全文获取类型
收费全文 | 136篇 |
免费 | 0篇 |
专业分类
化学 | 49篇 |
晶体学 | 1篇 |
力学 | 15篇 |
数学 | 1篇 |
物理学 | 70篇 |
出版年
2022年 | 1篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 3篇 |
2017年 | 2篇 |
2016年 | 1篇 |
2015年 | 2篇 |
2014年 | 1篇 |
2013年 | 6篇 |
2012年 | 2篇 |
2011年 | 2篇 |
2010年 | 7篇 |
2009年 | 9篇 |
2008年 | 8篇 |
2007年 | 3篇 |
2006年 | 8篇 |
2005年 | 4篇 |
2004年 | 3篇 |
2003年 | 3篇 |
2002年 | 9篇 |
2001年 | 4篇 |
2000年 | 8篇 |
1999年 | 5篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 4篇 |
1995年 | 6篇 |
1994年 | 4篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 3篇 |
1987年 | 1篇 |
1986年 | 4篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1979年 | 2篇 |
1971年 | 3篇 |
1969年 | 1篇 |
排序方式: 共有136条查询结果,搜索用时 375 毫秒
41.
Habara H Adumi K Yabuuchi T Nakamura T Chen ZL Kashihara M Kodama R Kondo K Kumar GR Lei LA Matsuoka T Mima K Tanaka KA 《Physical review letters》2006,97(9):095004
We report an observation of surface acceleration of fast electrons in intense laser-plasma interactions. When a preformed plasma is presented in front of a solid target with a higher laser intensity, the emission direction of fast electrons is changed to the target surface direction from the laser and specular directions. This feature could be caused by the formation of a strong static magnetic field along the target surface which traps and holds fast electrons on the surface. In our experiment, the increase in the laser intensity due to relativistic self-focusing in plasma plays an important role for the formation. The strength of the magnetic field is calculated from the bent angle of the electrons, resulting in tens of percent of laser magnetic field, which agrees well with a two-dimensional particle-in-cell calculation. The strong surface current explains the high conversion efficiency on the cone-guided fast ignitor experiments. 相似文献
42.
Keiji Nagai Qincui Gu Yuzuri Yasuda Takayoshi Norimatsu Shinsuke Fujioka Hiroaki Nishimura Noriaki Miyanaga Yasukazu Izawa Kunioki Mima 《Journal of polymer science. Part A, Polymer chemistry》2009,47(18):4566-4576
A series of tin‐doped hydroxypropyl cellulose (HPC) lyotropic liquid crystal (LC) was synthesized using a simple process and their properties were characterized using selective reflection, wide‐angle X‐ray diffraction (WAXD), and the band texture observed under polarized optical microscope. The present preparation is applicable for mass production using large substrate with low cost HPC. A cholesteric lyotropic LC phase was observed for the hybrid solution with higher than 40 wt % HPC. After sol–gel condensation, the HPC‐Sn hybrid LC films were calcined at 400 °C and the as‐prepared product was determined to obtain tin dioxide (SnO2) which was characterized using WAXD. The iridescent color and ~2 nm structure seen after the condensation disappeared in the as‐prepared SnO2. Scanning electronic microscope images of the SnO2 showed that the HPC content in the HPC‐Sn hybrid played an important role in controlling the SnO2 morphology. A spectrum of relatively monochromatic extreme ultraviolet (13.5 nm) emission was measured in the as‐prepared SnO2 in comparison with bulk tin and inverse opal SnO2. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 4566–4576, 2009 相似文献
43.
A.?SanthiEmail author U.L.?Kala R.J.?Nedumpara A.?Kurian M.R.P.?Kurup P.?Radhakrishnan V.P.N.?Nampoori 《Applied physics. B, Lasers and optics》2004,79(5):629-633
The fluorescence spectrum of the schiff base obtained from salicylaldehyde and 2-aminophenol is studied using an argon-ion laser as the excitation source and its fluorescence quantum yield (Qf) is determined using a thermal lens method. This is a nondestructive technique that gives the absolute value of Qf without the need for a fluorescence standard. The quantum-yield values are calculated for various concentrations of the solution in chloroform and also for various excitation wavelengths. The value of Qf is relatively high, and is concentration dependent. The maximum value of Qf obtained is nearly 0.78. The high value of the fluorescence quantum yield will render the schiff base useful as a fluorescent marker for biological applications. Photostability and gain studies will assess its suitability as a laser dye. PACS 42.55.Mv; 42.62.Cf; 42.62.Fi; 42.70.Hj 相似文献
44.
Kodama R Tanaka KA Sentoku Y Matsushita T Takahashi K Fujita H Kitagawa Y Kato Y Yamanaka T Mima K 《Physical review letters》2000,84(4):674-677
Long-scale jetlike x-ray emission was observed in a 100-TW laser-plasma interaction. The jet was well collimated with a divergence of 30-40 mrad and continued from the target surface into underdense regions for a distance over 4 mm in the specular direction of the laser light. A two-dimensional particle-in-cell simulation shows an electron acceleration with the specularly reflected laser light and collimation of the electron stream by a self-generated magnetic field, resulting in the electron jet to the direction of the specularly reflected light. 相似文献
45.
Y. Sentoku V.Y. Bychenkov K. Flippo A. Maksimchuk K. Mima G. Mourou Z.M. Sheng D. Umstadter 《Applied physics. B, Lasers and optics》2002,74(3):207-215
Multi-MeV ion production from the interaction of a short laser pulse with a high-density plasma, accompanied by an underdense
preplasma, has been studied with a particle-in-cell simulation and good agreement is found with experiment. The mechanism
primarily responsible for the acceleration of ions is identified. Comparison with experiments sheds light on the ion-energy
dependence on laser intensity, preplasma scale length, and relative ion energies for a multi-species plasma. Two regimes of
maximum ion-energy dependence on laser intensity, I, have been identified: subrelativistic, ∝I; and relativistic, ∝. Simulations show that the energy of the accelerated ions versus the preplasma scale length increases linearly and then saturates.
In contrast, the ion energy decreases with the thickness of the solid-density plasma.
Received: 13 December 2001 / Published online: 7 February 2002 相似文献
46.
Esirkepov TZh Bulanov SV Nishihara K Tajima T Pegoraro F Khoroshkov VS Mima K Daido H Kato Y Kitagawa Y Nagai K Sakabe S 《Physical review letters》2002,89(17):175003
In order to achieve a high-quality, i.e., monoenergetic, intense ion beam, we propose the use of a double-layer target. The first layer, at the target front, consists of high-Z atoms, while the second (rear) layer is a thin coating of low-Z atoms. The generation of high-quality proton beams from the double-layer target, irradiated by an ultraintense laser pulse, is demonstrated with three-dimensional particle-in-cell simulations. 相似文献
47.
Structure formation and tearing of an MeV cylindrical electron beam in a laser-produced plasma 总被引:1,自引:0,他引:1
The stability of a cylindrical, solid hot electron beam propagating in a high density plasma has been studied using a two-dimensional, hybrid Darwin code. The initially solid beam evolves into a hollow, annular beam due to the Weibel instability and generates strong magnetic fields on both sides of the annular ring. The annular structure subsequently breaks up into several beamlets via a mechanism similar to a tearing instability. It is found that the magnetic fields parallel to the direction of beam propagation also grow due to the tearing process. 相似文献
48.
49.
The tension-leg platform (TLP) is a hybrid type of offshore platform, fixed for the vertical degrees of freedom and compliant
for the horizontal degrees of freedom. The platform structure is connected to the sea-bed foundation by vertical moorings
(tension legs) which are kept in tension under all conditions by the excess buoyancy over weight of the platform. Hydrodynamic
analysis is an important stage of the design of these structures; model tests are usually done for this purpose. This paper
gives the details of an experimental study to analyze the behavior of a 1:50 TLP model subjected to the action of regular
and irregular waves. Platform motions in surge, sway and heave directions were measured using accelerometers. Tether tensions
were measured using specially developed load cells. Details of instrumentation, testing and analysis to obtain response amplitude
operators (RAOs) are explained. The connection of tether to the column, arrangement for adjusting pretension from top, connection
of load cell to the tether and provision for changing the angle of incidence of waves are some special features of this experimental
study. The work reported will serve as a useful practical guide for similar types of experimental study. In addition, the
conclusions on the comparison of RAOs of the model for regular and irregular waves will be useful in planning hydrodynamic
model tests. 相似文献
50.
Mima Č. Romanović Božidar Čobeljić Andrej Pevec Iztok Turel Katarina Anđelković Marina Milenković 《Journal of Coordination Chemistry》2017,70(14):2425-2435
Two Zn(II) complexes with the condensation product of 2-quinolinecarboxaldehyde and trimethylammonium acetohydrazide chloride (Girard’s T reagent) (HLCl) and monodentate pseudohalides (azide and cyanate) have been synthesized and characterized by elemental analysis, IR and NMR spectroscopy, and single-crystal X-ray diffraction. In both complexes, the coordination surroundings of the Zn(II) ions consist of a deprotonated hydrazone ligand coordinated through an NNO set of donor atoms and two monodentate pseudohalides (N3– or NCO–) at the remaining coordination sites. The Zn(II) complexes showed low to moderate activity against laboratory control strains of pathogenic bacteria and fungi. 相似文献