全文获取类型
收费全文 | 940篇 |
免费 | 140篇 |
国内免费 | 45篇 |
专业分类
化学 | 183篇 |
力学 | 56篇 |
综合类 | 3篇 |
数学 | 26篇 |
物理学 | 270篇 |
无线电 | 587篇 |
出版年
2024年 | 4篇 |
2023年 | 13篇 |
2022年 | 11篇 |
2021年 | 18篇 |
2020年 | 26篇 |
2019年 | 13篇 |
2018年 | 12篇 |
2017年 | 23篇 |
2016年 | 48篇 |
2015年 | 40篇 |
2014年 | 95篇 |
2013年 | 83篇 |
2012年 | 60篇 |
2011年 | 93篇 |
2010年 | 78篇 |
2009年 | 74篇 |
2008年 | 72篇 |
2007年 | 62篇 |
2006年 | 76篇 |
2005年 | 50篇 |
2004年 | 26篇 |
2003年 | 25篇 |
2002年 | 34篇 |
2001年 | 20篇 |
2000年 | 10篇 |
1999年 | 13篇 |
1998年 | 12篇 |
1997年 | 5篇 |
1996年 | 9篇 |
1995年 | 4篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1988年 | 3篇 |
排序方式: 共有1125条查询结果,搜索用时 31 毫秒
861.
Dr. Wolfgang Jahnke Dr. Guido Bold Dr. Andreas L. Marzinzik Dr. Silvio Ofner Xavier Pellé Dr. Simona Cotesta Emmanuelle Bourgier Sylvie Lehmann Chrystelle Henry René Hemmig Dr. Frédéric Stauffer Dr. J. Constanze D. Hartwieg Dr. Jonathan R. Green Dr. Jean‐Michel Rondeau 《Angewandte Chemie (International ed. in English)》2015,54(48):14575-14579
Targeting drugs to their desired site of action can increase their safety and efficacy. Bisphosphonates are prototypical examples of drugs targeted to bone. However, bisphosphonate bone affinity is often considered too strong and cannot be significantly modulated without losing activity on the enzymatic target, farnesyl pyrophosphate synthase (FPPS). Furthermore, bisphosphonate bone affinity comes at the expense of very low and variable oral bioavailability. FPPS inhibitors were developed with a monophosphonate as a bone‐affinity tag that confers moderate affinity to bone, which can furthermore be tuned to the desired level, and the relationship between structure and bone affinity was evaluated by using an NMR‐based bone‐binding assay. The concept of targeting drugs to bone with moderate affinity, while retaining oral bioavailability, has broad application to a variety of other bone‐targeted drugs. 相似文献
862.
Shengzhi Zhao Xingyu Zhang Qingpu Wang Jiaan Zheng Qidi Zhang Shujun Zhang Lianke Sun Huanchu Chen 《Optics & Laser Technology》2001,33(5)
Nd3+ : Ca4GdO(BO3)3, known as Nd : GdCOB, is a new self-frequency doubling laser crystal. Using Cr4+ : YAG as passive Q-switch, we have realized the Q-switched laser running at 0.53 μm with an Nd : GdCOB crystal. Meanwhile, the pulse width, the single pulse energy and the repetition rate under different small-signal transmission of Cr4+ : YAG and different pump conditions are measured and the numerical solutions of the coupling wave rate equations agree with the experimental results. 相似文献
863.
Jianhui Gu Feng Zhou Kah Tau Wan Tuan Kay Lim Siu-Chung Tam Yee Loy Lam Desheng Xu Zuhai Cheng 《Optics and Lasers in Engineering》2001,35(5)
Passive Q-switching of a diode-pumped Nd : YVO4 laser was demonstrated using GaAs as an output coupler and as a saturable absorber. When pumped with a 3-W diode laser at 809 nm, the highly compact laser produced 12-μJ pulses of 2.2 ns in duration at 1.064 μm in a single transverse mode, corresponding to a peak power of 5.6 kW. 相似文献