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1.
The near-infrared (NIR) absorption of toluene-sulfonate-diacetylene crystals (PTS) has been investigated during thermal polymerization. It is shown by comparative NIR and IR spectroscopy of deuterated and of protonated PTS at various temperatures, that these absorptions are vibronic in nature. They can be assigned unambiguously to distinct parts of the molecule. No low-lying electronic state has been found. 相似文献
2.
The title molecule, 2,2';9',2'-ter[1,10]phenanthroline can be prepared from 2,9-dichloro-1,10-phenanthroline in three steps through the corresponding diacetyl intermediate. The ligand acts as a hexadentate with K+, while two molecules form a trinuclear, helical complex with Cu(I), which evidences pi-stacking interactions and Cu-Cu distances of 3.01-3.04 A. Electrochemical analysis shows a strong interaction between the Cu(I) centers. 相似文献
3.
Burford N Cameron TS Clyburne JA Eichele K Robertson KN Sereda S Wasylishen RE Whitla WA 《Inorganic chemistry》1996,35(19):5460-5467
The phosphadiazonium cation [MesNP](+) reacts quantitatively with the fluorenylide anion, MesNH(2), and MesOH (Mes = 2,4,6-tri-tert-butylphenyl), resulting in formal insertion of the N-P moiety into the H-Y (Y = C, N, O) bonds. Specifically, reaction of MesNPCl with fluorenyllithium gives the aminofluorenylidenephosphine [crystal data: C(31)H(38)NP, monoclinic, P2(1)/c, a = 9.568(8) ?, b = 24.25(2) ?, c = 11.77(1) ?, beta = 101.38(8) degrees, Z = 4]. Similarly, reaction of [MesNP][GaCl(4)] with MesNH(2) gives the diaminophosphenium salt [MesN(H)PN(H)Mes][GaCl(4)] [crystal data: C(36)H(60)Cl(4)GaN(2)P, monoclinic, C2/c, a = 24.921(2) ?, b = 10.198(4) ?, c = 16.445(2) ?, beta = 93.32(1) degrees, Z = 4], and reaction with MesOH gives the first example of an aminooxyphosphenium salt [MesN(H)POMes][GaCl(4)]. It is proposed that the reactions involve nucleophilic attack at phosphorus followed by a 1,3-hydrogen migration from Y to N. Experimental evidence for the formation of sigma-complex intermediates is provided by the isolation of [MesNP-PPh(3)][SO(3)CF(3)] [crystal data: C(37)H(44)F(3)NO(3)P(2)S, triclinic, P&onemacr;, a = 10.663(1) ?, b = 19.439(1) ?, c = 10.502(1) ?, alpha = 103.100(7) degrees, beta = 113.311(7) degrees, gamma = 93.401(7) degrees, Z = 2]. As part of the unequivocal characterization of the aminooxyphosphenium salt, detailed solid-state (31)P NMR studies and GIAO calculations on the phosphenium cations have been performed. Contrary to popular belief, the phosphorus shielding in dicoordinate cations is not caused by the positive charge but results from efficient mixing between the phosphorus lone pair and pi orbitals. 相似文献
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6.
Dr. Dominik Raiser Dr. Klaus Eichele Dr. Hartmut Schubert Prof. Dr. Lars Wesemann 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(56):14073-14080
The reaction of the intramolecular germylene-phosphine Lewis pair (o-PPh2)C6H4GeAr* ( 1 ) with Group 15 element trichlorides ECl3 (E=P, As, Sb) was investigated. After oxidative addition, the resulting compounds (o-PPh2)C6H4(Ar*)Ge(Cl)ECl2 ( 2 : E=P, 3 : E=As, 4 : E=Sb) were reduced by using sodium metal or LiHBEt3. The molecular structures of the phosphine-stabilized phosphinidene (o-PPh2)C6H4(Ar*)Ge(Cl)P ( 5 ), arsinidene (o-PPh2)C6H4(Ar*)Ge(Cl)As ( 6 ) and stibinidene (o-PPh2)C6H4(Ar*)Ge(Cl)Sb ( 7 ) are presented; they feature a two-coordinate low-valent Group 15 element. After chloride abstraction, a cyclic germaphosphene [(o-PPh2)C6H4(Ar*)GeP] [B(C6H3(CF3)2)4] ( 8 ) was isolated. The 31P NMR data of the germaphosphene were compared with literature examples and analyzed by quantum chemical calculations. The phosphinidene was treated with [iBu2AlH]2, and the product of an Al−H addition to the low-valent phosphorus atom (o-PPh2)C6H4(Ar*)Ge(H)P(H)Al(C4H9)2 ( 9 ) was characterized. 相似文献
7.
Thomas B Paasch S Steuernagel S Eichele K 《Solid state nuclear magnetic resonance》2001,20(3-4):108-117
In 31P MAS NMR spectra of chlorocyclophosphazenes, characteristic splittings have been observed for PCl or PCl2 groups. At different applied magnetic fields, the fine structure and total width of the patterns change in a characteristic way, demonstrating that the splittings are due to indirect spin–spin and residual dipolar interactions with the chlorine nuclei directly bonded to phosphorus. For trans-nongeminal N3P3Cl3(NMe2)3 and N3P3Cl6 as examples, the spectra have been analyzed to obtain information on chlorine nuclear quadrupole coupling constants and 35,37Cl, 31P indirect spin–spin coupling constants. Neglect of these interactions may result in misinterpretations of the multiplicity in 31P MAS spectra of chlorophosphazenes. 相似文献
8.
R. Eichele W. Kern R. P. Huebener 《Applied Physics A: Materials Science & Processing》1981,25(2):95-103
We have studied the influence of oxygen on the superconducting properties of thin films of lead, indium and tin deposited
on glass or sapphire substrates. In addition, the morphological microstructure was investigated by scanning electron microscopy.
The film thickness was 1.0 μm, and the partial pressure of O2 during the film deposition was raised up to 1×10−4 Torr. In all three materials the development of a granular structure and a strong increase in the residual electric resistivity
was observed due to the O2-treatment. Whereas in the Pb films no change of the critical temperature was found, the In films deposited on glass substrates
showed a slight increase ofT
c due to the oxygen. The strongest increase ofT
c (up to 8%) was observed in the O2-treated Sn films. These results are discussed in terms of the McMillan theory. From our measurements of the critical current
densityj
c we conclude that edge pinning is dominant in the undoped films. All three materials showed a strong increase ofj
c due to the O2-treatment which must be interpreted in terms of bulk pinning. 相似文献
9.
A comprehensive investigation of selenium chemical shift tensors is presented. Experimentally determined chemical shift tensors were obtained from solid-state 77Se NMR spectra for several organic, organometallic, or inorganic selenium-containing compounds. The first reported indirect spin-spin coupling between selenium and chlorine is observed for Ph(2)SeCl(2) where 1J(77Se,35Cl)iso is 110 Hz. Selenium magnetic shielding tensors were calculated for all of the molecules investigated using zeroth-order regular approximation density functional theory, ZORA DFT. The computations provide the orientations of the chemical shift tensors, as well as a test of the theory for calculating the magnetic shielding interaction for heavier elements. The ZORA DFT calculations were performed with nonrelativistic, scalar relativistic, and scalar with spin-orbit relativistic levels of theory. Relativistic contributions to the magnetic shielding tensor were found to be significant for (NH4)2WSe4 and of less importance for organoselenium, organophosphine selenide, and inorganic selenium compounds containing lighter elements. 相似文献
10.