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101.
为了提高超声喷丸强化加工的面积、效率及加工质量,对传统单振子超声喷丸强化技术进行了改进,提出了压电振子阵列型超声喷丸强化加工方法。分析了超声喷丸强化的机理,进行了压电振子的优化设计,分析了激振片的谐振响应,实验测试了系统样机在不同超声电源功率下弹丸撞击工件的区域分布;探究了超声电源功率、喷丸距离、弹丸直径和喷丸时间对加工样件显微硬度的影响,结果表明:以超声电源功率作为唯一变量,弹丸冲击工件表面的区域面积随超声电源功率增大而增大;7075铝合金样件的表面显微硬度及其提高率,随超声电源功率的增大、喷丸时间的增加、喷丸距离的减小及弹丸直径的增大而增大;超声电源功率为50W、喷丸时间为20min、喷丸距离为5mm、弹丸直径为1.5mm时喷丸效果最好,此时工件表面显微硬度增加量为65.1HV,表面显微硬度提高率为36.7%。压电振子阵列型超声喷丸强化技术可以有效增加喷丸冲击工件的面积,提高工件的表面显微硬度和加工效率。 相似文献
102.
Cristina Bena Smitha Vishveshwara Leon Balents Matthew P. A. Fisher 《Journal of statistical physics》2001,103(3-4):429-440
The Luttinger model of the one-dimensional Fermi gas is the cornerstone of modern understanding of interacting electrons in one dimension. In fact, the enormous class of systems whose universal behavior is adiabatically connected to it are now deemed Luttinger liquids. Recently, it has been shown that metallic single-walled carbon nanotubes are almost perfectly described by the Luttinger Hamiltonian. Indeed, strongly non-Fermi liquid behavior has been observed in a variety of DC transport experiments, in very good agreement with theoretical predictions. Here, we describe how fractional quasiparticle charge, a fundamental property of Luttinger liquids, can be observed in impurity-induced shot noise. 相似文献
103.
104.
R. A. Cottis 《Russian Journal of Electrochemistry》2006,42(5):497-505
The electrochemical noise method is reasonably well established as a technique that can estimate corrosion rate through the
electrochemical noise resistance or impedance. A more interesting potential application is the identification of the nature
of the corrosion process. In this paper, a number of corrosion types are examined, and it is concluded that the majority constitute
a form of shot noise, possibly with a superimposed baseline current. Methods by which parameters describing the shot noise
process can be estimated from the measured data are presented. It appears to be feasible to extract the charge in the shot
noise events, and their frequency, providing all of the anodic or cathodic current, is associated with these events. However,
the analysis requires a number of assumptions that are not always valid, and these are discussed. Finally, some alternative
methods that have been used to identify the type of corrosion are briefly discussed.
Published in Russian in Elektrokhimiya, 2006, Vol. 42, No. 5, pp. 557–566.
The text was submitted by the author in English. 相似文献
105.
106.
Huan Chen Shengliang Li Min Wu Kenry Zhongming Huang Chun‐Sing Lee Bin Liu 《Angewandte Chemie (International ed. in English)》2020,59(2):632-636
Traditional photosensitizers (PSs) show reduced singlet oxygen (1O2) production and quenched fluorescence upon aggregation in aqueous media, which greatly affect their efficiency in photodynamic therapy (PDT). Meanwhile, non‐targeting PSs generally yield low efficiency in antibacterial performance due to their short lifetimes and small effective working radii. Herein, a water‐dispersible membrane anchor (TBD‐anchor) PS with aggregation‐induced emission is designed and synthesized to generate 1O2 on the bacterial membrane. TBD‐anchor showed efficient antibacterial performance towards both Gram‐negative (Escherichia coli) and Gram‐positive bacteria (Staphylococcus aureus). Over 99.8 % killing efficiency was obtained for methicillin‐resistant S. aureus (MRSA) when they were exposed to 0.8 μm of TBD‐anchor at a low white light dose (25 mW cm?2) for 10 minutes. TBD‐anchor thus shows great promise as an effective antimicrobial agent to combat the menace of multidrug‐resistant bacteria. 相似文献
107.
S. Dzsaber M. Negyedi B. Bernth B. Gyüre T. Fehr C. Kramberger T. Pichler F. Simon 《Journal of Raman spectroscopy : JRS》2015,46(3):327-332
We present the development and performance of a Fourier transformation (FT)‐based Raman spectrometer working with visible laser (532 nm) excitation. It is generally thought that FT‐Raman spectrometers are not viable in the visible range where shot noise limits the detector performance and therein they are outperformed by grating based, dispersive ones. We show that contrary to this common belief, the recent advances of high‐performance interference filters makes the FT‐Raman design a valid alternative to dispersive Raman spectrometers for samples which do not luminesce. We critically compare the performance of our spectrometer to two dispersive ones: a home‐built single channel and a state‐of‐the‐art charge coupled device‐based instruments. We demonstrate a similar or even better sensitivity than the charge coupled device‐based dispersive spectrometer particularly when the laser power density is considered. The instrument possesses all the known advantages of the FT principle of spectral accuracy, high throughput, and economic design. We also discuss the general considerations, which helps the community reassess the utility of the different Raman spectrometer designs. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
108.
The x-ray diffraction technique has been used to measure surface residual stress in Ti-6Al-4V samples subjected to shot peening
(SP), laser shock peening (LSP) and low plasticity burnishing (LPB). The magnitude, spatial and directional dependence and
uniformity of the surface residual stresses have been investigated. The results show that residual stresses due to SP are
uniform and independent of direction. LSP has been observed to produce non-uniform residual stress varying from one region
to another, and also within a single laser shock. In the case of LPB, residual stresses have uniform spatial distribution
but have been observed to be direction-dependent. Various components of the residual stress tensor in the LPB sample have
been determined following the Dolle-Hauk method. The results of the residual stress due to three surface treatments are compared,
and possible reasons for spatial and directional dependence are discussed. 相似文献
109.
110.
光面爆破相邻炮孔存在起爆时差的炮孔间距计算 总被引:3,自引:1,他引:2
根据光面爆破炮孔爆炸载荷的时间衰减和相邻炮孔的非同时起爆,对光面爆破的炮孔间距计算进行研究,提出新的光面爆破参数设计方法,并得出炮孔爆炸载荷衰减速度、相邻炮孔起爆时差对炮孔间距的影响。分析认为,就实现较大的光面爆破炮孔间距而言,提高炮孔堵塞质量较提高雷管起爆时间精度更有意义。 相似文献