全文获取类型
收费全文 | 294篇 |
免费 | 9篇 |
国内免费 | 1篇 |
专业分类
化学 | 103篇 |
力学 | 2篇 |
数学 | 64篇 |
物理学 | 135篇 |
出版年
2020年 | 5篇 |
2019年 | 4篇 |
2016年 | 9篇 |
2015年 | 8篇 |
2014年 | 6篇 |
2013年 | 8篇 |
2012年 | 8篇 |
2011年 | 16篇 |
2010年 | 7篇 |
2009年 | 9篇 |
2008年 | 8篇 |
2007年 | 8篇 |
2006年 | 9篇 |
2005年 | 8篇 |
2004年 | 10篇 |
2003年 | 10篇 |
2002年 | 8篇 |
2001年 | 4篇 |
2000年 | 10篇 |
1999年 | 5篇 |
1998年 | 5篇 |
1995年 | 4篇 |
1994年 | 11篇 |
1993年 | 4篇 |
1992年 | 6篇 |
1991年 | 3篇 |
1988年 | 3篇 |
1987年 | 6篇 |
1986年 | 4篇 |
1985年 | 4篇 |
1984年 | 3篇 |
1983年 | 4篇 |
1981年 | 10篇 |
1980年 | 5篇 |
1978年 | 2篇 |
1977年 | 6篇 |
1976年 | 3篇 |
1974年 | 3篇 |
1973年 | 5篇 |
1972年 | 4篇 |
1971年 | 4篇 |
1969年 | 2篇 |
1968年 | 7篇 |
1962年 | 2篇 |
1960年 | 2篇 |
1958年 | 2篇 |
1926年 | 2篇 |
1893年 | 2篇 |
1891年 | 2篇 |
1890年 | 2篇 |
排序方式: 共有304条查询结果,搜索用时 343 毫秒
251.
252.
The benefits and limitations of reaction cell and sector field inductively coupled plasma mass spectrometry in the detection and quantification of phosphopeptides
下载免费PDF全文
![点击此处可从《Rapid communications in mass spectrometry : RCM》网站下载免费的PDF全文](/ch/ext_images/free.gif)
253.
254.
Kang Cui Kunal S. Mali Dongqing Wu Xinliang Feng Klaus Müllen Michael Walter Steven De Feyter Stijn F. L. Mertens 《Angewandte Chemie (International ed. in English)》2020,59(33):14049-14053
Reported here is a molecular dipole that self‐assembles into highly ordered patterns at the liquid‐solid interface, and it can be switched at room temperature between a bright and a dark state at the single‐molecule level. Using a scanning tunneling microscope (STM) under suitable bias conditions, binary information can be written at a density of up to 41 Tb cm?2 (256 Tb/in2). The written information is stable during reading at room temperature, but it can also be erased at will, instantly, by proper choice of tunneling conditions. DFT calculations indicate that the contrast and switching mechanism originate from the stacking sequence of the molecular dipole, which is reoriented by the electric field between the tip and substrate. 相似文献
255.
Abdoul Karim Sakira Issa Touridomon Somé Eric Ziemons Bieke Dejaegher Dominique Mertens Philippe Hubert Jean‐Michel Kauffmann 《Electroanalysis》2015,27(2):309-316
A selective and sensitive electroanalytical method was developed for arsenic determination based on a nanogold (AuNP) modified solid carbon paste working electrode (SCPE) modified in two steps (i) physisorption and (ii) additional electrodeposition of nanogold particles in the presence of iodide. Copper(II) interference was solved by covering the gold layer by a self assembled mono layer (SAM) of glutathione. Using DPASV a linear response of the signal was obtained as a function of As(III) in the concentration range 0.05–20 µM (4–1498 ppb) with a limit of detection of 0.01 µM (0.9 ppb). Sample stirring and degassing were not needed. Application to the determination of arsenic(III) and (V) in underground water samples from Burkina Faso was successfully achieved. 相似文献
256.
M. Hauptmann F. Frederickx H. Struyf P. Mertens M. Heyns S. De Gendt C. Glorieux S. Brems 《Ultrasonics sonochemistry》2013,20(1):69-76
Megasonic cleaning as applied in leading edge semiconductor device manufacturing strongly relies on the phenomenon of acoustic cavitation. As the occurrence of acoustic cavitation is incorporating a multitude of interdependent effects, the amount of cavitation activity in the cleaning liquid strongly depends on the sonication conditions. It is shown that cavitation activity as measured by means of ultraharmonic cavitation noise can be significantly enhanced when pulsed sonication is applied to a gas supersaturated liquid under traveling wave conditions. It is demonstrated that this enhancement coincides with a dramatic increase in particle removal and is therefore of great interest for megasonic cleaning applications. It is demonstrated that the optimal pulse parameters are determined by the dissolution time of the active bubbles, whereas the amount of cavitation activity depends on the ratio between pulse-off and pulse-on time as well as the applied acoustic power. The optimal pulse-off time is independent of the corresponding pulse-on time but increases significantly with increasing gas concentration. We show that on the other hand, supersaturation is needed to enable acoustic cavitation at aforementioned conditions, but has to be kept below values, for which active bubbles cannot dissolve anymore and are therefore lost during subsequent pulses. For the applicable range of gas contents between 100% and 130% saturation, the optimal pulse-off time reaches values between 150 and 340 ms, respectively. Full particle removal of 78 nm-diameter silica particles at a power density of 0.67 W/cm2 is obtained for the optimal pulse-off times. The optimal pulse-off time values are derived from the dissolution time of bubbles with a radius of 3.3 μm and verified experimentally. The bubble radius used in the calculations corresponds to the linear resonance size in a 928 kHz sound field, which demonstrates that the recycling of active bubbles is the main enhancement mechanism. The optimal choice of the pulsing conditions however is constrained by the trade-off between the effective sonication time and the desire to have a sufficient amount of active bubbles at lower powers, which might be necessary if very delicate structures have to be cleaned. 相似文献
257.
E. Arévalo Yu. Gaididei F.G. Mertens 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,27(1):63-74
We investigate the dynamics of a lattice soliton on a monatomic chain in the presence of damping and external forces. We consider
Stokes and hydrodynamical damping. In the quasi-continuum limit the discrete system leads to a damped and forced Boussinesq
equation. By using a multiple-scale perturbation expansion up to second order in the framework of the quasi-continuum approach
we derive a general expression for the first-order velocity correction which improves previous results. We compare the soliton
position and shape predicted by the theory with simulations carried out on the level of the monatomic chain system as well
as on the level of the quasi-continuum limit system. For this purpose we restrict ourselves to specific examples, namely potentials
with cubic and quartic anharmonicities as well as the truncated Morse potential, without taking into account external forces.
For both types of damping we find a good agreement with the numerical simulations both for the soliton position and for the
tail which appears at the rear of the soliton. Moreover we clarify why the quasi-continuum approximation is better in the
hydrodynamical damping case than in the Stokes damping case.
Received 22 August 2001 and Received in final form 7 December 2001 相似文献
258.
P. T. Lang O. Gruber V. Mertens R. Neu F. Ryter W. Schneider A. C. C. Sips W. Suttrop S. H. Kim J. B. Lister Y. R. Martin S. Yu. Medvedev 《Czechoslovak Journal of Physics》2006,56(12):1329-1337
For the ITER project it is clear that steps have to be taken in order to avoid or mitigate type-I ELMs when operating in the
standard H-mode scenario. Otherwise, divertor power loads induced by intrinsic ELMs will result in an intolerably short divertor
life time. Amongst others, “magnetic triggering” based on a fast vertical movement of the plasma column has proven its ability
to achieve ELM frequency control and hence mitigation by locking the ELM frequency to the imposed motion. Here, we report
on an attempt to widen this approach by applying a cyclic radial plasma shift. Although motional cycle amplitudes sufficient
for ELM frequency locking were achieved even easier than in the vertical case, no ELM control was established for the radial
case. Analysis of this different behaviour can allow for better insight into underlying ELM release mechanisms and might potentially
be a useful tool for mapping out ELM stability boundaries.
Presented at the Workshop “Electric Fields, Structures and Relaxation in Edge Plasmas”, Roma, Italy, June 26–27, 2006. 相似文献
259.
260.
Photonic nanostructures for advanced light trapping in silicon solar cells: the impact of etching on the material electronic quality
下载免费PDF全文
![点击此处可从《固体物理学:研究快报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Christos Trompoukis Andre Stesmans Eddy Simoen Valérie Depauw Ounsi El Daif Kidong Lee Ivan Gordon Robert Mertens Jef Poortmans 《固体物理学:研究快报》2016,10(2):158-163
Dry plasma etching, commonly used by the Photonics community as the etching technique for the fabrication of photonic nanostructures, could be a source of device performance limitations when used in the frame of silicon photovoltaics. So far, the lack of silicon solar cells with state‐of‐the‐art efficiencies utilizing nanophotonic concepts shows how challenging their integration is, owing to the trade‐off between optical and electrical properties. In this study we show that dry plasma etching results in the degradation of the silicon material quality due to (i) a high density of dangling bonds and (ii) the presence of sub‐surface defects, resulting in high surface recombination velocities and low minority carrier lifetimes. On the contrary, wet chemical anisotropic etching used as an alternative, leads to the formation of inverted nanopyramids that result in low surface recombination velocity and low density of dangling bonds. The proposed inverted nanopyramids could enable high efficiency photonic assisted solar cells by offering the potential to achieve higher short‐circuit current without degrading the open circuit voltage. (© 2016 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim) 相似文献