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   104篇
  免费   3篇
化学   94篇
晶体学   2篇
数学   4篇
物理学   7篇
  2022年   3篇
  2021年   11篇
  2020年   10篇
  2019年   12篇
  2018年   1篇
  2017年   2篇
  2016年   4篇
  2015年   4篇
  2014年   6篇
  2013年   8篇
  2012年   11篇
  2011年   3篇
  2010年   3篇
  2009年   5篇
  2008年   6篇
  2007年   7篇
  2006年   1篇
  2005年   5篇
  2004年   3篇
  2003年   1篇
  1995年   1篇
排序方式: 共有107条查询结果,搜索用时 78 毫秒
81.
Applied Biochemistry and Biotechnology - Altered plasma levels of branched-chain amino acids (BCAAs) and aromatic amino acids (AAAs) may predict the development of insulin resistance and other type...  相似文献   
82.
Abstract

This review supply an inclusive survey of the recent progress in the chemistry of 4,6‐dimethyl-3-amino-3H-pyrazolo[3,4-b]pyridine concerning the synthesis and reactions and biological activity over the period from the year 1990 to the year 2020.  相似文献   
83.
Journal of Thermal Analysis and Calorimetry - The thermal decomposition of the third-generation beta-blocker nebivolol (NEB) was investigated using thermogravimetric analysis (TG) under isothermal...  相似文献   
84.
85.
86.
87.
Nanoworld is an attractive sphere with the potential to explore novel nanomaterials with valuable applications in medicinal science. Herein, we report an efficient and ecofriendly approach for the synthesis of Nickel oxide nanoparticles (NiO NPs) via a solution combustion method using Areca catechu leaf extract. As-prepared NiO NPs were characterized using various analytical tools such as powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and UV-Visible spectroscopy (UV-Vis). XRD analysis illustrates that synthesized NiO NPs are hexagonal structured crystallites with an average size of 5.46 nm and a hexagonal-shaped morphology with slight agglomeration. The morphology, size, and shape of the obtained material was further confirmed using SEM and TEM analysis. In addition, as-prepared NiO NPs have shown potential antidiabetic and anticancer properties. Our results suggest that the inhibition of α-amylase enzyme with IC 50 value 268.13 µg/mL may be one of the feasible ways through which the NiO NPs exert their hypoglycemic effect. Furthermore, cytotoxic activity performed using NiO NPs exhibited against human lung cancer cell line (A549) proved that the prepared NiO NPs have significant anticancer activity with 93.349 μg/mL at 50% inhibition concentration. The biological assay results revealed that NiO NPs exhibited significant cytotoxicity against human lung cancer cell line (A549) in a dose-dependent manner from 0–100 μg/mL, showing considerable cell viability. Further, the systematic approach deliberates the NiO NPs as a function of phenolic extracts of A. catechu with vast potential for many biological and biomedical applications.  相似文献   
88.
Poly(m-phenylene diamine) has been synthesized and characterized by physical and spectral techniques. The effect of doping Cr, Co and Ni ions on the spectral, thermal and optical properties has been studied. Optical band gap measurements indicated that, doped polymers have wider optical band gap than the pure one. The effect of doping on the thermal stability differs according to the doped metal ion. The doped with Cr ions poly(m-phenylenediamine) has been used as a precursor of mesoporous Cr2O3 nanoparticles, which have been also characterized by XRD and HR-TEM.  相似文献   
89.
Ultra performance liquid chromatography (UPLC) when coupled to ion mobility (IMS)/orthogonal acceleration time of flight mass spectrometry is a suitable technique for analyzing complex mixtures such as the black tea thearubigins. With the aid of this advanced instrumental analysis, we were able to separate and identify different isomeric components in the complex mixture which could previously not be differentiated by a conventional high performance liquid chromatography/tandem mass spectrometry. In this study, the difference between isomeric structures theasinensins, proanthocyanidins B‐type and rutin (quercetin‐3O‐rutinoside) were studied, and these are present abundantly in many botanical sources. The differentiation between these structures was accomplished according to their acquired mobility drift times differing from the traditional investigations in mass spectrometry, where calculation of theoretical collisional cross sections allowed assignment of the individual isomeric structures. The present work demonstrates UPLC–IMS‐MS as an efficient technology for isolating and separating isobaric and isomeric structures existing in complex mixtures discriminating between them according to their characteristic fragment ions and mobility drift times. Therefore, a rational assignment of isomeric structures in many phenolic secondary metabolites based on the ion mobility data might be useful in mass spectrometry‐based structure analysis in the future. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   
90.
Multivariate spectrophotometric calibration and liquid chromatographic (LC) methods were applied to the determination of 2 multicomponent mixtures containing diprophylline, guaiphenesin, methylparaben, and propylparaben (Mixture 1), or clobutinol, orciprenaline, saccharin sodium, and sodium benzoate (Mixture 2). For the multivariate spectrophotometric calibration methods, principal component regression (PCR) and partial least-squares regression (PLS-1), a calibration set of the mixtures consisting of the components of each mixture was prepared in 0.1 M HCl. Analytical figures of merit such as sensitivity, selectivity, limit of quantitation, and limit of detection were determined for both PLS-1 and PCR. The LC separation was achieved on a reversed-phase C18 analytical column by using isocratic elution with 20 mM potassium dihydrogen phosphate, pH 3.3-acetonitrile (55 + 45, v/v) as the mobile phase and UV detection at 260 and 220 nm for Mixture 1 and Mixture 2, respectively. The proposed methods were validated and successfully applied to the analysis of pharmaceutical formulations and laboratory-prepared mixtures containing the 2 multicomponent combinations.  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