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1.
J. Zhuang W. Kunnmann L.M. Corliss J.M. Hastings R.O. Moyer 《Journal of solid state chemistry》1983,48(1):117-120
A powder neutron diffraction study of Eu1532IrD5 has shown it to be isostructural with Sr2IrD5 at room temperature. Unlike the latter compound, it does not undergo a deuterium-ordering transition at low temperatures. Magnetic scattering at helium temperatures confirms the suggestion that it becomes ferromagnetic below 20 K with a moment corresponding to that of divalent europium. 相似文献
2.
3.
Jian Zhuang Julius M. Hastings Lester M. Corliss R. Bau Chiau-Yu Wei R. O. Moyer Jr. 《Journal of solid state chemistry》1981,40(3):352-360
Neutron diffraction data have been collected on a powdered sample of Sr2IrD5 over a range of temperatures. The compound, which is cubic at room temperature, has been found to exhibit a gradual transformation to a tetragonal phase in the temperature range 200-140 K. As a result of the transition, deuterium atoms which randomly occupy sixfold positions in the cubic phase, become tetragonally ordered. A small fraction of the cubic phase remained untransformed at 4.2 K. Both the cubic and tetragonal structures are consistent with square pyramidal IrD5 units with average Ir---D distances of 1.714 and 1.718 Å, respectively. Agreement factors, R1, for the two structural analyses are 3.44 and 4.94%. 相似文献
4.
Andrei A. Gakh Bobby G. Sumpter Donald W. Noid Richard A. Sachleben Bruce A. Moyer 《Journal of inclusion phenomena and macrocyclic chemistry》1997,27(3):201-213
A computational neural network method was used for the prediction of stability constants of simple crown ether complexes. The essence of the method lies in the ability of a computer neural network to recognize the structure-property relationships in these host-guest systems. Testing of the computational method has demonstrated that stability constants of alkali metal cation (Na+, K+, Cs+)-crown ether complexes in methanol at 25 °C can be predicted with an average error of ±0.3 log K units based on the chemical structure of the crown ethers alone. The computer model was then used for the preliminary analysis of trends in the stabilities of the above complexes. 相似文献
5.
E. Makrlík P. Selucký P. Vaňura B. A. Moyer 《Journal of Radioanalytical and Nuclear Chemistry》2013,295(3):2171-2174
From extraction experiments and $ \gamma $ -activity measurements, the exchange extraction constants corresponding to the general equilibrium M+ (aq) + NaL+ (nb) ? ML+ (nb) + Na+ (aq) taking place in the two–phase water–nitrobenzene system (M+= Li+, H3O+, NH4 +; L = calix[4]arene-bis(t-octylbenzo-18-crown-6); aq = aqueous phase, nb = nitrobenzene phase) were evaluated. Furthermore, the stability constants of the ML+ complexes in nitrobenzene saturated with water were calculated; they were found to increase in the following cation order: H3O+ < Li+ < NH4 +. 相似文献
6.
From extraction experiments and $ \gamma $ -activity measurements, the exchange extraction constant corresponding to the equilibrium Tl+ (aq) + 1·Cs+ (org) ? 1·Tl+ (org) + Cs+ (aq) taking place in the two-phase water–phenyltrifluoromethyl sulfone (abbrev. FS 13) system (1 = calix[4]arene-bis(t-octylbenzo-18-crown-6); aq = aqueous phase, org = FS 13 phase) was evaluated as log K ex (Tl+, 1·Cs+) = 1.7 ± 0.1. Further, the extraordinarily high stability constant of the 1·Tl+ complex in FS 13 saturated with water was calculated for a temperature of 25 °C: log β org(1·Tl+) = 13.1 ± 0.2. Finally, by using quantum mechanical DFT calculations, the most probable structure of the cationic complex species 1·Tl+ was derived. In the resulting 1·Tl+ complex, the “central” cation Tl+ is bound by eight bond interactions to six oxygen atoms from the respective 18-crown-6 moiety and to two carbons of the corresponding two benzene rings of the parent receptor 1 via cation–π interaction. 相似文献
7.
8.
Sara A. Moyer 《Tetrahedron letters》2010,51(41):5430-145
An alcohol oxidation process using an air-stable iron tricarbonyl compound structurally similar to Shvo’s diruthenium bridging hydride was developed. Secondary benzylic and allylic alcohols are oxidized in high yields, and evidence for an Oppenauer-type mechanism is presented. 相似文献
9.
T G Levitskaia B A Moyer P V Bonnesen A P Marchand K Krishnudu Z Chen Z Huang H G Kruger A S McKim 《Journal of the American Chemical Society》2001,123(48):12099-12100
10.
CLAUDIA L. PARKER OSCAR N. VENTURA STAN K. BURT RAÚL E. CACHAU 《Molecular physics》2013,111(17):2659-2668
We present a general purpose QM-MM-MD engine (DYNGA) designed to test alternative hybrid Hamiltonians geared towards the treatment of problems of interest in structural biology including the use of experimental data constraints. In this first presentation we use DYNGA to explore the behaviour of a traditional QM-MM approach in the treatment of the water—water interaction. We find the potential energy hypersurface for the water dimer computed with the HF 4–31G*/TIP3P hybrid Hamiltonian tends to be too flat. We also explore the effect of using traditional QM-MM techniques on proton wires and conclude there is a need for improvement, possibly addressed by using polarizable force fields. 相似文献