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991.
992.
993.
Roy Pöllänen Teemu Siiskonen Sakari Ihantola Harri Toivonen Andreas Pelikan Kenneth Inn Jerome La Rosa Balazs Bene 《Journal of Radioanalytical and Nuclear Chemistry》2011,290(3):551-555
High-resolution alpha spectrometry was applied for the activity determination of 10 reference sources containing different
amounts of 238Pu, 239Pu, 240Pu and 242Pu. They were analyzed as blind sources using a novel spectrum analysis tool ADAM. The information needed in the spectrum
unfolding was taken only from the spectrum under investigation, and no tracers were applied. Therefore, a Monte Carlo program
AASI was used to compute geometrical detection efficiency of the measurement setup. All reported activities corresponded to
those of the reference sources within expanded uncertainty. The developed tools can be used for the activity determination
in nondestructive alpha spectrometry or when the radionuclide composition does not change during the sample processing. 相似文献
994.
Crystallization kinetics and morphology of poly(lactic acid) with polysaccharide as nucleating agent
Dartora Paula Cristina da Rosa Loureiro Mariane de Camargo Forte Maria Madalena 《Journal of Thermal Analysis and Calorimetry》2018,134(3):1705-1713
Journal of Thermal Analysis and Calorimetry - An ever-increasing concern about environmental pollution has spearheaded research into alternative biodegradable polymers. Currently, poly(lactic acid)... 相似文献
995.
996.
How a Small Structural Difference Can Turn Optical Properties of π‐Extended Coumarins Upside Down: The Role of Non‐Innocent Saturated Rings
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Dr. Barbara Ventura Dr. Yevgen M. Poronik Dr. Irena Deperasińska Prof. Daniel T. Gryko 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(43):15380-15388
The fluorescence properties of two new families of heterocycles possessing either a seven‐ or five‐membered ring attached at the core molecule are entirely different in solution and in the solid state. Crystallization has the effect of inhibiting non‐radiative excited‐state deactivation pathways, operative in solution for the seven‐membered ring compounds, thus leading to significant fluorescence efficiency in the solid state, with quantum yields ranging from 0.10 to 0.36. Conversely, the five‐membered ring derivatives, which display notable emission properties in solution, are almost non‐emissive in the crystalline state, characterized by a long‐range π‐stacked arrangement. When embedded in polymeric films, both series show fluorescence features similar to the solution case, with remarkable fluorescence quantum yields ranging from 0.09 to 0.41. According to quantum chemical calculations, 3H‐chromeno[3,4‐c]pyridine‐4,5‐diones show the specific mechanism of fluorescence quenching. The derivatives bearing the seven‐membered ring undergo, in solution, a significant structural deformation in the excited state, resulting in a large decrease of the energy gap between S1 and S0 and hence to a substantial contribution of the internal conversion in the relaxation process. The fluorescence quenching of the five‐membered ring derivatives is in turn related to the intermolecular interaction between adjacent molecules prevailing to a greater extent in the crystal lattice. 相似文献
997.
A Semisynthetic Approach to New Immunoadjuvant Candidates: Site‐Selective Chemical Manipulation of Escherichia coli Monophosphoryl Lipid A
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Dr. Daniele D'Alonzo Manuela Cipolletti Giulia Tarantino Marcello Ziaco Dr. Giuseppina Pieretti Prof. Alfonso Iadonisi Prof. Giovanni Palumbo Dr. Alberto Alfano Dr. Mariateresa Giuliano Prof. Mario De Rosa Prof. Chiara Schiraldi Dr. Marcella Cammarota Prof. Michelangelo Parrilli Dr. Emiliano Bedini Prof. Maria M. Corsaro 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(31):11053-11063
A semisynthetic approach to novel lipid A derivatives from Escherichia coli (E. coli) lipid A is reported. This methodology stands as an alternative to common approaches based exclusively on either total synthesis or extraction from bacterial sources. It relies upon the purification of the lipid A fraction from fed‐batch fermentation of E. coli, followed by its structural modification through tailored, site‐selective chemical reactions. In particular, modification of the lipid pattern and functionalization of the phosphate group as well as of the sole primary hydroxyl group were accomplished, highlighting the unusual reactivity of the molecule. Preliminary investigations of the immunostimulating activity of the new semisynthetic lipid A derivatives show that some of them stand out as promising, new immunoadjuvant candidates. 相似文献
998.
1,2,3‐Triazole Bridge as Conformational Constrain in β‐Hairpin Peptides: Analysis of Hydrogen‐Bonded Positions
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Dr. V. Celentano Dr. D. Diana C. Di Salvo Dr. L. De Rosa Dr. A. Romanelli Prof. R. Fattorusso Dr. L. D. D'Andrea 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(16):5534-5537
Conformational constrained β‐hairpin peptides are useful tool to modulate protein–protein interactions. A triazole bridge in hydrogen‐bonded positions between two antiparallel strands induces a conformational stabilization of the β‐hairpin peptide. The entity of the stability of the β‐hairpin peptide depends on the length of the bridge. 相似文献
999.
Dr. Pablo Labra-Vázquez Ricardo Flores-Cruz Aylin Galindo-Hernández Dr. Justo Cabrera-González Cristian Guzmán-Cedillo Dr. Arturo Jiménez-Sánchez Dr. Pascal G. Lacroix Dr. Rosa Santillan Dr. Norberto Farfán Dr. Rosario Núñez 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(69):16530-16540
A set of BODIPY-carboranyl dyads synthesized by a Sonogashira cross-coupling reaction, where different C-substituted ortho- and meta-carboranyl fragments have been linked to a BODIPY fluorophore is described. Chemical, photophysical and physicochemical analyses are presented, including NMR and single XRD experiments, optical absorption/emission studies and partition coefficient (log P) measurements. These studies, supported by DFT computations (M06-2X/6-31G**), provide an explanation to the largely divergent cell income that these fluorescent carboranyl-based fluorophores display, for which a structural or physicochemical explanation remains elusive. By studying the cell uptake efficiency and subcellular localization for our set of dyads on living HeLa cells, we tracked the origins of these differences to significant variations in their static dipole moments and partition coefficients, which tune their ability to interact with lipophilic microenvironments in cells. Remarkably, m-carboranyl-BODIPY derivatives with a higher lipophilicity are much better internalised by cells than their homologous with o-carborane, suggesting that m-isomers are potentially better theranostic agents for in vitro bioimaging and boron carriers for boron neutron capture therapy. 相似文献
1000.
Liquid chromatography/mass spectrometry identification of intermediates and vulcanization products by using squalene as vulcanization model compound
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