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81.
Dr. Nobuto Yoshinari Dr. Natthaya Meundaeng Dr. Hiroyasu Tabe Prof. Yusuke Yamada Dr. Satoshi Yamashita Prof. Yasuhiro Nakazawa Prof. Takumi Konno 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(41):18204-18209
Postsynthetic installation of lanthanide cubanes into a metallosupramolecular framework via a single-crystal-to-single-crystal (SCSC) transformation is presented. Soaking single crystals of K6[Rh4Zn4O(l -cys)12] (K6[ 1 ]; l -H2cys=l -cysteine) in a water/ethanol solution containing Ln(OAc)3 (Ln3+=lanthanide ion) results in the exchange of K+ by Ln3+ with retention of the single crystallinity, producing Ln2[ 1 ] ( 2Ln ) and Ln0.33[Ln4(OH)4(OAc)3(H2O)7][ 1 ] ( 3Ln ) for early and late lanthanides, respectively. While the Ln3+ ions in 2Ln exist as disordered aqua species, those in 3Ln form ordered hydroxide-bridged cubane clusters that connect [ 1 ]6− anions in a 3D metal-organic framework through coordination bonds with carboxylate groups. This study shows the utility of an anionic metallosupramolecular framework with carboxylate groups for the creation of a series of metal cubanes that have great potential for various applications, such as magnetic materials and heterogeneous catalysts. 相似文献
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M Ono Y Takaki M Takatsuji K Akiyama M Okawa J Kinjo H Miyashita H Yoshimitsu T Nohara 《Chemical & pharmaceutical bulletin》2012,60(8):1083-1087
Three new resin glycosides, quamoclins V (1), VI (2), and VII (3) and a new tetrahydropyran derivative, quamopyran (4), were isolated from the seeds of Quamoclit pennata BOJER (Convolvulaceae). The chemical structures of these compounds were determined primarily on the basis of spectroscopic data. The carboxyl group of the aglycone, 11S-convolvulinolic acid, of 1 and 2 was linked intermoleculary with a hydroxy group of the sugar moiety to form a macrocyclic ester structure, as in already known jalapins, and 3 was an acylated glycosidic acid methyl ester. All of the sugar moieties of 1-3 were acylated by one 2S-methylbutyric acid. Compound 4 was a diketone having a tetrahydropyran ring. 相似文献
85.
Inoue K Ikemura A Tsuruta Y Tsutsumiuchi K Hino T Oka H 《Biomedical chromatography : BMC》2012,26(2):137-141
We developed a high-throughput method based on on-line solid-phase extraction liquid chromatography tandem mass spectrometry (SPE-LC-MS/MS) to determine N-terminal thymosin-β fragment peptide (N-acetyl-seryl-aspartyl-lysyl-proline, Ac-SDKP) in human plasma samples. Quantification of Ac-SDKP was performed using direct injection for on-line SPE based on C(18), reversed-phase LC separation and stable isotope dilution electrospray ionization-MS/MS in multiple reaction-monitoring (MRM) mode. The Ac-SDKP-(13)C(6), (15)N(2) (m/z 496 → 137) was synthesized for the internal standard. The MRM ion for Ac-SDKP was m/z 488 → 129 (quantitative ion)/226. The limit of detection and lower limit of quantitation were 0.05 and 0.1 ng/mL in standard solution, respectively. Recovery values were 98.3-100.4% with inter-day (relative standard deviation, RSD, 0.4-14.1%) and intra-day (RSD, 0.8-19.7%) assays. This method was applied to the measurement of Ac-SDKP levels in plasma from hemodialyzed subjects. Concentrations were 0.59 ± 0.23 ng/mL (pre-hemodialyzed subjects, n = 9) and 0.44 ± 0.19 ng/mL (post-hemodialyzed subjects, n = 9). All plasma Ac-SDKP levels were decreased by dialysis. Thus, plasma Ac-SDKP was decreased through dialysis in chronic kidney disease. The findings in this study will be useful for the treatment of anemia in chronic kidney disease with dialysis. 相似文献
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Kosuke Igawa Nobuto Yoshinari Takumi Konno 《Acta Crystallographica. Section C, Structural Chemistry》2012,68(9):o332-o334
The asymmetric unit of the optically resolved title salt, C8H12N+·C4H5O4S−, contains a 1‐phenylethanaminium monocation and a thiomalate (3‐carboxy‐2‐sulfanylpropanoate) monoanion. The absolute configurations of the cation and the anion are determined to be S and R, respectively. In the crystal, cation–anion N—H...O hydrogen bonds, together with anion–anion O—H...O and S—H...O hydrogen bonds, construct a two‐dimensional supramolecular sheet parallel to the ab plane. The two‐dimensional sheet is linked with the upper and lower sheets through C—H...π interactions to stack along the c axis. 相似文献
88.
Mingdeng Wei Yoshinari Konishi Hideki Sugihara Hironori Arakawa 《Solid State Communications》2005,133(8):493-497
Nanotubes TiO2 were synthesized from layered titanate Na2Ti3O7 particles by a soft chemical process. These nanotubes have a hollow structure with an opening end. The wall of nanotubes is very well crystallized multi-wall structure. The inner diameters of nanotubes are ca. 30-40 nm and the length up to several hundreds nanometers. XRD results show that TiO2 phase was formed during the procedure of exfoliating Na2Ti3O7 particles into nanosheets. Based on our experimental results, an exfoliating-rolling model was proposed for formation of nanotube structure. 相似文献
89.
Iron fluoride thin films were successfully grown by Pulsed Laser Deposition (PLD), and their physico-chemical properties and electrochemical behaviours were examined by adjusting the deposition conditions, such as the target nature (FeF2 or FeF3), the substrate temperature (Ts ≤ 600 °C), the gas pressure (under vacuum or in oxygen atmosphere) and the repetition rates (2 and 10 Hz). Irrespective of the FeF2 or FeF3 target nature, iron fluoride thin films, deposited at 600 °C under vacuum, showed X-ray diffraction (XRD) patterns corresponding to the FeF2 phase. On the other hand, iron fluoride thin films deposited at room temperature (RT) from FeF2 target were amorphous, whereas the thin films deposited from FeF3 target consisted of a two-phase mixture of FeF3 and FeF2 showing sharp and broad diffraction peaks by XRD, respectively. Their electrochemical behaviour in rechargeable lithium cells was investigated in the 0.05-3.60 V voltage window. Despite a large irreversible capacity on the first discharge, good cycling life was observed up to 30 cycles. Finally, their electrochemical properties were compared to the ones of iron oxide thin films. 相似文献
90.
Aiming at improving the durability of anodic electrochromic nickel oxide thin films, Ni-M-O (M = Co, Ta) thin films were grown by pulsed laser deposition (PLD), using optimized conditions, namely room temperature and 10−1 mbar oxygen pressure. For low Co and Ta contents (<5%), both additions lead to a loss of the [1 1 1] preferred orientation of the NiO rock-salt structure followed by a film amorphization with increasing Ta amount. Among the two series of metal additions (M ≤ 20%), the Ni-Co-O (5% Co) and Ni-Ta-O (10% Ta) thin films show the highest electrochemical performances especially in respect of improved durability. If the enhanced properties are associated with a limited dissolution of the oxidized phase for the Ni-Ta-O system, the opposite trend is observed for the Ni-Co-O system as compared to pure NiO. 相似文献