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1.
Bent Fuglede 《Communications in Mathematical Physics》1990,129(3):481-509
The integral of a function over then'th power of hyperbolicd-dimensional spaceH is decomposed into integration along each orbit under diagonal action onH
n of the isometry groupG onH, followed by integration over the orbit space, parametrized in terms of a complete set of invariants. The Jacobian entering in this last integral is expressed explicitly in terms of certain determinants. When viewingH as a half-hyperboloid in
d+1
,G is induced by the homogeneous Lorentz groupO
(1,d) acting on
d+1
. 相似文献
2.
A combined experimental and theoretical study of a model system of multifunctional unsaturated ketones, including ethyl vinyl ketone (EVK), 2-cyclohexen-1-one, and 5-hexen-2-one, on the Si(100)-2 x 1 and Ge(100)-2 x 1 surfaces was performed in order to probe the factors controlling the competition and selectivity of organic reactions on clean semiconductor surfaces. Multiple internal reflection infrared spectroscopy data and density functional theory calculations indicate that EVK and 2-cyclohexen-1-one undergo selective [4 + 2] hetero-Diels-Alder and [4 + 2] trans cycloaddition reactions on the Ge(100)-2 x 1 surface at room temperature. In contrast, on the Si(100)-2 x 1 surface, evidence is seen for significant ene and possibly [2 + 2] C=O cycloaddition side products. The greater selectivity of these compounds on Ge(100) versus Si(100) is explained by differences between the two surfaces in both thermodynamic factors and kinetic factors. With 5-hexen-2-one, for which [4 + 2] cycloaddition is not possible, a small [2 + 2] C=C cycloaddition product is observed on Ge(100) and possibly Si(100), even though the [2 + 2] C=C transition state is calculated to be the highest barrier reaction by several kilocalories per mole. The results suggest that, due to the high reactivity of clean semiconductor surfaces, thermodynamic selectivity and control will play important roles in their selective functionalization, favoring the use of Ge for selective attachment of multifunctional organics. 相似文献
3.
Bent Fuglede 《Potential Analysis》1992,1(4):355-371
The first property is a refinement of earlier results of Ch. de la Vallée Poussin, M. Brelot, and A. F. Grishin. Let w=u–v with u, v superharmonic on a suitable harmonic space (for example an open subset of R
n
), and let [w]=[u]–[v] denote the associated Riesz charge. If w0, and if E denotes the set of those points of at which the lim inf of w in thefine topology is 0, then the restriction of [w] to E is 0. Another property states that, if e denotes a polar subset of such that the fine lim inf of |w| at each point of e is finite, then the restriction of [w] to e is 0. 相似文献
4.
We employ a variables-in-common method for constructing multivariate Tweedie distributions, based on linear combinations of independent univariate Tweedie variables. The method lies on the convolution and scaling properties of the Tweedie laws, using the cumulant generating function for characterization of the distributions and correlation structure. The routine allows the equivalence between independence and zero correlation and gives a parametrization through given values of the mean vector and dispersion matrix, similarly to the Gaussian vector. Our approach leads to a matrix representation of multivariate Tweedie models, which permits the simulations of many known distributions, including Gaussian, Poisson, non-central gamma, gamma, and inverse Gaussian, both positively or negatively correlated. 相似文献
5.
Mark D. Noirot Elizabeth G. Bent Arlan D. Norman 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4):177-180
Abstract Reaction of the 1,3,2,4-diazadiphosphetidine, trans-[C6H5N(H)P(S)NC6H5]2 with LiR (R = Me, n-Bu) followed by treatment of the resulting dianions with Me3SiCl and Me3GeBr produced trans-[C6H5N(R)P(S)NC6H5]2(R = Me3Si, 2; Me3Ge, 3). Substitution occurs without cis-trans isomerization or significant cleavage of the 1,3,2,4-diazadiphosphetidine ring. 2 and 3 have been characterized by spectral (1H and 31P NMR, IR, and MS) and elemental analytical data. Analogous reactions involving Me3SnCl yield mixtures containing [C6H5N(SnMe3)P(S)NC6H5]2 which could not be isolated or completely characterized. 相似文献
6.
Jacobsen AM Halling-Sørensen B Ingerslev F Hansen SH 《Journal of chromatography. A》2004,1038(1-2):157-170
The veterinary antibacterial agents chlortetracycline (CTC), oxytetracycline (OTC), sulfadiazine (SDZ), erythromycin (ERY) and tylosin (TYL A, B, C and D) were extracted from soil using pressurized liquid extraction (PLE). Citric acid (pH 4.7) and methanol was used as extraction buffer, followed by tandem-solid-phase extraction (SPE) clean-up (SAX + HLB) for all compounds. For quantification two slightly different methods were employed using LC-MS-MS with MRM detection. The soil extraction method was validated using a loamy sand soil and a sandy soil, representing two typical Danish agricultural soils. Recoveries were 50-80% for the tetracyclines (CTC and OTC) and sulfadiazine (SDZ) and 60-100% for the macrolides (TYL and ERY). Limits of detection for the soil extraction method (LOD(soil)) were 0.6-5.6 microg kg(-1) soil for CTC and OTC, 0.9-2.9 microg kg(-1) soil for SDZ and 2.4-5.5 microg kg(-1) soil for TYL A and ERY. Furthermore, the method was applied to field samples taken from two agricultural fields fertilised with liquid manure containing CTC and TYL A. These results showed a decline in the content of antibacterial agents throughout the sampling period of 155 days from 10 to 15 microg CTC kg(-1) soil and 20-55 microg TYL A kg(-1) soil to below or near the LOD(soil) listed above. Finally, the method was applied to barley grains harvested from the fields. None of the antibacterial agents were measured in grain samples, but recoveries for spiked grain samples were similar to soil recoveries. 相似文献
7.
LetX=G/H be an affine symmetric space of Hermitian type. For modules in the analytic continuation of the scalar holomorphic discrete
series forG, we show existence and uniqueness (that is, a multiplicity one result) of imbeddings into functions onX. The corresponding intertwining operators are analyzed using our previous methods for discrete series. In a slightly less
explicit way, we also give the analogous results for the continuation of the general discrete series. 相似文献
8.
Gary D. Bent Ralph H. Bartram Angelo R. Rossi Peter J. Kemmey 《Journal of Physics and Chemistry of Solids》1979,40(7):493-502
The energies of the ground state and low-lying excited states of the N4? defect in KN3 have been calculated using ab initio techniques. A rectangular equilibrium geometry with dimensions X = 2.76 and Z = 2.47 a.u. and ground state symmetry of Γ4+ was determined by calculating N4? as a free radical. For this ground state the unpaired electron is in a π orbital which is consistent with the experimental hyperfine tensor only if one edge of the N4? radical is parallel to the c axis in KN3. These results were used to calculate the X2Γ4+ state of N4? in the crystal field of KN3, yielding an energy of ?217.899 Hartrees. The isotropic hyperfine constant was calculated to be a = 2.1 G and the components of the anisotropic hyperfine tensor as Bxx = ?3.4 G, Byy = 7.0 G and Bzz = ?3.6 G, in good agreement with experimental and INDO results. Several excited states were calculated for the N4? defect in KN3. When an estimate was made of the correlation energy, the transition energy of the X2Γ4+→A2Γ3? transition agreed well with the peak energy of the 780 nm absorption band which has been attributed to N4?. 相似文献
9.
Phipps RK Petersen BO Christensen KB Duus JØ Frisvad JC Larsen TO 《Organic letters》2004,6(20):3441-3443
[structure: see text] Hesseltin A 1, a novel compound of mixed polyketide-terpenoid origins was isolated from the filamentous fungus Penicillium hesseltinei. The structure and stereochemistry were determined from extensive one- and two-dimensional NMR and mass spectral data. 相似文献
10.
The ability of a developed capillary electrophoresis (CE) method for fast, efficient and reliable main component assay of ragaglitazar [NNC 61-0029/DRF(-)2725] has been demonstrated through documentation of the analytical performance and the results of a successful validation. The fast analysis time of around 1.2 min ensures a high analytical capacity, and the validation results show that the CE method is robust and gives reliable and precise results. The results from the validation of the CE method meet the acceptance criteria that are normally set for other main component assays such as high-performance liquid chromatography assays. 相似文献