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991.
The electronic states as well as interband and intraband electrooptical transitions are considered for the narrow gap InSb nanotube in the field of homogeneously charged ring. The problem is solved in the framework of the variational approach. The field of the charged ring is brought to the field of the modified one dimensional Coulomb-like potential. Physically appropriate wave functions are suggested for this potential and the intensities of the threshold frequencies of the electrooptical transitions are calculated.  相似文献   
992.
In this paper we provide a closed mathematical formulation of our previous results in the field of symbolic dynamics of unimodal maps. This being the case, we discuss the classical theory of applied symbolic dynamics for unimodal maps and its reinterpretation using Gray codes. This connection was previously emphasized but no explicit mathematical proof was provided. The work described in this paper not only contributes to the integration of the different interpretations of symbolic dynamics of unimodal maps, it also points out some inaccuracies that exist in previous works.  相似文献   
993.
994.
Compton scattering saline solution was researched. Firstly according to the Compton scattering theory the linear relationship between the concentration and the scattered photon counts was obtained. And then it was proved by Compton scattering experiments for some solutions. According to those experiments, it was found that the slope was decreased when the atomic number of the cation was increased for alkali metal chloride solutions and alkaline-earth metal chloride solutions. Based on those relationships, a new method was promoted with which to measure the concentration of saline solution untouched the measured solution.  相似文献   
995.
《Polyhedron》2005,24(16-17):2200-2204
In order to stabilize neutral radicals with curved surface π-system and to evaluate their π-spin structures, we recently reported design and synthesis of an oxoverdazyl derivative with corannulene as the first stable bowl-shaped neutral radical. Spectroscopic and theoretical studies revealed that appreciable amount of π-spin density is delocalized onto the corannulene moiety with most of the π-spin density localized on the oxoverdazyl moiety. In this study, we have designed and synthesized an iminonitroxide derivative with corannulene as a novel bowl-shaped neutral radical with a higher stability than the oxoverdazyl derivative with corannulene. ESR/ENDOR/TRIPLE spectroscopies and density functional theory calculations have shown that the π-spin delocalization onto the corannulene moiety is lower than that of the oxoverdazyl derivative with corannulene in the ground state. A degree of π-conjugation between the corannulene moiety and the iminonitroxide moiety has also been evaluated by UV–Vis measurements.  相似文献   
996.
采用动态蒙特卡洛方法研究了自吸附半柔性高分子及其自吸附半柔性高分子与纳米粒子组成的混合物的构象行为.自吸附半柔性高分子的构象行为的研究,结果显示通过自吸附参数和弯曲能使高分子从一个线团状构象转变成一个紧密螺绕环状构象.紧密螺绕环状构象的折叠过程分为三个阶段:(i)几个分立的螺绕环(ii)一个松散的螺绕环(iii)一个紧密螺绕环.自吸附半柔性高分子与纳米粒子组成的混合物的构象行为的研究,结果表明可以采用具有紧密螺绕环结构的高分子有效地调控纳米粒子的空间排列.另外观察到一个非常有趣的现象,纳米粒子排列成一个环形结构.  相似文献   
997.
This paper introduces a novel approach to eliminate stripe noise in infrared images. The differences between bias voltages in column readout circuit of uncooled infrared sensors result in strong stripe noise which changes slowly in time. The problem can be solved by estimating the bias of each column of infrared images and correcting infrared images with the estimated biases. The bias estimation is translated into an energy optimization problem in the paper. The optimization aims to minimize difference between neighboring columns of images. Our approach can be processed on a single image, or in a recursive way in order to significantly reduce the computation in one frame time. Our approach is compared to the state-of-the-art the stripe noise removal method using realistic infrared images, and the experimental results show the effectiveness and efficiencies of our proposed approach.  相似文献   
998.
The ultrasonic fractionation of milk fat in whole milk to fractions with distinct particle size distributions was demonstrated using a stage-based ultrasound-enhanced gravity separation protocol. Firstly, a single stage ultrasound gravity separation was characterised after various sonication durations (5–20 min) with a mass balance, where defined volume partitions were removed across the height of the separation vessel to determine the fat content and size distribution of fat droplets. Subsequent trials using ultrasound-enhanced gravity separation were carried out in three consecutive stages. Each stage consisted of 5 min sonication, with single and dual transducer configurations at 1 MHz and 2 MHz, followed by aliquot collection for particle size characterisation of the formed layers located at the bottom and top of the vessel. After each sonication stage, gentle removal of the separated fat layer located at the top was performed.Results indicated that ultrasound promoted the formation of a gradient of vertically increasing fat concentration and particle size across the height of the separation vessel, which became more pronounced with extended sonication time. Ultrasound-enhanced fractionation provided fat enriched fractions located at the top of the vessel of up to 13 ± 1% (w/v) with larger globules present in the particle size distributions. In contrast, semi-skim milk fractions located at the bottom of the vessel as low as 1.2 ± 0.01% (w/v) could be produced, containing proportionally smaller sized fat globules. Particle size differentiation was enhanced at higher ultrasound energy input (up to 347 W/L). In particular, dual transducer after three-stage operation at maximum energy input provided highest mean particle size differentiation with up to 0.9 μm reduction in the semi-skim fractions. Higher frequency ultrasound at 2 MHz was more effective in manipulating smaller sized fat globules retained in the later stages of skimming than 1 MHz. While 2 MHz ultrasound removed 59 ± 2% of the fat contained in the initial sample, only 47 ± 2% was removed with 1 MHz after 3 ultrasound-assisted fractionation stages.  相似文献   
999.
1000.
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