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121.
Oncel N van Houselt A Huijben J Hallbäck AS Gurlu O Zandvliet HJ Poelsema B 《Physical review letters》2005,95(11):116801
The existence of one-dimensional (1D) electronic states between self-organized Pt nanowires spaced 1.6 or 2.4 nm apart on a Ge(001) surface is revealed by low-temperature scanning tunneling microscopy. These perfectly straight Pt nanowires act as barriers for a surface state (located just below the Fermi level) of the underlying terrace. The energy positions of the 1D electronic states are in good agreement with the energy levels of a quantum particle in a well. Spatial maps of the differential conductivity of the 1D electronic states conclusively reveal that these states are exclusively present in the troughs between the Pt nanowires. 相似文献
122.
Oncel N Hallback AS Zandvliet HJ Speets EA Ravoo BJ Reinhoudt DN Poelsema B 《The Journal of chemical physics》2005,123(4):044703
Single-electron tunneling through Au substrate-alkanethiol-Pd cluster-tip junctions is investigated with scanning tunneling spectroscopy. The measured I(V) curves reveal several characteristic features of the Coulomb blockade, namely, the presence of a Coulomb gap and a Coulomb staircase. By using the orthodox theory of single-electron tunneling, the capacitances and resistances of the double junction system as well as the fractional charge are extracted from the experimental data. 相似文献
123.
We have investigated the structure and energies of lithium microclusters containing 3-10 atoms in the fcc(100) and fcc(110) surface symmetries, and the interaction of an oxygen and hydrogen atom with these lithium microclusters for the on-top, open and bridge sites approaches. The calculations have been performed with molecular dynamics simulation methods (MDSM) at 1 K temperature and the results were compared with the literature. 相似文献
124.
Nuri Ünal 《Foundations of Physics》1998,28(5):755-762
Barut's classical model of the spinning particle having external dynamical variables x and p and internal dynamical variables
and z is taken into account. The path integrations over holomorphic spinors
and z are discussed. This quantization gives the kernel of the relativistic particles with higher spin as well as the Dirac electron. The Green's function of the spin-n/2 particle is obtained. 相似文献
125.
Meliha Burcu Gürdere Ali Cemal Emeç Osman Nuri Aslan Yakup Budak Mustafa Ceylan 《合成通讯》2016,46(6):536-545
The triethylamin-mediated addition of 2-aminoethanethiol hydrochloride to chalcone analogs was investigated. This addition, bearing a 2-thienyl group at the 3-position, gave the only addition adduct at room temperature in 3 h, whereas the chalcones bearing the 2-furyl group at the 1-position gave an addition-cyclization product (1, 4-thiazepine) in the same conditions. The effect of the groups to the reaction was investigated by changing the 1- and 3-position groups. The chalcones bearing the 2-thienyl group at the 1-position and the others afforded the mixture of products in different ratio at rt for 0.5–24 h. Moreover, the addition–cyclization products (1,4-thiazepine) were obtained under reflux conditions in 36 h. The structures of the synthesized compounds were elucidated by 1H NMR, 13C NMR, infrared, and elemental analysis. 相似文献
126.
A new fluorescent chemosensor (Bodipy-S) derived from Bodipy and Salophen was developed. After the characterization of all compounds, the behavior of the chemosensor Bodipy-S toward p, d and f block-metal ions was investigated by UV-vis and fluorescence spectroscopy. This chemosensor can selectively detect to Cu (II) in methanol-aqueous solution based on chelation enhanced fluorescence (CHEF) and it almost exhibit to a fluorescence quenching effect with 20-fold. The binding constant of the fluorophore was interpreted by using of the Stern-Volmer method and the complex stoichiometry was defined by using Job’s plot. Moreover, the effect of pH was performed by the fluorescence intensities of Bodipy-S in presence of Cu(II) ions. The chemosensor can be successfully used to the detection of Cu(II) in most areas. 相似文献
127.
L. A. Aksel’rod G. P. Gordeev V. N. Zabenkin I. M. Lazebnik V. Wagner H. Eckerlebe 《Crystallography Reports》2007,52(3):403-406
Investigation of the magnetic structure of the diluted (Pd0.984Fe0.016)0.95Mn0.05 alloy at meso-and nanoscale levels by means of two techniques of small-angle polarized-neutron scattering (within a direct beam and beyond it) has been performed in the temperature range 10<T<60 K. The dependences of the neutron beam depolarization, the polarization rotation angle, and the polarization-dependent magnetic scattering cross section on a weak (0<H<40 A/cm) external magnetic field have been studied. A simple model of neutron beam depolarization by a sample with uniaxial magnetic anisotropy was used to analyze the results obtained. The experiment on polarized-neutron scattering in the so-called direct geometry showed the existence of a polarization-dependent scattering cross section. This scattering has left-right asymmetry and depends on temperature. Comparison of these results with the depolarization data leads to a conclusion about the existence of static chiral fluctuations in large-scale inhomogeneities. 相似文献
128.
The title compound, bis[2-[N-(2-chlorophenyl)formimidayl]-1-naphtholato]-(6Cl) copper(II), [Cu(C17H11NOCl)2] (1) was synthesized and its crystal structure was determined. The Compound 1 is monoclinic, space group P2 1/c with a = 9.146(3) Å, b = 18.724(3) Å, c = 16.230(2) Å, β = 96.46(1)°, V = 2761.8(11) Å3, Z = 4, D c = 1.503 g cm?3, μ(Mo Kα) = 1.020 mm?1, R = 0.0606 for 2361 reflections [I > 2σ(I)]. In the title compound, the Cu atom is coordinated by an N2O2 donor set from the imine-phenol ligand in a slightly distorted square planar coordination geometry, with the two phenolate O atoms being deprotonated. The Cu–O bond lengths are 1.878(4) and 1.889(4) Å, the Cu–N bond lengths are 1.980(5) and 1.985(5) Å. The angles O1–Cu–N1 and O2–Cu–N2 are 90.96(19) and 90.72(19)°, respectively. 相似文献
129.
Leila O. Khafizova Nuri M. Chobanov Mariya G. Shaibakova Natalya R. Popodko Tatyana V. Tyumkina Usein M. Dzhemilev 《Tetrahedron》2018,74(20):2482-2487
An original method for the synthesis of С5-С6 cyclic ketones and tetrasubstituted furans was developed based on the Cp2TiCl2-catalyzed reaction of symmetrical alkynes and α,ω-dicarboxylates in the presence of Mg and ЕtAlCl2. The length of the hydrocarbon chain between carboxyl groups in a,ω-dicarboxylic acid esters affects the chemoselectivity of the reaction. The formation of 2-alkylidene and 2-alkenyl cyclopent(hex)an-1-ones occurred in the reaction with esters of glutaric and adipic acids. α,ω-Dicarboxylic acid esters with more than four methylene units between carboxyl groups gave rise to substituted furans. Stereochemistry of 2-alkenyl cyclopent(hex)an-1-ones was determined based on the analysis of experimental and theoretical data obtained from DFT calculations. 相似文献
130.
Rachel R. Ogorzalek Loo Richard Hayes Yanan Yang Frank Hung Prasanna Ramachandran Nuri Kim Robert Gunsalus Joseph A. Loo 《International journal of mass spectrometry》2005,240(3):317
Intact protein masses can be measured directly from immobilized pH gradient (IPG) isoelectric focusing (IEF) gels loaded with mammalian and prokaryotic samples, as demonstrated here with murine macrophage and Methanosarcina acetivorans cell lysates. Mass accuracy and resolution is improved by employing instruments which decouple the desorption event from mass measurement; e.g., quadrupole time-of-flight instruments. MALDI in-source dissociation (ISD) is discussed as a means to pursue top-down sequencing for protein identification. Methods have been developed to enzymatically digest all proteins in an IEF gel simultaneously, leaving the polyacrylamide gel attached to its polyester support. By retaining all gel pieces and their placement relative to one another, sample handling and tracking are minimized, and comparison to 2-D gel images is facilitated. MALDI-MS and MS/MS can then be performed directly from dried, matrix-treated IPG strips following whole-gel trypsin digestion, bottom-up methodology. Side-to-side proteomics, highlighting the link between virtual and classical 2-D gel electrophoresis, is introduced to describe a method whereby intact masses are measured from one side (the IEF gel), while proteins are identified based on analyses performed from the other side (the SDS-PAGE gel). 相似文献