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71.
Tomiyasu M Obata T Nonaka H Nishi Y Nakamoto H Takayama Y Ikehira H Kanno I 《Magnetic resonance imaging》2008,26(4):572-576
To evaluate the contamination of glycogen signal synthesized in skeletal muscle by that in the liver, long-term monitoring of over 7 h of in vivo [1-13C] glycogen synthesis/degradation at the right abdomen and left shoulder was achieved using a 3.0-T clinical MR system. 13C MR spectra without localization were obtained from five healthy volunteers before and after oral administration of 85 g of d-glucose, including 10 g of 99% [1-13C] glucose. In all volunteers, the relative signal intensities at the abdomen to those at shoulder were about two- to fivefold, and those of time-course changes at the abdomen and shoulder were dissimilar. It is considered that the quantity of muscle-synthesized glycogen signal at the abdomen is less than that at the shoulder because of the lesser muscle volume at the abdomen, and it may be less affected for evaluating glycogen synthesis/degradation in the liver even without localization pulses. 相似文献
72.
Yamamoto M Kashiwagi Y Nakamoto M 《Langmuir : the ACS journal of surfaces and colloids》2006,22(20):8581-8586
Monodispersed silver nanoparticles capped by long-chain alkyl carboxylates were prepared by the reaction of silver carboxylate with tertiary amine at 80 degrees C for 2 h. This approach is a unique, size-controlled synthetic method for the large-scale preparation of silver nanoparticles. Long-chain alkyl carboxylate derived from a precursor acts as a stabilizer to avoid the aggregation of silver nanoparticles and to control particle size. In addition, amine plays an important role both as a reagent to form a thermally unstable, amine-coordinated intermediate, bis(amine)silver(I) carboxylate, and as a mild reducing agent for the intermediate to produce nanoparticles at a low temperature. The silver core and carboxylate-capping ligand of silver nanoparticles were characterized by various techniques such as transmission electron microscopy, optical absorption spectroscopy, powder X-ray diffraction, X-ray photoelectron spectroscopy, gas chromatograph mass spectroscopy, and thermogravimetric and differential thermal analysis. The diameter of the nanoparticles can be strongly influenced by the alkyl chain length and the structure of the carboxylate. The average diameters of the silver nanoparticles were controlled to less than 5 nm in the case of silver carboxylate with a single alkyl chain length of 13 or 17 carbon atoms. On the contrary, the average diameters of silver nanoparticles became large and polydisperse in the case of silver carboxylate with a chain length of 7 carbon atoms or a branched chain. In comparing triethylamine with trioctylamine, there was no obvious effect to regulate the size distribution of the nanoparticles because they could not function as a capping ligand of the nanoparticles due to their weak coordination to silver. In addition, the heat treatment of silver nanoparticles in solution rather than in the solid state was effective for the growth of particles while maintaining narrow size distributions. 相似文献
73.
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75.
G. M. Kalvius A. Kratzer K. -H. Münch T. Takabatake G. Nakamoto H. Fujii R. Wäppling H. -H. Klauß R. Kiefl S. Kreitzman D. R. Noakes 《Hyperfine Interactions》1994,85(1):411-417
Zero-, longitudinal and transverseSR measurements are reported on CeNiSn, CePdSn and CePtSn. Below 1 K CeNiSn exhibits strong magnetic correlations, up to possible short range order, but a magnetic phase transition did not occur down to 0.033 K. CePdSn and CePtSn signal their transition into the ordered antiferromagnetic phase by a spontaneous spin precession signal. The second magnetic phase transition in CePtSn reveals itself by the onset of a more complex spin precession pattern. Most unusual is the formation of a paramagnetic state with frozen random spin structure in CePtSn about one Kelvin aboveT
N.This work was supported by the German Federal Minister for Research and Technology (Bundesminister für Forschung und Technologie [BMFT]) under Contract Nr. 03KA2-TUM-4. 相似文献
76.
Takeshi Nakatani Tomohiro Matsushita Yutaka Miyatake Tomohito Nohno Atsushi Kobayashi Keiki Fukumoto Shunsuke Okamoto Azusa Nakamoto Fumihiko Matsui Ken Hattori Masato Kotsugi Yuji Saitoh Shigemasa Suga Hiroshi Daimon 《Progress in Surface Science》2003,71(5-8):217-239
A stereograph of atomic arrangement was displayed directly on the screen of display-type spherical-mirror analyzer without any computer-aided conversion process for the first time. This stereoscopic photograph enables viewing three-dimensional atomic arrangement. This technique was realized taking advantage of the phenomenon of circular dichroism in photoelectron angular distribution. The azimuthal shifts of forward focusing peaks in a photoelectron angular distribution taken with left and right helicity light in a special arrangement are the same as the parallaxes in a stereo view of atoms. Hence a stereoscopic recognition of three-dimensional atomic arrangement is possible, when the left eye and the right eye respectively view the two images obtained by left and right helicity light simultaneously. 相似文献
77.
Nakamoto M Fukawa T Lee VY Sekiguchi A 《Journal of the American Chemical Society》2002,124(51):15160-15161
Pale-yellow crystals of the nonsolvated monomeric silyl- and germyllithiums, tris[di-tert-butyl(methyl)silyl]silyllithium 2a and tris[di-tert-butyl(methyl)silyl]germyllithium 2b, were obtained by one-electron reduction of the corresponding silyl and germyl radicals with lithium in hexane. The crystal structure analysis of both 2a and 2b showed almost planar geometry around the anionic centers, due to both intramolecular CH-Li agostic interactions and steric reasons. However, the free anions [(tBu2MeSi)3Si-][Li+(THF)4] 3a and [(tBu2MeSi)3Ge-][Li+(THF)n] (n = 3, 4) 3b no longer showed a planar geometry, because of the absence of the intramolecular CH-Li agostic interaction. A temperature-dependent 1H NMR study of 2a showed that the CH-Li interaction is weak. 相似文献
78.
Sekiguchi A. Matsuo T. Tanaka M. Watanabe H. Nakamoto M. 《Russian Chemical Bulletin》2004,53(5):1109-1115
The reaction of tetrakis(trimethylsilyl)cyclobutadienylcyclopentadienyl cobalt complex (Me3Si)4C4CoCp with lithium metal in THF yielded the dilithium salt of cyclobutadiene dianion CBD2– stabilized by four trimethylsilyl groups, Li+
2[(Me3Si)4C4]2–. The bridged CBD2– dianion was also synthesized by a similar procedure starting from the bridged cobalt complex, which was prepared from the reaction of 2,2,5,5,8,8,11,11-octamethyl-2,5,8,11-tetrasilacyclododeca-1,6-diyne with CpCo(CO)2 in refluxing octane. The aromaticity of the CBD2– is discussed on the basis of the structural characteristics and magnetic properties. 相似文献
79.
A set of new delta(Se) parameters is proposed as a standard for the planar (pl) orientational effect of p-YC(6)H(4) (Ar) in ArSeR, employing 9-(arylselanyl)triptycenes (1: p-YC(6)H(4)SeTpc). The Se-C(R) bond in ArSeR is placed on the Ar plane in pl and it is perpendicular to the plane in pd. Large upfield shifts are observed for Y = NMe(2), OMe, and Me (-22 to -6 ppm) and large downfield shifts for Y = COOEt, CN, and NO(2) (19-37 ppm), relative to Y = H, with small upfield and moderate downfield shifts by Y of halogens (-1 ppm for Y = F and 4 ppm for Y = Cl and Br). This must be the result of the p(Se)-pi(C(6)H(4))-p(Y) conjugation in 1 (pl). While the character of delta(Se) in 1 (pl) is very similar to that in 9-(arylselanyl)anthracenes (2 (pl)), it is very different from that of 1-(arylselanyl)anthraquinones (3 (pd)). Sets of delta(Se) of 1 and 2 must serve as the standard for pl and that of 3 does for pd in solutions. Structures of various ArSeR in solutions are determined from the viewpoint of the orientational effect based on the standard delta(Se) of 1-3. While the structure of 2-methyl-1-(arylselanyl)naphthalenes is concluded to be all pl in solutions, those of 8-chloro- and 8-bromo-1-(arylselanyl)naphthalenes are all pd, except for Y = COOEt, CN, and NO(2): The equilibrium between pd and pl contributes to those with Y = COOEt, CN, and NO(2). The structure of 1-(arylselanyl)naphthalenes changes depending on Y. The structures of ArSeMe and ArSeCOPh are shown to be pl and pd, respectively, in solutions. Those of ArSePh and ArSeAr seem to change depending on Y. delta(Se) of 1-3 are demonstrated to serve as the standard to determine the structures in solutions. The rules of thumb derived from the characters in delta(Se) for 1-3 are very useful to determine the structures of ArSeR in solutions, in addition to the analysis based on the plots. 相似文献
80.
Miho Tanaka Yoko Hoshino Daisuke Nakamoto 《Rapid communications in mass spectrometry : RCM》2019,33(19):1527-1536