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排序方式: 共有178条查询结果,搜索用时 15 毫秒
11.
V. A. Tkachenko Z. D. Kvon O. A. Tkachenko D. G. Baksheev O. Estibals J. -C. Portal 《Physica E: Low-dimensional Systems and Nanostructures》2004,21(2-4):469
An AlGaAs/GaAs lateral quantum dot of triangular shape with a characteristic size L<100 nm containing less than ten electrons was studied. Single-electron oscillations of the conductance G of this dot were measured at G<e2/h. When going from Ge2/h to G≈0.5e2/h, a decrease was found not only in the amplitude but also in the period of the oscillations. A calculation of the 3D-electrostatics demonstrated that this effect is due to a change in the dot size produced by control voltages. 相似文献
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Jari M. Kinaret Mats Jonson Robert I. Shekhter Sebastian Eggert 《Physica E: Low-dimensional Systems and Nanostructures》1998,1(1-4)
We consider a mesoscopic ring connected to external reservoirs by tunnel junctions. The ring is capacitively coupled to an external gate electrode and may be pierced by a magnetic field. Due to strong electron–electron interactions within the ring the conductance shows Coulomb blockade oscillations as a function of the gate voltage, while Aharonov–Bohm interference effects lead to a dependence on the magnetic flux. The Hamiltonian of the ring is given by a Luttinger model that allows for an exact treatment of both interaction and interference effects. We conclude that the positions of conductance maxima as a function the external parameters can be used to determine the interaction parameter
, and the shapes of conductance peaks are strongly affected by electron correlations within the ring. 相似文献
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16.
Andreas Richter Ken-ichi Matsuda Tatsushi Akazaki Tadashi Saku Hiroyuki Tamura Yoshiro Hirayama Hideaki Takayanagi 《Physica E: Low-dimensional Systems and Nanostructures》2005,25(4):472-478
We present studies on the electric transport in a lateral GaAs/AlGaAs quantum dot defined by a patterned single connected metallic front-gate. This gate design allows to easily couple a large number of quantum dots and therefore holds high potential in the design of new materials with tailor-made band structures based on quantum dot superlattices of controlled shape. Clear Coulomb diamond structures and well pronounced tunneling peaks observed in experiment indicate that single-electron control has been achieved. However, the dependence on electron density in the heterostructure embedding the dot, which is controlled by an additional back-gate, reveals that transport characteristics are strongly influenced supposedly by potential fluctuations in the dot and lead regions. 相似文献
17.
Xin Lu Jing Wang Chang-Qin Wu 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,49(3):325-331
Phonon effects in tunnelling through a double quantum dot molecule
are investigated by use of a recently developed technique, which
is based on an exact mapping of a many-body electron-phonon
interaction problem onto a multichannel one-body problem. The
molecule is sandwiched between two ideal electrodes and the
electron at each dot of the molecule interacts independently with
Einstein phonons. Single-electron transmission rates through the
molecule are computed and the nonlinear spectrum obtained shows a
structure with many more satellite peaks due to the excitations of
phonons. The strength of resonant peaks is found to be strongly
dependent on the number of excited phonons. The effects of
electron-phonon interaction on the current and shot noise,
depending on the voltage bias applied at the two electrodes as
well as the potential energy of the molecule, are discussed. 相似文献
18.
单电子存储器 总被引:3,自引:0,他引:3
介绍了单电子存储器的发展情况和几种单电子存储器的基本特性,并将库仑阻塞效应作为存储器工作的理论基础进行了讨论。随着传统存储器集成度的不断提高,每个存储单元的电子数目不断减少,并逐渐接近其极限,使传统存储器的发展面临困难。采用单电子存储器有望解决这个困难,它们通常具有单个量子点或者是多隧穿结结构,存储一个比特的信息只需要精确控制增加或者减少一定数目的电子就可以实现。单电子器件的工作通常只需要很少的电子甚至一个电子就可以实现,具有高速和低功耗的特点,因此可以实现信息超高密度存储。与单电子逻辑电路相比,单电子存储器更容易解决随机背景电荷涨落的问题,因此从实际应用的角度来看,单电子存储器的应用前景更为光明。 相似文献
19.
传统的共振隧穿二极管的多峰值负微分电阻器件的峰值数目受到限制,由单电子器件和传统的金属氧化物半导体场效应晶体管(MOSFET)器件组成的多峰值负微分电阻器件在原理上具有无穷多个峰值,并且MOSFET使单电子晶体管(SET)的峰值和谷值电流大小受其源漏电压的影响减小.利用这种多峰值负微分电阻器件实现了多值存储器,该存储器原理上是无穷多值的.并且利用它的折叠的I-V特性,实现了一个4位的Flash A/D转换器,与传统的Flash A/D转换器相比,SET-MOSFET的A/D转换器大大地简化了电路.
关键词:
库仑阻塞
库仑振荡
负微分电阻
多值存储器 相似文献
20.
M. Hofheinz X. Jehl M. Sanquer G. Molas M. Vinet S. Deleonibus 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,54(3):299-307
We study anomalies in the Coulomb blockade spectrum of a quantum dot
formed in a silicon nanowire. These anomalies are attributed to electrostatic
interaction with charge traps in the device. A simple model reproduces these
anomalies accurately and we show how the capacitance matrices of the traps can
be obtained from the shape of the anomalies. From these capacitance matrices
we deduce that the traps are located near or inside the wire. Based on the
occurrence of the anomalies in wires with different doping levels we infer
that most of the traps are arsenic dopant states. In some cases the anomalies
are accompanied by a random telegraph signal which allows time resolved
monitoring of the occupation of the trap. The spin of the trap states is
determined via the Zeeman shift. 相似文献