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91.
The consecutive reaction of bis [ 2, 2, 2-trifluoroethyl] phosphite and its application to the one-pot synthesis of 3-cyano-β, γ-unsaturated nitriles with exdusive or predominant E-selectivity (E: Z = 100-85: 0-15) and excellent yields (94%-99%) are described. 相似文献
92.
Toshifumi Tsuda 《Tetrahedron》2005,61(45):10719-10733
A direct and practical method for the construction of β-mannosidic linkages is described. While β-selectivities in the TMSOTf-promoted glycosidation of 2,3,4,6-tetra-O-benzyl-d-mannosyl diethyl phosphite are found to be highly dependent on the reactivity of acceptor alcohols, 2,3-di-O-benzyl-4,6-O-benzylidene-d-mannosyl diethyl phosphite reacts with a wide range of acceptor alcohols in the presence of TMSOTf in CH2Cl2 at −45 °C to give β-mannosides in high yields with good to high β-selectivities. 相似文献
93.
X-ray crystal structure analyses of (CH3NCO)3 (M) and (ClNCO)3·1/2C2H4Cl2 (C) were carried out at room temperature (MoK, graphite monochromator, =0.71069 Å): 1.M=171.16, monochlinic, P21/c,a=14.848 (1) Å,b=13.400 (2) Å,c=8.149 (1) Å, =100.87 (1)°,V=1 592.3 Å3,Z=8,F(000)=720,d
x
=1.428 Mgm–3, =76m–1,R=6.51%,R
w
=7.01% (964 reflections, 218 parameters). 2.M=281.89, monochlinic, P 21/c,a=9.416 (3) Å,b=5.728 (1) Å,c=18.199 (8) Å, =98.64 (2)°,V=970.4 Å3,Z=4,F(000)=556,d
x
=1.929 Mgm–3, =1.11 mm–1,R=3.96%,R
w
=3.44% (605 reflections, 132 parameters). The ring systems together with the C atoms of the methyl groups in (M) and with the Cl atoms in (C) are planar and have D3h-symmetry. Bond lengths and bond angles are discussed with regard to14N-NQR,35Cl-NQR and vibrational spectroscopic data. 相似文献
94.
N. N. Kabal'nova V. V. Shereshovets A. S. Vorob'ev I. A. Rusakov I. I. Furlei Yu. I. Murinov 《Russian Chemical Bulletin》1993,42(12):2045-2047
The rate constants for the quenching of singlet oxygen by sterically hindered phenols were determined. It was observed that the rate constant for the quenching increases with a decrease in the ionization potential of phenols.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2132–2134, December, 1993.This work was supported by the Russian Foundation for Basic Research (Grant 93-03-5231). 相似文献
95.
迄今, 在中温水热条件下已合成了大量具有空旷骨架结构的过渡金属磷酸盐微孔材料[1], 这类材料在非线性光学材料、磁性材料、超导材料及催化等诸多方面具有潜在的应用前景[2~5]. 相似文献
96.
Elena I. Lozinskaya Alexander S. Shaplov Mariya V. Kotseruba Lidiya I. Komarova Konstantin A. Lyssenko Mikhail Y. Antipin Denis G. Golovanov Yakov S. Vygodskii 《Journal of polymer science. Part A, Polymer chemistry》2006,44(1):380-394
The new convenient method for the synthesis of high molecular weight aromatic poly(1,3,4‐oxadiazole)s (PODs) has been proposed. These polymers were prepared by “one‐pot” procedure from dicarboxylic acid and hydrazine's salt (sulfate, phosphate) or dicarboxylic acid dihydrazides. The mixture of ionic liquid and triphenyl phosphite was used both as a solvent and condensing agent. The polycyclization occurred at a sufficiently low temperature of 210 °C for 2–5 h and resulted in obtaining film‐forming PODs having inherent viscosities up to 0.9 dL/g and good thermal stability. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 380–394, 2006 相似文献
97.
Synthesis of 1,2-dihydroisoquinolin-1-ylphosphonates via CuI-catalyzed three-component tandem reactions of 2-(2-formylphenyl)ethanone, amine, and diethyl phosphite is described. The reactions proceed smoothly under mild conditions leading to the desired products in good yields. 相似文献
98.
Jennifer M. Butler Troy E. Knight Sohrob Sotoudehnia Paul D. Kadle Jr. Susan L. Green Gary M. Gray 《Journal of chemical crystallography》2004,34(2):111-118
The X-ray crystal structures of four closely related Mo(CO)5(R2PXR) (R2 = OCH2CMe2CH2O, XR = S-2-Pr, NHC6H4-4-Me; R2 = Ph2, XR = NHC6H4-2-Me, OC6H4-4-SMe) complexes have been determined. The R2PXR ligands are oriented so that the P—X bond and one of the Mo—C bonds are nearly eclipsed. This results in the distortion of the octahedral coordination geometry via tilting of the Mo(CO)5 group away from the XR group. As observed in related complexes, the Mo—C bond of the carbonyl trans to the phosphorus-donor group is shorter than are the Mo—C bonds of the carbonyls trans to carbonyls. In contrast, no significant differences were observed between the Mo—C bonds of carbonyls trans to phosphites and the Mo—C bonds of carbonyls trans to phosphinites. The conformations of the 1,3,2-dioxaphosphorinanes were distorted chairs with the P end of the chair significantly flattened relative to the seat of the chair. This conformation is similar to that which has been observed for 1,3,2-dioxaphosphorinanes in other transition metal complexes. 相似文献
100.
Morteza Ziaee Mostafa Yourdkhani 《Journal of polymer science. Part A, Polymer chemistry》2021,59(15):1732-1739
In thermal frontal polymerization (FP), ambient temperature and staging conditions highly affect the resin behavior and front properties. This study describes the effect of staging conditions and resin reactivity on frontal ring opening metathesis polymerization of dicyclopentadiene in presence of phosphite-inhibited second-generation Grubbs catalyst. An experimental setup is designed to characterize and understand the effect of inhibitor concentration, incubation time, and incubation temperature on front velocity, activation time, and front temperature of the FP reaction. The results reveal that front properties are influenced by various factors, including available energy density of resin, stability of catalyst-inhibitor complex, resin temperature, and resin viscosity. An increase in staging temperature results in lower pot lives but faster gelation process and activation of FP reaction. Additionally, increasing the inhibitor concentration leads to slower fronts, higher activation times, and longer pot lives. The results of this study can be extended to other FP systems and can be used in design of new manufacturing processes and applications using FP. 相似文献