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131.
A high-performance liquid chromatographic method is described for monitoring plasma concentrations of cinromide (3-bromo-N-ethylcinnamamide) and its de-ethylated metabolite. Carbamazepine levels can be easily measured by the same technique. The N-isopropyl analogue of cinromide is used as internal standard, and all compounds are easily separated on a reversed-phase column operated at 55 degrees with a small-diameter pre-column maintained at the same temperature. The extraction is rapid and generally applicable to plasma and urine samples that are to be analyzed by reversed-phase chromatography. Short- and long-term reproducibility studies show less than 4% relative standard deviation for replicate determinations for all drugs. Limits of quantitation are 10-20 ng/ml with an internal standard concentration of 3 micrograms/ml. Another metabolite of cinromide, 3-bromocinnamic acid, which may have some anticonvulsant effect, can be analyzed simultaneously by buffering the mobile phase and adding an ion-pairing reagent. 相似文献
132.
Unhindered phenylhydrazones form charge-transfer complexes with organic acceptors like tetracyanoethylene and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone. FT-IR determinations on starting hydrazones allow to predict the possibility of suitable molecular associations. 相似文献
133.
The varying stabilities of certain aminoindole radical cations toward oxidation with molecular oxygen have been studied. Oxidation leads to different products depending upon the environment around the N-amino nitrogen. A plausible reaction mechanism is proposed based on electronic and magnetic resonance spectroscopy. 相似文献
134.
3-Phenyl-2H-1, 4-benzoxazines 4-oxides are light sensitive compounds, irradiation leads to 3-phenyl-2H-1,4-benoxazines and to their 3-oxidized derivatives, whenever possible. Intermediate oxaziridines are formed during the photolysis and transformed into stable nitroxide radicals. The structure of these radicals was confirmed through peracid oxidation of 3-phenyl-2H-1,4-benzoxazines and 3-phenyl-3, 4-dihydro-2H-1,4-benzoxazines. A reaction mechanism is proposed on the basis of experimental observations. 相似文献
135.
Botti A Bruni F Imberti S Ricci MA Soper AK 《The Journal of chemical physics》2004,120(21):10154-10162
A neutron diffraction experiment with isotopic H/D substitution on four concentrated NaOH/H(2)O solutions is presented. The full set of partial structure factors is extracted, by combining the diffraction data with a Monte Carlo simulation. These allow to investigate both the changes of the water structure in the presence of ions and their solvation shells. It is found that the interaction with the solute affects the tetrahedral network of hydrogen bonded water molecules in a manner similar to the application of high pressure to pure water. The solvation shell of the OH(-) ions has an almost concentration independent structure, although with concentration dependent coordination numbers. The hydrogen site coordinates a water molecule through a weak bond, while the oxygen site forms strong hydrogen bonds with a number of molecules that is on the average very close to four at the higher water concentrations and decreases to about three at the lowest one. The competition between hydrogen bond interaction and Coulomb forces in determining the orientation of water molecules within the cation solvation shell is visible in the behavior of the g(NaHw)(r) function 相似文献
136.
Cis-trans photoisomerism of styrene is investigated from a theoretical point of view. Curves of the potential energy as a function of the rotation angle (ω) around the ethylenic bond were obtained for the ground state and a few excited states by the CIPSI PCILO method. The potential surface of the lowest excited singlet is found to have both an absolute minimum at ω = π/2 and a small relative minimum at ω = 0. These findings are consistent with the singlet mechanism for the direct cis-trans photoconversion. The origin of the two energy minima in the S1 potential surface is explained in terms of weights of the local excitations in the zero-order wavefunction. 相似文献
137.
Paolo Bruni Carla Conti Giorgio Tosi 《Monatshefte für Chemie / Chemical Monthly》1988,119(11):1311-1316
Competitive demethylation and redox reactions induced by 2,2-diphenyl-3,3-bi-3H-indole-1,1-dioxide,1 (dinitrone) on several nitrogen bearing compounds (pyridines, amides, indoles, hydrazones and amines) are reported.Es wird über kompetitive Demethylierungen und Redoxreaktionen an stickstoffhaltigen Verbindungen (Pyridine, Amide, Indole, Hydrazone und Amine) berichtet, die durch das Dinitron 2,2-Diphenyl-3,3-bi-3H-indol-1,1-dioxid induziert werden.
2,2-Diphenyl-3,3t-bi-3H-indol-1,1t-dioxid: Kompetitive Demethylierung und Redoxreaktionen相似文献
138.
V. Berbenni C. Milanese G. Bruni A. Marini 《Journal of Thermal Analysis and Calorimetry》2005,82(2):401-407
The thermal decomposition of gallium nitrate hydrate (Ga(NO3)3·xH2O) to gallium oxide has been studied by TG/DTG and DSC measurements performed at different heating rates. It is concluded
that 8 water molecules are present in the hydrate compound. The anhydrous gallium nitrate does not form at any temperature
as the reaction consists of coupled dehydration/decomposition processes that occur with a mechanism dependent on heating rate.
TG measurements performed with isothermal steps (between 31 and 115°C) indicate that Ga(OH)2NO3 forms in the first stage of the reaction. Such a compound undergoes further decomposition to Ga(OH)3 and Ga(NO3)O, compounds that then decompose respectively to Ga(OH)O and finally to Ga2O3 and directly to Ga2O3. Diffuse reflectance Fourier transform IR spectroscopy (DRIFTIR) has been of help in assessing that the reaction consists
of parallel dehydration/decomposition processes. 相似文献
139.
M M Rechler C B Bruni J M Podskalny R A Carchman 《Journal of supramolecular structure》1976,4(2):199-204
The addition of serum to density-inhibited human fibroblast cultures induced a wave of DNA synthesis, measured as [3H] thymidine incorporation into acid-precipitable material, beginning after 8-12 hr and reaching maximum levels of 16-24 hr. Addition of dibutyryl-3':5'-cyclic AMP (DBcAMP) together with serum inhibited [3H] thymidine incorporation by 75-95%. When DBcAMP was added for the first 4 hr of serum stimulation and then removed, the wave of DNA synthesis was not delayed. This suggested that serum could induce DNA synthesis even though cyclic AMP concentrations were maintained at high levels by DBcAMP during this initial period. These results are inconsistent with the hypothesis that it is the immediate transient reduction in 3':5'-cyclic AMP concentration following the addition of serum that triggers DNA synthesis. By contrast, DBcAMP added 8 hr after serum inhibited [3H] thymidine incorporation to the same extent as DBcAMP added at the same time as serum. This indicated that a step essential for DNA synthesis and occurring late in G1 was inhibited by high concentrations of 3':5'-cyclic AMP. 相似文献
140.
Derrick M Krakauer D Magill S Mikunas D Musgrave B Repond J Stanek R Talaga RL Zhang H Ayad R Bari G Basile M Bellagamba L Boscherini D Bruni A Bruni G Bruni P Cara Romeo G Castellini G Chiarini M Cifarelli L Cindolo F Contin A Corradi M Gialas I Giusti P Iacobucci G Laurenti G Levi G Margotti A Massam T Nania R Nemoz C Palmonari F Polini A Sartorelli G Timellini R Zamora Garcia Y Zichichi A Bargende A Crittenden J Desch K Diekmann B Doeker T Eckert M Feld L Frey A Geerts M Geitz G Grothe M 《Physical review letters》1995,75(6):1006-1011