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71.
Senka Djakovi Ljubica Glava‐Obrovac Jasmina Lapi Silvija Mara
i Juraj Kirchofer Marija Kneevi Marijana Juki Silvana Rai‐Mali 《应用有机金属化学》2021,35(1)
Mono‐ ( 3a – 3e and 4a – 4e ) and bis‐ferrocene ( 5a – 5e and 6a – 6e ) conjugated 5‐substituted uracil derivatives that are bridged by 1,2,3‐triazole linker were synthesized. The impact of ferrocene unit and spacer between ferrocene and triazole on radical scavenging potency was observed. Bis‐ferrocenyl uracil derivatives exhibited better antiproliferative activities than their mono‐ferrocenyl analogs. Bis‐ferrocenyl methyl‐ ( 5b ) and halogen‐substituted ( 5e , 6c , and 6d ) uracil derivatives showed pronounced and selective cytostatic activities on colon adenocarcinoma (CaCo‐2) and Burkitt lymphoma (Raji) cells, with higher potency and selectivity than the reference drug 5‐fluorouracil. Generation of reactive oxygen species (ROS) in CaCo‐2 and Raji cells when treated with compounds 5b , 5e , and 6d was observed. Bis‐ferrocenyl 5‐chlorouracil 6c induced significant disruption in mitochondrial membrane potential that is accompanied by activation of apoptosis in CaCo‐2, Raji, and acute lymphoblastic leukemia (CCRF‐CEM) cells, while 6d caused mitochondrial dysfunction and apoptosis induction in CaCo‐2 and Raji cells. Potent antiproliferative activity of 6c and 6d could be associated with mitochondrial membrane potential disruption accompanied by apoptosis induction. Our findings highlighted 6c and 6d with potent and selective antiproliferative activity on CaCo‐2, Raji, and CCRF‐CEM cells that may be associated with targeting cancer cell mitochondria, as a molecular target. 相似文献
72.
Slobodan??iri?Email authorView authors OrcID profile Violeta?Miti? Sne?ana?Jovanovi? Marija?Ili? Jelena?Nikoli? Gordana?Stojanovi? Vesna?Stankov Jovanovi? 《Mikrochimica acta》2018,185(12):556
The authors report on a novel sorbent (thermally treated natural zeolite; clinoptilolite) for use in dispersive micro-solid phase extraction (D-μ-SPE) of polycyclic aromatic hydrocarbons (PAHs) from water samples. The method was applied to the D-μ-SPE of 16 priority PAHs which then were quantified by gas chromatography with mass spectrometric detection (GC-MS). The method was validated in terms of specificity and selectivity, linearity and linear range, accuracy, precision, uncertainty, limits of detection and quantification. Figures of merit include (a) linear analytical ranges between 2.08 and 208 ppb, and (b) detection limits in the range from 0.01 to 0.92 ppb. The method was successfully applied to the determination of PAHs in river waters. 相似文献
73.
Goran M. Petrović Marija D. Ilić Vesna P. Stankov-Jovanović Gordana S. Stojanović Snežana Č. Jovanović 《Natural product research》2018,32(3):331-334
Phytochemical analysis by GC and GC/MS of the essential oil samples obtained from fresh shoots and flowers of Saponaria officinalis L. allowed the identification of 96 components in total, comprising 94.7% and 86.0% of the total oils compositions, respectively. Regarding the shoots essential oil, the major of 87 identified volatile compounds were phytol (14.1%), tricosane-6,8-dione (13.4%), patchouli alcohol (7.9%) and tricosane (7.2%), whereas patchouli alcohol (20.0%), heneicosane (11.5%) and tricosane (8.4%) were dominant among the 66 volatiles in the flower oil. Nonterpenoid compounds had the highest contribution in S. officinalis shoots essential oil (53.7%), while in the flower oil, constituents were almost evenly distributed between the oxygenated sesquiterpenoid (41.2%) and nonterpenoid compounds (39.5%). 相似文献
74.
The thermal and thermo-oxidative processes in Aroniamelanocarpa (black chokeberry) were investigated using combined thermo-analytical (TG-DTA) and spectroscopic (FTIR) experimental techniques. Isoconversional analysis revealed that the process in an inert (argon) atmosphere was probably governed by chlorogenic acid degradation, where autocatalysis (described by the empirical ?esták-Berggren model) might occur due to water already present in the early stages of the process through hydrolysis. Thermal degradation is described by the intrinsic kinetic parameters, where the degradation rate increases proportionally with an increase in the heating rate. Under oxidative conditions, the process was found to be primarily driven by neochlorogenic acid degradation. The thermo-oxidative degradation of Aroniamelanocarpa fresh samples can be described by two competitive reactions, where it was established that a cyanidin-3-glucosylrutinoside degradation made a significant contribution to a comprehensive kinetics. This study showed the targeting of the neochlorogenic acid in Aroniamelanocarpa fresh samples to have a strong hydrogen-donating activity, thereby rendering it capable of very efficiently entrapping the peroxy radicals. Current research has demonstrated that the relative contribution of the two competitive reactions to the overall process is highly dependent on the heating rate of the system under consideration. 相似文献
75.
Electrochemical behavior and antioxidant and prooxidant activity of natural phenolics 总被引:1,自引:0,他引:1
We have investigated the electrochemical oxidation of a number natural phenolics (salicylic acid, m-hydroxybenzoic acid, p-hydroxybenzoic acid, protocatechuic acid, o-coumaric acid, m-coumaric acid, p-coumaric acid, caffeic acid, quercetin and rutin) using cyclic voltammetry. The antioxidant properties of these compounds were also studied. A structural analysis of the tested phenolics suggests that multiple OH substitution and conjugation are important determinants of the free radical scavenging activity and electrochemical behavior. Compounds with low oxidation potentials (Epa lower than 0.45) showed antioxidant activity, whereas compounds with high Epa values (>0.45) act as prooxidants. 相似文献
76.
Marija Reni? 《Tetrahedron letters》2007,48(44):7873-7877
New adamantane-dipyrromethanes (AdD 1-4) were synthesized and their anion binding properties investigated. AdD 1-3 form 2:1 complexes with F− (AdD:F = 2:1) characterized by high association constants, and 1:1 complexes with Cl−, Br−, and . The binding of Cl−, Br−, and by AdD 1-3 is 2-3 times stronger than for the reference compound, meso-phenyldipyrromethane (5). However, AdD 4 forms complexes with F− characterized by 1:1 and 1:2 stoichiometry (AdD:F = 1:2). 相似文献
77.
eljka Fiket Marija Petrovi Gordana Meduni Tatjana Ivoevi Tomislav Fiket Lizzy Zhang Xu Yan Wang Shiming Ding 《Molecules (Basel, Switzerland)》2021,26(21)
Assessing the environmental quality of coastal systems is important not only for the management and protection of such areas, but also for improving the quality of water resources. Since sediment itself can often be a source of certain toxic elements, in addition to information on the distribution of metals in the water column and in the sediment itself, it is useful to determine the bioavailable forms of individual elements, particularly toxic ones. In this study, water and sediment geochemical data were supplemented with oxyanion mobility in sediments estimated by diffusion gradients in thin film (DGTs). The data obtained indicate that the chemical composition of the water in the Raša River estuary primarily reflects the high input of suspended sediment from the catchment, the mixing of freshwater and seawater, and to a lesser extent the effects of anthropogenic activities. Although sediment composition is primarily determined by geological and hydrodynamic conditions in the catchment, it also indicates moderate enrichment in Co, Cr, Mo and Ni. In contrast, the distribution of oxyanions in sediment pore water indicates the influence of sediment as a source of some elements in the bottom water; e.g., sediment contributes to 40% of the arsenic bottom water budget. The obtained depth profiles of the oxyanion distribution in the sediment pore water indicate an early onset of suboxic to anoxic conditions in Raša Bay, which is prone to rapid sedimentation. All this demonstrates the need to consider the bioavailable forms of elements when assessing environmental quality, as the lack of such information can lead to an incomplete assessment, especially in dynamic coastal systems such as estuaries. 相似文献
78.
Sergej Naumov Marija Bonifačić Richard S. Glass Klaus-Dieter Asmus 《Research on Chemical Intermediates》2009,35(4):479-496
A complementary quantum mechanical and experimental study has been undertaken on the reactivity, formation and properties
of Se∴N and S∴N σ2/σ* three-electron-bonded radical species, generated upon one-electron oxidation of selenomethionine, methionine and structurally
related compounds. The quantum chemical calculations were based on density functional theory (DFT) hybrid B3LYP and BHandHLYP
methods with basis sets ranging from 6-31G(d) to 6-311+G(d,p). Solvent effects, which play an important role concerning structure
and energy of ground and excited states, were taken into account as dielectric continuum as well as explicit water molecules.
They fully confirm new and previously obtained experimental results concerning the Vis/near-UV absorptions and thermodynamic
stability. Special emphasis was put on a comparison between selenium and sulfur. The calculations clearly confirm the higher
thermodynamic stability of the Se∴N radical species relative to the S∴N ones, and also corroborate the observed much higher
kinetic stability of the former. Concerning optical absorptions, the calculations predict the Se∴N transients to exhibit a
blue-shift by about 20 nm relative to the S-based analogues, confirming the few experimental data available so far. The theoretical
study includes a comparison of various calculation levels and the influence of the solvent environment, by comparison with
vacuum. New experimental data within the scope of this study have been obtained on intramolecularly-formed S∴N radical cation moieties, structurally stabilized by a rigid norbornane backbone. The methionine-related
species, with an endo-2-amino, exo-2-carboxyl, and endo-6 methylthio substitution, for example, exhibits almost identical
optical and kinetic stability properties as the corresponding species from free methionine. Its optical absorption depends
on the protonation state of the carboxyl group, with λmax at 410 nm for the carboxylate (zwitterionic) form and at 390 nm for the overall cationic form with the protonated carboxyl
group. The fast exponential decays with t
1/2 of 490 ns and 2 μs pertain to the decarboxylation of the respective species. A much longer-lived S∴N species with t
1/2 > 500 μs and second order decay kinetics (λmax 465 nm) was obtained from an endo-2-cyclohexylamino norbornane analogue which does not carry a carboxyl group. The methionine-based
S∴N species is not stable anymore in vacuum and in low polarity solvents. This is explained by a decrease in stabilization
energy of the 3-e-bond and a faster electron transfer from the carboxylate into the cationic 3-e-center. In conclusion, selenium
enhances the thermodynamic and kinetic stability of its radical transients, relative to the sulfur analogues. 相似文献
79.
Marija S. Nikolic Dr. Charlotta Olsson Andrea Salcher Andreas Kornowski Anja Rank Dr. Rolf Schubert Prof. Dr. Andreas Frömsdorf Dr. Horst Weller Prof. Dr. Stephan Förster Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(15):2752-2754
Nanoparticle brushes : Complex nanostructures can be formed by self assembly of amphiphilic CdSe/CdS core–shell nanoparticles that bear a brushlike layer of poly(ethylene oxide) chains. This route is based on controlling the volume fractions of hydrophilic and hydrophobic moieties within the particles and allows the formation of micellar, cylindrical, or vesicular nanoobjects (see picture).
80.