全文获取类型
收费全文 | 203篇 |
免费 | 4篇 |
国内免费 | 1篇 |
专业分类
化学 | 139篇 |
力学 | 2篇 |
数学 | 46篇 |
物理学 | 21篇 |
出版年
2022年 | 1篇 |
2021年 | 1篇 |
2020年 | 6篇 |
2019年 | 6篇 |
2018年 | 2篇 |
2017年 | 5篇 |
2016年 | 7篇 |
2015年 | 7篇 |
2014年 | 3篇 |
2013年 | 4篇 |
2012年 | 3篇 |
2011年 | 5篇 |
2010年 | 4篇 |
2009年 | 5篇 |
2008年 | 3篇 |
2007年 | 8篇 |
2006年 | 6篇 |
2005年 | 4篇 |
2004年 | 8篇 |
2003年 | 10篇 |
2002年 | 7篇 |
2001年 | 7篇 |
2000年 | 4篇 |
1999年 | 5篇 |
1998年 | 4篇 |
1997年 | 4篇 |
1996年 | 6篇 |
1995年 | 1篇 |
1994年 | 9篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1989年 | 2篇 |
1988年 | 4篇 |
1986年 | 2篇 |
1985年 | 7篇 |
1984年 | 2篇 |
1983年 | 6篇 |
1982年 | 4篇 |
1981年 | 6篇 |
1980年 | 5篇 |
1979年 | 5篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1975年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1969年 | 3篇 |
1967年 | 2篇 |
1906年 | 2篇 |
排序方式: 共有208条查询结果,搜索用时 0 毫秒
81.
82.
Ezio Venturino 《Advances in Computational Mathematics》1994,2(2):223-233
Here, the following lacunary interpolation problem is considered: to find the polynomial which together with its second and
third derivatives agrees on arbitrary points with the corresponding values of a given function. The representation of the
polynomial depends on the solution of a linear algebraic system. The method is constructed on this observation. The error
analysis shows that it behaves like the corresponding Lagrange interpolation problem with an equivalent number of conditions.
Some applications are shown. 相似文献
83.
Ermanno Barni Piero Savarino Guido Viscardi Ezio Pelizzetti 《Journal of heterocyclic chemistry》1983,20(1):23-28
The reaction of 2-(4-methyl-2-pyridyl)benzimidazole with long chain alkyl halides led to N-alkylation at the imidazole ring. The bases obtained were selectively quaternized at the azine and azole nitrogen atoms. The pyridinium salts gave the corresponding polymethyne dyes. Spectral (nmr and uv) and surface properties are briefly discussed. 相似文献
84.
85.
Ezio Stagnaro 《Acta Appl Math》2003,75(1-3):167-181
In this paper, we construct three numerical Burniat surfaces as desingularizations of double planes of degree >10. Two are surfaces having the bigenus P
2=4 and the third is a surface having the bigenus P
2=5. In addition, another surface of general type is constructed as a desingularization of a double plane of degree 12 having the birational invariants: q=p
g
=1, P
2=4. One of the numerical Burniat surfaces with P
2=4 is obtained as a desingularization of a double plane of degree 22 with an irreducible branch locus, so it is a good candidate for having torsion zero. Moreover, its bicanonical transformation seems to be birational. 相似文献
86.
Ermano Barni Piero Savarino Ezio Pelizzetti Guido Rothenberger 《Helvetica chimica acta》1981,64(6):1943-1948
The synthesis, surface activity and micelle formation of three novel cyanine dyes with amphiphilic character is described. It is illustrated by combined surface tension and absorption measurements that in one case self-assembly is highly cooperative leading to aggregates with unique absorption properties. 相似文献
87.
Summary The effect of solvent composition (aqueous mixtures of methanol, ethanol, propan-1-ol and propan-2-ol) on the rate constants and activation parameters of the electron transfer between iron(III) and phenothiazine has been investigated. The dependence of the kinetic parameters on the solvent composition is discussed with reference to previously investigated systems. 相似文献
88.
Ezio Bolzacchini Ruggero Lucini Simone Meinardi Marco Orlandi Bruno Rindone 《Journal of molecular catalysis. A, Chemical》1996,110(3):227-233
Three nitroarenes were submitted to Ru3(CO)12-catalyzed reductive carbonylation in acetonitrile and in cis-cyclooctene. The main reaction products were the corresponding amines, ureas and six- or five-membered cyclization products. Optimization of the reaction varying the temperature, the CO pressure, the catalyst/substrate ratio and the reaction time and a statistical analysis of conversion and selectivity data allow to suggest a reaction mechanism in some reaction conditions. 相似文献
89.
Ermanno Barni Piero Savarino Guido Viscardi Ezio Pelizzetti 《Journal of heterocyclic chemistry》1983,20(1):29-32
The reaction of 2-(4-methyl-2-pyridyl)benzimidazole and of its N long alkyl chain derivatives with 1,3-dibromopropane led to cyclic bis-charged salts. Their spectroscopic (nmr and uv) and surface properties are briefly discussed. It turned out to be interesting to compare the similar behaviour of these salts and the corresponding well known derivatives of 2,2′-bipyridyl. 相似文献
90.
The dissociation equilibria of substituted benzoic acids in cationic and anionic micellar systems, investigated potentiometrically, show pK shifts of less than 1.0 in cationic and 0.5–3 in anionic micelles. Visual titrations of otherwise insoluble acids in cationic micelles give satisfactory results. 相似文献