全文获取类型
收费全文 | 79篇 |
免费 | 0篇 |
专业分类
化学 | 56篇 |
晶体学 | 1篇 |
物理学 | 22篇 |
出版年
2011年 | 2篇 |
2008年 | 1篇 |
2007年 | 1篇 |
2006年 | 4篇 |
2004年 | 1篇 |
2003年 | 1篇 |
1999年 | 1篇 |
1996年 | 1篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 4篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1977年 | 1篇 |
1976年 | 4篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 11篇 |
1972年 | 8篇 |
1971年 | 3篇 |
1970年 | 6篇 |
1969年 | 3篇 |
1967年 | 1篇 |
排序方式: 共有79条查询结果,搜索用时 15 毫秒
1.
On the Constitution of Silicate Anions in Tetraethylammonium Silicates and their Aqueous Solutions Investigations by paperchromatography, 29Si-NMR spectroscopy and trimethylsilylation method show that concentrated solutions of tetraethylammonium (TEA) silicates with molar TEA:Si ratios from 2.8 to 1 contain mainly double three-ring silicate anions. Besides of these small amount of mono-, di-, tri-, tetra-, cyclotri-, cyclotetra-, double four-ring- and other polycyclic silicate anions are present. From these solutions a crystalline double three-ring silicate of the formula [N(C2H5)4]6[Si6O15] · 57 H2O could be obtained by crystallization at low temperature. Concentrated solutions with TEA:Si ratios of 0.8 to 0.6 contain mainly double three-, double four-, double five- an probably double six-ring silicate anions. From such solutions always the solid TEA-double four-ring silicate is obtained by crystallization. The reasons for the prefered formation of double ring silicate anions in TEA-silicate solutions and their crystallization are discussed. 相似文献
2.
High-resolution 29Si NMR spectra of zunyite Si5Al13O20 (OH,F)18Cl have been studied by magic-angle sample spinning in combination with high-power proton decouplina and polarization transfer. The isotropic 29Si chemical shift depends mainly on the number of Si-O-Si bridges and the bond angles in these bridges connecting the different SiO4 tetrahedra. 相似文献
3.
4.
5.
6.
T. Pehk E. Lippmaa V. V. Sevostjanova M. M. Krayuschkin A. I. Tarasova 《Magnetic resonance in chemistry : MRC》1971,3(6):783-790
The carbon-13 chemical shifts of mono- and 1,3-disubstituted adamantanes are reported. The effects caused by the substituents are compared with those met in aliphatic and alicyclic compounds. It is shown that the 1,4-interactions have only minor importance in l-substituted adamantanes. The influence of polar groups on the chemical shifts of γ- and δ-carbon atoms is a typical ‘through-the-bonds’ interaction and correlates with inductive parameters of the substituents. 相似文献
7.
Horiba K Taguchi M Chainani A Takata Y Ikenaga E Miwa D Nishino Y Tamasaku K Awaji M Takeuchi A Yabashi M Namatame H Taniguchi M Kumigashira H Oshima M Lippmaa M Kawasaki M Koinuma H Kobayashi K Ishikawa T Shin S 《Physical review letters》2004,93(23):236401
Using hard x-ray (HX; hnu=5.95 keV) synchrotron photoemission spectroscopy (PES), we study the intrinsic electronic structure of La(1-x)Sr(x)MnO(3) (LSMO) thin films. Comparison of Mn 2p core-levels with soft x-ray (SX; hnu approximately 1000 eV) PES shows a clear additional well-screened feature only in HX PES. Takeoff-angle dependent data indicate its bulk (> or =20 A) character. The doping and temperature dependence track the ferromagnetism and metallicity of the LSMO series. Cluster model calculations including charge transfer from doping-induced states show good agreement, confirming this picture of bulk properties reflected in Mn 2p core-levels using HX PES. 相似文献
8.
Splitting of Mössbauer lines has been observed in conventional energy domain spectra of Permalloy samples when an external radio frequency (rf) magnetic field was tuned to be in resonance with the separation of Zeeman sublevels of either the ground or the excited state of the57Fe nucleus. Time domain measurements were performed with the frequency of the rf field close to the natural linewidth of the 14.4 keV Mössbauer state. A nonmagnetostrictive magnetically soft Permalloy sample was used in the experiments. 相似文献
9.
10.
Summary We have studied the time dependence of M?ssbauer absorption in a magnetically soft sample of Fe18Ni82 permalloy under the influence of a radio-frequency (r.f.) magnetic field. Absorption was measured as a function of the r.f.
field phase at specific gamma-ray energies. We have shown that measuring the time dependence of absorption makes it possible
to differentiate between purely magnetic and magnetoacoustic modulation mechanisms even in cases where clear distinction is
not visible in conventional energy domain spectra.
Paper presented at ICAME-95, Rimini, 10–16 September 1995. 相似文献