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111.
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113.
十二水合硫酸铁铵催化合成己二酸二乙酯的研究 总被引:16,自引:0,他引:16
以十二水合硫酸铁胺为催化剂合成了己二酸二乙酯,确定了酯化优化条件。实验结果表明,催化剂的催化活性高,反应条件温和,方法简便,酯化率优良。 相似文献
114.
Jing Li Xufeng Ni Jun Ling Zhiquan Shen 《Journal of polymer science. Part A, Polymer chemistry》2013,51(11):2409-2415
Polymerization of diethyl vinylphosphonate (DEVP) is achieved by using lanthanide tris(borohydride) complexes, Ln(BH4)3(THF)3 (Ln = Y, La, Nd, Sm, Gd, Dy, Lu) as an initiator. The characteristics and mechanism of polymerization as well as the properties of the resulting poly(diethyl vinylphophonate)s (PDEVPs) are studied. The effects of the lanthanide elements, the molar ratios of monomer to initiator ([M]/[ln]), reaction temperature and time on polymerization have been investigated in detail. The optimized polymerization conditions are 40 °C, 1 h in bulk with [M]/[ln] = 300. The kinetic study indicates that the polymerization of DEVP undergoes a controlled manner as the molecular weights (MWs) of PDEVPs increase with monomer conversion linearly maintaining moderate MW distribution (1.7–1.9). Additionally, a coordination anionic polymerization mechanism is proved by end‐group analysis with ESI mass and 1H NMR spectroscopy. The obtained PDEVPs have low glass transition temperature (Tg = ?62 °C) and high thermal decomposition temperature (Td > 300 °C) determined by differential scanning calorimetry and thermogravimetric analysis respectively. The thermosensitive behavior of PDEVP is characterized by evaluating the lower critical solution temperature of PDEVP in water by ultraviolet transmittance. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2409–2415 相似文献
115.
The benzofuran skeleton is commonly found in a wide variety of natural products that display a wide range of biological activities. For this reason, benzofuran has a high potential for use as a scaffold in both chemical and pharmaceutical syntheses of natural products. This work describes the development of a novel asymmetric synthetic method of benzofuran-derived β-amino esters via K2CO3-promoted domino reactions of ortho-hydroxyl aromatic N-tert-butylsulfinyl imines and diethyl bromomalonate. A small library of target compounds was prepared under optimized reaction conditions in moderate to good yields with high distereoselective and enantioselective properties. The newly generated chiral carbon center was of an (S)-configuration as determined by x-ray diffraction. 相似文献
116.
Richard J. Petroski 《合成通讯》2013,43(21):3841-3854
New phosphonate reagents were developed for the two‐carbon homologation of aldehydes to unbranched or methyl‐branched unsaturated aldehydes. The phosphonate reagents, diethyl methylformylphosphonate dimethylhydrazone and diethyl ethylformyl‐2‐phosphonate dimethylhydrazone, contained a protected aldehyde group instead of the usual ester group. A homologation cycle entailed condensation of the reagent with the starting aldehyde, followed by removal of the dimethylhydrazone protective group with a biphasic mixture of 1 M HCl and petroleum ether. This robust two‐step process worked with aliphatic, α,β‐unsaturated and aromatic aldehydes. Isolated yields for the condensation step ranged from 77% to 89%, and yields for the deprotection step ranged from 81% to 96%. 相似文献
117.
Nadia Hanafy Metwally 《合成通讯》2013,43(23):4227-4237
Ethyl cyanoacetate dimer (1) undergoes bromination with N‐bromosuccinimide (NBS) to afford 3‐amino‐4‐bromo‐2‐cyano‐pent‐2‐enedioic acid diethyl ester (2). This bromo derivative reacts with potassium carbonate, sodium hydrogen sulfide, aromatic amines, ammonium thiocyanate, thiourea, N‐phenylthiourea, and thiosemicarbazide to afford highly substituted furan, thiophene, pyrrole, and 2‐aminothiazole derivatives. Mechanistic explanations as well as structure elucidations are discussed. 相似文献
118.
Mavallur Varalakshmi Chamarthi Nagaraju Palaa Krishna 《Phosphorus, sulfur, and silicon and the related elements》2013,188(12):853-857
AbstractA series of new class of diethyl N-2-hydroxyethyl-N'-substituted phosphoramidimidates 6(a–e) and diethyl P-morpholino-N-substituted phosphonimidates 6(f–j) was synthesized. The precursor intermediates, diethyl substituted phosphoramidites 3(a–b) were prepared initially by a reaction of various amines 1(a–b) and diethyl phosphorochloridite (2) and then they were treated by in situ with aromatic/alkyl azides through Staudinger reaction to accomplish title products. Structures of all the synthesized compounds were characterized by spectroscopic data such as IR, NMR (1H, 13C, 31P), mass, and elemental analyses. The synthesized compounds were screened for their in vitro antimicrobial activity to understand their biological potency. The biological screening results disclosed that compounds 6b, 6c, 6e, 6g, 6h and 6j having potent antimicrobial activity against all the tested pathogens. 相似文献
119.
Tadeusz Gajda 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4):327-331
Abstract Diethyl 1-bromoalkylphosphonates 1 have been obtained in good to moderate yields by the reaction of diethyl I-hydroxyalkylphosphonates 2 with the triphenylphosphine-carbon tetrabromide system or dibromotriphenylphosphorane. 相似文献
120.
《Green Chemistry Letters and Reviews》2013,6(1):53-59
Abstract An environmentally more convenient reaction for the production of industrially important aryl ethyl ethers (ArOEts) is described. ArOEts were selectively obtained in essentially quantitative yields by the reaction of corresponding (hetero)aromatic alcohols (ArOHs) with diethyl carbonate as the environmentally friendly alkylating reagent in the presence of N,N-dimethylacetamide used as polar aprotic cosolvent, and sodium ethoxide as the base. The reactions were carried out in the air under atmospheric pressure at 137°C. Reaction equilibrium was shifted by distilling the ethanol from the reaction mixture. All ArOEts were isolated by evaporation of the reaction mixture, and subsequent extraction with water and diethoxymethane. The ethylation agent and used solvents were non-toxic, recyclable and biologically degradable. Wastewater from the extraction was successfully treated by Fenton oxidation and returned to the next work-up process. 相似文献