全文获取类型
收费全文 | 3814篇 |
免费 | 115篇 |
国内免费 | 20篇 |
专业分类
化学 | 2849篇 |
晶体学 | 62篇 |
力学 | 36篇 |
数学 | 161篇 |
物理学 | 841篇 |
出版年
2023年 | 15篇 |
2022年 | 28篇 |
2021年 | 33篇 |
2020年 | 38篇 |
2019年 | 36篇 |
2018年 | 35篇 |
2017年 | 27篇 |
2016年 | 69篇 |
2015年 | 70篇 |
2014年 | 73篇 |
2013年 | 185篇 |
2012年 | 216篇 |
2011年 | 229篇 |
2010年 | 149篇 |
2009年 | 147篇 |
2008年 | 210篇 |
2007年 | 243篇 |
2006年 | 247篇 |
2005年 | 263篇 |
2004年 | 187篇 |
2003年 | 204篇 |
2002年 | 175篇 |
2001年 | 65篇 |
2000年 | 56篇 |
1999年 | 60篇 |
1998年 | 27篇 |
1997年 | 42篇 |
1996年 | 55篇 |
1995年 | 21篇 |
1994年 | 24篇 |
1993年 | 26篇 |
1992年 | 44篇 |
1991年 | 31篇 |
1990年 | 31篇 |
1989年 | 27篇 |
1988年 | 20篇 |
1987年 | 18篇 |
1986年 | 28篇 |
1985年 | 59篇 |
1984年 | 60篇 |
1983年 | 19篇 |
1982年 | 51篇 |
1981年 | 50篇 |
1980年 | 47篇 |
1979年 | 37篇 |
1978年 | 29篇 |
1977年 | 25篇 |
1976年 | 22篇 |
1975年 | 18篇 |
1974年 | 16篇 |
排序方式: 共有3949条查询结果,搜索用时 15 毫秒
51.
52.
Yatsuhisa Nagano Yuhji Achiba Kenji Sato Katsumi Kimura 《Chemical physics letters》1982,93(5):510-514
Kenetic energies and angular distributions of photoelectrons emitted by three-photon ionization fo atomic iron through two-photon resonant state e7DJ and e5 DJ, were measured, by using visible lasers. J-resolved photoelectron bands attributab to the a6DJ and a4Fj ionic states are reported. 相似文献
53.
Tadayuki Hara Jitsuro Sugie 《NoDEA : Nonlinear Differential Equations and Applications》1995,2(4):527-551
In this paper we study the problem whether all trajectories of the system
=y–F(x) and
=–g(x) cross the vertical isocline which is very important for the existence of periodic solutions and oscillation theory. The problem has not been solved for the critical case:
相似文献
54.
Isao Watanabe Kusuo Nishiyama Kanetada Nagamine Kenji Kawano Ken-ichi Kumagai 《Hyperfine Interactions》1994,86(1):603-608
Zero field positive muon spin rotation method (
+SR) is applied on La2–x
Sr
x
CuO4 around forx=0.12 at which the high-T
c
superconductivity (SC) is suppressed. The magnetically ordered state of Cu-moments, which is not a spin glass state but an antiferromagnetic like state, appears below 15 K for 0.105x0.120. The magnetic phase boundary is very similar to the one of the La2–x
Ba
x
CuO4 in which the structural transition from the low temperature orthorhombic (LTO) phase to the low temperature tetragonal (LTT) phase is observed aroundx=0.12. The present study suggests that there is no big difference of the electronic state of the CuO2 plane between the La-Ba system and the La-Sr system and that the magnetic ordering of Cu-moments plays an important role for the suppression of the high-T
c
SC aroundx=0.12 in both of the systems, although the LTO-LTT structural transition has not been observed yet in the La-Sr system. 相似文献
55.
A novel electron spin echo method employing detection of FID and transient echo shape following selective hole burning in the EPR spectrum has been applied to study γ-irradiated malonic acid. The dipolar lineshapes of stabilized free radicals are separated into bulk and pairwise contributions; both of them have proved to be Lorentzian. 相似文献
56.
57.
Kenji Kojima Kusuo Nishiyama Kanetada Nagamine Hironobu Ikeda 《Hyperfine Interactions》1993,78(1-4):429-433
The site diluted finite spin cluster system Rb2CO
x
Mg1–x
F4 (x=0.15, 0.4, 0.5) has been investigated by the +SR technique. Muon spin relaxation was observed in these diluted magnetic systems in a weak longitudinal field of 100 G. By reducing temperature below 100 K, the experimental data show features of slowing down phenomena of the Co electron moments in the finite spin clusters. 相似文献
58.
4-Fluorinated UDP-MurNAc pentapeptide, 2, has been synthesized. In our previous study, UDP-MurNAc pentapeptide analogue 1 was found to be incorporated into the bacterial cell wall through biosynthesis. Compound 2 showed growth-inhibition activity against Gram-positive bacteria when it was added to growth media at 0.01 mg/mL. [structure--see text] 相似文献
59.
Palladium compounds and metallic palladium combined with phosphine are active catalysts of selective hydrosilylation of terminal olefins. Butadiene and trichlorosilane give a 1:1 adduct and trimethylsilane affords a 1:2 adduct. Special features of the palladium catalyzed hydrosilylation reactions are presented. 相似文献
60.
|