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Hermann P Hermelink A Lausch V Holland G Möller L Bannert N Naumann D 《The Analyst》2011,136(6):1148-1152
Tip-enhanced Raman spectroscopy (TERS) is a highly sensitive spectroscopic technique which combines the advantages of optical spectroscopy with the requirements needed for the characterization of biological nano-structures. In this study, TERS was used to investigate the applicability of this spectroscopic technique for the detection of different virus strains like avipoxvirus and adeno-associated virus. TERS spectra obtained from different particles of the same virus strain show variations in relative peak intensities and positions of most spectral features observed. These spectral variations were higher for the larger avipoxvirus particles (?≈350 nm) than for the smaller adeno-associated virus particles (?≈26 nm). 相似文献
44.
Mügge C Rothenburger C Beyer A Görls H Gabbiani C Casini A Michelucci E Landini I Nobili S Mini E Messori L Weigand W 《Dalton transactions (Cambridge, England : 2003)》2011,40(9):2006-2016
Twelve Pt(II) complexes with cis-PtP(2)S(2) pharmacophores (where P(2) refers to two monodentate or one bidentate phosphane ligand and S(2) is a dithiolato ligand) were prepared, characterized and evaluated as potential antiproliferative agents. The various compounds were first studied from the structural point of view; afterward, their solubility properties as well as their solution behaviour were analyzed in detail. Antiproliferative properties were specifically evaluated against A2780 human ovarian carcinoma cells, either resistant or sensitive to cisplatin. For comparison purposes similar studies were carried out on four parent cis-dichloro bisphosphane Pt(II)complexes. On the whole, the cis-PtP(2)S(2) compounds displayed significant antiproliferative properties while the cis-PtP(2)Cl(2) (cis-dichloro bisphosphane Pt(II)) compounds revealed quite poor biological performances. To gain further insight into the molecular mechanisms of these bisphosphane Pt(II) compounds, the reactions of selected complexes against the model protein cytochrome c were investigated by ESI-MS and their adduct formation explored. A relevant reactivity with cyt c was obtained only for cis-PtP(2)Cl(2) compounds, whereas cis-PtP(2)S(2) compounds turned out to be nearly unreactive. The obtained results are interpreted and discussed in the frame of the current knowledge of anticancer platinum compounds and their structure-activity-relationships. The observation of appreciable antiproliferative effects for the relatively inert cis-PtP(2)S(2) compounds strongly suggests that these compounds will undergo specific activation within the cellular environment. 相似文献
45.
Qin T Wiedemair W Nau S Trattnig R Sax S Winkler S Vollmer A Koch N Baumgarten M List EJ Müllen K 《Journal of the American Chemical Society》2011,133(5):1301-1303
We present a novel core-shell-surface multifunctional structure for dendrimers using a blue fluorescent pyrene core with triphenylene dendrons and triphenylamine surface groups. We find efficient excitation energy transfer from the triphenylene shell to the pyrene core, substantially enhancing the quantum yield in solution and the solid state (4-fold) compared to dendrimers without a core emitter, while TPA groups facilitate the hole capturing and injection ability in the device applications. With a luminance of up to 1400 cd/m(2), a saturated blue emission CIE(xy) = (0.15, 0.17) and high operational stability, these dendrimers belong to the best reported fluorescence-based blue-emitting organic molecules. 相似文献
46.
Pearson D Hienzsch A Wagner M Globisch D Reiter V Özden D Carell T 《Chemical communications (Cambridge, England)》2011,47(18):5196-5198
RNA nucleosides are often naturally modified into complex non-canonical structures with key biological functions. Here we report LC-MS quantification of the Ar(p) and Gr(p) 2'-ribosylated nucleosides in tRNA using deuterium labelled standards, and the first detection of Gr(p) in complex fungi. 相似文献
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Budischowsky David Zwirchmayr Nele Sophie Hosoya Takashi Bacher Markus Hettegger Hubert Potthast Antje Rosenau Thomas 《Cellulose (London, England)》2021,28(10):6051-6071
Cellulose - Chromophores, colored substances of rather high stability that reduce brightness, are present in all kinds of cellulosic products, such as pulp, fibers, aged cellulosic material, and... 相似文献
49.
Antje Schüle Winfried Rasemann Cordula Preue 《Particle & Particle Systems Characterization》1997,14(1):21-29
There are many applications of particle technology in which solid mixtures consisting of particles having the same chemical, mineralogical and physical properties are used. The particles are then distinguishable only by shape. The particle shape significantly influences the technological behaviour of the mixture and the properties of the materials produced. Therefore, mathematical procedures are necessary in order to determine the composition of such a mixture according to the proportions of certain particle shape classes. These classes are the respective components of the mixture. In this work, various statistical methods were tested to classify the particles by shape analysis. A two-component mixture of quartz and muscovite was used as a reference material. The results obtained by different theoretical methods were compared with each other. Alternative methods such as histogram fit and the EM algorithm provided better results than the conventional method of discriminant analysis, as expected. Because the statistical behaviour of the components can be estimated only using reference samples, a statistical error of about 5–10% depending on the respective sample size was met. However, this is a satisfactory result. It turned out that it is possible to conclude exclusively on the basis of the particle shape distribution about the composition of a mixture. The methodical knowledge obtained can be used in industrial applications such as the ceramic industry, the production of paints and the bulk solids technology. 相似文献
50.
Best V Gallun FJ Ihlefeld A Shinn-Cunningham BG 《The Journal of the Acoustical Society of America》2006,120(3):1506-1516
If spatial attention acts like a "spotlight," focusing on one location and excluding others, it may be advantageous to have all targets of interest within the same spatial region. This hypothesis was explored using a task where listeners reported keywords from two simultaneous talkers. In Experiment 1, the two talkers were placed symmetrically about the frontal midline with various angular separations. While there was a small performance improvement for moderate separations, the improvement decreased for larger separations. However, the dependency of the relative talker intensities on spatial configuration accounted for these effects. Experiment 2 tested whether spatial separation improved the intelligibility of each source, an effect that could counteract any degradation in performance as sources fell outside the spatial spotlight of attention. In this experiment, intelligibility of individual sources was equalized across configurations by adding masking noise. Under these conditions, the cost of divided listening (the drop in performance when reporting both messages compared to reporting just one) was smaller when the spatial separation was small. These results suggest that spatial separation enhances the intelligibility of individual sources in a competing pair but increases the cost associated with having to process both sources simultaneously, consistent with the attentional spotlight hypothesis. 相似文献