首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 125 毫秒
1.
基于碳纳米管的超级电容器   总被引:34,自引:0,他引:34  
通过不同工艺手制造备了碳纳米管的固体电极。以这种电极为基础的超级电容器的体积比电容达到了107F/cm^3,证明这种电极是超级电容器的理想候选材料。在碳纳米管表面沉积RuO2.xH2O,制备出碳纳米管和RuO2.xH2O的复合电极。采用复合电极的电容器的比电容较之于纯碳纳米管电极显著提高。  相似文献   

2.
以复合型活性炭为原料,通过拌浆、涂布、干燥及老化检测等工艺制备出正负电极厚度不同的方形双电层电容器,通过加速循环寿命测试分析了不同电极厚度双电层电容器体积比电容与内阻等方面的变化.结果表明:长时间的加速循环寿命测试会导致电容器隔膜变黄、变黑;当正极厚度大于负极时,双电层电容器具有更加稳定的电化学性能和更小的膨胀率.此外,在电容器负极厚度一定、电极平衡系数为0.20时,双电层电容器的综合性能最佳.  相似文献   

3.
建立一种阵列电极技术,通过测量不同时空的微电极腐蚀电位、电偶电流及其动态变化,研究了在腐蚀介质作用下,混凝土中钢筋腐蚀发生、发展早期过程阳极区和阴极区分布特征,探讨了钢筋腐蚀过程宏观腐蚀电池与微观腐蚀电池的相互作用机制.结果表明,伴随着点腐蚀的发生、发展过程,在钢筋/混凝土界面宏观腐蚀电池的作用明显,宏观腐蚀电池电流分布与腐蚀电位有密切的对应关系.混凝土中钢筋腐蚀过程总是存在着宏观腐蚀电池和微观腐蚀电池,二者密切相关、相互作用,对钢筋局部腐蚀的发生、发展过程有重要影响.  相似文献   

4.
兼具高功率密度与高能量密度的储电技术是电化学储能领域的终极目标,寻找新型储电体系成为实现这一目标的重要策略.超级电容电池融合二次电池和超级电容器的优势,实现高功率密度和高能量密度在同一时空的统一.作为关键电极材料,超级电容电池型电极材料具有快速的电子和离子传输通道,在热力学、动力学允许条件下实现最大化利用氧化还原活性阳离子.目前开发的胶体离子超级电容电池能量密度可以达到350 Wh/kg,功率密度达到2 kW/kg.超级电容电池储电设备特别适合应用于脉冲电源、电磁弹射、能量回收、启停电源等领域.  相似文献   

5.
电容压力微传感器数值分析   总被引:2,自引:0,他引:2  
用伪谱算法对电容压力微传感器极板膜在均匀载荷条件下的弯曲行为作了数值模拟, 叙述了伪谱算法原理, 并将其用于微传感器的载荷与电容关系分析. 对于非接触式电容压力微传感器, 只有在小载荷(引起的最大垂向位移甚小于极板膜厚度)的条件下, 才可以忽略作用于极板膜的中平面的张力, 此时, 微传感器的电容与载荷之间呈线性关系. 当进一步增加载荷时, 两者的关系呈非线性, 电容随载荷的增大迅速增加. 对于接触式电容压力微传感器, 给出了接触半径的计算公式, 数值计算了载荷与电容关系曲线, 为压力微传感器分析和设计提供了理论依据.  相似文献   

6.
唐子龙 《中国科学(E辑)》2008,38(9):1469-1477
针对材料腐蚀科学中数据源众多的特点及腐蚀信息挖掘的需要,提出了腐蚀科学通用数据模型及整合腐蚀信息系统的构想。根据各种数据源特征的分析,提出了统一腐蚀数据模型和接口界面的解决方案。分析单元腐蚀数据应具有完整,自备和相对独立等特征的原因;剖析了整合腐蚀信息系统中若干关键问题;勾画了腐蚀信息交换系统的基本架构和信息流动模式;分析了系统中各种角色及相互作用关系,数据和信息的生成和流向。最后从计算机科学的角度,探讨了实现整合腐蚀信息系统的途径。  相似文献   

7.
以NH_4VO_3为原料,通过180℃下水热反应和550℃下NH_3处理制备了多孔氮化钒(VN)纳米带气凝胶,并对多孔VN纳米带气凝胶的电化学性能进行了分析.SEM和TEM分析表明所制备的多孔VN纳米带的宽度为100~400 nm,孔尺寸为10~20 nm.电化学阻抗谱分析表明多孔VN纳米带气凝胶对I3.还原反应具有很高的催化活性,电荷迁跃电阻为1.36Ωcm~2.用多孔VN纳米带气凝胶电极组装的染料敏化太阳电池的光电转换效率为7.05%,与传统的Pt电极电池相近.循环伏安和恒流充放电实验表明多孔VN纳米带气凝胶具有较好的电容性能.当电流密度为0.5 A/g时,多孔VN纳米带气凝胶在2 mol/L KOH溶液中的比电容达到292.2 F/g.因此,所制备的多孔VN纳米带气凝胶可以作为高效的电极材料应用于染料敏化太阳电池对电极和超级电容器电极中.  相似文献   

8.
针对传统加工方法在加工非导电工程陶瓷时存在加工效率低、成本高以及加工表面质量差等缺点,本文提出了非导电工程陶瓷高能量电容高效电火花加工新方法,并进行了单脉冲放电试验研究,结果表明,该方法采用高电压大电容以及较高的放电能量,能够较大地提高材料去除效率,单次脉冲放电陶瓷去除量可达17.63mm3.对加工极性、峰值电压、电容、限流电阻、工具电极进给方式、工具电极截面积以及辅助电极厚度等参数对陶瓷蚀除坑体积、工具电极损耗以及辅助电极损耗等性能的影响进行了试验研究与理论分析,得到了相应的规律关系.采用扫描电子显微镜对单脉冲放电坑的微观形貌进行了观测.结果表明:放电坑表面呈溅射状,陶瓷主要以剥落方式去除,放电通道中心区域部分材料以熔化蒸发方式去除,且材料去除效果随着加工参数的增大而增强.  相似文献   

9.
将模糊理论应用于并联电容器的故障诊断中.针对其故障特点,建立了并联电容器典型故障诊断模型,研究了一种并联电容器故障模糊诊断系统.该系统采用人机界面,集数据采集、信号分析,征兆提取,故障诊断于一体,操作使用方便.实验结果表明,该系统可对并联电容器的典型故障进行有效识别,帮助维修人员确定故障,提高效益.  相似文献   

10.
基于连续函数的变分极值理论,从共形同轴线电容问题中提炼出基本三角形和任意三角形,由它们可以叠加成任意共形同轴线,同时进一步发展了微分三角形来解决任意曲线方程,导出了任意共形同轴线电容的变分解析闭式,从而比较彻底地解决了任意共形同轴线电容问题.文中给出了各种共形同轴线的实例,讨论了所提出方法的应用和解析闭式的准确性.  相似文献   

11.
Microbial corrosion of concrete   总被引:6,自引:0,他引:6  
Summary Sulphuric-acid-producing thiobacilli cause severe corrosion of concrete walls in sewage pipelines. The bacteria excrete sulphuric acid, which degrades carbonaceous binding material. Nitrifying organisms have been found in high cell numbers on historical sandstone buildings as well as on concrete buildings. The nitric acid, which is excreted by these organisms as metabolic end-product, also causes severe corrosion. The microorganisms are able to metabolize inorganic substances like ammonia and NO originating from air pollution.The natural process was remodelled by means of simulation experiments. It became evident that mineral-acid-producing bacteria play an important role in biodeterioration of building materials.  相似文献   

12.
根据所制备的开孔泡沫铝/环氧树脂复舍材料的结构特点,对其材料结构进行了合理的简化。在此基础上采用ANSYS/KS—DYNA软件对该材料的压缩力学行为进行有限元仿真分析;得出了该材料在压缩过程中的变形和失效过程以及应力-应变关系随其结构参数(泡沫铝孔径、泡沫铝相等密度)及应变率的变化规律。如上规律与已有文献的物理实验研究结果相一致,从而证明了该仿真方法的合理可行性,为泡沫铝孔洞填充复合材料的性能研究提供了一种新方法。  相似文献   

13.
钛合金及其表面处理的现状与展望   总被引:15,自引:0,他引:15  
钛合金具有抗腐蚀能力强、比强度高、中温性能稳定等一系列优点,另一方面,它也有对粘着磨损和微动磨损非常敏感,耐磨性差,易氧化,对聚合物、金属及陶瓷涂层附着力差等缺点,这些缺点的存在限制了它的进一步应用,为克服钛合金这些缺点采取了一些相应的表面处理对策与手段,如表面微弧氧化、表面合金化、离子注入表面改性等。研究表明在钛合金表面形成TiC、TiN、TiO、(TiAl)N等纳米级,复合,渗、镀、注入层今后仍然是钛合金表面处理的发展方向。  相似文献   

14.
Treatment of Ca2+-loaded mitochondria with both aluminum and tyramine results in a swelling of higher amplitude than with aluminum alone, while tyramine alone is ineffective. The phenomenon is accompanied by H2O2 production and thiol and pyridine nucleotide oxidation. Cyclosporin A, N-ethylmaleimide or dithioerythritol completely prevent these effects, while catalase exhibits a lower inhibition, pointing to the induction of the permeability transition (MPT) by an oxidative stress. Reactive oxygen species are generated by the interaction of aluminum with the inner membrane and the oxidation of tyramine by monoamine oxidase on the outer membrane. This different localization determines the oxidation of critical thiol groups located on both internal and external sides of pore-forming structures, resulting in MPT induction. The reduced effect by aluminum or the inefficacy by tyramine, when implied alone, can be attributable to the oxidation of thiol groups located only on the internal or external side, respectively. Ultrastructural observations show that aluminum plus tyramine induce the typical configuration of mitochondria that have undergone the MPT. Instead, with aluminum alone, the sensitive subpopulation, although swollen, preserves the outer membrane and shows an apparently orthodox configuration.  相似文献   

15.
Summary Anesthesia with a large dose of pentobarbital (55 mg/kg, i.p.) caused a sustained decrease in brain temperature (Tb), which was monitored with a probe placed in the midbrain reticular formation. The administration of TRH to the lateral ventricle antagonized this hypothermia. None of the acute surgeries examined in this paper (adrenal-demedullectomy, septal knife cuts, electrolytic lesions of the hypothalamus and midbrain knife cuts) had any essential effect on this antagonism by TRH. These results suggest that centrally-administered TRH exerts its effect on thermoregulation, at least in part, through brain structure(s) caudal to the midbrain.  相似文献   

16.
采用失重法、极化曲线法、交流阻抗法研究泛昔洛韦与十二烷基苯磺酸钠(SDBS)对黄铜在3.0%NaCl介质中的缓蚀作用。结果表明:当泛昔洛韦浓度为0.40g/L、SDBS浓度为0.35g/L时,其复配缓蚀效率达到93.5%。泛昔洛韦和SDBS对黄铜的缓蚀机理分析表明,泛昔洛韦在铜舍金表面通过物理与化学吸附共同作用形成保护膜,与SDBS发挥了极好的协同作用,阻碍Cl^-对铜的侵蚀,实现了对铜的高效保护。  相似文献   

17.
K Ishikawa  M Suzuki 《Experientia》1986,42(9):1029-1031
Anesthesia with a large dose of pentobarbital (55 mg/kg, i.p.) caused a sustained decrease in brain temperature (Tb), which was monitored with a probe placed in the midbrain reticular formation. The administration of TRH to the lateral ventricle antagonized this hypothermia. None of the acute surgeries examined in this paper (adrenal-demedullectomy, septal knife cuts, electrolytic lesions of the hypothalamus and midbrain knife cuts) had any essential effect on this antagonism by TRH. These results suggest that centrally-administered TRH exerts its effect on thermoregulation, at least in part, through brain structure(s) caudal to the midbrain.  相似文献   

18.
What is scientific progress? On Alexander Bird's epistemic account of scientific progress, an episode in science is progressive precisely when there is more scientific knowledge at the end of the episode than at the beginning. Using Bird's epistemic account as a foil, this paper develops an alternative understanding-based account on which an episode in science is progressive precisely when scientists grasp how to correctly explain or predict more aspects of the world at the end of the episode than at the beginning. This account is shown to be superior to the epistemic account by examining cases in which knowledge and understanding come apart. In these cases, it is argued that scientific progress matches increases in scientific understanding rather than accumulations of knowledge. In addition, considerations having to do with minimalist idealizations, pragmatic virtues, and epistemic value all favor this understanding-based account over its epistemic counterpart.  相似文献   

19.
Burn injury causes an immunosuppression associated with suppressed adaptive immune function. Dendritic cells (DCs) are APCs for which signaling via their Toll-like receptors (TLRs) induces their maturation and activation, which is essential for the adaptive immune response. In this study, we examined if burn injury alters the TLR activity of splenic DCs. After injury, we noticed that DC functions were impaired, characterized by a suppressed capacity to prime naive T cells when triggering the TLR4 signaling cascade using specific ligands (LPS or rHSP60). The observed perturbations on LPS-primed DCs isolated from burned mice exhibited significantly diminished IL-12p40 production and enhanced IL-10 secretion-associated impairment in mitogen-activated protein kinase activation. Interestingly, we observed a decrease of TLR4/MD-2 expression on the CD8α+ DC subset that persisted following LPS stimulation. The altered TLR4 expression on LPS-stimulated CD8α+ DCs was associated with reduced capacity to produce IL-12 after stimulation. Our results suggested that TLR4 reactivity on DCs, especially CD8α+ DCs, is disturbed after burn injury.  相似文献   

20.
Intranigral injection of picrotoxin in Rats induced contralateral rotation and stereotyped behaviour. These responses were significantly altered following neuroleptic treatment (haloperiod, pimozide) or ipsilateral striatal electrolytic destruction. The present results provide behavioural evidence for gamma-aminobutyric acid-mediated inhibition of the dopaminergic nigrostriatal pathway.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号