38 research outputs found

    Selective Oxidation of 1,2-propane Glycol to Methylglyoxal: the Preparation of Ag/ZrO2 Catalysts by Biosynthesis Methods

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    丙酮醛(MGX)是一种重要的有机合成中间体,主要用作药物中间体,也广泛用于制备农药、食品添加剂等。丙酮醛通过与甲醛、氨等反应可以制得医药中间体4-甲基咪唑,还可以通过歧化反应制得用途广泛的乳酸。近年来随着咪唑以及呋喃酮等香料需求的增加,丙酮醛的需求量也日益增加,但它的天然存在量很少,而国内丙酮醛的生产起步晚,且规模较小。另外,丙酮醛的传统制备方法中所采用的催化剂多为电解银催化剂,电解银催化剂在反应温度低于500℃时活性不够,产物中有较多副产物羟基丙酮,而在高于500℃时,银微晶在高温条件下容易快速团聚导致催化活性下降。因此探索和深入研究在低温条件下具有高催化性能的催化剂,是丙酮醛实现经济、“绿...As an important organic intermediate, methylglyoxal(MGX) is mainly used as drug intermediates, and also has important applications in agricultural pesticide, food additives and so on. MGX can react with formaldehyde and ammonia to produce imidazole, which is a kind of drug intermediates. In addition, lactic acid can be produced by disproportionation reaction of MGX. Recently, the demand for MGX in...学位:工学硕士院系专业:化学化工学院化学工程与生物工程系_工业催化学号:2062007115090

    Some Aspects of Cable Design for Fast Cycling Superconducting Synchrotron Magnets

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    Fast cycling superconducting magnets: new design for ion synchrotrons

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    Background: functional assessment is an important component of the management of older adults in the emergency department (ED) as the function level has been identified as a predictor of adverse events including ED re-presentation. A systematic review (SR) of all functional assessments utilised in EDs has not been undertaken making assessment selection, on the basis of evidence, difficult for staff. Objective: this SR: (i) identified functional assessments that have been utilised in ED settings, (ii) examined what psychometric properties analysis has been completed and (iii) established recommendations for practice. Methods: electronic database searching was completed utilising key search terms. Articles were reviewed using pre-determined inclusion criteria. Each study was appraised using quality criteria for aspects of validity and reliability in addition to clinical utility, interpretability and responsiveness. Recommendations for practice were determined on the basis of the extent of psychometric data generated in ED settings and whether or not the assessment was specifically developed for ED use. Results: a total of 332 articles were identified of which 43 articles utilising 14 functional assessments were retained. Psychometric testing was scarce. Functional assessment has been reported internationally and only with older adults. Following appraisal four assessments [the Identification of Seniors at Risk (ISAR), Triage Risk Stratification Tool (TRST), Older Adult Resources and Services (OARS) and Functional Status Assessment of Seniors in Emergency Departments (FSAS-ED)] were recommended for practice with moderate reservations. Conclusion: the ISAR or TRST are suitable for fast screening, whereas the OARS or FSAS-ED are more suitable for a comprehensive understanding of functional performance. Further research is warranted and recommendations for ED assessment may change as more becomes known about psychometric properties and clinical applications of other assessments

    Optimization of a superferric nuclotron type dipole for the GSI fast pulsed synchrotron

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