全文获取类型
收费全文 | 60篇 |
免费 | 0篇 |
专业分类
化学 | 47篇 |
数学 | 5篇 |
物理学 | 8篇 |
出版年
2019年 | 1篇 |
2017年 | 1篇 |
2013年 | 1篇 |
2012年 | 1篇 |
2010年 | 1篇 |
2007年 | 1篇 |
2006年 | 1篇 |
2005年 | 2篇 |
2004年 | 2篇 |
2003年 | 1篇 |
2002年 | 3篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1995年 | 5篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 4篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1961年 | 1篇 |
1959年 | 1篇 |
1958年 | 1篇 |
排序方式: 共有60条查询结果,搜索用时 31 毫秒
1.
2.
G. A. Kliger L. S. Glebov A. N. Shuikin V. P. Ryzhikov A. I. Mikaya V. G. Zaikin S. M. Loktev 《Russian Chemical Bulletin》1990,39(2):431-431
Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 493–494, February, 1990. 相似文献
3.
L. S. Glebov A. N. Shuikin A. I. Mikaya V. G. Zaikin A. E. Yatsenko G. A. Kliger S. M. Loktev 《Russian Chemical Bulletin》1988,37(7):1513-1513
Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp, 1695–1696, July, 1988. 相似文献
4.
G. A. Kliger O. A. Lesik V. P. Ryzhikov L. S. Gleb S. M. Loktev 《Russian Chemical Bulletin》1987,36(12):2644-2645
Conclusions 1-Pentanol, 1-dimethylaminopentane or 4-penten-1-o1, 1-pentanol, and 1,5-pentanediol are the major products of the hydroamination of tetrahydrofurfuryl alcohol by dimethylamine and the hydrogenation of this alcohol on a promoted, fused reduced iron catalyst.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2847–2849, December, 1987.The authors express their gratitude to V. G. Zaikin and A. I. Mikaya for assistance in interpreting the mass spectral data. 相似文献
5.
S. V. Golovkin A. P. Kozhevnikov V. P. Kubarovsky A. I. Kulyavtzev V. F. Kurshetsov A. I. Kushnirenko L. G. Landsberg V. V. Molchanov V. A. Mukhin V. I. Solyanik D. V. Vavilov V. A. Victorov M. Ya. Balatz G. V. Dzubenko A. D. Kamenskii G. K. Kliger V. Z. Kolganov V. S. Lakaev G. S. Lomkatzi A. P. Nilov V. T. Smolyankin V. E. Vishnyakov 《Zeitschrift fur Physik C Particles and Fields》1995,68(4):585-594
In the experiments at the SPHINX facility in 70 GeV proton beam of the IHEP accelerator the coherent diffractive production reactions on carbon nucleip+C [(1385)0
K
++C andp+C[0
K
+]+C were investigated. The evidences for new baryon states were obtained in the study of hyperon-kaon effective mass spectra in these two reactions:X (2050) with massM=(2052±6) MeV and width =(35
–35
+22
) MeV inM[(1385)0
K
+] andX(2000) withM=1999±6 MeV and =91±17 MeV inM[0
K
+]. The unusual features of these massive states (small enough decay widths, anomalously large branching ratios for decays with strange particles emission) make them very serious candidates for cryptoexotic pentaquark baryons with hidden strangeness. 相似文献
6.
Optical absorbance changes are commonly used to characterize intermediates which appear in the bleaching sequence of rhodopsin and in the photocycle of bacteriorhodopsin. Absorbance changes can be caused by an intermediate's rotational diffusion, and when this occurs it can distort absorbance changes due to the structural evolution of intermediates. Linear polarization of an optical probe source at 54.7 degrees (the magic angle) relative to the polarization direction of a linearly polarized actinic source has often been used to eliminate signals due to rotational diffusion. We used Jones calculus to investigate the validity of the magic-angle strategy. Taylor expansion of the result in powers of the absorbances of the bleached ground state and of the intermediates leads to a relatively simple expression which can be used to determine whether rotational contributions are likely under various experimental conditions. This expression shows that in first order no dichroism-dependent term appears in the absorbance measured at magic angle. In second order, however, linear dichroism contributes to signals. For the sequence of rhodopsin intermediates: rhodopsin hv----bathorhodopsin in equilibrium BSI----lumirhodopsin, where BSI is a recently discovered blue-shifted intermediate, we determined the magnitude of the dichroism signals to be, on average, less than 2% of the true absorbance change due to the intermediates themselves (and hence undetectable). Freedom from dichroism artifacts in this case results from the fact that the transition dipoles of these intermediates are similar to that of rhodopsin. Larger and certainly detectable dichroism signals are predicted to occur, even at the magic angle, for later intermediates which have transition dipole moments which differ significantly from that of rhodopsin.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
7.
Abstract— Absorbance changes were monitored from 250 to 650 nm during the first microsecond after photolysis of detergent suspensions of bovine rhodopsin at 20°C. Global analysis of the resulting data produced difference spectra for bathorhodopsin, BSI and lumirhodopsin which give the change in absorbance of the aromatic amino acid side chains in these photointermediates relative to rhodopsin. These spectra show that the significant bleaching of absorbance near 280 nm, which has been seen previously for the lumirhodopsin, metarhodopsin I and metarhodopsin II intermediates, extends to times as early as bathorhodopsin. Because no corresponding absorbance increase is observed in the 250-275 nm region, the earliest bleaching of the 280 nm absorbance in rhodopsin is attributed to disruption of a hyperchromic interaction affecting Trp265 . Partial decay of this 280 nm bleaching as bathorhodopsin converts to BSI takes place maximally near 290 nm, where Trp265 has been shown to absorb, and could be due to the ring of the retinylidene chromophore resuming a position at the BSI stage that reestablishes the hyperchromic interaction with Trp265 . A subsequent change in the 250-300 nm region, which has no counterpart in the visible chromophore bands, indicates the possible presence of a protein-localized process as lumirhodopsin is formed. 相似文献
8.
1. | Chemical ionization mass spectra (isobutane) of the positive ions of N-trifluoroacetylamines are characterized by intense peaks of molecular ions and also ions that are typical for the electron impact mass spectra. |
2. | With chemical ionization (reagent gas isobutane or helium) of N-trifluoroacetylamines, low-stability [M + F]– anions are formed. Specific for the primary amines are the anions [M-H]– and [M-alkyl]–. For the derivatives of secondary amines, the anions [M-alkyl]–, [M-alkane]–, and [M-alkyl s-alkene]–; for the derivatives of cyclic amines, the anions [M-H]– and ions formed as a result of ring cleavage. |
9.
Abstract— The long lived triplets from all-trans retinal and 11-cis retinal are quenched by a nitroxyl radical, 4-hydroxy-2,2,6,6-tetramethylpiperidinoyl, with essentially identical rate constants. The rates vary with solvent but do not correlate with solvent polarity. The results confirm implications of earlier work with oxygen quenching and are compatible with the view that isomerization occurs in non-relaxed triplets or that the triplet (or triplets) observed spectroscopically decay by way of a single triplet state which has a small electronic energy gap to ground state isomers. 相似文献
10.
Evanescent random fields arise as a component of the 2D Wold decomposition of homogeneous random fields. Besides their theoretical importance, evanescent random fields have a number of practical applications, such as in modeling the observed signal in the space-time adaptive processing (STAP) of airborne radar data. In this paper we derive an expression for the rank of the low-rank covariance matrix of a finite dimension sample from an evanescent random field. It is shown that the rank of this covariance matrix is completely determined by the evanescent field spectral support parameters, alone. Thus, the problem of estimating the rank lends itself to a solution that avoids the need to estimate the rank from the sample covariance matrix. We show that this result can be immediately applied to considerably simplify the estimation of the rank of the interference covariance matrix in the STAP problem. 相似文献