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51.
Mateusz Kwitniewski Asta Juzeniene Li-Wei Ma Renata Glosnicka Alfreda Graczyk Johan Moan 《Journal of photochemistry and photobiology. B, Biology》2009,94(3):214-222
Photodynamic therapy (PDT) is an alternative treatment modality involving light activated drugs, called photosensitizers (PSs), to treat cancer and non-cancerous conditions. The search for new compounds which might become effective PSs is the major direction for PDT development. In the present work we have studied the dark toxicity, intracellular localization and photodynamic properties of four potential, water soluble, second generation PSs – PP(Arg)2, PP(Ser)2Arg2, PP(Ala)2Arg2, PP(Phe)2Arg2, all diamino acid derivatives of protoporphyrin IX. Human prostate cancer (DU-145) and squamous carcinoma (A431) cells were used as experimental model.Among investigated compounds PP(Ser)2Arg2 exhibited the lowest dark toxicity and the highest PDT effectiveness towards both cell lines. Fluorescence microscopy revealed the time-dependent changes in intracellular localization of the PS which were related to the phototoxicity. The results show that PP(Ser)2Arg2 may be a potential PS for PDT. 相似文献
52.
Mateusz Krzyzosiak Ryszard Gonczarek Adam Gonczarek Lucjan Jacak 《Frontiers of Physics》2016,11(6):117407
A framework for analytical studies of superconducting systems is presented and illustrated. The formalism, based on the conformal transformation of momentum space, allows one to study the effects of both the dispersion relation and the structure of the pairing interaction in two-dimensional anisotropic high-T c superconductors. In this method, the number of employed degrees of freedom coincides with the dimension of the momentum space, which is different compared to that in the standard Van Hove scenario with a single degree of freedom. A new function, the kernel of the density of states, is defined and its relation to the standard density of states is explained. The versatility of the method is illustrated by analyzing coexistence and competition between spin-singlet and spin-triplet order parameters in superconducting systems with a tight-binding-type dispersion relation and an anisotropic pairing potential. Phase diagrams of stable superconducting states in the coordinates η (the ratio of hopping parameters) and n (the carrier concentration) are presented and discussed. Moreover, the role of attractive and repulsive on-site interactions for the stability of the s-wave order parameter is explained. 相似文献
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Mateusz Maciejewski Paul N. Barlow Nico Tjandra 《Journal of computational chemistry》2014,35(7):518-525
In this study, we examine the feasibility and limitations of describing the motional behavior of three‐domain proteins in which the domains are linearly connected. In addition to attempting the determination of the internal and overall reorientational correlation times, we investigate the existence of correlations in the motions between the three domains. Since in linearly arranged three‐domain proteins, there are typically no experimental data that can directly report on motional correlation between the first and the third domain, we address this question by dynamics simulations. Two limiting cases occur: (1) for weak repulsive potentials and (2) when strong repulsive potentials are applied between sequential domains. The motions of the terminal domains become correlated in the case of strong interdomain repulsive potentials when these potentials do not allow the angle between the sequential domains to be smaller than about 60°. Using the model‐free (MF) and extended MF formalisms of Lipari and Szabo, we find that the motional behavior can be separated into two components; the first component represents the concerted overall motion of the three domains, and the second describes the independent component of the motion of each individual domain. We find that this division of the motional behavior of the protein is maintained only when their timescales are distinct and can be made when the angles between sequential domains remain between 60° and 160°. In this work, we identify and quantify interdomain motional correlations. © 2013 Wiley Periodicals, Inc. 相似文献
57.
Monika Gosecka Mateusz Gosecki Slawomir Kazmierski 《Journal of Polymer Science.Polymer Physics》2016,54(21):2171-2178
This article demonstrates the utility of DOSY NMR for the determination of the optimal conditions for the efficient covalent, reversible cross‐linking of macromolecules in water for hydrogel formation. The studied model system was hyperbranched polyglycidol (HbPGL) containing numerous diol groups in peripheral regions and two types of boronic acids, that is, B(OH)4? and benzene‐1,4‐boronic diacid, as cross‐linking agents. Diffusion coefficient changes of a polymer in solution, under the influence of various concentrations of cross‐linking agent and pH, which influences the equilibrium of the reaction between boronic acids and diols, were recorded. These data are consistent with the rheological properties, namely the G′max(ω) of hydrogels prepared under analogous conditions, from more concentrated solutions of HbPGL. This approach appears to be promising as it facilitates avoiding the loss of a large amount of polymer that is necessary for the elaboration of appropriate conditions for network formation in aqueous media. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 2171–2178 相似文献
58.
Ursula Niese W. Smulek M. Borkowski W. Helbig 《Journal of Radioanalytical and Nuclear Chemistry》1990,144(5):343-349
Low level alpha-spectrometry was applied for the determination of actinides separated from environmental samples. Interference free detection limits of 1.5–2.0 E-5 Bq at a counting interval of 150,000 sec and detection limits of the investigated samples of 0.05–0.005 Bq kg–1 were determined.Presented; Actinides-89, September 24–29, 1989, Taschkent, USSR. 相似文献
59.
Huczko A Bystrzejewski M Lange H Fabianowska A Cudziło S Panas A Szala M 《The journal of physical chemistry. B》2005,109(34):16244-16251
1-D nanostructures of cubic phase silicon carbide (beta-SiC) were efficiently produced by combustion synthesis of mixtures containing Si-containing compounds and halocarbons in a calorimetric bomb. The influence of the operating parameters on 1-D SiC formation yield was studied. The heat release, the heating rate, and the chamber pressure increase were monitored during the process. The composition and structural features of the products were characterized by elemental analysis, X-ray diffraction, differential thermal analysis/ thermogravimetric technique, Raman spectroscopy, scanning and transmission electron microscopy, and energy-dispersive X-ray spectrometry. This self-induced growth process can produce SiC nanofibers and nanotubes ca. 20-100 nm in diameter with the aspect ratio higher than 1000. Bulk scale Raman studies showed the product to be comprised of mostly cubic polytype of SiC and that finite size effects are present. We believe that the nucleation mechanism involving radical gaseous species is responsible for 1-D nanostructures growth. The present study has enlarged the family of nanofibers and nanotubes available and offers a possible, new general route to 1-D crystalline materials. 相似文献
60.
F. Borkowski G. G. Simon V. H. Walther R. D. Wendling 《Zeitschrift für Physik A Hadrons and Nuclei》1975,275(1):29-31
It is shown that the proton rms radius should be determined from fitting a polynomial of second order to the low-q 2 form factors. The commonly used polynomial of first order yields radius values which are too small. The proton rms radius has been redetermined from an analysis of the electron scattering data measured at three laboratories. The best fit value is 〈r E 2 〉1/2=0.87±0.02 fm. 相似文献