全文获取类型
收费全文 | 364篇 |
免费 | 17篇 |
国内免费 | 1篇 |
专业分类
化学 | 249篇 |
晶体学 | 2篇 |
力学 | 28篇 |
数学 | 72篇 |
物理学 | 31篇 |
出版年
2022年 | 9篇 |
2021年 | 17篇 |
2020年 | 12篇 |
2019年 | 10篇 |
2018年 | 7篇 |
2017年 | 9篇 |
2016年 | 18篇 |
2015年 | 13篇 |
2014年 | 8篇 |
2013年 | 19篇 |
2012年 | 24篇 |
2011年 | 28篇 |
2010年 | 12篇 |
2009年 | 13篇 |
2008年 | 19篇 |
2007年 | 14篇 |
2006年 | 22篇 |
2005年 | 13篇 |
2004年 | 7篇 |
2003年 | 9篇 |
2002年 | 9篇 |
2001年 | 6篇 |
2000年 | 5篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1993年 | 10篇 |
1992年 | 7篇 |
1991年 | 5篇 |
1989年 | 4篇 |
1987年 | 2篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1974年 | 4篇 |
1973年 | 3篇 |
1972年 | 3篇 |
1970年 | 3篇 |
1969年 | 2篇 |
1968年 | 1篇 |
1967年 | 2篇 |
1965年 | 2篇 |
排序方式: 共有382条查询结果,搜索用时 15 毫秒
1.
Danilov Felix I. Bogdanov Dmytro A. Smyrnova Olena V. Korniy Sergiy A. Protsenko Vyacheslav S. 《Journal of Solid State Electrochemistry》2022,26(4):939-957
Journal of Solid State Electrochemistry - The electrochemical deposition of a nickel–iron alloy from a plating solution based on a deep eutectic solvent (a eutectic mixture of ethylene glycol... 相似文献
2.
Chemical versus Electrochemical Synthesis of Carbon Nano‐onion/Polypyrrole Composites for Supercapacitor Electrodes
下载免费PDF全文
![点击此处可从《Chemistry (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Olena Mykhailiv Monika Imierska Martyna Petelczyc Prof. Dr. Luis Echegoyen Dr. Marta E. Plonska‐Brzezinska 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(15):5783-5793
The development of high‐surface‐area carbon electrodes with a defined pore size distribution and the incorporation of pseudo‐active materials to optimize the overall capacitance and conductivity without destroying the stability are at present important research areas. Composite electrodes of carbon nano‐onions (CNOs) and polypyrrole (Ppy) were fabricated to improve the specific capacitance of a supercapacitor. The carbon nanostructures were uniformly coated with Ppy by chemical polymerization or by electrochemical potentiostatic deposition to form homogenous composites or bilayers. The materials were characterized by transmission‐ and scanning electron microscopy, differential thermogravimetric analyses, FTIR spectroscopy, piezoelectric microgravimetry, and cyclic voltammetry. The composites show higher mechanical and electrochemical stabilities, with high specific capacitances of up to about 800 F g?1 for the CNOs/SDS/Ppy composites (chemical synthesis) and about 1300 F g?1 for the CNOs/Ppy bilayer (electrochemical deposition). 相似文献
3.
Avramenko Andriy A. Shevchuk Igor V. Dmitrenko Nataliia P. Skitsko Ivan F. 《Journal of Thermal Analysis and Calorimetry》2022,147(22):12709-12719
Journal of Thermal Analysis and Calorimetry - The paper focuses on the analytical analysis of the propagation of a normal shock wave in an adiabatic gas flow with nanoparticles. A modified... 相似文献
4.
Petro P Onys'ko Olena A SuvalovaYuliya V Rassukana Tetyana I ChudakovaAnatolii D Sinitsa 《Tetrahedron letters》2003,44(9):1855-1857
The reaction of alkyl trifluoro(organylsulfonylimino)propionates with phosphites occurs with NC transfer of the RSO2 group and leads to sulfonyl-substituted trifluoroalanine derivatives. The novel rearrangement is interpreted as cheletropic 1,4-cycloaddition of the phosphite and subsequent 1,2-shift of the sulfonyl group in the intermediate cyclic phosphorane. 相似文献
5.
The photoconductivity and electrical conductivity, the thermally stimulated polarization and depolarization currents, the
permittivity, and the dielectric losses of noncentrosymmetric Ca3Ga2Ge4O14 crystals of a structural type of trigonal calcium gallogermanate (CGG) have been studied for the first time in the temperature
interval 100–700 K in air and in vacuum. The features of the temperature behavior of CGG are associated, in particular, with
the effect of electrically active defects and partial disordering of the cation sublattice of the crystal structure, which
generates polar formations (dipoles) of several kinds. Certain parameters of the electromigration and of the electrically
active defects that cause charge-relaxation and polarization effects are determined. It is concluded that dipole relaxation
in CGG makes it a new representative of a class of materials in which reorientation of the dipoles as a system of mobile local
distortions of the structure has a substantial effect on the physical properties.
Fiz. Tverd. Tela (St. Petersburg) 39, 871–876 (May 1997) 相似文献
6.
F. A. Mikhailenko L. I. Shevchuk V. S. Tolmacheva F. S. Babichev 《Chemistry of Heterocyclic Compounds》1982,18(7):723-727
2,3,3-Trimethyl-3H-pyrrolo[3,2-c]quinoline and its 8-methoxy derivative were obtained from methyl isopropyl ketone 4-quinolylhydrazones. These bases form quaternary salts at the azine nitrogen atom, from which polymethine dyes were obtained. The changes in the absorption spectra of the dyes in solutions with various acidities were examined.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 948–951, July, 1982. 相似文献
7.
Two furofuranoid lignan glycosides, having the structures of (+)-syringaresinol 4′,4″-di-β-D-glucopyranoside (1) and (+)-syringaresinol 4′-β-D-glucopyranoside (2), and also 2-methylbut-3-en-2-yl β-D-glucopyranoside (3), have been isolated from an extract of the leaves ofNolina microcarpa (fam. Dracaenaceae). 相似文献
8.
V.A. Ozeryanskii A.F. Pozharskii D.A. Shevchuk A.N. Chekhlov O.A. Dyachenko 《Tetrahedron》2005,61(17):4221-4232
A simple procedure for the synthesis of N,N,N′-trialkyl-1,8-diaminonaphthalenes is described. It consists in partial demethylation (dealkylation) of commercially available proton sponge [1,8-bis(dimethylamino)naphthalene] and some of its derivatives at heating with HBr-KI-DMF system. Limitation, scope and a possible mechanistic pathway for the reaction are discussed. For isomeric 8-dimethylamino-1-methylamino- and 1-dimethylamino-8-methylamino-4-nitronaphthalenes, X-ray measurements have been conducted. The first examples of complete realkylation reactions in the naphthalene proton sponges are reported. 相似文献
9.
G. V. Shevchuk Yu. S. Vollerner A. S. Shashkov M. B. Gorovits V. Ya. Chirva 《Chemistry of Natural Compounds》1991,27(6):706-711
Two new glycosides which have been called nolinofurosides G(I) and H(III), have been isolated from the leaves ofNolina microcarpa. Nolinofuroside G is the sodium salt of 26-β-D-glucofuranosyloxy-(25S)-furost-5,20(22)-diene-1β, 3β-diol 1-sulfate, and nolinofuroside
H is the sodium salt of 1-β-D-fucopyranosyloxy-26-β-D-glucopyranosyloxy-(25S)-furost-5,20(22)-dinen-1β-3β-ol 3-sulfate.
M. V. Frunze Simferopol' State University. Institute of the Chemistry of Plant Substances, Uzbek. Academy of Sciences, Tashkent.
Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 801–806, November–December, 1991. 相似文献
10.
Iodination of arenes was carried out by reacting 1 equiv of arene substrate with 0.5 equiv of iodine under an oxygen atmosphere with H5PV2Mo10O40 as oxidation catalyst. The synthesis is an inherently waste-free method for the preparation of iodoarenes. 相似文献