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51.
Oksana Pietraszkiewicz Marek Pietraszkiewicz 《Journal of inclusion phenomena and macrocyclic chemistry》1999,35(1-2):261-270
Lipophilic calix[4]resorcinarenes, derived from lauryl aldehyde and resorcinol, are strongly adsorbed on the modified silica gel RP-18 for HPLC chromatography, while their solutions are passed through the column. The calix[4]resorcinarene-coated RP-18 phases were found to be useful beds for HPLC separation of uracil, thymine and cytosine. 相似文献
52.
We investigate properties of square-Gaussian stochastic processes. These processes are formed by quadratic forms of Gaussian processes or by limits in the mean square of quadratic forms of Gaussian processes. Special classes of these processes are determined and investigated. For processes from these classes estimates of large deviation probability are obtained. These estimates we use to estimate the probability that Gaussian vector-valued process leave some region on some interval of time. We construct asymptotic confidence regions for estimates of covariance functions of vector-valued Gaussian processes. Criterion of hypothesis testing on covariance functions of these processes is constructed. 相似文献
53.
Henrikh Altshuler Elena Ostapova Oksana Fedyaeva Lidiya Sapozhnikova Olga Altshuler 《Macromolecular Symposia》2002,181(1):1-4
The novel network polymers 2a-2d based on calix[4]resorcinarene derivatives were obtained with yields 2a: 80%, 2b: 90%, 2c: 70%, 2d: 70%. Polymers 2a and 2b containing fragments of tetramethylcalix[4]resorcinarene or tetraphenylcalix[4]resorcinarene as a repeating units were synthesized by condensation cis-tetramethylcalix[4]resorcinarene or cis-tetraphenylcalix[4]resorcinarene with formaldehyde. Polymers 2c and 2d containing fragments of furylcalix[4]resorcinarene were obtained by condensation of formaldehyde with products of calix[4]resorcinarene and furfural interaction. The IR spectra and sorption properties of the polymers were researched. It is found out that 2a-2d can participate in the cation-exchange reaction. 相似文献
54.
Organic and polymeric driving circuits may be a possible alternative to realize low cost flexible and large area flat panel displays. Recent efforts have been directed to the discovery of solution processable polymeric semiconductors for the ease of fabrication and low cost. In this paper, we report the investigation of various 3‐substituted regioregular polythiophenes as active semiconductors for field‐effect transistors. The best transistor performance has been found with regioregular poly(3‐heaxylthiophene). The difference in their device performance was correlated to the structure and morphological behavior of these regioregular polythiophenes. 相似文献
55.
Yaroslav O. Tokaychuk Yaroslav E. Filinchuk Anatoliy O. Fedorchuk Oksana I. Bodak 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(12):i125-i127
Trisamarium digallide tristannide crystallizes with a partially ordered Pu3Pd5‐type structure in space group Cmcm. In a single crystal of Sm3Ga1.89(4)Sn3.11(4), the 8g position is mostly occupied by Sn atoms (93% Sn and 7% Ga), while the 4c and 8f positions are occupied by a Ga/Sn statistical mixture. The evolution of the structure as a function of the Ga content has been studied by X‐ray powder diffraction on ten Sm3Ga5−xSnx samples. It is shown that the 8g position remains occupied essentially exclusively by Sn atoms within the whole homogeneity range, with x ranging from 2.52 to 4.20. 相似文献
56.
Vitalina M. Nikitina Oksana V. Nesterova Vladimir N. Kokozay Viktoriya V. Dyakonenko Oleg V. Shishkin Julia Jezierska 《Polyhedron》2009
Four new heterometallic Cu(II)/Cr(III) complexes with N,N-dimethylethylenediamine (dmen) and its novel Schiff-base derivatives, N′-[(1Z)-3-amino-1,3-dimethylbutylidene]-N,N-dimethylethane-1,2-diamine (dmenac) and N′-((1Z)-3-{[2-(dimethylamino)ethyl]amino}-1,3-dimethylbutylidene)-N,N-dimethylethane-1,2-diamine (dmen2ac), have been easily prepared by self-assembly and characterized by spectroscopic methods and single crystal X-ray analysis. The structures of all the complexes are assisted by numerous hydrogen bonds that provide a web of interactions and mould the supramolecular architectures of the compounds. Variable-temperature (1.8–300 K) magnetic susceptibility measurements reveal Curie-Weiss paramagnetic behavior of all the compounds, supported by EPR studies. 相似文献
57.
M. M. Monchak A. V. Pavlyuk V. V. Kinzhibalo M. G. Mys’kiv 《Russian Journal of Coordination Chemistry》2009,35(6):405-410
The alkylation of ethylenediamine with allyl bromide in the presence of a fourfold (with respect to ethylenediamine) molar
amount of NaHCO3 in acetone with an ethanol admixture (15: 1) affords LBr2 · 2H2O (I), where L2+ is the N,N,N,N′,N′,N′-hexaallylethylenediaminium cation. Single crystals of complexes L[CuII(Br0.45Cl3.55)] (II), L[Cu4I(Br4.55Cl1.45)] (III), and L[Cu4IBr6] (IV) are prepared by ac electrochemical synthesis from an ethanolic solution of LBr2 · 2H2O, CuCl2 · 2H2O (or CuBr2) at copper wire electrodes. The crystal structures of compounds I–IV are determined by X-ray diffraction analysis. The crystals of complex I are monoclinic: space group P21/n, a = 8.544(3), b = 10.404(3), c = 13.350(4) ?, β = 97.29(3)°, V = 1177.2(6) ?3, Z = 2. The bromine anions in compound I are bonded to the L2+ cations and water molecules through hydrogen contacts (E)H…Br (E = O, C) of 2.57(3)–2.86(3) ?. The crystals of compounds
II–IV are triclinic: space group P
. For II: a = 8.762(4), b = 9.163(4), c = 16.500(6) ?, α = 95.62(4)°, β = 96.39(4)°, γ = 111.46(4)°, V = 1211.4(9) ?3, Z = 2; for III: a = 9.074(4), b = 9.435(4), c = 9.829(5) ?, α = 116.12(4)°, β = 104.14(4)°, γ = 100.22(4)°, V = 692.3(6) ?3, Z = 1; for IV isostructural III: a = 9.084(4), b = 9.404(4), c = 9.869(4) ?, α = 116.31(3)°, β = 104.00(3)°, γ = 100.37(3)°, V = 692.1(5) ?3, Z = 1. Unlike the isolated tetrahedral CuX42− anion in structure II, an original chain anion (Cu4X62−)
n
is observed in the structures of π complexes III and IV.
Original Russian Text ? M.M. Monchak, A.V. Pavlyuk, V.V. Kinzhibalo, M.G. Mys’kiv, 2009, published in Koordinatsionnaya Khimiya,
2009, Vol. 35, No. 6, pp. 414–419. 相似文献
58.
Yu. I. Slyvka V. V. Kinzhibalo T. Lis B. M. Mykhalichko M. G. Mys’kiv 《Russian Journal of Coordination Chemistry》2009,35(4):307-311
A reaction of but-2-yne-1,4-diol with CuCl in a concentrated aqueous solution of piperazinium dichloride gave the π-complex
(PipH2)[CuCl2(HOCH2C≡CCH2OH)]2 · H2O ((PipH2)2+ is the piperazinium cation). The complex was examined by X-ray diffraction analysis (space group P
, a = 7.355(1) ?, b = 10.3572(8) ?, c = 13.632(2) ?, α = 101.055(9)°, β = 95.350(1)°, γ = 101.875(9)°, Z = 2). The complex consists of two crystallographically independent anions [CuCl2(HOCH2C≡CCH2OH)]− and the biprotonated piperazinium cation. The trigonal environment of the Cu(I) atom in either complex anion includes is
made up of two Cl atoms and the C≡C bond. Apart from the hydrogen bonds N-H⋯O that imparts a directed character to the ionic
interaction Cat+⋯An−, the piperazinium cation with molecules of crystallization water with bridging function form the cross-linking hydrogen bonds
N-H⋯OH2 and OH-H⋯Cl.
Original Russian Text ? Yu.I. Slyvka, V.V. Kinzhibalo, T. Lis, B.M. Mykhalichko, M.G. Mys’kiv, 2009, published in Koordinatsionnaya
Khimiya, 2009, Vol. 35, No. 4, pp. 311–315. 相似文献
59.
Oksana Makota Yuriy Trach Roman Leboda Jadwiga Skubiszewska-Zięba 《Central European Journal of Chemistry》2009,7(4):731-738
The catalytic effect of VSi2 on initial stages of the liquid-phase oxidation of cyclooctene by molecular oxygen was studied. The vanadium disilicide influences
on the oxidation process in the presence of hydroperoxide. VSi2 takes part in a radical formation stage by catalysis of hydroperoxide decomposition reaction. The catalyst was investigated
before and after reaction using FTIR spectroscopy. From the data obtained, the kinetic model of the catalytic oxidation process
was proposed and the equation for the reaction rate was derived. The equation has described all observed dependences of reaction
rate on the concentration of reactants and content of catalyst.
相似文献
60.
Dynamic surface tension of micellar solutions in the millisecond and submillisecond time range 总被引:1,自引:0,他引:1
Fainerman VB Mys VD Makievski AV Petkov JT Miller R 《Journal of colloid and interface science》2006,302(1):40-46
The analysis of the available bubble life times and dead times for the bubble pressure tensiometer BPA-1S shows that dynamic surface tensions can be measured also for surfactant solutions at concentrations many times higher than the corresponding CMC. For the three nonionic surfactants Triton X-100, Triton X-45, and C14EO8 experiments are performed for solutions with a concentration of up to 200 times the CMC (C14EO8). Comparison of the experimental data with micelle kinetics models yields rate constants for the fast micelle dissolution process, which are in a good agreement with values obtained by other experimental methodologies. 相似文献