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91.
Liquid‐Crystalline Biomacromolecular Templates for the Formation of Oriented Thin‐Film Hybrids Composed of Ordered Chitin and Alkaline‐Earth Carbonate
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Dr. Tatsuya Nishimura Ken Toyoda Takahiro Ito Dr. Yuya Oaki Yukiko Namatame Prof. Takashi Kato 《化学:亚洲杂志》2015,10(11):2356-2360
Macroscopically ordered inorganic thin films have been formed on unidirectionally oriented, liquid‐crystalline chitin matrices. In the presence of poly(acrylic acid) (PAA), unidirectionally oriented chitin films act as templates for the formation of oriented thin‐film crystals of alkaline‐earth carbonates such as SrCO3 and BaCO3. The morphology and orientation of crystals are dependent on the metal ion concentration. For SrCO3 crystallization, unidirectional thin films and hexagonal‐shaped thin films have been deposited from 200 and 25 mm concentration strontium solutions, respectively. 相似文献
92.
Y. Tobari K. Koba K. Fukushima N. Tokuchi N. Ohte R. Tateno S. Toyoda T. Yoshioka N. Yoshida 《Rapid communications in mass spectrometry : RCM》2010,24(9):1281-1286
Evaluation of the openness of the nitrogen (N) cycle in forest ecosystems is important in efforts to improve forest management because the N supply often limits primary production. The use of the oxygen isotope ratio (δ18O) of nitrate is a promising approach to determine how effectively atmospheric nitrate can be retained in a forest ecosystem. We investigated the δ18O of nitrate in stream water in order to estimate the contribution of atmospheric NO in stream‐water NO (fatm) from 26 watersheds with different stand ages (1–87 years) in Japan. The stream‐water nitrate concentrations were high in young forests whereas, in contrast, old forests discharged low‐nitrate stream water. These results implied a low fatm and a closed N cycle in older forests. However, the δ18O values of nitrate in stream water revealed that fatm values were higher in older forests than in younger forests. These results indicated that even in old forests, where the discharged N loss was small, atmospheric nitrate was not retained effectively. The steep slopes of the studied watersheds (>40°) which hinder the capturing of atmospheric nitrate by plants and microbes might be responsible for the inefficient utilization of atmospheric nitrate. Moreover, the unprocessed fraction of atmospheric nitrate in the stream‐water nitrate in the forest (funprocessed) was high in the young forest (78%), although funprocessed was stable and low for other forests (5–13%). This high funprocessed of the young forest indicated that the young forest retained neither atmospheric NO nor soil NO effectively, engendering high stream‐water NO concentrations. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
93.
Shigeo Hayakawa Shinya Matsumoto Mami Hashimoto Kenichi Iwamoto Hirofumi Nagao Michisato Toyoda Yasushi Shigeri Michiko Tajiri Yoshinao Wada 《Journal of the American Society for Mass Spectrometry》2010,21(9):1482-1489
Post-translational modifications (PTMs) of proteins are important in the activation, localization, and regulation of protein
function in vivo. The usefulness of electron capture dissociation (ECD) and electron-transfer dissociation (ETD) in tandem
mass spectrometry (MS/MS) using low-energy (LE) trap type mass spectrometer is associated with no loss of a labile PTM group
regarding peptide and protein sequencing. The experimental results of high-energy (HE) collision induced dissociation (CID)
using the Xe and Cs targets and LE-ETD were compared for doubly-phosphorylated peptides TGFLT(p)EY(p)VATR (1). Although HE-CID using the Xe target did not provide information on the amino acid sequence, HE-CID using the Cs target
provided all the z-type ions without loss of the phosphate groups as a result of HE-ETD process, while LE-ETD using fluoranthene
anion gave only z-type ions from z5 to z11. The difference in the results of HE-CID between the Xe and Cs targets demonstrated that HE-ETD process with the Cs target
took place much more dominantly than collisional activation. The difference between HE-ETD using Cs targets and LE-ETD using
the anion demonstrated that mass discrimination was much weaker in the high-energy process. HE-ETD was also applied to three
other phosphopeptides YGGMHRQEX(p)VDC (2: X = S, 3: X = T, 4: X = Y). The HE-CID spectra of the doubly-protonated phosphopeptides
(= [M + 2H]2+) of 2, 3, and 4 using the Cs target showed a very similar feature that the c-type ions from c7 to c11 and the z-type ions from z7 to z11 were formed via N-Cα bond cleavage without a loss of the phosphate group. 相似文献
94.
Microperforated panels (MPPs) can provide wide-band absorption without fibrous and porous materials and are recognized as next-generation absorption materials. Although the fundamental absorbing mechanism of an MPP absorber is Helmholtz-resonance absorption, sound-induced vibration of an MPP itself can affects the absorption characteristics. There have been some studies considering the effects of the sound-induced vibration and there even is a proposal to widen the absorption bandwidth by positively utilizing the vibration of an MPP itself. On the other hand, in a previous study, the relationship between MPP absorbers and panel-type absorbers was investigated with infinite theory. However, the relationship between Helmholtz-resonance absorption and panel-type absorption in finite flexible MPP absorbers has not been clarified. Herein, from the viewpoint of an absorption-characteristics transition with the perforation ratio, the relationship between Helmholtz-resonance absorption and panel-type absorption including the effects of eigen-mode vibrations of the panel is theoretically and experimentally investigated. The analytical model considers a finite flexible MPP supported in a circular duct, and the predicted data for the absorption coefficient under normal incidence is validated by an experiment using an acoustic tube. From this investigation, it is found that panel-type absorption due to eigen-mode vibrations of the panel occurs independently from Helmholtz-resonance absorption, while panel-type absorption due to a mass-spring resonance of a panel and a back cavity has a trade-off relationship with Helmholtz-resonance absorption with respect to the perforation ratio. 相似文献
95.
Fujihisa H Akahama Y Kawamura H Ohishi Y Shimomura O Yamawaki H Sakashita M Gotoh Y Takeya S Honda K 《Physical review letters》2006,97(8):085503
Despite many experimental and theoretical studies, the crystal structure of the epsilon phase of solid oxygen has not been determined. We performed powder x-ray diffraction experiments and the Rietveld analyses in this study to show that a new arrangement of the monoclinic space group C2/m could fit the diffraction patterns of the epsilon phase and obtained a structure that consisted of an O8 cluster with 4 molecules. The dependence of the lattice parameters, the molar volume, and the intermolecular distances on the pressure was investigated. 相似文献
96.
Brillouin scattering is an efficient nondestructive and noncontact measurement method to obtain the wave properties of thin layers at hypersonic frequencies. The reflection induced ThetaA (RIThetaA) scattering geometry enables the simultaneous measurement of the phonons, which propagate in each direction of wave vectors of q(Theta A) (propagation in the film plane) and q(180) (back scattering). Using this scattering geometry, we could observe the refractive indices and birefringence of the piezoelectric poly-vinylidene fluoride (PVDF) film as a function of temperature. By introducing the microscopic technique, the elastic anisotropy and refractive index measurements in the minute area of polycrystalline ZnO films were also performed. 相似文献
97.
Tetracyanoethylene oxide (TCNEO) reacted with [CpCo(dithiolene)] (Cp = η5-cyclopentadienyl) complexes having 4-pyridyl or 3-pyridyl group to undergo a dicyanomethylation to the nitrogen atom on the pyridyl group. The reaction of [CpCo(S2C2(4Py)2)] (1) with TCNEO formed both the monodicyanomethylated [CpCo(S2C2(4Py)(4Py-C(CN)2))] (1a) and bisdicyanomethylated [CpCo(S2C2(4Py-C(CN)2)2)] (1b). [CpCo(S2C2(2Py)(4Py))] (2) reacted with TCNEO to give [CpCo(S2C2(2Py)(4Py-C(CN)2))] (2a) but no dicyanomethylation occurred on the 2-pyridyl group. 2 reacted with excess TCNEO to form the only dicyanomethylated acetylene derivative 2Py-CC-(4Py-C(CN)2) (2c), followed by a dissociation of the CpCoS2 fragment. The monodicyanomethylated [CpCo(S2C2(nPy-C(CN)2)(2-thienyl))] (n = 4 (4a) or 3 (5a)) complexes were also prepared from [CpCo(S2C2(nPy)(2-thienyl))] (n = 4 (4) or 3 (5)) and TCNEO. 1b was structurally characterized by X-ray diffraction study. The all dicyanomethylated [CpCo(dithiolene)] complexes showed the dithiolene LMCT absorption in the range of 605-644 nm (ε = 7000-9200 M−1 cm−1) and very strong absorption due to their pyridinium-dicyanomethylide moieties in near-UV region (e.g. 1b: λmax = 470 nm, ε = 43,400 M−1 cm−1). The CV of the all dicyanomethylated complexes exhibited two reduction waves. The first reduction is due to CoIII/CoII and the second one is due to the reduction of the pyridinium-dicyanomethylide moiety. The reduced 1b− is stable enough for several minutes according to the visible spectroelectrochemical measurement. The ESR spectrum of 1b− indicated eight hyperfine splittings due only to the interaction with the nuclear spin of cobalt (I = 7/2). 相似文献
98.
99.
Ryu I Miyazato H Kuriyama H Matsu K Tojino M Fukuyama T Minakata S Komatsu M 《Journal of the American Chemical Society》2003,125(19):5632-5633
Free-radical mediated stannylcarbonylation of azaenynes provides a general [n + 1]-type annulation approach leading to alpha-stannylmethylene lactams. The cyclization is unusual in its breadth, covering 4-exo, 5-exo, 6-exo, 7-exo, and 8-exo modes. 相似文献
100.
Itsuo Mori Takako Matsuo Yoshikazu Fujita Minako Toyoda Kenichi Ichitani Noriko Inoue 《Fresenius' Journal of Analytical Chemistry》1994,348(5-6):346-349
Summary A spectrofluorophotometric determination of thallium(III) is proposed. It is based on the enhancement of the fluorescence reaction of 3,4,5,6-tetrachlorofluorescein (TCF) with Pyrogallol Red (PR) by thallium(III) in the presence of Swanol (AM 301, lauryldimethyl aminoacetic acid betain) as an amphoteric surfactant. The method was found to be suitable for the determination of thallium(III) down to 4.0 g in 10.0 ml by measuring the difference in the relative fluorescence intensities of a TCF/PR/thallium(III) solution and a TCF/PR solution. The recovery test in artificial urine was satisfactory (96±2%). 相似文献