全文获取类型
收费全文 | 195篇 |
免费 | 22篇 |
国内免费 | 45篇 |
出版年
2024年 | 1篇 |
2023年 | 5篇 |
2022年 | 3篇 |
2021年 | 2篇 |
2020年 | 4篇 |
2019年 | 17篇 |
2018年 | 6篇 |
2017年 | 8篇 |
2016年 | 6篇 |
2015年 | 4篇 |
2014年 | 9篇 |
2013年 | 10篇 |
2012年 | 2篇 |
2011年 | 7篇 |
2010年 | 7篇 |
2009年 | 10篇 |
2008年 | 9篇 |
2007年 | 8篇 |
2006年 | 16篇 |
2005年 | 13篇 |
2004年 | 7篇 |
2003年 | 5篇 |
2002年 | 4篇 |
2001年 | 3篇 |
2000年 | 9篇 |
1999年 | 5篇 |
1998年 | 8篇 |
1997年 | 11篇 |
1996年 | 7篇 |
1995年 | 2篇 |
1994年 | 4篇 |
1993年 | 11篇 |
1992年 | 7篇 |
1991年 | 3篇 |
1990年 | 9篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1986年 | 5篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1980年 | 1篇 |
排序方式: 共有262条查询结果,搜索用时 4 毫秒
261.
Kenny Alexandra Rodriguez-Wallberg Max Waterstone Amandine Anastácio 《Reproductive biology》2019,19(2):119-126
Since the first reported birth following in vitro fertilization in 1978, further developments in assisted reproductive technology (ART) treatments have produced at least 8 million babies worldwide. Cryopreservation techniques have been central to this treatment revolution, increasing cycle efficacy by allowing the banking of supernumerary embryos for later use, as well as affording the prospective patient more time in cases of anticipated fertility decline. Additionally, these techniques have demonstrated promise in increasing the safety of ART treatments, by reducing complications such as ovarian hyperstimulation, leading to increased support for the introduction of a ‘total freeze’ policy involving deferred embryo transfers. Importantly, the effective cryopreservation of both spermatozoa and oocytes has permitted long-term gamete storage without degradation of quality, facilitating gamete banking for personal use or fertility treatment. Here, we will summarise the indications for applying cryopreservation methods in clinical reproductive medicine, highlighting recent technical advances and examining the evidence base that supports the continued use of cryopreservation in ART. 相似文献
262.
Hong Yu Wenwen Zi Shi Lan Shucai Gan Haifeng Zou Xuechun Xu Guangyan Hong 《Luminescence》2013,28(5):679-684
Sr3MgSi2O8:Ce3+, Dy3+ phosphors were prepared by a solid‐state reaction technique and the photoluminescence properties were investigated. The emission spectra show not only a band due to Ce3+ ions (403 nm) but also as a band due to Dy3+ ions (480, 575 nm) (UV light excitation). The photoluminescence properties reveal that effective energy transfer occurs in Ce3+/Dy3+ co‐doped Sr3MgSi2O8 phosphors, and the co‐doping of Ce3+ could enhance the emission intensity of Dy3+ to a certain extent by transferring its energy to Dy3+. The Ce3+/Dy3+ energy transfer was investigated by emission/excitation spectra, and photoluminescence decay behaviors. In Sr2.94MgSi2O8:0.01Ce3+, 0.05Dy3+ phosphors, the fluorescence lifetime of Dy3+ (from 3.35 to 27.59 ns) is increased whereas that of Ce3+ is greatly decreased (from 43.59 to 13.55 ns), and this provides indirect evidence of the Ce3+ to Dy3+ energy transfer. The varied emitted color of Sr3MgSi2O8:Ce3+, Dy3+ phosphors from blue to white were achieved by altering the concentration ratio of Ce3+ and Dy3+. These results indicate Sr3MgSi2O8:Ce3+, Dy3+ may be as a candidate phosphor for white light‐emitting diodes. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献