全文获取类型
收费全文 | 176篇 |
免费 | 0篇 |
专业分类
化学 | 117篇 |
晶体学 | 2篇 |
数学 | 9篇 |
物理学 | 48篇 |
出版年
2020年 | 2篇 |
2019年 | 3篇 |
2018年 | 4篇 |
2017年 | 3篇 |
2016年 | 3篇 |
2014年 | 8篇 |
2013年 | 5篇 |
2012年 | 9篇 |
2011年 | 7篇 |
2010年 | 9篇 |
2009年 | 2篇 |
2008年 | 8篇 |
2007年 | 9篇 |
2006年 | 6篇 |
2005年 | 7篇 |
2004年 | 8篇 |
2003年 | 5篇 |
2002年 | 5篇 |
2001年 | 8篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 4篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1973年 | 4篇 |
1972年 | 5篇 |
1971年 | 3篇 |
1970年 | 2篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1967年 | 2篇 |
1965年 | 3篇 |
1964年 | 1篇 |
1959年 | 1篇 |
1958年 | 2篇 |
1955年 | 1篇 |
排序方式: 共有176条查询结果,搜索用时 406 毫秒
11.
The electrokinetic characteristics (the isoelectric point, electrokinetic potential, and surface conductivity) are studied as functions of pH against the background of NaCl solutions for the initial surfaces of silicon (covered with an oxide layer) and silicon oxide (a plane-parallel capillary of quartz glass and aerosil OX-50) and for the same surfaces after a preliminary thermal and chemical (CCl4 vapors at 400°C) treatment. The position of the isoelectric point for the systems in question is shown to be primarily affected by the preliminary annealing, which shifts this point toward higher pH. The electrokinetic behavior of silicon plates covered with an oxide film is compared to the electrode behavior of a similar board of an ion-selective field-effect transistor. 相似文献
12.
A one-step procedure was developed for the synthesis of new 6-fluoro-7-(isoxazolidin-2-yl)-4-oxo-1,4-dihydroquinolines. The procedure is based on the 1,3-dipolar cycloaddition of the azomethine oxide and 1,1-disubstituted alkenes, which are generated in situ from 6-fluoro-7-hydroxylamino-4-oxo-1,4-dihydroquinoline-3-carboxylic acid and CH-active compounds (dialkyl malonates, ethyl acetoacetate), respectively, in the presence of formaldehyde at 100—120 °C. 相似文献
13.
A. Z. Abyshev I. P. Sidorova D. Z. Abyshev V. N. Florya V. P. Zmeikov Yu. B. Kerimov 《Chemistry of Natural Compounds》1982,18(4):400-407
The results are given of the identification of (?)-trans-khellactone and its 4′-methyl ether and (?)-3′(S), 4′(S)-trans-3′-senecioyloxy-4′-angeloyloxy-3′,4′-dihydroseselin and of the establishment of the structure of three new khellactone derivatives — campestrol (VII), C19H22O6, [α] D 20 + 32° (c 7.8; chloroform), campestrinol (X), C24H26O7, mp 116–118°C, and campestrinoside (I), C20H24O10, mp 172–173°C, [α]D ?272.5° (c 4.7; ethanol). It has been shown on the basis of chemical and spectral characteristics that campesol, earlier described as a new substance, is a mixture of two isomeric compounds — 4′-hydroxy-3′-senecioyloxy-3′,4′-dihydroseselin and 3′-angeloyloxy-4′-hydroxy-3′,4′-dihydroseselin. 相似文献
14.
I. I. Popov N. S. Vashurin S. E. Putilin S. A. Stepanov V. T. Sidorova N. I. Sushentsov 《Bulletin of the Russian Academy of Sciences: Physics》2014,78(2):152-155
A femtosecond stimulated photon echo is detected for the first time in thin semiconductor films with thicknesses of 100, 800, and 2400 nm. It is established that relaxation time T 1 varies with ZnO film thickness, taking values of 0.96, 2.96, and 4.312 ps at thicknesses of 2400, 800, and 100 nm, respectively. For ZnO/Si+/Si? trilayer films, the relaxation time is T 1 = 12.73 ps. 相似文献
15.
M. N. Efimov A. A. Nekrasova E. L. Dzidziguri E. N. Sidorova L. M. Zemtsov G. P. Karpacheva 《Crystallography Reports》2012,57(4):569-573
The structure of nanocomposites of the C-Pd system has been studied by X-ray diffraction analysis and transmission electron microscopy. Variations in the lattice period of nanosized palladium, the average amount of hydrogen dissolved in it, and the size distribution of palladium nanoparticles have been analyzed as functions of the nanocomposite fabrication temperature. Based on the structural data, the solubility of hydrogen in nanosized palladium has been estimated. 相似文献
16.
V. S. Alexandrov E. E. Donets G. I. Konnov V. V. Kosukhin V. O. Sidorova A. I. Sidorov V. S. Shvetsov G. V. Trubnikov 《Physics of Particles and Nuclei Letters》2014,11(5):656-659
A high-voltage platform that has been developed for the KRION ion source is described. The platform design concept is explained. The calculations that have been performed of the influence of the design and materials on the source magnetic field make it possible to define a range of materials suitable for manufacturing the platform. The major components of the high-voltage platform, such as a high-voltage power supplier, and decoupling insulators of the high-voltage power source, and the main and supplementary platforms, are chosen and described. It is determined that, to exclude electric breakdowns and corona discharges, one should use an electrically shielded channel with a cryocooler and power supplies for the KRION-source coupling cables. 相似文献
17.
Dmitry V. Yaroshenko Alexander V. Grigoriev Alla A. Sidorova 《Analytical and bioanalytical chemistry》2014,406(3):923-927
A reliable and high throughput high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed and validated for determining levels of the antitubercular drug-d -cycloserine in human plasma. Plasma samples analyte with an internal standard (IS) (niacin) were prepared by solid-phase extraction using Waters Oasis MCX cartridges. The chromatographic separation was performed using the HILIC mode on a YMC-Pack SIL-06 column (150?×?4.6 mm; 3 μm) under isocratic conditions. The run time of analysis was 5 min. The mobile phase consisted of methanol, propanol-2 and 0.075 % trifluoroacetic acid (66.5:28.5:5, v/v/v). Protonated ions formed by turbo ion spray in positive mode were used to detect the analyte and the IS. MS/MS detection was used to monitor the fragmentation of 103–75?m/z for cycloserine and 124 to 80?m/z for niacin (IS) on an API 4000 (AB Sciex) triple quadrupole mass spectrometer. A linear dynamic range of 0.3–30 μg/mL was established for cycloserine using 0.2 mL human plasma and a 1 μL injection volume. The mean relative recovery of cycloserine and niacin were 77.2 and 82.4 %, respectively. The procedure of sample preparation was consistent and reproducible (precision, 0.8–3.4 %; accuracy, 93.8–104.9 %). The method was validated in accordance with requirements of the European Medicines Agency and successfully applied to a bioequivalence study of 250 mg tablet formulations in 23 healthy human subjects. 相似文献
18.
I. S. Yaroshenko A. Ya. Khaimenov A. V. Grigoriev A. A. Sidorova 《Journal of Analytical Chemistry》2014,69(8):793-799
A method is proposed for determining rhein (an active metabolite of diacerein) in human blood plasma by reversed-phase high-performance liquid chromatography with UV detection. The analyte was selectively extracted from blood plasma by liquid-liquid extraction with a 5% solution of tert-butyl methyl ether in ethyl acetate. The recovery of rhein is 68 ± 3%, LOQ 100 ng/mL. The stability of the analytes and linearity, selectivity, sensitivity, reproducibility, and accuracy of the developed method are evaluated. The pharmacokinetics of diacerein in the oral administration of drug formulations by 18 healthy volunteers is studied. 相似文献
19.
20.