全文获取类型
收费全文 | 149篇 |
免费 | 0篇 |
专业分类
化学 | 52篇 |
力学 | 1篇 |
数学 | 6篇 |
物理学 | 90篇 |
出版年
2022年 | 1篇 |
2020年 | 1篇 |
2018年 | 1篇 |
2015年 | 1篇 |
2013年 | 2篇 |
2010年 | 1篇 |
2009年 | 3篇 |
2008年 | 3篇 |
2007年 | 6篇 |
2006年 | 11篇 |
2005年 | 3篇 |
2004年 | 4篇 |
2003年 | 6篇 |
2002年 | 2篇 |
2001年 | 11篇 |
2000年 | 5篇 |
1999年 | 2篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 5篇 |
1994年 | 7篇 |
1993年 | 3篇 |
1992年 | 5篇 |
1991年 | 7篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 4篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 4篇 |
1981年 | 5篇 |
1980年 | 4篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 4篇 |
1976年 | 7篇 |
1975年 | 3篇 |
1974年 | 5篇 |
1973年 | 1篇 |
1889年 | 1篇 |
排序方式: 共有149条查询结果,搜索用时 125 毫秒
1.
2.
3.
Measurements are reported on the thermodynamic properties for the acid ionisation of various carboxylato-pentammine cobalt(III) ions, where the organic ligand is a dicarboxylate ion ?OCORCOOH. It is shown that the results can be correlated with the ionisation of the free acids, on the basis of a simple electrostatic model. Results are also reported on the enthalpies of hydrolysis of the same ions, obtained indirectly from the enthalpies of reaction with sodium sulphide. The results for the complexes of the dicarboxylic acids which were studied (maleato, phthalato, fumarato, succinato and malonato) are not very different, while the acetato complex is somewhat more unstable. There is some indication that the complexes which hydrolyse faster are also thermodynamically less stable. 相似文献
4.
5.
6.
H. Weisen F. Hofmann M. J. Dutch J. -M. Moret J. B. Lister A. Pochelon R. A. Pitts M. Anton R. Behn S. Bernel F. Bühlmann R. Chavan B. P. Duval D. Fasel A. Favre S. Franke A. Heym Ch. Hollenstein P. Isoz B. Joye X. Llobet B. Marletaz Ph. Marmillod Y. Martin Ch. Nieswand P. J. Paris A. Perez Z. A. Pietrzyk O. Sauter W. Van Toledo G. Tonetti M. Q. Tran F. Troyon D. J. Ward 《Czechoslovak Journal of Physics》1995,45(12):1095-1110
During the first two years of operation, the TCV tokamak has produced a large variety of plasma shapes and magnetic configurations, with 1.0B
tor1.46T,I
p800kA,k2.05, –0.71. A new shape control algorithm, based on a finite element reconstruction of the plasma current in real time, has been implemented. Vertical growth rates up to 1000s–1 have been stabilized using the external coil system. Ohmic H-modes with Troyon factors (
tor
aB/I
p) up to two and densities up to 2.25×1020m–3, corresponding to the Greenwald limit, have been obtained in diverted discharges. Limiter H-modes with line averaged electron densities up to 1.7×1020m–3 have been obtained in elongated D-shaped plasmas with 360 kAI
P600 kA.Presented at 17th Symposium Plasma Physics and Technology, Prague, June 13–16, 1995.This work was partly supported by the Fonds National Suisse de la Recherche Scientifique. 相似文献
7.
M.W. Lister 《Thermochimica Acta》1975,11(4):345-355
Equations for the interaction of ions in an ionic crystal, developed earlier1, which allow for the variation of compressibility with pressure, have been applied to calculation of properties connected with the phase transition of potassium chloride under pressure. The data used were only for the high pressure form of the compound. It was found that the calculated transition pressure was much closer to the observed value, if these equations were used; but simpler equations which use a constant compressibility were somewhat better in their calculated values for the lattice energy, molar volume, and change of volume with pressure for the low pressure form of potassium chloride (NaCl structure). It is concluded that, while calculations on these equations form a sensitive test of these equations, the fitting of the equation to the structure needs to be more elaborate. 相似文献
8.
9.
10.
Simon G. Lister Christopher A. Reynolds W. Graham Richards 《International journal of quantum chemistry》1992,41(2):293-310
The electrode potential of 2,3-dicyanobenzoquinone in aqueous solution has been calculated relative to parabenzoquinone using a thermodynamic cycle approach that includes accurate gasphase ab initio calculations and calculation of differences in free energies of hydration using the free-energy perturbation method. The discrepancy between the calculated and experimental electrode potential is disappointingly large (99 mV) compared to previous studies using this approach. This, along with the experimental evidence, suggests that the experimental value itself is too large and that theoretical approaches may indeed be as reliable as experimental ones for determining redox properties of molecules such as 2,3-dicyanobenzoquinone. In the light of this discrepancy we have examined the variation of the results with the basis set, inclusion of electron correlation and changes in the parameters used in the molecular dynamics free-energy simulations. The results are shown to be dependent upon the torsional parameters and especially dependent upon the basis set or semiempirical method used to obtain the electrostatic potential-derived charges. The best charge set was determined using the ab initio criteria of completeness—as far as it can be applied to large molecules—and also by studying the effect of hydration on these charges. This was done by allowing the solvent to perturb the wave function prior to the electrostatic potential determination. Thus, 3-21G and 6-31G * basis sets were found to give satisfactory results. Similar results were obtained using semiempirical and ab initio geometries. 相似文献