全文获取类型
收费全文 | 375篇 |
免费 | 1篇 |
国内免费 | 1篇 |
专业分类
化学 | 157篇 |
晶体学 | 3篇 |
力学 | 34篇 |
数学 | 35篇 |
物理学 | 148篇 |
出版年
2021年 | 5篇 |
2020年 | 7篇 |
2019年 | 8篇 |
2018年 | 7篇 |
2017年 | 13篇 |
2016年 | 16篇 |
2015年 | 8篇 |
2014年 | 9篇 |
2013年 | 15篇 |
2012年 | 20篇 |
2011年 | 29篇 |
2010年 | 22篇 |
2009年 | 22篇 |
2008年 | 14篇 |
2007年 | 18篇 |
2006年 | 7篇 |
2005年 | 6篇 |
2004年 | 3篇 |
2003年 | 9篇 |
2002年 | 8篇 |
2001年 | 20篇 |
2000年 | 8篇 |
1999年 | 7篇 |
1998年 | 2篇 |
1996年 | 2篇 |
1994年 | 5篇 |
1993年 | 7篇 |
1992年 | 6篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1986年 | 4篇 |
1985年 | 7篇 |
1984年 | 3篇 |
1983年 | 4篇 |
1981年 | 2篇 |
1980年 | 5篇 |
1978年 | 6篇 |
1977年 | 5篇 |
1973年 | 2篇 |
1972年 | 1篇 |
1971年 | 5篇 |
1970年 | 2篇 |
1968年 | 2篇 |
1967年 | 3篇 |
1966年 | 2篇 |
1961年 | 2篇 |
1960年 | 1篇 |
1959年 | 3篇 |
排序方式: 共有377条查询结果,搜索用时 46 毫秒
371.
Vorontsov EA Samgina TY Gorshkov VA Poljakov NB Nifant'ev IE Lebedev AT 《European journal of mass spectrometry (Chichester, England)》2011,17(1):73-83
Long disulphide-containing peptides brevinins 1E and 2Ec from the skin secretion of the frog Rana ridibunda were reduced and alkylated with ten novel and three known derivatizing agents. Nine of novel reagents are maleimide derivatives. The peptides were also reduced with DTT directly onto the MALDI target without alkylation. Modified samples were subjected to MALDI-PSD study. Procedures, fragmentation patterns, fragment ion signal abundances and sequence coverage for two peptides modified with thirteen tags (or on-plate reduced) are described. The fast on-plate procedure for reduction/alkylation was applied to Rana ridibunda crude secretion, providing intensive signals of derivatized peptides. The corresponding ions may be used for the MS/MS sequencing procedure. 相似文献
372.
T. E. Kokina L. A. Sheludyakova A. V. Tkachev E. G. Boguslavskii A. M. Agafontsev N. B. Gorshkov S. V. Larionov 《Russian Journal of General Chemistry》2011,81(8):1651-1657
Coordination compounds Cu2(H2L1)Cl4 (I), Pd2(H2L1)Cl4 (II), Cu2(H2L2)Cl4 (III), and Pd2(H2L2) Cl4 (IV) with chiral bis-α-sulfanyloximes, the derivatives of the monoterpenoid (−)-α-pinene, were obtained. The complexes I and III are paramagnetic (μeff = 2.45 and 2.67 μB, respectively), II and IV are diamagnetic. According to IR spectroscopy, in the compounds I–IV the nearest environment of Cu and Pd atoms includes
N, S, and Cl atoms. The values of μeff and parameters of ESR spectra of the solid phase and solutions of I and III show a binuclear structure of the Cu(II) complexes. Parameters of the 1H and 13C NMR spectra of compounds II and IV indicate the formation of binuclear Pd(II) complexes of C
2 symmetry and the closure of fivemembered chelate rings PdNSC2. The PdCl2 fragments are in transoid position. H2L1 and H2L2 are tetradentate bridging chelating ligands. 相似文献
373.
T. Yu. Samgina V. A. Gorshkov Ye. A. Vorontsov E. V. Demkina S. V. Ogourtsov V. V. Shakhparonov G. I. El-Registan A. T. Lebedev 《Journal of Analytical Chemistry》2011,66(14):1361-1368
Skin secretory amphibian antimicrobial peptides are the part of their immune defense. The present work is devoted to the study
of the influence of “water environment stress” and additional bacterial impact on the composition of the skin secretion of
the Common frog (Rana temporaria) by means of high-performance liquid chromatography (HPLC) and matrix assisted laser desorption/ionization (MALDI) mass spectrometry.
It was shown that the contact of the amphibian species with Micrococcus luteus and Staphylococcus aureus stimulates the release of antimicrobial peptides, maintains the high bradykinin and related peptides levels in the skin secretion
and influences the processing of the latter ones. The possibilities of mass spectrometric profiling by using HPLC and MALDI
were demonstrated. This feature allows the detection of potentially bioactive peptides for their future direct testing, as
has been shown for temporin M and brevinin 1Tb in the present study. 相似文献
374.
Tatiana Y. Samgina Egor A. Vorontsov Vladimir A. Gorshkov Konstantin A. Artemenko Roman A. Zubarev Jimmy A. Ytterberg Albert T. Lebedev 《Journal of the American Society for Mass Spectrometry》2013,24(7):1037-1044
Collision-induced dissociation (CID) spectra of long non-tryptic peptides are usually quite complicated and rather difficult to interpret. Disulfide bond formed by two cysteine residues at C-terminus of frog skin peptides precludes one to determine sequence inside the forming loop. Thereby, chemical modification of S–S bonds is often used in “bottom up” sequencing approach. However, low-energy CID spectra of natural non-tryptic peptides with C-terminal disulfide cycle demonstrate an unusual fragmentation route, which may be used to elucidate the “hidden” C-terminal sequence. Low charge state protonated molecules experience peptide bond cleavage at the N-terminus of C-terminal cysteine. The forming isomeric acyclic ions serve as precursors for a series of b-type ions revealing sequence inside former disulfide cycle. The reaction is preferable for peptides with basic lysine residues inside the cycle. It may also be activated by acidic protons of Asp and Glu residues neighboring the loop. The observed cleavages may be quite competitive, revealing the sequence inside disulfide cycle, although S–S bond rupture does not occur in this case. Figure
? 相似文献
375.
Anton A. Goloborodko Lev I. Levitsky Mark V. Ivanov Mikhail V. Gorshkov 《Journal of the American Society for Mass Spectrometry》2013,24(2):301-304
Pyteomics is a cross-platform, open-source Python library providing a rich set of tools for MS-based proteomics. It provides modules for reading LC-MS/MS data, search engine output, protein sequence databases, theoretical prediction of retention times, electrochemical properties of polypeptides, mass and m/z calculations, and sequence parsing. Pyteomics is available under Apache license; release versions are available at the Python Package Index http://pypi.python.org/pyteomics, the source code repository at http://hg.theorchromo.ru/pyteomics, documentation at http://packages.python.org/pyteomics. Pyteomics.biolccc documentation is available at http://packages.python.org/pyteomics.biolccc/. Questions on installation and usage can be addressed to pyteomics mailing list: pyteomics@googlegroups.com 相似文献
376.
M. Yu. Chaika T. A. Kravchenko E. V. Bulavina V. S. Gorshkov A. B. Yaroslavtsev 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2011,85(6):1065-1071
The formation of copper nanoparticles in a KU-23 15/100 sulfocation-exchanger was studied. It was demonstrated that the formation
of copper as assemblies from nanoparticles with sizes of 3 to 10 nm during chemical synthesis is determined by the nature
of the polymer and does not depend on the amount of metal precipitated. The percolation threshold of electron conductivity,
which determines the formation of electrochemical activity of nanocomposites, was discovered. It was determined that the electroreduction
of molecular oxygen takes place on the surface and in the subsurface zone of a nanocomposite grain, the size of which is determined
by the local concentration of metal particles in the ion-exchanger phase. 相似文献
377.
Yu. G. Chukalkin A. E. Teplykh D. G. Kellerman V. S. Gorshkov 《Physics of the Solid State》2010,52(5):1006-1009
The structures and magnetic states of stoichiometric lithium manganite LiMn2O4 and manganites and titanates Li1.33Mn1.67O4 and Li1.33Ti1.67O4 with excess lithium in both the initial (as-synthesized) state and after irradiation by fast (E
eff ≥ 1 MeV) neutrons with a fluence of 2 × 1020 cm−2 have been studied using neutron diffraction, X-ray diffraction, and magnetic methods. It has been established that the irradiation
brings about a noticeable redistribution of manganese, titanium, and lithium cations over nonequivalent tetrahedral (8a) and octahedral (16d) positions of a spinel lattice. This structural disorder causes a radical change in the physical properties of the materials
under study. The charge order existing in the initial LiMn2O4 sample is destroyed. There arises a strong intersublattice indirect exchange interaction Mn(8a)-O-Mn(16d). The disorder is accompanied by the antiferromagnet-ferrimagnet (LiMn2O4) and paramagnet-ferrimagnet (Li1.33Mn1.67O4) magnetic transitions. 相似文献