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41.
Dr. Ze-Jie Lv Wei Liu Miaomiao Zhu Zhengqi Chai Junnian Wei Prof. Wen-Xiong Zhang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(66):16498-16504
Although the reaction chemistry of transition metallacyclopropenes has been well-established in the last decades, the reactivity of rare-earth metallacyclopropenes remains elusive. Herein, we report the reaction of lutetacyclopropene 1 toward a series of unsaturated molecules. The reaction of 1 with one equiv. of PhCOMe, Ar1CHO (Ar1=2,6-Me2C6H3), W(CO)6, and PhCH=NPh provided oxalutetacyclopentenes, metallacyclic lutetoxycarbene, and azalutetacyclopentene via 1,2-insertion of C=O, C≡O, or C=N bonds into Lu−Csp2 bond, respectively. However, the reaction between 1 and Ar2N=C=NAr2 (Ar2=4-MeC6H4) gave an acyclic lutetium complex with a diamidinate ligand by the coupling of one molecule of 1 with two carbodiimides, irrespective of the amount of carbodiimide employed. More interestingly, when 1 was treated with two equiv. of Ar1CHO, the reductive coupling of two C=O bonds was discovered to give a lutetium pinacolate complex along with the release of tolan. Remarkably, the reactivity of 1 is significantly different from that of scandacyclopropenes; these metallacycles derived from 1 all represent the first cases in rare-earth organometallic chemistry. 相似文献
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Weishi Du Yaokang Lv Hongliang Lu Zaihua Chen Dominic S. Wright Cheng Zhang 《中国化学快报》2017,28(12):2285-2289
An efficient and cost-effective strategy to modificate the surface of active carbon (AC), form a 3D-conductive network, and therefore improve the electrochemical performance of AC based supercapacitor was developed. 相似文献
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High pressure can effectively control the phase transition of MoTe2 in experiment, but the mechanism is still unclear. In this work, we show by first-principles calculations that the phase transition is suppressed and phase becomes more stable under high pressure, which originates from the pressure-induced change of the interlayer band occupancies near the Fermi energy. Specifically, the interlayer states of phase tend to be fully occupied under high pressure, while they keep partially occupied for the phase. The increase of the band occupancies makes the phase more favorable in energy and prevents the structure changing from to phase. Moreover, we also analyze the superconductivity under high pressure based on BCS theory by calculating the density of states and phonon spectra. Our results may shed some light on understanding the relationship between the interlayer band occupancy and crystal stability of MoTe2 under high pressures. 相似文献
46.
Lei Wang Ruiquan Liu Cong Lv Junjun Ou Feng Liu Shangzhong Liu Min Wang Jiangchun Zhong 《Tetrahedron: Asymmetry》2013,24(4):173-177
Six optically active α-hydroxyl-β,γ-unsaturated acid esters 1a to 1f were synthesised, and they are significant moieties of the cerebrosides. The chiral intermediate alkynol 4 prepared by catalytic asymmetric addition had 99% ee, and which was converted into the target compounds 1a to 1f with high enantiomeric purity. 相似文献
47.
Under the influence of thiocyanate anions (SCN?) and cetyltrimethyl ammonium bromide (CTAB), NiS flower-like architectures were successfully synthesized by a one-step hydrothermal method. The synthesized flower-like architectures, with a multilayered and highly ordered texture, have diameters of several micrometers. X-ray powder diffraction (XRD) shows that the NiS flower-like architectures are rhombohedral crystalline. On the basis of condition-dependent experiments, the diffusion-limited aggregation (DLA) model and cage effect were used to explain the growth process of rhombohedral crystalline NiS flower-like architectures. Magnetic measurements showed that the coercivity (Hc) of the as-obtained NiS flower-like architectures was 102.14 Oe. 相似文献
48.
Pingli Lv Rongxiu Zhu Tongxiang Lu Steven E. Wheeler Dongju Zhang Ruoxi Wang Chengbu Liu 《Tetrahedron: Asymmetry》2013,24(24):1598-1604
Computational studies to determine the origin of enantioselectivity in the (1R,2R)-1,2-diphenylethane-1,2-diamine (DEPN)–Brønsted acid catalyzed epoxidation of 2-cyclohexen-1-one have been performed using density functional theory. Transition states for conjugate addition and ring closure steps of the epoxidations catalyzed by three different catalyst systems were characterized. Our calculations show that the Csp2H?O H-bond interaction between the benzene ring of the catalyst and H2O is mainly responsible for the chiral discrimination observed. The Brønsted acid counterion plays a very important role in ensuring high enantioselectivity by improving the rigidity of the transition state structures to allow the efficient formation of the Csp2H?O H-bond. Moreover, we explain why these two diamine catalysts (1S,2S)-DACH and (1R,2R)-DPEN display consistent enantioselectivities in the catalytic epoxidation of 2-cyclohexen-1-one when combining with three different cocatalysts; achiral TFA, and chiral (R)- and (S)-TRIP. 相似文献
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Dr. Yukun Zhu Chunxiao Lv Zhuocheng Yin Prof. Jun Ren Prof. Xianfeng Yang Prof. Chung-Li Dong Prof. Hongwei Liu Dr. Rongsheng Cai Yu-Cheng Huang Prof. Wolfgang Theis Prof. Shaohua Shen Prof. Dongjiang Yang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(2):878-883
Red phosphorus is a promising photocatalyst with wide visible-light absorption up to 700 nm, but the fast charge recombination limits its photocatalytic hydrogen evolution reaction (HER) activity. Now, [001]-oriented Hittorf's phosphorus (HP) nanorods were successfully grown on polymeric carbon nitride (PCN) by a chemical vapor deposition strategy. Compared with the bare PCN and HP, the optimized PCN@HP hybrid exhibited a significantly enhanced photocatalytic activity, with HER rates reaching 33.2 and 17.5 μmol h−1 from pure water under simulated solar light and visible light irradiation, respectively. It was theoretically and experimentally indicated that the strong electronic coupling between PCN and [001]-oriented HP nanorods gave rise to the enhanced visible light absorption and the greatly accelerated photoinduced electron–hole separation and transfer, which benefited the photocatalytic HER performance. 相似文献