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51.
Manal M. Elshahawi Ahmed K. EL‐Ziaty Jehan M. Morsy Aly F. Aly 《Journal of heterocyclic chemistry》2016,53(5):1443-1448
A novel bis benzoxazin‐4‐one derivative has been synthesized and utilized to construct a new series of bis quinazolin‐4(3H)‐one derivatives via the reactions with different nitrogen nucleophiles namely, primary amines (ammonia, ethanolamine, and 4‐aminoantipyrine), secondary amines (morpholine and piperidine), diamine (o‐phenylenediamine), hydrazine hydrate, and hydroxylamine. The insecticidal efficacy of newly synthesized compounds was also studied. The structural features of the synthesized compounds were assigned by spectral analysis. 相似文献
52.
Muhammad Zahid Maria Lodhi Zulfiqar Ahmad Rehan Hamna Tayyab Talha Javed Rubab Shabbir Ahmed Mukhtar Ayman EL Sabagh Robert Adamski Mohamed I. Sakran Dorota Siuta 《Molecules (Basel, Switzerland)》2021,26(11)
The formation of new scaffolds to enhance healing magnitude is necessarily required in biomedical applications. Granulation tissue formation is a crucial stage of wound healing in which granulation tissue grows on the surface of a wound by the formation of connective tissue and blood vessels. In the present study, porous hydrogels were synthesized using chitosan incorporating latex of the Calotropis procera plant by using a freeze–thaw cycle to stimulate the formation of granulation tissue and angiogenesis in wound healing applications. Structural analysis through Fourier transform infrared (FTIR) spectroscopy confirmed the interaction between chitosan and Calotropis procera. Latex extract containing hydrogel showed slightly higher absorption than the control during water absorption analysis. Thermogravimetric analysis showed high thermal stability of the 60:40 combination of chitosan (CS) and Calotropis procera as compared to all other treatments and controls. A fabricated scaffold application on a chick chorioallantoic membrane (CAM) showed that all hydrogels containing latex extract resulted in a significant formation of blood vessels and regeneration of cells. Overall, the formation of connective tissues and blood capillaries and healing magnitude decreased in ascending order of concentration of extract. 相似文献
53.
B. EL Goundali M. Kaddami 《Fluid Phase Equilibria》2011,306(2):175-180
H2O + Ni(NO3)2 binary system were investigated in the temperature range from −25 °C to 55 °C. The solid-liquid equilibria of the ternary system H2O + Fe(NO3)3 + Ni(NO3)2 were studied using a synthetic method based on conductivity measurements. Tow isotherms were established at 0 °C and 30 °C, and the appearing stable solid phases are iron nitrate nonahydrate (Fe(NO3)3·9H2O), iron nitrate hexahydrate (Fe(NO3)3·6H2O), nickel nitrate hexahydrate (Ni(NO3)2·6H2O) and nickel nitrate tetrahydrate (Ni(NO3)2·4H2O). 相似文献
54.
Mn(II), Co(II), Ni(II), Cu(II), Pd(II) and Ru(III) complexes of Schiff bases derived from the condensation of sulfaguanidine with 2,4‐dihydroxy benzaldehyde ( HL1 ), 2‐hydroxy‐1‐naphthaldehyde ( HL2 ) and salicylaldehyde ( HL3 ) have been synthesized. The structures of the prepared metal complexes were proposed based on elemental analysis, molar conductance, thermal analysis (TGA, DSC and DTG), magnetic susceptibility measurements and spectroscopic techniques (IR, UV‐Vis, and ESR). In all complexes, the ligand bonds to the metal ion through the azomethine nitrogen and α‐hydroxy oxygen atoms. The structures of Pd(II) complex 8 and Ru(III) complex 9 were found to be polynuclear. Two kinds of stereochemical geometries; distorted tetrahedral and distorted square pyramidal, have been realized for the Cu(II) complexes based on the results of UV‐Vis, magnetic susceptibility and ESR spectra whereas octahedral geometry was predicted for Co(II), Mn(II) and Ru(III) complexes. Ni(II) complexes were predicted to be square planar and tetrahedral and Pd(II) complexes were found to be square planar. The antimicrobial activity of the ligands and their metal complexes was also investigated against the gram‐positive bacteria Staphylococcus aures and Bacillus subtilis and gram‐negative bacteria, Escherichia coli and Pesudomonas aeruginosa, by using the agar dilution method. Chloramphenicol was used as standard compound. The obtained data revealed that the metal complexes are more or less, active than the parent ligand and standard. The X‐ray crystal structure of HL3 has been also reported. 相似文献
55.
O. EL AKRAMINE W. A. LESTER JR X. KROKIDIS C. A. TAFT T. C. GUIMARAES A. C. PAVAO 《Molecular physics》2013,111(1-2):277-285
The chemisorption of CO on a Cr (110) surface is investigated using the quantum Monte Carlo method in the diffusion Monte Carlo (DMC) variant and a model Cr2CO cluster. The present results are consistent with the earlier ab initio HF study with this model that showed the tilted/near-parallel orientation as energetically favoured over the perpendicular arrangement. The DMC energy difference between the two orientations is larger (1.9 eV) than that computed in the previous study. The distribution and reorganization of electrons during CO adsorption on the model surface are analysed using the topological electron localization function method that yields electron populations, charge transfer and clear insight on the chemical bonding that occurs with CO adsorption and dissociation on the model surface. 相似文献
56.
40 absolute line wavenumbers in the 3v 3 band of 12C16O2 between 6927 cm?1 and 6989 cm?1 and 626 absolute line wavenumbers in the near infrared absorption spectrum of 12C2H2 between 7060 cm?1 and 9900 cm?1 have been measured using high resolution Fourier transform spectroscopy. The calibration of the CO2 line wavenumbers relied on heterodyne frequencies available in the v 1 + v 3 band of 12C2H2 near 6556 cm?1. The absolute uncertainty of the calibrated CO2 line wavenumbers is estimated to 0.000 08 cm?1. The acetylene spectra were calibrated using heterodyne frequencies available in the 2—0 band of 12C16O and the line wavenumbers obtained in the 3v 3 band of 12C16O2. The absolute uncertainty of the calibrated acetylene line wavenumbers is estimated to range from 0.0003 cm?1 to 0.006 cm?1 for strong to very weak isolated lines. Comparison with absolute line wavenumbers obtained independently at JPL in the 3v 3 band of 12C2H2 near 9649 cm?1, calibrated using absolute wavenumbers available in the 2—0 and 3—0 (near 6350 cm?1) bands of 12C16O, shows very good agreement. Also, the vibration—rotation constants for the observed upper vibrational states of 12C2H2 were determined, but without accounting for the perturbations affecting these states. 相似文献
57.
Khalil EL KHATABI Ilham AANOUZ Reda El-MERNISSI Atul Kumar SINGH Mohammed Aziz AJANA Tahar LAKHLIFI Shashank KUMAR Mohammed BOUACHRINE 《Turkish Journal of Chemistry》2021,45(3):647
Alzheimer’s disease (AD) is a multifactorial and polygenic disease. It is the most prevalent reason for dementia in the aging population. A dataset of twenty-six 1,2,3-triazole-based derivatives previously synthetized and evaluated for acetylcholinesterase inhibitory activity were subjected to the three-dimensional quantitative structure-activity relationship (3D-QSAR) study. Good predictability was achieved for comparative molecular field analysis (CoMFA) (Q2 = 0.604, R2 = 0.863, rext2 = 0.701) and comparative molecular similarity indices analysis (CoMSIA) (Q2 = 0.606, R2 = 0.854, rext2 = 0.647). The molecular features characteristics provided by the 3D-QSAR contour plots were quite useful for designing and improving the activity of acetylcholinesterase of this class. Based on these findings, a new series of 1,2,3-triazole based derivatives were designed, among which compound A1 with the highest predictive activity was subjected to detailed molecular docking and compared to the most active compound. The selected compounds were further subjected to 20 ns molecular dynamics (MD) simulations to study the comparative conformation dynamics of the protein after ligand binding, revealing promising results for the designed molecule. Therefore, this study could provide worthy guidance for further experimental analysis of highly effective acetylcholinesterase inhibitors. 相似文献
58.
Anowar Tozri Moez Bejar Essebti Dhahri EL Kébir Hlil 《Central European Journal of Physics》2009,7(1):89-95
X-ray powder diffraction (XRD) and magnetic measurements were performed in order to investigate the effect of Na+ ion substitution for Ca2+ ions on the crystallographic structure, the character of magnetic ordering, and the effect of transition temperature in La0.7Ca0.3−x
Na
x
MnO3 manganites series (0 ⩽ × ⩽ 0.2). All samples crystallise in an orthorhombic structure with the Pnma space group. We have found a strong dependence of structural and magnetic properties on the cation-size disorder parameter
σ
2. The temperature dependence of magnetization of all samples obeys the Bloch T
3/2 law. The values of the spin wave constant at low temperature B increase with the increase of x and the Curie temperature decreases. It is concluded that the substitution of Ca by Na+ ions causes a decrease in total exchange integral Aof the samples.
相似文献
59.
Monte Carlo simulation has been used to study the magnetic properties and hysteresis loops of a single nanocube, consisting of a ferromagnetic core of spin- surrounded by a ferromagnetic shell of spin-1 with antiferromagnetic interface coupling. We find a number of characteristic phenomena. In particular, the effects of the shell coupling and the interface coupling on both the compensation temperature and the magnetization profiles are investigated. The effects of the interface coupling on the hysteresis loops are also examined. 相似文献
60.
Using Monte Carlo simulations with the Metropolis algorithm, we have studied the influence of crystal-field interaction on the critical behavior of magnetic spin-1 Ising film on a cubic lattice structure. The phase diagrams in the (kBTc/J,R=Js/J) plane are obtained for different values of the crystal-field interaction. We found that the special point Rsp(Rc), at which the critical temperature is independent of the film thickness N, is independent of the crystal-field interaction and that the system may exhibit a tricritical behavior. 相似文献