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1.
2.
In the present study, to remove methylene blue (MB) from aqueous solution, some agricultural residues and cheap bioadsorbents such as sawdust of palm trees, eucalyptus, and sour lemon were used. To do this, significant parameters like contact time, temperature, pH, initial concentration, and adsorbent dosage were checked. The results affirmed that the best conditions for MB adsorption from aqueous solution were obtained such as the temperature of 25?°C, pH of 8, adsorbent dosage of 2g/L, contact time of 120?minutes, and dye concentration of 5?mg/l which under these conditions the adsorption efficiencies determined were 95.8, 93.4, and 92.8% using sawdust of palm tree, eucalyptus, and sour lemon, respectively. Also, the equilibrium behavior of adsorbents showed that the Freundlich model could better predict the adsorption behavior of the process due to having a larger correlation coefficient (R2). The maximum biosorption capacities by Langmuir isotherm model were also obtained 54, 53.5, and 52.4?mg/g for sawdust of palm trees, eucalyptus, and lemon, respectively, which were significant amounts. In addition, kinetic behavior of adsorption showed that pseudo-second-order model can describe the kinetics of the adsorption process better than the pseudo-first-order model. Moreover, kinetic, equilibrium, and thermodynamic behaviors of adsorption affirmed that the biosorption process was desirable, physisorption, spontaneous, and exothermic. 相似文献
3.
Reaction of tBuPLi2 with Carbodiimides The reaction of bis(cyclohexyl)carbodiimide with tBuPLi2 in THF at 20 °C leads to the tetranuclear Li‐complex [Li4(THF)2{tBuP([cHexN]2C)2}2] ( 1 ). No addition on the carbodiimide but a silyl transfer was observed under similar conditions during the treatment of bis(trimethylsilyl)carbodiimide with tBuPLi2 to give the lithium salts tBuP(SiMe3)Li and [Li(THF)(Me3SiN‐C≡N)]n ( 2 ). 1 was characterized by NMR, IR and RE spectroscopy, mass spectrometry and X‐ray analyses. Theoretical calculations were performed for 1 . According to the structural investigations 1 consists ofa central centrosymmetrical twelve‐membered Li2N4C4P2 ring adjacent by two six‐membered LiN2C2P rings. The peripheric Li+ cations posssess coordination number (cn) 3 buildt‐up by two N atoms and a THF ligand, while the two central Li+ cations possess only cn 2. However, the theoretical calculations have shown no relevant bonding Li···Li or Li···P interaction. 相似文献
4.
The complexation reactions between murexide and Co2+, Ni2+ and Cu2+ in C2H5OH-H2O mixtures have been investigated spectrophotometrically. The formation constants of the 1:1 complexes formed increase in the order Co2+ < Ni2+ < Cu2+ for all solvent mixtures studied, and log Kf is a linear function of the mole fraction of ethanol. The heat of complexation was determined calorimetrically for the nickel and copper complexes. The values of ΔH° and ΔS° are solvent-dependent, and all three complexes have negative ΔH° and positive ΔS° values. 相似文献
5.
The reaction of 2,6‐pyridinedicarboxylic acid ( 1 , LH2) with CeCl3·7H2O and Sm(NO3)3·6H2O in the presence of triethylamine led to the coordination polymer complexes [M(L)(LH)(H2O)2]·4H2O [M = Ce ( 2 ) and Sm ( 3 )]. Both complexes were characterized by elemental analyses, IR spectroscopy and the crystal structures of 2 and 3 . Crystal data for 2 at ?80 °C: monoclinic, space group P21/c, a = 1404.6(1), b = 1122.1(1), c = 1296.1(1) pm, β = 102.09(1)°, Z = 4, R1 = 0.0217 and for 3 at ?80 °C: monoclinic, space group P21/c, a = 1395.1(1), b = 1120.1(1), c = 1282.8(1) pm, β = 102.71(1)°, Z = 4, R1 = 0.019. 相似文献
6.
Heidar Raissi Effat Moshfeghi Abraham F. Jalbout Mohammad Saeid Hosseini Mustapha Fazli 《International journal of quantum chemistry》2007,107(9):1835-1845
The molecular structure and intramolecular hydrogen bond energy of 32 conformers of 4‐methylamino‐3‐penten‐2‐one were investigated at MP2 and B3LYP levels of theory using the standard 6–31G** basis set and AIM analyses. Furthermore, calculations for all the possible conformations of 4‐methylamino‐3‐penten‐2‐one in water solution were also carried out at B3LYP/6–31G** level of theory. The calculated geometrical parameters and conformational analyses in gas phase and water solution show that the ketoamine conformers of this compound are more stable than the other conformers (i.e., enolimine and ketoimine). This stability is mainly due to the formation of a strong N? H···O intramolecular hydrogen bond, which is assisted by π‐electrons resonance. Hydrogen bond energies for all conformers of 4‐methylamino‐3‐penten‐2‐one were obtained from the related rotamers method. The nature of intramolecular hydrogen bond existing within 4‐methylamino‐3‐penten‐2‐one has been investigated by means of the Bader theory of atoms in molecules, which is based on topological properties of the electron density. The results of these calculations support the results which obtained by related rotamers method. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007 相似文献
7.
Tayyebeh Madrakian Akram Esmaeili Azizeh Abdolmaleki 《Journal of Analytical Chemistry》2004,59(1):28-32
A new method for the rapid and sensitive determination of trace quantities of thiocyanate based on its Landolt effect on the bromate-hydrochloric acid reaction was developed. The induction period of the reaction is proportional to the SCN– concentration. The decolorization of methyl orange by the reaction products was used to monitor the reaction spectrophotometrically at 525 nm. We were able to determine thiocyanate in the range 2 × 10–7–4 × 10–5 M by this method. The relative standard deviation for 10 determinations of 1.5 × 10–6 M thiocyanate ion is 0.19% and the detection limit of the method was 7.00 × 10–8 M. The method was applied to the determination of thiocyanate in human blood serum and of saliva samples with satisfactory results. 相似文献
8.
Diorganomorpholinometalates of Gallium and Indium – Monomer‐Dimer‐Equilibrium in Solution The reaction of Li[N(CH2CH2)2O] (LiMorpholinate; Li(Morph)) with Me2GaCl and Me2InCl gives by salt‐elimination the diorganoamidometalates Me2M(Morph) ( M = Ga: 1 ; M = In: 2 ), respectively. 1 and 2 were characterized by NMR and vibrational spectroscopy as well as by X‐ray structure determinations. According to this, centrosymmetrical dimers are present in the solid state while a monomer‐dimer equilibrium was assumed for the THF‐solution. Cryoscopic molecular weight determinations confirmed our assumptions. 相似文献
9.
Majid M. Heravi Mohammad Rahimizadeh Effat Iravani Mitra Ghassemzadeh 《Phosphorus, sulfur, and silicon and the related elements》2013,188(4):797-802
The synthesis of bicyclic compounds derived from benzo[1,2,4]triazines is described. 相似文献
10.
This article aims to provide a survey of biological applications of Schiff base macrocycles and their metal complexes, with emphasis given to the synthesis of the compounds and to their uses as antibacterial and antifungal agents. The literature on the subject, published during the 2005–2019 period, is shortly reviewed. This is an informed report collecting information on the addressed topic in a concise systematic way, and can be expected to be useful as a fast literature catalogue for researchers working on this and related domains. 相似文献