J.Koh
,
B.Kim
材料科学技术（英文）
We present a brief review about recent results regarding carbon nanotube (CNT)-based chemical and biomole-cular sensors. For the fabrication of CNT-based sensors, devices containing CNT channels between two metal electrodes are first fabricated usually via chemical vapor deposition (CVD) or “surface programmed assembly” method. Then, the CNT surfaces are often functionalized to enhance the selectivity of the sensors. Using this process, highly-sensitive CNT-based sensors can be fabricated for the selective detection of various chemical and biological molecules such as hydrogen, ammonia, carbon monoxide, chlorine gas, DNA, glucose, alcohol, and proteins.
关键词:
Chemical vapour deposition
,
vapour
,
deposition
,
carbon
,
nanotu
Z. Sun
,
S.L. Zheng
,
Y. Zhang
,
null
,
null
,
null
,
null
,
null
,
null
,
null
,
null
,
null
,
null
,
null
,
null
,
null
,
null
金属学报(英文版)
Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.
关键词:
chromite
,
null
,
null
,
null
Electrochemistry Communications
The feasibility of employing aluminum in KOH ethanol solution as a battery anode system is discussed. Weight loss measurement showed that its corrosion rate is low enough to be used in sealed batteries. Through anodic polarization, EIS and galvanostatic discharge, it was found that Al can keep electrochemical activity in a wide potential range in this system, and its discharge mechanism is similar to that of Al in aqueous solution. The discharge potential increases rapidly after a period of time, which may be caused by the discharge products deposited on the electrode surface. (C) 2003 Published by Elsevier B.V.
关键词:
pure aluminum;KOH ethanol solution;electrochemical performance;alkaline-solution
Physical Review B
The Hamiltonian for a four-sublattice Heisenberg ferrimagnet or ferromagnet with different exchange constants (J(ab) = J(cd) not equal J(bc) = J(da)) was established. An extended Bogoliubov transformation was developed by solving an equation group, consisting of 20 equations and 20 unknowns. The procedure for solving the equation group was carried out by introducing a simple way of reducing the numbers of the equations and the unknowns. The spin-wave spectra in the present system have been determined by performing the standard Holstein-Primakoff transformation and the Bogoliubov one. It has been found that the spin-wave spectra of the present system depend on the exchange constants and that the degeneracy of the spin-wave spectra remains. The results for a special case (J(ab) = J(bc)) i.e., an antiferromagnet are discussed briefly. The spin-wave spectra of the four-sublattice Heisenberg antiferromagnet are found to be degenerative also and they are linear in k for small k.
关键词:
model
Acta Chimica Sinica
The stability of K2FeO4 in dilute KOH solution with initial pH value from 8.0 to 13.0 was studied in detail by spectrophotometry method in this paper. The decomposition rate of aqueous solution of K2FeO4 is basically regulated by its concentration, pH and the decomposed product FeOOH that can catalyze the decomposition of K2FeO4. The increase of HO- concentration can improve the stability of K2FeO4 by decreasing the collision frequency between FeO42- ions. However, when the concentration of HO- reaches a certain value, the decomposition product FeOOH is easily produced. FeOOH can catalyze the decomposition of K2FeO4. It was found that K2FeO4 is the most stable in the pH region of 10.0 similar to 11.0 and the decomposition rate of K2FeO4 is in the first order in the initial period. The decomposition rule of K2FeO4 along with its concentration in KOH solution is related with the initial pH of the solution.
关键词:
K2FeO4;stability;spectrophotometry method;electrochemical characteristics;ferrate(vi) ion;electrode;battery
Y.G. Cao
,
X.Y. Sun
金属学报(英文版)
J-integral and crack opening displacement δ(COD) were important parameters for characterization of fractures in engineering materials. The relationship between J-integral and COD has been investigated for a long time and was enerally represented as J = m σyδ, where σy is the yield strength and m is a function of specimen geometry and material properties. To determine the value of m, extensive studies and experiments have been performed. The method that used the fracture-surface topography analysis (FRASTA) for determining J-integral from fracture surfaces of materials was introduced. On the basis of the relationship between COD and fracture surface average profile, the relationship between J-integral and COD was deduced and compared with the generally used equation. The method was experimentally confirmed to be able to provide a new way to determine the relationship between J-integral and COD.
关键词:
FRASTA
,
null
,
null
仲兆平
,
张居兵
,
郭厚焜
,
付宗明
,
肖健敏
工程热物理学报
本文使用KOH活化竹子制备DCFC用活性炭，考察了活化温度、活化时间和碱炭比对活性炭比表面积影响，采用镍负载以降低活性炭的电阻率并用HN03浸渍来实现活性炭表面改性和除灰，最后在DCFC阳极半电池中检验了活性炭的性能。结果表明：活性炭制备有如下的最佳工况，活化温度为800℃、活化时间为1h、碱炭比为3、镍负载量为2％、负载温度为900℃、保温时间为2h、HN03浸渍浓度为4mol·L^-1，此时制备的活性炭比表面积为2295m2·g^-1、电阻率为6963μΩ·m、灰分含量为358％；竹子活性炭在半电池中的性能优于活性炭纤维和石罨。
关键词:
直接碳燃料电池
,
活性炭
,
比表面积
,
电阻率
,
含氧官能团
王晓波
,
全风美
,
姜云波
,
李盛和
,
谢志强
,
杨建
表面技术
在微弧氧化电解液中引入了KOH添加剂,并在镁合金表面制备了陶瓷膜层,研究了KOH浓度对微弧氧化过程中的膜层生长及膜层耐腐蚀性能的影响.结果表明:在镁合金微弧氧化电解液中引入KOH添加剂可以有效降低微弧氧化过程的起弧电压和工作电压,但是KOH浓度过高会使起弧电压增大;KOH的引入会使膜层中的大尺寸孔隙数目减少,孔隙率提高.为了得到较高的膜层生长速率和较好的耐蚀性,电解液中的KOH剂量以1～3 g/L为宜.
关键词:
KOH
,
微弧氧化
,
耐蚀性
