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41.
We study the Landau-Khalatnikov-Fradkin transformations (LKFT) in momentum space for the dynamically generated mass function
in QED3. Starting from the Landau gauge results in the rainbow approximation, we construct solutions in other covariant gauges.
We confirm that the chiral condensate is gauge invariant as the structure of the LKFT predicts. We also check that the gauge
dependence of the constituent fermion mass is considerably reduced as compared to the one obtained directly by solving SDE.
Correspondence: A. Bashir, Instituto de Física y Matemáticas, Universidad Michoacana de San Nicolás de Hidalgo, Apartado Postal
2-82, Morelia, Michoacán 58040, México 相似文献
42.
Jian Du Rui Sun Sheng Zhang Thirumala Govender Li‐Fang Zhang Cheng‐Dong Xiong Yu‐Xing Peng 《Macromolecular rapid communications》2004,25(9):954-958
Summary: Carboxymethyl Konjac Glucomannan–Chitosan (CKGM‐CS) nanoparticles, which are well dispersed and stable in aqueous solution, were spontaneously prepared under very mild conditions by polyelectrolyte complexation. Investigations of the physicochemical properties of these nanoparticles were undertaken. This study showed that the nanoparticulate system driven by complex formation has potential as an advanced drug‐delivery system for water‐soluble drugs.
43.
Dr. Khaoula Zinoubi Dr. Amani Chrouda Dr. Raya Soltane Prof. Dr. Youssef O. Al-Ghamdi Prof. Dr. Sami Garallah Almalki Prof. Dr. Gamal Osman Prof. Dr. Houcine Barhoumi Nicole Jaffrezic Renault 《Electroanalysis》2021,33(1):136-145
The fabrication of a thermolysin-based biosensor capable of detecting ochratoxin A (OTA) from food samples is described. The electrochemical deposition of calcium cross-linked cellulose film (CCLC) and gold nanoparticles (AuNPs) on graphene (GR) for modification of a glassy carbon electrode (GCE) is the first step. Then the thermolysin (TLN) enzyme in a polyvinyl alcohol (PVA)/polyethylenimine (PEI) matrix is immobilized. The impedimetric biosensor response is linear from 0.2 nM to 100 nM with a detection limit of 0.2 nM. The obtained stable and reproducible biosensor is then applied for the detection of OTA in spiked extracts from coffee beans. 相似文献
44.
Matteo Andrea Lucherelli Dr. Jésus Raya Konstantin F. Edelthalhammer Dr. Frank Hauke Prof. Andreas Hirsch Dr. Gonzalo Abellán Dr. Alberto Bianco 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(57):13218-13223
Graphene has been covalently functionalized through a one-pot reductive pathway using graphite intercalation compounds (GICs), in particular KC8, with three different orthogonally protected derivatives of 4-aminobenzylamine. This novel multifunctional platform exhibits excellent bulk functionalization homogeneity (Hbulk) and degree of addition while preserving the chemical functionalities of the organic addends through different protecting groups, namely: tert-butyloxycarbonyl (Boc), benzyloxycarbonyl (Cbz) and phthalimide (Pht). We have employed (temperature-dependent) statistical Raman spectroscopy (SRS), X-ray photoelectron spectroscopy (XPS), magic angle spinning solid state 13C NMR (MAS-NMR), and a characterization tool consisting of thermogravimetric analysis coupled with gas chromatography and mass spectrometry (TG-GC-MS) to unambiguously demonstrate the covalent binding and the chemical nature of the different molecular linkers. This work paves the way for the development of smart graphene-based materials of great interest in biomedicine or electronics, to name a few, and will serve as a guide in the design of new 2D multifunctional materials. 相似文献
45.
Haijun Peng Dr. Jésus Raya Dr. Fanny Richard Dr. Walid Baaziz Prof. Ovidiu Ersen Dr. Artur Ciesielski Prof. Paolo Samorì 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(44):19770-19777
Metal–organic frameworks (MOFs) and covalent organic frameworks (COFs) have attracted enormous attention in recent years. Recently, MOF@COF are emerging as hybrid architectures combining the unique features of the individual components to enable the generation of materials displaying novel physicochemical properties. Herein we report an unprecedented use of aza-Diels–Alder cycloaddition reaction as post-synthetic modification of MOF@COF-LZU1, to generate aza-MOFs@COFs hybrid porous materials with extended π-delocalization. A a proof-of-concept, the obtained aza-MOFs@COFs is used as electrode in supercapacitors displaying specific capacitance of 20.35 μF cm−2 and high volumetric energy density of 1.16 F cm−3. Our approach of post-synthetic modification of MOFs@COFs hybrids implement rational design for the synthesis of functional porous materials and expands the plethora of promising application of MOFs@COFs hybrid porous materials in energy storage applications. 相似文献
46.
47.
The mononuclear cationic complexes [(η6-C6H6)RuCl(L)]+ (1), [(η6-p-iPrC6H4Me)RuCl(L)]+ (2), [(η5-C5H5)Ru(PPh3)(L)]+ (3), [(η5-C5Me5)Ru(PPh3)(L)]+ (4), [(η5-C5Me5)RhCl(L)]+ (5), [(η5-C5Me5)IrCl(L)]+ (6) as well as the dinuclear dicationic complexes [{(η6-C6H6)RuCl}2(L)]2+ (7), [{(η6-p-iPrC6H4Me)RuCl}2(L)]2+ (8), [{(η5-C5H5)Ru(PPh3)}2(L)]2+ (9), [{(η5-C5Me5)Ru(PPh3)}2(L)]2+ (10), [{(η5-C5Me5)RhCl}2(L)]2+ (11) and [{(η5-C5Me5)IrCl}2(L)]2+ (12) have been synthesized from 4,4′-bis(2-pyridyl-4-thiazole) (L) and the corresponding complexes [(η6-C6H6)Ru(μ-Cl)Cl]2, [(η6-p-iPrC6H4Me)Ru(μ-Cl)Cl]2, [(η5-C5H5)Ru(PPh3)2Cl)], [(η5-C5Me5)Ru(PPh3)2Cl], [(η5-C5Me5)Rh(μ-Cl)Cl]2 and [(η5-C5Me5)Ir(μ-Cl)Cl]2, respectively. All complexes were isolated as hexafluorophosphate salts and characterized by IR, NMR, mass spectrometry and UV-vis spectroscopy. The X-ray crystal structure analyses of [3]PF6, [5]PF6, [8](PF6)2 and [12](PF6)2 reveal a typical piano-stool geometry around the metal centers with a five-membered metallo-cycle in which 4,4′-bis(2-pyridyl-4-thiazole) acts as a N,N′-chelating ligand. 相似文献
48.
Interaction Mechanisms between guaiacols and lignin: the conjugated double bond makes the difference
Barrera-García VD Chassagne D Paulin C Raya J Hirschinger J Voilley A Bellat JP Gougeon RD 《Langmuir : the ACS journal of surfaces and colloids》2011,27(3):1038-1043
Lignin is considered to be responsible for a selective sorption of phenolic compounds on wood. In order to investigate the mechanisms involved, two similar guaiacol compounds--only differing by the nature of the para side chain--were adsorbed on oak wood extracted lignin. Vapor sorption-desorption isotherms indicated that about 3.5 wt % of 4-vinylguaiacol is adsorbed near saturation whereas it is only 0.8% for 4-ethylguaiacol. For both compounds, the isotherms displayed a hysteresis though significantly greater for 4-vinylguaiacol. Analyses of the hydroxyl stretching region of FTIR spectra of the lignin/4-ethylguaiacol and lignin/4-vinylguaiacol complexes indicated that physisorption via hydrogen bonds occurs for both sorbates with lignin phenolic hydroxyl groups but which would be more condensed for the former than for the latter. According to NMR spectra, these phenolic hydroxyl groups correspond to non-etherified guaiacyl subunits. In contrast with other para substituents, the conjugated vinyl bond favors not only physisorption but also chemisorption as witnessed by the fact that upon desorption in the vapor phase, even after pumping under dynamic vacuum for several days, about 1 wt % of 4-vinylguaiacol remains adsorbed onto lignin. 相似文献
49.
Dr. Prabhpreet Singh Dr. Cécilia Ménard‐Moyon Dr. Alessia Battigelli Dr. Francesca Maria Toma Dr. Jesus Raya Dr. Jitendra Kumar Nagapradeep Nidamanuri Prof. Sandeep Verma Dr. Alberto Bianco 《化学:亚洲杂志》2013,8(7):1472-1481
Herein, we have developed a synthetic strategy for the covalent double functionalization of single‐walled carbon nanotubes (SWCNTs) with a combination of purine–pyrimidine and purine–purine nucleobase systems. The nucleobases were introduced on the sidewall of oxidized SWCNTs through 1,3‐dipolar cycloaddition and by amidation of the carboxylic acids located at the tips and defect sites of the nanotubes. The new nanohybrids were characterized by transmission electron microscopy, thermogravimetric analysis, FTIR and Raman spectroscopy, magic‐angle spinning NMR spectroscopy, and Kaiser test. The nucleobase/SWCNT conjugates can be envisaged for the modulation of the interactions with nucleic acids by means of base pairing, thereby opening new possibilities in the development of DNA/CNT nanobioconjugates. 相似文献
50.
Two-dimensional (2D) 59Co correlation spectroscopy (COSY)/double-quantum-filtered (DQF)COSY experiments are reported for three tetrahedral mixed-metal clusters HFeCo3(CO)11L with L = PPh3, P(OMe)3, and PCy3 (Cy = cyclohexyl) in which the L-substituted Co center is chemically different from the other two. The 2D 59Co COSY and DQFCOSY NMR spectra of these clusters in solution prove the existence of a scalar coupling constant between the 59Co nuclei. To determine this value for each cluster, 2D 59Co COSY and DQFCOSY NMR spectra have been simulated by numerical density-matrix calculations. The predicted spectra mimic well the features of the experimental spectra if a scalar coupling is introduced between the Co nuclei. It was initially observed that the scalar coupling constants between the Co nuclei obtained from the 2D COSY and DQFCOSY NMR spectra differed significantly. In contrast to the 2D COSY spectra, the diagonal and cross peaks are of comparable intensity in the 2D DQFCOSY spectra, which leads to a considerable increase in the accuracy of the determination of the scalar coupling constant. 相似文献