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991.
Marek Gołębiowski Aleksandra Ostachowska Monika Paszkiewicz Mieczysława I. Boguś Emilia Włóka Marta Ligęza-Żuber Piotr Stepnowski 《Chemical Papers》2016,70(10):1360-1369
Entomopathogenic fungi are referred to as potential candidates as insect pest control agents. The objective of the study was to identify fatty acids and amino acids from Conidiobolus coronatus cultured on two different media. Each medium was extracted with ethyl acetate and its mixtures with isopropanol, acetonitrile and methanol. Analyses of fatty acids and amino acids of entomopathogenic fungus C. coronatus were performed by means of gas chromatography coupled with mass spectrometry. The analysis showed that the fungus C. coronatus produces the following groups of compounds: fatty acids and amino acids; α- and β-glucopyranose were also identified. The identified fatty acids included 12–20, 22 and 24 carbon atoms per chain. The highest content of fatty acids was detected in a mycelium sample cultured in a liquid minimal medium extracted with ethyl acetate. The lowest content of these organic compounds was identified in mycelium cultured in a liquid nutrient-rich medium extracted with ethyl acetate–methanol mixture. Fatty acids were found to account for 62.0 mass % to 94.4 mass % of all organic compounds in the analyzed mycelia. C18:1 acids were detected in the highest amounts when ethyl acetate was used as the extracting agent. The identified amino acids accounted for 4 mass % to 21 mass % of all organic compounds. Upon extraction of C. coronatus mycelium samples with the ethyl acetate—methanol mixture, two anomeric forms of glucose were also identified. An analysis of the studied material confirmed, that the entomopathogenic fungus C. coronatus is a very rich source of organic compounds, which might encourage its further research so as to identify an even larger number of compounds being produced by this species. 相似文献
992.
Soluble Flavanthrone Derivatives: Synthesis,Characterization, and Application to Organic Light‐Emitting Diodes
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Kamil Kotwica Dr. Piotr Bujak Dr. Przemyslaw Data Wojciech Krzywiec Damian Wamil Dr. Piotr A. Gunka Lukasz Skorka Dr. Tomasz Jaroch Prof. Robert Nowakowski Prof. Adam Pron Prof. Andrew Monkman 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(23):7978-7986
Simple modification of benzo[h]benz[5,6]acridino[2,1,9,8‐klmna]acridine‐8,16‐dione, an old and almost‐forgotten vat dye, by reduction of its carbonyl groups and subsequent O‐alkylation, yields solution‐processable, electroactive, conjugated compounds of the periazaacene type, suitable for the use in organic electronics. Their electrochemically determined ionization potential and electron affinity of about 5.2 and ?3.2 eV, respectively, are essentially independent of the length of the alkoxyl substituent and in good agreement with DFT calculations. The crystal structure of 8,16‐dioctyloxybenzo[h]benz[5,6]acridino[2,1,9,8‐klmna]acridine ( FC‐8 ), the most promising compound, was solved. It crystallizes in space group P and forms π‐stacked columns held together in the 3D structure by dispersion forces, mainly between interdigitated alkyl chains. Molecules of FC‐8 have a strong tendency to self‐organize in monolayers deposited on a highly oriented pyrolytic graphite surface, as observed by STM. 8,16‐Dialkoxybenzo[h]benz[5,6]acridino[2,1,9,8‐klmna]acridines are highly luminescent, and all have photoluminescence quantum yields of about 80 %. They show efficient electroluminescence, and can be used as guest molecules with a 4,4′‐bis(N‐carbazolyl)‐1,1′‐biphenyl host in guest/host‐type organic light‐emitting diodes. The best fabricated diodes showed a luminance of about 1900 cd m?12, a luminance efficiency of about 3 cd A?1, and external quantum efficiencies exceeding 0.9 %. 相似文献
993.
Michał Stępień Piotr Handzlik Krzysztof Fitzner 《Journal of Solid State Electrochemistry》2016,20(10):2651-2661
The aim of the present work was to investigate electrochemical behavior of the Ti6Al7Nb alloy in the simulated body fluid (SBF) containing Ca2+, HCO3 ?, and HPO4 2? ions. At first, optimal conditions necessary for oxide nanotube formation were determined. The experiments were conducted in the 1 M (NH4)2SO4 with 0.5 wt% NH4F electrolyte at room temperature. Anodization of the alloy samples was carried out under variable external voltage U in the range from 10 to 40 V at room temperature. Obtained surface morphology was examined by SEM and X-ray techniques. Nanotube diameter was calculated and correlated with the imposed voltage. Having control over the size of nanotubes, samples with the obtained nanostructures of a chosen diameter were immersed into SBF solution with pH = 7.4 for a fixed period of time. Then, they were removed from the fluid and subjected to the electrochemical investigation. Corrosion current and corrosion potential were determined, and it was found that the best anticorrosion properties were obtained for heat-treated nanotube layer: i corr = 39 nA/cm2 and E corr = ?0.236 V vs Ag/AgCl. Finally, the interaction between the oxide surface and the solution was studied using polarization and electrochemical impedance spectroscopy (EIS) techniques. 相似文献
994.
Inside Cover: A Rotational BODIPY Nucleotide: An Environment‐Sensitive Fluorescence‐Lifetime Probe for DNA Interactions and Applications in Live‐Cell Microscopy (Angew. Chem. Int. Ed. 1/2016)
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995.
Tomasz Galica Julia Bkowicz Piotr Broda Ilona Turowska-Tyrk 《Acta Crystallographica. Section C, Structural Chemistry》2016,72(7):593-599
Several conditions need to be fulfilled for a photochemical reaction to proceed in crystals. Some of these conditions, for example, geometrical conditions, depend on the particular type of photochemical reaction, but the rest are common for all reactions. The mutual directionality of two neighbouring molecules determines the kind of product obtained. The influence of temperature on the probability of a photochemical reaction occurring varies for different types of photochemical reaction and different compounds. High pressure imposed on crystals also has a big influence on the free space and the reaction cavity. The wavelength of the applied UV light is another factor which can initiate a reaction and sometimes determine the structure of a product. It is possible, to a certain degree, to control the packing of molecules in stacks by using fluoro substituents on benzene rings. The crystal and molecular structure of 2,6‐difluorocinnamic acid [systematic name: 3‐(2,6‐difluorophenyl)prop‐2‐enoic acid], C9H6F2O2, (I), was determined and analysed in terms of a photochemical [2 + 2] dimerization. The molecules are arranged in stacks along the a axis and the values of the intermolecular geometrical parameters indicate that they may undergo this photochemical reaction. The reaction was carried out in situ and the changes of the unit‐cell parameters during crystal irradiation by a UV beam were monitored. The values of the unit‐cell parameters change in a different manner, viz. cell length a after an initial increase starts to decrease, b after a decrease starts to increase, c increases and the unit‐cell volume V after a certain increase starts to decrease. The structure of a partially reacted crystal, i.e. containing both the reactant and the product, namely 2,6‐difluorocinnamic acid–3,4‐bis(2,6‐difluorophenyl)cyclobutane‐1,2‐dicarboxylic acid (0.858/0.071), 0.858C9H6F2O2·0.071C18H12F4O4, obtained in situ, is also presented. The powder of compound (I) was irradiated with UV light and afterwards crystallized [as 3,4‐bis(2,6‐difluorophenyl)cyclobutane‐1,2‐dicarboxylic acid toluene hemisolvate, C18H12F4O4·0.5C7H8] in a space group different from that of the crystal containing the in‐situ dimer. 相似文献
996.
997.
998.
A series of Schiff bases 2[n] with n = 4, 6, 8, 10, 12, and 18 was prepared by the condensation of 9,9'-diaminobis(tricarbollide)Fe(II) (1b) with appropriate 4-alkoxybenzaldehydes (3[n]). Thermal analysis showed that they form nematic and smectic phases with clearing temperatures above 200 degrees C. Comparative studies of series 2[n] and its organic analogs demonstrated that the effectiveness of bis(tricarbollide)Fe(II) in supporting liquid crystalline phases is between that of benzene and biphenyl for n < or = 18 and lower than that of benzene for n = infinity. The photophysical properties were investigated for the butoxy derivative 2[4] and modeled using ZINDO calculations. 相似文献
999.
The interaction of CrII with taurine/alpha-ketoglutarate (alphaKG) dioxygenase (TauD) was examined. CrII replaces FeII and binds stoichiometrically with alphaKG to the FeII/alphaKG binding site of the protein, with additional CrII used to generate a chromophore attributed to a CrIII-semiquinone in a small percentage of the sample. Formation of the latter oxygen-sensitive species requires the dihydroxyphenylalanine (DOPA) quinone form of Tyr-73. This preformed side chain is generated by intracellular self-hydroxylation of Tyr-73 to form DOPA, which is subsequently oxidized to the quinone. No chromophore is generated when using NaBH4-treated sample, protein isolated from anaerobically grown cells, inactive TauD variants that are incapable of self-hydroxylation, or the Y73F active mutant of TauD. A CrIII-DOPA semiquinone also was observed in the herbicide hydroxylase SdpA. 相似文献
1000.
Setny P 《The Journal of chemical physics》2007,127(5):054505
We consider model systems consisting of a methane molecule and hemispherical pockets of subnanometer radii whose walls are made of hydrophobic material. The potential of mean force for process of translocation of the methane molecule from bulk water into the pockets' interior is obtained, based on an explicit solvent molecular dynamics simulations. Accompanying changes in water density around the interacting objects and spatial distribution of solvent's potential energy are analyzed, allowing for interpretation of details of hydrophobic interactions in relation to hydrophobic hydration properties. Applicability of surface area-based models of hydrophobic effect for systems of interest is also investigated. A total work for the translocation process is not dependent on pocket's size, indicating that pocket desolvation has little contribution to free energy changes, which is consistent with the observation that solvent density is significantly reduced inside "unperturbed" pockets. Substantial solvent effects are shown to have a longer range than in case of a well investigated methane pair. A desolvation barrier is present in a smaller pocket system but disappears in the larger one, suggesting that a form of a "hydrophobic collapse" is observed. 相似文献