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71.
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We calculated the one-center atomic integral of the spin—spin interaction with respect to Slater orbitals where we have included a two-electron correlation function that we used previously to calculate the hyperfine splitting of the 23P state of He. The ZFS of the benzene molecule was calculated from this value of the one-center integral and by using the Mulliken approximation combined with a previously introduced approximation for extimating the other integrals. The calculation was performed for two different non-hexagonal configurations I and II, the results are D1 = 0.132 cm?1 and DII = 0.143 cm?1. The experimental value is D = 0.158 cm?1. 相似文献
73.
Complexes of 2, 6‐bis(hydroxymethyl)pyridine (dhmp) with different CuII salts [CuCl2·6H2O, Cu(ClO4)2·6H2O, Cu(NO3)2·3H2O, Cu(CH3COO)2·H2O] are prepared ( 1 — 5 , respectively), studied by IR, and their crystal structures reported. Dependent on the anion kind, influences on the distortion of the co‐ordination polyhedron, the distribution of donor sites, the formation of a mono‐ or binuclear complex, and the resultant packing structure of the complex are observed, although in no case the counterions of the used CuII salts or water of hydration were found in the co‐ordination sphere. Crystal structures of 1 — 5 indicate hexaco‐ordination of the CuII ions with N2O4‐environment and show that 1 — 4 are mononuclear 2:1 (L:M) complexes, but 5 is a binuclear 4:2 complex. Crystallization of Cu(ClO4)2·6H2O with dhmp yielded two different complexes ( 2 / 3 ). In 3 , one of the dhmp components is mono‐deprotonated and acts as an anionic ligand. The same behavior is found in 5 . Whereas in the neutral ligand complexes 1 , 2 and 4 the basal planes are occupied by O donors, and N atoms are in the axial positions of the octahedrons, in 3 and 5 the bases are formed by two O and two N donor atoms, and O atoms are in the axes. Moreover, complex 3 shows the N atoms in trans position, but 5 in cis position. The packing of the cationic complex units is typical of strong and weak H bond interactions involving the counterions and hydroxylic or aromatic hydrogen atoms to yield complex network structures. 相似文献
74.
Tobias Gruber Max Peukert Diana Schindler Wilhelm Seichter Edwin Weber Petra Bombicz 《Journal of inclusion phenomena and macrocyclic chemistry》2008,62(3-4):311-324
Three lower rim n-propyl substituted calix[4]arenes (1–3) with varied number and position of the modifying groups have been prepared. Inclusion compounds (five species) involving different kinds of guest solvents have been isolated. Their X-ray crystal structures were determined and comparatively discussed using isostructurality calculations. Two of the inclusion compounds obtained (1a and 1b) are polymorphs containing the same host and guest molecules in equal stoichiometric ratio but different Z′ values caused by a phase transition around 140 K. The inclusion compounds 2a and 2b refer to the interesting case of a mixed solvent complex while 3a allows studying the effect of full lower rim n-propyl substitution. 相似文献
75.
76.
Elena Pahonu Maria Proks Sergiu Shova Gina Lupacu Diana‐Carolina Ilie tefania‐Felicia Brbuceanu Laura‐Ileana Socea Mihaela Badea Virgil Punescu Dorin Istrati Aurelian Gulea Doina Drgnescu Cristina Elena Dinu Pîrvu 《应用有机金属化学》2019,33(11)
A series of Cu(II), Co(II), Pd(II), Pt(II), Zn(II), Cd(II) and Fe(III) complexes were designed and synthesized using Schiff base 1‐phenyl‐2,3‐dimethyl‐4‐(N‐3‐formyl‐6‐methylchromone)‐3‐pyrazolin‐5‐one (HL). The new metal complexes were investigated using various physicochemical techniques including elemental and thermal analyses, molar electric conductivity and magnetic susceptibility measurements, as well as spectroscopic methods. Also, the crystal structures of ligand HL and the Pd(II) complex were determined using single‐crystal X‐ray diffraction analysis. For all compounds, the antimicrobial activity was studied against a series of standard strains: Staphylococcus aureus, Bacillus cereus, Enterococcus faecalis, Escherichia coli, Acinetobacter baumannii, Candida albicans, Candida krusei and Cryptococcus neoformans. The in vitro antiproliferative activity of the ligand and complexes was evaluated against ten cancer cell lines: MSC, A375, B16 4A5, HT‐29, MCF‐7, HEp‐2, BxPC‐3, RD, MDCK and L20B. At 10 μM concentration a significant cytotoxic effect of the Co(II), Pd(II) and Cd(II) complexes was observed against B16 4A5 murine melanoma cells. The Zn(II) complex is active against HEp‐2, RD and MDCK cancer cell lines, where IC50 values vary between 1.0 and 77.6 and for BxPC‐3 the activity index versus doxorubicin is 3.7 times higher. 相似文献
77.
Thomas?Sch?nherr Edwin?WeberEmail author Gerd?Rheinwald Wilhelm?Seichter 《Journal of inclusion phenomena and macrocyclic chemistry》2005,51(1-2):93-96
A new onium salt host molecule 1 featuring a spiro-type ammonium backbone was synthesized and shown to form a crystalline inclusion compound with chloroform, 1 · chloroform (1:2), the crystal structure of which is reported. The host molecular interactions including C–H···Br, Cl···Cl and aromatic stacking contacts are typical of the packing structure.Supplementary Data relevant to this publication have been deposited with the Cambridge Crystallographic Data Centre as supplementary publication No. CCDC 229358.This revised version was published online in July 2005 with a corrected issue number. 相似文献
78.
Felicia Phei Lin Lim Nathan R. Halcovitch Edward R.T. Tiekink Anton V. Dolzhenko 《Tetrahedron》2018,74(15):1868-1879
A series of 5-aza-9-deaza- analogues of purine was effectively prepared using highly selective annulation of 1,3,5-triazine ring onto 5-aminopyrazole-4-carboxylates via a one-pot, multicomponent, microwave-assisted approach. The products were obtained in good yields and high purity. This catalyst-free method was demonstrated to be scalable and highly reproducible in different microwave reactors. Some structural features of the prepared compounds were studied in details using dynamic NMR spectroscopy and X-ray crystallography. 相似文献
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