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1.
2.
Alexander Apelblat Emanuel Manzurola Zoya Orekhova 《Journal of solution chemistry》2006,35(6):879-888
Conductivity measurements in dilute aqueous solutions of L-ascorbic acid, sodium-L-ascorbate, magnesium-L-ascorbate, calcium-L-ascorbate and ferrous-L-ascorbate were performed in the (288.15 to 323.15) K temperature range. The limiting molar conductances of the ascorbic anion, λ∘(HAsc−, T), and the dissociation constants of ascorbic acid, K(T), were derived by the use of the Debye-Hückel equation for the activity coefficients and the Onsager and Quint and Viallard conductivity equations. 相似文献
3.
Anna Worobiec Lucyna Samek Zoya Spolnik Velichka Kontozova Elzbieta Stefaniak René Van Grieken 《Mikrochimica acta》2006,156(3-4):253-261
The St. Michael Archangel’s Church in Szalowa, Poland, was selected for closer investigation with respect to the indoor/outdoor
air exchange and its influence on the air quality and work arts preservation. Chemical composition, size and abundance of
particulate matter and concentration of gases NO2, SO2, O3 inside and outside the church were determined. To study seasonal variation of the weather condition (temperature, inversion
level, wind direction) and the influence of seasonal sources of the air pollution (like heating of the nearby houses), samples
were collected in winter and summer time. It was stated that suspended particulate matter inside the wooden church has in
general an outdoor source. Several groups of particles were distinguished such as the organic ones, soil dust, nitrates and
sulphates. In case of organic and soil dust particles, the concentration inside was higher than outside. From the results,
in comparison to literature data, one can conclude that accumulation of particulate suspended matter in the church is more
intense than in other types of buildings. Gaseous pollutants were detected but their concentration was negligible. 相似文献
4.
I. V. Ajinenko Y. A. Belokopitov A. A. Borovikov P. V. Chliapnikov Z. C. Garutchava L. N. Gerdyukov S. A. Gumenuk V. V. Kniazev A. I. Kurnosenko L. V. Orekhova L. P. Petrovikh V. N. Riadovikov A. G. Tomaradse V. A. Uvarov A. P. Vorobjev N. S. Amaglobely Ch. S. Chochiachvili M. Barth E. A. De Wolf M. Van Immerseel F. Verbeure CERN - USSR Collaboration 《Zeitschrift fur Physik C Particles and Fields》1984,25(2):103-114
We present final results on inclusive production ofK *+(890),K *+(1430) andK *?(890) in \(\bar K^ + p\) interactions at 32 GeV/c, based on a statistics of ~27 events/μb. Total cross sections,p T -andx-dependence of inclusive distributions are compared with experiments at other energies and with the Lund fragmentation model. Spin density matrix elements of theK *+(890) are also discussed. The results suggest that “recombination” of both initial state valence quarks \(\bar s\) andu of theK + intoK *+(890), responsible in the Lund model for ~45% of theK *+(890) cross section, is strongly suppressed. 相似文献
5.
Alexander Apelblat Emanuel Manzurola Zoya Orekhova 《Journal of solution chemistry》2007,36(8):1023-1035
Conductivity measurements of glutaric acid and disodium glutarate in dilute aqueous solutions were performed in the 288.15
to 323.15 K temperature range. The limiting equivalent conductances of glutarate anions, λ
o(HGlut−,T) and λ
o(1/2Glut2−,T), and the dissociation constants of glutaric acid, K
1(T) and K
2(T), were derived by the use of the Onsager and the Quint and Viallard conductivity equations. The applied molecular model was
successfully confirmed by analyzing the conductivities of sodium hydrogen glutarate at 298.15 K. 相似文献
6.
7.
M. M. Ermilova N. V. Orekhova E. V. Skakunova V. M. Gryaznov 《Russian Chemical Bulletin》1988,37(4):637-640
1. | In the course of catalytic hydrogenation reactions of cyclopentadiene, cyclooctadiene, and isoprene; and in the catalytic hydrogenolysis of propane, all of which proceed at 373–573 K, a.catalytic etching of a palladium-ruthenium membrane catalyst is taking place; it is determined by the nature of the reagents. |
2. | An oxidative-reductive treatment changes the surface structure, the catalytic activity, and the hydrogen permeability to a much lesser degree than when such a treatment is alternated with actual catalytic reactions. |
3. | A heat treatment followed by a subsequent rapid cooling from temperatures above the recrystallization temperature, increases significantly the activity of a palladium-ruthenium membrane catalyst in the hydrogenolysis of propane. |
8.
Zoya A. Solodovnikova Sergey F. Solodovnikov 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(7):i53-i56
The crystal structures of dirubidium heptaoxodimolybdate, Rb2Mo2O7, and dicaesium heptaoxodimolybdate, Cs2Mo2O7, in the space groups Ama2 and P21/c, respectively, have been determined for the first time by single‐crystal X‐ray diffraction. The structures represent two novel structure types of monovalent ion dimolybdates, A2Mo2O7 (A = alkaline elements, NH4, Ag or Tl). In the structure of Rb2Mo2O7, Mo atoms are on a twofold axis, on a mirror plane and in a general position. One of the Rb atoms lies on a twofold axis, while three others are on mirror planes. Two O atoms attached to the Mo atom on a mirror plane are located on the same plane. Rubidium dimolybdate contains a new kind of infinite Mo–O chain formed from linked MoO4 tetrahedra and MoO6 octahedra alternating along the a axis, with two terminal MoO4 tetrahedra sharing corners with each octahedron. The chains stack in the [001] direction to form channels of an approximately square section filled by ten‐coordinate Rb ions. Seven‐ and eight‐coordinate Rb atoms are located between chains connected by a c translation. In the structure of Cs2Mo2O7, all atoms are in general positions. The MoO6 octahedra share opposite corners to form separate infinite chains running along the c axis and strengthened by bridging MoO4 tetrahedra. The same Mo–O polyhedral chain occurs in the structure of Na2Mo2O7. Eight‐ to eleven‐coordinate Cs atoms fill the space between the chains. The atomic arrangement of caesium dimolybdate has an orthorhombic pseudosymmetry that suggests a possible phase transition P21/c→Pbca at elevated temperatures. 相似文献
9.
Perepichka IF Popov AF Orekhova TV Bryce MR Andrievskii AM Batsanov AS Howard JA Sokolov NI 《The Journal of organic chemistry》2000,65(10):3053-3063
2,4,5,7-Tetranitro-9-fluorenone (1b) reacts readily with n-butanethiol in dipolar aprotic solvents with selective substitution of nitro groups by butylsulfanyl groups in positions 2 and 7 (2, 3); the 2,5-isomer 4 was formed only as a minor product (<1%). Condensation of fluorenones 2-4 with malononitrile yielded 9-dicyanomethylene derivatives 5-7, which showed strong intramolecular charge transfer (lambda approximately 510-560 nm) and were found to sensitize the photoconductivity of carbazole-containing polymer films. Oxidation of sulfides 2-4 gave sulfoxide 8 or sulfones 9-11, which then were converted into their corresponding dicyanomethylene derivatives 12-15. All these novel acceptors showed three reversible single-electron reduction waves (cyclic voltammetry) yielding radical anion, dianion, and radical trianion; moreover, acceptors 13-15 showed also a fourth reduction wave, representing reversible tetraanion formation. Substitution of the oxygen of the carbonyl group in the fluorenones by a dicyanomethylene group increased the thermodynamic stability (K(SEM) growth) of the radical anion; K(SEM) ranged from 3 x 10(5) to 3 x 10(9) M(-1). CV measurements characterize compounds 3, 4 (EA = 1. 86-1.89 eV) as poor acceptors, 2, 6-11 (EA = 2.13-2.31 eV) as moderate acceptors, and 5, 12-15 (EA = 2.53-2.66 eV) as strong electron acceptors. Charge-transfer complex (CTC) formation between acceptors 9, 10, 13, 14, and anthracene as a donor was monitored by the appearance of additional low-energy bands in the visible region (CTC bands) of their electron absorption spectra. Increasing the EA of the acceptors from 9-fluorenones to the corresponding 9-dicyanomethylenefluorenes increases the complexation constants K(CTC) by 2.5-3 times, while sulfonyl substituents present substantial steric hindrance for complexation (as compared to the nitro group), decreasing K(CTC) values. Two CTCs for acceptors 14 and 17 with tetrathiafulvalene (TTF) were obtained, and their structures were solved by single-crystal X-ray diffractometry, giving the stoichometries 14:TTF, 2:3, and 17:TTF:PhCl, 1:1:0.5. In the former complex the packing motif is a mixed.DDAD'A. stack; in the latter complex the D and A moieties form unusually close CT pairs, which pack in a herringbone motif. 相似文献
10.
Zoya?Orekhova Yonit?SambiraEmail author Emanuel?Manzurola Alexander?Apelblat 《Journal of solution chemistry》2005,34(7):853-867
Conductivity measurements of DL-pyroglutamic acid and sodium pyroglutamate in dilute aqueous solutions were performed in the 288.15–323.15 K temperature range. The limiting molar conductances of pyroglutamate anion, λo(pGlu−, T) and the dissociation constants of pyroglutamic acid, K(T) were derived from the Onsager, and the Quint and Viallard conductivity equations. Densities of aqueous solutions with molalities lower than 0.5 mol-kg−1 were determined at 5 K intervals from T = 288.15 K to 333.15 K. Densities served to evaluate the apparent molar volumes, V2,φ(m, T), the cubic expansion coefficients, α (m,T) and the changes of the isobaric heat capacities with respect to pressure, (∂ CP/∂ P)T,m. They were correlated qualitatively with the changes in the structure of water when pyroglumatic acid is dissolved in it. 相似文献