纳米金光度法快速检测水中雌激素     

余玲  ;张银堂  ;张丹华  ;陈冉  ;陈芳  ;韦秀华  ;徐茂田 《商丘师范学院学报》2014,(9):30-33

利用紫外可见光度法研究了纳米金粒子与雌激素的相互作用,纳米金与雌酮发生相互作用后,吸收光谱明显红移.吸光度比值A/A520与雌酮浓度的对数值在1.0×10-7~1.0×10-5mol/L范围内呈良好的线性关系,检测限为4.7×10-9mol/L.本研究建立了一种快速、方便检测雌激素的新方法,为水体、奶粉、食品中雌激素的检测提供了一条新的途径.  相似文献   

我国城乡教育一体化的实现逻辑、现实冲突与未来走向     

张源源  刘善槐  邬志辉 《辽宁教育研究》2014,(9):54-58

现阶段我国正以强制性制度变迁为主导来推进城乡教育一体化。强制性制度变迁存在局限性,在实践的过程中带来了如实现形式表面化、实现动力不足、实现目标简单化等一系列问题。为了改变这种状况,需要采用强制性制度变迁与诱致性制度变迁相结合的方式,激发自下而上的改革动力,保障城乡教育一体化的可持续性。  相似文献   

二苯甲C=O变温红外光谱研究     

胡瑞省  刘会茹  雷克  刘建垒  苗云飞  王萌  杨婷  于宏伟 《石家庄学院学报》2014,(6):24-27,92

采用变温红外光红外技术在303-393K范围内,分别测定二苯甲酮羰基伸缩振动(νC=O)的一维红外光谱、二阶导数红外光谱及去卷积红外光谱。实验发现:二苯甲酮相变的临界温度为325-326 K,并进一步研究了其相变机理。  相似文献   

二乙基二硫代氨基甲酸钠对冷轧钢在乙酸溶液中的缓蚀性能     

余晋苗  白玮  杨艳  史英浩  郭俊明 《常熟理工学院学报》2014,(2):66-69

采用Tafel极化曲线法和电化学交流阻抗谱法测定不同浓度缓蚀剂在0.2 mol·L-1乙酸介质中对冷轧钢的缓蚀作用.结果表明：在20℃、0.2 mol·L-1乙酸溶液中二乙基二硫代氨基甲酸钠对冷轧钢具有较好的缓蚀效果,缓蚀率随着缓蚀剂浓度的增加而增大,当缓蚀剂的浓度为3×10-3 mol·L-1时,缓蚀率达到85%,属于阴极型缓蚀剂.二乙基二硫代氨基甲酸钠在冷轧钢表面的吸附符合Langmuir吸附等温式,其吸附为自发进行的物理和化学吸附.  相似文献   

茜素黄R与牛血清白蛋白光谱学及分子对接研究     

吴承燕 《福建师大福清分校学报》2014,(2):49-51,56

在中性条件下,利用紫外可见分光光谱法和分子对接技术研究了偶氮类小分子染料茜素黄R与牛血清白蛋白的相互作用。紫外可见光谱表明,茜素黄R与牛血清白蛋白键合形成的复合物最大吸收波长为386nm,比茜素黄R红移了13nm,二者的结合摩尔比约为1:1,表观摩尔吸光系数为8.70×103dm3·mol-1·cm-1。结合分子模拟技术研究复合物的结合模式和键合机制,判定茜素黄R在牛血清白蛋白上的结合位置位于site I结合位点,讨论二者之间的作用力以静电作用为主,同时也包括疏水作用和氢键。分子对接模拟结果与实验结论一致。  相似文献   

Muscle activation characteristics in cross-country skiers with a history of anterior compartment pain     

Peter Federolf  Emily Bakker 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(4):452-463

A large proportion of elite cross-country skiers suffer from chronic anterior compartment syndrome (CACS). This study used surface electromyograms (EMGs) to investigate whether differences existed in the activation characteristics of the tibialis anterior muscle between elite cross-country skiers with a history of anterior compartment pain (symptomatic group) and a pain-free control group. Based on self-reported pain symptoms, twelve young, national-level cross-country ski athletes were assigned to a symptomatic group (N = 5), a control group (N = 4), or analyzed individually if their diagnosis was not certain (N = 3). During skating, EMGs were recorded on five lower leg muscles. The relative increase in EMG power per step when increasing the effort level of skating was larger in the symptomatic group than in the control group for tibialis anterior (143 ± 12% vs. 125 ± 23%; Cohen's d = 1.17), peroneus longus (123 ± 24% vs. 107 ± 6%; d = 0.91), and gastrocnemius lateralis (167 ± 51% vs. 117 ± 12%; d = 1.64). The symptomatic group showed more power in the lower frequency bands of the tibialis anterior's EMG spectra (p < 0.001), whereas no group differences were found in other muscles (all p>0.2). Within the step cycle, these differences appeared in the swing phase and in the gliding phase during single leg support. The observed differences in the EMG spectra may serve as an early identification of athletes who are at risk of developing CACS.  相似文献   

Differences in energy expenditure between high- and low-volume training     

《European Journal of Sport Science》2013,13(4):422-430

Abstract

Several studies have examined energy expenditure in various sports but there is a lack of research on the contribution of exercise and habitual activity during different training periods. This study examined changes in total daily energy expenditure (TDEE) and its components during high- and low-volume training periods. Further, changes in time spent in sedentary, light, moderate and vigorous activity in response to different training volumes were explored. Energy expenditure was measured in 15 male endurance athletes during 2 non-consecutive weeks – 1 week of high volume (>13 hours) training and another week of low volume (<7 hours) training. The SenseWear Pro 3 Armband, individual heart-rate-oxygen consumption regression and indirect calorimetry was used to measure non-exercise activity thermogensis (NEAT), exercise energy expenditure (EEE) and resting metabolic rate, respectively. Time spent at different intensities was assessed using previously established MET cutpoints. TDEE as well as EEE increased significantly with higher training volume, while no difference in NEAT occurred. Further, significantly less time was spent in sedentary activities during the high-volume week. These results suggest that highly trained athletes do not compensate for increased training volume and reduce sedentary activities to allow for more training time.  相似文献   

对运动性疲劳生理机制研究的思考与展望     

王峰  李勤  刘建平  王驰 《军事体育进修学院学报》2013,(2):118-121

为运动训练性疲劳进一步研究提供启示,通过文献综述、逻辑分析等方法对国内外运动训练性疲劳的相关研究及存在的问题进行概述,同时,基于影响肌肉收缩控制链各环节功能的因素都是引起运动性疲劳原因,提出对运动性疲劳机制的研究需从微观和宏观两方面进行全面的整合及思考.  相似文献   

尼耳斯·玻尔原子理论的经验证据     

克劳 《科学文化评论》2013,(6):22-39

尼耳斯·玻尔关于原子结构的量子理论在1913—1925年占据原子和分子物理学主流地位。这一理论不仅在理论上有创新之处,在经验上也十分成功,这一点成为人们在早期接受该理论的主要原因。玻尔本人十分热衷于实验预测和实验检验,从未忘记一个好的物理学理论必须与实验结果一致。本文将概述玻尔原始理论的一些不太为人所知的相关实验,继而介绍他在1921—1923年提出的修正模型。玻尔雄心勃勃地希望在此模型中能够用元素的电子组态来解释周期系。在本文结尾部分,笔者将简述玻尔轨道原子模型向基于海森伯量子力学的新原子理论的过渡。  相似文献   

南通市售鲫鱼中重金属含量的分析检测     

周雷  胡鑫鑫  甘钊生  梁志 《黑龙江科技信息》2013,(26):70-70

鲫鱼样品经消解处理,采用原子吸收光谱法测定南通市售鲫鱼中肉、鳃和内脏3个组织器官内Cd、Cr、Cu、Pb、Zn六种元素的含量。检测结果显示:鱼内脏和鳃中的重金属含量高于鱼肉;所检测鱼中Cu、Zn含量较高,Cd、Cr、Pb含量较低;鱼肉中测重金属含量均低于国家食品限定量。  相似文献