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141.
建立蝙蝠发声组织模型对超声机理研究及在智能设备的应用具有重要意义。根据蝙蝠喉部发声组织结构特点,通过有限元方法构建了蝙蝠的3种不同发声组织模型,分析了尺寸、材料力学参数、组织结构和张力4个因素对发声组织特征频率的影响。结果表明,如果用人类声带,按比例缩小构建蝙蝠喉部组织模型,蝙蝠无法发出超声波。构建组织结构含甲状软骨和声带的半鼓状模型和只含声带的条状模型,两种模型的特征频率相近且在合理的参数域内均无法达到超声范围。而含膜条状模型的特征频率可以通过张力进行超声频率的调节,这与文献的实验结果一致。因此,可基于含膜条状模型对蝙蝠喉管发声组织进行建模及其发声机理研究。 相似文献
142.
《Polyhedron》1987,6(11):1987-1991
Treatment of bis(dibenzylideneacetone)palladium with trimethylphosphine under a carbon monoxide atmosphere gives the title complex in good yield. X-ray crystallography has shown the structure of the complex to consist of an octahedron of palladium atoms which is bicapped by two further palladium atoms in an asymmetric fashion. Seven of the eight palladium centres carry terminal trimethylphosphine ligands. Two face-bridging and six edge-bridging CO molecules complete the ligand shell. 相似文献
143.
WEN De-Hua CHEN Wei LIU Liang-Gang 《理论物理通讯》2007,47(4):653-657
Properties and deformations of the rotating neutron stars in uniform strong magnetic field are calculated. The magnetic field will soften the equation of state of the neutron star matters and make an obvious effect on the structure of the rotating neutron star. If the magnetic field is superstrong (B=10^17 T), the mass, radius, and the deformation will become smaller effectively. 相似文献
144.
145.
《Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy》1986,42(2-3):285-298
The E → B transition of I2 in the region 4400-4000 Å has been studied under high resolution using a 7.3 m vacuum Ebert spectrograph in the 14th order. The values of the constants Be, αe, γe, De and βe of both E and B states determined from the analysis of the rotational structure of nine bands of the system are presented. Vibrational constants of the E state obtained from the analysis of all the bands so far reported and consistent with the precise constants of the B state given in previous work are also presented. The origin of the upper state, E(0+g), of the transition is discussed. 相似文献
146.
《Spectrochimica Acta Part B: Atomic Spectroscopy》1986,41(10):1089-1113
An improved, continuous-flow ultrasonic nebulizer equipped with a desolvation system for generating dehydrated aerosol particles prior to their injection into analytical inductively coupled plasmas is described. Results of a critical evaluation of the performance of the nebulizer-desolvation system are also presented. Compared to the commonly used pneumatic nebulizers studied in this work, the ultrasonic version described in this paper provided superior powers of detection, ranging from factors of 5–50, and yielded comparable to superior short and long term reproducibility for dilute acid and high salt content solutions. Clean out times for the ultrasonic nebulizer were marginally longer, by 15–20 s, than those observed for pneumatic nebulizers. “Memory effects” and “desolvation interferences” were generally reducible to negligible proportions through the application of various expediencies discussed in this paper. When substantial changes in concomitant concentrations caused measurable interelement effects, the magnitude of these effects tended to be slightly higher for the ultrasonic system. However, when the samples destined for ultrasonic nebulization were diluted by factors of ~ 10, which corresponds approximately to the superiority of the nebulization efficiency of the ultrasonic nebulizer, the magnitudes of the interelement effects were comparable. 相似文献
147.
148.
《Superlattices and Microstructures》1986,2(4):363-368
By repeated deposition of several Å of Ni below 100 °C and subsequent annealing to typically 350 °C, thin continuous NiSi2-layers have been grown epitaxially on Si (111). Thicknesses exceeding ∼- 70 Å require a different procedure due to the increasing importance of lateral growth, spoiling the layer quality. We show that MBE at substrate temperatures above 500 °C is not a viable technique to increase the thickness of the ultrathin layers. The reason is found to lie in the insufficient stability of the NiSi2 templates, disintegrating into islands at temperatures above 500 °C. Perfectly smooth layers up to 1000 Å have, however, been grown by a new method in which alternate layers of Ni and Si (typically 1 Å and 4 Å respectively) are deposited onto the initial template at substrate temperatures between 350 °C and 380 °C. 相似文献
149.
Leqing Lin Yu Zhong Haoyang Lin Chenglong Wang Zhifei Yang Qian Wu Di Zhang Wenguo Zhu Yongchun Zhong Yuwei Pan Jianhui Yu Huadan Zheng 《Molecules (Basel, Switzerland)》2022,27(13)
Spider silk is one of the hottest biomaterials researched currently, due to its excellent mechanical properties. This work reports a novel humidity sensing platform based on a spider silk-modified quartz tuning fork (SSM-QTF). Since spider silk is a kind of natural moisture-sensitive material, it does not demand additional sensitization. Quartz-enhanced conductance spectroscopy (QECS) was combined with the SSM-QTF to access humidity sensing sensitively. The results indicate that the resonance frequency of the SSM-QTF decreased monotonously with the ambient humidity. The detection sensitivity of the proposed SSM-QTF sensor was 12.7 ppm at 1 min. The SSM-QTF sensor showed good linearity of ~0.99. Using this sensor, we successfully measured the humidity of disposable medical masks for different periods of wearing time. The results showed that even a 20 min wearing time can lead to a >70% humidity in the mask enclosed space. It is suggested that a disposable medical mask should be changed <2 h. 相似文献
150.
A high-performance liquid chromatography-tandem mass spectrometry method was established for the simultaneous determination of mycophenolic acid, mycophenolate mofetil, tacrolimus, rapamycin, everolimus and pimecrolimus in human whole blood by optimizing the QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) preparation method. Whole blood was extracted into ethyl acetate, salted out with anhydrous magnesium sulfate, and purified with ethylenediamine-N-propyl silane adsorbent. The supernatant was evaporated under nitrogen until dry and finally reconstituted in methanol. Chromatographic separation was performed on an Agilent Poroshell 120 EC-C18 column in methanol (mobile phase A)-water (optimized for 0.1% acetic acid and 10 mM ammonium acetate, mobile phase B) at a 0.3 mL·min−1 flow rate. Electrospray ionization and positive ion multiple reaction monitoring were used for detection. The time for of analysis was 13 min. The calibration curves range of tacrolimus, rapamycin, everolimus and pimecrolimus were in the range of 1–100 ng·mL−1, mycophenolate mofetil in the range of 0.1–10 ng·mL−1 and mycophenolic acid at 10–1000 ng·mL−1. All correlation coefficients were >0.993. The coefficients of variation (CV, %) for inter-day and intra-day precision were less than 10%, while the spiked recoveries were in the range of 92.1% to 116%. Our method was rapid, sensitive, specific, and reproducible for the simultaneous determination of six immunosuppressants in human whole blood. Importantly, our approach can be used to monitor drug concentrations in the blood to facilitate disease treatment. 相似文献