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301.
Application of artificial neural network for comparison and modeling of the ultrasonic and stirrer assisted removal of anionic dye using activated carbon supported with nanostructure material
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Abdol Mohammad Ghaedi Parisa Karami Mehrorang Ghaedi Azam Vafaei Ebrahim Alipanahpour Dil Fatemeh Mehrabi 《应用有机金属化学》2018,32(2)
In this study, a green approach has been described for the synthesis of copper sulfide nanoparticles loaded on activated carbon (CuS‐NP‐AC) and usability of it for the removal of sunset yellow (SY) dye by ultrasound‐assisted and stirrer has been compared. In addition, the artificial neural network (ANN) model has been employed for a forecasting removal percentage of SY dye using the results obtained. This material was characterized using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The impact of variables, including initial dye concentration (mg/L), pH, adsorbent dosage (g), sonication time (min) and temperature (°C) on SY removal was studied. Fitting the experimental equilibrium data of different isotherm models such as Langmuir, Freundlich, Temkin and Dubinin–Radushkevich models display the suitability and applicability of the Langmuir model. Analysis of experimental adsorption data of different kinetic models including pseudo‐first and second order, Elovich and intraparticle diffusion models indicate the applicability of the second‐order equation model. The adsorbent (0.005 g) is applicable for successful removal of SY dye (> 98%) in short time (9 min) under ultrasound condition. A three layer ANN models with 8 and 6 neurons at hidden layer was selected as optimal models using stirrer and ultrasonic, respectively. These models displayed a good agreement between forecasted data and experimental data with the determination coefficient (R2) of 0.9948 and 0.9907 and mean squared error (MSE) of 0.0001 and 0.0002 for training set using stirrer and ultrasonic, respectively. 相似文献
302.
MgBr2 supported on Fe3O4@SiO2 ~ urea nanoparticle: An efficient catalyst for ortho‐formylation of phenols and oxidation of benzylic alcohols
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Urea was successfully immobilized on the surface of chloropropyl‐modified Fe3O4@SiO2 core–shell magnetic nanoparticles, then supported by MgBr2 and acts as a unique catalyst for oxidation of benzylic alcohols to aldehydes and ketones, and ortho‐formylation of phenols to salicylaldehydes. The prepared catalyst was characterized by FT‐IR, transmission electron microscopy, scanning electron microscopy, X‐ray powder diffraction, dispersive X‐ray spectroscopy, CHN and TGA. It was found that Fe3O4@SiO2 ~ urea/MgBr2 showed higher catalytic activity than homogenous MgBr2, and could be reused several times without significant loss of activity. 相似文献
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305.
Mahmood Payehghadr Seyed Ebrahim Hashemi 《Journal of inclusion phenomena and macrocyclic chemistry》2017,88(3-4):253-257
The inclusion complexation of aromatic amines with cucurbit[6]uril (CB[6]) capped with alkali metal cations was studied spectrophotometrically. We showed that CB[6] capped with alkali metal cations forms a 1:1 inclusion complex with the aromatic amine guests (neutral organic molecules), independent of the length of guest molecules. The effects of salts on the inclusion constants of CB[6] in the presence of different alkali salts were examined and it was found that the inclusion constants increased in the order of alkali cation Cs+ < Na+ < K+, suggesting the interaction of amine guests with the capped alkali metal cation. Further, the structures of the inclusion complexation of aromatic amines with CB[6] were characterized by 1H NMR measurements. Based on the results, the inclusion abilities of CB[6] capped with alkali metal cations are discussed. 相似文献
306.
Ehsan Mehrabi Gohari Ebrahim Jahanshahi Javaran 《Journal of Dispersion Science and Technology》2017,38(10):1471-1482
Knowledge of an inverse fluidized-bed fluid hydrodynamics is advantageous in optimal adjustment and designing high-efficiency beds. In the present study, a combination of a single relaxation time collision operator lattice Boltzmann method (LBM) and the smoothed profile method (SPM) is employed to simulate the hydrodynamics of an inverse liquid–solid fluidized bed comprising circular monodisperse and polydisperse particles in a rectangular channel. A numerical instance of inverse fluidization involving 231 particles is illustrated to show the capability of the combined methods. Moreover, comparison of the numerical results is performed with the Ergun equation and the Richardson–Zaki correlation. The comparison demonstrates that the present model can simulate the fluid flow behavior in an inverse fluidized bed. Several different models were also presented to investigate the effect of different fluid properties and size of particles in the bed. Simulations indicate that the more the superficial liquid velocity, the higher the porosity of the bed. The present simulations show that porosity of the bed increases by increasing the particles size, and also the vertical velocity of the bed decreases with an increase in liquid viscosity. Finally, polydisperse particle systems are also simulated. The results show that porosity in an inverse fluidized bed comprising polydisperse particles is more than that of a monodisperse particle bed. 相似文献
307.
Synthesis of Pyranopyrazoles Using Magnetically Recyclable Heterogeneous Iron Oxide‐silica Core‐shell Nanocatalyst
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Ebrahim Soleimani Mohammad Jafarzadeh Parastoo Norouzi Jedol Dayou Coswald Stephen Sipaut Rachel Fran Mansa Parisa Saei 《中国化学会会志》2015,62(12):1155-1162
The Fe3O4@SiO2 core‐shell nanocatalyst were prepared and efficiently used for four‐component coupling reaction of aromatic aldehydes, malononitrile, ethyl acetoacetate and hydrazine hydrate in water/ethanol mixture. Various aromatic aldehydes possessing electron‐withdrawing and electron‐donating groups in different positions on the ring were successfully transformed to substituted pyranopyrazoles in high yields in short time. The nanocatalyst was easily recovered, and reused five times without significant loss in cata‐ lytic activity and performance. The structure, size and morphology of the nanosized catalyst were studied by various techniques such as Fourier transform infrared spectroscopy, powder X‐ray diffraction, dynamic light scattering and transmission electron microscopy. 相似文献
308.
Concentration and pattern changes of porcine serum apolipoprotein A‐I in four different infectious diseases
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Anna Marco‐Ramell Karin Hummel Ebrahim Razzazi‐Fazeli Anna Bassols Ingrid Miller 《Electrophoresis》2015,36(4):543-551
Apolipoprotein A‐I (Apo A‐I) is a major protein in lipid/lipoprotein metabolism and decreased serum levels have been observed in many species in response to inflammatory and infectious challenges. Little is known about the porcine homologue, therefore in this work we have characterized it through biochemical and proteomic techniques. In 2DE, porcine serum Apo A‐I is found as three spots, the two more acidic ones corresponding to the mature protein, the more basic spot to the protein precursor. Despite high sequence coverage in LC‐MS/MS, we did not find a sequence or PTM difference between the two mature protein species. Besides this biochemical characterization, we measured overall levels and relative species abundance of serum Apo A‐I in four different viral and bacterial porcine infectious diseases. Lower overall amounts of Apo A‐I were observed in Salmonella typhimurium and Escherichia coli infections. In the 2DE protein pattern, an increase of the protein precursor together with a lower level of mature protein species were detected in the porcine circovirus type 2‐systemic disease and S. typhimurium infection. These results reveal that both the porcine serum Apo A‐I concentration and the species pattern are influenced by the nature of the infectious disease. 相似文献
309.
Seyed Ebrahim Hashemi Mahmood Payehghadr Zarrin Es'haghi Hadi Kargar 《International journal of environmental analytical chemistry》2013,93(12):1148-1163
ABSTRACTIn this approach, a new carbon paste electrode modified with N,N′-bis(5-bromo-2-hydroxybenzylidene)-2,2-dimethylpropane-1,3-diamine Schiff base ligand (L) was synthesised for selective and effective determination of Hg2+ ions in aqueous environmental samples using cyclic and square wave anodic stripping voltammetric methods. First, the selective detection of mercury ion was confirmed by evaluating the stability constants of metal complexes formed between the Schiff base ligand (L) and some desired cations by conductometric measurements. Afterwards, by preparing an effective carbon paste electrode modified with L, the experimental and instrumental parameters affecting the performance of modified electrode were investigated. Square wave anodic stripping voltammograms were obtained after applying an accumulation potential ?0.5 V and accumulation time 150 s in Britton–Robinson buffer solution at pH 2.0. The optimal square wave parameters found are pulse amplitude 75 mV, frequency 50 Hz and step potential 6 mV. The procedure exhibited linear range from 0.4 to 120 μg L?1 Hg2+ with a limit of detection of 0.042 μg L?1. The proposed electrode was proved to be highly selective in the presence of various cations and anions and was successfully used for determination of mercury in tobacco and several water samples. 相似文献
310.
Ebrahim Kianmehr Katayoun Tabatabai Alireza Abbasi Hamideh Shokouhi Mehr 《合成通讯》2013,43(15):2529-2539
An efficient and straightforward pyridine-catalyzed method allowing selective O-vinylation of phenols with DMAD is reported. The reaction is diastereoselective and leads exclusively to (Z)-configuration in high yields. 相似文献