全文获取类型
收费全文 | 1348625篇 |
免费 | 38523篇 |
国内免费 | 14716篇 |
专业分类
化学 | 675891篇 |
晶体学 | 14582篇 |
力学 | 77742篇 |
综合类 | 666篇 |
数学 | 246664篇 |
物理学 | 386319篇 |
出版年
2021年 | 14426篇 |
2020年 | 17746篇 |
2019年 | 18040篇 |
2018年 | 13908篇 |
2016年 | 29898篇 |
2015年 | 23092篇 |
2014年 | 33319篇 |
2013年 | 78288篇 |
2012年 | 42527篇 |
2011年 | 39317篇 |
2010年 | 40240篇 |
2009年 | 42699篇 |
2008年 | 37099篇 |
2007年 | 32359篇 |
2006年 | 38608篇 |
2005年 | 30540篇 |
2004年 | 31255篇 |
2003年 | 29189篇 |
2002年 | 27163篇 |
2001年 | 26870篇 |
2000年 | 23038篇 |
1999年 | 21073篇 |
1998年 | 19708篇 |
1997年 | 20188篇 |
1996年 | 20137篇 |
1995年 | 19436篇 |
1994年 | 18899篇 |
1993年 | 18297篇 |
1992年 | 17964篇 |
1991年 | 18167篇 |
1990年 | 17300篇 |
1989年 | 17258篇 |
1988年 | 16743篇 |
1987年 | 16757篇 |
1986年 | 15661篇 |
1985年 | 22187篇 |
1984年 | 23444篇 |
1983年 | 19551篇 |
1982年 | 21288篇 |
1981年 | 20459篇 |
1980年 | 19772篇 |
1979年 | 19955篇 |
1978年 | 21338篇 |
1977年 | 20960篇 |
1976年 | 20718篇 |
1975年 | 19370篇 |
1974年 | 19017篇 |
1973年 | 19550篇 |
1972年 | 14081篇 |
1967年 | 12446篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
Kislitsin A. A. Drachuk A. O. Molokitina N. S. Podenko L. S. 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2020,94(2):405-411
Russian Journal of Physical Chemistry A - The kinetics of methane hydrate formation in “dry water” is studied using a diffusion model (the well-known modified shrinking core model). An... 相似文献
993.
994.
Mathematical Notes - For the monotone symmetric threshold Boolean functions $$ f^n_2(\widetilde x\mspace{2mu})=\bigvee_{1\le i 相似文献
995.
Doklady Mathematics - In this paper we extend Y. Eliashberg’s theorem on the maps with fold type singularities to arbitrary Thom-Boardman singularities. Namely, we state a necessary and... 相似文献
996.
Doklady Mathematics - This paper shows the integrability of certain classes of odd-order dynamical systems that are homogeneous with respect to some of the variables and in which a system on the... 相似文献
997.
N. Stallkamp S. Ringleb B. Arndt M. Kiffer S. Kumar T. Morgenroth G.G. Paulus W. Quint Th. Stöhlker M. Vogel 《X射线光谱测定》2020,49(1):188-191
Detailed investigations of laser–ion interactions require well-defined ion targets and detection techniques for high-sensitivity measurements of reaction educts and products. To this end, we have designed and built the High-Intensity Laser-Ion Trap Experiment Penning trap setup, which features various ion-target preparation techniques including selection, cooling, compression, and positioning as well as destructive and non-destructive measurement techniques to determine the number of stored ions for all charge states individually and simultaneously. We have recently performed first commissioning experiments of ion deceleration and dynamic ion capture with highly charged ion bunches from an electron beam ion source. We have characterized our single-pass non-destructive ion counter in detail and were able to determine the ion velocity as well as the number of ions from the signals acquired. 相似文献
998.
Morgunov R. B. Bezverkhnii A. I. Dmitriev O. S. Bakhmet’ev M. V. 《Physics of the Solid State》2020,62(3):458-463
Physics of the Solid State - It has been established that nonmonotonic magnetization relaxation in Pt/Co/Ir/Co/Pt synthetic ferrimagnets (SF) with perpendicular magnetic anisotropy is caused by the... 相似文献
999.
Kamzin A. S. Valiullin A. A. Bingolbali A. Doǧan N. 《Physics of the Solid State》2020,62(7):1231-1239
Physics of the Solid State - Changes in the structure and properties of the Ni1 – xCuxFe2O4 ferrites-spinel magnetic nanoparticles depending on the Cu ion concentration (0... 相似文献
1000.
Hctor Solís-Chagoyn Aline Domínguez-Alonso Marcela Valds-Tovar Jesús Argueta Zuly A. Snchez-Florentino Eduardo Calixto Gloria Benítez-King 《Molecules (Basel, Switzerland)》2020,25(23)
The pro-oxidant compound okadaic acid (OKA) mimics alterations found in Alzheimer’s disease (AD) as oxidative stress and tau hyperphosphorylation, leading to neurodegeneration and cognitive decline. Although loss of dendrite complexity occurs in AD, the study of this post-synaptic domain in chemical-induced models remains unexplored. Moreover, there is a growing expectation for therapeutic adjuvants to counteract these brain dysfunctions. Melatonin, a free-radical scavenger, inhibits tau hyperphosphorylation, modulates phosphatases, and strengthens dendritic arbors. Thus, we determined if OKA alters the dendritic arbors of hilar hippocampal neurons and whether melatonin prevents, counteracts, or reverses these damages. Rat organotypic cultures were incubated with vehicle, OKA, melatonin, and combined treatments with melatonin either before, simultaneously, or after OKA. DNA breaks were assessed by TUNEL assay and nuclei were counterstained with DAPI. Additionally, MAP2 was immunostained to assess the dendritic arbor properties by the Sholl method. In hippocampal hilus, OKA increased DNA fragmentation and reduced the number of MAP2(+) cells, whereas melatonin protected against oxidation and apoptosis. Additionally, OKA decreased the dendritic arbor complexity and melatonin not only counteracted, but also prevented and reversed the dendritic arbor retraction, highlighting its role in post-synaptic domain integrity preservation against neurodegenerative events in hippocampal neurons. 相似文献