全文获取类型
收费全文 | 490篇 |
免费 | 0篇 |
专业分类
化学 | 340篇 |
晶体学 | 44篇 |
力学 | 11篇 |
数学 | 27篇 |
物理学 | 68篇 |
出版年
2021年 | 4篇 |
2019年 | 10篇 |
2018年 | 17篇 |
2017年 | 16篇 |
2016年 | 16篇 |
2015年 | 8篇 |
2014年 | 5篇 |
2013年 | 13篇 |
2012年 | 5篇 |
2011年 | 24篇 |
2010年 | 19篇 |
2009年 | 13篇 |
2008年 | 27篇 |
2007年 | 22篇 |
2006年 | 21篇 |
2005年 | 16篇 |
2004年 | 12篇 |
2003年 | 21篇 |
2002年 | 12篇 |
2001年 | 15篇 |
2000年 | 7篇 |
1999年 | 5篇 |
1998年 | 4篇 |
1997年 | 6篇 |
1995年 | 5篇 |
1992年 | 3篇 |
1991年 | 6篇 |
1990年 | 7篇 |
1989年 | 7篇 |
1988年 | 6篇 |
1987年 | 5篇 |
1986年 | 6篇 |
1984年 | 9篇 |
1983年 | 7篇 |
1982年 | 5篇 |
1981年 | 7篇 |
1980年 | 7篇 |
1979年 | 9篇 |
1978年 | 4篇 |
1977年 | 6篇 |
1976年 | 7篇 |
1975年 | 5篇 |
1974年 | 4篇 |
1973年 | 4篇 |
1972年 | 9篇 |
1971年 | 15篇 |
1970年 | 3篇 |
1969年 | 4篇 |
1968年 | 4篇 |
1966年 | 3篇 |
排序方式: 共有490条查询结果,搜索用时 15 毫秒
1.
2.
O. A. Alekseeva N. I. Sorokina I. A. Verin T. Yu. Losevskaya V. I. Voronkova V. K. Yanovskii V. I. Simonov 《Crystallography Reports》2003,48(2):205-211
This study is a continuation of research into the atomic structure and physical properties of niobium-doped potassium titanyl phosphate crystals, KTiOPO4 (KTP: Nb). Crystals containing 7 and 11 at. % of niobium were grown and studied. With an increase in niobium content, the number of vacancies and additional potassium positions in the structure also increase. This fact accounts for an increase in both the intensities of relaxation peaks and the conductivity of KTP: Nb crystals. 相似文献
3.
Alekseeva E. A. Krasnoshchekaya S. P. Gren' A. I. 《Russian Journal of General Chemistry》2002,72(1):157-159
Russian Journal of General Chemistry - 相似文献
4.
I. S. Kim N. L. Krussanova I. V. Alekseeva R. N. Smartt 《Radiophysics and Quantum Electronics》1998,41(2):94-98
A new approach to investigating the statistical relationship between certain solar features and recurrent wind streams is
presented. This approach is based, on a comparative analysis of the distributions of lifetimes of a set of solar features,
recurrent geomagnetic disturbances, and geomagnetic “calms.” Correlation coefficients of 0.81, 0.85, 0.79, and 0.77 are found
for the distributions of several solar features—filaments, large-scale magnetic fields, coronal features, and coronal holes,
respectively—and recurrent geomagnetic disturbances. A correlation factor of 0.97 between the distributions of geomagnetic
“calms” and active regions is found. The combined evidence indicates that no specific type of solar feature is responsible
for the recurrent stream activity. Rather, the configuration of the large-scale magnetic field of the Sun appears to control
the permanently existing corpuscular activity. Since prominences trace polarity division lines of the large-scale magnetic
field structure of the Sun, they have been checked as a possible general predictor of recurrent corpuscular activity; their
parameters could present the most reliable indices that relate closely with trends in geomagnetic disturbances. A comparative
analysis of cyclic variations of sunspot numbers, the total number of prominences, the relative number of low-height (<-20″)
prominences, and recurrent geomagnetic storms is made for solar cycle N16. The relative number of low-height prominences is
found to correlate broadly (0.83) with recurrent wind streams.
P. K. Shternberg State Astronomical Institute, Moscow, Russia; National Solar Observatory, Sacramento Peak, U.S. Published
in Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 41, No. 2, pp. 145–151, February, 1998. 相似文献
5.
6.
N. I. Mikerova L. M. Alekseeva E. K. Panisheva Yu. N. Sheinker V. G. Granik 《Chemistry of Heterocyclic Compounds》1990,26(3):274-278
The reaction of 2-chloro-5-methylbenzoquinone with -aminocrotonic ester derivatives was studied by PMR spectroscopy in CD3COOD. The spectra indicate the formation of intermediate hydroquinone and quinone derivatives, which subsequently transform into the corresponding indoles. It was shown that the indolization proceeds unequivocally at the 3-position of the initial benzoquinone, and the rate of formation of the indole derivatives decreases with increase in the size of the substituent at the nitrogen atom of the -aminocrotonic ester. The starting, intermediate compounds and the end products observed in the PMR spectra were identified by comparison with specially synthesized compounds.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 324–328, March, 1990. 相似文献
7.
8.
V. M. Lyubchanskaya L. M. Alekseeva V. G. Granik 《Chemistry of Heterocyclic Compounds》1992,28(1):34-39
Previously unknown 3-nitro-6-hydroxyindole derivatives were synthesized by condensation of p-benzoquinone with secondary -nitro enamines.See [1] for Communication 70.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 40–45, January, 1992. 相似文献
9.
Some lessons from the development of metal hydride chemistry in the light of hydrogen storage problems 总被引:1,自引:0,他引:1
O. K. Alekseeva L. N. Padurets P. P. Parshin A. L. Shilov 《Russian Journal of Inorganic Chemistry》2007,52(1):29-33
The main trends of the chemistry of hydrides of transition metals and their alloys are briefly reviewed. “Sensational” hydrogen capacity data and the potential of some metal materials (metals, alloys, and quasi-crystals) and carbon nanomaterials in reversible hydrogen storage applications are critically analyzed. The significance of research in this field for hydrogen energy applications is underlined. 相似文献
10.
A. N. Grinev M. V. Mezentseva E. F. Kuleshova L. M. Alekseeva 《Chemistry of Heterocyclic Compounds》1986,22(5):499-503
The azo coupling of 2,5-diphenylpyrrole with arenediazonium chlorides has given previously unknown 3-arylazopyrroles and 4-phenylazo-3-phenylhydrazono-3H-pyrrole. The methylation and reductive acetylation of the anylazo derivatives have led to N-methylarylazo and acetylamino derivatives of 2,5-diphenylpyrrole. 3-Amino-2, 5-diphenylpyrrole has been obtained by the reduction of 3-p-chlorophenylazo-2,5-diphenylpyrrole. The aminomethylation of 2,5-diphenylpyrrole and its derivatives with bis(dialkylamino)methanes had led to aminomethyl derivatives.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5. pp. 612–615, May, 1986. 相似文献