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101.
A convenient synthesis method of antisepsis agent TAK-242 ((R)-1) through diastereomeric resolution was developed. By condensation of racemate rac-1 with chiral acid (S)-O-acetylmanderic acid (6a), the desired diastereomer 5a was isolated with 98% de in 39% yield by simple crystallization. Deacylation of 5a with aq NaOH followed by recrystallization provided (R)-1 with 99% ee in 20% yield from rac-1. 相似文献
102.
Zhang G Jin W Fukushima T Kosaka A Ishii N Aida T 《Journal of the American Chemical Society》2007,129(3):719-722
A newly designed Gemini-shaped hexabenzocoronene amphiphile (1), carrying an isothiouronium ion-appended side chain, self-assembles in CH2Cl2 to form a nanotubular object, whose graphitic wall is densely covered by a positively charged molecular layer of isothiouronium ion pendants. The graphitic nanotube can be dispersed uniformly in aqueous media owing to effective hydration as well as electrostatic repulsion. Post-supramolecular functionalization of the nanotube surface is possible, without disruption of the tubular morphology, by taking advantage of a specific interaction of the isothiouronium ion pendants with oxoanion guests. Mixing with sodium poly(4-styrenesulfonate) results in wrapping of the nanotube, while complexation with an electron-accepting oxoanion such as anthraquinone carboxylate allows photoinduced electron transfer from the graphitic wall to the bound guest molecules. 相似文献
103.
Mikio Fukuhara Yoshiyuki Kuwano Atsuko Tsugane Masamitsu Yoshida 《Journal of Polymer Science.Polymer Physics》1999,37(6):497-503
Thermal degradation of NBR and CR heated in air was determined by analysis of diffracted SH ultrasonic waves. Thermal degradation was evaluated by examining wave pattern characteristics of SH waves passing through the surface depth between transmitter and receiver. Thermal crosslinking of main chains in thermally degraded NBR and CR, accompanied by lowering of mechanical properties, can evaluate by decrease of launched time and appearance of 0.9 MHz side peak of the power spectrum. The thermal degradation also causes phase delay at high frequencies, showing regression of viscoelasticity associated with formation of dangling ends. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 497–503, 1999 相似文献
104.
Yoshiaki Shoji Miki Kobayashi Atsuko Kosaka Rie Haruki Reiji Kumai Shin-ichi Adachi Takashi Kajitani Takanori Fukushima 《Chemical science》2022,13(34):9891
The alignment control of discotic columnar liquid crystals (LCs), featuring a low motility of the constituent molecules and thus having a large viscosity, is a challenging task. Here we show that triphenylene hexacarboxylic ester, when functionalized with hybrid side chains consisting of alkyl and perfluoroalkyl groups in an appropriate ratio, gives a hexagonal columnar (Colh) LC capable of selectively forming large-area uniform homeotropic or homogeneous alignments, upon cooling from its isotropic melt or upon application of a shear force at its LC temperature, respectively. In addition to the alignment switching ability, each alignment state remains persistent unless the LC is heated to its melting temperature. In situ X-ray diffraction analysis under the application of a shear force, together with polarized optical microscopy observations, revealed how the columnar assembly is changed during the alignment-switching process. The remarkable behavior of the discotic LC is discussed in terms of its rheological properties.A columnar liquid crystal consisting of a triphenylene hexacarboxylic ester mesogen and semifluoroalkyl side chains shows complete switching between homeotropic and homogeneous alignments, each of which remains persistent up to its melting point. 相似文献
105.
Theerayuth Plirdpring Ken Kurosaki Atsuko Kosuga Manabu Ishimaru Yuji Ohishi Hiroaki Muta Shinsuke Yamanaka 《固体物理学:研究快报》2012,6(4):154-156
Cu2Ga4Te7 has recently been reported to have a relatively high thermoelectric (TE) figure of merit (ZT). However, the TE properties of Cu2In4Te7, which has the same defect zinc‐blende structure as Cu2Ga4Te7, have been hardly investigated. Here, we demonstrate that Cu2In4Te7 has relatively high ZT values that are similar to those of Cu2Ga4Te7. High‐density polycrystalline bulk samples of Cu2In4Te7 were prepared and their electrical resistivity (?), Seebeck coefficient (S), and thermal conductivity (κ) were measured. Cu2In4Te7 has a maximum ZT of 0.3 at 700 K, with ?, S, and κ values of 62.1 × 10–5 Ω m, 394 μV K–1, and 0.61 W m–1 K–1, respectively. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
106.
107.
A new strategy for synthesizing quinolizidine skeletons by reductive cyclization via acylpyridinium cations was developed. Several functional groups, including carbonyl, silyl, and acetal, were tolerated under mild reaction conditions. The reaction was successfully extended to a one-pot synthesis of a bicyclic compound, and the synthetic strategy was applied to concise total syntheses of quinolizidines 207I and 1-epi-207I, without protecting groups. 相似文献
108.
A cytidine 5'-monophosphate (CMP)-sialic acid analogue carrying a fluorescent reporter group, an inhibitor of sialyltransferase, was synthesised in order to investigate glycan synthesis events in cells. The compound was found to be a substrate of a CMP-sialic acid transporter, and specific Golgi vesicles were visualised in the cells. 相似文献
109.
Yukiko Maekawa Makiko Sugiura Atsuko Takeuchi Koji Tomoo Toshimasa Ishida Miyoko Kamigauchi 《Helvetica chimica acta》2010,93(5):991-998
The Advanced Glycation End Products (AGEs) are the causative substances of lifestyle‐habit illness. To elucidate the glycation mechanism of the protein, the reaction of lysozyme with D ‐glucose was analyzed by the fluorescence, TOF‐MS, and 13C‐NMR spectroscopy under the physiological condition. The fluorescence intensity of lysozyme in the glycation solution increased proportionally with a reaction time of ten weeks. The MALDI‐TOF‐MS spectra of the reaction solution after two weeks showed a peak at m/z 15066, which indicated the presence of a larger molecule than the native lysozyme (m/z 14331), and new peaks at m/z 30105 (dimer) and 45000 (trimer) were also observed. The spectral analysis supported the assumption of a continuous glycation reaction of D ‐glucose with lysozyme and a 30% transformation of lysozyme to the dimeric form during ten weeks. The 13C‐NMR spectra of lysozyme showed six [13C]‐labeled signals by the glycation reaction with [13C]‐glucose after two weeks of reaction. The combined analysis of TOF‐MS and 13C‐NMR spectra uncovered that first products of the glycation reaction of lysozyme with D ‐glucose can be observed already three hours after starting the reaction and that nine D ‐glucose units are attached during ten weeks at 37°. 相似文献
110.