全文获取类型
收费全文 | 83篇 |
免费 | 1篇 |
专业分类
化学 | 37篇 |
力学 | 3篇 |
数学 | 20篇 |
物理学 | 24篇 |
出版年
2021年 | 1篇 |
2014年 | 2篇 |
2013年 | 2篇 |
2012年 | 1篇 |
2011年 | 8篇 |
2010年 | 1篇 |
2009年 | 4篇 |
2008年 | 5篇 |
2007年 | 7篇 |
2006年 | 3篇 |
2005年 | 2篇 |
2004年 | 5篇 |
2003年 | 2篇 |
2002年 | 1篇 |
2001年 | 1篇 |
2000年 | 4篇 |
1998年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1990年 | 1篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 5篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1972年 | 1篇 |
1935年 | 2篇 |
1932年 | 1篇 |
排序方式: 共有84条查询结果,搜索用时 218 毫秒
81.
Silvestri F Jordan M Howes K Kivala M Rivera-Fuentes P Boudon C Gisselbrecht JP Schweizer WB Seiler P Chiu M Diederich F 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(22):6088-6097
The substrate scope of the [2+2] cycloaddition-cycloreversion (CA-CR) reaction between electron-deficient (2,2-dicyanovinyl)benzene (DCVB) or (1,2,2-tricyanovinyl)benzene (TCVB) derivatives and N,N-dimethylanilino (DMA)-substituted acetylenes was investigated. The structural features of the cyanobutadiene products of these transformations were examined and the rates of selected CA-CR reactions were measured. Rate constants for reactions utilizing pentafluorinated TCVB and DCVB were found to be one to two orders of magnitude larger than those for the unsubstituted analogues. Multiple, consecutive CA-CR reactions were performed with substrates incorporating two reactive 2,2-cyanovinyl or 4-ethynylanilino sites. 1,4-Bis(2,2-dicyanovinyl)-2,3,5,6-tetrafluorobenzene and 1,4-bis[(4'-dihexylamino)phenylethynyl]benzene were selected as suitably reactive monomers for the synthesis of regular [AB] oligomers wherein the push-pull chromophores were formed in the chain-growth step. Oligomers of two types were isolated: macrocyclic [AB](n) and open-chain B[AB](n) oligomers, with n≤4. 相似文献
82.
Dr. Kara Howes Dr. Abdelhalim Belbakra Dr. Andrea Listorti Dr. W. Bernd Schweizer Dr. Philippe Reutenauer Dr. José‐Lorenzo Alonso‐Gómez Dr. Claudio Chiorboli Lorenz M. Urner Dr. Jean‐Paul Gisselbrecht Prof. Dr. Corinne Boudon Dr. Nicola Armaroli Prof. Dr. François Diederich 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(1):202-216
The synthesis, electrochemical, and photophysical properties of five multicomponent systems featuring a ZnII porphyrin (ZnP) linked to one or two anilino donor‐substituted pentacyano‐ (PCBD) or tetracyanobuta‐1,3‐dienes (TCBD), with and without an interchromophoric bridging spacer (S), are reported: ZnP‐S‐PCBD ( 1 ), ZnP‐S‐TCBD ( 2 ), ZnP‐TCBD ( 3 ), ZnP‐(S‐PCBD)2 ( 4 ), and ZnP‐(S‐TCBD)2 ( 5 ). By means of steady‐state and time‐resolved absorption and luminescence spectroscopy (RT and 77 K), photoinduced intramolecular energy and electron transfer processes are evidenced, upon excitation of the porphyrin unit. In systems equipped with the strongest acceptor PCBD and the spacer ( 1 , 4 ), no evidence of electron transfer is found in toluene, suggesting ZnP→PCBD energy transfer, followed by ultrafast (<10 ps) intrinsic deactivation of the PCBD moiety. In the analogous systems with the weaker acceptor TCBD ( 2 , 5 ), photoinduced electron transfer occurs in benzonitrile, generating a charge‐separated (CS) state lasting 2.3 μs. Such a long lifetime, in light of the high Gibbs free energy for charge recombination (ΔGCR=?1.39 eV), suggests a back‐electron transfer process occurring in the so‐called Marcus inverted region. Notably, in system 3 lacking the interchromophoric spacer, photoinduced charge separation followed by charge recombination occur within 20 ps. This is a consequence of the close vicinity of the donor–acceptor partners and of a virtually activationless electron transfer process. These results indicate that the strongly electron‐accepting cyanobuta‐1,3‐dienes might become promising alternatives to quinone‐, perylenediimide‐, and fullerene‐derived acceptors in multicomponent modules featuring photoinduced electron transfer. 相似文献
83.
Vitagliano L Vergara A Bonomi G Merlino A Verde C di Prisco G Howes BD Smulevich G Mazzarella L 《Journal of the American Chemical Society》2008,130(32):10527-10535
84.
Chris Binns Pilar Prieto Stephen Baker Paul Howes Ruggero Dondi Glenn Burley Leonardo Lari Roland Kr?ger Andrew Pratt Sitki Aktas John K. Mellon 《Journal of nanoparticle research》2012,14(9):1-16
In this study, efforts were placed in giving some in vitro key clues to the question on which is more efficient for the cancer hyperthermia between intracellular and extracellular modalities. Near infrared (NIR) photothermal responsive gold nanorods (GNRs) were adopted to cause cellular thermolysis either from inside or outside of cells. GNRs were synthesized with the size of 30.4?nm (in length)?×?8.4?nm (in width). Demonstrated by ICP-MS (inductively coupled plasmon mass spectroscopy), UV?CVis spectroscopy and transmission electron microscopy analyses, various cell uptake doses of nanoparticles were differentiated due to different molecular designs on GNRs surfaces and different types of cells chosen (three cancer cell lines and three normal ones). Under our continuous wavelengths (CW) NIR irradiation, it resulted that the cells which internalized GNRs died faster than the cells surrounded by GNRs. Furthermore, fluorescent images and flow cytometry data also showed that the NIR photothermal therapeutic effect was greater when the amount of internalized GNRs per cell was larger. Generally speaking, the GNRs assisted intracellular hyperthermia exhibited more precise and efficient control on the selective cancer ablation. To a larger degree, such a relationship between GNRs distribution and hyperthermia efficiency might be applied to wider spectra of cell types and heat-producing nanoparticles, which provided a promise for future cancer thermal therapeutic designs. 相似文献