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1.
A simple model consisting of two electronic levels and one vibrational mode (phonon) was theoretically studied. The electronic-vibrational interaction was linear in the vibrational displacement. The vibrational mode was taken in the harmonic approximation and was attached to the thermal bath formed by the ambient environment. The kinetic constants of the vibrational dissipation were of the second order in the vibrational-bath coupling and were taken in the Markovian limit. Although, depending on the parameters of the model, different curves of the non-radiative vibration-induced excited state decay were obtained, in general, three time intervals, corresponding to different physical behaviour, were found. In the short-time interval, small oscillations superimposed on the excited state decay were observed. They were determined by the vibrational frequency and influenced by electronic-vibrational coupling. In the middle-time interval, almost quasi-exponential decay was detected; its rate constant increased with stronger electronic-vibrational interaction and speed of vibrational relaxation. In the long-time interval, the decay was very slow and, under special conditions, even an asymptotic non-zero excited state population was observed. Its value increased with the strength of the off-diagonal electron-vibrational coupling. Links of the parameters of the model with quantum chemical terms were estimated. 相似文献
2.
D. V. Makarov A. T. Belyaevskii Yu. P. Men’shikov D. P. Nesterov M. F. Yusupova 《Russian Journal of Applied Chemistry》2007,80(2):175-180
Behavior of a skeleton silicate, nepheline, in the reaction of fluorination with ammonium hydrofluoride was studied by means of differential-thermal, X-ray phase, and chemical analyses, IR spectroscopy, and scanning electron microscopy. 相似文献
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4.
Miroslav Menšík 《Czechoslovak Journal of Physics》1998,48(4):469-475
A time solution of the excimer-ion pair system is presented here with a special attention to the time asymptote.
Presented at the Czech-Israeli-German Symposium “Dynamical Processes in Condensed Molecular Systems”, Prague, Czech Republic,
26–30 May 1997.
This work was supported by the grant No. C 1050601 of the Grant Agency of the Academy of Sciences of the Czech Republic. 相似文献
5.
A model is proposed for magnetic ordering in Fe/Cr-type multilayers substantially above the Néel temperature of bulk chromium. Redistribution of the charge (and, hence, spin) density near the Fe/Cr interfaces gives rise to the formation of an essentially inhomogeneous spin-density-wave (SDW) state in the chromium spacer. The spatial structure of the antiferromagnetic order parameter in thick spacers is described. The SDW contribution to the effective exchange coupling between the moments in adjacent iron layers is calculated. The data obtained are used in the interpretation of experimental data on the tunneling spectroscopy of trilayers and neutron diffraction from Fe/Cr superlattices. 相似文献
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研究了酚醛型吸附树脂在水体系中对吡啶和N,N-二甲基苯胺的静态和动态吸附行为.结果表明,在水中树脂对吡啶和N,N-二甲基苯胺的吸附主要以疏水吸附机理进行;吸附吡啶和N.N-二甲基苯胺的初始阶段,即达到38.3~48.9%平衡吸附时,吸附速率数据和半经验速率方程很吻合:酚醛型吸附树脂等温吸附吡啶和N,N-二甲基苯胺的平衡吸附数据符合Langmuir方程,相关系数在0.99以上,酚醛型吸附树脂吸附吡啶和N,N-二甲基苯胺属单分子层吸附:用80%的乙醇溶液作洗脱剂来洗脱吸附吡啶已达饱和的JDW-2树脂,效果是很理想的.在3.6个床体积内洗脱率达91.52%,4.8个床体积内洗脱率达到94.85%。表明酚醛型吸附树脂具有优良的洗脱性能. 相似文献
8.
钙钛矿型La_((1 x)/2)Sr_((1-x)/2)Co_(1-x)Cu_xO_3催化CO氧化活性与表征 总被引:1,自引:0,他引:1
研究了钙钛矿型LaSrCoCu_xO_3催化剂对CO氧化反应的催化活性及其表面氧的催化作用.结果表明,x=0.4的催化剂对CO氧化具有最高催化活性,常压及本实验条件下CO完全氧化的最低温度为168℃;催化剂均为氧缺陷化合物,吸附于表面晶格氧缺陷上的吸附氧是CO氧化反应的活性氧物种;并发现催化剂中存在有非常价态的C04 ,认为CO氧化反应是通过吸附氧调变Co3 和Co4 价态而进行. 相似文献
9.
A. I. Men’shikova T. G. Evseeva K. S. Inkin Yu. O. Skurkis S. S. Ivanchev 《Russian Journal of Applied Chemistry》2006,79(10):1660-1665
Emulsion copolymerization of methyl methacrylate and N-vinylformamide in the presence of azo initiators and dextran as a polymeric stabilizer was analyzed with the aim to prepare monodisperse polymer microspheres with a polyfunctional surface. Hydrolysis of comonomer units and cationic groups of the initiator residues in the surface layer of the particles to give amphoteric surfaces containing carboxy and amino groups was studied. The optimal conditions of formation of monodisperse microspheres with diameter varied in the 340–660 nm range and the conditions of their hydrolysis, which allow direct control of the amount and nature of functional groups on their surface, were found. 相似文献
10.