全文获取类型
收费全文 | 6411篇 |
免费 | 205篇 |
国内免费 | 26篇 |
专业分类
化学 | 4970篇 |
晶体学 | 77篇 |
力学 | 114篇 |
数学 | 501篇 |
物理学 | 980篇 |
出版年
2022年 | 51篇 |
2021年 | 56篇 |
2020年 | 75篇 |
2019年 | 94篇 |
2018年 | 57篇 |
2017年 | 43篇 |
2016年 | 112篇 |
2015年 | 107篇 |
2014年 | 146篇 |
2013年 | 307篇 |
2012年 | 349篇 |
2011年 | 381篇 |
2010年 | 211篇 |
2009年 | 203篇 |
2008年 | 396篇 |
2007年 | 413篇 |
2006年 | 430篇 |
2005年 | 362篇 |
2004年 | 323篇 |
2003年 | 296篇 |
2002年 | 271篇 |
2001年 | 87篇 |
2000年 | 78篇 |
1999年 | 75篇 |
1998年 | 55篇 |
1997年 | 89篇 |
1996年 | 87篇 |
1995年 | 45篇 |
1994年 | 63篇 |
1993年 | 56篇 |
1992年 | 49篇 |
1991年 | 52篇 |
1990年 | 35篇 |
1989年 | 32篇 |
1988年 | 43篇 |
1987年 | 43篇 |
1986年 | 38篇 |
1985年 | 84篇 |
1984年 | 91篇 |
1983年 | 41篇 |
1982年 | 85篇 |
1981年 | 81篇 |
1980年 | 75篇 |
1979年 | 75篇 |
1978年 | 69篇 |
1977年 | 55篇 |
1976年 | 63篇 |
1975年 | 43篇 |
1974年 | 44篇 |
1973年 | 64篇 |
排序方式: 共有6642条查询结果,搜索用时 510 毫秒
921.
Iba S Kato Y Sekitani T Kawaguchi H Sakurai T Someya T 《Analytical and bioanalytical chemistry》2006,384(2):374-377
Inverter circuits have been made by connecting two high-quality pentacene field-effect transistors. A uniform and pinhole-free
900 nm thick polyimide gate-insulating layer was formed on a flexible polyimide film with gold gate electrodes and partially
removed by using a CO2 laser drilling machine to make via holes and contact holes. Subsequent evaporation of the gold layer results in good electrical
connection with a gold gate layer underneath the gate-insulating layer. By optimization of the settings of the CO2 laser drilling machine, contact resistance can be reduced to as low as 3 Ω for 180 μm square electrodes. No degradation of
the transport properties of the organic transistors was observed after the laser-drilling process. This study demonstrates
the feasibility of using the laser drilling process for implementation of organic transistors in integrated circuits on flexible
polymer films. 相似文献
922.
Hong R Fernández JM Nakade H Arvizo R Emrick T Rotello VM 《Chemical communications (Cambridge, England)》2006,(22):2347-2349
Place exchange reactions were studied using dye displacement: subtle changes in ligand structure greatly affected both the rate of displacement and the stability of the monolayer. 相似文献
923.
Imahori H Mitamura K Umeyama T Hosomizu K Matano Y Yoshida K Isoda S 《Chemical communications (Cambridge, England)》2006,(4):406-408
A silica microparticle has been successfully employed as a nanoscaffold to self-organize porphyrin and C60 molecules on a nanostructured SnO2 electrode which exhibits efficient photocurrent generation. 相似文献
924.
Mathew SP Klussmann M Iwamura H Wells DH Armstrong A Blackmond DG 《Chemical communications (Cambridge, England)》2006,(41):4291-4293
Kinetic evidence supports the role of the reaction product in the catalytic cycle of proline-mediated alpha-aminoxylation and alpha-amination reactions, providing both design principles as well as a model for the evolution of efficiency in catalysis. 相似文献
925.
Ito F Ishibashi Y Khan SR Miyasaka H Kameyama K Morisue M Satake A Ogawa K Kobuke Y 《The journal of physical chemistry. A》2006,110(47):12734-12742
Photoinduced electron transfer (ET) and excitation energy transfer (ENT) reactions in monomer and slipped-cofacial dimer systems of a directly linked Zn porphyrin (Por)-Zn phthalocyanine (Pc) heterodyad, ZnPc-ZnPor, were investigated by means of the picosecond and femtosecond transient absorption spectroscopies. In the dimer dyad system of two heterodyads connected through the coordination bond between two imidazolyl-substituted ZnPor bearing ZnPc, ZnPc-ZnPor(D), the rapid ENT from the ZnPor to ZnPc in the subpicosecond time region was followed by photoinduced charge separation (CS) and charge recombination (CR) with time constants of 47 and 510 ps, respectively. On the other hand in the monomer dyad system, no clear charge-separated state was observed although the CS with a time constant of 200 ps and CR with < or =70 ps were estimated. These results indicated that the dimer slipped-cofacial arrangement of pair porphyrins is advantageous for the effective production of the CS state. This advantage was discussed from the viewpoint of a decrease in the reorganization energy of the dimer relative to that of the monomer system. In addition, the electrochemical measurements indicated that the strong interaction between ZnPc and ZnPor moieties also contributed to the fast CS process despite the marginal driving force for the CS process. The dimer dyad of ZnPc-ZnPor provides full advantages in efficiencies of the light harvesting and the CS state production. 相似文献
926.
927.
928.
929.
930.
Yasuyo Maezawa Yoichiroh Hosokawa Kazunori Okano Mie Matsubara Hiroshi Masuhara 《Applied Physics A: Materials Science & Processing》2010,101(1):127-131
When a stress wave generated by focusing a femtosecond laser is loaded on an animal cell adhered on a substrate, the cell
is detached from the substrate. There are two possible mechanisms for the cell detachment: (a) The cell is detached from a
scaffold coated on a glass plate, and (b) the cell is detached from the glass plate with the scaffold. In this work, we have
studied the cell-detachment mechanism by visualizing the scaffold with a fluorescence probe of quantum dots. When the cell
was detached from the substrate, fluorescence from the scaffold simultaneously disappeared from the glass plate, although
the scaffold was not irradiated by the laser. This indicates that detachment due to the stress wave is attributed to mechanism (a).
On the other hand, when the cell was detached from the substrate by a trypsin treatment, the fluorescence from the scaffold
remained, suggesting mechanism (b). By comparing both results, it is considered that physiological damage of the cell membrane
during the detachment process by femtosecond laser-induced stress wave is less than that due to the trypsin treatment. 相似文献