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71.
Goveia D Rosa AH Bellin IC Lobo FA Fraceto LF Roveda JA Romão LP Dias Filho NL 《Analytical and bioanalytical chemistry》2008,390(4):1173-1180
This work involved the development and application of a new analytical procedure for in-situ characterization of the lability
of metal species in aquatic systems by using a system equipped with a diffusion membrane and cellulose organomodified with
p-aminobenzoic acid groups (DM-Cell-PAB). To this end, the DM-Cell-PAB system was prepared by adding cellulose organomodified
with p-aminobenzoic acid groups (Cell-PAB) to pre-purified cellulose bags. After the DM-Cell-PAB system was sealed, it was examined
in the laboratory. The in-situ application involved immersing the DM-Cell-PAB system in two different rivers, enabling us
to study the relative lability of metal species (Cu, Cd, Fe, Mn, and Ni) as a function of time and quantity of exchanger.
The procedure is simple and opens up a new perspective for understanding environmental phenomena relating to the complexation,
transport, stability, and lability of metal species in aquatic systems rich in organic matter. 相似文献
72.
Corr SA Byrne SJ Tekoriute R Meledandri CJ Brougham DF Lynch M Kerskens C O'Dwyer L Gun'ko YK 《Journal of the American Chemical Society》2008,130(13):4214-4215
Using a one-step procedure we have prepared magnetic fluids comprising of polyelectrolyte stabilized magnetite nanoparticles. These nanocomposites are comprised of linear, chain-like assemblies of magnetic nanoparticles, which can be aligned in parallel arrays by an external magnetic field. We have shown the potential use of these materials as contrast agents by measuring their MR response in live rats. The new magnetic fluids have demonstrated good biocompatibility and potential for in vivo MRI diagnostics. 相似文献
73.
Gautier A Juillerat A Heinis C Corrêa IR Kindermann M Beaufils F Johnsson K 《Chemistry & biology》2008,15(2):128-136
The visualization of complex cellular processes involving multiple proteins requires the use of spectroscopically distinguishable fluorescent reporters. We have previously introduced the SNAP-tag as a general tool for the specific labeling of SNAP-tag fusion proteins in living cells. The SNAP-tag is derived from the human DNA repair protein O6-alkylguanine-DNA alkyltransferase (AGT) and can be covalently labeled in living cells using O6-benzylguanine derivatives bearing a chemical probe. Here we report the generation of an AGT-based tag, named CLIP-tag, which reacts specifically with O2-benzylcytosine derivatives. Because SNAP-tag and CLIP-tag possess orthogonal substrate specificities, SNAP and CLIP fusion proteins can be labeled simultaneously and specifically with different molecular probes in living cells. We furthermore show simultaneous pulse-chase experiments to visualize different generations of two different proteins in one sample. 相似文献
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77.
Soares Iara Pereira da Silva Amanda Gonçalves da Fonseca Alves Rafael de Souza Corrêa Ricardo Augusto Moreira Ferreira Lucas Franco Franco Diego Leoni 《Journal of Solid State Electrochemistry》2019,23(3):985-995
Journal of Solid State Electrochemistry - In this paper, we investigated a novel functionalized polymeric film derived from 4-mercaptophenylacetic acid (MPAA). The polymerization was carried out... 相似文献
78.
Nanci C. de Lucas Mônica M. Elias Caio L. Firme Rodrigo J. Corrêa Simon J. Garden José Carlos Netto-Ferreira David E. Nicodem 《Journal of photochemistry and photobiology. A, Chemistry》2009,201(1):1-7
The photochemical hydrogen abstraction reaction of pyrene-4,5-dione (3) has been investigated by laser flash photolysis. Excitation (λ = 355 nm) of a degassed solution of 3 in acetonitrile resulted in the formation of a detectable transient with absorption maxima at 380 and 470 nm. This transient decays with a lifetime of around 4.8 μs and is quenched by oxygen. This transient is most probably a triplet state of 3. Addition of hydrogen donors, such as 2-propanol; 1,4-cyclohexadiene or 4-methoxyphenol led to the formation of a new transient with λmax at 380, 500 nm and a broad absorption at 640 nm. This new transient slowly decays with second order kinetics and was assigned to the semiquinone radical obtained from the hydrogen abstraction reaction. Using DFT and AIM calculations the reactivity of 3 and 9,10-phenanthrenequinone (1) is best interpreted as a proton coupled electron transfer like mechanism for the hydrogen abstraction from 2-propanol. 相似文献
79.
Antônio C. Doriguetto Rodrigo S. Corrêa Fernanda A. Siqueira Luiz F. Silva Jr. Javier Ellena 《Structural chemistry》2009,20(5):795-800
This paper presents the structural characterization of the indan derivative (±)-1-trans-3-(3,4-dichlorophenyl)-2,3-dihydro-1H-indene-1-carboxamide, which was unambiguously determined by X-ray diffraction (XRD) to be a racemate (R/S: 50/50) crystallizing in an achiral crystal structure (P21/c, a = 9.3180(1) Å, b = 7.9070(2) Å, c = 19.7550(4) Å, β = 103.250(1)°, V = 1416.75(5) Å3 and Z = 4). The diastereomers are related by the inversion symmetry and linked by H bond forming a dimer. The crystal packing is stabilized by hydrogen bonds, including the classical one responsible for the formation of centrosymmetric dimers, and non-classical ones involving C–H···O and C–H···π-aryl interactions. The intra and intermolecular geometry of the title compound is compared to the (±)-1-trans-3-(3,4-dichlorophenyl)-2,3-dihydro-1H-indene-1-carboxylic acid one, which also present an achiral crystal structure from racemates (R/S: 50/50). The two indan derivatives crystallize in a very similar unit cell. 相似文献
80.
Ruy Alberto Pisani Altafim Ruy Alberto Corrêa Altafim Xunlin Qiu Sebastian Raabe Werner Wirges Heitor Cury Basso Reimund Gerhard 《Applied Physics A: Materials Science & Processing》2012,107(4):965-970
Ferro- or piezoelectrets are dielectric materials with two elastically very different macroscopic phases and electrically charged interfaces between them. One of the newer piezoelectret variants is a system of two fluoroethylenepropylene (FEP) films that are first laminated around a polytetrafluoroethylene (PTFE) template. Then, by removing the PTFE template, a two-layer FEP structure with open tubular channels is obtained. After electrical charging, the channels form easily deformable macroscopic electric dipoles whose changes under mechanical or electrical stress lead to significant direct or inverse piezoelectricity, respectively. Here, different PTFE templates are employed to generate channel geometries that vary in height or width. It is shown that the control of the channel geometry allows a direct adjustment of the resonance frequencies in the tubular-channel piezoelectrets. By combining several different channel widths in a single ferroelectret, it is possible to obtain multiple resonance peaks that may lead to a rather flat frequency-response region of the transducer material. A phenomenological relation between the resonance frequency and the geometrical parameters of a tubular channel is also presented. This relation may help to design piezoelectrets with a specific frequency response. 相似文献