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1.
Abstract The present work deals with the realization of composites with a polypropylene (PP) matrix and cellulosic fibers as reinforcement. In order to achieve a good adhesion with the PP matrix, the modification of different cellulosic fibers has been performed with various chemical functions: carboxylic anhydrides, isocyanates, vinylsulfone, and chlorotriazine systems. All these compatibilizing agents carry an alkyl chain or a PP chain. Grafting is evidenced by infrared and ESCA spectroscopies, and the grafting rates for the different chemicals are determined by microweighing measurements. Modification of the surface characteristics is followed by wettability tests and inverse gas chromatography. Determination of the water sorption isotherm for the treated fibers shows an important decrease in water regain in the case of isocyanate treatments in swelling medium. Enhancement of adhesion between fibers and the matrix is demonstrated by mechanical tests: the interfacial shear stress obtained by the microbond test increases by 70% for cellulosic fibers treated with maleated PP. This may be the result of entanglements between PP chains, but for macrocomposites the effect is much more limited due to the predominance of external factors during development of the composite. 相似文献
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In this paper, we extend and complete the classification of the generic singularities of the 3D-contact sub-Riemmanian conjugate locus in a neighborhood of the origin. 相似文献
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Dominic Thibeault Jean Legault Charles Gauthier Serge Lavoie Jimmy Bouchard 《合成通讯》2013,43(2):213-221
22(17 → 28)abeo-Lupene derivatives 5a and 6a were obtained after the acid-catalyzed E-ring expansion of 3-acetylbetulin (1a). Glycosylation of these dehydrated triterpenoids using Schmidt's trichloroacetimidate sugar donors in the presence of trimethylsilyl trifluoromethanesulfonate (TMSOTf) provided the new anhydrobetulin saponins 7b–7e in which the terminal olefin C-20(29) isomerizes to form a C-19 tetrasubstituted alkene. The preliminary cytotoxic evaluation revealed that saponins 7b–7d exhibited a moderate cytotoxic activity against A549, DLD-1, and WS1 human cell lines with IC50 ranging from 22 to 49 μM. 相似文献
5.
Joana Antunes Quentin Gauthier Vanessa Aguiar-Pulido George Duncan Bruce McCord 《Electrophoresis》2021,42(9-10):1168-1176
Tissue-specific differentially methylated regions (tDMRs) are regions of the genome with methylation patterns that modulate gene expression in those tissue types. The detection of tDMRs in forensic evidence can permit the identification of body fluids at trace levels. In this report, we have performed a bioinformatic analysis of an existing array dataset to determine if new tDMRs could be identified for use in body fluid identification from forensic evidence. Once these sites were identified, primers were designed and bisulfite modification was performed. The relative methylation level for each body fluid at a given locus was then determined using qPCR with high-resolution melt analysis (HRM). After screening 127 tDMR's in multiple body fluids, we were able to identify four new markers able to discriminate blood (2 markers), vaginal epithelia (1 marker) and buccal cells (1 marker). One marker for each target body fluid was also tested with pyrosequencing showing results consistent with those obtained by HRM. This work successfully demonstrates the ability of in silico analysis to develop a novel set of tDMRs capable of being differentiated by real time PCR/HRM. The method can rapidly determine the body fluids left at crime scenes, assisting the triers of fact in forensic casework. 相似文献
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Dr. Peter Wick Dr. Anna E. Louw‐Gaume Dr. Melanie Kucki Prof. Harald F. Krug Prof. Kostas Kostarelos Prof. Bengt Fadeel Prof. Kenneth A. Dawson Dr. Anna Salvati Prof. Ester Vázquez Dr. Laura Ballerini Dr. Mauro Tretiach Dr. Fabio Benfenati Dr. Emmanuel Flahaut Dr. Laury Gauthier Prof. Maurizio Prato Dr. Alberto Bianco 《Angewandte Chemie (International ed. in English)》2014,53(30):7714-7718
7.
M. Talebi-Esfandarani S. Rousselot M. Gauthier P. Sauriol G. Liang M. Dollé 《Journal of Solid State Electrochemistry》2016,20(7):1821-1829
LiFePO4/C material has been prepared using fast-melt synthesis method followed by grinding and carbon coating. The low-cost iron ore concentrate (IOC) and purified iron ore concentrate (IOP) were used as iron precursors in the melt process to reduce significantly the cost of LiFePO4/C. The same product was also synthesized using pure Fe2O3 under similar conditions as reference. The physical-chemical and electrochemical properties of samples were investigated. The X-ray Diffraction (XRD) results confirm the formation of an olivine structure of LiFePO4 with a minor amount of Li3PO4 and Li4P2O7 impurities for all the samples but no Fe2P. The power performances of LiFePO4/C using low-cost iron precursors were close to the sample using pure Fe2O3 precursor although capacity in mAh g?1 is somewhat lower. With the inherent presence of silicon and other metals species, multi-substitution may take place when using IOC as source of iron leading to a Li(Fe1-yMy)(P1-xSix)O4 general composition. Multi-substitution, however, allows a better cycling stability. Therefore, these iron precursors present a promising option in this field to reduce the cost of a large-scale synthesis of LiFePO4/C for Li-ion batteries application. 相似文献
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