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91.
H9^+团簇的体心立方结构与能量的理论计算 总被引:1,自引:1,他引:0
此文利用单电子在中心氢原子核与周围每个氢原子核之间形成单电子键的共振模型来划分通道,将改进的排列通道量子力学方法推广应用于H9+的体心立方结构与能量的理论计算。结果发现,当中心与周围顶角问距R0=1.90a0时,总能量有一极小值-4.308h.a.u,表明H9=的体心立方结构是稳定存在的。此外,H9团簇电离时体积要发生膨胀,大约膨胀到原来的1.5倍。 相似文献
92.
93.
A saturation-spectroscopy experiment is performed in a three-level system in Xe I, and shows that a narrow dip occurs in the
power-broadened Lorentzian response. It is due to the Zeeman splitting of common level by the earth magnetic field. Other
splittings, typically larger than 0.2 the natural width, can be observed using this saturation effect. Interpretation is made
on the basis of simple realistic assumptions.
Associé à l'Université Paris-Sud 相似文献
94.
H^—5的正四面体中心和正方形中心构型能量的理论计算 总被引:2,自引:1,他引:1
文中用MACQM(modifiedarangementchannelquantummechanics)方法计算了负离子团簇H-5的正四面体中心和正方形中心构型的能量随中心原子核到顶角原子核间距离R变化的曲线。计算得知,两种构型均在R=1.55a0时有能量极小值E正四面体中心=-2.7899a.u.,E正方形中心=-2.7539a.u.。说明H-5的这两种结构都可能存在,但正四面体中心结构较为稳定。 相似文献
95.
96.
In this paper, based on the topological basis states, we investigate the Hamiltonian family {H2,H3,H4} of a closed four-qubit Haldane–Shastry spin chain. Not only the two-qubit interaction form, but also the three-qubit interaction form and the four-qubit interaction form are presented in terms of spin operators. Meanwhile, we explore some particular properties of the topological basis states in these systems. With Yangian algebra, the symmetry of the systems and the transitions between the eigenstates have been investigated. We find a really useful effect of Y(sl(2)) operators {J±,J3}, which is that they can describe the transitions between the spin single state and the spin triple states. Furthermore, we construct a new Hamiltonian, whose energy degeneracies can be changed by adjusting the strengths of the two-qubit interactions, three-qubit interactions, four-qubit interactions, and the external magnetic field. 相似文献
97.
Weixing Li Luca Evangelisti Qian Gou Walther Caminati Rolf Meyer 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(3):869-875
The rotational spectra of three C‐deuterated isotopologues of the dimer of formic acid have been measured, thanks to the small dipole moment induced by asymmetric H→D substitution(s). For the DCOOH–HCOOH species, the concerted double proton transfer of the two hydroxy hydrogen atoms takes place between two equivalent minima and generates a tunneling splitting of 331.2(6) MHz. This splitting can be reproduced by a 3D model with a barrier of 2559 cm?1 (30.6 kJ mol?1) as obtained from theoretical calculations. 相似文献
98.
99.
Qi-Hui Zhang Ling Tan Qian Gou Chong-Zhi Wang Chun-Su Yuan 《Natural product research》2019,33(9):1243-1250
Two flavone di-C-glycosides, a pair of isomers, were isolated from Scutellaria baicalensis. The structures of compounds 1 and 2 were elucidated by means of physical data, including 1D and 2D NMR and HR-ESI-MS. Supporting theoretical calculations of the compound conformational landscape has also been conducted for geometry optimization. This is the first report of the natural occurrence of β-furanoarabinoside. In addition, the effects of compounds 1 and 2 on NO, pro-inflammatory cytokines, PGE2 and COX-2 levels were measured in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells. The pair of isomers exhibited significant inhibitory effects on inflammation. 相似文献
100.
Green's functions can be retrieved between receivers from the correlation of ambient seismic noise or with an appropriate set of randomly distributed sources. This principle is demonstrated in small-scale geophysics using noise sources generated by human steps during a 10-min walk in the alignment of a 14-m-long accelerometer line array. The time-domain correlation of the records yields two surface wave modes extracted from the Green's function between each pair of accelerometers. A frequency-wave-number Fourier analysis yields each mode contribution and their dispersion curve. These dispersion curves are then inverted to provide the one-dimensional shear velocity of the near surface. 相似文献