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51.
Controlled Synthesis of Diphosphine-Protected Gold Cluster Cations Using Magnetron Sputtering Method
Lewei Wang Tsubasa Omoda Kiichirou Koyasu Tatsuya Tsukuda 《Molecules (Basel, Switzerland)》2022,27(4)
We demonstrated, for the first time, atomically precise synthesis of gold cluster cations by magnetron sputtering of a gold target onto a polyethylene glycol (PEG) solution of 1,3-bis(diphenylphosphino)propane (Ph2PCH2CH2CH2PPh2, dppp). UV-vis absorption spectroscopy and electrospray ionization mass spectrometry revealed the formation of cationic species, such as [Au(dppp)n]+ (n = 1, 2), [Au2(dppp)n]2+ (n = 3, 4), [Au6(dppp)n]2+ (n = 3, 4), and [Au11(dppp)5]3+. The formation of [Au(dppp)2]+ was ascribed to ionization of Au(dppp)2 by the reaction with PEG, based on its low ionization energy, theoretically predicted, mass spectrometric detection of deprotonated anions of PEG. We proposed that [Au(dppp)2]+ cations thus formed are involved as key components in the formation of the cluster cations. 相似文献
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S. Kubono N. Ikeda M. Yasue T. Nomura Y. Fuchi H. Kawashima S. Kato H. Orihara T. Shinozuka H. Ohnuma H. Miyatake T. Shimoda 《Zeitschrift für Physik A Hadrons and Nuclei》1988,331(3):359-360
The first excited state above the p +19Ne threshold in20Na has been identified at 2.637 MeV (± 15 keV) with Jπ=0+ or 1+ from the20Ne(3He, t)20Na reaction, suggesting this state to be the s-wave resonance in the p +19Ne scattering at stellar energies. 相似文献
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The recent progress made on transformations involving the reactions between aryne intermediates and organosulfur compounds has been reviewed. A wide variety of aromatic organosulfurs are now synthesizable by generating arynes in the presence of organosulfur compounds. Organosulfurs have distinctive reactivities with arynes, which depend on the sulfur atom’s valence state, that is, S(II), S(IV), and S(VI), as well as the presence or absence of other intra- or intermolecular reactive moieties. These novel transformations have enabled the diversity-oriented synthesis of unique aromatic organosulfurs that were once difficult to prepare by the conventional methods, paving the way for the development of molecules that are beneficial across numerous disciplines, including pharmaceutical science and materials science. 相似文献
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Wen Xi Chia Mayu Nishijo Seongsoo Kang Dr. Juwon Oh Tsubasa Nishimura Dr. Hiroto Omori Dr. Jean-François Longevial Prof. Dr. Yoshihiro Miyake Prof. Dr. Dongho Kim Prof. Dr. Hiroshi Shinokubo 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(12):2754-2760
N-Alkylation significantly changes the electronic and optical properties, as well as the reactivity of nitrogen-containing π-conjugated molecules. In this study, it is found that treating 5,15-diazaporphyrins with methyl triflate selectively affords the corresponding N-methyl-5,15-diazaporphyrinium cations in good yield. N-Methylation substantially alters the electronic properties and reactivity of diazaporphyrins. The electron-accepting properties of the N-methyl-5,15-diazaporphyrinium cations are enhanced due to their lowered LUMO level. Stabilization of the LUMO energy enables regio- and stereoselective Diels–Alder reactions of the cationic diazaporphyrin with cyclopentadiene. N-Methylation also enhances the acidity of the inner NH protons, and thus, allows facile deprotonation to provide nitrogen-substituted isoporphyrin analogues with only one NH group in the central cavity. 相似文献
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Two new polyacetylenes, 1-hydroxydihydropanaxacol (3) and 17-hydroxypanaxacol (4), were isolated from Panax ginseng hairy root culture, along with dihydropanaxacol (1), panaxacol (2) and ginsenoyne D (5). Highly hydroxylated compounds 1-4 were isolated from the medium and compound 5, which was a biosynthetic precursor of compound 1, was isolated from the roots. Compounds 1-4 showed antimicrobial activity against Staphylococcus aureus, Bacillus subtilis, Cryptococcus neoformans and Aspergillus fumigatus. It is suggested that P. ginseng plants release antimicrobial polyacetylenes into the surrounding soil from the roots as defense compounds. 相似文献