全文获取类型
收费全文 | 154篇 |
免费 | 40篇 |
国内免费 | 11篇 |
专业分类
化学 | 52篇 |
力学 | 41篇 |
综合类 | 6篇 |
数学 | 20篇 |
物理学 | 86篇 |
出版年
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 7篇 |
2020年 | 10篇 |
2019年 | 4篇 |
2018年 | 2篇 |
2017年 | 6篇 |
2016年 | 4篇 |
2015年 | 10篇 |
2014年 | 8篇 |
2013年 | 13篇 |
2012年 | 12篇 |
2011年 | 12篇 |
2010年 | 14篇 |
2009年 | 9篇 |
2008年 | 8篇 |
2007年 | 13篇 |
2006年 | 9篇 |
2005年 | 1篇 |
2004年 | 9篇 |
2003年 | 8篇 |
2002年 | 4篇 |
2001年 | 6篇 |
2000年 | 2篇 |
1999年 | 5篇 |
1998年 | 6篇 |
1997年 | 3篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1981年 | 3篇 |
排序方式: 共有205条查询结果,搜索用时 812 毫秒
91.
We report significant improvements in both signal sensitivity and imaging speed of Fourier transform spectral interferometry coherent anti‐Stokes Raman scattering (FTSI‐CARS) microscopy. With a help of an apodization function in the signal retrieval process, background due to the spectral change of nonresonant signals is eliminated. We experimentally verify that the sensitivity of the improved method is nearly shot‐noise‐limited. The current maximum detection sensitivity is ∼10 mM of aqueous sulfate ions, which correspond to ∼106 oscillators in the microscopy focal volume. Operating the charge‐coupled device (CCD) in the crop mode increases the image acquisition speed by more than ten times. A vibrational hyperspectral image of a polymer sample with 100 × 100 pixel can be obtained within 3 s. With the improved sensitivity and speed, we also perform three‐dimensional volume imaging. Superior chemical selectivity is demonstrated with a mixture of two different oil droplets, which have identical vibrational peak positions but different relative peak ratios. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
92.
Asif Ali 《Tetrahedron》2010,66(24):4357-4279
We report a new and convergent strategy for the total synthesis of fully lipidated glycosylphosphatidylinositol (GPI) anchor, the major pro-inflammatory factor of malarial parasite (Plasmodium falciparum). The key features of our approach include, the access to the key glucosamine-inositol intermediate by a novel route without a priori resolution of myo-inositol, convergent assembly of the tetramannose glycan domain, flexibility for the placement of the three fatty acids in the desired order in the final steps, and the opportunity to construct GPI analogues/mimics to probe the biosynthesis, immunology and cell biology of the GPI anchor pathway in the malaria parasite. 相似文献
93.
The shot noise of a parallel double quantum dot (DQD) system under the perturbation of microwave fields is investigated in the weak Kondo regime. Peak-valley structures exhibit in the differential conductance and shot noise, and side resonant peaks emerge around the Kondo peak due to the absorption and emission of photons. The shot noise is sensitively dependent on the adjusting approach through changing the gate voltages. Large resonant Fano factor accompanying photon-induced side peaks appear by simultaneously varying the two gate voltages. The photon suppression and enhancement of shot noise have been evaluated corresponding to the coherent and incoherent current correlation. The destructive interference causes the suppression of shot noise by changing the Aharonov–Bohm phase. 相似文献
94.
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
95.
96.
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
97.
98.
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
99.
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
100.