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1.
杨裕生 《电化学》2020,26(4):443
本文回顾了22年来作者的电化学储能研究活动,共分三个部分. 第一部分叙述高比能量、高比功率储能器件研究,包括锂硫电池研究(硫复合正极材料、锂硫电池制作、锂硼合金作为锂硫电池负极、硫-锂离子电池新体系)、超级电容器研究(超级活性炭、以酚醛树脂为原料制备电容炭、碳纳米管阵列中寄生准电容储能材料、氧化镍干凝胶准电容储能材料、归纳出电容炭材料的性能要求、电容器研制、确定“第四类”超级电容器)、锂离子电池研究(锂离子电池与可再生燃料电池的对决、双变价元素正极材料、磷酸钴锂正极材料、高功率锂离子电池的制作). 第二部分叙述规模储能电池研究,包括液流电池新体系研究(蓄电与电化学合成的双功能液流电池、全金属化合物单液流电池、有机化合物正极的单液流电池)、致力于振兴铅酸电池(推广铅蓄电池新技术、铅炭电池的研究、铅酸电池新型板栅的研究),储能电池(站)的经济效益计算方法. 第三部分叙述电动汽车发展路线研究,包括氢能燃料电池电动汽车、纯电动汽车与混合动力汽车、对我国电动汽车发展路线的建议、力争电动汽车补贴的合理化、坚守电动汽车“节能减排”宗旨、提出“发电直驱电动车”. 最后的结束语谈了三点感悟.  相似文献   

2.
In this work, we report that 2-cyano-2-phenylpropanoic acid and its p-Cl, p-CH3 and p-OCH3 derivatives can be used as chemical fuels to control the geometry of the calix[4]arene scaffold in its cone conformation. It is shown that, under the action of the fuel, the cone calix[4]arene platform assumes a “locked” shape with two opposite aromatic rings strongly convergent and the other two strongly divergent (“pinched cone” conformation). Only when the fuel is exhausted, the cone calix[4]arene scaffold returns to its resting, “unlocked” shape. Remarkably, the duration of the “locked” state can be controlled at will by varying the fuel structure or amount. A kinetic study of the process shows that the consume of the fuel is catalyzed by the “unlocked” calixarene that behaves as an autocatalyst for its own production. A mechanism is proposed for the reaction of fuel consumption.  相似文献   

3.
To explore the effects of microenvironmental adjustments on fluorescence, a pH-sensitive nano-composite system based on fluorescence resonance energy transfer (FRET) was constructed. The model system included a modified triblock copolymer (polyhistidine-b-polyethylene glycol-b-polycaprolactone) and gold nanoparticles. A near-infrared dye was used as the donor, and spectrally matched gold nanorods, attached after C-terminus modification with α-lipoic acid, were used as the receptor to realize control of the FRET effect over the fluorescence intensity for two polymer configurational changes (i.e., “folded” and “stretched” states) in response to pH. After synthesis and characterization, we investigated the self-assembly behavior of the system. Analysis by quartz crystal microbalance revealed the pH sensitivity of the polymer, which exhibited “folding” and “stretching” states with changes in pH, providing a structural basis for the FRET effect. Fluorescence spectrophotometry investigations also revealed the regulatory impact of the assembled system on fluorescence.  相似文献   

4.
燃料电池汽车被认为是能源和交通领域的新方向之一,而目前氢源问题已成为其商业化的技术瓶颈。本文从国内外燃料电池汽车的发展现状出发,结合国外对燃料电池汽车氢源选择的评估和预测,及国内863计划“燃料电池汽车氢源基础设施工程前期研究”项目的研究结论,对我国燃料电池汽车的技术发展和商业化进程进行了预测。  相似文献   

5.
An electrochemical three component cascade phosphorylation reaction of various heteroatoms-containing nucleophiles including carbazoles, indoles, phenols, alcohols, and thiols with Ph2PH has been established. Electricity is used as the “traceless” oxidant and water and air are utilized as the “green” oxygen source. All kinds of structurally diverse organophosphorus compounds with P(O)-N/P(O)-O/P(O)-S bonds are assembled in moderate to excellent yields (three categories of phosphorylation products, 50 examples, up to 97 % yield). A tentative free radical course is put forward to rationalize the reaction procedure.  相似文献   

6.
Polyelectrolyte multilayers assembled from hyaluronic acid (HA) and poly‐l ‐lysine (PLL) are most widely studied showing excellent reservoir characteristics to host molecules of diverse nature; however, thick (HA/PLL)n films are often found cell repellent. By a systematic study of the adhesion and proliferation of various cells as a function of bilayer number “n” a correlation with the mechanical and chemical properties of films is developed. The following cell lines have been studied: mouse 3T3 and L929 fibroblasts, human foreskin primary fibroblasts VH‐Fib, human embryonic kidney HEK‐293, human bone cell line U‐2‐OS, Chinese hamster ovary CHO‐K and mouse embryonic stem cells. All cells adhere and spread well in a narrow “cell‐friendly” window identify in the range of n = 12–15. At n < 12, the film is inhomogeneous and at n > 15, the film is cell repellent for all cell lines. Cellular adhesion correlates with the mechanical properties of the films showing that softer films at higher “n” number exhibiting a significant decrease of the Young's modulus below 100 kPa are weakly adherent to cells. This trend cannot be reversed even by coating a strong cell‐adhesive protein fibronectin onto the film. This indicates that mechanical cues plays a major role for cell behavior, also in respect to biochemical ones.  相似文献   

7.
Non-degradated mineral-oils like gasoline, solvent naphtha, diesel fuel, fuel and lubricating oils provide a characteristic fingerprint gas chromatogram. This visual classification, e.g. in solid wastes, is complicated due to the simultaneous presence of several mineral-oils. Therefore, a mathematical algorithm for the separation of gas chromatographic fingerprint of “single mixtures” of aliphatic hydrocarbons is developed. The technique ¶is essential for analysis of time-overlapping “single mixtures” of petroleum hydrocarbons (so-called “complex mixtures”) and it relies on the concentration-varying hydrocarbons during evaporation. It is possible to separate the data from the gas chromatogram of a “complex mixture” of hydrocarbons into the chromatograms of the pure “single mixtures” and to give their respective concentrations. A synthetic ?complex mixture” of kerosene, diesel fuel and lubricating oil is used to illustrate the method.  相似文献   

8.
Two amphiphilic regioisomers, 9‐AP (1‐[11‐(9‐anthracenylmethoxy)‐11‐oxoundecyl]pyridinium bromide), and 2‐AP (1‐[11‐(2‐anthracenyl methoxy)‐11‐oxoundecyl]pyridinium bromide), were synthesized and their assembly behaviors were studied. Due to the anisotropic features of the anthracene structure, different substituted positions on the anthracene ring lead 9‐AP and 2‐AP to adapt “shaver” and “spatula”‐like molecular shapes, respectively, which consequently dictate the structure of their final assemblies. While “shaver”‐shaped 9‐AP assembled into microsheets, driven by π–π interactions, “spatula”‐shaped 2‐AP assembled into microtubular structures, promoted primarily by charge‐transfer interactions.  相似文献   

9.
The membranes in direct methanol fuel cells must both conduct protons and serve as a barrier for methanol. Nafion, the most common fuel cell membrane, is an excellent conductor but a poor barrier. Polyvinyl alcohol pervaporation membranes are good methanol barriers but poor conductors. These and most other pervaporation membranes offer no significant advantages over Nafion in methanol fuel cell applications. However, polybenzimidazole membranes have demonstrated characteristics that suggest up to a 15-fold improvement in direct methanol fuel cells. This improvement may be due to an alternate form of proton conduction in which protons travel via a Grotthus or “hopping” mechanism.  相似文献   

10.
甘全全  徐洪峰  张茂峰 《催化学报》2007,28(10):900-904
将超级电容器材料聚苯胺引入电极催化剂中以缓冲燃料电池负载的变化.以硫酸为掺杂剂,将化学法合成的聚苯胺(PANI)与Pt/C超声分散混合,制成PANI-Pt/C催化剂.PANI-Pt/C的循环伏安测试和作为质子交换膜燃料电池阴极电催化剂的电池性能测试表明,PANI含量为10%时能够提高Pt/C催化剂对氧的还原动力学速度和燃料电池放电性能.电池在不同电流负载下的电压动态响应和对电池脉冲电流的动态响应以及PANI-Pt/C催化剂多电位电势阶跃计时电流测试显示,聚苯胺在催化剂中具有在瞬间电流负载时缓冲电池电压和电池大电流放电时平稳电压的作用.  相似文献   

11.
This paper describes the formation of catalytically active thin films of Pt, Pt/Au, and Pt/Ru on gold substrates stabilized by amine‐terminated polyamidoamine (PAMAM) dendrimers. A monolayer of dendrimer is initially self‐assembled on the gold substrate, which serves as a template for the growth of catalytically active thin films. As dendrimers contain tens to hundreds of functional groups at the periphery, the aggregate strength of the multidentate interactions with the gold substrate leads to the formation of robust films. The films were found to exhibit high catalytic activity for the oxidation of small hydrocarbons such as methanol. Such films offer versatility and scope for the design of effective electrocatalysts, especially in the context of microfuel cells and “dendrichips”; hence, they could find applications in the fields of sensors, fuel cells, and waste‐water treatment.  相似文献   

12.
In urban areas, due to their beneficial effects on the environment, electric vehicles, hybrid electric vehicles and fuel cell electric vehicles are an important factor for the improvement of traffic and more particularly for a healthier environment. We are quite rapidly reaching the end of the cheap oil era. This could happen around 2010 and is nowadays probably indicated by the steadily growing oil price. Therefore the need for alternative energy sources is growing and the competitiveness of alternatives against oil is becoming more and more realistic. Electric vehicles, hybrid electric vehicles and fuel cell electric vehicles are offering the best possibility for the use of new energy sources, because electricity can result from a transformation with high efficiency of these sources and is always used with the highest possible efficiency in systems with electric drives or components. Some basic considerations about the situation, today and in a mid and long-term perspective, are presented together with the infrastructure developments.  相似文献   

13.
Electrospun materials have been gaining great interest in the energy sector. Their tunability and robustness make them highly attractive, particularly for proton-exchange membrane fuel cell (PEMFC) electrodes. Conventional PEMFC electrodes, prepared by either spraying, painting, or slot-die coating, have not yet met the needs of large-scale PEMFC use. Electrospinning of fibrous materials has already shown great promise as an alternative methodology for electrode fabrication. Electrospinning has been used in fuel cell electrodes through two primary means: (1) segmented carbon or inorganic fibers to serve as precious metal catalyst support, and (2) high aspect ratio polymer/particle fibers to serve directly as the electrode. The use of electrospun fibrous electrodes has led to improved PEMFC durability and increased power output at low catalyst loadings, both of which are of paramount importance to large-scale commercialization of PEMFC electric vehicles.  相似文献   

14.
Direct methanol fuel cells for vehicular applications   总被引:3,自引:0,他引:3  
Dramatic technological advances for the proton exchange membrane fuel cell have focused attention on this technology for motor vehicles. The fuel cell vehicles (FCVs) have the potential to compete with the petroleum-fueled internal combustion engine vehicles (ICEVs) in cost and performance while effectively addressing air quality, energy insecurity, and global warming concerns. Methanol being a liquid can be easily transported and can be supplied from the existing network of oil company distribution sites. Recently, combining improved catalysts with fuel cell engineering, it has been possible to overcome some of the difficulties that have frustrated previous research and development efforts in realizing a commercially viable direct methanol fuel cell. Direct methanol fuel cells (DMFCs) with power densities between 0.2 and 0.4 W/cm2 at operational temperatures in the range 95–130 °C have been developed. These power densities are sufficient to suggest that stack construction is well worth while. This paper reviews recent advances and technical challenges in the field of DMFCs. Received: 27 May 1997 / Accepted: 25 November 1997  相似文献   

15.
刘惠平  卢冠忠 《无机化学学报》2011,27(10):2045-2052
以"乙酸乙酯(EA)-偏铝酸钠-水"体系在室温下合成了纳米膜组装介孔Al2O3。研究发现:合成反应时间、静置前搅拌时间、NaAlO2用量、EA用量及反应温度等对合成产物的形貌有影响;另外,与用商品γ-Al2O3制备的Pt/γ-Al2O3催化剂相比,纳米膜组装介孔Al2O3制备的Pt/Al2O3催化剂含有部分易被还原的PtOx物种。在硝基苯催化加氢反应中,用合成Al2O3为载体制备的Pt/Al2O3催化剂,比用商品γ-Al2O3制备的Pt/γ-Al2O3催化剂具有更好的催化活性。  相似文献   

16.
《化学:亚洲杂志》2017,12(19):2549-2553
The design of tunable dynamic self‐assembly of nanoparticles with switchable assembled dimensions and morphologies is a challenging goal whose realization is vital for the evolution of smart nanomaterials. Herein, we report on chitosan polymer as an effective supramolecular “glue” for aldehyde‐modified Au nanoparticles to reversibly modulate the states of self‐assembled nanocomposites. By simultaneous integration of dynamic covalent Schiff base interactions and noncovalent hydrogen bonds, the chitosan/Au nanocomposites could reversibly transform their assembled morphologies from one‐dimensional nanowires to three‐dimensional nanosponges in response to the variation of pH value. Moreover, the obtained nanosponges could be used as an efficient pH‐controlled cargo release system.  相似文献   

17.
Journal of Thermal Analysis and Calorimetry - The use of automotive air conditioning (AAC) nowadays is essential because of the hot climate and global warming. The AAC increases the overall fuel...  相似文献   

18.
张燕梅  方军  严格  庄永泽 《电化学》2011,17(1):73-79
以甲基丙烯酸二甲基氨基乙酯和甲基丙烯酸三氟乙酯为单体,经过自由基聚合反应、成膜和碱化3个步骤制备氢氧型的DMAEMA/TFMA聚合物阴离子交换膜,系统表征该聚合物膜的结构和性能.结果表明:室温下其电导率可达10-2 S.cm-1;该膜的甲醇渗透系数低于10-7 cm2.s-1;以该膜组装的单电池在室温下的最大功率密度为43.2 mW/cm2,在燃料电池中有良好的应用前景.  相似文献   

19.
In this work, chitin microspheres (NCM) having a nanofibrous architecture were constructed using a “bottom‐up” fabrication pathway. The chitin chains rapidly self‐assembled into nanofibers in NaOH/urea aqueous solution by a thermally induced method and subsequently formed weaved microspheres. The diameter of the chitin nanofibers and the size of the NCM were tunable by controlling the temperature and the processing parameters to be in the range from 26 to 55 nm and 3 to 130 μm, respectively. As a result of the nanofibrous surface and the inherent biocompatibility of chitin, cells could adhere to the chitin microspheres and showed a high attachment efficiency, indicating the great potential of the NCM for 3D cell microcarriers.  相似文献   

20.
本文综述了近年来车用燃料电池电催化的发展状况,分析了车用燃料电池电催化的发展趋势,重点介绍了大连化学物理研究所在燃料电池电催化方面的研究进展.指出车用燃料电池电催化的发展方向是提高现有铂基催化剂的活性,在保证车用燃料电池在变载等动态工况下的可靠性与寿命的前提下,应降低膜电极的贵金属铂用量,发展低铂/非铂电催化剂.针对车用燃料电池的使用条件,应发展抗燃料气与空气中杂质的电催化方法与抗腐蚀催化剂载体.从长远考虑,重点发展碱性聚合物膜燃料电池,拓展利于活化顺磁性氧的催化方法,有望摆脱车用燃料电池对铂催化剂的依赖.  相似文献   

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