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131.
Angel Bustamante Enrico Mattievich Helio S. de Amorim Ivo Vencato Máximo M. Silveira 《Hyperfine Interactions》2005,166(1-4):599-603
The crystal structure of synthetic ferrous hureaulite, Fe5 2+ (H2O)4(PO4H)2(PO4)2, was refined from single-crystal X-ray data. It is monoclinic, space group C2/c, with a=17.487(4), b=9.017(2), c=9.338(2) Å, β=96.27(3)°, V=1463.6(6) Å3, Z=4 and D calc=3.327 g/cm3. This end member of the hureaulite series was crystallized under distinctly acidic conditions, by a method that gives perfect crystals, large enough for X-ray single crystal studies. The main feature of the hureaulite structure is that it has an equal number of normal (PO4)3+ and acid (PO4H)2+ tetradentate groups. These are centered on Fe2+ atoms and share corners with edge-linked octahedra, forming pentamer units. The five Fe2+ atoms are distributed on three distinct sites in these units. This can be directly observed in the Mössbauer spectrum at 295 K, which contains three doublets whose relative intensities correspond to the 1:2:2 distributions of crystallographic sites. 相似文献
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133.
Enrico Sanjust Raffaello Pompei Antonio Rescigno Augusto Rinaldi Maoro Ballero 《Applied biochemistry and biotechnology》1991,31(3):223-235
Four species of Pleurotus were adapted to grow on olive milling wastewater, and in certain conditions produced high yield of fruit bodies. Some biochemical transformations were observed in the olive milling wastewater owing to the growth of Pleurotus. In particular, the fungi actively excreted large amounts of laccase in the medium, and at the same time the concentration of phenolics and other toxic compounds significantly decreased, as revealed by HPLC analysis and toxicity tests on standard cultures of human cell lines. 相似文献
134.
Many beautiful experiments have been addressed to test standard quantum mechanics against local realistic models. Even if a strong evidence favouring standard quantum mechanics is emerged, a conclusive experiment is still lacking, because of low detection efficiencies. Recently, experiments based on pseudoscalar mesons have been proposed as a way for obtaining a conclusive experiment. In this paper, we investigate if this result can effectively be obtained. Our conclusions, based on a careful analysis of the proposed set ups, are that this will not be possible due to intrinsic limitations of these kind of experiments. 相似文献
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137.
Enrico Bernardi 《Annali di Matematica Pura ed Applicata》1986,146(1):161-172
Summary We study a class of second order Fuchsian hyperbolic operators. The well-posedness of the Cauchy problem in a space of regular distributions is proved, together with results on the propagation of singularities of the solution. Moreover we give a representation formula for the distribution solutions of the homogeneous equation. 相似文献
138.
Enrico Bompiani 《Annali di Matematica Pura ed Applicata》1929,7(1):273-300
Sunto. Ogni elemento di 2o ordine di curva di una superficie (ad asintotiche distinte e non rettilinee) determina duequadriche asintotiche osculatrici. Gli elementi di 2o ordine tali che queste quadriche abbiano, in ogni punto della superficie, un contatto assegnato con una retta, conica o cubica
sghemba associata al punto appartengono alle curve integrali di equazioni differenziali del tipov″P
i
(v′)=P
i+3(v′) (i=1, 2) oveP
k
(v′) è un polinomio di gradok inv′=dv/du a coefficienti funzioni diu ev. Determinazione della configurazione geometrica a partire dall'equazione. 相似文献
139.
A fewest switches trajectory surface hopping algorithm based on linear response time-dependent density-functional theory is developed and implemented into the plane wave ab initio molecular dynamics package CPMD. A scheme to calculate nonadiabatic couplings using a multi determinantal approximation of the excited state wave function is introduced. The method is applied to the study of the photorelaxation of protonated formaldimine, a minimal model of the rhodopsin chromophore retinal. A good agreement of the structural and dynamic behavior is found with respect to state averaged multiconfiguration self consistent field based trajectory surface hopping. 相似文献
140.
Effect of the π Bridge and Acceptor on Intramolecular Charge Transfer in Push–Pull Cationic Chromophores: An Ultrafast Spectroscopic and TD‐DFT Computational Study
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Dr. Benedetta Carlotti Dr. Enrico Benassi Prof. Vincenzo Barone Dr. Giuseppe Consiglio Prof. Fausto Elisei Dr. Alessandra Mazzoli Prof. Anna Spalletti 《Chemphyschem》2015,16(7):1440-1450
Three (donor–π–acceptor)+ systems with a methyl pyridinium or quinolinium as the electron‐deficient group, a dimethyl amino as the electron‐donor group, and an ethylene or butadiene group as the spacer have been investigated in a joint spectroscopic and TD‐DFT computational study. A negative solvatochromism has been revealed in the absorption spectra, which implies a solution color change, and interpreted by considering the variation in the permanent dipole moment modulus and orientation upon photoexcitation. The fluorescence efficiency decreases upon increasing solvent polarity, in agreement with the excited‐state optimized geometries (planar in low‐polarity media and twisted in high‐polarity media). Femtosecond transient absorption has revealed the occurrence of a fast photoinduced intramolecular charge transfer (ICT) and the molecular factors that determine an efficient ICT. Considering the crucial role of the ICT in tuning the nonlinear optical (NLO) properties, these compounds can be considered promising NLO materials. 相似文献