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[reaction: see text] Following the discovery that meso-substituted corroles are formed in solvent-free condensation of pyrrole with aldehydes, we demonstrate that a small variation in the methodology is suitable for facile synthesis of cobalt(III) corrole and hexaphyrin. These compounds, as well as three noncyclic products, were fully characterized by spectroscopy and X-ray crystallography. 相似文献
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The reaction of α-halosubstituted β-ethoxyvinyl trifluoromethyl ketones with 2-aminopyridine gives 3-trifluoroacetyl imidazo[1,2-a]pyridine and 3-halo-1,1,1-trifluoro-4-(2-pyridinylamino)-3-buten-2-ones. The product ratio depends on the nature of the α-halogen atom and the solvent. 相似文献
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Aidar T. Gubaidullin Vladimir F. Mironov Gulnara A. Ivkova Igor A. Litvinov Irina V. Konovalova Liliya M. Burnaeva 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1)
Abstract Hexafluoroacetone imine easily interacts with compounds (I, R = OMe, OCH2CF2CHF2, NEt2, Ph) in two directions unlike hexafluoroacttone and gives 1,4,2-oxazaphosphepines (II) (pathway I) or 1,3,2-oxszaphosphepines (III) (pathway 2). The compound (II) (R = NEt2) lightly hydrolyzes to yield the salt (IV). The structure of heterocycles II-IV) has been confirmed by X-ray analysis (see fig. I, II, R = OMe; fig. 2, IV). The detail structural peculiarities of the compounds am discussed. 相似文献
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Liliya Dubenska Olha Dushna Solomiya Pysarevska Mykola Blazheyevskiy 《Electroanalysis》2020,32(3):626-634
In present paper we described a new simple voltammetric method of determination of nefopam alkaloid and its metabolite – N‐oxide. N‐oxide of nefopam is reduced at the dropping mercury electrode (DME) and silver solid amalgam electrodes (AgSAE), which can effectively replace mercury and chemically modified electrodes. The reduction consists of two one‐electron stages each accompanied with one proton transfer. N‐oxide of nefopam can be obtained from nefopam substance by oxidation with potassium peroxymonosulfate. It was studied the effect of various factors on N‐oxide quantitative yield (pH, oxidation duration, reagents concentration) as well as on the reduction of N‐oxide at DME and p‐AgSAE (pH, the nature of background electrolyte, potential and time of accumulation). It was showed that the reduction current linearly increased with increasing of concentration of analgesic. Limit of quantiation is 10?6 mol L?1 at DME and 10?7 mol L?1 at p‐AgSAE. The developed method was applied for the analysis of commercial drug solution for injection “Nefopam” with recovery of 96.7 %, as well as for the spiked human urine samples. Excellent repeatability with a relative standard deviation below 5 % was achieved. 相似文献
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Dmitry A. Gruzdev Galina L. Levit Victor P. Krasnov Evgeny N. Chulakov Liliya Sh. Sadretdinova Aleksandr N. Grishakov Marina A. Ezhikova Mikhail I. Kodess Valery N. Charushin 《Tetrahedron: Asymmetry》2010,21(8):936-942
A comparative study of the kinetic resolution of racemic 2-methyl-1,2,3,4-tetrahydroquinoline and 2,3-dihydro-3-methyl-4H-1,4-benzoxazine using N-phthaloyl-(S)-amino acyl chlorides as chiral acylating agents is described. Temperature and solvent effects on the stereochemical features have been examined. It has been found that N-phthaloyl-(S)-phenylalanyl and N-phthaloyl-(S)-2-phenylglycyl chlorides bearing aromatic substituents close to the stereogenic centre are more stereoselective acylating agents than N-phthaloyl-(S)-alanyl chloride. For the preparative kinetic resolution of racemic amines N-phthaloyl-(S)-phenylalanyl chloride proved to be the most appropriate chiral acylating agent. 相似文献
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Wang M Tang Y Sato S Vugmeyster L McKnight CJ Raleigh DP 《Journal of the American Chemical Society》2003,125(20):6032-6033
There is considerable interest in small proteins that fold very rapidly. These proteins have become attractive targets for both theoretical and computational studies. The independently folded 36-residue villin headpiece subdomain has been the subject of a number of such studies and is predicted to fold quickly. We demonstrate using dynamic NMR line-shape analysis that the protein folds on the time scale of 10 mus. Folding rates were directly estimated between 56 and 78 degrees C using resolved protein resonances from three different residues at both 500 and 700 MHz. The rates estimated using different residues and different field strengths agree well with each other. The estimated folding rate lies between 0.5 and 2.0 x 105 s-1 over this temperature range. The folding rate depends only weakly on temperature. 相似文献