全文获取类型
收费全文 | 1039篇 |
免费 | 27篇 |
国内免费 | 1篇 |
专业分类
化学 | 720篇 |
晶体学 | 3篇 |
力学 | 19篇 |
数学 | 186篇 |
物理学 | 139篇 |
出版年
2022年 | 11篇 |
2021年 | 10篇 |
2020年 | 10篇 |
2019年 | 15篇 |
2016年 | 18篇 |
2015年 | 18篇 |
2014年 | 26篇 |
2013年 | 39篇 |
2012年 | 52篇 |
2011年 | 41篇 |
2010年 | 28篇 |
2009年 | 27篇 |
2008年 | 45篇 |
2007年 | 45篇 |
2006年 | 46篇 |
2005年 | 40篇 |
2004年 | 58篇 |
2003年 | 41篇 |
2002年 | 34篇 |
2001年 | 13篇 |
2000年 | 20篇 |
1999年 | 14篇 |
1998年 | 12篇 |
1997年 | 18篇 |
1996年 | 19篇 |
1995年 | 24篇 |
1994年 | 12篇 |
1993年 | 16篇 |
1992年 | 11篇 |
1991年 | 16篇 |
1990年 | 7篇 |
1989年 | 7篇 |
1988年 | 10篇 |
1987年 | 19篇 |
1986年 | 11篇 |
1985年 | 12篇 |
1984年 | 14篇 |
1983年 | 16篇 |
1982年 | 17篇 |
1981年 | 9篇 |
1980年 | 13篇 |
1979年 | 15篇 |
1978年 | 13篇 |
1977年 | 15篇 |
1976年 | 9篇 |
1975年 | 10篇 |
1973年 | 17篇 |
1972年 | 10篇 |
1971年 | 7篇 |
1931年 | 7篇 |
排序方式: 共有1067条查询结果,搜索用时 31 毫秒
101.
Application of the Tris(acetylacetonato)iron(III)/(II) Redox Couple in p‐Type Dye‐Sensitized Solar Cells
下载免费PDF全文
![点击此处可从《Angewandte Chemie (International ed. in English)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Ishanie Rangeeka Perera Dr. Torben Daeneke Satoshi Makuta Dr. Ze Yu Prof. Dr. Yasuhiro Tachibana Dr. Amaresh Mishra Prof. Dr. Peter Bäuerle Dr. C. André Ohlin Prof. Dr. Udo Bach Prof. Dr. Leone Spiccia 《Angewandte Chemie (International ed. in English)》2015,54(12):3758-3762
An electrolyte based on the tris(acetylacetonato)iron(III)/(II) redox couple ([Fe(acac)3]0/1?) was developed for p‐type dye‐sensitized solar cells (DSSCs). Introduction of a NiO blocking layer on the working electrode and the use of chenodeoxycholic acid in the electrolyte enhanced device performance by improving the photocurrent. Devices containing [Fe(acac)3]0/1? and a perylene–thiophene–triphenylamine sensitizer (PMI–6T–TPA) have the highest reported short‐circuit current (JSC=7.65 mA cm?2), and energy conversion efficiency (2.51 %) for p‐type DSSCs coupled with a fill factor of 0.51 and an open‐circuit voltage VOC=645 mV. Measurement of the kinetics of dye regeneration by the redox mediator revealed that the process is diffusion limited as the dye‐regeneration rate constant (1.7×108 M ?1 s?1) is very close to the maximum theoretical rate constant of 3.3×108 M ?1 s?1. Consequently, a very high dye‐regeneration yield (>99 %) could be calculated for these devices. 相似文献
102.
Dali Wang Chunlai Tu Yue Su Chuan Zhang Udo Greiser Xinyuan Zhu Deyue Yan Wenxin Wang 《Chemical science》2015,6(7):3775-3787
Despite of great advances of phospholipids and liposomes in clinical therapy, very limited success has been achieved in the preparation of smart phospholipids and controlled-release liposomes for in vivo drug delivery and clinical trials. Here we report a supramolecular approach to synthesize novel supramolecularly engineered phospholipids based on complementary hydrogen bonding of nucleosides, which greatly reduces the need of tedious chemical synthesis, including reducing the strict requirements for multistep chemical reactions, and the purification of the intermediates and the amount of waste generated relative more traditional approaches. These upgraded phospholipids self-assemble into liposome-like bilayer structures in aqueous solution, exhibiting fast stimuli-responsive ability due to the hydrogen bonding connection. In vitro and in vivo evaluations show the resulted supramolecular liposomes from nucleoside phospholipids could effectively transport drug into tumor tissue, rapidly enter tumor cells, and controllably release their payload in response to an intracellular acidic environment, thus resulting in a much higher antitumor activity than conventional liposomes. The present supramolecularly engineered phospholipids represent an important evolution in comparison to conventional covalent-bonded phospholipid systems. 相似文献
103.
A homogenization framework for the stochastic average meso-scale tread-road interaction with emphasis on macro-scale rolling resistance calculations is presented in this contribution. This framework accounts for large scale, high-frequency penetration of tread rubber by the highest asperities as well as for the nonlinear thermo-viscoelastic material behavior of this tread rubber in the regime of finite strains. (© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
104.
Kwon TH Armel V Nattestad A Macfarlane DR Bach U Lind SJ Gordon KC Tang W Jones DJ Holmes AB 《The Journal of organic chemistry》2011,76(10):4088-4093
A one-pot synthesis of 2,6-dibromodithieno[3,2-b;2',3'-d]thiophene (dibromo-DTT, 4) was developed. A key step was bromodecarboxylation of DTT-2,6-dicarboxylic acid, obtained by saponification of the diester 1. The donor-acceptor dye DAHTDTT (13), based on a central 2,6-bis[2'-(3'-hexylthienyl)]dithieno[3,2-b;2',3'-d]thiophene core (9), was prepared and incorporated in a dye-sensitized solar cell (DSC), which exhibited an energy conversion efficiency of 7.3% with V(oc) of 697 mV, J(sc) of 14.4 mA/cm(2), and ff of 0.73 at 1 sun. 相似文献
105.
For representations of tame quivers the degenerations are controlled by the dimensions of various homomorphism spaces. Furthermore, there is no proper degeneration to an indecomposable. Therefore, up to common direct summands, any minimal degeneration from M to N is induced by a short exact sequence 0→U→M→V→0 with indecomposable ends that add up to N. We study these ‘building blocs’ of degenerations and we prove that the codimensions are bounded by two. Therefore, a quiver is Dynkin resp. Euclidean resp. wild iff the codimension of the building blocs is one resp. bounded by two resp. unbounded. We explain also that for tame quivers the complete classification of all the building blocs is a finite problem that can be solved with the help of a computer. 相似文献
106.
107.
108.
109.
110.