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排序方式: 共有148条查询结果,搜索用时 15 毫秒
1.
Yasushi Seike Ryoko Fukumori Yukiko Senga Hiroki Oka Kaoru Fujinaga Minoru Okumura 《Analytical sciences》2004,20(1):139-142
A new and simple method for the determination of hydroxylamine in environmental water, such as fresh rivers and lakes using hypochlorite, followed by its gas choromatographic detection, has been developed. A glass vial filled with sample water was sealed by a butyl-rubber stopper and aluminum cap without head-space, and then sodium hypochlorite solution was injected into the vial through a syringe to convert hydroxylamine to nitrous oxide. The head-space in the glass vial was prepared with 99.9% grade N2 using a gas-tight syringe. After the glass vial was shaken for a few minutes, nitrous oxide in the gas-phase was measured by a gas chromatograph with an electron-capture detector. The dissolved nitrous oxide in the liquid-phase was calculated according to the solubility formula. The proposed method was applied to the analysis of fresh-water samples taken from Iu river and Hii river, flowing into brackish Lakes Nakaumi and Shinji, respectively. 相似文献
2.
Ryoko Chiba Ayako Ogasawara Teppei Kubo Hiroyuki Yamazaki Masuo Umino Yoichi Ishizuka 《Analytical sciences》2003,19(5):785-789
A column-switching high-performance liquid chromatographic method with fluorescence detection was developed for the simultaneous determination of four benzamide-type anti-psychotic drugs: sulpiride, tiapride, sultopride and metoclopramide in human serum. In this method, a TSKgel Super-ODS column was used as an analytical column, and a TSKgel G 2000SW was prepared as a pretreatment column. Under the optimized analytical conditions, four benzamide-type anti-psychotic drugs were eluted within 18 min. The detection limits (S/N = 3) for sulpiride, tiapride, sultopride and metoclopramide are 1 ng/ml, 4 ng/ml, 2 ng/ml and 0.5 ng/ml, respectively. Finally, the method was applied to the determination of sulpiride in human serum samples obtained after a single oral dose of sulpiride. 相似文献
3.
The surface electromigration (SE) of ultrathin In films on Si(111)4 × 1-In surfaces has been investigated using experimental techniques based on μ-electron beams. On the basis of the finding that the SE velocity enhances as the strength of the electrostatic field (EF) fed through the substrate enhances, it is strongly suggested that the driving force of SE is an EF rather than a DC current fed through the substrate. It is found that a patch of ultrathin In film changes to an In patch of 1 × 1 periodicity during SE which is accompanied by spotty parts (named fine-polygons) at both the cathode and anode sides of the In patch. It is found that the fine-polygons are created at the cathode side and are stationary but grow in size to be eventually incorporated into the In-patch. A few In-islands are found on the cathode side of the In-patch and they show no translation but cycles of appearance, growth, decay, and disappearance during SE, by which mass-transportation is achieved. A plausible microscopic model for the SE is presented based on these findings. 相似文献
4.
Tosinobu Anno 《Theoretical chemistry accounts》1972,25(3):248-253
The method of evaluation of the valence-state energy from the observed term values, as proposed originally by Moffitt [1] for unhybridized valence state and extended by Öpik [3] to the hybridized one, is critically reviewed. It is shown for the hybridized valence states that off-diagonal terms, corresponding to interactions among multiplets of the same symmetry arising from different configurations participating in the hybridized valence state, must also be considered in addition to the diagonal terms considered in Öpik's method. Actual procedure of doing this is given. A numerical example given shows that the improvement of Öpik's method proposed here may be ignored in a crude theory but is worth considering in order that the accurate value of the valence-state energy be obtained.
Zusammenfassung Das Verfahren zur Berechnung der Energie von Valenzzuständen, wie es von Öpik für den Fall hybridizierter Orbitale erweitert wurde, wird bezüglich der Behandlung von Nichtdiagonalelementen kritisiert. Es wird gezeigt, daß solche Terme, die der Wechselwirkung von Multipletts gleicher Symmetrie, aber verschiedener Konfiguration entsprechen, nur bei verhältnismäßig groben Rechnungen vernachlässigt werden dürfen. Anhand eines Beispiels wird gezeigt, daß sie bei größeren Ansprüchen an die Genauigkeit eingeschlossen werden sollten.相似文献
5.
Kazutoshi Shindo Ryoko NakamuraIkuko Chinda Yasuo OhnishiSueharu Horinouchi Haruko TakahashiKazuo Iguchi Shigeaki HarayamaKensuke Furukawa Norihiko Misawa 《Tetrahedron》2003,59(11):1895-1900
The bphA1(2072)A2A3A4 gene cluster codes for a shuffled biphenyl dioxygenase holoenzyme with broad substrate specificity. These bphA1(2072)A2A3A4 genes were expressed in the actinomycetes Streptomyces lividans using a thiostrepton-inducible promoter PtipA. Biotransformation experiments of various aromatics including carboxylic acid or amine in their molecular structure, such as 1-naphthoic acid, 2-(1-naphthyl)acetic acid, diphenylamine, and 1-benzyl-4-piperidone, were performed using the recombinant S. lividans cells. These ionized aromatics were converted to the corresponding 1,2-dihydrodiol, mono- or tri-hydroxy forms in 48 h. The structure of the converted products was determined by their EI-MS, 1H- and 13C NMR analysis, and several products were found to be novel compounds. 相似文献
6.
7.
Takeshi Hanamoto Yuhko Iwamoto Kenji Yamada Ryoko Anno 《Journal of fluorine chemistry》2007,128(10):1126-1130
The 1,3-dipolar cycloaddition reaction of fluoro(trimethylsilyl)acetylene prepared in situ with an excess of diazomethane smoothly proceeded to give the corresponding 4-fluoro-5-trimethylsilyl-1H-pyrazole in 84% yield. The copper iodide-catalyzed N-arylation of the fluorinated pyrazole with a variety of aryl iodides afforded N-aryl-4-fluoropyrazoles as desilylation products in good to excellent yields. 相似文献
8.
Minato M Sekimizu R Uchida D Ito T 《Dalton transactions (Cambridge, England : 2003)》2004,(21):3695-3698
Treatment of eta(3)-allyl compound [Cp(2)Mo(eta(3)-C(3)H(5))](+)(1; Cp =eta(5)-C(5)H(5)) with MH (M = Li, Na) resulted in reduction of the allyl ligand to give propane. Deuterium-labeling studies were used to trace the origins and fates of the hydrogen atoms. The mechanism is discussed in light of the HSAB principle. The studies showed that the formation of propane can be explained by 1,2-hydrogen migration from the central to the terminal carbon of the allyl ligand, and the subsequent double nucleophilic addition of the hydride at the central carbon. 相似文献
9.
Ogata M Kaneya D Shin-Ya K Li L Abe Y Katoh H Seki S Seki Y Gonda R Urano S Endo T 《Chemical & pharmaceutical bulletin》2005,53(9):1167-1170
Many researchers have stated that eugenol might inhibit lipid peroxidation at the stage of initiation, propagation, or both, and many attempts have been made to elucidate the mechanism of its antioxidant activity. Nevertheless, details of its mechanism are still obscure. This study was carried out to investigate the trapping effect of eugenol on hydroxyl radical generated from L-3,4-dihydroxyphenylalanine (DOPA) in MiliQ water and the generation mechanism of the hydroxyl radical by this system which uses no metallic factor. This was studied by adding L-DOPA and 5,5-dimethyl-1-pyrroline N-oxide (DMPO) to phosphate buffered saline (PBS) or MiliQ water, and the generation of hydroxyl radical was detected on an ESR spectrum. By this method, the effect of antioxidants was detected as a modification of ESR spectra. We found that the eugenol trapped hydroxyl radicals directly, because it had no iron chelating action, did not trap L-DOPA semiquinone radical and inhibited hydroxyl radicals with or without iron ion. 相似文献
10.
Keiichi Kimura Ryoko Mizutani Tatsuya Suzuki Masaaki Yokohama 《Journal of inclusion phenomena and macrocyclic chemistry》1998,32(2-3):295-310
Design of two types of ion-conducting systems using photochromic crown ethers as the photocontrol agents is described; one type is based on the phase transition of azobenzene derivatives induced by their photoisomerization and the other based on the molecular control of metal ion complexation by crowned spirobenzopyrans. The photoresponsive ion-conducting systems are applicable to electrostatic imaging and photorefractive materials. 相似文献