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121.
E. V. Kondrashov L. P. Oznobikhina T. N. Aksamentova N. N. Chipanina A. R. Romanov A. Yu. Rulev 《Journal of Physical Organic Chemistry》2016,29(6):288-298
Electron donating ability of the oxygen, nitrogen, and carbon atoms of captodative aminoenones R'CH = C(NR2)EWG, EWG = CHO, C(O)Me, C(O)CF3, C(O)Ph was investigated using ab initio and Density Functional Theory (DFT) calculations, Natural Bond Analysis (NBO) analysis, and Fourier Transform InfraRed (FTIR) spectroscopy. The influence of both electron withdrawing group (EWG) and double bond substituents on the proton affinity of the basic centers, orbital interaction, as well as resonance stabilization energies between heteroatoms and double bonds are discussed. The results obtained are critically compared with the push–pull aminoenones. The comparison of experimental values ΔνOH and theoretical values of H‐bonding energy was used to determine the H‐complex type of aminoenone with phenol and the H‐bond strength. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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E. K. Kondrashov N. I. Nefedov N. P. Vereninova P. P. Kushch G. A. Kichigina D. P. Kiryukhin V. M. Buznik 《Polymer Science Series D》2016,9(2):212-218
In this work, modification of coatings based on FP-5182 lacquer that is prepared from the copolymer of trifluorochloroethylene and vinylidenefluoride (F-32L) has been performed in order to improve their hydrophobicity. Several approaches to modification have been suggested, among which is the use of telomeric solutions of tetrafluoroethylene that were synthesized in various solvents, variation of the roughness of the coating surface by the aerosil powder, and a combination of these two approaches. The wetting properties of coatings have been studied, and improvement of the hydrophobic characteristics during their modification has been demonstrated. 相似文献
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用相对论有效原子实势 (RECP)和密度泛函 (B3LYP SDD)方法研究了UH ,UH2 基态和低激发态的结构和势能函数 ,导出了分子的光谱数据 .结果表明 ,UH和UH2 的基电子状态分别为X4 Π和X3A2 ,离解能分别为 2 .886eV和5 .2 4 9eV ,UH2 具有C2v对称性 ,得到了UH和UH2 的几个不同的低激发态的结构与光谱数据 .应用多体项展式理论以及数字拟合方法 ,计算得到了UH分子和基态UH2 三原子分子的分析势能函数 ,该函数正确反映了UH和UH2分子的结构特征 ,可用于研究UHH的微观反应动力学 . 相似文献
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制备了用于分离C60和C70的2,4,6-三硝基苯酚改性锆镁复合氧化物高效液相色谱固定相,并用元素分析仪、红外光谱仪和比表面积分析仪等对其进行了表征。考察了流动相中甲苯含量和柱温对C60和C70分离的影响。同时考察了以甲苯为流动相,在348 K的柱温下,该固定相分离富勒烯混合物(含3%高富勒烯)的情况。结果表明,2,4,6-三硝基苯酚改性锆镁复合氧化物固定相对富勒烯有较强的保留,并表现出较强的温度关系,提高柱温能提高固定相对富勒烯的分离能力,并具有用于富勒烯制备分离的潜力。 相似文献
125.
制备了用于分离C60和C70的芘基丁酸改性锆-镁复合氧化物高效液相色谱固定相,并对其进行了表征;考察了流动相中甲苯含量、柱温和进样量对C60和C70分离的影响.结果表明,芘基丁酸改性锆-镁复合氧化物固定相对富勒烯有较强的保留,并对富勒烯表现出较强的分离能力,具有制备分离富勒烯的潜力. 相似文献
126.
Andrei V. Afonin Igor A. Ushakov Alexander V. Vashchenko Evgeniy V. Kondrashov Alexander Yu. Rulev 《Magnetic resonance in chemistry : MRC》2010,48(9):661-670
In the series of diaminoenones, large high‐frequency shifts of the 1H NMR of the N? H group in the cis‐position relative to the carbonyl group suggests strong N? H···O intramolecular hydrogen bonding comprising a six‐membered chelate ring. The N? H···O hydrogen bond causes an increase of the 1J(N,H) coupling constant by 2–4 Hz and high‐frequency shift of the 15N signal by 9–10 ppm despite of the lengthening of the relevant N? H bond. These experimental trends are substantiated by gauge‐independent atomic orbital and density functional theory calculations of the shielding and coupling constants in the 3,3‐bis(isopropylamino)‐1‐(aryl)prop‐2‐en‐1‐one (12) for conformations with the Z‐ and E‐orientations of the carbonyl group relative to the N? H group. The effects of the N? H···O hydrogen‐bond on the NMR parameters are analyzed with the atoms‐in‐molecules (AIM) and natural bond orbital (NBO) methods. The AIM method indicates a weakening of the N? H···O hydrogen bond as compared with that of 1,1‐di(pyrrol‐2‐yl)‐2‐formylethene (13) where N? H···O hydrogen bridge establishes a seven‐membered chelate ring, and the corresponding 1J(N,H) coupling constant decreases. The NBO method reveals that the LP(O) →σ*N? H hyperconjugative interaction is weakened on going from the six‐membered chelate ring to the seven‐membered one due to a more bent hydrogen bond in the former case. A dominating effect of the N? H bond rehybridization, owing to an electrostatic term in the hydrogen bonding, seems to provide an increase of the 1J(N,H) value as a consequence of the N? H···O hydrogen bonding in the studied diaminoenones. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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