大学生课外体育锻炼状况调查与研究

运用文献资料法、特尔菲法、问卷调查法、数理统计法,调查、分析了长沙市大学生课外体育锻炼状况。提出了对策建议：增加体育理论课时,强化大学生体育理论知识和技能学习;创新组织方法和活动形式,吸引大学生积极参与课外体育锻炼;创造课外体育活动基本条件,培养大学生课外体育锻炼意识;大力营造体育锻炼环境。     

论多媒体技术进入高校体育课堂的必要性

采用文献资料法、逻辑分析法、数理统计法等方法,全面分析了多媒体技术在现代教育中的应用、高校体育教育的现状及多媒体技术进入高校体育课堂的必要性,指出:利用现代技术辅助完成教学任务是现在及未来教育发展的趋向.多媒体技术的运用,为体育教学提供了新的教学手段,对学生体育基础知识认知的发展,体育观念的更新,体育技能的提高以及思维品质的改善,都起到良好的促进作用.     

Synthesis and characterization of a Ni nanoparticle stabilized on Ionic liquid‐functionalized magnetic Silica nanoparticles for tandem oxidative reaction of primary alcohols

In this research, preparation of the magnetic nanoparticle, coating by a silica shell using (3‐aminopropyl) triethoxysilane and synthesis of a novel sulfonic acid‐substituted imidazolium‐based ionic liquid onto the surface of these particles via a multi‐component reaction, is described. The functionalized nanoparticles was loaded by Ni nanoparticles and characterized by means of techniques such as XRD, FTIR, SEM, EDX, TEM, TGA and ICP‐OES. The nanostructures have spherical shapes that ranged in size from 80 to 100 nm. The catalytic activity of these nanoparticles was tested in aerobic oxidation of primary alcohols that showed good performance in the wide range of primary alcohols in water at mild reaction conditions. As a second step of this work, the tandem oxidative synthesis of alkylacrylonitriles and bisindolylmethanes were investigated using primary alcohols under oxidation conditions. This catalyst system can be recovered using external magnet and reused for five consecutive cycles without significantly less of its activity.     

Non-metallic gold nanoclusters for oxygen activation and aerobic oxidation

In this review, oxygen activation and their aerobic oxidation over the Au nanoclusters are presented. The size-specificity, ligand engineering, and doping effects and the proposed reactions’ mechanism and the structure-activity relationships at the atomic level are also discussed.     

TBN as a metal-free reagent initiated sp3 C–H functionalization of glycine esters: Synthesis of quinoline-2-carboxylate esters

As a metal-free reagent, tert-butylnitrite (TBN) initiated aerobic sp³ C–H bond oxidation of glycine esters was achieved, providing a series of quinoline-2-carboxylates in good yields. The mechanistic investigation revealed that in the presence of molecular oxygen, TBN derived radicals were involved in the C–H bond oxidation and the terminal aromatization.     

Aerobic oxidation of alcohols using bismuth bromide as a catalyst

We developed an environmentally friendly method for aerobic oxidation of alcohols using a commercially available, relatively benign bismuth salt as a catalyst. We found that the catalytic combination of BiBr₃ with nitric acid is key for enhancing the reactivity. The reaction proceeds well under air, making the use of pure oxygen unnecessary. Each of the primary or secondary alcohols tested was oxidized to the corresponding aldehydes or ketones using this protocol.     

Facile Access to 3-Alkyl-Substituted 3-Hydroperoxy-2,4-pyrrolidinediones Using Manganese(III)-Catalyzed Aerobic Oxidation

Abstract

3-Alkyl-substituted 2,4-pyrrolidinediones were directly oxidized under very mild manganese(III)-catalyzed aerobic oxidation conditions to give the corresponding 3-hydroperoxy-2,4-pyrrolidinediones in quantitative yields. The scope and limitations for the synthesis of the hydroperoxyprrolidinediones are described.     

Solvent‐Free Aerobic Chemoselective Oxidation of β‐Ionone catalyzed by N‐Hydroxyphthalimide/Co(acac)2

β‐Ionone was oxidized with O₂ under solvent‐free conditions catalyzed by an N‐hydroxyphthalimide/Co(acac)₂ system in mild conditions with high conversion and excellent selectivity to oxo‐β‐ionone or 5,6‐epoxy‐β‐ionone in different reaction conditions, respectively.     

运动对去卵巢大鼠骨元素代谢的影响

用测定骨元素含量的方法，分析了运动对正常大鼠和切除双侧卵巢后的大鼠骨元素代谢的影响。将健康4个月龄雌性SD大鼠44只随机分成5组：（1）非去势非运动组；（2）非去势＋运动组；（3）假去势非运动组；（4）去势非运动组；（5）去势＋运动组。运动组用大鼠专用跑台中等运动强度训练，持续10周。结果表明，去卵巢大鼠骨Ca,Mg,S,Mn,Zn等含量显著降低，P含量显著增加。运动训练可使去卵巢大鼠降低的骨Ca,Mg,S,Mn,Zn等含量显著回升，骨P含量显著回降。提示中等强度运动训练可对抗由于去卵巢所引起的骨元素代谢紊乱。     

One-pot synthesis of phenol and cyclohexanone from cyclohexylbenzene catalyzed by N-hydroxyphthalimide (NHPI)

Synthesis of phenol and cyclohexanone in one pot was examined by means of the NHPI-catalyzed aerobic oxidation of cyclohexylbenzene. The aerobic oxidation of cyclohexylbenzene catalyzed by NHPI followed by treatment with sulfuric acid afforded phenol and cyclohexanone in good selectivities. Thus, the reaction of cyclohexylbenzene under atmospheric dioxygen (1 atm) by NHPI at 100 °C for 3 h followed by treatment with 0.3 M sulfuric acid at room temperature for 2 h resulted in phenol and cyclohexanone in 96 and 91% selectivity, respectively, at 25% conversion. This method was successfully extended to the one-pot synthesis of 4-hydroxyacetophenone and cyclohexanone.