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131.
Boudalis AK Clemente-Juan JM Dahan F Psycharis V Raptopoulou CP Donnadieu B Sanakis Y Tuchagues JP 《Inorganic chemistry》2008,47(23):11314-11323
Complexes [Fe(Hhbi)(2)(NO(3))].2EtOH (1.2EtOH) and [Fe(2)(mu-OH)(2)(Hhbi)(4)].2H(2)O.8EtOH (2.2H(2)O.8EtOH) crystallize in the orthorhombic Fdd2 and P4(2)2(1)2 space groups, respectively (Hhbi(-) = the monoanion of 2-(2'-hydroxyphenyl benzimidazole). Complex 1 exhibits paramagnetic relaxation as evidenced by Mossbauer spectroscopy, and significant axial zero-field splitting (1.5 cm(1) 相似文献
132.
Beauvericin, a cyclohexadepsipeptide ionophore from the entomopathogen Beauveria bassiana, shows antibiotic, antifungal, insecticidal, and cancer cell antiproliferative and antihaptotactic (cell motility inhibitory) activity in vitro. The bbBeas gene encoding the BbBEAS nonribosomal peptide synthetase was isolated from B. bassiana and confirmed to be responsible for beauvericin biosynthesis by targeted disruption. BbBEAS utilizes D-2-hydroxyisovalerate (D-Hiv) and L-phenylalanine (Phe) for the iterative synthesis of a predicted N-methyl-dipeptidol intermediate, and forms the cyclic trimeric ester beauvericin from this intermediate in an unusual recursive process. Heterologous expression of the bbBeas gene in Escherichia coli to produce the 3189 amino acid, 351.9 kDa BbBEAS enzyme provided a strain proficient in beauvericin biosynthesis. Comparative infection assays with a BbBEAS knockout B. bassiana strain against three insect hosts revealed that beauvericin plays a highly significant but not indispensable role in virulence. 相似文献
133.
Noy A Pérez A Márquez M Luque FJ Orozco M 《Journal of the American Chemical Society》2005,127(13):4910-4920
Molecular dynamics is used to investigate the properties of the DNA.RNA hybrid in aqueous solution at room temperature. The structure of the hybrid is intermediate between A and B forms but, in general, closer to the canonical A-type helix. All the riboses exhibit North puckerings, while 2'-deoxyriboses exist in North, East, and South puckerings, the latter being the most populated one. The molecular recognition pattern of the DNA.RNA hybrid is a unique combination of those of normal DNA and RNA duplexes. Finally, the results obtained from essential dynamics and stiffness analysis demonstrate the large and very asymmetric flexibility of the hybrid and the strong predilection that each strand (DNA or RNA) has on the nature of their intrinsic motions in the corresponding homoduplexes. The implications of the unique structural and dynamic properties of the DNA.RNA hybrid on the mechanism of cleavage by RNase H are discussed. 相似文献
134.
Costes JP Shova S Juan JM Suet N 《Dalton transactions (Cambridge, England : 2003)》2005,(17):2830-2832
A cyclic tetranuclear [V(IV)O-Gd(III)](2) complex with VO and Gd ions alternately arrayed, behaves, from the magnetic point of view, as two independent dinuclear entities each having a S= 4 ground state, as a consequence of an active and ferromagnetic VO-Gd interaction through the double phenoxo bridge and a magnetically inactive VO-Gd interaction through the amide bridge. 相似文献
135.
Leonardo Modesto 《General Relativity and Gravitation》2005,37(1):207-213
In this paper we work in perturbative quantum gravity coupled to scalar matter at tree level and we introduce a new effective model in analogy with the Fermi theory of weak interaction and in relation with a previous work where we have studied only the gravity and its self-interaction. This is an extension of the I.T.B. model (Intermediate-Tensor-Boson) for gravity also to gravitationally interacting scalar matter. We show that in a particular gauge the infinite series of interactions containing n gravitons and two scalars could be rewritten in terms of only two Lagrangians containing a massive field, the graviton and, obviously, the scalar field. Using the S-matrix we obtain that the low energy limit of the amplitude reproduces the local Lagrangian for the scalar coupled to gravity. 相似文献
136.
For an atom in an externally driven cavity, we show that special initial states lead to near-disentangled atom-field evolution, and superpositions of these can lead to near maximally entangled states. Somewhat counterintutively, we find that (moderate) spontaneous emission in this system actually leads to a transient increase in entanglement beyond the steady-state value. We also show that a particular field correlation function could be used, in an experimental setting, to track the time evolution of this entanglement. 相似文献
137.
Let be a finite separable extension, , and the torsion subgroup of . When is an abelian extension is explicitly determined. This information is used to study the structure of . In particular, when am = a ∈ F is explicitly determined. 相似文献
138.
Mirtha Orozco Alberto Camacho Salvador Canzonieri 《Physics and Chemistry of Liquids》2018,56(3):353-362
Densities and viscosities of binary liquid mixtures of propyl propanoate + heptane and propyl propanoate + octane at temperatures of 278.15, 283.15, 288.15, 293.15, 298.15, 303.15, 308.15, 313.15, 318.15 and 323.15 K have been measured at atmospheric pressure over the entire range of composition. Using these experimental data, the excess molar volumes and the viscosity deviation have been calculated. The experimental data of density and viscosity at different investigated temperatures were mathematically represented by the Jouyban–Acree model. The mean relative deviation (MRD) was used as an error criterion, and the MRD values for data correlation of density and viscosity at different investigated temperatures are less than 0.03% and 0.50%, respectively. Excess molar volumes and viscosity deviations were correlated with Redlich–Kister equation. The calculated data point out the absence of speci?c interactions between the molecules of different components, which would be slightly weaker compared to the interactions in the pure components. 相似文献
139.
Orozco P. Maldonado S. Muñiz R. Equihua F. Luna S. Ortiz J. García A. Castruita L. Hernández A. 《Journal of Thermal Analysis and Calorimetry》2018,131(3):2329-2335
Journal of Thermal Analysis and Calorimetry - The aim of the present work was to study the effect of the α-Al2O3 and MgAl2O4 oxide films, normally found in cast aluminum alloys, on formation... 相似文献
140.
Carles Curutchet Modesto Orozco F. Javier Luque 《Journal of computational chemistry》2001,22(11):1180-1193
This study reports the parametrization of the HF/6‐31G(d) version of the MST continuum model for n‐octanol. Following our previous studies related to the MST parametrization for water, chloroform, and carbon tetrachloride, a detailed exploration of the definition of the solute/solvent interface has been performed. To this end, we have exploited the results obtained from free energy calculations coupled to Monte Carlo simulations, and those derived from the QM/MM analysis of solvent‐induced dipoles for selected solutes. The atomic hardness parameters have been determined by fitting to the experimental free energies of solvation in octanol. The final MST model is able to reproduce the experimental free energy of solvation for 62 compounds and the octanol/water partition coefficient (log Pow) for 75 compounds with a root‐mean‐square deviation of 0.6 kcal/mol and 0.4 (in units of log P), respectively. The model has been further verified by calculating the octanol/water partition coefficient for a set of 27 drugs, which were not considered in the parametrization set. A good agreement is found between predicted and experimental values of log Po/w, as noted in a root‐mean‐square deviation of 0.75 units of log P. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1180–1193, 2001 相似文献