Aerobic Oxidation of Alcohols to Aldehydes and Ketones with Recyclable Pd Catalysts on Cross-linked 1,10-Phenanthroline Polymers

A 1,10-phenanthroline based polymer named PPPhen(i.e., polymer from pyrene 1,10-phenanthrolin) was prepared by the Friedel-Crafts reaction of 1,10-phenanthroline and pyrene cross-linked with dimethoxymethane. The related Pd catalyst Pd@PPPhen was prepared by supporting Pd nanoparticles(NPs) on the PPPhen material. PPPhen and Pd@PPPhen were characterized by means of scanning electron microscopy(SEM), transmission electron microscopy, N₂ adsorption-desorption, Fourier-transform infrared and X-ray photoelectron spectroscopy analyses. The results showed that PPPhen polymer was highly porous and that the phenanthroline group can enhance the stability of the Pd nanoparticles. Pd@PPPhen also exhibited good catalytic activity in the aerobic oxidation of alcohols to aldehydes and ketones, and Pd@PPPhen was recyclable with durable activity and retentive structures.     

大学生体育锻炼与心理健康关系的研究

通过问卷调查了解到,大学生体育锻炼习惯、兴趣与心理健康水平呈显著性关系,体育锻炼的形式对心理健康水平有着重要的影响,体育锻炼类型也对大学生心理健康水平有一定的影响,体育锻炼与心理健康存在着明显的互动关系.     

摔跤训练对人体无氧工作能力的影响

对30名专业摔跤运动员进行Wingate无氧实验.为探讨摔跤训练对人体无氧工作能力的影响,结果表明,摔跤训练可提高人体无氧功率能力,加快运动启动速度;用Wingate无氧实验评价时,前10 s无氧功率值的高低比其递增的幅度,更能反映摔跤训练效果;30 s Wingate无氧实验主要反映出摔跤训练对人体无氧功率的影响,而对无氧能力的评价不明显;Wingate无氧实验对评定摔跤训练效果和水平更具有指导意义.     

Copper‐Catalyzed Aerobic Oxidative Reaction of Sulfonyl Hydrazides with Alcohols: An Easy Access to Sulfinates

A Cu‐catalyzed aerobic oxidative reaction between sulfonyl hydrazides and alcohols has been developed. In this reaction, sulfonyl hydrazides act as the sulfinic acid precursors to react with alcohols, resulting in sulfinic esters with up to 72 % yield. This catalytic system tolerates a wide range of sulfonyl hydrazide substrates, and represents a new strategy for the transformation of readily available sulfonyl hydrazides.     

项目投资时机及投资概率分析

针对实物期权理论中存在的不足,运用鞅理论分析研究了市场环境下的确定性和不确定性因素对实物资产项目投资决策的影响.首先,通过鞅方法建立了反映投资时机和投资回报临界值之间关系的投资时机模型;然后,使用测度变换评价了项目投资能够被实施的可能性.研究结果表明确定性因素对投资时机和投资回报临界值具有相反作用的影响,不确定性因素则均具有正向作用的影响,且在确定性因素取值较小情况下,不确定性对投资却具有促进作用.     

国际上运动对人体骨骼影响的知识基础及研究热点

目的:探讨当前国际上运动对骨骼影响研究的知识基础及研究热点.方法:利用计算机检索Web of Science数据库中2010-2016年运动与骨骼相关文献4587篇,运用CitespaceⅢ可视化软件绘制共现图谱,分析研究国家机构分布、高被引文献及高频关键词.结果:美国、英国、澳大利亚是该研究领域的中坚力量;研究热点主要集中在不同运动干预对绝经妇女、发育期青少年儿童及老年人三类人群骨骼的影响;知识基础方向主要为骨骼功能适应性理论的实验与发展.结论:以客观数据和图谱为依据,透析运动对骨骼影响研究领域的知识基础和热点,为该领域的后续研究提供参考.     

The early exercise region for Bermudan options on two underlyings

This paper investigates the early exercise region for Bermudan options on two underlying assets. We present a set of analytical validation results for the early exercise region which can be used as a means of validating pricing techniques. When all strike prices are identical we show the existence of an intersection point such that for any asset price pair below this point early exercise is always optimal. We develop an approximation to this point in the two asset put case. When the strike prices are not all equal, we show that three separate cases exist for the early exercise region. For a Bermudan put on two assets we present these cases and show that there exists a critical point in which the boundaries of the two asset early exercise region bifurcate. Comparisons are drawn between the Bermudan results presented and the corresponding American option results.     

封闭式运动减肥对肥胖青少年体质健康的影响

对44名14～19岁肥胖青少年进行6周的封闭式饮食控制及运动,测定实验对象的身体形态、身体机能、身体素质和血液健康等指标.通过数理统计方法对实验所测得的数据进行分析.结果表明:肥胖青少年的脂肪量、体质量、体脂率都有明显的下降(P0.05);肺活量逐渐上升,身体素质指标(耐力、柔韧、50 m跑)与血液健康指标(血脂TC、甘油三酯TG、空腔胰岛素FINS)都呈非常明显改善(P0.01).封闭式运动减肥对青少年肥胖者体质健康具有良好的效能表现.     

The determination of organochlorine compounds and petroleum hydrocarbons in a seaweed sample: results of a world-wide intercomparison exercise

A seaweed sample (Fucus sp.) was prepared, homogenised and distributed to laboratories worldwide as the IAEA-140 intercomparison material for the analysis of organochlorine compounds and petroleum hydrocarbons. A total of 80 laboratories from 51 countries reported results for this sample. The data sets reported by laboratories were evaluated statistically and the mean concentration values could be computed with 95% confidence limits for a large number of analytes. The accuracy of the analytical performance of each laboratory has been introduced by using Z-scores. The spread of results reported generally indicates that the accurate determination of many persistent organic pollutants, such as hexachlorobenzene, lindane, Aroclors or fluoranthene, is still difficult for many laboratories. The final results of this intercomparison exercise enable individual participants to assess their performance and, where necessary, to introduce appropriate modifications in their analytical procedures. Furthermore, as a series of statistical criteria was fulfilled for a number of compounds, the sample IAEA-140 can now be used as a reference material for quality control in the determination of chlorinated compounds and petroleum hydrocarbons in environmental samples.     

热敏灸对运动大鼠运动能力和心肌、骨骼肌细胞线粒体过氧化损伤的影响

目的研究热敏灸对运动大鼠运动能力和心肌、骨骼肌细胞线粒体过氧化损伤的影响。方法将40只大鼠随机分为正常对照组、单纯运动组、运动+普通悬灸组和运动+热敏灸组,采用14 d递增大强度跑台运动训练和生物化学的方法,观察热敏灸对运动大鼠运动能力和心肌、骨骼肌细胞线粒体过氧化损伤的影响。结果运动+热敏灸组大鼠疲劳相关症状显著改善,跑台力竭时间显著高于运动+普通悬灸组和单纯运动组。运动+热敏灸组大鼠心肌、骨骼肌细胞线粒体SOD酶活性高于单纯运动组、运动+普通悬灸组,心肌细胞线粒体SOD酶活性低于正常对照组,但骨骼肌细胞线粒体SOD酶活性与正常对照组比较,差异无显著性;MDA含量低于单纯运动组和运动+普通悬灸组,但高于正常对照组。结论热敏灸足三里穴具有明显的抗运动性疲劳作用,机理与热敏灸降低过度运动大鼠心肌和骨骼肌细胞线粒体过氧化损伤有关。