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71.
Azidopropylvinylsulfonamide as a New Bifunctional Click Reagent for Bioorthogonal Conjugations: Application for DNA–Protein Cross‐Linking 下载免费PDF全文
Jitka Dadová Dr. Milan Vrábel Matej Adámik Dr. Marie Brázdová Dr. Radek Pohl Prof. Dr. Miroslav Fojta Prof. Dr. Michal Hocek 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(45):16091-16102
N‐(3‐Azidopropyl)vinylsulfonamide was developed as a new bifunctional bioconjugation reagent suitable for the cross‐linking of biomolecules through copper(I)‐catalyzed azide–alkyne cycloaddition and thiol Michael addition reactions under biorthogonal conditions. The reagent is easily clicked to an acetylene‐containing DNA or protein and then reacts with cysteine‐containing peptides or proteins to form covalent cross‐links. Several examples of bioconjugations of ethynyl‐ or octadiynyl‐modified DNA with peptides, p53 protein, or alkyne‐modified human carbonic anhydrase with peptides are given. 相似文献
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Montes VA Pohl R Shinar J Anzenbacher P 《Chemistry (Weinheim an der Bergstrasse, Germany)》2006,12(17):4523-4535
The unique electron-transport and emissive properties of tris(8-quinolinolate) aluminum(III) (Alq(3)) have resulted in extensive use of this material for small molecular organic light-emitting diode (OLED) fabrication. So far, efforts to prepare stable and easy-to-process red/green/blue (RGB)-emitting Alq(3) derivatives have met with only a limited success. In this paper, we describe how the electronic nature of various substituents, projected via an arylethynyl or aryl spacer to the position of the highest HOMO density (C5), may be used for effective emission tuning to obtain blue-, green-, and red-emitting materials. The synthetic strategy consists of four different pathways for the attachment of electron-donating and electron-withdrawing aryl or arylethynyl substituents to the 5-position of the quinolinolate ring. Successful tuning of the emission color covering the whole visible spectrum (lambda=450-800 nm) was achieved. In addition, the photophysical properties of the luminophores were found to correlate with the Hammett constant of the respective substituents, providing a powerful strategy with which to predict the optical properties of new materials. We also demonstrate that the electronic nature of the substituent affects the emission properties of the resulting complex through effective modification of the HOMO levels of the quinolinolate ligand. 相似文献
74.
2‐Substituted dATP Derivatives as Building Blocks for Polymerase‐Catalyzed Synthesis of DNA Modified in the Minor Groove 下载免费PDF全文
Ján Matyašovský Dr. Pavla Perlíková Dr. Vincent Malnuit Dr. Radek Pohl Prof. Dr. Michal Hocek 《Angewandte Chemie (International ed. in English)》2016,55(51):15856-15859
2′‐Deoxyadenosine triphosphate (dATP) derivatives bearing diverse substituents (Cl, NH2, CH3, vinyl, ethynyl, and phenyl) at position 2 were prepared and tested as substrates for DNA polymerases. The 2‐phenyl‐dATP was not a substrate for DNA polymerases, but the dATPs bearing smaller substituents were good substrates in primer‐extension experiments, producing DNA substituted in the minor groove. The vinyl‐modified DNA was applied in thiol–ene addition and the ethynyl‐modified DNA was applied in a CuAAC click reaction to form DNA labelled with fluorescent dyes in the minor groove 相似文献
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Miloš Buděšínský Václav Vaněk Martin Dračínský Radek Pohl Lenka Poštová-Slavětínská Vladimír Sychrovský Jan Pícha Ivana Císařová 《Tetrahedron》2014
The six-membered saturated heterocycles—4-tert-butyl-1-methylpiperidine, 4-tert-butyl-1-methylphosphine, 4-tert-butyl-tetrahydro-2H-thiopyran, and 4-tert-butyl-tetrahydro-2H-selenopyran—were prepared as suitable model compounds with well-defined geometry for an NMR study of their oxidation products. The corresponding epimeric N-oxides, phosphinoxides, sulfoxides, and selenoxides were obtained by standard chemical preparation and also by in situ oxidation with meta-chloroperbenzoic acid directly in the NMR tube. The experimental 1H and 13C chemical shifts were compared with corresponding calculated data obtained by GIAO approach with DFT, MP2, and HF methods and various basis sets. The correlation of experimental versus calculated data showed the possibility to determine the stereochemistry of the epimeric oxidation products using fast DFT B3LYP/6-31G* method for both geometry optimization and NMR chemical shifts calculation. 相似文献
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Jan Vícha Michal Maloň Petra Veselá Otakar Humpa Miroslav Strnad Radek Marek 《Magnetic resonance in chemistry : MRC》2010,48(4):318-322
The 1H and 13C NMR resonances of 16 purine glucosides were assigned by a combination of one‐ and two‐dimensional NMR experiments, including gs‐COSY, gs‐HSQC, and gs‐HMBC, in order to characterize the effect of substituent and the position of glucose unit on the NMR chemical shifts. In addition, 15N NMR chemical shifts for selected derivatives were investigated by using 1H? 15N chemical shift correlation techniques. To map the influence of sugar moiety on the directly bonded nitrogen atom, selected N9‐glucosides and their ribose analogs were compared. Characteristic long‐range 1H? 15N coupling constants, measured by using 1H? 15N gradient‐selected single‐quantum multiple bond correlation (GSQMBC), are also reported and discussed. All compounds investigated here belong to cytokinins, an important group of plant hormones. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
79.
Alois Pískala Jií Gut Pavel Fiedler Milena Masojídkov David aman Radek Liboska 《Journal of heterocyclic chemistry》1993,30(5):1317-1324
Treatment of 3,5-dimethoxy-1,2,4-triazine ( 1a ) with methyl iodide was found to give depending on the reaction time triazinium iodide 2a , triaziniumolates 4a and 6a as well as methoxytriazinones 7a and 8a . Thermolysis of 2a gave triaziniumolates 4a and 6a . Reaction of 2a , 4a or methoxytriazinone 9a with methyl iodide in acetonitrile yielded as the sole product 6a . Reaction of 3-methoxy-5-methylthio-1,2,4-tri-azine (1b ) with methyl iodide gave triazinium iodide 2b and methylthio triazinone 7b . Hydrolysis of 2a,b afforded 4a . Reaction of 5-methoxy-3-methylthio-1,2,4-triazine ( 1c ) with methyl iodide gave triazinium iodide 2c , triaziniumolate 4b , triazinium iodide 5b and triazinone 8b . Hydrolysis of 2c yielded 4b and its thermolysis gave a mixture of 4b and 5b . Reaction of 2c , 4b and triazinone 9b with methyl iodide afforded 5b . Treatment of 3,5-bis(methylthio)-1,2,4-triazine ( 1d ) with methyl iodide was found to give a mixture of N1 and N2 methiodides 2d and 3d which gave on hydrolysis 4b and 8b , respectively. Methylation of 6-methyl derivatives 1c-g gave analogous results, however the proportions of N1 methylated products were lower and the reaction rates higher in comparison to their respective lower homologues 1a,c,d . The structures of the mesoionic dimethyl derivatives were assigned from uv, ir, 1H nmr and electron impact mass spectra. The structural assignments were eventually confirmed by quantum chemical calculations of net charge distributions, bond lengths and ipso angles of the C5?O bonds. 相似文献
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