全文获取类型
收费全文 | 105篇 |
免费 | 3篇 |
专业分类
化学 | 74篇 |
数学 | 11篇 |
物理学 | 23篇 |
出版年
2022年 | 1篇 |
2021年 | 1篇 |
2020年 | 2篇 |
2019年 | 1篇 |
2018年 | 3篇 |
2017年 | 3篇 |
2016年 | 3篇 |
2015年 | 3篇 |
2014年 | 3篇 |
2013年 | 8篇 |
2012年 | 4篇 |
2011年 | 8篇 |
2010年 | 5篇 |
2009年 | 9篇 |
2008年 | 15篇 |
2007年 | 7篇 |
2006年 | 3篇 |
2005年 | 2篇 |
2004年 | 2篇 |
2003年 | 7篇 |
2002年 | 5篇 |
2001年 | 3篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1988年 | 1篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1966年 | 2篇 |
排序方式: 共有108条查询结果,搜索用时 31 毫秒
1.
Tanja V. Soldatović Enisa Selimović Nevena Milivojević Milena Jovanović Biljana Šmit 《应用有机金属化学》2020,34(10):e5864
The novel heteronuclear complexes [{cis-PtCl (NH3)(μ-pyrazine)ZnCl (terpy)}](ClO4)2 (Pt-L1-Zn) and [{cis-PtCl (NH3)(μ-4,4′-bipyridyl)ZnCl (terpy)}](ClO4)2 (Pt-L2-Zn) (where terpy = 2,2′:6′,2′′-terpyridine, L1 = pyrazine, L2 = 4,4′-bipyridyl) were synthesized and characterized. The pKa values were determined, and based on them it was established that the π-acceptor ability of the pyrazine bridging ligand is more affective on lower pKa values. The kinetic measurements of the substitution reactions with biologically relevant ligands, such as guanosine-5′-monophosphate (5′-GMP), inosine-5′-monophosphate (5′-IMP) and glutathione (GSH), were studied at pH 7.4. The reactions were followed under pseudo-first-order conditions by UV–Vis spectrophotometry. The order of reactivity of the investigated biomolecules for the first reaction is 5′-GMP > 5′-IMP > GSH, while for the second is 5′-IMP > GSH. Pt-L1-Zn complex is more reactive than Pt-L2-Zn. The cytotoxic activity of heteronuclear Pt-L1-Zn and Pt-L2-Zn complexes was determined on human colorectal cancer cell line (HCT-116) and human breast cancer cell line (MDA-MB-231). Both complexes significantly reduced cell viability on tested cell lines and exerted significant cytotoxic effects, with better effect on HCT-116 cells than cisplatin, especially after 72 hr (IC50 < 0.52 μM). The Pt-L2-Zn complex showed higher activity against human breast cancer cells (MDA-MB-231) than cisplatin after 72 hr. The higher reactivity toward DNA constituent and significant cytotoxic activity may be attributed to the different geometry, Lewis acidity of different metal centers, as well as, to choice of bridging ligands. 相似文献
2.
The 2-dimensional BF theory is both a gauge theory and a topological Poisson σ-model corresponding to a linear Poisson bracket. In [3], Torossian discovered a connection which governs correlation functions of the BF theory with sources for the B-field. This connection is flat, and it is a close relative of the KZ connection in the WZW model. In this Letter, we show that flatness of the Torossian connection follows from (properly regularized) quantum equations of motion of the BF theory. 相似文献
3.
J. Glister G. Ron B.W. Lee R. Gilman A.J. Sarty S. Strauch D.W. Higinbotham E. Piasetzky K. Allada W. Armstrong J. Arrington H. Arenhövel A. Beck F. Benmokhtar B.L. Berman W. Boeglin E. Brash A. Camsonne J. Calarco J.P. Chen S. Choi E. Chudakov L. Coman B. Craver F. Cusanno J. Dumas C. Dutta R. Feuerbach A. Freyberger S. Frullani F. Garibaldi J.-O. Hansen T. Holmstrom C.E. Hyde H. Ibrahim Y. Ilieva C.W. de Jager X. Jiang M.K. Jones Hyekoo Kang A. Kelleher E. Khrosinkova E. Kuchina G. Kumbartzki J.J. LeRose R. Lindgren P. Markowitz S. May-Tal Beck E. McCullough D. Meekins 《Physics letters. [Part B]》2011
4.
5.
6.
Dilyana Paneva Laetitia Mespouille Nevena Manolova Philippe Degée Iliya Rashkov Philippe Dubois 《Macromolecular rapid communications》2006,27(17):1489-1494
Summary: Well‐defined poly[(ethylene oxide)‐block‐(sodium 2‐acrylamido‐2‐methyl‐1‐propane sulfonate)] diblock copolymers [P(EOm‐b‐AMPSn)], have been obtained by water‐based ATRP using α‐methoxy‐ω‐(2‐methylbromoisobutyrate) poly(ethylene oxide)s (MeO‐P[EO]m‐BriB with m ranging from 12 to 113) and CuBr · 2Bpy (Bpy for 2,2′‐bipyridyl) as macroinitiator and catalytic complex, respectively. Compared to direct polymerization in water, it has been demonstrated that the water/methanol (3:1, v/v) mixture is better suited for predicting the final number‐average molar mass from the initial monomer‐to‐macroinitiator molar ratio and achieving a quite narrow polydispersity, even at high monomer conversion ( ≈ 1.4 at 80% conversion). The effect of temperature, solvent mixture composition and addition of NaCl salt on the polymerization rate and extent of control over the copolymer molecular parameters have been highlighted as well.
7.
Corrections to the paper published in Vol. 121, No. 1, October, 1999 相似文献
8.
Rosica MladenovaMilena Ignatova Nevena Manolova Tsvetanka PetrovaIliya Rashkov 《European Polymer Journal》2002,38(5):989-999
Polyethers with 8-hydroxyquinolin-2-yl end groups (HOQCHN-POE-NCHQOH) were prepared by reaction between polyethers having amino end groups (Jeffamines ED®) and 8-hydroxyquinoline-2-carboxaldehyde. The HOQCHN-POE-NCHQOH polymers were characterized by size-exclusion chromatography, UV, IR, 1H and 13C NMR spectroscopy, and MALDI-TOF mass spectrometry. The complexation between HOQCHN-POE-NCHQOH and Fe3+ was studied by UV, IR spectroscopy and differential scanning calorimetry. The UV-irradiation of the complexes caused photodegradation of the polyether chains. It was shown that HOQCHN-POE-NCHQOH had high efficacy on remedying iron-deficient maize plants and exhibited very low-antibacterial activity towards non-pathogenic soil bacteria (B. subtilis). 相似文献
9.
Dilyana Paneva Laetitia Mespouille Nevena Manolova Philippe Dege Iliya Rashkov Philippe Dubois 《Journal of polymer science. Part A, Polymer chemistry》2006,44(19):5468-5479
Polyelectrolyte complexes (PECs) have been prepared from well‐defined (quaternized) poly[2‐(dimethylamino)ethyl methacrylate] (PDMAEMA) and high molecular weight poly(2‐acrylamido‐2‐methylpropane sodium sulfonate) (PAMPSNa) after a thorough study of their viscometric properties. The effect of pH and quaternization degree of PDMAEMA on PECs stoichiometry has been examined. PEC‐based materials have been characterized in terms of thermal stability, equilibrium swelling degree, and free/bound water composition. The stoichiometry and swellability of the physically crosslinked hydrogels obtained from fully quaternized PDMAEMA/PAMPSNa complexes do not depend on pH. In contrast, PECs made of non quaternized PDMAEMA and PAMPSNa are highly affected by pH, and could reversibly disintegrate at pH ≥ 9. Partially quaternized PDMAEMA/PAMPSNa PECs exhibit intermediate properties and form stable loose structures in the whole investigated pH range. Finally, stable dispersions of PECs nanoparticles have been successfully produced from dilute solutions of the complementary polyelectrolytes. The nanoparticle average diameter as determined by dynamic light scattering proved to depend on the molar fraction of DMAEMA‐based subunits and on the initial polyelectrolyte concentration. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5468–5479, 2006 相似文献
10.