首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   272篇
  免费   9篇
  国内免费   1篇
化学   135篇
晶体学   7篇
力学   21篇
综合类   1篇
数学   38篇
物理学   80篇
  2023年   2篇
  2022年   6篇
  2021年   14篇
  2020年   5篇
  2019年   11篇
  2018年   4篇
  2017年   10篇
  2016年   14篇
  2015年   9篇
  2014年   12篇
  2013年   35篇
  2012年   24篇
  2011年   25篇
  2010年   28篇
  2009年   20篇
  2008年   11篇
  2007年   9篇
  2006年   10篇
  2005年   6篇
  2004年   4篇
  2003年   4篇
  2002年   1篇
  2001年   1篇
  2000年   1篇
  1999年   1篇
  1997年   2篇
  1995年   1篇
  1994年   2篇
  1993年   1篇
  1990年   1篇
  1986年   2篇
  1983年   1篇
  1982年   1篇
  1981年   1篇
  1980年   1篇
  1976年   2篇
排序方式: 共有282条查询结果,搜索用时 15 毫秒
1.
Development of heat shock protein 90 (Hsp90) C‐terminal inhibitors has emerged as an exciting strategy for the treatment of cancer. Previous efforts have focused on modifications to the natural products novobiocin and coumermycin. Moreover, variations in both the sugar and amide moieties have been extensively studied, whereas replacements for the coumarin core have received less attention. Herein, 24 cores were synthesized with varying distances and angles between the sugar and amide moieties. Compounds that exhibited good anti‐proliferative activity against multiple cancer cell lines and Hsp90 inhibitory activity, were those that placed the sugar and amide moieties between 7.7 and 12.1 Å apart along with angles of 180°.  相似文献   
2.
3.
Journal of Thermal Analysis and Calorimetry - The increasing need of the modern era of technology for better ways to increase the heat transfer performance of thermal systems has made nanoliquids...  相似文献   
4.
5.
Zinc oxide nanoparticles based UV detector was fabricated on thermally oxidized silicon substrate. ZnO nanoparticle films were deposited using sol–gel route. The seed solution was prepared using two different solvents (methanol and isopropyl alcohol (IPA)). The surface morphology of the prepared films was characterized by FESEM. Structural characterization along with optical measurements was carried out using XRD and UV–vis spectroscopy. For the UV photo-detector, ZnO thin film prepared in IPA is selected based on their structural and optical analysis. The changes in photo-response of ZnO thin film with respect to time was studied under the dark and variable UV intensities. It was observed that the photocurrent increased with a factor of 4.82 under 1.16 mW of UV intensity. It is believe that the synthesized ZnO thin films have potential to use in the ultraviolet photo-detector applications.  相似文献   
6.
Abstract

When reacted with aldehydes, in situ generated title carbanions 2 can give phosphonodienes (4 or 6), phosphonolactones (5 or 8) or phosphonoalcohols 7, depending on structure of reagents and on reaction conditions.  相似文献   
7.
Ionics - A mercury(II) sensor was developed by using single-walled carbon nanotube (SWCNT) paste electrode modified with layered double Zn/Al hydroxide-3(4-methoxyphenyl)propionate nanocomposite...  相似文献   
8.
Biomolecules undergo motions on the micro‐to‐millisecond timescale to adopt low‐populated transient states that play important roles in folding, recognition, and catalysis. NMR techniques, such as Carr–Purcell–Meiboom–Gill (CPMG), chemical exchange saturation transfer (CEST), and R are the most commonly used methods for characterizing such transitions at atomic resolution under solution conditions. CPMG and CEST are most effective at characterizing motions on the millisecond timescale. While some implementations of the R experiment are more broadly sensitive to motions on the micro‐to‐millisecond timescale, they entail the use of selective irradiation schemes and inefficient 1D data acquisition methods. Herein, we show that high‐power radio‐frequency fields can be used in CEST experiments to extend the sensitivity to faster motions on the micro‐to‐millisecond timescale. Given the ease of implementing high‐power fields in CEST, this should make it easier to characterize micro‐to‐millisecond dynamics in biomolecules.  相似文献   
9.
Biomolecules undergo motions on the micro-to-millisecond timescale to adopt low-populated transient states that play important roles in folding, recognition, and catalysis. NMR techniques, such as Carr–Purcell–Meiboom–Gill (CPMG), chemical exchange saturation transfer (CEST), and R are the most commonly used methods for characterizing such transitions at atomic resolution under solution conditions. CPMG and CEST are most effective at characterizing motions on the millisecond timescale. While some implementations of the R experiment are more broadly sensitive to motions on the micro-to-millisecond timescale, they entail the use of selective irradiation schemes and inefficient 1D data acquisition methods. Herein, we show that high-power radio-frequency fields can be used in CEST experiments to extend the sensitivity to faster motions on the micro-to-millisecond timescale. Given the ease of implementing high-power fields in CEST, this should make it easier to characterize micro-to-millisecond dynamics in biomolecules.  相似文献   
10.
Ni0.5Zn0.5Fe2O4 has been synthesized using mechanical alloying method with two variables (milling time and ball-to-powder weight ratio (BPR)) were varied in order to study its effect on the magnetic properties of the material. The effects of these two variables were studied using XRD, SEM, TEM and later by impedance analyzer with the frequency range from 1 MHz to 1.8 GHz. The results obtained however show that there are no significant trends to relate the milling time and BPR with the permeability and losses of the material studied. After being sintered at 1150 °C, all the effects of alloying process seem to diminish.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号