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   271篇
  免费   7篇
  国内免费   15篇
化学   142篇
晶体学   1篇
力学   71篇
综合类   7篇
数学   14篇
物理学   58篇
  2023年   3篇
  2022年   4篇
  2021年   5篇
  2020年   2篇
  2019年   5篇
  2018年   8篇
  2017年   8篇
  2016年   8篇
  2015年   12篇
  2014年   5篇
  2013年   7篇
  2012年   8篇
  2011年   12篇
  2010年   13篇
  2009年   14篇
  2008年   9篇
  2007年   12篇
  2006年   14篇
  2005年   21篇
  2004年   15篇
  2003年   24篇
  2002年   27篇
  2001年   4篇
  2000年   7篇
  1999年   6篇
  1998年   3篇
  1997年   1篇
  1996年   3篇
  1995年   1篇
  1994年   1篇
  1992年   1篇
  1991年   2篇
  1990年   1篇
  1989年   2篇
  1988年   3篇
  1987年   1篇
  1986年   1篇
  1985年   1篇
  1984年   1篇
  1981年   1篇
  1980年   3篇
  1978年   5篇
  1977年   2篇
  1976年   3篇
  1974年   2篇
  1957年   1篇
  1955年   1篇
排序方式: 共有293条查询结果,搜索用时 15 毫秒
291.
Cephalanthus tetrandrus (Roxb.) Ridsd. et Badh. F. (CT) belongs to the Rubiaceae family. Its dried leaves are widely used in traditional Chinese medicine to treat enteritis, dysentery, toothache, furuncles, swelling, traumatic injury, fracture, bleeding, and scalding. In order to further clarify the unknown chemical composition of CT, a rapid strategy based on UHPLC-Q-exactive orbitrap was established for this analysis using a Thermo Scientific Hypersil GOLDTM aQ (100 mm × 2.1 mm, 1.9 µm) chromatographic column. The mobile phase was 0.1% formic acid water–acetonitrile, with a flow rate of 0.3 mL/min and injection volume of 2 µL; for mass spectrometry, an ESI ion source in positive and negative ion monitoring modes was adopted. A total of 135 chemicals comprising 67 chlorogenic acid derivatives, 48 flavonoids, and 20 anthocyanin derivatives were identified by comparing the mass spectrum information with standard substances, public databases, and the literature, which were all discovered for the first time in this plant. This result broadly expands the chemical composition of CT, which will contribute to understanding of its effectiveness and enable quality control.  相似文献   
292.
Artemisiae Argyi Folium (Aiye in Chinese) has been widely used since ancient times. In the Lingnan region (Southern China), the leaf of Artemisia verlotorum Lamotte, which is named Hongjiaoai (HJA) because the roots are red (Hongjiao means red foot in Chinese), has been used as a local substitute for Artemisiae Argyi Folium. The plant has a long medicinal and edible history that can be traced to the Jin Dynasty. However, there is no systematic and reliable method to control the quality of Artemisiae Verlotori Folium. In this study, a comprehensive method involving high-performance liquid chromatography coupled with diode array detection and quadrupole-time-of-flight high-definition mass spectrometry was established to identify and quantify eight constituents (including organic acids and flavonoids) in Artemisiae Verlotori Folium and Artemisiae Argyi Folium as well as high-performance liquid chromatography fingerprints of the two varieties. Moreover, dissimilarities of chemical compositions among the two varieties were further investigated by orthogonal partial least squares discrimination analysis and cluster analysis. This research not only explored the similarities and differences between Artemisiae Verlotori Folium and Artemisiae Argyi Folium in eight components but also provided a qualitative and quantitative analytical method that quickly, accurately, and comprehensively assesses the quality of Artemisiae Verlotori Folium.  相似文献   
293.
As a main source for the recognition and identification of lead compounds, traditional Chinese medicine plays a pivotal role in preventing diseases for years. However, screening bioactive compounds from traditional Chinese medicine remains challenging because of the complexity of the systems and the occurrence of the synergic effect of the compounds. The infructescence of Platycarya strobilacea Sieb. et Zucc is prescribed for allergic rhinitis treatment with unknown bioactive compounds and unclear mechanisms. Herein, we immobilized the β2-adrenoceptor and muscarine-3 acetylcholine receptor onto the silica gel surface to prepare the stationary phase in a covalent bond through one step. The feasibility of the columns was investigated by the chromatographic method. Ellagic acid and catechin were identified as the bioactive compounds targeting the receptors. The binding constants of ellagic acid were calculated to be (1.56 ± 0.23)×107 M−1 for muscarine-3 acetylcholine receptor and (2.93 ± 0.15)×107 M−1 for β2-adrenoceptor by frontal analysis. While catechin can bind with muscarine-3 acetylcholine receptor with an affinity of (3.21 ± 0.05)×105 M−1. Hydrogen bonds and van der Waals’ force were the main driving forces for the two compounds with the receptors. The established method provides an alternative for multi-target bioactive compound screening in complex matrices.  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