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951.
We construct boundary quantum group generators which, through linear intertwining relations, determine nondiagonal solutions of the boundary Yang–Baxter equation for vector representations of A
n-1
(1)
and A
2
(2)
. 相似文献
952.
影响消光比测试精度的主要因素分析 总被引:5,自引:0,他引:5
介绍了脉冲激光测距机消光比测试系统的功能和结构。对影响脉冲激光测距机消光比测试精度的主要因素逐一进行了分析。结果表明 ,用消光比测试方法考核验收脉冲激光测距机的最大测程和整机测距灵敏度 ,替代现行的在野外对特定目标的实际测距考核和验收 ,有效地克服了气象差异对测量精度的影响和地形条件对测试工作的限制 相似文献
953.
The tomographic map of the quantum state of a system with several degrees of freedom, which depends on one random variable, analogous to the rotated and scaled center-of-mass of the system, is constructed. The time-evolution equation of the tomogram for this map is given in the explicit form. The properties of the map such as the transition probabilities between different states and relation to the star-product formalism are elucidated. An example of a multimode oscillator is considered in detail. Identical particles are discussed within the framework of the proposed tomography scheme. 相似文献
954.
Near the interface between a normal metal and a superconductor, Cooper pairs penetrate into the normal side, giving rise to
the proximity effect. The two electrons of these pairs have entangled spin and orbital degrees of freedom. Nonlocal features
of quantum mechanics can be probed by separating these two electrons. This is achieved with a fork geometry with two normal
leads containing either spin- or energy-selective filters. A signature of entanglement can be detected by measuring the positive
noise cross-correlations in this fork. In the case of energy filters, Bell-inequality checks constitute a definite probe of
entanglement. We formulate Bell-type inequalities in terms of current-current cross-correlations associated with contacts
with varying magnetization orientations. We find maximal violation (as in photons) when a superconductor is the particle source. 相似文献
955.
Gregg A. Morgan Jr. 《Surface science》2007,601(17):3548-3555
We present a direct side-by-side comparison of the interaction of Li atoms and N2 molecules on the atomically stepped Ru(1 0 9) single crystal surface and on the atomically smooth Ru(0 0 1) single crystal surface using infrared reflection absorption spectroscopy (IRAS) and temperature programmed desorption (TPD). At low adsorbate coverages there is spectroscopic evidence for the formation of a Lix(N2)y complex on the Ru(1 0 9) surface, whereas no such complex is observed on the Ru(0 0 1) surface. This complex is due to local interactions between an adsorbed Li atom and N2 adsorbed on the atomic steps of Ru(1 0 9). The short range interaction near the atomic steps is characterized by the development of several highly red-shifted ν(N2) modes in the region of ∼2130 cm−1 in the IR spectra. Adsorbed N2 molecules on both Ru(1 0 9) and Ru(0 0 1) also are influenced by the long range electrostatic field produced by Li adsorbate atoms, causing a red shift in the uncomplexed N2 species, which monotonically increases as the Li coverage in increased. On the Ru(0 0 1) surface, small coverages of N2 influenced by the long range effect of Li are initially chemisorbed parallel to the surface resulting in the absence of infrared activity. In addition we have also found that Li does not cause N-N bond scission on Ru(0 0 1) below 250 K. 相似文献
956.
在GaAs(110)衬底上生长的半导体材料有诸多优良性能,使得在非极性GaAs(110)衬底上获得高质量各类异质结材料,成为近年来分子束外延生长关注的课题.考虑GaAs(110)表面是Ga和As共面,最佳生长温度窗口很小;反射式高能电子衍射的(1×1)再构图案对生长温度和V/Ⅲ束流比不敏感,难于通过观察再构图案的变化,准确地找到最佳生长条件.作者在制备GaAs(110)量子阱过程中,观察到反射式高能电子衍射强度振荡呈现出的单双周期变化.这意味着不同工艺条件下,在 GaAs(110)衬底上量子阱有单层和双层两种生长模式.透射电子显微镜和室温光致荧光光谱测量结果表明:在双层生长模式下量子阱样品光学性能较差,而在单层生长模式下量子阱光学性能较好,但是界面会变粗糙.利用这一特点,我们采用反射式高能电子衍射强度振荡技术,找到了一种在GaAs(110)衬底上生长高质量量子阱的可行方法.
关键词:
反射高能电子衍射
量子阱
分子束外延 相似文献
957.
958.
CT图像“条状”伪影校正方法研究 总被引:1,自引:0,他引:1
在CT重建中,当断层射线衰减系数的变化呈非连续性的跳跃变化,如一种材质密度远远大于另一种材质的密度时,CT图像中高密度物质周围就会产生条状伪影。利用重投影技术分别获取高密度物质和低密度物质的正弦图,低密度物质正弦图中的数据缺失区用线性插值技术进行平滑过渡。利用两幅正弦图分别进行CT重建,然后将两幅CT图像进行相加,得到校正后的图像。实验结果表明,该方法能有效抑制条状伪影,同时提高了图像对比度。 相似文献
959.
960.
Optical diffraction tomography (ODT) applied to measurement of optical microelements is limited by low dynamic range, i.e.,
only objects with small deviations of refractive-index distribution can be measured. Therefore in this paper the limitations
and errors of ODT are investigated throughout extensive numerical experiments. It is shown that these errors can be reduced
by introduction of additional numerical focusing in the tomographic reconstruction algorithm. Additionally, new tomographic
reconstruction algorithm using back propagation in reference medium for optical microelements measurement with known design
is proposed. This hybrid reconstruction algorithm allows significant extension of ODT applicability in measurement of elements
having large deviations of refractive-index distribution. 相似文献