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101.
102.
Aurica Farcas Giulia Tregnago Ana‐Maria Resmerita Sarah Taleb Dehkordi Sophie Cantin Fabrice Goubard Pierre‐Henri Aubert Franco Cacialli 《Journal of polymer science. Part A, Polymer chemistry》2014,52(4):460-471
The photophysical properties of two polyrotaxanes ( PFBTh?PSβCD and PFBTh?PMeβCD ) composed of fluorene and bithiophene encapsulated into permodified β‐cyclodextrin cavities have been investigated and compared with those of the reference PFBTh . Rotaxane formation results in improvements of the thermal stability, solubility in common organic solvents, as well as better film forming ability combined with a high transparency. As expected PFBTh and its encapsulated forms absorb at wavelengths beyond 510 nm, and time‐resolved photoluminescence (PL) in solution shows a well‐define vibronic structures with a predominance of the 0‐0 transitions and an energy difference of 0.16 eV. The fluorescence lifetimes follow a monoexponential decay with a value τ = 630 ± 30 ps. Atomic force microscopy, AFM, indicated a tendency of polyrotaxanes to organize into fibers. The advancing contact angles indicated higher surface hydrophobicity and lower surface free‐energy values for polyrotaxanes compared with their unthreaded analogues. The device based on PFBTh?PSβCD: PCBM in a 1/1 w/w ratio under simulated AM 1.5G illumination at 100 mW cm?2 exhibited improved photovoltaic parameters of cells, resulted in high Voc (0.68 V), Jsc (1.65 mA cm?2), FF (31.6%), and PCE (0.35) values, compared with PFBTh or PFBTh?PMeβCD , respectively. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 460–471 相似文献
103.
104.
Franco Cataldo Giancarlo Angelini Donatella Capitani Marco Gobbino Ornella Ursini Fabrizio Forlini 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(10):839-849
This paper is dedicated to the memory of our friend and colleague Annalaura Segre. The chemical structure of a series of β (-)-pinene polymers (PBP) obtained by radiation-induced polymerization, free radical initiation, cationic polymerization over a Friedel-Craft catalyst and by coordinative polymerization over a Ziegler-Natta catalyst has been fully elucidated by 1H and 13C-NMR spectroscopy. 2D NMR techniques have been applied in order to assign all the NMR resonances to the structures of the PBP investigated. The NMR spectra show that the most regular PBP structure is obtained by radiation-induced polymerization followed by the free radical initiated polymerization. The most defective structure has been observed in the case of PBP prepared by cationic mechanism over a Friedel-Crafts catalyst. The discussion accounts for different types of defects and cross-links present in the PBPs investigated whose fundamental structure is based on the p-menthene repeating unit. NMR self-diffusion measurements have been performed to evaluate the molecular weight of all the PBP investigated. The highest molecular weight (2600 Dalton) was found in the case of PBP prepared by Ziegler-Natta catalyst, while the lowest molecular weight was found in the case of PBP prepared by radiation-induced polymerization (about 1000 Dalton). 相似文献
105.
Juan Saulo Gonzlez‐Gonzlez Itzia I. Padilla‐Martínez Efrn V. García‐Bez Olivia Franco‐Hernndez Francisco J. Martínez‐Martínez 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(1):66-69
In the title compound, C24H36N6O6·C2H6OS, the carbonyl groups are in an antiperiplanar conformation, with O=C—C=O torsion angles of 178.59 (15) and −172.08 (16)°. An intramolecular hydrogen‐bonding pattern is depicted by four N—H...O interactions, which form two adjacent S(5)S(5) motifs, and an N—H...N interaction, which forms an S(6) ring motif. Intermolecular N—H...O hydrogen bonding and C—H...O soft interactions allow the formation of a meso‐helix. The title compound is the first example of a helical 1,2‐phenylenedioxalamide. The oxalamide traps one molecule of dimethyl sulfoxide through N—H...O hydrogen bonding. C—H...O soft interactions give rise to the two‐dimensional structure. 相似文献
106.
A convenient synthesis of the cyclohexyl, (1R,3R,4S)-3-P-menthyl and (15-endo)-2-bomyl glyoxylates, from the respective alcohols and other very available materials, as a model applicable to that of other chiral, sensitive giyoxylates, is described. 相似文献
107.
Acetyl derivatives of alcoholic and phenolic hydroxyl groups represent not only useful educts, intermediates and products in organic, bioorganic and pharmaceutical chemistry, but also interesting derivatives for isolation, purification and characterization of alcohols and phenols (especially for natural products). Furthermore, the acetylation reaction is frequently used for the protection of hydroxyl function. In general, however, acetoxy-groups may be highly resistent to hydrolysis so that their conversion into hydroxyl groups often requires strongly basic or acidic media, expensive and/or hardly available reagents, complicated procedures. These conditions may be incompatible with sensitive substrates or with other insufficiently stable groups present in the molecular residue.1,2 Very similar arguments are sound for some hydrazide derivatives of carboxylic acids.1,3,4 相似文献
108.
Optically active (2RS,3S)-2-(ethanediyldioxyethyl)-3-methylpentanal (1) and (3RS,4S)-4-methyl-3-(N-methylthiazolidine-2-yl)-hexanal (2) were prepared from (3RS,4S)-4-methyl-3-(N-methyl-thiazolidine-2-yl)-1,1-ethanediyldioxyhexane. 相似文献
109.
The synthesis of the title compound is described. The key-step is the photochemical coupling between 5-iodo-2-thienylcarbaldehyde and 2-bromothio-phene to give 5-bromo-2,2′-bithienyl-5′-carbaldehyde. 相似文献
110.
The selective and efficient acetylation of the hemiacetal hydroxyl in the equilibrium mixture between RCl2C(OAll)OH and AllOH/RCl2CHO was achieved using the acylating system Ac2O/Et3N/dimethylaminopyridine (DMAP).