全文获取类型
收费全文 | 84篇 |
免费 | 3篇 |
专业分类
化学 | 29篇 |
晶体学 | 1篇 |
力学 | 2篇 |
数学 | 3篇 |
物理学 | 52篇 |
出版年
2017年 | 1篇 |
2015年 | 4篇 |
2014年 | 1篇 |
2013年 | 9篇 |
2012年 | 3篇 |
2011年 | 3篇 |
2010年 | 2篇 |
2009年 | 1篇 |
2008年 | 3篇 |
2007年 | 2篇 |
2006年 | 2篇 |
2005年 | 1篇 |
2004年 | 1篇 |
2003年 | 4篇 |
2002年 | 3篇 |
2001年 | 1篇 |
2000年 | 7篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1996年 | 5篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1982年 | 4篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1973年 | 1篇 |
1968年 | 1篇 |
1964年 | 1篇 |
1893年 | 1篇 |
排序方式: 共有87条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Fiksel G Hudson B Den Hartog DJ Magee RM O'Connell R Prager SC Beklemishev AD Davydenko VI Ivanov AA Tsidulko YA 《Physical review letters》2005,95(12):125001
Fast ions are observed to be very well confined in the Madison Symmetric Torus reversed field pinch despite the presence of stochastic magnetic field. The fast-ion energy loss is consistent with the classical slowing down rate, and their confinement time is longer than expected by stochastic estimates. Fast-ion confinement is measured from the decay of d-d neutrons following a short pulse of a 20 keV atomic deuterium beam. Ion confinement agrees with computation of particle trajectories in the stochastic magnetic field, and is understood through consideration of ion guiding center islands. 相似文献
5.
Ivanov AA Anikeev AV Bagryansky PA Deichuli PP Korepanov SA Lizunov AA Maximov VV Murakhtin SV Savkin VY Den Hartog DJ Fiksel G Noack K 《Physical review letters》2003,90(10):105002
In the axially symmetric magnetic mirror device gas dynamic trap (GDT), on-axis transverse beta (ratio of the transverse plasma pressure to magnetic field pressure) exceeding 0.4 in the fast ion turning points has been first achieved. The plasma has been heated by injection of neutral beams, which at the same time produced anisotropic fast ions. Neither enhanced losses of the plasma nor anomalies in the fast ion scattering and slowing down were observed. This observation confirms predicted magnetohydrodynamic stability of plasma in the axially symmetric mirror devices with average min-B, like the GDT is. The measured beta value is rather close to that expected in different versions of the GDT based 14 MeV neutron source for fusion materials testing. 相似文献
6.
Magee RM Den Hartog DJ Kumar ST Almagri AF Chapman BE Fiksel G Mirnov VV Mezonlin ED Titus JB 《Physical review letters》2011,107(6):065005
Complementary measurements of ion energy distributions in a magnetically confined high-temperature plasma show that magnetic reconnection results in both anisotropic ion heating and the generation of suprathermal ions. The anisotropy, observed in the C(+6) impurity ions, is such that the temperature perpendicular to the magnetic field is larger than the temperature parallel to the magnetic field. The suprathermal tail appears in the majority ion distribution and is well described by a power law to energies 10 times the thermal energy. These observations may offer insight into the energization process. 相似文献
7.
Reusch JA Anderson JK Den Hartog DJ Ebrahimi F Schnack DD Stephens HD Forest CB 《Physical review letters》2011,107(15):155002
New high time resolution measurements of the electron thermal diffusion χ(e) throughout the sawtooth cycle of the Madison Symmetric Torus reversed-field pinch have been made by utilizing the enhanced capabilities of the upgraded multipoint, multipulse Thomson scattering system. These measurements are compared to the χ(e) due to magnetic diffusion predicted by using information from a new high spectral resolution zero-β nonlinear resistive magnetohydrodynamic simulation performed, for the first time, at the Lundquist number of high current Madison Symmetric Torus plasmas (S≈4×10(6)). Agreement between the measured and predicted values is found only if the reduction in thermal diffusion due to trapped particles is taken into account. 相似文献
8.
Thorsten vomStein Tim denHartog Julien Buendia Spas Stoychev Jakob Mottweiler Carsten Bolm Jürgen Klankermayer Walter Leitner 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(20):5957-5961
Ruthenium–triphos complexes exhibited unprecedented catalytic activity and selectivity in the redox‐neutral C C bond cleavage of the β‐O‐4 lignin linkage of 1,3‐dilignol model compounds. A mechanistic pathway involving a dehydrogenation‐initiated retro‐aldol reaction for the C C bond cleavage was proposed in line with experimental data and DFT calculations. 相似文献
9.
H. J. Vanes D. I. Vainshtein R. J. De Meijer H. W. Den Hartog J. F. Donoghue A. Rozendaal 《辐射效应与固体损伤》2013,168(6-12):1063-1070
Mineral zircon contains trace amounts (typically 10-1000 v ppm) of the f -emitters uranium and thorium, which irradiate this mineral internally. This outstanding feature of zircon turns out to be extremely useful when this mineral is applied as a thermoluminescence (TL) dating medium, because the build-up of the age-dependent luminescence is dominated by the presence of well-defined internal radioactive sources and the contributions to the dose from external radiation sources are two orders of magnitude smaller. The results presented in this paper have led us to the conclusion that for zircon dating it is necessary to carefully select the best and homogeneous zircon grains of the highest optical quality. For successful dating experiments on very young and historically well-defined coastal dune sands, selection of the most stable luminescence component by means of narrow band interference filters is needed. Our results suggest that ultimately optical zircon dating will allow us to determine the age of extremely young samples ( e.g. 12 months!). 相似文献
10.