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41.
V. V. Simakov 《Russian Journal of Electrochemistry》2005,41(6):653-654
Current-voltage curves for sensor structures based on thin tin oxide films are examined in various gases. Conditions favoring symmetrical nonlinear curves in the voltage range −30 to 30 V are found.__________Translated from Elektrokhimiya, Vol. 41, No. 6, 2005, pp. 735–737.Original Russian Text Copyright © 2005 by Simakov.Published on the basis of a report delivered at the VII Meeting on Fundamental Problems in Solid-State Ionics (Chernogolovka-2004). 相似文献
42.
To simplify the assessment method of soy protein isolate(SPI) functionalities,the viscosity and functionalities of commercial SPI products were studied.Viscosity value(y) increases with increasing concentration(x) and exhibits a highly significant correlation with the exponential equation y = a·ebx.The b values of products are gradually enhanced from dispersion,emulsion and injected to gel type.Products with low b values(<0.2),and high dispersivity were dispersion-type.Products having high b values (>0.4) and gel springiness were gel-type.The other products with centered b value(0.2-0.4),high solubility and emulsifying capacity were emulsion-type. 相似文献
43.
44.
Elena Chekmeneva José Manuel Díaz‐Cruz Cristina Ariño Miquel Esteban 《Electroanalysis》2010,22(2):177-184
The complexation of the natural antioxidants α‐lipoic acid (ALA) and its reduced form dihydrolipoic acid (DHLA) with Hg2+ was investigated by a recently proposed differential pulse voltammetric (DPV) method using the rotating Au‐disk electrode. Complexation processes are proposed from the multivariate curve resolution by alternating least squares (MCR‐ALS) analysis of DPV titration data. Main complexes were both 1 : 1 Hg : ALA and Hg : DHLA, although the formation of 1 : 2 complexes can be also deduced. ALA and DHLA show different Hg2+‐binding patterns at different pH. Voltammetric findings are completed with the data obtained by electrospray ionization mass‐spectrometry (ESI‐MS), especially in negative mode. 相似文献
45.
Wen‐Zuo Li Jian‐Bo Cheng Qing‐ Zhong Li Bao‐An Gong Jia‐Zhong Sun 《International journal of quantum chemistry》2010,110(10):1857-1862
The HBeN? and HNBe? anions have been investigated for the first time using the CASSCF, CASPT2, and DFT/B3LYP methods with the contracted atomic natural orbital (ANO) and cc‐pVTZ basis sets. The geometries of all stationary points along the potential energy surfaces were optimized at the CASSCF/ANO and B3LYP/cc‐pVTZ levels. The ground and the first excited states of HBeN? are predicted to be X2Π and A2Σ+ states, respectively. It was predicted that the ground state of HNBe? is X2Σ+ state. The A2Π state of HNBe? has unique imaginary frequency. A bend local minimum M1 was found along the 12A″ potential energy surface and the A2Π state of HNBe? should be the transition state of the isomerization reactions for M1 ? M1. The CASPT2/ANO potential energy curves of isomerization reactions were calculated as a function of HBeN bond angle. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010 相似文献
46.
The multireference configuration interaction (MRCI) electronic energy calculations with different basis sets have been performed on the ground state (X1Σ) and three low-lying excited states (3Σ, 1Π and 3Π) of HgCd dimer. The obtained potential energy curves (PECs) are fit to analytical potential energy functions (APEFs) using the Murrell–Sorbie potential function. Spectroscopic constants are calculated using the APEFs. Based on the PECs, the vibrational levels of each state are predicted. Our equilibrium positions of the X1Σ state and 3Π state are in excellent agreement with the experimental reports. 相似文献
47.
G.P. Voga 《Thermochimica Acta》2007,452(2):140-148
Expert systems are proposed in order to analyze thermogravimetric profiles. The methodology showed to be an efficient tool as a complementary procedure for experimentalists in the area of themogravimetric analysis. Several simple and complex molecules were used to validate the developed methodology. The advantage of the actual approach can be attributed to its efficient error minimization for each weigh loss and global process. In addition, the proposed expert system presents a low computational demanding. The validation analysis using compounds such as salicylato (amine) Co (III) complexes, norfloxacin complexes of manganese (II) and cobalt (II), and calcium borate produced an average confidence interval of about 2%. 相似文献
48.
The acid-catalysed esterification of myristic acid with isopropanol was studied by using near-infrared spectroscopy (NIR) in combination with soft-modeling curve resolution (MCR) methodology with a view to establishing the effect of experimental variables on the reaction kinetics. The reaction was conducted at temperatures above the boiling point of the alcohol, with continuous addition of an isopropanol/water mixture to the reactor. Spectral and concentration profiles were determined by applying soft-modeling curve resolution methodology to a column-wise augmented data matrix containing the spectra for the pure components. MCR profiles were compared with reference values and found to depart from then by less than 3% as %RSE for concentrations and to exhibit correlation above 0.999 for spectra.The reaction kinetics as estimated from the concentration profiles was found to be pseudo-first-order. Also, the pseudo-first-order rate constant was found to depend on the flow-rate of the isopropanol/water mixture and its water content; although the constant decreased with increase in the proportion of water, a content of ca. 15% could be used without important retarding effects on the kinetics. The proposed NIR-MCR method allows the rate constant and the influence of the initial water content to be determined with a view to minimizing consumption of the raw materials and optimizing the experimental conditions. 相似文献
49.
Coleman MD Brewer PJ Smith IM Harris PM Clift MG Milton MJ 《Analytica chimica acta》2007,601(2):189-195
We report the use of a calibration transfer strategy to correct for drift in the quantitative sensitivity of a portable quadrupole mass spectrometer (QMS) aimed at process monitoring applications. Gas mixtures of CH4/Ar/C2H6/CO2 were studied with calibration phase measurements made of the pure gases for a univariate analysis and of 40 multi-component mixtures for a multivariate approach. To evaluate calibrations, test set spectra of a CH4/Ar/C2H6/CO2 gas mixture were recorded bi-weekly over a period of 12 months. As part of the strategy a standard of pure argon was measured during both calibration and test phases so that correction factors could be calculated for each measurement day. It was shown that in the absence of a calibration transfer strategy quantifications of test set spectra could be inaccurate by more than an order of magnitude over 12 months. Furthermore, due to the effects of drift in the sensitivity over the 6 days required to record the training set in the calibration phase it was found that the multivariate analysis quantified test spectra less accurately than the univariate analysis. However, by applying the calibration transfer strategy across all measurements (both calibration and test phases) it was shown that the errors in prediction using the multivariate analysis previously seen after 2 weeks were not observed until approximately 12 months later. 相似文献
50.
采用循环伏安与Tafel曲线比较不同阳极的电催化性能 总被引:1,自引:0,他引:1
采用循环伏安和Tafel曲线两种方法评价了Pt电极、钛基二氧化钌电极(Ti/RuO2)及钛基二氧化锡电极(Ti/SnO2)的电催化氧化性能.结果表明,在500 mg/L的苯酚溶液中,Pt,Ti/RuO2和Ti/SnO2电极氧化苯酚的峰电位依次为0.93,0.95和1.40 V(vsAg/AgCl).Tafel曲线表明,三种电极析氧过电位的顺序依次是Ti/RuO2相似文献