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Co-doped TiO2 thin films are grown on TiN buffered silicon substrates by the pulsed laser deposition method and then hydrogenated. Transmission electron microscopy and high-angle annular dark-field scanning transmission electron microscopy measurements have shown that the TiN buffer layer can suffer a 400℃ deposition temperature and prevent the growth of silicon dioxide on silicon. After that, the room temperature ferromagnetism behaviors are observed in the hydrogenated samples, which are measured by the alternating gradient magnetometer. X- ray photoelectron spectroscopy and x-ray absorption fine structure measurements have revealed the existence of cobalt clusters. According to the material analysis, the magnetic behavior after hydrogenation is suggested to be induced by the enhancement of cobalt dusters. 相似文献
995.
By employing the balance condition between the lattice potential and the interatomic interaction, we study the ground state solutions of superfluid Fermi gases in Fourier-synthesized (FS) optical lattices. The average energy of the ground state, the atoms number, and the atom density distribution of the Fermi system are analytically derived along the Bose–Einstein condensation (BEC) side to the Bardeen–Cooper–Schrieffer (BCS) side. We analyze the properties of ground state solutions at both the BEC limit and unitarity in FS optical lattices. It is found that the relative phase α between the two lattice harmonics impacts greatly on the properties of the ground state of the superfluid Fermi gas. Especially in the BCS limit, when α=π/2, the average energy presents an exponential form with the increase of the potential depth of the lattice harmonics v2. Meanwhile, there exits a minimal value. Moreover, due to the Fermi pressure, the atom density distribution at unitarity is more outstretched than that in the BEC limit. The average energy at unitarity is apparently larger than that in the BEC limit. The properties of the ground state solution exhibit very different behaviors when the system transits from the BEC side to the BCS side. 相似文献
996.
Trap States in Al2O3 InAlN/GaN Metal-Oxide-Semiconductor Structures by Frequency-Dependent Conductance Analysis 下载免费PDF全文
ZHANG Peng ZHAO Sheng-Lei XUE Jun-Shuai ZHANG Kai MA Xiao-Hua ZHANG Jin-Cheng HAO Yue 《中国物理快报》2014,(3):137-139
We present a detailed analysis of the trap states in atomic layer deposition Al2O3/InAlN/GaN high electron mobility transistors grown by pulsed metal organic chemical vapor deposition. Trap densities, trap energies and time constants are determined by frequency-dependent conductance measurements. A high trap density of up to 1.6×1014 cm?2eV?1 is observed, which may be due to the lack of the cap layer causing the vulnerability to the subsequent high temperature annealing process. 相似文献
997.
We investigate the transport properties of a pair of Majorana bound states in a T-shaped junction, where two normal leads are coupled with an identical Majorana bound state. Both the scattering matrix and the recursive Green function method show that the peak value of the differential conductance (Gpeak) in units of e2/h and the shot noise Fano factor in the zero bias limit (F0), which are measured at the same lead and zero temperature, satisfy a linear relation as F0=1+Gpeak/2, independent of the magnitude or symmetry of the coupling strengths to the leads. Therefore, combined measurements of the differential conductance and shot noise in the T-shaped geometry can serve as a characteristic signature in probing Majorana bound states. 相似文献
998.
Electron Impact Excitation of Xenon from the Ground State and the Metastable State to the 5p57p Levels 下载免费PDF全文
Electron impact excitation cross sections from the ground state and the lowest metastable state 5p56s J=2 to the excited states of the 5p57p configuration of xenon are calculated systematically using the fully relativistic distorted wave method. Special attention is paid to the configuration interaction effects in the wave-function expansion of target states. The results are in good agreement with the recent experimental data by Jung et al. [Phys. Rev. A 80 (2009) 062708] over the measured energy range. These accurate theoretical results can be used in the modeling and diagnosis of plasmas containing xenon. 相似文献
999.
WANG Chong HE Yun-Long DING Ning ZHENG Xue-Feng ZHANG Peng MA Xiao-Hua ZHANG Jin-Cheng HAO Yue 《中国物理快报》2014,(3):177-180
In order to improve the breakdown voltage of AlGaN/GaN high electron mobility transistors (HEMTs), we report a feasible method of low density drain (LDD) HEMT. The fluoride-based plasma treatment using CF4 gas is performed on the drain-side of the gate edge. The channel two-dimensional electron gas (2DEG) concentrations are modulated by fluoride plasma treatment, and the peak electric field at the gate edge is effectively reduced, so the breakdown voltage is improved. The electric field distributions of the LDD-HEMTs are simulated using the Silvaco software, and the peak of the electric field on the gate edge is effectively reduced. Experimental results show that, compared with the conventional HEMT, LDD-HEMTs have a lower reverse leakage current of the gate, and the breakdown voltage is increased by 36%. The current collapse characteristics of the LDD-HEMTs are confirmed by dual-pulse measurement, and an obvious pulse current reduction is due to the surface states by implanting F ions between the gate and the drain. 相似文献
1000.
为了研究靶材料对快电子能量分布的影响,采用电子谱仪测量了飞秒激光与Cu和CH靶相互作用中在靶前和靶后产生的快电子能谱。结果显示,在靶前Cu和CH靶的快电子能谱相似,反应了快电子发射对靶材料的依赖性较弱;在靶后Cu和CH靶的快电子能谱具有明显的差异,说明电子的输运过程与靶材料密切相关。冷电子环流以及自生磁场是导致Cu靶快电子能谱"软化"的原因,而对于CH靶麦克斯韦分布的快电子能谱主要由碰撞机制决定。 相似文献