全文获取类型
收费全文 | 144篇 |
免费 | 2篇 |
国内免费 | 2篇 |
专业分类
化学 | 96篇 |
力学 | 2篇 |
数学 | 30篇 |
物理学 | 20篇 |
出版年
2021年 | 5篇 |
2020年 | 4篇 |
2019年 | 2篇 |
2017年 | 3篇 |
2016年 | 3篇 |
2015年 | 4篇 |
2014年 | 3篇 |
2013年 | 5篇 |
2012年 | 13篇 |
2011年 | 8篇 |
2010年 | 7篇 |
2009年 | 5篇 |
2008年 | 6篇 |
2007年 | 4篇 |
2006年 | 10篇 |
2005年 | 10篇 |
2004年 | 13篇 |
2003年 | 7篇 |
2002年 | 1篇 |
2001年 | 2篇 |
2000年 | 3篇 |
1999年 | 1篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1982年 | 1篇 |
1978年 | 1篇 |
1974年 | 1篇 |
1966年 | 1篇 |
1958年 | 1篇 |
排序方式: 共有148条查询结果,搜索用时 15 毫秒
11.
Carmen van der Linde Monica Barone Silvia Turroni Patrizia Brigidi Enver Keleszade Jonathan R. Swann Adele Costabile 《Molecules (Basel, Switzerland)》2021,26(8)
The response of a coeliac and a healthy gut microbiota to the green algae Chlorella pyrenoidosa was evaluated using an in vitro continuous, pH controlled, gut model system, which simulated the human colon. The effect of C. pyrenoidosa on the microbial structure was determined by 16S rRNA gene sequencing and inferred metagenomics, whereas the metabolic activitywas determined by1H-nuclear magnetic resonancespectroscopic analysis. The addition of C. pyrenoidosa significantly increased the abundance of the genera Prevotella, Ruminococcus and Faecalibacterium in the healthy donor, while an increase in Faecalibacterium, Bifidobacterium and Megasphaera and a decrease in Enterobacteriaceae were observed in the coeliac donor. C. pyrenoidosa also altered several microbial pathways including those involved in short-chain fatty acid (SCFA) production. At the metabolic level, a significant increase from baseline was seen in butyrate and propionate (p < 0.0001) in the healthy donor, especially in vessels 2 and 3. While acetate was significantly higher in the healthy donor at baseline in vessel 3 (p < 0.001) compared to the coeliac donor, this was markedly decreased after in vitro fermentation with C. pyrenoidosa. This is the first in vitro fermentation study of C. pyrenoidosa and human gut microbiota, however, further in vivo studies are needed to prove its efficacy. 相似文献
12.
The European Physical Journal H - The widespread positivist approach of physics research in Italy at the turn of the XIX and XX centuries did not provide a fertile ground for the scientific debate... 相似文献
13.
Roderick C. Jones Brian W. Skelton Vicki-Anne Tolhurst Allan H. White Adele J. Wilson Allan J. Canty 《Polyhedron》2007
A convenient synthetic method for the preparation of organothiomethylpyridine ligands 2-(RSCH2)C5H4N (R = Ph (L1), Me (L2)), 2-MeS–6-Me-C5H3N (L3), and 2-MeS–4-Me-C5H3N (L4) via the initial lithiation of substituted 2-picolines followed by the nucleophilic reaction with a diorganyldisulfide is described. The complexes [PtBr2L] (L = L1–L4) have been prepared in good to high yields as yellow solids with low solubility in organic solvents. The solid state structures of the complexes have been determined, showing the spatial arrangement of the complexes to depend significantly upon varying substituents within the ligand. The complexes undergo oxidation by bromine to form the tetravalent complexes [PtBr4(L)] (L = L1–L4). The solid state structures of [PtBr4(L2)] and [PtBr4(L4)] have been determined, and shown to be monomeric with the ligand chelating the platinum centre. 相似文献
14.
15.
Bolognese A Correale G Manfra M Lavecchia A Novellino E Barone V 《Organic & biomolecular chemistry》2004,2(19):2809-2813
Microwave irradiation of a mixture of benzylidene-anilines and mercaptoacetic acid in benzene gives 1,3-thiazolidin-4-ones in very high yield (65-90%), whereas the same reaction performed through using the conventional method, at reflux temperature, requires a much longer time and gives a much lower yield (25-69%). This difference seems to be due to some intermediates and by-products formed during the conventional reaction. On the basis of 1H NMR studies, two different mechanisms, acting in benzene and in DMF, respectively, have been hypothesized for the thiazolidin-4-one system formation. 相似文献
16.
17.
Pata Vittorino; Zheng Ken Xiaojun; Zucchi Adele 《Journal London Mathematical Society》2000,61(2):604-616
Every subalgebra of L(H) which is isometrically weak*-homeomorphicwith H() is reflexive, when is a finitely connected regionin the complex plane. 相似文献
18.
In this paper we find a relation between the lattice of hyperinvariant subspaces of an operatorT of classC
0 over a multiply connected region and that of its Jordan modelT. It is shown that, generally, the lattice corresponding toT can be identified with a retract of that corresponding toT. Thus the Jordan model has the smallest lattice of hyperinvariant subspaces in a given quasisimilarity class. 相似文献
19.
20.
RolandW.S. Weber Abderrahim Madhour Heidrun Anke Adele Mucci Paolo Davoli 《Helvetica chimica acta》2005,88(11):2960-2966
A new hydroxylated carotenoic acid was isolated from the red yeast Sporobolomyces coprosmae and unambiguously identified as 2‐hydroxytorularhodin ( 1 ), i.e., (all‐E)‐3′,4′‐didehydro‐2‐hydroxy‐β,ψ‐caroten‐16′‐oic acid, by application of extensive 1D and 2D NMR techniques (gCOSY, gHSQC, gHMBC, DQS, gTOCSY, and ROESY). Hydroxylation of carotenoids at C(2) is uncommon in nature, very rare in fungi, and unprecedented for torularhodin. 相似文献