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141.
根据爱因斯坦方程和Marcus电荷传输模型, 使用密度泛函理论B3lyp/6-31g**理论水平计算6 个吐昔烯衍生物分子的结构和电荷传输性质. 结果显示: 6个吐昔烯的衍生物分子的空穴迁移速率为0.018–0.062 cm2·V-1·s-1, 电子迁移率为0.055–0.070 cm2·V-1·s-1, 其中3, 8, 13-辛烷氧基吐昔烯衍生物分子适合作为双极性传输材料. 三条烷氧基链的吐昔烯衍生物分子上引入三个甲氧基或羟基, 均使空穴和电子传输率降低. 引入给电子基团或共轭性基团可减小吐昔烯衍生物分子的能隙, 达到有机半导体的能隙要求.
关键词:
吐昔烯衍生物
空穴传输
电子传输
有机半导体 相似文献
142.
本文研究单分子磁体Na9[Cu3Na3(H2O)9 (α-AsW9O33)2]·26H2O中三角自旋 环在磁场作用下的热纠缠性质, 利用数值计算求出任意两个Cu2+离子量子比特之间的配对纠缠度, 分别记为C12, C23和C13. 研究结果表明, 磁场的方向和大小以及温度对配对纠缠度具有重要影响, 而且参数的变化对C12, C23和C13的影响也是各不相同. 给出外加三个不同方向的磁场时, 配对纠缠度C12, C23和C13各自对应的临界温度Tc随磁场强度的变化图, 由此可以得到单分子磁体三角自旋环中存在纠缠态的参数范围. 通过选择适当的磁场方向和大小以及温度等实验参数, 可以有效地调节和提高单分子磁体中的配对纠缠度.
关键词:
配对纠缠
单分子磁体
三角自旋环 相似文献
143.
基于密度泛函理论第一性原理系统研究了BN链掺杂石墨烯纳米带(GNRs)的电学及磁学特性, 对锯齿型石墨烯纳米带(ZGNRs)分非磁态(NM)、反铁磁态(AFM)及铁磁性(FM)三种情况分别进行考虑. 重点研究了单个BN链掺杂的位置效应. 计算发现: BN链掺杂扶手椅型石墨烯纳米带(AGNRs) 能使带隙增加, 不同位置的掺杂, 能使其成为带隙丰富的半导体. BN链掺杂非磁态ZGNR的不同位置, 其金属性均降低, 并能出现准金属的情况; BN链掺杂反铁磁态ZGNR, 能使其从半导体变为金属或半金属(half-metal), 这取决于掺杂的位置; BN链掺杂铁磁态ZGNR, 其金属性保持不变, 与掺杂位置无关. 这些结果表明: BN链掺杂能有效调控石墨烯纳米带的电子结构, 并形成丰富的电学及磁学特性, 这对于发展各种类型的石墨烯基纳米电子器件有重要意义.
关键词:
石墨烯纳米带
BN链掺杂
输运性质
自旋极化 相似文献
144.
145.
S. C. Tiwari 《Foundations of Physics Letters》2006,19(1):51-62
Advances in gauge theories and unified theories have not thrown light on the meaning of electron. The problem of the origin
of electronic charge is made precise, new insights gained from Weyl space are summarized, and the origin of charge in terms
of fractional spin is suggested. A new perspective on the abelian Chern-Simons theory is presented to explain charge. 相似文献
146.
Breathers in discrete nonlinear ferrimagnetic spin lattices are investigated for both easy-axis and easy-plane configurations.
The region in frequency space of the formation of breathers is determined and the anticontinuum limit discussed. The monochromatic
and the coloured breathers are found out numerically for different parameters and different conditions of excitations. 相似文献
147.
A. A. Shokri 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,50(3):475-481
Theoretical studies on spin-dependent transport in magnetic tunnel
heterostructures consisting of two diluted magnetic semiconductors
(DMS) separated by a nonmagnetic semiconductor (NMS) barrier, are
carried in the limit of coherent regime by including the effect of
angular dependence of the magnetizations in DMS. Based on
parabolic valence band effective mass approximation and
spontaneous magnetization of DMS electrodes, we obtain an
analytical expression of angular dependence of transmission for
DMS/NMS/DMS junctions. We also examine the dependence of spin
polarization and tunneling magnetoresistance (TMR) on barrier
thickness, temperature, applied voltage and the relative angle
between the magnetizations of two DMS layers in GaMnAs/GaAs/GaMnAs
heterostructures. We discuss the theoretical interpretation of
this variation. Our results show that TMR of more than 65% are
obtained at zero temperature, when one GaAs monolayer is used as a
tunnel barrier. It is also shown that the TMR decreases rapidly
with increasing barrier width and applied voltage; however at high
voltages and low thicknesses, the TMR first increases and then
decreases. Our calculations explain the main features of the
recent experimental observations and the application of the
predicted results may prove useful in designing nano spin-valve
devices. 相似文献
148.
R. R. Levitskii O. R. Baran B. M. Lisnii 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,50(3):439-443
The spin-1 Ising model with bilinear and quadrupolar short-range
interactions under magnetic field is investigated within the
two-particle cluster approximation. It is shown that for those
values of the quadrupolar interaction when at zero magnetic field
the system undergoes a temperature phase transition between
quadrupolar and paramagnetic phases, a triple point may exist in
the temperature vs. magnetic field phase diagrams, necessarily
along with a critical point. It is also shown that the critical
points in the temperature vs. magnetic field phase diagrams of the
investigated model can be of three types. 相似文献
149.
F.-J. Zhang Z. Xu Y.-G. Lv J.-C. Zhang S. L. Zhao J.-Z. Huang Y. Wang G.-C. Yuan D.-W. Zhao X.-R. Xu 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,52(2):245-248
The organic-inorganic combined structural device (ITO/PVK:Eu/ZnS/Al) is
fabricated based on layered optimization scheme. II–VI semiconductor
material ZnS is acted as an electron function (transporting and
acceleration) layer. The hot electrons which have been accelerated in the
ZnS layer directly impact excitation europium ions through resonant energy
transfer and then recombine with injected holes to form excitons in PVK or
EuTTA2(N-HPA)Phen. Europium (Eu) ions may also be excited by
intramolecular energy transfer from ligands. There are two kinds of
excitation mechanisms: impacted excitation and injected recombination for
the combined structural device. The electroluminescence (EL) intensity of
the combined structural device is strongly improved and reaches up to
381 cd/m2 at 20 V compared with the pure organic structural device. It
may be an effective method to improve the EL intensity of the lanthanide
complex by using electric characteristics of inorganic semiconductor
materials. 相似文献
150.
Bao Cheng-guang 《Frontiers of Physics in China》2006,1(1):92-96
A very effective tool, namely, the analytical expression of the fractional parentage coefficients (FPC), is introduced in
this paper to deal with the total spin states of N-body spinor bosonic systems, where N is supposed to be large and the spin of each boson is one. In particular, the analytical forms of the one-body and two-body
FPC for the total spin states with {N} and {N−1,1} permutation symmetries have been derived. These coefficients facilitate greatly the calculation of related matrix elements,
and they can be used even in the case of N→∞. They appear as a powerful tool for the establishment of an improved theory of spinor Bose-Einstein condensation, where
the eigenstates have the total spin S and its Z-component being both conserved. 相似文献