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排序方式: 共有813条查询结果,搜索用时 31 毫秒
21.
碳纳米管电极超大容量离子电容器交流阻抗特性 总被引:18,自引:0,他引:18
采用碳纳米管作为超大容量离子电容器的电极材料,应用交流阻抗频谱法,研究了超大容量离子电容器的频率响应特性.结果表明,用碳纳米管块作电极,超大容量离子电容器在频率250 mHz以下出现“电荷饱和”;而用活性炭块作电极, 超大容量离子电容器在频率为100 mHz时仍未出现“电荷饱和”,这说明碳纳米管电极超大容量离子电容器的频率响应特性优于活性炭电极超大容量离子电容器的频率响应特性.上述两类超大容量离子电容器的阻抗谱中均出现倾角约为45°的直线段,其相位角均远小于理想电容器的相位角90°. 相似文献
22.
23.
活性炭自溶液吸附锌(II)离子及其配合物 总被引:10,自引:0,他引:10
近年来,有人提出通过表面处理提高活性炭表面电荷,加强对无机离子吸附力等观点,但活性炭对无机离子的吸附活性点,表面含氧基团及配体对吸附的影响等重要问题仍众说纷经[1-4]为此,本文提出用氧化一负离子化法处理活性炭,以表面酸度表征表面含氧基团的量,探讨活性炭对Zn(Ⅱ)及其配合物的吸附特性.1试验(1)试验材料活性发由北京光华木材厂出品,分析纯.过20-30目,BET法测得比表面为1316m2·g-1.在2.5×10-2mlo·dm-3的NaNO3中,测得等电点pHIEP为7.75[5],元素含量(质量分数)为C(83.9%),N(0.07%),H(1… 相似文献
24.
ZHANG Xiaoping CHEN Shuixia ZENG Hanmin Department of Environmental Science Engineering South China University of Technology Guangzhou P. R. China Key Laboratory of Polymeric Composite & Functional Materials The Ministry of Education of China Materials Science Institute Zhongshan University 《Chinese Journal of Reactive Polymers》2002,(2)
1. INTRODUCTION Study on the deposition of metal ions on ACFs indicated that such a process consists of several consecutive steps [1]: (1) transfer of the solvated ions (metal ions) from the bulk solution to the proximity of the ACFs surface; (2) absorpt… 相似文献
25.
K. Wagner 《Angewandte Chemie (International ed. in English)》1970,9(1):50-54
Addition compounds of formic acid with tertiary organic bases in ratios higher than that required for salt formation (3:1 and 2:1 adducts) contain formic acid in a highly activated form. In particular, the 3:1 adducts of formic acid with trimethylamine and triethylamine are liquid reducing agents that are convenient to handle and are suitable for use in many selective reductions. These addition compounds have a surprisingly strong reducing action on sulfur dioxide, which is rapidly converted, even at low concentrations, into crystalline rhombic sulfur. Sulfones and polysulfones can be prepared in good yields by three-component reactions from activated formic acid, sulfur dioxide, and polarized vinyl compounds. 相似文献
26.
ADSORPTION CAPACITY OF ACTIVATED CARBON FIBER FABRIC IN CYANIDE LEACHING LIQUOR OF GOLD ORES 总被引:1,自引:0,他引:1
LIU Xiaozhen Department of Chemical Engineering Shanghai Institute of Technology Shanghai China 《Chinese Journal of Reactive Polymers》2002,(1)
1. INTRODUCTION Reclamation of gold in liquid of gold with activated carbon fiber (ACF) is reported. ACF possessed numerous advantages, such as high adsorption capacity, great adsorption rate and high recovery of gold. It was generally considered tha… 相似文献
27.
In this study, a rapid pre-concentration procedure, which employs powdered activated carbon as a clean-up and pre-concentration material, is described for the gas chromatographic analysis of N-nitrosodiethylamine (NDEA) and N-nitrosodimethylamine (NDMA) in aqueous solutions. It was found that powdered activated carbon is suitable for the adsorption of volatile N-nitrosamine compounds from aqueous solutions. Adsorption efficiency with spiked beer samples (alcohol content 5% v/v) was found to be 80.5% (NDMA) and 89.4% (NDEA) and recovery of extraction from activated carbon was calculated as 82.1% (NDMA) and 89.7% (NDEA), respectively. The effect of 100µgmL–1 of tannic acid on the adsorption was also studied, and no significant effect on the adsorption and extraction of volatile N-nitrosamine compounds was found. 相似文献
28.
A mild and efficient two-step synthesis of a polystyrene thiol resin is reported. Firstly, a polystyrene resin was reacted with an activated sulfoxide to afford the resin bound bis-(2-methoxy-carbonylethyl)-sulfonium trifluoromethanesulfonate. Smooth β-elimination based dealkylations afforded the polystyrene thiol resin with good and controlled loading. Its reactivity was assessed through a derivatisation step. 相似文献
29.
《Electroanalysis》2004,16(21):1763-1770
The electrochemical behavior of the nitrofuran antibiotics nitrofurantoin (NFA) and nitrofurazone (NFZ), as well as the related nitroimidazole drug, metronidazole (MNZ) at electrochemically activated carbon fibre microelectrodes (CFMEs) is reported. These nitrofurans have been widely used in the form of feed additives for the treatment of gastrointestinal infections in cattle, pigs and poultry. Electrochemical activation of CFMEs by repetitive square‐wave (SW) voltammetric scans between 0.0 and +2.6 V, produced an unexpected high cathodic response from these compounds. This is attributed to the increase of the carbon fibre surface area due to its fracture and the appearance of deep fissures along the main fibre axis. Penetration of the nitroderivative compounds into the micro‐channels of the activated fibres was profited to develop a sensitive and selective method for NFA based on stripping SW voltammetry. The metabolite of NFA, 1‐aminohydantoin (AHD), did not exhibit cathodic response in the potential range between ?0.9 and +0.1 V. However, AHD gave a SW oxidation signal at activated CFMEs, with a potential of +0.95 V, which did not appear at non‐activated microelectrodes. Based on this finding, the simultaneous determination of NFA and AHD was performed by amperometry using two activated CFMEs in a parallel configuration connected to a multichannel detector. This methodology was also used to carry out degradation studies of NFA in acidic and basic media under photodegradation or thermal degradation conditions. 相似文献
30.
X-ray microtomography coupled with image analysis was used to quantify the adsorption of vapours on activated carbon beds.
This technique was tested using three different challenges: CCl4, water vapour and a mixture of water- and organic vapour. It is shown that the used technique allows determining the adsorption
front progress in the case of organic vapour and mixture of water and organic vapour whereas the existence of this front was
not so obvious in the case of water vapour. Experimental results obtained for organic vapours were interpreted on the basis
of the Wheeler-Jonas equation: a good agreement was found between experimental and theoretical breakthrough times. 相似文献