全文获取类型
收费全文 | 308742篇 |
免费 | 2019篇 |
国内免费 | 675篇 |
专业分类
化学 | 149321篇 |
晶体学 | 4039篇 |
力学 | 15228篇 |
综合类 | 6篇 |
数学 | 46902篇 |
物理学 | 95940篇 |
出版年
2021年 | 1880篇 |
2020年 | 2072篇 |
2019年 | 2368篇 |
2018年 | 11029篇 |
2017年 | 11761篇 |
2016年 | 8141篇 |
2015年 | 3279篇 |
2014年 | 4141篇 |
2013年 | 9736篇 |
2012年 | 11265篇 |
2011年 | 20299篇 |
2010年 | 12784篇 |
2009年 | 12794篇 |
2008年 | 18209篇 |
2007年 | 21524篇 |
2006年 | 8158篇 |
2005年 | 13240篇 |
2004年 | 9524篇 |
2003年 | 9097篇 |
2002年 | 7053篇 |
2001年 | 6246篇 |
2000年 | 5095篇 |
1999年 | 3598篇 |
1998年 | 3106篇 |
1997年 | 3079篇 |
1996年 | 3036篇 |
1995年 | 2478篇 |
1994年 | 2537篇 |
1993年 | 2564篇 |
1992年 | 2694篇 |
1991年 | 2682篇 |
1990年 | 2603篇 |
1989年 | 2573篇 |
1988年 | 2512篇 |
1987年 | 2496篇 |
1986年 | 2382篇 |
1985年 | 3092篇 |
1984年 | 3260篇 |
1983年 | 2605篇 |
1982年 | 2877篇 |
1981年 | 2765篇 |
1980年 | 2565篇 |
1979年 | 2797篇 |
1978年 | 2921篇 |
1977年 | 2868篇 |
1976年 | 2865篇 |
1975年 | 2713篇 |
1974年 | 2689篇 |
1973年 | 2878篇 |
1972年 | 1887篇 |
排序方式: 共有10000条查询结果,搜索用时 171 毫秒
21.
Crystallography Reports - Methods of coherent X-ray diffraction imaging of the spatial structure of noncrystalline objects and nanocrystals (nanostructures) are considered. Particular attention is... 相似文献
22.
Komarova E. G. Sedelnikova M. B. Kazantseva E. A. Uvarkin P. V. Sharkeev Yu. P. 《Russian Physics Journal》2020,63(7):1249-1256
Russian Physics Journal - A relationship between the structural-morphological and physical-mechanical properties of macro-porous calcium phosphate (CaP) coatings on the surface of titanium implants... 相似文献
23.
Kang Il Yoo Ji Yeong Jeon Su Jeong Ryu Giri Nam Hyewon Youn Eun Young Choi 《Experimental & molecular medicine》2015,47(2):e140
In allogeneic transplantation, including the B6 anti-BALB.B settings, H60 and H4 are two representative dominant minor histocompatibility antigens that induce strong CD8 T-cell responses. With different distribution patterns, H60 expression is restricted to hematopoietic cells, whereas H4 is ubiquitously expressed. H60-specific CD8 T-cell response has been known to be dominant in most cases of B6 anti-BALB.B allo-responses, except in the case of skin transplantation. To understand the mechanism underlying the subdominance of H60 during allogeneic skin transplantation, we investigated the dynamics of the H60-specific CD8 T cells in B6 mice transplanted with allogeneic BALB.B tail skin. Unexpectedly, longitudinal bioluminescence imaging and flow cytometric analyses revealed that H60-specific CD8 T cells were not always subdominant to H4-specific cells but instead showed a brief dominance before the H4 response became predominant. H60-specific CD8 T cells could expand in the draining lymph node and migrate to the BALB.B allografts, indicating their active participation in the anti-BALB.B allo-response. Enhancing the frequencies of H60-reactive CD8 T cells prior to skin transplantation reversed the immune hierarchy between H60 and H4. Additionally, H60 became predominant when antigen presentation was limited to the direct pathway. However, when antigen presentation was restricted to the indirect pathway, the expansion of H60-specific CD8 T cells was limited, whereas H4-specific CD8 T cells expanded significantly, suggesting that the temporary immunodominance and eventual subdominance of H60 could be due to their reliance on the direct antigen presentation pathway. These results enhance our understanding of the immunodominance phenomenon following allogeneic tissue transplantation. 相似文献
24.
Kazakova E. F. Dmitrieva N. E. Zvereva N. L. 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2020,94(2):341-344
Russian Journal of Physical Chemistry A - Rapidly quenched alloys of aluminum with cobalt and zirconium are investigated using a combination of means of physicochemical analysis to study the... 相似文献
25.
K. E. Prikhodko M. M. Dementyeva B. A. Gurovich D. A. Komarov L. V. Kutuzov 《Crystallography Reports》2018,63(2):241-244
The change in the free-electron density in ultrathin (5 nm) superconducting NbN films in the initial state and after irradiation by O+ ions to doses of (0.1–0.9) × 1017 cm–2 has been studied by electron energy-loss spectroscopy (EELS). The analysis has been performed on cross section samples prepared by the focused ion beam method, using plasmon oscillations with energies up to 50 eV. The radiation-induced replacement of nitrogen atoms with oxygen atoms in niobium nitride is found to change the electrical properties of the material, which leads to a decrease in the free-electron density with an increase in the irradiation dose. 相似文献
26.
Complex Study of the Spearhead Superficial Crust from Burial Mound no. 1 near Novosvobodnaya Village
Loboda A. Yu. Kolobylina N. N. Veligzhanin A. A. Zubavitchus Y. V. Tereshchenko E. Yu. Shishlina N. I. Yatsishina E. B. Kashkarov P. K. 《Crystallography Reports》2018,63(2):295-301
A complex study of a spearhead dated back to IV mill. BC from burial mound no. 1 near Novosvobodnaya village (collection of the State Historical Museum) and, in particular, the material of spearhead superficial crust has been performed. The elemental and phase composition of the metal of spearhead and the superficial crust on its surface have been determined by scanning electron microscopy, jointly with energydispersive X-ray microanalysis and X-ray phase analysis. A comparative analysis of the results of studying the spearhead superficial crust and similar crusts on other artifacts from the mounds near Novosvobodnaya village suggest natural origin of the crust on copper?arsenic artifacts.
相似文献27.
28.
29.
30.