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991.
连续小波变换-独立成分回归算法及其在多组分分析中的应用 总被引:1,自引:0,他引:1
采用连续小波变换(CWT)对光谱数据进行处理,用独立成分分析(ICA)进行特征提取,再用回归分析方法对被测组分进行测定,建立了连续小波变换一独立成分回归(CWT-ICR)方法。方法用于肉样品中水分、脂肪和蛋白质多组分的同时测定,所得结果与化学法测得结果相符。 相似文献
992.
用化学键参数-模式识别或人工神经网络方法研究MeX-REX_3型熔盐相图,总结中间化合物的形成、化学配比和Me_3REX_6型化合物同分或异分熔化规律,并对其熔点或分解点进行预报. 相似文献
993.
Six novel pyrromethene BF2 complexes,of which five compounds have not been reported,were synthesized and characterized.Their relationships between st ructure and photophysical behavior were studied with the aid of fluorescence and triplet state absorption spectra.The results indicate that,compared to 8 alkyl pyrromethene BF2 complexes,the compounds containing 8 aryl exhibit high fluore scence quantum yield and rather low triplet state absorption. 相似文献
994.
995.
996.
A COMPARISON OF DENATURATION AND INACTIVATION RATES OF CREATINE KINASE IN GUANIDINE SOLUTIONS 总被引:1,自引:0,他引:1
Both the denaturation, as followed by UV absorbance and fluorescence changes, and inac-tivation of creatine kinase in guanidine solutions have been found to be first order reactions.In 3 M guanidine, at 30℃, the inactivation rate constant was found to be 5.9 sec~(-1) and thedenaturation rate constant 1.9 sec~(-1). At lower guanidine concentrations, the inactivation rateconstants were only little affected whereas the denaturation rate constants decreased markedly,being of the order of 0.04 in 1 M and 0.004 in 0.5 M guanidine. The kinetics of the inactiva-tion reaction in 0.5 M guanidine was found to be in agreement with a combination of two firstorder reactions. The enzyme lost activity first by a fast reaction with a rate constant onlyslightly lower than the rate constant in 3 M guanidine followed by a slower reaction with a rateconstant of 0.003 sec~(-1). In 0.3 M guanidine, very little change in either UV absorbance or influorescence was observed, but, in sharp contrast, the enzyme lost considerable activity by a fastreaction and this was followed by a slower reaction of inactivation. Even after prolongeddenaturation in 0.5 and 0.3 M guanidine, residual activities of 3.4% and 30% remained res-pectively. The above results suggest a very fragile active site although dissociation of thedimer and reversible guanidine inhibition may also contribute to the initial rapid inactiva-tion. It is also to be noted that the multiphasic courses of inactivation at lower guanidineconcentrations seem to suggest the presence of partly active intermediates during denaturation. 相似文献
997.
998.
The title complex 1·THF has been synthesized by the reaction of [HO-4,6-di-tBu- C6H2-2-CH2{CH(iPrNCHCHN)}]Cl with NdCl3 in a 2:1 molar ratio in THF, and characterized by single-crystal X-ray diffraction. It crystallizes in monoclinic, space group P21/c with a = 9.6501(14), b = 16.393(2), c = 36.745(6) , β = 97.444(4)o, V = 5763.7(15) 3, Mr = 1124.69, Z = 4, Dc = 1.296 g/cm3, μ(MoKα) = 1.175 mm-1, F(000) = 2348, the final R = 0.0729 and wR = 0.1762 for 8735 observed reflections with I > 2σ(I). Complex 1 consists of an anion [NdCl5(THF)]2- and two cations [HO-4,6-di-tBu-C6H2-2-CH2{CH(iPrNCHCHN)}]2 to form a layer structure by the interconnection of anions and cations via hydrogen bonding. The central metal Nd in the anionic unit is coordinated by five Cl atoms and one oxygen atom from solvated THF molecule assuming a distorted octahedral geometry. 相似文献
999.
SURFACE OF GELATIN MODIFIED POLY(L-LACTIC ACID)FILM 总被引:1,自引:0,他引:1
In this paper, the surface structure of poly(L-lactic acid) (PLLA) film modified with gelatin was investigated. ThePLLA film specimens were treated directly with aqueous alkali solution to provide their surfaces with carboxyl groups, sothat these functional groups could become the reactive sites for gelatin immobilization. The functional groups of the PLLAfilms were identified by ATR-FTIR spectra and XPS spectra, the changes in surface morphology were observed by usingenvironmental scanning electron microscopy (ESEM), and the hydrophilicity of modified PLLA films was examined bywater contact angle measurement. Experimental results showed that the gelatin was immobilized with water-solublecarbodiimide (EDC) onto the PLLA film's surfaces, and the gelatin content on the polymer surface was related to carboxylicgroup formed in the controlled hydrolysis process. Rough surfaces caused by hydrolysis will predominantly favor the adhesion and growth of cell; and the hydrophilicity of these surfaces after the modification procedure is enhanced. 相似文献
1000.