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91.
Maghsoodlou Malek Taher Habibi-Khorassani Sayyed Mostafa Heydari Reza Hazeri Nourollah Sajadikhah Seyed Sajad Rostamizadeh Mohsen 《中国化学》2010,28(2):285-288
Synthesis of α‐amino phosphonates is described under solvent‐free conditions at 100°C from reaction between aldehydes and amines in the presence of trialkyl phosphites using Al(H2PO4)3 as an efficient and reusable heterogeneous catalyst. The advantages of this procedure are short reaction time, flexibility and having high to excellent yields. 相似文献
92.
Malek Taher Maghsoodlou Sayyed Mostafa Habibi-Khorassani Zahra Shahkarami Nariman Maleki Mohsen Rostamizadeh 《中国化学快报》2010,21(6):686-689
<正>2,2'-Arylmethylene bis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) 4l-s produced from reaction between dimedone with various aldehydes in acetonitrile using ZnO as a catalyst;whereas in the presence of ZnO-acetyl chloride catalysts the reaction is limited to give only 1,8-dioxo-octahydroxanthenes 3a-k in very good yields. 相似文献
93.
Firouz Matloubi Moghaddam Mostafa Kiamehr Salman Taheri Zohreh Mirjafary 《Helvetica chimica acta》2010,93(5):964-973
An efficient synthesis of polycyclic indole derivatives is achieved via domino Knoevenagel–hetero‐Diels–Alder reaction of O‐acrylated salicylaldehyde derivatives with dihydroindole‐2‐thiones in H2O as solvent. The products are formed in good‐to‐excellent yields with high regio‐ and stereoselectivity. 相似文献
94.
Firouz Matloubi Moghaddam Mostafa Kiamehr 《Monatshefte für Chemie / Chemical Monthly》2010,41(5):1333-1337
Abstract
The site-selectivity and regioselectivity of Diels–Alder reactions of allenyl aryl ethers with cyclopentadiene and acrolein were studied. While cyclopentadiene (as an electron-rich diene) only reacted with the external double bond of allenyl aryl ethers to provide the site-selective normal electron demand Diels–Alder cycloadducts, acrolein (as an electron-deficient diene) reacted with the C1–C2 π bond of allenyl aryl ethers to provide the site- and regioselective hetero-Diels–Alder cycloadducts as exclusive products. 相似文献95.
The spectroscopic and kinetic studies of the interaction between bacteriorhodopsin in the M-intermediate and several surfactants (cetyl trimethyl ammonium bromide, dodecyl trimethyl ammonium bromide, diethylene glycol mono-n-hexyl ether, ethylene glycol mono-n-hexyl ether, sodium 1-decanesulfonate and sodium 1-heptanesulfonate) have been investigated using steady-state UV–VIS spectrometry and time-resolved absorption techniques. The steady-state spectral results show that bR retains its trimeric state. Time-resolved observations indicate that the rate of deprotonation of the protonated Schiff base increases in the presence of the cationic surfactants, whereas insignificant changes are observed in the neutral or anionic surfactants. The rate of the reprotonation of the Schiff base in the transition M → N is accelerated in anionic and neutral surfactants, but is decelerated in the presence of the cationic surfactants. Surfactants with a longer hydrocarbon tail have a greater effect on the kinetics when compared with surfactants having shorter hydrocarbon tails. The opposite effect is observed when the hydrophilic head of the surfactants contains opposite charges. These distinct kinetics are discussed in terms of the difference in the modified surface hydrophilicity of the bR and the possible protein configurational changes upon surfactant treatments. 相似文献
96.
Fariborz Momenbeik Mostafa Roosta Ali Akbar Nikoukar 《Journal of chromatography. A》2010,1217(24):3770-3773
An environmentally benign and simple method has been proposed for separation and determination of fat-soluble vitamins using isocratic microemulsion liquid chromatography. Optimization of parameters affecting the separation selectivity and efficiency including surfactant concentration, percent of cosurfactant (1-butanol), and percent of organic oily solvent (diethyl ether), temperature and pH were performed simultaneously using genetic algorithm method. A new software package, MLR-GA, was developed for this purpose. The results indicated that 73.6 mM sodium dodecyl sulfate, 13.64% (v/v) 1-butanol, 0.48% (v/v) diethyl ether, column temperature of 32.5 °C and 0.02 M phosphate buffer of pH 6.99 are the best conditions for separation of fat-soluble vitamins. At the optimized conditions, the calibration plots for the vitamins were obtained and detection limits (1.06–3.69 μg mL−1), accuracy (recoveries > 94.3), precision (RSD < 3.96) and linearity (0.01–10 mg mL−1) were estimated. Finally, the amount of vitamins in multivitamin syrup and a sample of fish oil capsule were determined. The results showed a good agreement with those reported by manufactures. 相似文献
97.
Seyyed Hossein Asadpour Mostafa Sahrai Rasoul Sadighi-Bonabi Amir Soltani Hamed Mahrami 《Physica E: Low-dimensional Systems and Nanostructures》2011,43(10):1759-1762
The giant Kerr nonlinearity with reduced linear and nonlinear absorption in a four-level quantum dot by employing the tunnel coupling is investigated. It is shown that by enhancement of tunnel coupling value the Kerr nonlinearity increases and at the same time linear and nonlinear absorption reduces at the long wavelength which is very important for communicational applications. Enhanced of Kerr nonlinearity in a double quantum dots is investigated. It is found that the electron tunneling has an essential role to reducing the linear absorption and increasing the Kerr nonlinearity at long wavelength. 相似文献
98.
Malek Taher Maghsoodlou Ghasem Marandi Nourallah Hazeri Sayyed Mostafa Habibi-Khorassani Ali Akbar Mirzaei 《Molecular diversity》2011,15(1):227-231
5-Aryl-6-(alkyl- or aryl-amino)-1,3-dimethylfuro [2,3-d]pyrimidine derivatives were obtained by in situ reaction alkyl or aryl isocyanides and pyridinecarbaldehyde derivatives in
the presence of 1,3-dimethylbarbituric acid in dichloromethane without any prior activation or modifications. 相似文献
99.
The major objective of this work was the development of a reliable model to describe volumetric properties of ionic liquids
(ILs). In this regard, we have applied the Ihm–Song–Mason equation of state (EOS) to some phosphonium- and imidazolium-based
ILs. Three temperature-dependent parameters in the equation of state have been scaled based on the surface tension and the
liquid density at room temperature. In order to improve the predictive power of the mentioned EOS for ILs, we have proposed
using a simple modification. We have taken 1,228 experimental points to show the reliability of the improved EOS. The comparison
of predicted densities with literature data over a broad range of temperature, 293–472 K, and pressures up to 200 MPa led
to encouraging results. The average absolute deviation of calculated densities from literature values was found to be 0.75%. 相似文献
100.