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101.
Robert Łysek Ewa Woźny Marek Chmielewski 《Phosphorus, sulfur, and silicon and the related elements》2013,188(2):327-340
Chiral formates derived from propane-1,2-diol, 1,2- O -isopropylidene- f - D -xylo- and f - D -gluco-furanoses were subjected to treatment with cyclopentadienyl [tris(trimethylsilylmethyl)] titanium (IV). A mixture of the corresponding ( E )- and ( Z )- g -silylvinyl ethers were obtained with predominance of the former. It was found that in contrast to ( Z )-vinyl ethers, which give g -lactams with chlorosulfonyl isocyanate, the ( E )-vinyl ethers gave unstable cycloadducts which undergo rapid elimination reaction leading to ( E )- f , g -unsaturated amides. 相似文献
102.
Józef Drabowicz Piotr Łyżwa Jan Omelańczuk Marian Mikołajczyk 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1)
Abstract The title compound optically active t-butylphenylphosphine oxide 1 is widely used as a key substrat for the synthesis of other optically active derivatives such as α-hydroxyphosphine oxides, vinylphosphine oxides Till now, it has been obtained by a few rather laborious procedures1 相似文献
103.
Wladyslaw Reimschüssel Halina Abramczyk Jacek Michalak 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3-4):201-211
Abstract 2-Chloro-5,5-dimethyl-2-oxo-1,3,2-dioxaphosphorinane has been studied in CCl4, CHCl3 and CD3CN solutions by IR and Raman line shape analysis. Equilibrium process of dimerization and ring conversion in CCl4 solutions have been considered. On the contrary to the commonly expected dominance of the conformer with the equatorial oriented P[dbnd]O bond for 2-halo-2-oxo-1,3,2-dioxaphosphorinanes, it was found that for the 2-chloro derivative both conformers are nearly equally distributed. It has been shown that the interactions induced absorption is an important mechanism of relaxation in the studied compound and this mechanism gives significant contribution to the total IR band broadening, while the interaction induced light scattering is negligible. The obtained results show that the molecular dynamics method can be useful in studying cyclic compounds in solutions. 相似文献
104.
Bogumił Łaszkiewicz 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(2):421-432
The reaction mechanism of phosphorous acid and poly(vinyl alcohol) is presented. It has been found that there during this reaction mono- and diesters are formed in which most of the acid radicals are in the phosphonic form. To confirm the presence of this form in the product obtained, reactions with diethyleneamine and chloral have been carried out as characteristic tests for phosphonic groups. The occurrence of C—P bonds resistant to hydrolysis has been also found in the reaction product. 相似文献
105.
D. F. Parra P. L. Forster R. Łyszczek A. Ostasz A. B. Lugao Z. Rzączyńska 《Journal of Thermal Analysis and Calorimetry》2013,114(3):1049-1056
The aim of this study has been to gain a fundamental understanding of the mechanisms governing thermal degradation of luminescent poly(3-hydroxybutyrate) (PHB). PHB was doped with diaquatris(thenoyltrifluoroacetonate) europium(III) complex, [Eu(tta)3(H2O)2], and different luminescent systems were obtained. The thermal-stability of the luminescent films was discussed and the products of decomposition were analyzed. Thermal degradation of PHB:Eu(tta)3 x % systems (x = 0, 1, 5, 10, and 15 %) was elucidated by means of thermogravimetric analysis (TG), the thermal-stability decreases with the increase of europium complex concentration. The PHB polymer decomposed with evolution of carbon dioxide and 2-butenoic acid molecules. The TG–FTIR results, of the gaseous degradation products of PHB in nitrogen atmosphere, indicated that the polymer is stable at temperatures up to 200 °C. Polymer matrix at concentrations above 5 % decomposed with evolution of water molecules among the other gaseous products, which implied the presence of a hydrated complex in the system. The luminescent films showed more flexibility due to a loss in crystallinity, which suggested a potential usefulness in technical applications. 相似文献
106.
Jacek E. Nycz 《Phosphorus, sulfur, and silicon and the related elements》2013,188(10):2605-2612
The present study shows new aspects of the synthesis of polyhalogenoarylphosphanes. The sterically hindered anions Ph(R)P-Y? (1a–c, Y = O, lone pair; R = Ph, But) have been used to show the complexity of the reaction between phosphorus nucleophiles and hexahalogenobenzenes or 9-bromofluorene (E3). The Ph(But)P-O? (1a) anion reacts with hexachlorobenzene (E1), hexafluorobenzene (E2), or E3 to give Ph(R)P(O)X (4a–c, X = F, Cl, Br) with the release of the corresponding carbanion as a nucleofuge, followed by side reactions. In contrast, the lithium phosphides Ph(R)PLi (1b,c) react with hexahalogenobenzenes to give the corresponding diphosphanes 5a,b as the main product and traces of P-arylated products, i.e., Ph(R)P-C6X5 (10a,b, X = Cl, F). Unexpectedly, Ph(But)PLi (1b) reacts with an excess of 9-bromofluorene to give only halogenophosphane Ph(But)P-X. 相似文献
107.
Annia H. Kycia Kallum Koczkur J. Jay Leitch Jacek Lipkowski Vlad Zamlynny Michael W. P. Petryk 《Analytical and bioanalytical chemistry》2013,405(5):1537-1546
Polarization modulation–infrared reflection absorption spectroscopy (PM-IRRAS) was employed to analyze two unique samples: (1) an industrially prepared alkoxysilane-pretreated aluminum alloy (AA6111) in the absence and presence of a ~600-nm-thick lubricant coating and (2) a chemical warfare agent simulant, triethyl phosphate (TEP), on glass. For the pretreated aluminum samples, PM-IRRAS spectra were analyzed for three distinct regions; the SiO stretching vibration around 1120 cm?1, the NH2 bending mode at ~1600 cm?1 and the CH stretching region around 2900 cm?1. Our results showed that increasing the curing temperature (from 55 to 100 °C) improved the overall extent of cross-linking within the siloxane network. In addition, the spectra of lubricant (top coating) and the underlying siloxane layer for the aluminum samples with lubricant were collected for the same sample. Our results show that the nature of the siloxane film remains intact and unaltered after deposition of the lubricant top-coat. For detection of TEP on glass, the band at 1268 cm?1, corresponding to the P═O vibration, was monitored. A droplet of TEP solution in dichloromethane was deposited on glass. After solvent evaporation had occurred, the intensity of the P═O vibration band was used to construct calibration curves to determine the experimental limit of detection, which was found to be ~200 μg for TEP on glass. Figure
Schematic of a akoxysilane network and PM-IRRAS spectrum of the alkoxysilane film at aluminum surface 相似文献
108.
An intramolecular, organocatalyzed Michael addition has been developed to obtain biologically important 2,3‐disubstituted cis‐2,3‐dihydrobenzofurans. By using mandelic acid salts of primary aminocatalysts, derived from cinchona alkaloids, the intramolecular cyclization reaction has been developed to proceed in high yield, with moderate to good diastereoselectivity, and up to 99 % ee. Based on the absolute configuration of the formed 2,3‐disubstituted‐cis‐2,3‐dihydrobenzofurans and by considering the observed substrate scope restrictions, a mechanistic rationalization has been presented. 相似文献
109.
Abstract: Synthesis of bis(2-chlorosulfonylphenyl) diselenide (11) from 2-amino-benzenesulfonic acid was elaborated. It was shown that (11) is a good starting material for synthesis of the organoselenium sulfonamides, such as bis(2-sulfamoylphenyl) diselenides (3) and benz-2,3-azaselenathiophene 1,1-dioxides (4), being potential immunostimulants and oxidation catalysts. 相似文献
110.
Synthesis of two new groups of organoselenium compounds: 2-acyl-and sulfonylbenzisoselenazol-3(2H)-ones (3, 4), potential immunostimulants, in two alternative ways was elaborated. One of them was based on the reaction of 2-chlorobenzoyl chloride (2) with primary amides while the second one involved N-acylation or N-sulfonylation of benzisoselenazol-3(2H)-one (5) with acid chlorides. Two exceptions from general reaction of dichloride 2 with amides were observed. Thioacetamide produced 2,1-benzothiaselenophenone (6), and urea gave 6,7-benzo-2,4-diaza-1-selenacyclohepta-3,5-dione (7). 相似文献