全文获取类型
| 收费全文 | 318篇 |
| 免费 | 1篇 |
| 国内免费 | 1篇 |
专业分类
| 化学 | 127篇 |
| 力学 | 11篇 |
| 数学 | 84篇 |
| 物理学 | 98篇 |
出版年
| 2024年 | 2篇 |
| 2022年 | 4篇 |
| 2021年 | 5篇 |
| 2020年 | 8篇 |
| 2019年 | 8篇 |
| 2018年 | 6篇 |
| 2017年 | 5篇 |
| 2016年 | 18篇 |
| 2015年 | 12篇 |
| 2014年 | 7篇 |
| 2013年 | 43篇 |
| 2012年 | 11篇 |
| 2011年 | 18篇 |
| 2010年 | 7篇 |
| 2009年 | 7篇 |
| 2008年 | 9篇 |
| 2007年 | 12篇 |
| 2006年 | 14篇 |
| 2005年 | 9篇 |
| 2004年 | 9篇 |
| 2003年 | 4篇 |
| 2001年 | 2篇 |
| 2000年 | 2篇 |
| 1999年 | 6篇 |
| 1998年 | 2篇 |
| 1997年 | 6篇 |
| 1996年 | 3篇 |
| 1994年 | 3篇 |
| 1993年 | 2篇 |
| 1992年 | 4篇 |
| 1990年 | 3篇 |
| 1989年 | 3篇 |
| 1988年 | 2篇 |
| 1985年 | 3篇 |
| 1984年 | 8篇 |
| 1983年 | 5篇 |
| 1982年 | 4篇 |
| 1981年 | 4篇 |
| 1978年 | 2篇 |
| 1977年 | 3篇 |
| 1975年 | 3篇 |
| 1974年 | 2篇 |
| 1972年 | 3篇 |
| 1965年 | 2篇 |
| 1943年 | 2篇 |
| 1940年 | 2篇 |
| 1933年 | 2篇 |
| 1918年 | 2篇 |
| 1898年 | 1篇 |
| 1893年 | 1篇 |
排序方式： 共有320条查询结果，搜索用时 0 毫秒
101.
Yaşar Dürüst 《Phosphorus, sulfur, and silicon and the related elements》2013,188(11):2923-2935
Synthesis and spectral characterization of novel 1,3,4-thiadiazole derivatives including one organo-mercury compound are described. Their structure elucidation was performed by means of spectroscopic and physical methods (IR, 1H NMR, 13C NMR, MS, X-ray). 相似文献
102.
L. Reeve T. Swinden W. W. Stevenson G. E. Speight H. A. Sloman F. Willems N. Gray M. C. Sanders S. N. Schkotowa H. Kempf K. Abresch G. J. Weinberg R. Stumper P. Mettelock F. Wüst J. Duhr P. Klinger W. Koch H. Schottky H. Hiltenkamp H. J. Wiester I. Wada und R. Ishii 《Fresenius' Journal of Analytical Chemistry》1943,126(10):385-390
Ohne Zusammenfassung 相似文献
103.
J. Houben Julius Meyer F. P. Treadwell F. Heeren H. G. Martin Cl. E. Williams Arvid E. Anderson C. E. Sims B. M. Larsen E. Terres A. Pongracz H. C. M. Ingeberg F. Foerster V. Herold E. S. Peck G. Frerichs V. Coblentz O. B. May Edgar Thompson Steel Works A. D. Horlück A. Eberhard E. Schmidt Fr. Wüst N. Kirpach L. Schneider J. Parry J. J. Morgan und E. Diepschlag 《Fresenius' Journal of Analytical Chemistry》1927,71(8):297-311
Ohne Zusammenfassung 相似文献
104.
Following the recent observation that the Ricci flow and the infinite distance swampland conjecture are closely related to each other, we will investigate in this paper geometric flow equations for AdS space-time geometries. First, we consider the so called Yamabe and Ricci-Bourguignon flows and we show that these two flows - in contrast to the Ricci flow - lead to infinite distance fixed points for product spaces like , where denotes d-dimensional AdS space and corresponds to a p-dimensional sphere. Second, we consider black hole geometries in AdS space time geometries and their behaviour under the Yamabe and Ricci-Bourguignon flows. Specifically we will examine if and how the AdS black holes will undergo a Hawking-Page phase transition under the Ricci flow, the Yamabe flow and under the general Ricci-Bourguignon flow. 相似文献
105.
Raoul R. Nigmatulin Alexander P. Alekhin Dumitru Baleanu Erdal Dinç Zafer Üstündağ Haslet Ekşi Ali Osman Solak 《Electroanalysis》2010,22(4):419-426
The effect of the potential cycles on the reflective IR signals of nitro‐groups in nanofilms was studied for the statistical characterization of nitrobenzene (NB) and nitroazobenzene (NAB)‐modified glassy carbon (GC) surfaces. Both NB and NAB nanofilms were obtained by the electrochemical reduction of the diazonium tetrafluoroborate salts in acetonitrile using cyclic voltammetry (CV). The modified surfaces were denoted as GC‐(NB)n and GC‐(NAB)n, respectively, where n indicates the number of CV cycles performed during modification. Reflective IR signals of the normalized NB and NAB nanofilms and GC were used for the quantitative evaluation of the effect of the potential cycles on the reflective IR signals of nitro‐groups in nanofilms. The detection and quantitative ‘reading’ of the influence of number of CV cycles were realized in the frame of a new error controllable approach that was applied for analysis of all available set of data. This approach includes in itself the following basic steps: (a) the procedure of the division (normalization) on the GC spectra, (b) the comparison of the smoothed spectra for their statistical proximity in the frame of the statistics of the fractional moments, (c) extraction of possible calibration parameters for possible calibration of the normalized spectra with respect to the number of CV cycles. These three basic steps are becoming effective for detection of the influence of some external factors. In our case it is important to detect the influence of the factor n characterizing CV cycles. 相似文献
106.
107.
Aytekin Köse Özlem Gündoğdu Derya Aktaş Meryem Fıstıkçı Ramazan Altundaş Hasan Seçen Yunus Kara 《Helvetica chimica acta》2015,98(2):260-266
Starting from (S)‐serine, a new method was developed for the synthesis of the β‐amino acid part of sitagliptin in ten steps and with an overall yield of 30%. The crucial step of the synthesis was the ring opening of N‐ and O‐protected (R)‐aziridin‐2‐methanol with (2,4,5‐trifluorophenyl)magnesium bromide to give N‐ and O‐protected (R)‐2‐amino‐3‐(2,4,5‐trifluorophenyl)propan‐1‐ol. 相似文献
108.
İlknur Üstündağ Aslı Erkal Tamer Koralay Yusuf Kağan Kadıoğlu Seungwon Jeon 《Journal of Analytical Chemistry》2016,71(7):685-695
We obtained a gold nanomaterial/graphene oxide-modified glassy carbon electrode and characterized it using transmission electron microscope, scanning electron microscope, cyclic voltammetry (CV), and X-ray photoelectron spectroscopy techniques. A response of the electrode using square wave anodic stripping voltammetry for Pb2+, Cu2+, and Hg2+ was found linear in the range from 1 × 10–7 to 1 × 10–11 M. The detection limits of Pb2+, Cu2+ and Hg2+ were 0.14, 0.5 and 1.2 pM, respectively. The method was applied to the simultaneous determination of Pb2+, Cu2+ and Hg2+ in seawater samples from a coastal region of Anatolia, and the results corresponded well with the values obtained by inductively coupled plasma-optical emission spectroscopy. 相似文献
109.
Microwave-assisted 1,3-dipolar cycloaddition of 5-azidomethyl 3-aryl-substituted 1,2,4-oxadiazoles to electron-deficient alkyne; phenyl propiolic acid affords a series of 1,2,3-triazole derivatives carrying 3-p-substitutedphenyl-1,2,4-oxadiazolyl methyl unit. The structures of all the cycloadducts were elucidated by IR, NMR (1H, 13C, 2D), MASS (low and high resolution) spectra, X-ray diffraction data, and physical characteristics (melting points and Rf values). 相似文献
110.