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41.
M. Hasegawa Y. Saitoh S. Yamaguchi H. Takahashi S. Ohnuki 《Hyperfine Interactions》1994,84(1):389-396
Angular correlation of two-photon annihilation radiation (ACAR) measurements have been performed to study the effect of interstitial impurities (O, C and D) on positronium (Ps) formation in irradiation-induced voids of vanadium. It has been observed that Ps formation is sensitively affected by doping with the interstitial impurities, irradiation dose, irradiation temperature, and also by post-irradiation annealing. The Ps component intensity is found to be related to segregation of the interstitial impurities and provides a new experimental method to study void surfaces. 相似文献
42.
Hiroaki Minamisawa Ryoko Okunugi Mayumi Minamisawa Satoshi Tanaka Kazunori Saitoh Nobumasa Arai Masami Shibukawa 《Analytical sciences》2006,22(5):709-713
The solid-phase extraction (SPE) method for the preconcentration of trace amounts of cadmium using synthetic zeolite A-4 and its determination by graphite furnace atomic absorption spectrometry (GFAAS) was investigated. The preconcentration conditions, such as the optimum pH range of the sample solution for the adsorption of cadmium and the kind of acid solution for dissolving the cadmium-adsorbed synthetic zeolite A-4, as well as the measurement conditions for the determination of cadmium by GFAAS, e.g., the ashing and atomizing temperature, were investigated. Quantitative recovery of cadmium onto zeolite A-4 from the sample solution over the pH range 2.0 - 9.0 was achieved by the batch method. After the solid-phase (cadmium-adsorbed zeolite A-4) was separated from the sample solution by a membrane filter, it was dissolved in 2.0 cm(3) of 2.0 mol dm(-3) nitric acid. An aliquot of the resulting solution was injected into the graphite furnace. In GFAAS measurements an alternate gas (Ar, 90%; O(2), 10%) was used as a sheath gas, and the ashing temperature and atomizing temperature were 400 degrees C and 1600 degrees C, respectively. The detection limit (3 sigma) for cadmium was 0.002 microg dm(-3). The relative standard deviation at 0.010 microg dm(-3) was 3.5 - 4.5% (n = 5). The proposed method has been successfully applied to the analysis of trace cadmium in environmental water samples. 相似文献
43.
S. Saitoh H. Tanaka A. Ono Y. Furuhama T. Manabe T. Ihara 《International Journal of Infrared and Millimeter Waves》1986,7(6):795-812
The attenuation of 245.52 GHz millimeter wave was measured through a near ground horizontal path in order to study the anomalous water vapor absorption at the window region. The result demonstrates that the attenuation coefficient includes the quadratic dependence on the water vapor density. The quadratic component of the water vapor density in the expression of the attenuation was assumed to arises from the contribution of water dimers alone, then the concentration of water dimers was estimated adopting the published theoretical water dimers absorption coefficient. The obtained concentration was 0.062% of monomers in number when the water vapor density is 7.5 g/m3. This concentration is in agreement with the published result obtained by way of another method. 相似文献
44.
Highly photoluminescent nanocrystals based on a gold(I) complex and their electrophoretic patterning
Saitoh M Balch AL Yuasa J Tada K Onoda M Nakashima T Kawai T 《Langmuir : the ACS journal of surfaces and colloids》2011,27(17):10947-10952
The fabrication of nanocrystals (NCs) composed of the cationic Au(I) complex was demonstrated by the reprecipitation method in which the colloidal solution of the NCs showed brilliant green phosphorescence with a quantum yield of 83% in n-hexane. Characterization of the prepared NCs was performed by transmission electron microscopy observation and elemental analysis with energy-dispersive X-ray spectroscopy. The obtained Au(I) NCs were particles of random shapes with a diameter of 200-400 nm. The selected-area electron diffraction and X-ray diffraction measurements showed the characteristic diffraction patterns attributable to the crystal structure of the bulk crystal of the Au(I) complex. A similar method was performed with a different counteranion, leading to a colloidal solution of the microcrystals (MCs) with brilliant yellow phosphorescence and a quantum yield of 26% in n-hexane. Luminescence patterning of the NCs and MCs was also achieved successfully by electrophoretic deposition onto an indium tin oxide (ITO)-coated glass substrate, resulting in characteristic luminescence patterns on the ITO substrates with relatively high photoluminescence quantum yields. 相似文献
45.
Tsuyoshi Satoh Yu AwataYuichi Kato Shingo OgataMasashi Ishigaki Shimpei SugiyamaHideki Saitoh 《Tetrahedron》2011,67(6):1102-1113
Treatment of 1-chlorovinyl p-tolyl sulfoxides, which were derived from cyclobutanones and chloromethyl p-tolyl sulfoxide, with lithium enolate of tert-butyl carboxylates, amides, lithium α-sulfonyl carbanions, and lithium α-carbanion of acetonitrile gave adducts in high to quantitative yields. The adducts were treated with Grignard regents, such as i-PrMgCl and EtMgCl in toluene to afford 1-substituted cyclopentenes in good to high yields with one-carbon ring-expansion via 1,2-carbon-carbon (1,2-CC) insertion reaction of the generated magnesium carbenoid intermediates. The magnesium carbenoid 1,2-CC insertion was found to be highly stereospecific. When optically pure chloromethyl p-tolyl sulfoxide was used in this procedure, optically active 1-substituted cyclopentenes were obtained in high optical purity. 相似文献
46.
Itoh A Saitoh T Tani K Uchigaki M Sugimoto Y Yamada J Nakajima H Ohshiro H Sun S Tanahashi T 《Chemical & pharmaceutical bulletin》2011,59(8):947-951
From the embryos of the seeds of Nelumbo nucifera, three bisbenzylisoquinoline alkaloids, nelumboferine and nelumborines A and B, were isolated along with four known compounds, neferine, liensinine, isoliensinine and anisic acid. The structures of the new alkaloids were determined mainly by spectroscopic methods. 相似文献
47.
Machiguchi T Hasegawa T Saitoh H Yamabe S Yamazaki S 《The Journal of organic chemistry》2011,76(13):5457-5460
Through variable-temperature solution-state NMR and molten- and solid-state CP/MAS (13)C NMR spectra, thiotropolone is found to exist as two rapidly equilibrated tautomeric structures, thione and enethiol, even in the solid state far below the melting point. The crystal structure shows an almost perpendicular packing, suggesting that the intramolecular hydrogen bond is dominant. 相似文献
48.
Katsumi Saitoh Koichiro Sera Tadashi Shirai Tatsuji Sato Matsuo Odaka 《Analytical sciences》2003,19(4):525-528
The purpose of this study is to clarify the chemical characterization of PM2.5 and PM10 in diesel exhaust particles (DEP). Sampling of PM2.5 and PM10 in DEP was carried out in November 1999 using an automobile exhaust testing system at the National Traffic Safety and Environment Laboratory, with a diesel truck (engine type: direct injection, displacement: 7,961 cc, carrying weight: 2,020 kg, equivalent inertia weight: 5,600 kg) placed on a chassis dynamometer. Sampling conditions included idling, constant speed of 40 km/h, M-15 test pattern and 60%-revolution/40%-load of maximum power. Samples were collected on a polycarbonate membrane filter (Nuclepore, pore size: 0.8 microm) using a MiniVol Portable Air Sampler (Airmetrics Co., Inc.). The concentrations of several elemental and ionic species in the PM2.5 and PM10 samples were determined by particle induced X-ray emission (PIXE) and ion chromatography analysis. PIXE analysis of the PM2.5 and PM10 samples revealed 15 elements, of which Na, Mg, Si, S, Cl, Ca, Fe and Zn were found to be the major components. Ionic species were Cl-, NO2-, NO3-, SO4(2-), Na+, NH4+, K+ and Ca2+. Concentrations of elements and ionic species under the sampling condition of 60%-revolution/40%-load were highest in comparison with those of the other sampling conditions. The elemental and ionic species data were compared for PM2.5 and PM10; PM2.5 concentrations were 70% or more of PM10 concentrations for the majority of elements, and concentrations of ionic species in PM2.5 and PM10 were almost identical. 相似文献
49.
V. V. Brazhkin Y. Katayama A. G. Lyapin S. V. Popova Y. Inamura H. Saitoh W. Utsumi 《JETP Letters》2005,82(11):713-718
The results of investigating the phase diagrams of ZnCl2 and AlCl3 halides, as well as the structure of the shortrange order of the corresponding melts under pressures up to 6.5 GPa, by the method of energy-dispersive x-ray diffraction are reported. When a ZnCl2 crystal is compressed, a phase transition occurs from the γ phase (HgI2 structure type) to the δ phase (distorted CdI2 structure, WTe2 type). The structural studies of the liquid state of ZnCl2 and AlCl3 indicate that the intermediate-range order decreases rapidly in the tetrahedral network of both melts as the pressure increases to 1.8 and 2.3 GPa for ZnCl2 and AlCl3, respectively. With further compression, the transitions in both melts occur with a change in the structure of the short-range order and with an increase in the coordination number. In this case, the transition in AlCl3 occurs at ≈4 GPa and is a sharp first order transition, whereas the transition in ZnCl2 occurs more smoothly in a pressure range of 2–4 GPa with a maximum intensity near 3 GPa. Thus, the AlCl3 and ZnCl2 compounds exemplify the existence of two phenomena—gradual decay of intermediate-range structural correlations and a sharper liquid-liquid coordination transition. 相似文献
50.
N. Hashimoto T.R. Saitoh G. Sletten R.A. Bark M. Bergström K. Furuno T. Komatsubara T. Shizuma S. Törmänen P.G. Varmette 《The European Physical Journal A - Hadrons and Nuclei》1998,2(4):327-330
Abstact: High-spin states in 183Re have been studied using the 176Yb(11B,4n) reaction at 52 and 57 MeV. Two high-K bands have been observed directly by a time-correlated γ-γ coincidence measurement. One of the bands is built on an isomeric
K
π=(25/2)+ state at E
x= 1908 keV with a half-life of 0.82(2) ms. The other band, assigned as K
π=(29/2)− at E
x= 2739 keV, decays to the (25/2)+ band. These bands are interpreted as three-quasiparticle structures, π(5/2)+[402] &⊗ν(9/2)+[624] ⊗ν(11/2)+[615] for the (25/2)+ band and π(9/2)−[514] ⊗ν(9/2)+[624] ⊗ν(11/2)+[615] for the (29/2)− band. The K
π= (29/2)− band becomes strongly Coriolis mixed with increasing spin and is gradually changing into a low-K s-band structure.
Received: 20 April 1998 相似文献