变形速率对磨擦焊接头组织与性能的影响

研究了变形速率对低合金结构钢 3 5CrMo磨擦焊接头组织与力学性能的影响 .结果表明 ,增加变形速率可改善焊缝韧性 .焊缝韧性改善的机理为近缝区晶粒细化和硬度降低 .采用金相法、TEM法对近缝区粒状组织精细结构进行了观察 ,粒状组织小岛由M -A组成 .指出增加变形速率使近缝区金属强化机制为位错强化、一定数量的岛状第二相强化和细晶粒强化 .通过测试异种金属焊缝界面近区碳浓度的分布 ,探讨变形速率对磨擦焊最高加热温度的影响 ,增加变形速率可使磨擦焊界面的最高加热温度下降     

我国男子优秀跳远运动员助跑起跳技术GM(1,N)模型应用研究

通过对运动员有关参数的计算,建立我国男子优秀跳远运动员专项成绩与助跑起跳技术主要运动参数的动态协调模型,分析诊断运动员助跑、起跳技术与专项成绩的协调程度,找出影响成绩提高的技术重点     

对我国少数民族地区城镇化建设的再思考

加快城镇化建设,对促进我国少数民族地区协调发展,实现小康社会有着极为重要的意义.近年来,在我国城镇化建设取得辉煌成果的同时,我国民族地区在城镇化过程中存在着诸多问题,严重地阻碍了民族地区的发展.     

Integration of bio-inspired lanthanide-transition metal cluster and P-doped carbon nitride for efficient photocatalytic overall water splitting

Photosynthesis in nature uses the Mn₄CaO₅ cluster as the oxygen-evolving center to catalyze the water oxidation efficiently in photosystem II. Herein, we demonstrate bio-inspired heterometallic LnCo₃ (Ln = Nd, Eu and Ce) clusters, which can be viewed as synthetic analogs of the CaMn₄O₅ cluster. Anchoring LnCo₃ on phosphorus-doped graphitic carbon nitrides (PCN) shows efficient overall water splitting without any sacrificial reagents. The NdCo₃/PCN-c photocatalyst exhibits excellent water splitting activity and a quantum efficiency of 2.0% at 350 nm. Ultrafast transient absorption spectroscopy revealed the transfer of a photoexcited electron and hole into the PCN and LnCo₃ for hydrogen and oxygen evolution reactions, respectively. A density functional theory (DFT) calculation showed the cooperative water activation on lanthanide and O−O bond formation on transition metal for water oxidation. This work not only prepares a synthetic model of a bio-inspired oxygen-evolving center but also provides an effective strategy to realize light-driven overall water splitting.     

人文科学在全面建设小康社会中的作用

全面建设小康社会是新世纪具有中国特色的宏伟纲领,是社会主义经济、政治、文化全面发展的目标.以哲学、文学艺术、历史等为主要内容的人文科学在全面建设小康社会中具有十分重要的作用,它是全面建设小康社会经济上的精神支撑、政治上的思想基础、文化上的重要环节,并且是构建社会主义和谐社会的必备条件.     

论林逋的赠答送别诗

林逋的隐逸是内心的归隐,是心灵的自由和淡泊,而不是割断与世事的一切联系。他的酬唱赠答诗和送别诗数量颇多,几占其诗作总量的一半。这些诗歌反映了诗人的人生观和世界观、悠然自得的生命本真状态、待人的热情与真诚,以及对历史、现实的思考和评论。     

喜剧中的悲剧——《鸡犬不宁》中大红人物形象分析所折射出的悲喜文化

在都市故事充斥影院的今天,《鸡犬不宁》则带着浓厚的河南腔走到了观众的面前。再现了社会转型时期人们为生活拚搏和事业追求所经历的困惑,反映了生活中平凡的人们面对转行、重新择业、中年婚姻危机等诸多人生问题。大红这个富有张力的人物形象,和周遭的人物相类比,作者用黑色幽默的表现手法创造出喜剧效果,让观众在喜剧背后读出深刻的悲剧含义。     

论小康体育发展进程中农村民生体育建设

在新农村建设中,农村民生体育成为建设的重要组成部分。运用文献资料、逻辑分析等方法,在解读小康体育和民生体育的基础上,就小康体育发展背景下加强农村民生体育建设构想基本思路：坚持以人为本,牢固树立民生体育主体观;以农村学校体育为基础,推动农村民生体育健身工程实施;健全群众体育法律法规是农村民生体育建设的重要保障;开展村落春节运动会,是促进农村民生体育建设的重要依托;完善农村民生体育评价和激励机制,推动其健康有序发展。通过研究旨在为我国发展农村民生体育建设提供理论参考。     

兰州不同产地百合挥发油成分对比研究

采用水蒸气蒸馏法分别从甘肃省兰州市的榆中、七里河、西固不同产地百合中提取挥发油.用气相色谱-质谱联用技术（GC-MS）对其挥发油中的化学成分进行分离和结构鉴定,并运用气相色谱峰面积归一法,确定所鉴定出的化合物峰面积相对含量约占挥发油总量.结果显示,不同产地兰州百合挥发油的成分和含量存在一定差异,榆中百合挥发油共鉴定出23种化合物;七里河百合挥发油共鉴定出1 0种化合物;西固百合挥发油共鉴定出54种化合物.     

Ground reaction force characteristics of Tai Chi push hand

Abstract

Push Hand is an advanced training technique for the Yang-style old frame 108 forms Tai Chi Chuan. It is performed by two practitioners. To clarify how people use forces during Push Hand training, it is important to review the ground reaction force (GRF). Here, we quantify the characteristics of the GRF during Push Hand training. Kinematic data and GRF data from 10 Tai Chi Chuan practitioners (29.9 ± 7.87 years) were synchronously recorded using a three-dimensional motion analysis system (200 frames · s^?1) and three-dimensional force plates (1000 Hz). The resultant GRF for both feet for the 0%, 50% and 100% phases of attack and defence were compared to body weight using a paired-samples t-test. The differences in the resultant GRF between the 0%, 50% and 100% phases of attack and defence were tested by one-way repeated-measures ANOVA. The significance level was set to 0.05. The total resultant GRF was almost equal to the participant’s body weight in push hand. This result was consistent throughout the entire push hand process. Our results revealed that the GRF was comparable to the body weight, implying that practitioners do not push or resist their opponents during the push hand process.