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71.
A small library of squamocin analogues has been prepared and screened biologically (cytotoxicity, inhibition of mitochondrial complex I and complex III). To centre diversity on a crucial part of the molecule (i.e., the α,β-unsaturated lactone), an original and reliable lactone opening reaction has been discovered and exploited among other efficient reactions. 相似文献
72.
Rapid and efficient method for the quantification of lychnopholide in rat plasma by liquid chromatography–tandem mass spectrometry for pharmacokinetic application
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Larissa Lachi‐Silva João Paulo Barreto Sousa Maiara Camotti Montanha Sherwin K. B. Sy João Luis Callegari Lopes Denise Brentan Silva Norberto Peporine Lopes Andréa Diniz Elza Kimura 《Biomedical chromatography : BMC》2016,30(7):1092-1096
Lychnopholide is a sesquiterpene lactone usually obtained from Lychnophora and Eremanthus species and has pharmacological activities that include anti‐inflammatory and anti‐tumor. Lychnopholide isolated from Eremanthus matogrossenssis was analyzed in this study. The aims of this study were to develop and validate an analytical methodology by LC‐MS/MS and to quantify lychnopholide in rat plasma. Chromatographic separation was achieved on a C18 column using isocratic elution with the mobile phase consisting of methanol and water (containing 0.1% formic acid) at a flow rate of 0.4 mL/min. The detection was performed in multiple‐reaction monitoring mode using electrospray ionization in positive mode. The method validation was performed in accordance with regulatory guidelines and the results met the acceptance criteria. The linear range of detection was 10–200 ng/mL (r > 0.9961). The intra‐ and inter‐day assay variability were <6.2 and <11.7%, respectively. The extraction recovery was approximately 63% using liquid–liquid extraction with chloroform. Lychnopholide was detected in plasma up to 60 min after intravenous administration in rats. This rapid and sensitive method for the analysis of the sesquiterpene lactone lychnopholide in rat plasma can be applied to pharmacokinetic studies of this compound. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
73.
Introducing an In Situ Capping Strategy in Systems Biocatalysis To Access 6‐Aminohexanoic acid
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Dr. Johann H. Sattler Dr. Michael Fuchs Dr. Francesco G. Mutti Barbara Grischek Dr. Philip Engel Dr. Jan Pfeffer Prof. Dr. John M. Woodley Prof. Dr. Wolfgang Kroutil 《Angewandte Chemie (International ed. in English)》2014,53(51):14153-14157
The combination of two cofactor self‐sufficient biocatalytic cascade modules allowed the successful transformation of cyclohexanol into the nylon‐6 monomer 6‐aminohexanoic acid at the expense of only oxygen and ammonia. A hitherto unprecedented carboxylic acid capping strategy was introduced to minimize the formation of the dead‐end intermediate 6‐hydroxyhexanoic acid. For this purpose, the precursor ε‐caprolactone was converted in aqueous medium in the presence of methanol into the corresponding methyl ester instead of the acid. Hence, it was shown for the first time that esterases—specifically horse liver esterase—can perform the selective ring‐opening of ε‐caprolactone with a clear preference for methanol over water as the nucleophile. 相似文献
74.
Inourinvestigationonthebioactivecomponentsfromplants,thepreliminarybioassaystudiesshowedthatthepetroleumetherextractofEupaloriumadenOPhorumpossessedpotentialinsectantifeedantandinsectcideactivities.Inthepreviouspaper'.weisolatedanewphenylglucosidefromtheaerialpartsofE.adenophorum.FurtherstudyonflowersofE.adenophorumledtotheisolationoftwelvecompounds.Theirstructureswereidentifiedbyspectralanalysisandchemicalreactionasanewsesquiterpenelactonenamedeupatoranolide,2-acetoxy-3,4,6,11-tetradehydroc… 相似文献
75.
Mónica Moreno Monika Goikoetxea José C. de la Cal María J. Barandiaran 《Journal of polymer science. Part A, Polymer chemistry》2014,52(24):3543-3549
Novel waterborne polymeric materials based on renewable resource monomers have been prepared by the environmentally friendly miniemulsion polymerization of an oleic acid‐derivative monomer (MOA) and the α‐methylene‐γ‐butyrolactone (α‐MBL). The effect of the incorporation of different amounts of α‐MBL on kinetics and polymer microstructure is investigated. The estimation of the monomer reactivity ratios (rα‐MBL = 0.49 and rMOA = 1.26) shows the slight lower reactivity of the α‐MBL, resulting in a random copolymer moderately enriched with MOA at the beginning of the reaction. The thermal and mechanical properties of the polymers demonstrate that by incorporating the lactone it is possible to produce copolymers in a broad range of glass transition temperatures, with high thermal stability and improved mechanical properties. This study provides a new green route toward the bio‐sourced preparation of polymer latexes with tuneable properties, which can range from coatings to adhesives. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 3543–3549 相似文献
76.
77.
Ring strain energies (RSEs) have been calculated for oxygen‐containing spiro compounds using the group equivalent reaction (GER) formalism. The RSEs for all compounds studied were calculated from the energies of fully‐optimized structures at the MP2 + ZPE/cc‐pVDZ level and the more computationally costly G4(MP2) method. RSEs for selected compounds were also calculated with the CBS‐QB3 method, with less than 1 kcal/mol difference observed between G4(MP2) and CBS‐QB3. The difference between the less costly MP2 + ZPE and G4(MP2) methods was less than 1.5 kcal/mol. The highest RSEs were found for the compounds containing two three‐membered rings, and these compounds also exhibited the greatest excess strain energy (ESE) of about 12 kcal/mol. The RSEs of cyclic lactones vary with ring size differently than those of cyclic ethers. Cyclic ethers' RSEs decrease by a small amount from the three‐ to four‐membered rings then decrease drastically as the ring increases to 5 atoms, and approaches zero for the six‐membered ring, the same unexpected behavior as seen in cycloalkanes. Cyclic lactones' RSEs decrease linearly to almost zero from the three‐ to the five‐membered ring, then increase by 1–2 kcal/mol in the six‐membered ring. Lactone‐containing spiro compounds exhibit regularly diminishing ESE as the size of the lactone ring increases, down to about 3 kcal/mol in the δ‐lactone‐containing spiro compound. Substitution of methyl groups decreases RSE in these oxygen‐containing spiro compounds, while substitution of fluorine significantly increases RSE, as has been reported in other compounds. But RSE alone is shown to not correlate completely with chemical reactivity of these spiro compounds. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
78.
Cristian Paz Viviana Burgos Sebastin Suarez Ricardo Baggio 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(4):294-297
The title compound, dendocarbin A [systematic name: (1R,5aS,9aS,9bR)‐1‐hydroxy‐6,6,9a‐trimethyldodecahydronaphtho[1,2‐c]furan‐3‐one], C15H22O3, is a sesquiterpene lactone isolated from Drimys winteri var chilensis. The monoclinic phase described herein displays an identical molecular structure to the orthorhombic phase that we reported previously [Paz Robles et al. (2014). Acta Cryst. C 70 , 1007–1010], while varying significantly in chain pitch, and can thus be considered as a borderline case of one‐dimensional isostructural polymorphism. 相似文献
79.
The lactone 20R-25-norcycloartan-3β,6α,16β-triol-20,24-olide was synthesized from cyclosiversigenin.
Presented at the 1st International Symposium on Edible Plant Resources and the Bioactive Ingredients, Xinjiang, China, July
25–27, 2008.
Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 324–327, May–June, 2009. 相似文献
80.
Cheng Hai Gao Xu Hua Nong Shu Hua Qi Xiong Ming Luo Si Zhang Hai Rong Xiong 《中国化学快报》2010,21(11):1355-1357
A new nine-membered lactone, cladospolide E (1), was isolated from a culture broth of a marine fungus Cladosporium sp. F14. The structure of compound 1 was determined on the basis of extensive spectroscopic analysis, including 1D and 2D NMR data. 相似文献