |
2011年 | 6篇 |
2010年 | 1篇 |
2009年 | 2篇 |
2008年 | 2篇 |
2007年 | 2篇 |
2006年 | 4篇 |
2005年 | 2篇 |
2004年 | 4篇 |
2003年 | 3篇 |
2001年 | 2篇 |
2000年 | 5篇 |
1999年 | 2篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1975年 | 1篇 |
1939年 | 1篇 |
1932年 | 1篇 |
1924年 | 2篇 |
1923年 | 1篇 |
排序方式: 共有62条查询结果,搜索用时 15 毫秒
31.
Mamone G Caira S Garro G Nicolai A Ferranti P Picariello G Malorni A Chianese L Addeo F 《Electrophoresis》2003,24(16):2824-2837
We report a fast and easy-to-use procedure that combines polyacrylamide gel electrophoresis with matrix assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF) and nanoelectrospray-tandem mass spectrometry (nES-MS/MS) analysis for the identification of casein components and defined phosphorylated sites. This methodology ensured identification of more than 30 phosphorylated proteins, five beta-, fifteen alpha(s1)-, ten alpha(s2)-, and four kappa-casein (CN) components, including nonallelic, differently phosphorylated, and glycosylated forms. The sugar motif covalently bound to kappa-CN was identified as chains, trisaccharide GalNAc, Gal, NeuGc, and tetrasaccharide 1GalNAc, 1Gal, 2NeuGc. Also identified was a biantennary chain made up of both chains of trisaccharide 1GalNAc, 1Gal, 1NeuGc, and tetrasaccharide 1GalNAc, 1Gal, 2NeuGc moiety on a single kappa-CN component. The phosphate group on site Ser12 of tryptic peptide 8-22 of most phosphorylated alpha(s1)-CN (11 phosphate groups) was localized and the oligosaccharide sequence of the main tryptic glycopeptides of two kappa-CN components was determined by means of MS/MS analysis. 相似文献
32.
Yamila Garro Linck M. H. M. Killner E. Danieli B. Blümich 《Applied magnetic resonance》2013,44(1-2):41-53
Biodiesel produced mainly by the base-catalyzed transesterification of vegetable oils or animal fats with a short chain alcohol, has become an attractive alternative to petroleum-based diesel fuel. Even though high-field 1H nuclear magnetic resonance (NMR) is a reliable method for biodiesel quality control, it is restricted by its poor mobility and expensive superconducting coils. As an alternative, this study presents a mobile low-field 1H NMR spectrometer for the analysis of biodiesel samples derived from different feedstock oils. The low-field 1H NMR spectra of all the compounds coexisting in a typical transesterification reaction such as rapeseed oil, rapeseed biodiesel, methanol, and glycerol, could be clearly differentiated. Field-dependent characteristic parameters such as relaxation times are provided. The degree of saturation of the different biofuels samples could be reliably estimated via integration of the resolved signals of the spectra. The obtained results agreed well with those measured at high-field 1H NMR. Since this compositional information is directly related to the biodiesel properties, the presented mobile low-field 1H NMR device built from permanent magnets arrayed in a Halbach geometry, constitutes an excellent alternative tool for biodiesel quality control. 相似文献
33.
G Garro P Ferranti S De Pascale MA Nicolai R Mauriello M Quarto F Pilla L Chianese 《Electrophoresis》2012,33(15):2337-2344
A genetic survey on three autochthonous goat breeds reared in Italy was carried out by a proteomic approach. This methodology, further to providing the phenotypic frequency of identified α(s1) genetic variants, allowed to determine (i) the additional constitutive presence of a non-allelic 'α(s1) -casein (CN) F like' protein in goat 'strong' α(s1) variants; (ii) an α(s1) -CN B(2) like protein, expressed at very low quantitative level, in goat 'weak' α(s1) -CN variants, and, as main focus; (iii) the occurrence of a new α(s1) -CN D(1) variant characterised by the lack of α(s1) (f59-69) sequence otherwise encoded by exon 9 in goat α(s1) B(2) reference. The same exon skipping event had been identified since 1990, as responsible of the 'weak quantitative class' of α(s1) -CN D variant (0.6 g/L), while the new α(s1) -CN D(1,) has been 'quantitatively' classified as an 'intermediate' variant, since 1.8 g/L per allele was assessed in the milk. 相似文献
34.
A series of racemic 4-aryl-5-(tert-butoxycarbonyl)-6-methyl-3,4-dihydro-2(1H)-pyridones have been prepared by means of a modified Hantzsch reaction using commercially available starting materials. An easy removal of the tert-butyl group of these pyridones and subsequent reaction with cesium carbonate and chloromethyl 2-methylpropanoate provided us suitable substrates (±)-5 to be used in lipase-catalyzed hydrolysis reactions. Lipase B from Candida antarctica (CAL-B) was the most adequate lipase in the hydrolysis of (±)-5. Despite the low enantioselectivity values obtained (E≤12), several optically active pyridone derivatives were finally isolated with high enantiomeric excesses (ee≥91%) and moderate yields. 相似文献
35.
J. Segura‐Ruiz G. Martinez‐Criado J. A. Sans R. Tucoulou P. Cloetens I. Snigireva C. Denker J. Malindretos A. Rizzi M. Gomez‐Gomez N. Garro A. Cantarero 《固体物理学:研究快报》2011,5(3):95-97
Using synchrotron radiation nanoprobe, this work reports on the elemental distribution in single Inx Ga1–xN nanowires (NWs) grown by molecular beam epitaxy directly on Si(111) substrates. Single NWs dispersed on Al covered sapphire were characterized by nano‐X‐ray fluorescence, Raman scattering and photoluminescence spectroscopy. Both Ga and In maps reveal an inhomogeneous axial distribution inside sin‐ gle NWs. The analysis of NWs from the same sample but with different dimensions suggests a decrease of In segregation with the reduction of NW diameter, while Ga distribution seems to remain unaltered. Photoluminescence and Raman scattering measurements carried out on ensembles of NWs exhibit relevant signatures of the compositional disorder. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
36.
J. C. Garro Martinez M. F. Andrada M. R. Estrada E. A. Castro G. N. Zamarbide Z. Mucsi I. G. Csizmadia 《Journal of Physical Organic Chemistry》2008,21(5):409-418
A general structure, substituent and activity relationship of the following type has been fitted to the available ED50 values of cyclic enaminone antiepileptic compounds: . In this relationship ‘structure’ was quantified by d, the distance measured between the carbonyl oxygen and the first atom of the aromatic ring. The ‘substituent’ was quantified by Hammett substituent constant: (σ). With the aid of the above function of two independent variables, a new molecular structure was predicted by extrapolation that has shown about two orders of magnitude greater activity than the most active molecule in the original set with measured ED50 values. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
37.
38.
39.
40.
Héctor Novoa de Armas Norbert M. Blaton Oswald M. Peeters Camiel J. De Ranter Margarita Suárez Estael Ochoa Yamila Verdecia Esperanza Salfrán 《Journal of chemical crystallography》2000,30(4):237-243
The synthesis and structural characterization of Methyl 6-chloro-4-(2-chlorophenyl)-5-formyl-2-methyl-1,4-dihydropyridine-3-carboxylate is described. The structure was refined to R1 = 0.0470 for 2665 reflections (with I > 2(I)). Crystal data: C15H13C12NO3, monoclinic,space group P21/c, a = 11.163(9), b = 14.484(8), c = 9.422(7) Å, V = 1512.9(19) Å3, Z = 4. The results of crystallographic and molecular modeling (AM1) were compared. The Cl atom attached to the phenyl group has two possible orientations, having 75% (sp) and 25% (ap) occupancy, respectively. The molecules in the crystal are held together by means of intermolecular hydrogen bonds of the type N=H...O and by C=H...O interactions. 相似文献