全文获取类型
收费全文 | 195篇 |
免费 | 3篇 |
专业分类
化学 | 100篇 |
晶体学 | 3篇 |
力学 | 2篇 |
数学 | 79篇 |
物理学 | 14篇 |
出版年
2023年 | 1篇 |
2022年 | 3篇 |
2021年 | 6篇 |
2020年 | 3篇 |
2019年 | 6篇 |
2018年 | 8篇 |
2017年 | 5篇 |
2016年 | 3篇 |
2015年 | 6篇 |
2014年 | 11篇 |
2013年 | 16篇 |
2012年 | 10篇 |
2011年 | 16篇 |
2010年 | 13篇 |
2009年 | 12篇 |
2008年 | 10篇 |
2007年 | 5篇 |
2006年 | 6篇 |
2005年 | 7篇 |
2004年 | 7篇 |
2003年 | 5篇 |
2002年 | 8篇 |
2001年 | 6篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1996年 | 1篇 |
1992年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 3篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1971年 | 1篇 |
1960年 | 3篇 |
1958年 | 1篇 |
排序方式: 共有198条查询结果,搜索用时 0 毫秒
41.
Razvan Stefan Petru Pascuta Adriana Popa Oana Raita Emil Indrea Eugen Culea 《Journal of Physics and Chemistry of Solids》2012,73(2):221-226
Glasses in the system xFe2O3·(100?x) [45ZnO·55B2O3] (0≤x≤10 mol%) have been prepared by melting at 1200 °C and rapidly cooling at room temperature. The obtained samples were submitted to an additional thermal treatment at 570 °C for 12 h in order to relax the glass structure as well as to improve the local order. The as cast and heat treated samples were investigated using X-ray diffraction (XRD) and electron paramagnetic resonance (EPR) measurements. The XRD patterns of all the studied samples show their vitreous nature. Structural modifications occurring in the heat treated samples compared to the untreated ones have been pointed out. EPR spectra of untreated and heat treated samples revealed resonance absorptions centered at g≈2.0, g≈4.3 and g≈6.4. The compositional variation of the line intensity and linewidth of the absorptions from g≈4.3 and g≈2.0 have been interpreted in terms of the variation in the concentration of the Fe3+ ions and the interaction between the iron ions. The EPR spectra of the untreated samples containing 5 mol% Fe2O3 have been studied at different temperatures (110–290 K). The line intensity of the resonance signals decreases with increase in temperature whereas the linewidth is found to be independent of temperature. It was also found that the temperature variation of reciprocal line intensity obeys the Boltzmann law. 相似文献
42.
43.
Metodija Najdoski Radmila Aleksovska Vladimir M. Petruševski 《The Chemical Educator》2001,6(6):319-320
A chemical wave was initiated in a system (glass tube or graduated cylinder) containing a water solution of potassium iodate, potassium hydrogen sulfate, starch, and an excess of potassium arsenite. A large number of photos (329) were taken with a digital camera (one snapshot every 30 seconds). These photos were linked to give a unique video clip. This video clip may be used as a time-saving alternative to the classical demonstration. Similar clips may be made for other long-lasting processes. 相似文献
44.
Gabriela Kohr Petru T. Mocanu 《Journal of Mathematical Analysis and Applications》2007,332(1):463-474
In this paper we consider convex subordination chains (c.s.c.) and alpha-prestarlike subordination chains (α-p.s.c.) over (0,1] on the unit disc in the complex plane. We obtain sufficient conditions for a mapping f(z,t) to be an α-p.s.c. over (0,1], which generalize a well-known result of Ruscheweyh [St. Ruscheweyh, Convolutions in Geometric Function Theory, Les Presses de l'Université de Montreal, 1982]. We also obtain sufficient conditions for injectivity for nonanalytic mappings on the unit disc, and give certain examples of α-c.s.c. over (0,1] on the unit disc. 相似文献
45.
We study properties concerning approximation of fuzzy-number-valued functions by fuzzy B-spline series. Error bounds in approximation by fuzzy B-spine series are obtained in terms of the modulus of continuity. Particularly simple error bounds are obtained for fuzzy splines of Schoenberg type. We compare fuzzy B-spline series with existing fuzzy concepts of splines. 相似文献
46.
K. Prokeš A. Burian L. Judas P. Kasík R. Keclík B. Konopásek L. Petruželka 《Journal of Radioanalytical and Nuclear Chemistry》1988,127(1):1-5
Miniature silicon photodiodes have been tested for utilization in radiotherapy. Their use in the treatment of ca laryngis is described. The actually given dose was monitored during irradiation. Treatment plan or the setting up of the entrance fields was modified according to the response of the diode. This method seems to be a useful tool for checking both the treatment plan and appropriate setting up of the patient in treatment position. 相似文献
47.
Ledeti Ionut Pusztai Agneta Maria Murariu Marius Olariu Sorin Ivan Codrut Circioban Denisa Vlase Gabriela Ledeti Adriana Vlase Titus Matusz Petru 《Journal of Thermal Analysis and Calorimetry》2018,131(2):1345-1360
Journal of Thermal Analysis and Calorimetry - In this work, solifenacin succinate (SOLS), flavoxate HCl (FLXHC) and tolterodine tartrate (TOLT) drugs were investigated using thermal analysis (TA)... 相似文献
48.
49.
In this paper, a TG/DTG–DSC–FTIR study of type I collagen extracted from bovine Achilles tendon both in inert (nitrogen) and oxidative atmosphere (synthetic air and oxygen) from room temperature to 700 °C was performed. The thermal analysis results have shown that after initial dehydration, collagen exhibits a single decomposition step in nitrogen (due to pyrolysis), while in air and oxygen two steps are observed due to thermo-oxidative decomposition, the latter being highly exothermic. The CO2 bands dominate the FTIR spectra of evolved gases in all atmospheres (especially in air and oxygen), along with the characteristic bands of ammonia, water, HNCO, methane. In nitrogen, the bands of pyrrole, HCN, and ethane were also identified, while in oxidative atmospheres, nitrogen oxides and CO are released. A study was also performed by comparing the DTG and gas evolution curves observed for the three atmospheres. 相似文献
50.