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排序方式: 共有173条查询结果,搜索用时 46 毫秒
51.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. 相似文献
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Dabade Vivekanand Venkatraman Raghavendra James Richard D. 《Journal of Nonlinear Science》2019,29(2):415-460
Journal of Nonlinear Science - We study the micromagnetics of soft cubic ferromagnets with large magnetostriction, with the goal of understanding the microstructure and behavior of recently... 相似文献
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We have investigated the microstructures and magnetic properties of L10 ordered equi-atomic FePt thin films prepared by ion beam sputtering and subsequent annealing. It is observed from X-ray reflectivity
and X-ray diffraction measurements that the mixing at Fe/Pt interfaces starts to occur with annealing and leading to the FePt
alloy phase formation. The rapid increase in the coercivity values above 275°C, obtained from vibrating sample magnetometer
(VSM) measurements, confirms the formation of the ordered L10 FCT FePt phase. 相似文献
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Ramesh KP Suresh KS Raghavendra Rao C Ramakrishna J 《Magnetic resonance in chemistry : MRC》2008,46(6):525-533
The (35)Cl nuclear quadrupole resonance (NQR) frequencies (nu(Q)) in caesium and sodium chlorates were measured as a function of temperature, from 77 to 300 K at different pressures up to 5.1 kbar, and the data were analysed to estimate the volume dependence of the electric field gradient (EFG), torsional frequency and also the contributions to the NQR frequency from static and dynamic effects. The variation of spin-lattice relaxation time with pressure at different temperatures was studied in the case of sodium chlorate and at room temperature in case of caesium chlorate. The pressure dependence of the spin-lattice relaxation time (T(1)) suggests that the relaxation is mainly due to the torsional motions. 相似文献
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Hao Zhang Aleksei Bolshakov Raghavendra Meena Gustavo A. Garcia A. Iulian Dugulan Alexander Parastaev Guanna Li Emiel J. M. Hensen Nikolay Kosinov 《Angewandte Chemie (International ed. in English)》2023,62(32):e202306196
Non-oxidative coupling of methane is a promising route to obtain ethylene directly from natural gas. We synthesized siliceous [Fe]zeolites with MFI and CHA topologies and found that they display high selectivity (>90 % for MFI and >99 % for CHA) to ethylene and ethane among gas-phase products. Deactivated [Fe]zeolites can be regenerated by burning coke in air. In situ X-ray absorption spectroscopy demonstrates that the isolated Fe3+ centers in zeolite framework of fresh catalysts are reduced during the reaction to the active sites, including Fe2+ species and Fe (oxy)carbides dispersed in zeolite pores. Photoelectron photoion coincidence spectroscopy results show that methyl radicals are the reaction intermediates formed upon methane activation. Ethane is formed by methyl radical coupling, followed by its dehydrogenation to ethylene. Based on the observation of intermediates including allene, vinylacetylene, 1,3-butadiene, 2-butyne, and cyclopentadiene over [Fe]MFI, a reaction network is proposed leading to polyaromatic species. Such reaction intermediates are not observed over the small-pore [Fe]CHA, where ethylene and ethane are the only gas-phase products. 相似文献
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Raghavendra NM Thampi P Gurubasavarajaswamy PM Sriram D 《Chemical & pharmaceutical bulletin》2007,55(11):1615-1619
Several substituted-quinazolin-3(4H)-ones 8-11ad were synthesized by condensation of 2-chloro-N-(4-oxo-substituted-quinazolin-3(4H)-yl)-acetamides with various substituted imidazoles through one pot reaction. Elemental analysis, IR, (1)H-NMR and mass spectral data confirmed the structure of the newly synthesized compounds. Synthesized quinazolin-4-one derivatives were investigated for their antitubercular, antibacterial and antifungal activities. Some of the tested compounds showed good antitubercular activity. None of the synthesized compounds showed significant antibacterial and antifungal activity. 相似文献
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Ab initio, DFT, and AIM theoretical studies on H-, Cl-, and Li-bonded complexes have been carried out with typical lone pair (H2O), pi (C2H4) and sigma (H2) bonded pairs, and unpaired (CH3) electrons as acceptors and HF, ClF, and LiF as donors. Optimization and frequency calculations have been carried out at reasonably high levels (MP2, DFT(B3LYP), and QCISD) with large basis sets up to aug-cc-pVTZ. Not surprisingly, all HF complexes show red shift in stretching frequency and the shift is correlated to the binding energy. However, the FCl...CH3 complex shows a large blue shift (about 200 cm-1), which appears to be the largest blue shift predicted for any weakly bound complex yet. Analysis of the normal modes of the complex indicates that the shift is due to the mixing of modes between donor and acceptor and it is qualitatively different from the blue shifts reported thus far in hydrogen-bonded complexes. For Cl- and Li-bonded complexes, a correlation between frequency shift and binding energy is not found. However, AIM theoretical analysis shows the similarity in all these interactions. The electron density at the bond critical point shows a strong correlation with the binding energy for H-, Cl-, and Li-bonded complexes. This appears to be the first report on a one-electron chlorine bond. 相似文献