全文获取类型
收费全文 | 832篇 |
免费 | 23篇 |
专业分类
化学 | 641篇 |
晶体学 | 10篇 |
力学 | 22篇 |
数学 | 114篇 |
物理学 | 68篇 |
出版年
2023年 | 4篇 |
2022年 | 23篇 |
2021年 | 30篇 |
2020年 | 16篇 |
2019年 | 16篇 |
2018年 | 15篇 |
2017年 | 11篇 |
2016年 | 29篇 |
2015年 | 17篇 |
2014年 | 21篇 |
2013年 | 38篇 |
2012年 | 47篇 |
2011年 | 43篇 |
2010年 | 31篇 |
2009年 | 40篇 |
2008年 | 50篇 |
2007年 | 46篇 |
2006年 | 50篇 |
2005年 | 45篇 |
2004年 | 33篇 |
2003年 | 38篇 |
2002年 | 29篇 |
2001年 | 24篇 |
2000年 | 10篇 |
1999年 | 14篇 |
1998年 | 11篇 |
1997年 | 7篇 |
1996年 | 21篇 |
1995年 | 9篇 |
1994年 | 9篇 |
1993年 | 8篇 |
1992年 | 4篇 |
1991年 | 6篇 |
1990年 | 5篇 |
1989年 | 10篇 |
1988年 | 6篇 |
1987年 | 4篇 |
1986年 | 5篇 |
1985年 | 4篇 |
1984年 | 7篇 |
1983年 | 4篇 |
1982年 | 2篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1976年 | 3篇 |
1971年 | 1篇 |
排序方式: 共有855条查询结果,搜索用时 109 毫秒
851.
Gaetano Giammona Giovanna Pitarresi Gennara Cavallaro Giuseppe Spadaro 《Macromolecular Symposia》1999,138(1):225-230
α,β-Poly(N-2-hydroxyethyl)-DL-aspartamide (PHEA) was derivatized with glycidyl methacrylate (GMA). Aqueous solutions of the obtained copolymer PHEA-GMA (PHG) were irradiated by gamma rays with a dose rate of 0.5 KGy/h and at zero°C in the presence or in the absence of N, N'-methylenebisacrylamide (BIS). New hydrogel systems were obtained and characterized by FT-IR analyses and swelling measurements in aqueous medium at different pH values. 相似文献
852.
Giacomo Facchin Mario Gleria Francesco Minto Roberta Bertani Massimo Guglielmi Giovanna Brusatin 《Macromolecular rapid communications》1995,16(3):211-217
In this paper we describe a method for the functionalization of catenapoly[bis(4-hydroxyphenoxy)-λ5-phosphazene] with diazonium salts to form new, deeply-coloured, phosphazene copolymers containing variable amounts of azo dyes attached to the polyphosphazene skeleton. The degree of functionalization in these substrates is regulated in order not to exceed 20% of the sites available in the pristine polyphosphazene and to maintain a high percentage of unreacted, free, hydroxy groups, in the final, coloured copolymers. These species are still very reactive and able to undergo further functionalization reactions. 相似文献
853.
Paolo Vacca Maria Grazia Maglione Carla Minarini Giovanna Salzillo Eugenio Amendola Dario Della Sala Alfredo Rubino 《Macromolecular Symposia》2005,228(1):263-272
In order to optimize polymer light emitting diode (PLED) performances, devices with holes injected through an Indium Tin Oxide (ITO) / Polyaniline (PANI) electrode into the polymer are much more efficient than devices fabricated with the anode made only by ITO. We demonstrated that by using doped PANI as hole injection layer in a polymer light emitting diode the manufacturing process can become simpler. Indeed, the pattern of conductive layer can be produced without ITO photolithography by UV exposition. As hole transporter layer, Poly(N-vinylcarbazole) (PVK) was spin coated over the doped PANI layer and a layer of tris (8-hydroxy) quinoline aluminum (Alq3) was then thermally evaporated so as to form the electron transport layer. To complete the device structure, Aluminum contacts were deposited onto the organic layers by vacuum evaporation at low pressure. The layers were characterized by X-ray small-angle diffraction, IR Raman and UV-Vis spectroscopies. Devices without PANI and with PANI as HIL were studied. 相似文献
854.
855.