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101.
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Heinrich B Burrowes C Montoya E Kardasz B Girt E Song YY Sun Y Wu M 《Physical review letters》2011,107(6):066604
Spin injection across the ferrimagnetic insulator (YIG)/normal metal (Au) interface was studied by ferromagnetic resonance. The spin mixing conductance was determined by comparing the Gilbert damping in bare YIG films with those covered by a Au/Fe/Au structure. The Fe layer in Au/Fe/Au acted as a spin sink as displayed by an increased Gilbert damping parameter α compared to that in the bare YIG. In particular, for the 9.0 nm YIG/2.0 nm Au/4.3 nm Fe/6.1 nm Au structure, the YIG and Fe films were coupled by an interlayer exchange coupling, and the exchange coupled YIG exhibited an increased Gilbert damping compared to the bare YIG. This relationship between static and dynamic coupling provides direct evidence for spin pumping. The transfer of spin momentum across the YIG interface is surprisingly efficient with the spin mixing conductance g(↑↓) ? 1.2 × 10(14) cm(-2). 相似文献
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105.
On-line determination of 3,5,6-trichloro-2-pyridinol in human urine samples by surface plasmon resonance immunosensing 总被引:1,自引:0,他引:1
Mauriz E Calle A Manclús JJ Montoya A Lechuga LM 《Analytical and bioanalytical chemistry》2007,387(8):2757-2765
An immunochemical method for the analysis of 3,5,6-trichloro-2-pyridinol (TCP), a major urinary metabolite of chlorpyrifos,
is developed using a surface plasmon resonance (SPR)-based biosensor. The stability of the assay was assessed by covalently
linking the analyte derivative to a thin, gold-modified sensor surface. For optimization of analyte derivative immobilization,
sensor chips were activated via alkanethiol monolayers with terminal amine or carboxyl groups. Binding inhibition tests were
performed in untreated urine samples and compared to those obtained in distilled water and PBS was used as control. In all
cases, similar detection limits, at the micrograms per litre level (0.1–0.24 μg L−1), were attained for TCP assays independently of the dilution buffer. Reproducibility of measurements was studied throughout
more than 130 regeneration cycles, which allowed the repeated use of the same immunosensor surface without significant variation
of the SPR signal. All measurements were developed in real-time in only 10 min, using a SPR portable system. The device could
be applied as a valuable analytical method to both environmental screening and clinic diagnostics. 相似文献
106.
Noemí Montoya Pablo Pardo Antonio Doménech-Carbó Javier Alarcón 《Journal of Sol-Gel Science and Technology》2014,69(1):137-147
Cubic, tetragonal and monoclinic Gd-doped zirconia nanoparticles with nominal composition GdxZr1?xO2 in the range 0 ≤ x ≤ 0.2, were prepared by annealing dried gels of Gd-containing zirconia at temperatures over the range between 450 and 1,300 °C. The synthesized zirconia-based nanoparticles with increased gadolinium load were characterized by X-ray powder diffraction, infrared and Raman spectroscopies, and transmission electron microscopy. The stabilization of the crystalline forms of Gd-doped ZrO2 solid solutions depends on the amount of Gd dopant and the annealing temperature. For low Gd loads in GdxZr1?xO2 being x < 0.05, the tetragonal form is the single phase up to 1,100 °C, whereas the monoclinic is the crystalline form detected up to 1,300 °C. Within the range of compositions 0.05 ≤ x < 0.1, is the tetragonal the only stabilized zirconia crystalline structure over the whole range of temperature up to 1,300 °C. For higher Gd-contents, in the range 0.1 ≤ x ≤ 0.2, is the cubic zirconia form the only stable phase for the whole range of annealing temperatures. Solid-state electrochemistry of the gadolinium-doped zirconia performed by the voltammetry of microparticles approach allowed distinguishing different electrochemical answers of Gd cation associated with slightly different local coordination surrounding of cations. Enantioselective electrocatalytic effect of monoclinic Gd-doped ZrO2 on the oxidation of l-(+)-tartaric acid and d-(?)-tartaric was also studied. 相似文献
107.
Edwin de la Cruz Montoya Maxime J.-F. Guinel Carlos Rinaldi 《Colloid and polymer science》2014,292(5):1191-1198
Magnetic polymer colloids (MPCs) consisting of CoFe2O4 nanoparticles (NPs) embedded in a poly(methyl methacrylate) (PMMA) matrix were synthesized by magnetic miniemulsion polymerization. CoFe2O4 NPs were modified with 3-trimethoxysilylpropylmethacrylate and directly emulsified with different concentrations of sodium dodecyl sulfate under ultrasonication for subsequent miniemulsion polymerization. The average diameter of the CoFe2O4/PMMA spheres (about 200 nm) was controlled by varying the amount of surfactant. Thermogravimetric analysis indicated that the magnetic content was in the range of 44 to 73 %. Magnetic properties of the dispersions were investigated by measuring equilibrium magnetization curves and the dynamic magnetic susceptibility as a function of frequency. The MPCs were found to follow the Debye model for the dynamic magnetic susceptibility, with a characteristic time given by the rotational hydrodynamic resistance and thermal energy through the Stokes-Einstein relation. This demonstrates that the MPCs respond to applied magnetic fields by rotating. Due to their uniform size and high magnetic loading, these colloids may be suitable in a variety of applications, including nanoscale mechanical probes and actuators in complex fluids and biological systems. 相似文献
108.
This Letter describes how to determine the parameter of the chaotic Lorenz system used in a two-channel cryptosystem. First the geometrical properties of the Lorenz system are used to reduce the parameter search space. Second the parameters are exactly determined—directly from the ciphertext—through the minimization of the average jamming noise power created by the encryption process. 相似文献
109.
C. Gil A. Márquez R. Baños M. G. Montoya J. Gómez 《Journal of Global Optimization》2007,38(2):265-281
Real optimization problems often involve not one, but multiple objectives, usually in conflict. In single-objective optimization
there exists a global optimum, while in the multi-objective case no optimal solution is clearly defined but rather a set of
optimums, which constitute the so called Pareto-optimal front. Thus, the goal of multi-objective strategies is to generate
a set of non-dominated solutions as an approximation to this front. However, most problems of this kind cannot be solved exactly
because they have very large and highly complex search spaces. The objective of this work is to compare the performance of
a new hybrid method here proposed, with several well-known multi-objective evolutionary algorithms (MOEA). The main attraction
of these methods is the integration of selection and diversity maintenance. Since it is very difficult to describe exactly
what a good approximation is in terms of a number of criteria, the performance is quantified with adequate metrics that evaluate
the proximity to the global Pareto-front. In addition, this work is also one of the few empirical studies that solves three-objective
optimization problems using the concept of global Pareto-optimality. 相似文献
110.
P. Bedregal B. Torres M. Ubillús P. Mendoza E. Montoya 《Journal of Radioanalytical and Nuclear Chemistry》2008,278(3):801-806
The chemistry laboratory at the Peruvian Institute of Nuclear Energy (IPEN) has carried out a validation method for the samples
of siliceous composition. At least seven variables affecting the robustness of the results were initially identified, which
may interact simultaneously or individually. Conventional evaluation hereof would imply a massive number of analyses and a
far more effective approach for assessment of the robustness for these effects was found in the Youden-Steiner test, which
provides the necessary information by only eight analyses for each sample type. Three reference materials were used for evaluating
the effects of variations in sample mass, irradiation duration, standard mass, neutron flux, decay time, counting time and
counting distance. 相似文献