全文获取类型
收费全文 | 147篇 |
免费 | 1篇 |
专业分类
化学 | 105篇 |
晶体学 | 2篇 |
力学 | 1篇 |
数学 | 14篇 |
物理学 | 26篇 |
出版年
2023年 | 2篇 |
2022年 | 5篇 |
2021年 | 10篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2018年 | 3篇 |
2017年 | 3篇 |
2016年 | 4篇 |
2015年 | 2篇 |
2014年 | 2篇 |
2013年 | 13篇 |
2012年 | 6篇 |
2011年 | 7篇 |
2010年 | 2篇 |
2009年 | 5篇 |
2008年 | 6篇 |
2007年 | 7篇 |
2006年 | 3篇 |
2005年 | 6篇 |
2004年 | 4篇 |
2003年 | 3篇 |
2002年 | 4篇 |
2001年 | 1篇 |
2000年 | 3篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1995年 | 5篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1988年 | 4篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1983年 | 6篇 |
1982年 | 2篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1970年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1937年 | 1篇 |
排序方式: 共有148条查询结果,搜索用时 343 毫秒
51.
52.
53.
54.
Patrycja Sowa Dana Marcin
kov Micha Miek Ewelina Sidor Jaroslav Legth Magorzata Dugan 《Molecules (Basel, Switzerland)》2020,25(23)
Plants from Asteraceae family are widely used for their therapeutic effects in the treatment of gastrointestinal diseases, but the consequences of excessive intake still need to be studied. The aims of this study were the evaluation of cytotoxicity, measurement of antioxidant properties and determination of polyphenolic profile of Tanacetum vulgare L. (tansy), Achillea millefolium L. (yarrow) and Solidago gigantea Ait. (goldenrod) ethanolic extracts. The cytotoxicity of extracts was monitored by xCELLigence system in real time by using porcine intestinal epithelial cell line (IPEC-1) and by measurement of changes in metabolic activity ((3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) (MTS) assay). The antioxidant properties were measured by spectrophotometric methods and polyphenolic profiles were determined by HPLC-DAD for 50% ethanol extracts (10% w/v). Strong cytotoxic effect was recorded for tansy and yarrow extracts (125–1000 µg/mL) by xCELLigence system and MTS assay. Conversely, a supportive effect on cell proliferation was recorded for goldenrod extracts (125 µg/mL) by the same methods (p < 0.001). The antioxidant activity was in good correlation with total polyphenolic content, and the highest value was recorded for goldenrod leaves, followed by tansy leaves, goldenrod flowers and yarrow leaf extracts. The goldenrod extracts were abundant with flavonoids, whereas phenolic acid derivatives predominated in the polyphenolic profile of tansy and yarrow. 相似文献
55.
R. P. Kambour J. M. Caraher C. L. Fasoldt G. T. Seeger N. M. Sowa D. M. White 《Journal of Polymer Science.Polymer Physics》1995,33(3):425-431
The addition of a high-Tg aromatic diluent to bisphenol A polycarbonate (PC) reduced Tg and melt viscosity while raising elastic modulus and yield stress substantially. Ultimate tensile elongation and impact toughness were badly affected. However, the addition to these antiplasticized blends of a small amount of a rubber modifier restored impact toughness and elongation but left the blend with increased melt fluidity and ambient stiffness re: neat PC. The key to this rebalancing of the properties of PC was found to be the disappearance of the plane strain crack instability that is a hallmark of the neat resin. The deformation mechanism in all the rubber-containing blends in all failure tests, regardless of geometric constraint and strain rate was found to be shear flow alone. The large plastic zone seen at the plane strain crack tip appears to involve rubber particle cavitation as well. © 1995 John Wiley & Sons, Inc. 相似文献
56.
S. Sowa W. Watanabe J. Nishii K. Itoh 《Applied Physics A: Materials Science & Processing》2005,81(8):1587-1590
A single femtosecond laser pulse creates a filamentary structural change along the optical axis inside bulk poly(methyl methacrylate).
The filamentary structural change was revealed to be a cylindrical cavity based on scanning electron microscope examination,
the presence of capillary action, and analysis of diffraction by an embedded diffraction grating. The cavity had a diameter
of 0.8 μm and a length of 125 μm.
PACS 42.65.Jx; 42.70.Jk 相似文献
57.
58.
The far-infrared reflection spectrum of KCN and NaCN in their cubic disordered phases is measured between 20 and 400 cm?1 with dispersive Fourier-spectroscopy and the complex dielectric function ε̂(ω) is evaluated. At 295 K KCN exhibits a well defined TO mode at 148 cm?1. The LO mode is at 234 cm?1. The dielectric function of NaCN between 295 and 363 K is more complicated. Below 150 cm?1 it can be approximated by an overdamped oscillator at 120 cm?1. 相似文献
59.
Mohr GJ Müller H Bussemer B Stark A Carofiglio T Trupp S Heuermann R Henkel T Escudero D González L 《Analytical and bioanalytical chemistry》2008,392(7-8):1411-1418
Eight new acidochromic dyes have been synthesised that can be used for optically monitoring pH in the range from 3 to 12. Their corresponding pK(a) values have been both measured and calculated theoretically by means of density functional theory. The synthesis of these new dyes is facile without the need for chromatographic purification. The dyes can be covalently linked to polymers containing hydroxyl functions such as cellulose, polyurethane hydrogel, and hydroxyalkyl methacrylate. The resulting sensor layers exhibit significant colour changes both in the UV and in the visible spectral range. 相似文献
60.
Dr. Patricia Korn Arno Classen Dr. Sudarshan Murthy Dr. Riccardo Guareschi Mirko M. Maksimainen Barbara E. Lippok Albert Galera-Prat Sven T. Sowa Catharina Voigt Prof. Dr. Giulia Rossetti Prof. Dr. Lari Lehtiö Prof. Dr. Carsten Bolm Prof. Dr. Bernhard Lüscher 《ChemistryOpen》2021,10(10):939-948
Intracellular ADP-ribosyltransferases catalyze mono- and poly-ADP-ribosylation and affect a broad range of biological processes. The mono-ADP-ribosyltransferase PARP10 is involved in signaling and DNA repair. Previous studies identified OUL35 as a selective, cell permeable inhibitor of PARP10. We have further explored the chemical space of OUL35 by synthesizing and investigating structurally related analogs. Key synthetic steps were metal-catalyzed cross-couplings and functional group modifications. We identified 4-(4-cyanophenoxy)benzamide and 3-(4-carbamoylphenoxy)benzamide as PARP10 inhibitors with distinct selectivities. Both compounds were cell permeable and interfered with PARP10 toxicity. Moreover, both revealed some inhibition of PARP2 but not PARP1, unlike clinically used PARP inhibitors, which typically inhibit both enzymes. Using crystallography and molecular modeling the binding of the compounds to different ADP-ribosyltransferases was explored regarding selectivity. Together, these studies define additional compounds that interfere with PARP10 function and thus expand our repertoire of inhibitors to further optimize selectivity and potency. 相似文献