Photoelectrocatalytic Property of Titanium Based TiO_2 Nanotube Array Electrode

应用电化学阳极氧化法在纯TI基底上制备高度有序的TIO2纳米管阵列,考察了TI/TIO2光阳极的光电化学响应。以苯酚溶液为目标污染物,研究TI/TIO2电极的光电催化性能,并与光催化性能进行比较。结果表明,该电极光电催化性能优于光催化性能,施加0.6V电压时,光电催化性能最好。电化学阻抗谱分析显示,光电催化和光催化降解过程的速控步骤均为表面反应步骤,外加偏压减小了界面电荷转移阻抗,提高了光生载流子的分离效率。TiO2 nanotube arrays were prepared by the electrochemical anodization on pure Ti surfaces,and their photoelectrochemical activity was examined.The photoelectrocatalytic property of Ti/TiO2 electrode was evaluated by the degradation of phenol aqueous solution and compared with its photocatalytic performance.The results demonstrated that the photoelectrocatalytic degradation rate of phenol solution for Ti/TiO2 electrode was higher than its photocatalytic degradation rate.The highest photoelectrocatalytic level could be achieved when the bias potential of 0.6V was applied on the Ti/TiO2 electrode.The results of EIS analyses revealed that the surface reaction step was the only rate limiting step either for the photocatalytic process or for the photoelectrocatalytic process.The extra bias potential could decrease the values of the electron-transfer resistance and increase the separation efficiency of photogenerated electron-hole pairs.福建省自然科学基金(No.U0750015);福建省科技计划重点课题(No.2007H0031);厦门市科技计划(No.3502Z20073004)资助项

Electrohydrodynamic printing for head with retractable needle

设计了一种新型的基于电液动力学的喷头,该喷头内含一个可伸缩的针尖。由这种喷头组成的喷印系统,在不同的条件下可以产生离散的点和珠状结构两种喷射模式。结果表明:溶液浓度是区分这两种喷射模式的关键因素。当喷射溶液的浓度比较低时,喷印系统喷射出离散的圆点;当较高时,喷射出珠状结构。其珠状结构中珠子的直径随着系统供液速率的增加而变大,随着PEO溶液浓度的提高和针尖频率的增加而减小。改变收集板的移动速度,可以改变喷射沉积物形态,且该系统的喷射频率与可伸缩针尖的运动频率之间有很好的线性相关性。A novel electrohydrodynamic printing system with a retractable needle was designed,by which both ejection modes of dots and bead-on-string structures can be produced.Experimental results show that solution concentration is the key element to define the ejection mode.Dots can be obtained for lower solution concentration,otherwise bead-on-string structures would be produced.the diameter of deposition dots increases with the increasing of supply rate,and decreases with the increasing of PEO solution concentration and the frequency increasing of needle.By changing the speed of collector,different morphologies of depositions can be obtained.In addition,the deposition frequency has a close relationship with the retractable frequency of needle.中央高校基本科研业务费专项资金(2010121039);国家自然科学基金(51035002;50875222

Photoelectrocatalytic Property of Titanium Based TiO2 Nanotube Array Electrode

TiO2 nanotube arrays were prepared by the electrochemical anodization on pure Ti surfaces, and their photoelectrochemical activity was examined. The photoelectrocatalytic property of Ti/TiO2 electrode was evaluated by the degradation of phenol aqueous solution and compared with its photocatalytic performance. The results demonstrated that the photoelectrocatalytic degradation rate of phenol solution for Ti/TiO2 electrode was higher than its photocatalytic degradation rate. The highest photoelectrocatalytic level could be achieved when the bias potential of 0.6 V was applied on the Ti/TiO2 electrode. The results of EIS analyses revealed that the surface reaction step was the only rate limiting step either for the photocatalytic process or for the photoelectrocatalytic process. The extra bias potential could decrease the values of the electron-transfer resistance and increase the separation efficiency of photogenerated electron-hole pairs

Controlling Reversible Expansion of Li2O2 Formation and Decomposition by Modifying Electrolyte in Li-O2 Batteries

锂空电池分别使用空气中的氧气和金属锂作为正负极活性材料，具有极高的能量密度。但是，这一体系尚不能实现商业化的应用，其中一些关键问题未能解决。由于其正极活性材料是气体，使得电化学反应涉及气-液-固三相界面，电极过程十分复杂。与其它二次电池相比，空气电极需要考虑结构因素和催化因素。不仅要改善氧气电化学反应的动力学迟缓问题，还要考虑放电产物的驻留空间问题。董全峰教授课题组在前期开展了基于空气电极固相表面电催化研究，并结合电极结构方面的问题，构筑了有利于氧气发生反应的仿生开放式结构电极。 该研究工作主要由化学化工学院2015级iChEM直博生林晓东（第一作者）在董全峰教授、郑明森副教授和龚磊副教授的共同指导下完成，理论计算由袁汝明助理教授（共同第一作者）完成，曹勇、丁晓兵、蔡森荣、韩博闻等学生参与了部分工作。周志有教授和洪宇浩博士生在电化学微分质谱方面给予大力的帮助与支持。【Abstract】The aprotic lithium-oxygen (Li-O2) battery has attracted worldwide attention because of its ultrahigh theoretical energy density. However, its practical application is critically hindered by cathode passivation, large polarization, and severe parasitic reactions. Here, we demonstrate an originally designed Ru(Ⅱ) polypyridyl complex (RuPC) though which the reversible expansion of Li2O2 formation and decomposition can be achieved in Li-O2 batteries. Experimental and theoretical results revealed that the RuPC can not only expand the formation of Li2O2 in electrolyte but also suppress the reactivity of LiO2 intermediate during discharge, thus alleviating the cathode passivation and parasitic reactions significantly. In addition, an initial delithiation pathway can be achieved when charging in turn; thus, the Li2O2 products can be decomposed reversibly with a low overpotential. Consequently, the RuPC-catalyzed Li-O2 batteries exhibited a high discharge capacity, a low charge overpotential, and an ultralong cycle life. This work provides an alternative way of designing the soluble organic catalysts for metal-O2 batteries.This work was supported by the National 973 Program (2015CB251102), the Key Project of National Natural Science Foundation of China (21673196, 21621091, 21703186, 21773192),and the Fundamental Research Funds for the Central Universities (20720150042,20720150043). The authors thank Prof. Eric Meggers at Philipps-Univeristaet Marburg for his discussion about the synthesis of RuPC complex; Prof. Gang Fu at Xiamen University for his instructive discussions in DFT calculations; Lajia Yu and Dandan Tao at Xiamen University for their assistance in EPR experiments and UV-Vis spectroscopy experiments, respectively; and Yu Gu and Tao Wang at Xiamen University for their discussions in XPS results and CV data,respectively. 该工作得到科技部重大基础研究计划（项目批准号：2015CB251102）、国家自然科学基金（项目批准号：21673196、21621091、21703186、21773192）和中央高校基本科研业务费专项资金（项目批准号：20720150042、20720150043）的资助。 此外，感谢傅钢教授在理论计算方面的讨论和建议，Eric Meggers教授在配合物合成上的讨论，泉州师范学院吴启辉教授和化学化工学院谷宇博士生在X射线光电子能谱方面的帮助，于腊佳老师在电子顺磁共振实验上的帮助，陶丹丹博士生在紫外可见光谱测试上的帮助以及王韬博士生在循环伏安方面的讨论

Damage to mangroves from extreme cold in early 2008 in southern China

通讯作者Author for correspondence (E-mail: [email protected])2008年初,我国南方19个省经历了50年一遇的持续低温雨雪冰冻天气。极端气候对华南沿海各省的红树林区造成不同程度的危害。2008年3月,在我国南方各省红树林区的10个代表性地点,对这次寒害造成的红树植物伤害程度进行了系统的调查。结果表明:冬季低温对红树林的影响极为显著,特别是在低纬度的海南、广西和广东湛江,由于极端低温正值夜间退潮,对红树林的影响更为显著;在纬度较高的福建,本地红树种类秋茄(Kandelia obovata)、桐花树(Aegiceras corniculatum)和白骨壤(Avicennia marina)及引种的木榄(Bruguiera gymnorrhiza)等,由于长期适应于冬季较低的气温或在种植前经过抗寒锻炼,具有较强的抗寒能力。各地主要红树植物中,广布种秋茄、桐花树和白骨壤最为耐寒,其耐寒性均大于红树科的木榄、海莲(Bruguiera sexangula)和红海榄(Rhizophora stylosa)。海桑(Sonneratia caseolaris)对温度的敏感性最强,抗寒能力最低,因此,即使在其原产地海南也受到较为严重的寒害,在纬度更高的引种地出现大面积受害甚至全部死亡,而从孟加拉国引种的无瓣海桑(Sonneratia apetala)却显示出一定的抗寒能力。同一地点的红树植物幼苗的抗寒能力低于大树。此次寒害也造成了苗圃场的种苗大量死亡,成熟的植株提前落花落果,这势必会影响后继一两年内红树林的自然更新和人工造林。因此,在未来红树林造林或人工引种中,一定要考虑到红树植物的抗寒能力。国家自然科学基金(30671646和30700092);厦门大学“闽江学者”启动基

The effect of stimuli synchronization on time perception and the mechanism

时间知觉，对生物的生存至关重要。已有大量研究证实，空间线索会对时间知觉产生影响。在本研究中，我们研究时间线索，即刺激之间的同步性，对亚秒级时间知觉的影响。 研究一探讨刺激的同步性是否会影响时间知觉，及在内部时钟模型中关于结果的解释。研究使用的刺激由100个Gabor构成，每个Gabor沿着垂直于朝向的两个方向做来回运动。Gabor的运动由熵值和相关值定义。熵值是指其运动方向改变的概率，相关值是指所有Gabor在改变运动方向的同步程度。实验一中，19个被试完成四个刺激条件的时长判断任务。结果发现，同步刺激相比随机刺激，会被知觉得更短（差值约70ms） 。这种时间压缩效应并非由被知觉到的速度所中介（实验二） 。改变刺激呈现时长发现，不同时长条件之间的效应有显著差异（实验三） 。另外我们发现在对刺激和刺激消失的识别任务上，简单反应时没有显著的差异，提示时间知觉的压缩效应不是反应时之间的差异（实验四） 。 研究二探讨刺激的同步性跟空间线索在时间知觉任务上是否有交互作用。 结果发现时间压缩效应仅发生在低空间频率条件下。 同步性信息与速度有交互作用，但与数量、密度和对比度没有交互作用。 结果提示同步的刺激和不同步的刺激在时间知觉任务中表现有稳定的差异。此差异不能通过内部时钟模型合理解释。刺激同步性与速度，空间频率在时间知觉中存在交互作用</p

Homing Research and Realization of Wire Bending Robot

介绍了一种在数控加工中实现高精度机械回零的方法,其为基于PMAC开放式运动控制卡回零模块,并结合非接触式接近开关限位来完成的,通过在弯丝机器人的应用表明,该方法显著提高各数控轴的自动回零精度,同时也提高了零件加工精度,保证了产品的生产效率和生产成本。The paper introduced a new method which can realize home in CNC manufacturing precisely.It was achieved by combining with PMAC(Open movement controller) and non-contact proximity switch.This method not only significantly improved the operation precision of mechanical returning home,but also enhanced the machining accuracy,production efficiency and products quality.The method had been successfully applied to wire bending robot

Transcranial electrical stimulation and visual function modulation

经颅电刺激(Transcranial Electrical Stimulation,TES)通过电极将特定模式的低强度电流作用于大脑头皮以调控皮层活动,是一种非侵入、无创的神经刺激方法。根据刺激电流的模式的不同,TES分为经颅直流电刺激(t DCS),经颅交流电刺激(t ACS)和经颅随机电刺激(t RNS)。TES能对视功能诸如光幻视阈值、视野、对比敏感度、视知觉运动等进行一定程度上的调控,并且能够与传统的视觉知觉学习训练相结合以调控视觉功能。对于不同的视觉功能,不同的TES参数和模式的调控效果有所不同。</p

经颅电刺激与视功能调控

经颅电刺激(Transcranial Electrical Stimulation,TES)通过电极将特定模式的低强度电流作用于大脑头皮以调控皮层活动,是一种非侵入、无创的神经刺激方法。根据刺激电流的模式的不同,TES分为经颅直流电刺激(t DCS),经颅交流电刺激(t ACS)和经颅随机电刺激(t RNS)。TES能对视功能诸如光幻视阈值、视野、对比敏感度、视知觉运动等进行一定程度上的调控,并且能够与传统的视觉知觉学习训练相结合以调控视觉功能。对于不同的视觉功能,不同的TES参数和模式的调控效果有所不同