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101.
This study outlines a simple method for pH-mediated stacking of natural and synthetic steroids facilitated with carboxymethyl-beta-CD. Sample stacking (10 kV, 60 s) is accomplished with 23 mM carboxymethyl-beta-CD in 50 mM 3-[cyclohexylamino]-1-propanesulfonic acid buffered at pH 10. Following stacking, steroidal compounds are separated in less than 5 min with a running buffer of 13 mM hydroxypropyl-beta-CD, 30 mM SDS in 200 mM phosphate buffered at pH 2.5. Using a 60 s electrokinetic injection, the limits of detection of estradiol, ethynyl estradiol, estrone, hydroxyprogesterone, progesterone, and 11-ketotestosterone range from 2 to 14 nM. For all steroids, the within-day and day-to-day reproducibility in migration time is < or =1 and < or =2% RSD, respectively. The within-day and day-to-day reproducibility in peak area is < or =9 and < or =22% RSD, respectively. The method is applied to fish plasma and holds potential to profile multiple steroids in a single biological sample. 相似文献
102.
Liudmila K. Kibardina Liliya I. Vagapova Alexander R. Burilov Airat R. Garyfzyanov Michael A. Pudovik 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-3):10-12
Abstract A method for the synthesis of novel phosphorylated aminoacetals was developed. The latter are involved in Mannich reaction as amine component with calix[4]resorcinol and formaldehyde to form tetrasubstituted macrocycles containing four acetal groups and four phosphonate (phosphine oxide) fragments on the “upper” rim of molecule with high yields. 相似文献
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Elvira S. Batyeva Lidiya I. Kursheva Liliya V. Frolova Anatolyi M. Il'in Rushaniya J. Valiullina Sergey V. Zakharov 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1)
Abstract Recently we have established that triphenyl- and trialkyltrithiophos-phites react with copper(1) halides with the formation of different typcs of occupies depending on substituents in the thioalkylgmup and on the conditions. Thesc complexes readily react with alcohols Rsulting in dialkylphosphorous acid [I]. We have assumed that the analogous phosphorylation of alcohols by (PhS), P and (AlkS)3P must be conducted in the presence of transition metal halides (CuCI, CuBr, CdCI2, CdI2, ZnC12, HgCl2, HgBr2) as well. 相似文献
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Nikolay Davydov Dr. Asiya Mustafina Dr. Vladimir Burilov Dr. Elena Zvereva Prof. Sergey Katsyuba Dr. Liliya Vagapova Prof. Alexander Konovalov Dr. Igor Antipin 《Chemphyschem》2012,13(14):3357-3364
The complex formation of d‐metal ions at the interface of TbIII‐doped silica nanoparticles modified by amino groups is introduced as a route to sensing d‐metal ions and some organic molecules. Diverse modes of surface modification (covalent and noncovalent) are used to fix amino groups onto the silica surface. The interfacial binding of d‐metal ions and complexes is the reason for the TbIII‐centered luminescence quenching. The regularities and mechanisms of quenching are estimated for the series of d‐metal ions and their complexes with chelating ligands. The obtained results reveal the interfacial binding of CuII ions as the basis of their quantitative determination in the concentration range 0.1–2.5 μM by means of steady‐state and time‐resolved fluorescence measurements. The variation of chelating ligands results in a significant effect on the quenching regularities due to diverse binding modes (inner or outer sphere) between amino groups at the interface of nanoparticles and FeIII ions. The applicability of the steady‐state and time‐resolved fluorescence measurements to sense both FeIII ions and catechols in aqueous solution by means of TbIII‐doped silica nanoparticles is also introduced. 相似文献
107.
The dynamics of porphyrin ring inversion of a number of Fe(III) complexes of octamethyltetraphenylporphyrin, (OMTPP)Fe(III); octaethyltetraphenylporphyrin, (OETPP)Fe(III); octaethyltetra(perfluorophenyl)porphyrin, (F(20)OETPP)Fe(III); and tetra-beta,beta'-tetramethylenetetraphenyl-porphyrin, (TC(6)TPP)Fe(III), having either one (Cl(-), ClO(4-)) or two [4-(dimethylamino)pyridine, 4-Me(2)NPy; 1-methylimidazole, 1-MeIm; tert-butylisocyanide, t-BuNC; or cyanide, CN(-)] axial ligands have been characterized by 1D dynamic NMR (DNMR) and 2D (1)H NOESY/EXSY spectroscopies as a function of temperature. The activation parameters, Delta H++, Delta S++, and Delta G++(298), and the extrapolated rate constants at 298 K for three chloride, one perchlorate, and three bis-(4-Me(2)NPy) complexes as well as [FeOETPP(1-MeIm)(2)]Cl, [FeOETPP(t-BuNC)(2)]ClO(4), and Na[FeOETPP(CN)(2)] have been determined. The results indicate that there is a wide range of flexibility for the porphyrin core (k(ex)(298) = 10-10(7) s(-1)) that decreases in the order TC(6)TPP > OMTPP > F(20)OETPP > or = OETPP, which correlates with increasing porphyrin nonplanarity. To determine the effect of axial ligands, we calculated the free energy of activation, Delta G++(298) for OETPPFe(III) bis-ligated with 4-Me(2)NPy, 1-MeIm, or 4-CNPy (approximately 59 kJ mol(-1)), and for complexes with small cylindrical ligands (t-BuNC and CN(-)) (approximately 37 kJ mol(-1)). These data suggest that the Delta G++(298) for planar ligand rotation is roughly 20-25 kJ mol(-1). 相似文献
108.
Olga V. Andreeva Bulat F. Garifullin Vladimir V. Zarubaev Alexander V. Slita Iana L. Yesaulkova Alexandrina S. Volobueva Mayya G. Belenok Maria A. Mankova Liliya F. Saifina Marina M. Shulaeva Alexandra D. Voloshina Anna P. Lyubina Vyacheslav E. Semenov Vladimir E. Kataev 《Molecules (Basel, Switzerland)》2021,26(12)
A series of 1,2,3-triazolyl nucleoside analogues in which 1,2,3-triazol-4-yl-β-d-ribofuranosyl fragments are attached via polymethylene linkers to both nitrogen atoms of the heterocycle moiety (uracil, 6-methyluracil, thymine, quinazoline-2,4-dione, alloxazine) or to the C-5 and N-3 atoms of the 6-methyluracil moiety was synthesized. All compounds synthesized were evaluated for antiviral activity against influenza virus A/PR/8/34/(H1N1) and coxsackievirus B3. Antiviral assays revealed three compounds, 2i, 5i, 11c, which showed moderate activity against influenza virus A H1N1 with IC50 values of 57.5 µM, 24.3 µM, and 29.2 µM, respectively. In the first two nucleoside analogues, 1,2,3-triazol-4-yl-β-d-ribofuranosyl fragments are attached via butylene linkers to N-1 and N-3 atoms of the heterocycle moiety (6-methyluracil and alloxazine, respectively). In nucleoside analogue 11c, two 1,2,3-triazol-4-yl-2′,3′,5′-tri-O-acetyl-β-d-ribofuranose fragments are attached via propylene linkers to the C-5 and N-3 atoms of the 6-methyluracil moiety. Almost all synthesized 1,2,3-triazolyl nucleoside analogues showed no antiviral activity against the coxsackie B3 virus. Two exceptions are 1,2,3-triazolyl nucleoside analogs 2f and 5f, in which 1,2,3-triazol-4-yl-2′,3′,5′-tri-O-acetyl-β-d-ribofuranose fragments are attached to the C-5 and N-3 atoms of the heterocycle moiety (6-methyluracil and alloxazine respectively). These compounds exhibited high antiviral potency against the coxsackie B3 virus with IC50 values of 12.4 and 11.3 µM, respectively, although both were inactive against influenza virus A H1N1. According to theoretical calculations, the antiviral activity of the 1,2,3-triazolyl nucleoside analogues 2i, 5i, and 11c against the H1N1 (A/PR/8/34) influenza virus can be explained by their influence on the functioning of the polymerase acidic protein (PA) of RNA-dependent RNA polymerase (RdRp). As to the antiviral activity of nucleoside analogs 2f and 5f against coxsackievirus B3, it can be explained by their interaction with the coat proteins VP1 and VP2. 相似文献
109.
110.