全文获取类型
收费全文 | 9506篇 |
免费 | 232篇 |
国内免费 | 32篇 |
专业分类
化学 | 6788篇 |
晶体学 | 61篇 |
力学 | 135篇 |
数学 | 1364篇 |
物理学 | 1422篇 |
出版年
2020年 | 93篇 |
2019年 | 91篇 |
2016年 | 167篇 |
2015年 | 169篇 |
2014年 | 136篇 |
2013年 | 328篇 |
2012年 | 296篇 |
2011年 | 369篇 |
2010年 | 212篇 |
2009年 | 227篇 |
2008年 | 328篇 |
2007年 | 354篇 |
2006年 | 326篇 |
2005年 | 366篇 |
2004年 | 329篇 |
2003年 | 267篇 |
2002年 | 238篇 |
2001年 | 160篇 |
2000年 | 152篇 |
1999年 | 153篇 |
1998年 | 143篇 |
1997年 | 162篇 |
1996年 | 153篇 |
1995年 | 158篇 |
1994年 | 149篇 |
1993年 | 151篇 |
1992年 | 134篇 |
1991年 | 141篇 |
1990年 | 108篇 |
1989年 | 141篇 |
1988年 | 140篇 |
1987年 | 135篇 |
1986年 | 141篇 |
1985年 | 168篇 |
1984年 | 141篇 |
1983年 | 131篇 |
1982年 | 140篇 |
1981年 | 112篇 |
1980年 | 125篇 |
1979年 | 125篇 |
1978年 | 109篇 |
1977年 | 109篇 |
1976年 | 102篇 |
1974年 | 114篇 |
1973年 | 110篇 |
1967年 | 91篇 |
1961年 | 145篇 |
1960年 | 197篇 |
1959年 | 111篇 |
1958年 | 118篇 |
排序方式: 共有9770条查询结果,搜索用时 609 毫秒
981.
Abstract— Oxidation of low-density lipoprotein (LDL) by low amounts of cupric ions resulted in the formation of singlet oxygen (1 O2 , 1 DLg ) when hydroxylamine (NH2OH) was added. Direct evidence on this excited species came from partial spectral resolution of the emitted light in the red spectral region (634 nm and 703 nm), which can be attributed to the dimol decay of singlet oxygen. Additional evidence for the existence of singlet oxygen came from the enhancing effect of deuterium oxide buffer (D20) on chemiluminescence intensity and the quenching effect of sodium azide. A linear correlation between NH2OH-de-pendent chemiluminescence intensity and the amount of diene conjugates (DC) formed in this reaction was observed. Removal of adventitious transition metals by adequate chelators prevented chemiluminescence in this system; NH2OH was also found to efficiently decrease metabolites of lipid peroxidation (LPO). Our findings are consistent with a sequence of reactions in which NH2OH first converts transition metals to their reduced state, thereby stimulating the formation of alkoxy- and peroxy-radicals. Peroxyradicals decompose in a bimolecular Russel reaction to hydroxyl compounds and singlet oxygen while the majority of alkoxy radicals are eliminated by a secondary reaction with NH2OH. Identical effects were observed when reducing antioxidants such as ascorbic acid or trolox C were used instead of hydroxylamine. 相似文献
982.
983.
984.
985.
T. Ludziejewski T. Stöhlker S. Keller H. Beyer F. Bosch O. Brinzanescu C. Kozhuharov A. Krämer D. Liesen P.H. Mokler R.H. Pratt P. Rymuza C.D. Shaffer Z. Stachura P. Świat A. Warczak 《Hyperfine Interactions》1998,114(1-4):165-169
Electron bremsstrahlung has been investigated for collisions of 223.2 MeV/amu He-like uranium ions with N2 and Ar gaseous targets. The doubly differential cross-sections for bremsstrahlung are compared to the predictions of relativistic
first order Born calculations (Bethe-Heitler formula with Elwert correction factor) and to the calculations based on the exact
wavefunctions for electrons moving in the external point-Coulomb potential of the projectile. Whereas the “exact” IPA calculations
give an improved agreement with experimental data, as compared to the Bethe-Heitler theory, in particular at the end-point
region of the bremsstrahlung spectra, discrepancies still remain at lower photon energies.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
986.
987.
988.
989.
Klaus Rissler 《Chromatographia》2005,61(11-12):537-538
990.