全文获取类型
收费全文 | 185篇 |
免费 | 0篇 |
专业分类
化学 | 85篇 |
晶体学 | 1篇 |
力学 | 11篇 |
数学 | 20篇 |
物理学 | 68篇 |
出版年
2021年 | 3篇 |
2019年 | 2篇 |
2018年 | 2篇 |
2017年 | 5篇 |
2015年 | 2篇 |
2014年 | 6篇 |
2013年 | 9篇 |
2012年 | 10篇 |
2011年 | 8篇 |
2010年 | 7篇 |
2009年 | 8篇 |
2008年 | 6篇 |
2007年 | 8篇 |
2006年 | 8篇 |
2005年 | 7篇 |
2004年 | 1篇 |
2003年 | 3篇 |
2002年 | 1篇 |
2001年 | 1篇 |
2000年 | 4篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1984年 | 4篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1981年 | 4篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1978年 | 3篇 |
1977年 | 4篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1974年 | 7篇 |
1973年 | 5篇 |
1972年 | 3篇 |
1971年 | 2篇 |
1970年 | 7篇 |
1967年 | 5篇 |
1966年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有185条查询结果,搜索用时 15 毫秒
81.
The literature on the reactions of 2-pyridones and their thio analogs with unsaturated compounds taking place by a mechanism of diene synthesis or of substitutive addition, depending on the structure of the initial components, has been systematized. The basic synthetic directions of the use of these reactions and also the stereochemistry of the diene synthesis with 2-pyridones and 2-thiopyridones are considered.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 3–20, January, 1984. 相似文献
82.
Summary From the sum of the cell lipids ofActinomyces No. 660-15 we have isolated a new ornithine-containing lipid the molecule of which is constructed of residues of L- and L--hydroxy fatty acids and L-ornithine.M. M. Shemyakin Institute of the Chemistry of Natural Compounds, Academy of Sciences of the USSR. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 145–153, March–April, 1972. 相似文献
83.
E. I. Filippovich T. N. Pilipenko T. V. Demidkina N. A. Preobrazhenskii 《Chemistry of Heterocyclic Compounds》1970,6(8):972-974
By the condensation of -halogenomethyl derivatives of pyrroles with -unsubstituted pyrroles the synthesis of the following unsymmetrical dipyrrolylmethanes has been effected: 5-benzyloxycarbonyl-5-ethoxycarbonyl-3, 3-di(-methoxycarbonylethyl)-4,4-dimethyl-2,2-dipyrrolylmethane (IIIa), 5-benzyloxycarbonyl-5-ethoxycarbonyl-3-(-methoxycarbonylethyl)-4, 4-diniethyl-3-n-propyl-2,2-dipyrrolylmethane(IIIb), 3-acetyl-5-benzyloxycarbonyl-4-ethyl-5-methoxycarbonyl-3, 4-dimethyl-2,2-dipyrrolylmethane (IIIc), and 3-bromo-5-benzyloxycarbonyl-4-ethyl-5-methoxycarbonyl-3, 4-dimethyl-2,2-dipyrrolylmethane (IIId). Hydrogenation of the unsymmetrical dipyrrolylmethanes IIIa, b, c, and d has given the corresponding monocarboxylic acids IVa, b, c, and d. The formylation of the dipyrrolylmethanemonocarboxylic acid IVa has given 5-ethoxycarbonyl-5-formyl-3,3-di(-methoxycarbonylethyl)-4, 4-dimethyl-2,2-dipyrrolylmethane (V).For communication II, see [1].Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 6, No. 8, pp. 1045–1047, August, 1970. 相似文献
84.
85.
86.
87.
Information is given on the total amino acid composition and the free amino acids of pears (Pyrus communis L), squashes (Cucurbita pepo L), grapefruits (Citrus paradisi L) and apples (Malus sylvestris Mill.). It has been established that during the dispersion of the fruits in the manufacture of sedimentation-stabilized products that the total qualitative and quantitative amino acid compositions scarcely change but the concentration of free amino acids rises by 14.5–45.1% on the total amount of free amino acids in the initial material. The causes of the rise in the level of free amino acids are discussed.Odessa State Academy of Food Technology, fax (0482) 25 32 84. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 234–238, March–April, 1999. 相似文献
88.
O. M. Poltorak E. S. Chukhrai O. S. Pilipenko L. F. Atyaksheva A. E. Beregalov 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2007,81(5):808-812
A comparative study of β-galactosidase amino acid sequences of E. coli and another four out of 11 microorganisms selected at the first stage was performed. It was shown that the functional amino acid residues in the catalytic domain and the ligand environment of the magnesium cation for all five sequences are identical. The mechanism of the catalytic action of E. coli and K. lactis β-galactosidases was investigated by the method of nucleophilic competition. It was shown that the mechanism of the effects of nucleophilic agents is kinetically identical both enzymes: the presence of methanol or butanediols affects the stage of degalactosylation; the presence of magnesium cations promotes the activity of both β-galactosidases; and the mechanisms of the thermal inactivation of E. coli and K. lactis β-galactosidases are different. 相似文献
89.
90.
L. S. Skogareva G. P. Pilipenko I. V. Shabalova T. A. Tripol’skaya 《Russian Journal of Inorganic Chemistry》2011,56(5):673-679
Hydroxyapatite and calcium hydrophosphate peroxo solvates were synthesized and characterized by IR spectroscopy, powder X-ray diffraction, and TGA to be used as biocompatible and antibacterial medicaments in manufacturing calcium phosphate bioceramics for implantations in orthopedics and dentistry. A wide range of hydrogen peroxide percentages in stable mixtures of mCa5(PO4)3(OH) + nCaHPO4 · H2O2 · H2O (ranging from 0.5 to 18%) allows composites to be prepared with a tailored active oxygen content. 相似文献