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2000

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Full-Text Articles in Physical Sciences and Mathematics

Validation And Verification Of Formal Specifications In Object-Oriented Software Engineering, Steven A. Thomson Sep 2000

Validation And Verification Of Formal Specifications In Object-Oriented Software Engineering, Steven A. Thomson

Theses and Dissertations

The use of formal specifications allows for a software system to be defined with stringent mathematical semantics and syntax via such tools as propositional calculus and set theory. There are many perceived benefits garnered from formal specifications, such as a thorough and in-depth understanding of the domain and system being specified and a reduction in user requirement ambiguity. Probably the greatest benefit of formal specifications, and that which is least capitalized upon, is that mathematical proof procedures can be used to test and prove internal consistency and syntactic correctness in an effort to ensure comprehensive validation and verification (V&V). The …


Structural Relatedness Of Distinct Determinants Recognized By Monoclonal Antibody Tp25.99 On Ss2-Microglobulin-Associated And Ss2-Microglobulin-Free Hla Class I Heavy Chains, Smruti A. Desai, Xinhui Wang, Elvyra J. Noronha, Qinwei Zhou, Vera Rebmann, Hans Grosse-Wilde, Franklin J. Moy, Robert Powers, Soldano Ferrone Sep 2000

Structural Relatedness Of Distinct Determinants Recognized By Monoclonal Antibody Tp25.99 On Ss2-Microglobulin-Associated And Ss2-Microglobulin-Free Hla Class I Heavy Chains, Smruti A. Desai, Xinhui Wang, Elvyra J. Noronha, Qinwei Zhou, Vera Rebmann, Hans Grosse-Wilde, Franklin J. Moy, Robert Powers, Soldano Ferrone

Department of Chemistry: Faculty Publications

The association of HLA class I heavy chains with ß2-microglobulin (ß2m) changes their antigenic profile. As a result, Abs react with either ß2m-free or ß2m-associated HLA class I heavy chains. An exception to this rule is the mAb TP25.99, which reacts with both ß2m-associated and ß2m-free HLA class I heavy chains. The reactivity with ß2m-associated HLA class I heavy chains is mediated by a conformational determinant expressed on all HLA-A, -B, and -C Ags. This determinant has been mapped to amino acid residues 194–198 in the …


The Rr Lyrae Star V442 Herculis: An Extreme Case Of Light-Curve Modulation, Edward G. Schmidt, Kevin M. Lee Sep 2000

The Rr Lyrae Star V442 Herculis: An Extreme Case Of Light-Curve Modulation, Edward G. Schmidt, Kevin M. Lee

Edward Schmidt Publications

We have obtained photometric observations of the peculiar RR Lyrae star V442 Her during six observing seasons spanning an elapsed time of nearly 9 years. The period has undergone two large, abrupt changes in the past 5 years. Although light-curve modulation is fairly common among RR Lyrae stars, the modulation of the light curve of V442 Her is highly unusual for its large amplitude, long period, extreme alterations in light-curve shape, and large period changes.


A Science-Based Initiative To Manage Double-Crested Cormorant Damage To Southern Aquaculture, James F. Glahn, Mark E. Tobin, Bradley F. Blackwell Sep 2000

A Science-Based Initiative To Manage Double-Crested Cormorant Damage To Southern Aquaculture, James F. Glahn, Mark E. Tobin, Bradley F. Blackwell

United States Department of Agriculture Wildlife Services: Staff Publications

Aquaculture has expanded rapidly in the Southern United States during the past two decades, especially the cultivation of catfish, crawfish, and bait fish. These fish usually are cultivated on farms with extensive systems of large shallow ponds that are highly susceptible to predation by birds. Double-crested cormorants (Phalacrocorax auritus ), American white pelicans (Pelecanus erythrorhynchos ), wading birds (e.g., Ardea alba, Ardea herodius ), and scaup (Aythya spp. ) are among the birds most frequently implicated. Well-documented problems associated with cormorant predation on catfish farms have coincided with the increase of this industry and the rapid …


Community Support For Natural Resource Management. Future Frameworks: Future Needs, Fionnuala Frost, Wendy Dymond, Soil And Land Conservation Council Of Western Australia Sep 2000

Community Support For Natural Resource Management. Future Frameworks: Future Needs, Fionnuala Frost, Wendy Dymond, Soil And Land Conservation Council Of Western Australia

Natural resources published reports

A report prepared for the Soil and Land Conservation Council of Western Australia.

Emerging from the Decade of Landcare is growing recognition that regional and local community involvement is integral to the success of any natural resource management (NRM) outcome. It is integral for a number of reasons:

1. Community support provides the capacity to develop plans and strategies at local, regional scale which are owned by the community who review (technical recommendations, advice and information and adapt them to suit local need;

2. Community knowledge provides an important balance to research knowledge and State and regional level strategies and …


Agriculture Western Australia's Great Southern Agricultural Research Institute Katanning, Agriculture Western Australia Sep 2000

Agriculture Western Australia's Great Southern Agricultural Research Institute Katanning, Agriculture Western Australia

Natural resources published reports

Agriculture Western Australia's Great Southern Agricultural Research Institute has been established as a centre of excellence for research, development and extension into sustainable farming systems The. agency has a long association with the town of Katanning dating back to 1925 when the agency provided a general agricultural advisor.

The new Institute is strategically located in the heart of key sheep and cropping production areas with significant growth potential.

Its role is to stimulate the contribution of ideas from individuals, groups and organisations with an interest in research, development and extension relating to innovative, profitable and sustainable animal and cropping based …


Alpha Particle Emission From6he + 209bi , D. Lizcano, E. F. Aguilera, E. Martínez-Quiroz, J. J. Kolata, V. Guimarães, D. Peterson, P. Santi, R. White-Stevens, F. M. Nunes, F. D. Becchetti, M. Y. Lee, T. O'Donnell, P. A. Deyoung, M. Goupell, B. Hughey, A. Nowlin, Graham F. Peaslee Sep 2000

Alpha Particle Emission From6he + 209bi , D. Lizcano, E. F. Aguilera, E. Martínez-Quiroz, J. J. Kolata, V. Guimarães, D. Peterson, P. Santi, R. White-Stevens, F. M. Nunes, F. D. Becchetti, M. Y. Lee, T. O'Donnell, P. A. Deyoung, M. Goupell, B. Hughey, A. Nowlin, Graham F. Peaslee

Faculty Publications

In a recent experiment, we have for the first time studied near-barrier and sub-barrier fusion of the exotic "Borromean" nucleus 6He with 209Bi and found that the sub-barrier fusion of this system is exceptionally enhanced, implying a 20% reduction in the nominal fusion barrier. It was suggested that this striking effect might he due to coupling to positive Q-value neutron transfer channels, leading to "neutron flow" and consequent neck formation between the projectile and target. The results of a new experiment using the radioactive nuclear beam facility at the University of Notre Dame to measure fast ⍺-particle emission from 6He …


Motion-Based Video Representation For Scene Change Detection, Chong-Wah Ngo, Ting-Chuen Pong, Hong-Jiang Zhang, Roland T. Chin Sep 2000

Motion-Based Video Representation For Scene Change Detection, Chong-Wah Ngo, Ting-Chuen Pong, Hong-Jiang Zhang, Roland T. Chin

Research Collection School Of Computing and Information Systems

We present a new ly developed scheme for automatical ly partitioning videos into scenes. A scene is general ly referred to as a group of shots taken place in the same site. In this paper, we first propose a motion annotation algorithm based on the analysis of spatiotemporal image volumes. The algorithm characterizes the motions within shots by extracting and analyzing the motion trajectories encoded in the temporal slices of image volumes. A motion-based keyframe computing and selection strategy is thus proposed to compactly represent the content of shots. With these techniques, we further present a scene change detection algorithm …


Knowledge Discovery In Biological Databases : A Neural Network Approach, Qicheng Ma Aug 2000

Knowledge Discovery In Biological Databases : A Neural Network Approach, Qicheng Ma

Dissertations

Knowledge discovery, in databases, also known as data mining, is aimed to find significant information from a set of data. The knowledge to be mined from the dataset may refer to patterns, association rules, classification and clustering rules, and so forth. In this dissertation, we present a neural network approach to finding knowledge in biological databases. Specifically, we propose new methods to process biological sequences in two case studies: the classification of protein sequences and the prediction of E. Coli promoters in DNA sequences. Our proposed methods, based oil neural network architectures combine techniques ranging from Bayesian inference, coding theory, …


Deactivation And Enhancement Effects Of Sulfur On Supported Platinum Oxidation Catalysts, Mark Ladolcetta Aug 2000

Deactivation And Enhancement Effects Of Sulfur On Supported Platinum Oxidation Catalysts, Mark Ladolcetta

Dissertations

The effects of sulfur poisoning on the oxidation activity of 1.5 % Pt/γ-Al2O3, Pt/TiO2, Pt/ZrO2, and Pt/SiO2, were investigated in this study. Each catalyst was poisoned with an H2S/air or SO2/air mixture at 400°C for 24 hours and a sulfur concentration of 200 ppm. The complete oxidation of mixtures of I % CO, methane, ethane, ethene, ethyne, propane, propene, and n-butane in air were measured over fresh and sulfurpoisoned catalysts.

Non-methane alkane oxidation activity was enhanced significantly after sulfur poisoning on all four catalysts. The temperatures …


On Some Self-Organizing Models And Their Applications., Amitava Dutta Dr. Aug 2000

On Some Self-Organizing Models And Their Applications., Amitava Dutta Dr.

Doctoral Theses

Abstract: Self-organizing neural network models constitute the main theme of this thesis. Some well-known self-organizing models are surveyed and their properties are discussed. The application areas on which the thesis focuses are briefly described.This thesis deals with Artificial Neural Network models, in particular, Self- organizing (unsupervisnd) models. We develop here a few self-organizing neural net- work models to solve certain problems which are well studied in the areas of Image Processing and Computationel Geometry and have wide applications in shape eztrac- tion and optimization.1.1 Artificial neural networkThe study of Biological Neural Networks originally comes under biological sciences. They deal with …


Electrochemical Investigations Of Semiconductor Silicon Wafers, Xuan Cheng, Chang-Jian Lin Aug 2000

Electrochemical Investigations Of Semiconductor Silicon Wafers, Xuan Cheng, Chang-Jian Lin

Journal of Electrochemistry

Electrochemical characteristics of semiconductor silicon wafers were investigated in dilute hydrofluoric acid solutions using DC polarization and AC impedance techniques under both illuminated and dark conditions. Both techniques were extremely sensitive to the trace amount (10-9 wt% level) of copper presented in solutions, but only sensitive to the 10-6 wt% level of non ionic surfactant OHS contained in solutions. The results revealed that the electrochemical reactions took place favorably and became predominated at silicon/solution interface under illuminated condition.


The Effect Of Cerium On The Anodic Behavior Of Pb-Ca-Sn Alloy In Sulfuric Acid Solution, Hou-Tian Liu, Jiong Yang, Hai-He Liang, Ji-Hua Zhuang, Wei-Fang Zhou Aug 2000

The Effect Of Cerium On The Anodic Behavior Of Pb-Ca-Sn Alloy In Sulfuric Acid Solution, Hou-Tian Liu, Jiong Yang, Hai-He Liang, Ji-Hua Zhuang, Wei-Fang Zhou

Journal of Electrochemistry

The cyclic voltammograms for Pb - 0.5 at% Ca - 1.5 at% Sn and Pb - 0.5 at% Ca - 1.5 at% Sn containing a certain amount of cerium in 4.5 mol·dm-3 H2SO4 at 20℃ were measured between 0.6 V and 1.4 V(vs. Hg/Hg2SO4). The growth rate of the anodic Pb(Ⅱ) films formed on the mentioned alloy electrodes at 0.9 V in the same sulfuric acid medium was investigated using the Linear Sweep Voltammetry. The variation with electrode potential of the real part of the impedence (Z’) for the anodic Pb(Ⅱ) films …


The Electro-Catalytic Oxidation Of Hcooh On Electrodeposited Pd Electrode, Quan Zhou, Cun-Zhong Zhang, Xiao-Lin Lu, Zhong-Da Wu Aug 2000

The Electro-Catalytic Oxidation Of Hcooh On Electrodeposited Pd Electrode, Quan Zhou, Cun-Zhong Zhang, Xiao-Lin Lu, Zhong-Da Wu

Journal of Electrochemistry

The coherent electroplates were prepared by electro depositing Pd on supporting materials glassy carbon. The surface morphology of the electrodes was examined by SEM. The electro oxidation of HCOOH in HClO4 solution was investigated by using cyclic voltammetry. The results show that the deposited conditions in the preparation of electrodes by electro depositing Pd affect the electrodes electro catalytic activity to the oxidation of HCOOH. The platinized Pd electrode on GC substrates using large current density is of higher catalytic activity to the oxidation of HCOOH than Pd electrode. The electro catalytic activity of PdO formed on the Pd …


Electrochemical Characteristics Of Sb Irreversibly Adsorbed On Pt(100), Pt(110), Pt(111) And Pt(320) Electrodes, Yi-Yun Yang, Zhi-You Zhou, Qi-Hui Wu, Shi-Gang Sun Aug 2000

Electrochemical Characteristics Of Sb Irreversibly Adsorbed On Pt(100), Pt(110), Pt(111) And Pt(320) Electrodes, Yi-Yun Yang, Zhi-You Zhou, Qi-Hui Wu, Shi-Gang Sun

Journal of Electrochemistry

The electrochemical behaviors of irreversibly adsorbed antimony on Pt(100), Pt(110), Pt(111) and Pt(320) were studied by using cyclic voltammetry. The results revealeds that the Sb adatoms are stable on Pt(100), Pt(110), Pt(111) and on Pt(320) when electrode potentials are below 0.45 V(SCE) and 0.40 V, respectively. It was demonstrated that various coverages of Sb ad can be conveniently obtained by controlling the number of potential cycling and varying the upper limit of potential scan. The electrochemical behaviors of irreversibly adsorbed antimony varied with the surface atomic arrangement of Pt single crystal electrodes. Based on quantitative results of the relationship between …


A Study On Stochastic Resonance For The Process Of Active-Passive Transition Of Iron In Sulfuric Acid, Hong-Bo Ding, Bao-Yun Xia, Chun-Sheng Yin, Zhong-Xiao Pan, Renato Seeber Aug 2000

A Study On Stochastic Resonance For The Process Of Active-Passive Transition Of Iron In Sulfuric Acid, Hong-Bo Ding, Bao-Yun Xia, Chun-Sheng Yin, Zhong-Xiao Pan, Renato Seeber

Journal of Electrochemistry

The bistable characteristics of the process of active passive transition of iron in sulfuric acid was described and the stochastic resonance phenomenon in the process was simulated.


Mechanisimic Study Of Fes Electrode Process, Cong-Sheng Guan, Shu-Zhen Duan Aug 2000

Mechanisimic Study Of Fes Electrode Process, Cong-Sheng Guan, Shu-Zhen Duan

Journal of Electrochemistry

The mechanism of FeS electrode process has been investigated by using linear cyclic voltammetry. The electrode porcess of FeS is accompanied with the formation and dissolution of insoluble FeS and controlled by ohmic resistance. The peak currents and potentials on the cyclic voltammograms are dependent lineally on the square root of the scan rates. According to this, an ohmic resistance controlling model of FeS electrode has been put forward, and the relative functions between peak currents or potentials and scan rates have been deduced. The theoretical deduction is corresponding to the results of the experiments.


Electrochemical Evaluation On The Porosity Of Electroless Ni-P Alloy Coatings, Hong-Ying Yu, Dong-Bai Sun, Jing-Bing Huang, De-Jun Yang Aug 2000

Electrochemical Evaluation On The Porosity Of Electroless Ni-P Alloy Coatings, Hong-Ying Yu, Dong-Bai Sun, Jing-Bing Huang, De-Jun Yang

Journal of Electrochemistry

By investigating the polarization curves of pure Ni-P alloy, Ni-P alloy coation and carbon steel in nitric acids with different concentrations, the sutable concentration of nitric acid for the evaluation of the porosity of Ni-P alloy coatings has been determined and the coatings with different thickness have been evaluated. The results indicated that the nitric acid with 10 wt% concentration is the most suitable solution for the porosity of the coating by using electrochemical method. The polarization curve of Ni-P alloy coating in 10% nitric acid can accurately reveal the porosity. With the decrease of the porosity of the coating, …


Three-Dimensional Microfabrication On Gaas Using A Regular Patterns Mold, Hai-Gou Huang, Jian-Jun Sun, Xiong-Ying Ye, Li-Min Jiang, Jin Luo, Ze-Sheng Lu, Shen Dong, Zhong-Qun Tian, Zhao-Ying Zhou, Zhao-Wu Tian Aug 2000

Three-Dimensional Microfabrication On Gaas Using A Regular Patterns Mold, Hai-Gou Huang, Jian-Jun Sun, Xiong-Ying Ye, Li-Min Jiang, Jin Luo, Ze-Sheng Lu, Shen Dong, Zhong-Qun Tian, Zhao-Ying Zhou, Zhao-Wu Tian

Journal of Electrochemistry

Electrochemical etching of single crystal GaAs (111) was performed with a regular mold which resembles the micro-gear patterns. The etched patterns on GaAs was very consistent with the negative copies of the mold when the confined etchant layer technique (CELT) was used. However when the scavenger chemical of H3AsO3 was not added in the etching solution, the regular micro-gear patterns of the mold could not be obtained. In addition, the procedure of fabricating a electrochemical mold is introduced and the characteristics of the mold are briefly discussed.


Cathodic Indirect Oxidation Of Organic Compounds(Ⅱ)——Cathodic Indirect Epoxidation Of Olefine, Xue-Ying Zhang, Bao-Qiu Cui, Deng-Ping Gu, Wei Li Aug 2000

Cathodic Indirect Oxidation Of Organic Compounds(Ⅱ)——Cathodic Indirect Epoxidation Of Olefine, Xue-Ying Zhang, Bao-Qiu Cui, Deng-Ping Gu, Wei Li

Journal of Electrochemistry

We described a novel cathodic indirect epoxidation system in which O2 was first cathodically reduced to H2O2. Then VO(acac)2 was oxidized by H2O2 homogeneously to VO(acac)2OOH which was used to epoxidize some olefine such as maleic, fumaric and crotonic acids. Many affecting factors on the current efficiency were optimized. The research will contribute to the developments of organic electrosynthesis.


The Study On Lithiated Titanium Composite Oxides As Negative Electrode For Lithium-Ion Battery, Xiao-Yan Yang, Shou-Nan Hua, Shu-Yong Zhang Aug 2000

The Study On Lithiated Titanium Composite Oxides As Negative Electrode For Lithium-Ion Battery, Xiao-Yan Yang, Shou-Nan Hua, Shu-Yong Zhang

Journal of Electrochemistry

Lithiated titanium composite oxides Li4Ti5O12 were prepared from Li2CO3 and TiO2. The XRD results of this composite oxides indicated that the compound had a spinel structure. The electrochemical behavior of lithiated titanium composite oxides was examined. The results showed that this material had an excellent cyclic capability and reversibility for lithium insertion, and had high specific capacity: the initial discharge capacity was 300 mAh·g-1 , and the reversible capacity was 100 mAh·g-1 . The discharge plateau (about 1.5 V) and the charge plateau (about 1.6 V) were very …


Studies Of The LialYNi1-YO2 As Cathode Materials For Rechargeable Lithium Ion Batteries, Xiao-Gan Li, Wei-Hua Qiu, Chuan-Gang Lin, Qing-Guo Liu Aug 2000

Studies Of The LialYNi1-YO2 As Cathode Materials For Rechargeable Lithium Ion Batteries, Xiao-Gan Li, Wei-Hua Qiu, Chuan-Gang Lin, Qing-Guo Liu

Journal of Electrochemistry

In this paper, we have synthesized series of single-phase LiAlyNi1-yO2 (differentive in value-y) by solid reaction. Through examining their electrothemical properties, found that, under a proper sintering condition, LixAl0.25Ni0.75O2 solution for cathode materials of rechargeable lithium ion batteries showed more pleasing properties in overcharge-resist and cycling life (vs LiNiO2). When x>1, the capacity can be kept 125mAh/g after 30 cycles under higher charged/discharged voltages ranging from 3.0 V to 4.8 V, whereas that of pure LiNiO2 has only 61 nAh/g after 25 cycles. The …


Synthesis Of Li1+XMn2O4 Cathode Material For Lithium-Ion Batteries With Solution Method, Pei-Song Liu, Sing-Quarn Liu, Qing Li, Zhao-Yong Chen, Bai-Lan Zhang, Zuo-Long Yu Aug 2000

Synthesis Of Li1+XMn2O4 Cathode Material For Lithium-Ion Batteries With Solution Method, Pei-Song Liu, Sing-Quarn Liu, Qing Li, Zhao-Yong Chen, Bai-Lan Zhang, Zuo-Long Yu

Journal of Electrochemistry

The cathode materials Li1+xMn2O4 were prepared with citric acid complexing and solution impregnating methods. Structure characterization and specific surface area test were performed by means of XRD, BET methods, the influences of calcination temperature, Li/Mn molar ratio and raw materials on the structure and electrochemical capacity of samples have beem examined. The results showed that the Li/Mn molar ratio and calcimation temperature were the key factors affecting the electrochemical capacity of cathode materias. The optimum conditions for synthesis of  Li1+xMn2O4 cathode material were 0≤x≤0.05 and calcined at 750°C. The initial …


The Effect Of Anode Thickness In Sofcs With Anode Supported Ysz Film, Yi-Huang Zhang, Yi Jiang, Zi-Gui Lu, Yong-Lai Dong, Jing-Wang Yan Aug 2000

The Effect Of Anode Thickness In Sofcs With Anode Supported Ysz Film, Yi-Huang Zhang, Yi Jiang, Zi-Gui Lu, Yong-Lai Dong, Jing-Wang Yan

Journal of Electrochemistry

Solid oxide fuel cells with supported yttria stabilized zirconia electrolyte films on anode substrates of various thickness have been fabricated. The electrochemical performances of the SOFCs have been examined. The results showed that the cell performance was limited by the anodic overpotential, which is caused mainly by a concentration polarization when the anode substrate is thick. The anodic overpotential was reduced obviously as the thickness of anode substrate was decreased. As a result, the performance of the SOFC cell was improved. With a 0.5 mm anode substrate, a SOFC cell produced a power density about 0.19 W/cm2 at 800 …


A New Method For The Preparation Of The Electrodes With Very Low Platinum Loading Used In Proton Exchange Membrane Fuel Cell, Zhi-Gang Shao, Bao-Lian Yi, Ming Han, Ya-Guang Qiao, Hao Liu, Jing-Rong Yu Aug 2000

A New Method For The Preparation Of The Electrodes With Very Low Platinum Loading Used In Proton Exchange Membrane Fuel Cell, Zhi-Gang Shao, Bao-Lian Yi, Ming Han, Ya-Guang Qiao, Hao Liu, Jing-Rong Yu

Journal of Electrochemistry

Research and development on low platinum loading electrode is very important in reducing the cost of proton exchange membrane fuel cell(PEMFC) stack. This paper has put forward a new method to prepare the electrode of PEMFC. The pore forming substances were used in this methd. The low platinum loading electrodes (0.02 mgPt⋅cm-2) have already been prepared with the method. Compared with the traditional method, the new method is simple, cheep, and easy to scale up. The superior composition of the electrodes is catalyst: pore forming substance: Nafion= 3:3:1. The performance of a single cell using this …


The Electrochemical Polymerization Of Erythrosin And The Fluorescence Spectra Of Polyerythrosin, Hong-Ping Zhu, Shao-Lin Mu Aug 2000

The Electrochemical Polymerization Of Erythrosin And The Fluorescence Spectra Of Polyerythrosin, Hong-Ping Zhu, Shao-Lin Mu

Journal of Electrochemistry

The solution used for the electrolysis consisted of 0.03 mol·dm-3 erythrosin, 0.05 mol·dm-3 sodium tetraborate and 0.5 mol·dm-3 KCl with pH 8.50. Polyerythrosin film with red color has been electrochemically synthesized using repeated potential cycling between -0.20 and 1.10 V (vs.SCE). The film growth and the electrochemical property of polyerythrosin are affected by electrolytic conditions. Two main absorption peaks of polyerythrosin at 326 nm and 370 nm appear in the UV-visible spectrum, which are different from that of the monomer. Polyerythrosin in dimethyl sulfoxide or dimethylformamide has a strong fluorescence intensity and the fluorescence intensity of polyerythrosin …


Pulse Potential Modulated Electrochemical Gas Sensors, Zhong-Bai Zhou, Liang-Dong Feng, Wen-Jun Liu Aug 2000

Pulse Potential Modulated Electrochemical Gas Sensors, Zhong-Bai Zhou, Liang-Dong Feng, Wen-Jun Liu

Journal of Electrochemistry

The current popular electrochemical gas sensors are mostly stable with regard to their operating states. As a result, the further improvement of sensor charcateristics is restricted by such a "steady state". Based on the transient electrochemistry principle, a kind of all new transient electrochemical multi component gas sensors— "pulse potential modulated electrochemical gas sensors" was established by combining computer controlled fast modulated potential technique with microelectrode method.This novel approach provided a real time and dynamic sensor technique integrated with acquisition, treatment and display of signals for rapid simultaneous detecion of multicomponent gases, as illustrated by the case of monitoring of …


Corrosion Behavior Of Reinforcing Steel In Concrete, Rong-Gui Du, Rong-Gang Hu, Zu-De Feng, Jiang-Guang Tan, Chang-Jian Lin Aug 2000

Corrosion Behavior Of Reinforcing Steel In Concrete, Rong-Gui Du, Rong-Gang Hu, Zu-De Feng, Jiang-Guang Tan, Chang-Jian Lin

Journal of Electrochemistry

The corrosion behavior of reinforcing steel in concrete in chloride free and chloride contaminated simulated concrete solutions was studied by electrochemical technique. The results showed that the reinforcing steel exhitibted different corrosion characteristics in the different solutons. In general, the steel in concrete was protected in the test solutions with no salt or the lower concentration of NaCl. When the concentration of NaCl is larger than 70%, however, the corrosion behavior of the steel varied considerably, and the corrosion rate increased as pH fell and the concentration of Cl- increased.


A Study On The Cylindrical Zinc-Air Battery, Sheng-Sian Li, Gui-Mao Zhou, Xin-Ping Ai, Han-Xi Yang Aug 2000

A Study On The Cylindrical Zinc-Air Battery, Sheng-Sian Li, Gui-Mao Zhou, Xin-Ping Ai, Han-Xi Yang

Journal of Electrochemistry

The zinc air battery has advantages of high specific energies and low cost, therefore attracts much interests. However, its application is limited only in prismatic and button type.This paper reported a novel design of cylindrical zinc air batteries and the performances of the batteries tested at various conditions. The results showed that when discharged at the current of 40 mA at 20 °C, the capacity of AA size and AAA size batteries reached 4000mAh and 1400mAh respectively, corresponding to the energy densities 280 Wh/kg and 200 Wh/kg. The effects of the discharge current, temperature and humidity on the performances of …


The Lineal Polarization Method For Corrosion Rate Measurement Of Reinforcing Bar Of Concrete In Situ, Ai-Ling Du, Wen-Tao Hou, He-Ming Zhang, Jian-Qun Luo Aug 2000

The Lineal Polarization Method For Corrosion Rate Measurement Of Reinforcing Bar Of Concrete In Situ, Ai-Ling Du, Wen-Tao Hou, He-Ming Zhang, Jian-Qun Luo

Journal of Electrochemistry

A linear polarization method was applied to measure corrosion rate of reinforcing bar of concrete in situ. Generally in the experiment, the area and shape of the reinforcing bar as a working electrode can be changed and adjusted according to our needs. But polarization area cannot be defined when reinforcing bar is polarized in situ, so that a real Rp can't be obtained. Thus the purpose of present work is to improve the measurement system. We used the double-ring auxiliary electrodes made by ourselves. The size of the double-ring auxiliary electrodes was adjusted repeatedly until the real polarization area …