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排序方式: 共有610条查询结果,搜索用时 15 毫秒
221.
Krishna C. Majumdar Author VitaeAuthor Vitae 《Tetrahedron》2007,63(4):793-826
This review describes the formation of five- and six-membered heterocyclic rings in various organic molecules by radical cyclisation and covers mostly the literature published in 2005. 相似文献
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This paper describes important factors that need to be considered when determining the uncertainty in the calibration of the HDA200 circumaural earphones which are used in audiometric and psychoacoustic tests. This paper describes the instruments that were used, the procedures and the results of the measurements. Each of these measurements generated an uncertainty component and the final calculus of the total uncertainty was computed using standard procedures. This paper highlights the necessity for researches on the contribution that the artificial ears have on the uncertainty and establishes a calibration method. 相似文献
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Synthesis of quinazolinones and quinazolines 总被引:1,自引:0,他引:1
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Xiaoqing Jiang Bingqian Zhang Guangyue Yang Zhongmin Zhou Xin Guo Fengshan Zhang Shitao Yu Shiwei Liu Shuping Pang 《Angewandte Chemie (International ed. in English)》2023,62(22):e202302462
Carbonyl functional materials as additives are extensively applied to reduce the defects density of the perovskite film. However, there is still a lack of comprehensive understanding for the effect of carbonyl additives to improve device performance. In this work, we systematically study the effect of carbonyl additive molecules on the passivation of defects in perovskite films. After a comprehensive investigation, the results confirm the importance of molecular dipole in amplifying the passivation effect of additive molecules. The additive with strong molecular dipole possesses the advantages of enhancing the efficiency and stability of perovskite solar cells (PSCs). After optimization, the companion efficiency of PSCs is 23.20 %, and it can maintain long-term stability under harsh conditions. Additionally, a large-area solar cell module-modified DLBA was 20.18 % (14 cm2). This work provides an important reference for the selection and designing of efficient carbonyl additives. 相似文献
229.
Marta Lores Maria LlompartAuthor VitaeGerardo Alvarez-RiveraAuthor Vitae Eugenia GuerraAuthor VitaeMarlene VilaAuthor Vitae Maria CeleiroAuthor VitaeJ. Pablo LamasAuthor Vitae Carmen Garcia-JaresAuthor Vitae 《Analytica chimica acta》2016
Cosmetic products placed on the market and their ingredients, must be safe under reasonable conditions of use, in accordance to the current legislation. Therefore, regulated and allowed chemical substances must meet the regulatory criteria to be used as ingredients in cosmetics and personal care products, and adequate analytical methodology is needed to evaluate the degree of compliance. This article reviews the most recent methods (2005–2015) used for the extraction and the analytical determination of the ingredients included in the positive lists of the European Regulation of Cosmetic Products (EC 1223/2009): comprising colorants, preservatives and UV filters. It summarizes the analytical properties of the most relevant analytical methods along with the possibilities of fulfilment of the current regulatory issues. The cosmetic legislation is frequently being updated; consequently, the analytical methodology must be constantly revised and improved to meet safety requirements. The article highlights the most important advances in analytical methodology for cosmetics control, both in relation to the sample pretreatment and extraction and the different instrumental approaches developed to solve this challenge. 相似文献
230.
Kevin D. ClarkAuthor Vitae Omprakash NachamAuthor VitaeJeffrey A. PurslowAuthor Vitae Stephen A. PiersonAuthor VitaeJared L. Anderson 《Analytica chimica acta》2016
Magnetic ionic liquids (MILs) have recently generated a cascade of innovative applications in numerous areas of analytical chemistry. By incorporating a paramagnetic component within the cation or anion, MILs exhibit a strong response toward external magnetic fields. Careful design of the MIL structure has yielded magnetoactive compounds with unique physicochemical properties including high magnetic moments, enhanced hydrophobicity, and the ability to solvate a broad range of molecules. The structural tunability and paramagnetic properties of MILs have enabled magnet-based technologies that can easily be added to the analytical method workflow, complement needed extraction requirements, or target specific analytes. This review highlights the application of MILs in analytical chemistry and examines the important structural features of MILs that largely influence their physicochemical and magnetic properties. 相似文献