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201.
A new simple receptor 1 based on aminosalicylimine was prepared. It exhibited an ‘off–on fluorescence type’ mode with high sensitivity in the presence of Zn2+. In particular, this chemosensor could clearly distinguish Zn2+ from Cd2+. Also, it could be a reusable chemosensor because the addition of EDTA quenched the fluorescence of the Zn2+-2·1 complex. Furthermore, receptor 1 had a sufficiently low detection limit (68 nM) in aqueous solutions, which implies that 1 could sense the nanomolar concentration of Zn2+. Therefore, this sensor has the ability to be a practical system for the monitoring of Zn2+ concentrations in aqueous samples. 相似文献
202.
Simultaneous determination of nine lignans from Schisandra chinensis extract using ultra‐performance liquid chromatography with tandem mass spectrometry in rat plasma,urine, and gastrointestinal tract samples: Application to the pharmacokinetic study of Schisandra chinensis
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You‐Jin Kim Hee Ju Lee Chul Young Kim Sun‐Young Han Young‐Won Chin Young Hee Choi 《Journal of separation science》2014,37(20):2851-2863
The fruit of Schisandra chinensis is a well‐known herbal medicine and dietary supplement due to a variety of biological activities including antihepatotoxic and antihyperlipidemic activities. However, the simultaneous validation methodology and pharmacokinetic investigation of nine lignans of S. chinensis extract in biological samples have not been proved yet. Thus, the present study was undertaken to develop the proper sample preparation method and simultaneous analytical method of schisandrol A, gomisin J, schisandrol B, tigloylgomisin H, angeloylgomisin H, schisandrin A, schisandrin B, gomisin N, and schisandrin C in the hexane‐soluble extract of S. chinensis to apply for the pharmacokinetic study in rats. All intra‐ and interprecisions of nine lignans were below 13.7% and accuracies were 85.1–115% and it is enough to evaluate the pharmacokinetic parameters after both intravenous and oral administration of hexane‐soluble extract of S. chinensis to rats. 相似文献
203.
Preparation of Yolk‐Shell and Filled Co9S8 Microspheres and Comparison of their Electrochemical Properties
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In this study, we report the first preparation of phase‐pure Co9S8 yolk–shell microspheres in a facile two‐step process and their improved electrochemical properties. Yolk–shell Co3O4 precursor microspheres are initially obtained by spray pyrolysis and are subsequently transformed into Co9S8 yolk–shell microspheres by simple sulfidation in the presence of thiourea as a sulfur source at 350 °C under a reducing atmosphere. For comparison, filled Co9S8 microspheres were also prepared using the same procedure but in the absence of sucrose during the spray pyrolysis. The prepared yolk–shell Co9S8 microspheres exhibited a Brunauer–Emmett–Teller (BET) specific surface area of 18 m2 g?1 with a mean pore size of 16 nm. The yolk–shell Co9S8 microspheres have initial discharge and charge capacities of 1008 and 767 mA h g?1 at a current density of 1000 mA g?1, respectively, while the filled Co9S8 microspheres have initial discharge and charge capacities of 838 and 638 mA h g?1, respectively. After 100 cycles, the discharge capacities of the yolk–shell and filled microspheres are 634 and 434 mA h g?1, respectively, and the corresponding capacity retentions after the first cycle are 82 % and 66 %. 相似文献
204.
205.
Dong Yunzhao Li Tingcheng You Xiangqian You Qingliang Sun Lang Xie Guangyong 《Research on Chemical Intermediates》2022,48(3):1151-1158
Research on Chemical Intermediates - Dichlorobenzonitriles are important organic intermediates for the production of many fine chemicals and are produced most economically and environment-friendly... 相似文献
206.
Minxia Huang Beiyang Yao Manhua Jiang Fuzhou Sun Jinsong You Fangfang Huang Yanping Zhao Shuming Wu Xinqian He Xuezhi Song 《Journal of mass spectrometry : JMS》2022,57(4):e4821
Two unknown solution degradants were found during the dissolution testing in 0.1-M HCl for olmesartan medoxomil (OLM) tablets. The structure of the degradants was identified and characterized by liquid chromatography–ultraviolet (LC–UV), liquid chromatography with tandem mass spectrometry (LC–MS/MS), and nuclear magnetic resonance (NMR) and demonstrated to be cyclization of tetrazole and benzene in the olmesartan (OL) and OLM structures. A series of studies including stress studies, simulation studies, and mechanism-based studies were performed to reveal the potential mechanisms that lead to the formation of the unknown degradants. The study results demonstrated that the degradation was catalyzed with radicals that originated from the metal ions leached from the inner surface of high-performance liquid chromatography (HPLC) glass vials with dissolved oxygen under acidic condition. Prerinsing the glass vials with acidic solution dissolved with EDTA can effectively avoid the generation of such oxidative impurities. The present work provides new insights into the understanding of degradation pathways of OLM, which might support the development of OLM tablets. 相似文献
207.
Science China Chemistry - Secrecy has received tremendous attention in modern information society. Innovative polymer-based fluorescent materials with multiple mode emission are quite desirable to... 相似文献
208.
Terence Zhi Xiang Hong Liming You Madhavi Dahanayaka Adrian Wing-Keung Law Kun Zhou 《Molecules (Basel, Switzerland)》2021,26(11)
In this study, molecular dynamics simulation is used to investigate the effects of water-based substitutional defects in zeolitic imidazolate frameworks (ZIF)-8 membranes on their reverse osmosis (RO) desalination performance. ZIF-8 unit cells containing up to three defect sites are used to construct the membranes. These substitutional defects can either be Zn defects or linker defects. The RO desalination performance of the membranes is assessed in terms of the water flux and ion rejection rate. The effects of defects on the interactions between the ZIF-8 membranes and NaCl are investigated and explained with respect to the radial distribution function (RDF) and ion density distribution. The results show that ion adsorption on the membranes occurs at either the nitrogen atoms or the defect sites. Complete NaCl rejection can be achieved by introducing defects to change the size of the pores. It has also been discovered that the presence of linker defects increases membrane hydrophilicity. Overall, molecular dynamics simulations have been used in this study to show that water-based substitutional defects in a ZIF-8 structure reduce the water flux and influence its hydrophilicity and ion adsorption performance, which is useful in predicting the type and number of defect sites per unit cell required for RO applications. Of the seven ZIF-8 structures tested, pristine ZIF-8 exhibits the best RO desalination performance. 相似文献
209.
Zhaorui Li Dr. Kristin Werner Lu Chen Aiping Jia Dr. Kun Qian Dr. Jian-Qiang Zhong Dr. Rui You Dr. Lihui Wu Liyuan Zhang Dr. Haibin Pan Prof. Dr. Xin-Ping Wu Prof. Dr. Xue-Qing Gong Dr. Shamil Shaikhutdinov Prof. Weixin Huang Prof. Dr. Hans-Joachim Freund 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(16):5268-5276
The study reports the first attempt to address the interplay between surface and bulk in hydride formation in ceria (CeO2) by combining experiment, using surface sensitive and bulk sensitive spectroscopic techniques on the two sample systems, i.e., CeO2(111) thin films and CeO2 powders, and theoretical calculations of CeO2(111) surfaces with oxygen vacancies (Ov) at the surface and in the bulk. We show that, on a stoichiometric CeO2(111) surface, H2 dissociates and forms surface hydroxyls (OH). On the pre-reduced CeO2−x samples, both films and powders, hydroxyls and hydrides (Ce−H) are formed on the surface as well as in the bulk, accompanied by the Ce3+ ↔ Ce4+ redox reaction. As the Ov concentration increases, hydroxyl is destabilized and hydride becomes more stable. Surface hydroxyl is more stable than bulk hydroxyl, whereas bulk hydride is more stable than surface hydride. The surface hydride formation is the kinetically favorable process at relatively low temperatures, and the resulting surface hydride may diffuse into the bulk region and be stabilized therein. At higher temperatures, surface hydroxyls can react to produce water and create additional oxygen vacancies, increasing its concentration, which controls the H2/CeO2 interaction. The results demonstrate a large diversity of reaction pathways, which have to be taken into account for better understanding of reactivity of ceria-based catalysts in a hydrogen-rich atmosphere. 相似文献
210.
S. S. Qian Y. N. Wang M. M. Zhen Y. N. Li D. Huang Z. L. You H. L. Zhu 《Russian Journal of Coordination Chemistry》2014,40(2):88-92
Reaction of [MoO2(Acac)2] (Acac = acetylacetonate) with two similar hydrazone ligands in methanol yielded two mononuclear molybdenum(VI) oxocomplexes with general formula [MoO2(L)(CH3OH)], where L = L1 = (4-nitrophenoxy)acetic acid [1-(3-ethoxy-2-hydroxyphenyl)methylidene]hydrazide (H2L1) and L = L2 = (4-nitrophenoxy)acetic acid [1-(5-bromo-2-hydroxyphenyl)methylidene]hydrazide (H2L2). Crystal and molecular structures of the complexes were determined by single crystal X-ray diffraction method. All investigated compounds were further characterized by elemental analysis and FT-IR spectra. Single crystal X-ray structural studies indicate that the hydrazone ligands coordinate to the MoO2 cores through enolate oxygen, phenolate oxygen, and azomethine nitrogen. The Mo atoms in both complexes are in octahedral coordination. 相似文献