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151.
Gagner J Johnson H Watkins E Li Q Terrones M Majewski J 《Langmuir : the ACS journal of surfaces and colloids》2006,22(26):10909-10911
Single bilayer membranes of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) were formed on micron thin-films of hydrophilized carbon nanotubes (CNT) by fusion of small unilamellar vesicles. The structure of the membrane was investigated using neutron reflectivity (NR). The underlying thin film of CNT was formed by chemical vapor deposition (CVD) in the presence of Fe catalyst, followed by reaction with 5 M nitric acid to render the film hydrophilic. We demonstrate that this platform lends support to homogeneous and continuous bilayer membranes that have promising applications in the fields of biomaterials, biosensors, and biophysics. 相似文献
152.
Elbieta Jesionka Anna Ciborska Wieslaw Wojnowski Jaroslaw Chojnacki 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(7):m321-m323
The title compounds, μ‐(tri‐tert‐butoxysilanethiolato‐κ2S:S)‐bis[(tetrahydrofuran‐κO)lithium(I)], [Li2(C12H27O3SSi)2(C4H8O)2], (I), and catena‐poly[[bis(μ‐tri‐tert‐butoxysilanethiolato)‐1:2κ2S;1κS:2κS,O‐dilithium(I)]‐μ‐dimethoxyethane‐κ2O:O′], [Li2(C12H27O3SSi)2(C4H10O2)]n, (II), were obtained by the reaction of tri‐tert‐butoxysilanethiol with metallic lithium. The crude product, when recrystallized from tetrahydrofuran (THF) yields (I), and when recrystallized from 1,2‐dimethoxyethane (DME) gives (II). Compound (I) forms centrosymmetric dimers in the solid state with an Li2S2 central core, whereas (II) forms infinitely long chains, in which the centrosymmetric dimeric units are linked together by the bidentate DME ligand (also residing on an inversion centre), thus forming a coordination polymer. The formation of a one‐dimensional structure in (II) is a consequence of replacement of a monodentate THF solvent molecule with a bidentate DME molecule. 相似文献
153.
Reaction rates of interfacial polycondensation of bisphenol A and chlorobisphenol II with isophthaloyl chloride were investigated. Rate constants and activation energies were determined The reaction rate was found to depend on stirring speed, catalyst, type of bisphenol, and temperature. 相似文献
154.
Luis Aparici Plaza Jaroslaw Chojnacki 《Acta Crystallographica. Section C, Structural Chemistry》2012,68(1):m24-m28
Chloroform was found to occupy the lattice of the protonated porphyrin and to promote crystallization of a different polymorphic form of a metalloporphyrin. The structure of 5,10,15,20‐tetraphenylporphyrin‐21,23‐diium dichloride chloroform octasolvate, C44H32N42+·2Cl−·8CHCl3, (I), in the solid state is described and compared with related solvates. The porphyrin macrocycle displays a distorted saddle shape, with chloride anions above and below the ring. Seven chloroform molecules are bound via C—H...Cl hydrogen bonds, while the link with the eighth solvent molecule is weaker. A new monoclinic polymorph of (5,10,15,20‐tetraphenylporphyrinato)copper(II), [Cu(C44H28N4)], (II), crystallized from chloroform, is also presented. 相似文献
155.
Lech Sznitko Pawel Karpinski Stanislaw Bartkiewicz Andrzej Miniewicz Jaroslaw Mysliwiec 《Central European Journal of Physics》2013,11(8):1024-1029
We study the formation of a surface relief grating and photoluminescence in a thin layers of a photochromic polymer doped with the luminescent dyes 3-(1,1-dicyanoethenyl)-1-phenyl-4,5-dihydro-1H-pyrazole and Rhodamine 6G. Surface topography measurements via Atomic Force Microscopy confirmed the existence of a surface relief grating with amplitudes as high as 650 nm both for doped and undoped photochromic polymers. Spectroscopic measurements carried out for polymers containing luminescent dyes have shown efficient photoluminescence and amplified spontaneous emission which is characteristic for gain media. 相似文献
156.
Jaroslaw Spychala 《合成通讯》2013,43(14):2497-2506
One-stage preparation of 1-[ω-(1,4,5,6-tetrahydropyrimidin-2-yl)alkyl]-thymines from 1-(ω-cyanoalkyl)thymines and a 1:1-mixture of 1,3-diaminopropane and ethanol saturated with hydrogen sulfide is described. 1-(2-Cyanoethyl)-thymine gave a facile reversal of the Michael reaction to thymine under the conditions used. The reaction of 1,3-bis(3-cyanobenzyl)thymine with the above reagent produced 1,3-bis[3-(1,4,5,6-tetrahydropyrimidin-2-yl)benzyl]thymine. 相似文献
157.
Jaroslaw Spychala 《合成通讯》2013,43(6):1083-1094
The Pinner synthesis was applied to the preparation of 4-(cyclic amidino)phenols in high yields from readily available 4-hydroxybenzimidic acid methyl ester hydrochloride and diaminoalkanes. An alternative attempt was made to convert 4-(hydroxy)thiobenzamide to 4-(1,4,5,6-tetrahydro-5-hydroxy-2-pyrimidiyl)phenol. A procedure for the preparation of 3,6-bis(4-hydroxyphenyl)- 1,2,4,5-tetrazine is reported here. The syntheses of 2,4-bis[4-(4,5-dihydro-lH-imidazol-2-yl)phenoxy]pyrimidine and 2-chloro-4-[4-(4,5-dihydro-lH-imidazol-2-yl)- phenoxylpyrimidine exemplify the use of the title synthetic intermediates. 相似文献
158.
Jaroslaw Saczewski Maria GdaniecPatrick J. Bednarski Anna Makowska 《Tetrahedron》2011,67(20):3612-3618
Hydroxylamine-O-sulfonic acid (HOSA) was used as an efficient nucleophilic amination reagent for 2-chloropyrimidines, 2-chloroquinolines, and 1-chloroisoquinoline. The newly obtained heteroaromatic hydroxylamine-O-sulfonates subjected to the reaction with acyl isothiocyanates underwent tandem nucleophilic addition-electrophilic 5-endo-trig cyclization. The mechanism of the cyclization was investigated with use of the long-range corrected hybrid density functional ωB97X-D/6-31+G∗ and SM8 (DMF) solvation model. The structures of the heteroaromatic hydroxylamine-O-sulfonates and N-(5-methoxy-2H-[1,2,4]thiadiazolo[2,3-a]pyrimidin-2-ylidene)benzamide were confirmed by single crystal X-ray analysis. N-(2H-[1,2,4]thiadiazolo[3,2-a]isoquinolin-2-ylidene)benzamide exhibited a pronounced in vitro cytostatic activity against human tumor cell lines SISO, LCLC, A-427, DAN-G, and RT-4 (IC50 in the range 1.47-2.97 μM). 相似文献
159.
Szajwaj B Moldoch J Masullo M Piacente S Oleszek W Stochmal A 《Natural product communications》2011,6(9):1293-1296
Two new derivatives of phenylpropenoic acids, N-trans-feruloyl-L-DOPA and O-trans-caffeoyl-malic acid dimethyl ester, along with four known N-trans-caffeoyl-L-DOPA (clovamide), N-trans-caffeoyl-L-DOPA-methyl ester, O-trans-caffeoyl-malic acid, O-trans-feruloyl-malic acid and quercetin 3-O-beta-D-glucopyranoside were isolated from the aerial parts of Trifolium pallidum. Their structures were elucidated by extensive spectroscopic methods including 1D- (1H, 13C) and 2D-NMR (DQF-COSY, HSQC, HMBC) experiments as well as mass spectrometry analysis. 相似文献
160.
Nachtigallová D Aquino AJ Szymczak JJ Barbatti M Hobza P Lischka H 《The journal of physical chemistry. A》2011,115(21):5247-5255
Nonadiabatic dynamics simulations performed at the state-averaged CASSCF method are reported for uracil. Supporting calculations on stationary points and minima on the crossing seams have been performed at the MR-CISD and CASPT2 levels. The dominant mechanism is characterized by relaxation into the S(2) minimum of ππ* character followed by the relaxation to the S(1) minimum of nπ* character. This mechanism contributes to the slower relaxation with a decay constant larger than 1.5 ps, in good agreement with the long time constants experimentally observed. A minor fraction of trajectories decay to the ground state with a time constant of about 0.7 ps, which should be compared to the experimentally observed short constant. The major part of trajectories decaying with this time constant follows the ππ* channel and hops to the ground state via an ethylenic conical intersection. A contribution of the relaxation proceeding via a ring-opening conical intersection was also observed. The existence of these two latter channels together with a reduced long time constant is responsible for a significantly shorter lifetime of uracil compared to that of thymine. 相似文献