全文获取类型
收费全文 | 69篇 |
免费 | 0篇 |
专业分类
化学 | 44篇 |
晶体学 | 1篇 |
力学 | 2篇 |
数学 | 4篇 |
物理学 | 18篇 |
出版年
2022年 | 3篇 |
2019年 | 3篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2016年 | 1篇 |
2013年 | 5篇 |
2011年 | 2篇 |
2010年 | 1篇 |
2009年 | 2篇 |
2006年 | 2篇 |
2004年 | 1篇 |
2003年 | 1篇 |
2002年 | 5篇 |
2001年 | 2篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有69条查询结果,搜索用时 31 毫秒
1.
[reaction: see text] Glycals are effective starting materials for the synthesis of enantiopure beta-ketone-delta-lactones. They are easily transformed, through a two-step, one-pot reaction, into the corresponding alpha,alpha'-dioxothiones which in turn can be quantitatively trapped with dienophiles in inverse electron-demand [4 + 2] cycloadditions. The reaction of dioxothione 8b with endo and exo glucals allowed the elaboration of a new protocol to prepare 2-thio- or 2-deoxydisaccharides stereoselectively. 相似文献
2.
3.
4.
Capozzi G Delogu G Fabbri D Marini M Menichetti S Nativi C 《The Journal of organic chemistry》2002,67(7):2019-2026
Sulfenylation of 6,6'-dimethoxy-2,2'-dihydroxybiphenyl, used as a racemic mixture and single enantiomers, by phthalimidesulfenyl chloride afforded the corresponding 3,3'-N,N'-dithiophthalimide with complete regioselectivity. Simple manipulations of the latter compound allowed access to the corresponding bis-thiol or o-thioquinone as useful intermediates for the synthesis of new sulfur-containing open-chain and macrocyclic C(2) enantiopure ligands. The application of this methodology to the preparation of a biphenyl bearing two cysteine units as potential HIV-1 protease inhibitor is also described. 相似文献
5.
M. Palumbo F. Baccichetti C. Antonello O. Gia A. Capozzi S. Marciani Magno 《Photochemistry and photobiology》1990,52(3):533-540
The furocoumarin derivative 3,4'-dimethyl-8-methoxypsoralen (DMe-8-MOP) exhibits remarkable antiproliferative activity, but is devoid of skin phototoxicity. To gain insight into this peculiar behaviour we investigated non-covalent and covalent binding of DMe-8-MOP to calf thymus DNA, along with DNA-synthesis inhibition and mutagenic activity. The non-covalent interaction of DMe-8-MOP with the nucleic acid is quite poor as shown by equilibrium dialysis, spectroscopic, chiroptical and hydrodynamic techniques. However, it exhibits relevant photobinding ability to DNA using both isolated nucleic acid samples and cellular systems. Unlike the large majority of congeners, DMe-8-MOP undergoes predominantly photochemical monoaddition to the double helical polynucleotide. Upon examination of the products obtained by enzymatic hydrolysis of DMe-8-MOP photomodified DNA, the formation of an unusual furan side adduct is proposed, which could account for the peculiar photochemical and photobiological properties of the 3,4'-dimethyl furocoumarin derivative. 相似文献
6.
The effect of certain chemicals known as singlet oxygen quenchers on the photoreaction between 8-MOP and DNA has been studied in vitro; sodium azide, l,4-diazabicyclo-(2,2,2)-octane, p-carotene and dimethylsolfoxide (used as a solvent) appeared to be capable of reducing significantly the 8-MOP ability to induce both monoadducts and cross-links in DNA. Therefore, these chemicals seem to be not useful in studying the singlet oxygen implication in the induction of biological effects of 8-MOP sensitization. 相似文献
7.
G. Capozzi V. Lucchini G. Modena 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-2)
Abstract Sulphenyl chlorides react in sulphur dioxide with acetylenes to give thiirenium chlorides 1 which lead to the final adducts 2. 相似文献
8.
G. Perna V. Capozzi M.C. Plantamura A. Minafra S. Orlando V. Marotta 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,29(4):541-545
ZnSe films were deposited by pulsed laser ablation on a crystalline GaAs substrate and on an amorphous quartz substrate. The
deposition process was performed with the same growth parameters. The films were investigated by means of X-ray diffraction,
reflectance and photoluminescence spectroscopy. The X-ray diffraction spectra have demonstrated that the films grow in a highly
oriented way but having different orientations, i.e. the films deposited on GaAs grow (100)-oriented and the films deposited on quartz grow (111)-oriented. Reflectance spectra
as a function of the temperature have been analysed by means of the classical oscillator model, in order to obtain the temperature
dependence of the band gap energy. This gives results comparable to those of ZnSe single crystals for ZnSe on GaAs, but it
is red-shifted for ZnSe on quartz, because of lattice and thermal strains. The photoluminescence measurements at T = 10 K confirm the better quality of ZnSe deposited on GaAs and show that pulsed laser ablation is a promising technique
to grow films having intrinsic luminescence even on an amorphous substrate.
Received 29 May 2002 Published online 31 October 2002
RID="a"
ID="a"e-mail: giuseppe.perna@ba.infn.it 相似文献
9.
10.
Arnaboldi C Benedek G Brofferio C Capelli S Capozzi F Cremonesi O Filipponi A Fiorini E Giuliani A Monfardini A Nucciotti A Pavan M Pedretti M Pessina G Pirro S Previtali E Sisti M 《Physical review letters》2006,96(4):042503
The mixed occurrence of s-wave and p-wave contributions in a first forbidden unique Gamow-Teller beta decay has been investigated for the first time by measuring the beta environmental fine structure (BEFS) in a 187Re crystalline compound. The experiment has been carried out with an array of eight AgReO4 thermal detectors operating at a temperature of approximately 100 mK. A fit of the observed BEFS spectrum indicates the p-wave electron emission as the dominant channel. The complete understanding of the BEFS distortion of the 187Re beta decay spectrum is crucial for future experiments aiming at the precise calorimetric measurement of the antineutrino mass. 相似文献