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81.
M. Adachi T. Kohno A. Makishima S. Fukuda M. Fukuda M. Taya H. Taketani 《Nuclear Physics A》1985,442(2):361-368
The g-factors of two isomeric states at Ex = 3763 and 5170 keV in 216Ra have been measured to be 0.51 ± 0.03 and 0.63 ± 0.06, respectively, with a TDPAD method. Spin and parity assignments of 19? for the 3763 keV state and 25? or 24+ for the 5170 keV state are consistent with the measured g-factors. Proposed configurations for the 19? and 25? assignments are of the same type as those predicted by a deformed independent-particle model for 214Rn, which is an isotone of 216Ra. 相似文献
82.
Kenji Mori Hiroko Nomi Tatsuji Chuman Masahiro Kohno Kunio Kato Masao Noguchi 《Tetrahedron letters》1981,22(12):1127-1130
The absolute configuration at C-6 and C-7 of serricornin was established as (6, 7) by synthesizing its (6, 7- and (6, 7- isomers. 相似文献
83.
Nishizawa M Kohno M Nishimura M Kitagawa A Niwano Y 《Chemical & pharmaceutical bulletin》2005,53(6):714-716
A stable radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) has long been used as a convenient method for the antioxidant assay of biological materials such as cysteine, glutathione, ascorbic acid, tocopherol and polyhydroxy aromatic compounds (hydroquinone, pyrogallol, etc.). In this study, non-reductive scavenging of DPPH was investigated by electron spin resonance (ESR) analyses for the purpose of developing a useful method for quantitative determination of peroxyradical. Since DPPH was degraded in the presence of peroxyradical derived from UV-irradiated benzoylperoxide and the peroxyradical-induced degradation of DPPH was inhibited by the addition of a spin trapping agent 5,5-dimethyl-1-pyrroline-N-oxide (DMPO), it is concluded that DPPH is non-reductively scavenged by peroxyradical. Therefore, it is suggested that DPPH could be a useful agent for the quantitative measurement of peroxyradical. 相似文献
84.
Ando K Tsuji E Ando Y Kunitomo J Yamashita M Ohta S Nabe T Kohno S Yokomizo T Shimizu T Ohishi Y 《Organic & biomolecular chemistry》2004,2(23):3427-3431
(E)-2-Acetyl-4-(2-diethylcarbamoyl-1-methylvinyl)-7-(1-phenylethoxy)benzo[b]furan (4b) with a characteristic conformation and (E)-2-(2-morpholinocarbo-1-methylvinyl)-7-ethoxycarbopropoxybenzo[b]furan ((E)-3b) were prepared and evaluated for their leukotriene B4(LTB4) antagonistic activity. Compound 4b showed potent antagonistic activity against human BLT1 and BLT2 receptors. Compound (E)-3b displayed selective BLT2 receptor antagonistic activity. Both compounds were inactive to cysteinyl LT receptors. 相似文献
85.
Murakami T Kohno K Ninomiya K Matsuda H Yoshikawa M 《Chemical & pharmaceutical bulletin》2001,49(8):1003-1008
A new ionone glucoside, pisumionoside, a phenethyl glycoside, sayaendoside, and two acylated flavonol oligoglycosides, pisumflavonosides I and II, were isolated from the young seedpods of garden peas, Pisum sativum L., together with quercetin and kaempferol 3-O-(6-O-trans-p-coumaroyl)-beta-D-glucopyranosyl (1-->2)-beta-D-glucopyranosyl (1-->2)-beta-D-glucopyranosides and quercetin and kaempferol 3-sophorotriosides. The structures of pisumionoside, sayaendoside, and pisumflavonosides I and II were determined on the basis of chemical and physicochemical evidence, respectively. Quercetin 3-sophorotrioside, a principle component, was found to show protective effects on liver injury induced by D-galactosamine and lipopolysaccharide and by carbon tetrachloride in mice. 相似文献
86.
N. Shinohara N. Kohno T. Suzuki S. Usuda 《Journal of Radioanalytical and Nuclear Chemistry》1989,130(1):3-12
A method for analyzing the content of237Np in spent fuel has been developed using inherent239Np as a chemical yield monitor. After ion-exchange separations for the dissolved fuel solution, the237Np content in the neptunium fraction was determined from the activity of237Np or of233Pa, which is in radioactive equilibrium with237Np. The chemical yield in the separations was determined both from the content of243Am which is in radioactive equilibrium with239Np before the separations and from the239Np content in the neptunium fraction after the separations by alpha- and gamma-ray spectrometry. 相似文献
87.
Radioactivity of the histamine-induced paw edema was measured after intravenous injection of 67Ga-citrate in anesthetized rats. The radioactivity was fluctuated almost parallel with the edema rate following subcutaneous injection of histamine. Both the radioactivity and the edema rate were almost equally reduced by pretreatment with chlorpheniramine, an antihistaminic agent. There was a good correlation between the edema rate and the radioactivity. These results suggest that 67Ga-citrate is useful for the pharmacological study of antiinflammatory drugs, or is available for measuring the vascular permeability. 相似文献
88.
Murakami T Kohno K Kishi A Matsuda H Yoshikawa M 《Chemical & pharmaceutical bulletin》2000,48(11):1673-1680
A new ent-kaurane-type glycoside, canavalioside, and eight new acylated flavonol glycosides, gladiatosides A1, A2, A3, B1, B2, B3, C1, and C2, were isolated from the seed of Canavalia gladiata together with robinin, kaempferol 3-O-beta-D-galactopyranosyl-7-O-alpha-L-rhamnopyranoside, and kaikasaponin III. The absolute stereostructures of canavalioside and gladiatosides A1, A2, B1, B2, B3, C1, and C2 were elucidated on the basis of chemical and physicochemical evidence. 相似文献
89.
Osamu Takahashi Katsuyoshi Yamasaki Yuji Kohno Kazuyoshi Ueda Hiroko Suezawa Motohiro Nishio 《化学:亚洲杂志》2006,1(6):852-859
Ab initio molecular‐orbital (MO) calculations were carried out, at the MP2/6‐311++G(d,p)//MP2/6‐31G(d) level, to investigate the conformational Gibbs energy of alkyl 1‐cyclohexylethyl ketones, cyclo‐C6H11CHCH3? CO? R (R=Me, Et, iPr, and tBu). In each case, one of the equatorial conformations was shown to be the most stable. Conformers with the axial CHCH3COR group were also shown to be present in an appreciable concentration. Short C? H???C?O and C? H???O?C distances were found in each stable conformation. The result was interpreted on the grounds of C? H???π(C?O) and C? H???O hydrogen bonds, which stabilize the geometry of the molecule. The ratio of the diastereomeric secondary alcohols produced in the nucleophilic addition to cyclo‐C6H11CHCH3? CO? R was estimated on the basis of the conformer distribution. The calculated result was consistent with the experimental data previously reported: the gradual increase in the product ratio (major/minor) along the series was followed by a drop at R=tBu. The energy of the diastereomeric transition states in the addition of LiH to cyclo‐C6H11CHCH3? CO? R was also calculated for R=Me and tBu. The product ratio did not differ significantly in going from R=Me to tBu in the case of the aliphatic ketones. This is compatible with the above result calculated on the basis of the conformer distribution. Thus, the mechanism of the π‐facial selection can be explained in terms of the simple premise that the geometry of the transition state resembles the ground‐state conformation of the substrates and that the nucleophilic reagent approaches from the less‐hindered side of the carbonyl π face. 相似文献
90.
Shinkichi Honda Ken-ichi Urakami Kohji Koura Kazunori Terada Yoshinobu Sato Kyoko Kohno Mitsuo Sekine Tsujiaki Hata 《Tetrahedron》1984,40(1):153-163
The fully protected ribonucleotide units (6a–d) have been synthesized in 42–62% overall yields by the 5- or 6-step reactions. The dimethoxtrityl, monomethoxytrityl, tetrahydropyran-2-yl, and phenylthio groups were introduced onto the 5'-OH, exo-amino, 2'-OH, and 3'-phosphoryl functions, respectively. The units were converted to the OH or phosphodiester components by treatment with trifluoroacetic acid or with phosphinic acid-triethylamine. Both the components were appropriately coupled by means of mesitylenedisulphonyl chloride 3-nitro-1,2,4-triazole to give dimers in high yields. This method was successfully applied to the synthesis of GpUpApUpUpApApUpAp, i.e. the 5'-terminal base sequence of brome mosaic virus m RNA No. 4 filament. 相似文献