全文获取类型
收费全文 | 89篇 |
免费 | 0篇 |
专业分类
化学 | 76篇 |
晶体学 | 1篇 |
数学 | 3篇 |
物理学 | 9篇 |
出版年
2022年 | 1篇 |
2017年 | 1篇 |
2016年 | 3篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 9篇 |
2012年 | 2篇 |
2011年 | 1篇 |
2010年 | 4篇 |
2008年 | 7篇 |
2007年 | 7篇 |
2006年 | 8篇 |
2005年 | 3篇 |
2004年 | 5篇 |
2003年 | 6篇 |
2002年 | 5篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1993年 | 1篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1973年 | 2篇 |
排序方式: 共有89条查询结果,搜索用时 15 毫秒
31.
32.
Bernardi L Bonini BF Capito E Dessole G Comes-Franchini M Fochi M Ricci A 《The Journal of organic chemistry》2004,69(23):8168-8171
A nitrogen-containing superbase such as TMG was found to be an effective catalyst for the reaction between N-diphenylphosphinoyl imines and nitroalkanes. Exploiting a protocol that avoids the use of any solvent also during workup procedure, we synthesized a series of beta-nitroamines in excellent yields and high diastereomeric ratios. These results, combined with the capability of the indium in conjunction with Zn as the stoichiometric reducing agent to perform in aqueous medium reduction of the nitro group under mild reaction conditions, led us to devise a three-step, one-pot synthesis of a range of 1,2-diamines, making use of environmentally friendly procedures in the various steps. 相似文献
33.
34.
Stefano Mariani Maria Laura Ermini Simona Scarano Francesca Bellissima Massimo Bonini Debora Berti Maria Minunni 《Mikrochimica acta》2013,180(11-12):1093-1099
The use of nanoparticles (NPs) can substantially improve the analytical performance of surface plasmon resonance imaging (SPRi) in general, and in DNA sensing in particular. In this work, we report on the modification of the gold surface of commercial biochips with gold nanospheres, silica-coated gold nanoshells, and silver nanoprisms, respectively. The NPs were tethered onto the surface of the chip and functionalized with a DNA probe. The effects of tethering conditions and varying nanostructures on the SPRi signals were evaluated via hybridization assays. The results showed that coupling between planar surface plasmons and electric fields, generated by localized surface plasmons of the NPs, is mandatory for signal enhancement. Silver nanoprisms gave the best results in improving the signal change at a target DNA concentration of <50 nM by +50 % (compared to a conventional SPRi chip). The limit of detection for the target DNA was 0.5 nM which is 5 times less than in conventional SPRi. Figure
? 相似文献
35.
36.
Cataldo Valentini Duncan Gowland C. Grazia Bezzu Deborah Romito Nicola Demitri Nicola Bonini Davide Bonifazi 《Chemical science》2022,13(21):6335
In this paper we tackle the challenge of gaining control of the photophysical properties of PAHs through a site-specific N-doping within the structural aromatic framework. By developing a simple predictive tool that identifies C(sp2)-positions that if substituted with a heteroatom would tailor the changes in the absorption and emission spectral envelopes, we predict optimal substitutional patterns for the model peri-xanthenoxanthene (PXX) PAH. Specifically, TDDFT calculations of the electron density difference between the S1 excited state and S0 ground state of PXX allowed us to identify the subtleties in the role of sites i.e., electron donating or withdrawing character on excitation. The replacement of two C(sp2)-atoms with two N-atoms, in either electron donating or withdrawing positions, shifts the electronic transitions either to low or high energy, respectively. This consequently shifts the PXX absorption spectral envelop bathochromically or hypsochromically, as demonstrated by steady-state absorption spectroscopic measurements. Within the series of synthesised N-doped PXX, we tune the optical band gap within an interval of ∼0.4 eV, in full agreement with the theoretical predictions. Relatedly, measurements show the more blueshifted the absorption/emission energies, the greater the fluorescence quantum yield value (from ∼45% to ∼75%). On the other hand, electrochemical investigations suggested that the N-pattern has a limited influence on the redox properties. Lastly, depending on the N-pattern, different supramolecular organisations could be obtained at the solid-state, with the 1,7-pattern PXX molecule forming multi-layered, graphene-like, supramolecular sheets through a combination of weak H-bonding and π–π stacking interactions. Supramolecular striped patterned sheets could also be formed with the 3,9- and 4,10-congeners when co-crystallized with a halogen-bond donor molecule.In this paper we tackle the challenge of gaining control of the photophysical properties of PAHs through a site-specific N-doping within the structural aromatic framework. 相似文献
37.
38.
Deoxygenation of Pyridine N-oxides with sulphur monoxide generated from -2,3-diphenylthiiran-1-oxide
Bianca F. Bonini Gaetano Maccagnani Germana Mazzanti Paola Pedrini 《Tetrahedron letters》1979,20(20):1799-1800
Pyridine N-oxides are deoxygenated by sulphur monoxide. Electron withdrawing substituents lower drastically the yields of reduction. 相似文献
39.
Oxiranyl ring opening of trans-stilbene oxide gave rise to anti- or syn-2-bromo-1,2-diphenylethanols, using either MgBr(2).Et(2)O or MgBr(2).Et(2)O, NaBr, and KBr with Amberlyst 15, respectively. Starting from optically pure (R,R)-trans-stilbene oxide, (1R,2R)- and (1R,2S)-2-amino-1,2-diphenylethanols were obtained in high yield and ee. 相似文献
40.
Carlo Bonini Lucia ChiummientoMaria Teresa Lopardo Maddalena PullezFrançoise Colobert Guy Solladié 《Tetrahedron letters》2003,44(13):2695-2697
Differently protected glycidol derivatives (with Bn, TBDPS, TBS and MPM groups) have been tested for regioselective ring opening with vinylmagnesium bromide in order to obtain useful five-carbon functionalised homoallylic alcohols. Careful choice of the reagents and experimental conditions allowed a general access to important chiral synthons for asymmetric synthesis. 相似文献