全文获取类型
收费全文 | 166篇 |
免费 | 1篇 |
专业分类
化学 | 90篇 |
晶体学 | 9篇 |
力学 | 3篇 |
数学 | 8篇 |
物理学 | 57篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 1篇 |
2020年 | 2篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 5篇 |
2016年 | 3篇 |
2015年 | 3篇 |
2013年 | 19篇 |
2012年 | 11篇 |
2011年 | 12篇 |
2010年 | 8篇 |
2009年 | 12篇 |
2008年 | 5篇 |
2007年 | 6篇 |
2006年 | 4篇 |
2005年 | 1篇 |
2004年 | 3篇 |
2003年 | 7篇 |
2002年 | 6篇 |
2001年 | 4篇 |
2000年 | 6篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1987年 | 1篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1938年 | 1篇 |
1932年 | 1篇 |
1929年 | 2篇 |
1928年 | 1篇 |
1927年 | 1篇 |
1926年 | 1篇 |
排序方式: 共有167条查询结果,搜索用时 15 毫秒
1.
N. M. Agababyan M. R. Atayan M. Charlet J. Czyżewski E. A. De Wolf K. Dziunikowska A. M. F. Endler Z. Sh. Garutchava H. R. Gulkanyan R. Sh. Hakobyan J. K. Karamyan D. Kisielewska W. Kittel S. S. Mehrabyan Z. V. Metreveli E. C. Oliveira K. Olkiewicz F. K. Rizatdinova E. K. Shabalina L. N. Smirnova M. D. Tabidze L. A. Tikhonova A. V. Tkabladze A. G. Tomaradze F. Verbeure S. A. Zotkin 《Zeitschrift fur Physik C Particles and Fields》1996,71(1):405-414
The NA22 data onπ ? π ? correlations are analyzed in terms of a number of two- and three-dimensional parametrizations (Gaussian space-time, Goldhaber, Bowler string-like, Bertsch hydrodynamical, Kopylov-Podgoretskii, etc.). Contrary to the results obtained for e+e? andµp collisions, the Goldhaber parametrization, as well as string-like models, fail in describing the hadron-hadron data. Better fits are obtained in the framework of surface-emitting fireball-like models, both when including and excluding hydrodynamical expansion of nuclear matter. Our results indicate that pion radiation occurs at earlier stages of matter evolution than in nuclear collisions. 相似文献
2.
3.
W. W. Sułkowski S. Mistarz T. Borecki M. Moczyński A. Danch J. Borek M. Maciążek Anna Sułkowska 《Journal of Thermal Analysis and Calorimetry》2006,84(1):91-97
From the TG data of rubber
granulates, different polyurethane and composites it can be seen that the
thermal decomposition for the rubber granulate and all of the composites start
above 520 K. Two major mass losses for the rubber granulates and majority
of the composites were observed and thermal decomposition is essentially complete
by ~820 K. The changes of activation energies of lower and higher temperature
decomposition, calculated according to the different equations were observed
for a priori assumed first-order reaction for devolatilisation. Differences
between determined and calculated results could suggest a possible reaction
between polyurethane agents and rubber granulate during the composites formations. 相似文献
4.
Collective diffusion in the presence of substrate inhomogeneities and particle–particle interactions
Magdalena A. Załuska-Kotur Łukasz Badowski Filip Krzyżewski Zbigniew W. Gortel 《Journal of Non》2009,355(24-27):1427-1434
A novel variational analytic approach to collective diffusion allowing the density dependent collective diffusion coefficient to be calculated in systems of interacting particles adsorbed on a crystalline substrate is presented. The approach, based on a kinetic lattice gas model extracts the diffusion coefficient directly from the master equations which account for the microscopic kinetics of the system in which microscopic processes underlying the diffusion are particle jumps between neighboring adsorption sites. Variational parameters minimizing the evaluated diffusional eigenvalue of the microscopic rate matrix are ‘geometrical’ and ‘correlational’ phases accounting, for the local potential energy landscape experienced by the adsorbed particle and the local correlations, respectively, i.e. an instantaneous occupation pattern of adsorption sites around the particle. Selected results, collective diffusion as a function of particle coverage, for the system of interacting particles adsorbed on a one dimensional non-homogeneous substrate with steps and for a system of non-interacting particles adsorbed on a two dimensional striped–stepped surface are presented and discussed. It is demonstrated in the latter case that the mean field approach which is known in the literature overestimates the diffusion coefficient and corresponds to the variational result in the limit of infinitely fast hopping kinetics in the direction parallel to steps. 相似文献
5.
The resonanceRaman spectra of Fe(LC 12)3Cl2 and Fe(LC 18)3Cl2 (whereLC 12 andLC 18 denote 4,4′-didodecyloxy-2,2′-bipyridine and 4,4′-dioctadecyloxy-2,2′-bipyridine, respectively) have been measured along with their excitation profiles. The exciting lines of an Ar+ laser have been used. The bands appearing in theRR spectra within 1 200–1 600cm?1 (expected to arise from thebipy moiety C-N and C-C vibrations) suffer the greatest resonance enhancements. Both depolarization ratios of theRaman bands and excitation profiles reveal the interaction of the resonant electronic states. 相似文献
6.
Z. Rzączyńska A. Ostasz M. Sikorska-Iwan H. Głuchowska E. Olszewska S. Pikus 《Journal of Thermal Analysis and Calorimetry》2006,84(3):575-579
The complexes
of yttrium(III) and lanthanides(III) with 1,2,4,5-benzenetetracarboxylic acid
were prepared as crystalline solids of the general formula Ln4(C10H2O8)3⋅14H2O. They
are insoluble in water. On heating in air or inert gas atmosphere all compounds
lose water molecules; next anhydrous compounds decompose to oxides. The yttrium
complex and heavy lanthanide (from Ho to Lu) ones crystallize in monoclinic
crystal system. The dehydration does not change the crystal structure of the
compounds. 相似文献
7.
D. F. Parra P. L. Forster R. Łyszczek A. Ostasz A. B. Lugao Z. Rzączyńska 《Journal of Thermal Analysis and Calorimetry》2013,114(3):1049-1056
The aim of this study has been to gain a fundamental understanding of the mechanisms governing thermal degradation of luminescent poly(3-hydroxybutyrate) (PHB). PHB was doped with diaquatris(thenoyltrifluoroacetonate) europium(III) complex, [Eu(tta)3(H2O)2], and different luminescent systems were obtained. The thermal-stability of the luminescent films was discussed and the products of decomposition were analyzed. Thermal degradation of PHB:Eu(tta)3 x % systems (x = 0, 1, 5, 10, and 15 %) was elucidated by means of thermogravimetric analysis (TG), the thermal-stability decreases with the increase of europium complex concentration. The PHB polymer decomposed with evolution of carbon dioxide and 2-butenoic acid molecules. The TG–FTIR results, of the gaseous degradation products of PHB in nitrogen atmosphere, indicated that the polymer is stable at temperatures up to 200 °C. Polymer matrix at concentrations above 5 % decomposed with evolution of water molecules among the other gaseous products, which implied the presence of a hydrated complex in the system. The luminescent films showed more flexibility due to a loss in crystallinity, which suggested a potential usefulness in technical applications. 相似文献
8.
9.
Zinc(II) and mercury(II) complexes were prepared by reacting isatin-3-thiosemicarbazone (ISTSCH) with zinc(II) acetate or mercury(II) bromide. The complexes were characterized by IR, Raman, diffuse reflectance, 1H and 13C NMR spectra and elemental analysis. Tetrahedral structures for Zn(ISTSC)2 and Hg(ISTSCH)Br2 are suggested. 相似文献
10.
M. Sikorska-Iwan R. Mrozek Z. Rzączyńska 《Journal of Thermal Analysis and Calorimetry》2000,60(1):139-144
The thermal decomposition reactions of manganese(II) complexes with L-proline and 4-hydroxy- L-proline were studied. The Mn(II) proline complex loses the water molecule at 40–95°C and then, heated above 250°C it decomposes
in several steps to manganese oxide. The most appropriate kinetic equations for dehydration process are the geometrical R2
or R3 ones. They give a value of activation energy, E of about 95 kJmol–1. The Mn(II) hydroxyproline complex loses the water molecules in two stages (70–110 and 110–230°C) and next it decomposes
to manganese oxide in several steps. The R3 or D3 (three-dimensional diffusion) models are the most appropriate for the first
stage of dehydration (E is about 155 kJ mol–1). The second step of dehydration is limited by D3 mechanism (E=52 kJ mol–1).
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献