Electrochemical behavior of mesh and plate oxide coated anodes during zinc electrowinning

The catalytic performance of two oxides coated anodes （OCSs） meshes and one OCA plate was investigated in a zinc electrowinning electrolyte at 38 ℃. Their electrochemical behaviors were compared with that of a conventional Pb-0.7%Ag alloy anode. Electrochemical measurements such as cyclic voltammetric, galvanostatic, potentiodynamic, open-circuit potential （OCP） and in situ electrochemical noise measurements were considered. After 2 h of OCP test, the linear polarization shows that the corrosion current density of the Ti/（IrO2-Ta2O5） mesh electrode is the lowest （3.37μA/cm^2） among the three OCAs and shows excellent performance. Additionally, after 24 h of galvanostatic polarization at 50 mA/cm^2and 38 ℃, the Ti/MnO2mesh anode has the highest potential （1.799 V）, followed by the Ti/（IrO2-Ta2O5） plate （1.775 V） and Ti/（IrO2-Ta2O5） mesh （1.705 V） anodes. After 24 h of galvanostatic polarization followed by 16 h of decay, the linear polarization method confirms the sequence obtained after 2 h of OCP test, and the Ti/（IrO2-Ta2O5） mesh attains the lowest corrosion current density. The Ti/（IrO2-Ta2O5） mesh anode also shows better performance after 24 h of galvanostatic polarization with the overpotential lower than that of the conventional Pb-Ag anode by about 245 mV.

NETLAB-An Internet based laboratory for electrical engineering education

This article describes an Internet based laboratory (NETLAB) developed at Zhejiang University for electrical engi- neering education. A key feature of the project is the use of real experimental systems rather than simulation or virtual reality. NELTAB provides remote access to a wide variety of experiments, including not only basic electrical and electronic experiments but also many innovative control experiments. Students can effectively use the laboratory at any time and from anywhere. NETLAB has been in operation since July 2003.

Adaptive Spectr um Decision Method for Heterogeneous Cognitive Radio Networks

To improve spectrum utilization and minimize interference to Primary User (PU), an adaptive spectrum decision method is proposed for Secondary User (SU), while taking traffic load balancing and spectrum heterogeneity into consideration. Long-term statistics and current sensing results are integrated into the proposed decision method of spectrum access. Two decision methods, namely probability based and sensing based, are presented, compared and followed by performance analysis in terms of delay. For probability based spectrum decision, Short-Time-Job-First (STJF) priority queuing discipline is employed to minimize average residual time and theoretical conclusion is derived in a novel way. For sensing based decision we treat the interrupted service of SU as newly incoming and re-decision process is initialized to find available spectrum in a First-Available-First-Access (FAFA) fashion. Effect of sensing error in PHY layer is also analyzed in terms of extended average residual time. Simulation results show that, for relatively low arriving rate of SU traffic, the proposed spectrum decision method yields at least a delay reduction of 39.5% compared with non-adaptive method. The proposed spectrum decision can significantly improve delay performance even facing sensing errors, which cause performance degeneration to both PU and SU.

On the Backlog and Delay Distributions of Primary and Secondary Users in a Cognitive Radio Network

In a cognitive radio network, the secondary users can use the spectrum holes when the primary users do not utilize the spectrum, but they must vacant the spectrum when the primary users need to transmit data on the spectrum. In other words, the primary users have higher priority over the secondary users. In this paper, backlog and delay distribution bounds for both primary users and secondary users are obtained. The analysis is based on stochastic network calculus, for which, stochastic service curves are t-n-st derived for both primary users and secondary users, and the network calculus independent case analysis approach is used to find the distribution bounds. Numerical results and simulation results are also presented and discussed.

Application of New Type BP Neural Networks for Magnetic Measurement

Magnetic measurement is a typical inverse problem in Biomedical field. In this kind of problem we always need to locate the positions and moments of one or more magnetic dipoles. Although using the traditional methods to solve this kind of inverse problem has all kinds of shortcomings, BPNN (Back Propagation Neural Networks) method can be used to solve this typical inverse problem fast enough for real time measurement. In the traditional BPNN method, gradient descent search method is performed for error propagation. In this paper the authors propose a new algorithm that Newton method is performed for error propagation. For the cost function is highly nonconvex in the magnetic measurement problem, the new kind of BPNN can get convergent results quickly and precisely. A simulation result for this method is also presented.

Investigation of the Relevance Between Electronic Courseware Implementation and Students’ Learning Styles

Currently many methods of implementation are available if we want the com＇seware to be used in e-learning interactivly with media rich. This paper focuses the attention to the relevance between various implementations in presentation adopted in the courseware and students＇ learning styles, in order to consider what kind of implemenation or description is preferable to what kind of students or order to support their leaming. We carded out the canonical correlation analysis for this purpose and investigated this relevance on the basis of the experiments. Main results of the experiment are given with detailed disoussion.

Identification and novel adaptive fuzzy control of nonlinear system for PEMFC stack

The operating temperature of a proton exchange membrane fuel cell stack is a very important control parameter. It should be controlled within a specific range, however, most of existing PEMFC mathematical models are too complicated to be effectively applied to on-line control. In this paper, input-output data and operating experiences will be used to establish PEMFC stack model and operating temperature control system. An adaptive learning algorithm and a nearest-neighbor clustering algorithm are applied to regulate the parameters and fuzzy rules so that the model and the control system are able to obtain higher accuracy. In the end, the simulation and the experimental results are presented and compared with traditional PID and fuzzy control algorithms.

Models for Teaching Culture in Computer-Assisted Language Learning

CALL （computer-assisted language learning） has tremendously transformed the teaching of language, with its wide application in many aspects of language teaching. However, how to integrate CALL into the teaching of culture is still rarely discussed. The purpose of the paper is to explore feasible models for teaching culture in CALL and their effects on students＇ acquisition process. Based on two fundamental pedagogical approaches （participatory pedagogy and multiliteracies pedagogy） for teaching culture, this paper proposes three pedagogical models （problem-posing model, web-quest model, and computer-supported collaborative learning model） for teaching culture in CALL. In the end, this paper illustrates a combination of the three models in real CALL setting by a cultural teaching case. A questionnaire survey and interviews are conducted to reflect on students＇ feedback, which gives an insight into possible adjustments in teaching models and the paper also proposes future possibilities in applying these models into teaching culture

Finding Consistency in Rousseau

Several of Rousseau＇s critics begin with the presupposition that his writings are inconsistent or incoherent ann proceed to locate the ＂essence＂ of his philosophy in some of his writings while excluding others. Ernst Cassirer is among the few philosophers who have attempted to defend Rousseau＇s claim to consistency. Despite its broad influence, Cassirer＇s interpretation has remained largely unchallenged. The aim of this paper is twofold. Firstly, it aims to show that Cassirer＇s interpretation undermines （1） the important role Rousseau assigns to pity in both the state of nature and civil society and （2） the significant role the general will plays in his political theory. Secondly, it proposes an alternative interpretation that succeeds in uniting Rousseau＇s opus.

Fashion Films and Net-aesthetics

Fashion Film is the last communication tool in fashion market, that was born for the Web about 20 years ago, but in these last 10 years it has increased its diffusion and its expressive potentiality definitely and we think that it is designed to influence the communication in other markets. Nowadays Fashion Films are reinforcing the power of fashion images, building up new brand experiences for net-consumers： they are painting new worlds for fashion brands thanks to the old cinematographic language mixed to recent Internet logics. Starting from this observation, our main question was： Can we talk about a new fashion net-aesthetics for these new fashion tales？ Using a semiotics approach, this study investigates how Fashion, Cinema and the Net come together, producing new aesthetics, with new languages and new imaginary in fashion. The result can be really visionary.

Longitudinal Magnetoresistance and ＂Chirar＇ Coupling in Silver Chalcogenides

A complex longitudinal magnetoresistance （MR//） effect in the non-stoichiometric silver chaJcogenides （include the silver selenide and telluride） has been found, however the mechanism for the MR// effect is not clear now. In this work, a new random resistor network for MR// effect is proposed based on the experimental observation. The network is constructed from six-terminal resistor units and the mobility of carries within the network has a Gaussian distribution. Considering the non-zero transverse-longitudinal coupling in materials, the resistance matrix of the six- terminal resistor unit is modified. It is found that the material has the ＂chiral＂ transverse-longitudinal couplings, which is suggested a main reason for the complex MR//effect. The model predictions are compared with the experimental results. A three dimension （3D） visualization of current flow within the network demonstrates the ＂current jets＂ phenomenon in the thickness of materials dearly.

Transmission Mechanism Based on Burst Filling in Hybrid Optical Burst/Circuit Switching Networks

Hybrid optical switching networks make full use of the advantages of Optical Circuit Switching(OCS)and Optical Burst Switching(OBS).In parallel hybrid optical switching networks,edge nodes choose a switching mode for traffic and no longer change.The inflexible decision making of the traffic transfer mode leads to low resource utilization when the arrival rate of the OCS traffic is lower than the capacity of the light path.In this paper,a new transmission scheme is proposed to improve resource utilization for hybrid optical switching networks.When the traffic arrival rate of the light path is lower than the transmission rate of the light path,the OCS traffic flow is reshaped at the edge nodes to generate a series of voids.Then,several message packets are sent along the light path to inform the core nodes of the voids of the light paths that represent the unused bandwidth resources.To improve the resource utilization,the voids can be filled with data bursts by core nodes.The simulation results show that the new scheme can effectively reduce the burst loss rate and improve the link utilization of the hybrid optical switching network on the premise of a providing service quality guarantee for OCS traffic.

The Design and Implementation of the Network Interactive Virtual Experiment Platform for Electronic Information Courses

Experimental teaching plays a crucial role in the trainings of students＇ abilities to analyze and solve problems. Therefore, it is very necessary to continuously carry out experiment teaching reform, improve experiment teaching methods and means, and comprehensively open laboratories so as to provide students with more opportunities of doing experiments. To improve the teaching effect of electronic information experimental courses, a network interactive virtual experimental platform is developed. This platform allows students to finish the construction of all kinds of circuit structures and test virtual instruments in a simulation environment, upload experimental data and also interactively communicate with teachers through the lnternet. The platform can be applied to the teaching activities of related electronic information experimental courses, and also can be used as an aid teaching method for theory teachers. Therefore, it possesses a very good interactivity, and makes up the disadvantages of the experimental teaching in hardware environment, so that a feasible solution is provided for the opening of laboratories.

Electronic Database about Children with Special Needs ~t Primary School

In Slovenia, children with special needs have been included to primary schools since 1998. Since then, teachers have had a lot of work to be done. Every year they have to prepare an individualized programme for each child with special needs. They have to set goals that each child with special needs has to achieve at a particular subject. Pupils have different teachers every year and to make their work easier, the author is considering making a website database with basic information about them. This database would state the goals that the pupil achieved in the past year, which strategy of teaching proved to be the best for him or her and what the areas he or she needs help with are. Teachers would be collecting this data during the primary education, after the final evaluation this database would also be made available to the secondary school of the pupil in concern. This database should be located on the website of Ministry of Education, Science, Culture and Sports. It would be available to primary schools, but protected by a password which would grant the school access to the data of their students only. In secondary schools, teachers could also access to the information, so they would not have to be discovering appropriate teaching strategies that worked for a pupil in the past all over again. This would enable better conditions and a successful education for pupils with special needs.

Highly stretchable pseudocapacitors based on buckled reticulate hybrid electrodes

In order to develop an excellent pseudocapacitor with both high specific capacitance and outstanding stretchability to match with other devices applicable in future wearable and bio-implantable systems, we focus our studies on three vital aspects： Stretchability of hybrid film electrodes, the interface between different components, and the integrated performance in stretchability and electrochemistry of supercapacitors based on single-walled carbon nanotube/ polyaniline （SWCNT/PANI） composite films on pre-elongated elastomers. Owing to the moderate porosity, the buckled hybrid film avoids the cracking which occurs in conventional stretchable hybrid electrodes, and both a high specific capacitance of 435 F.g-1 and a high strain tolerance of 140% have been achieved. The good SWCNT/PANI interfacial coupling and the reinforced solid electrolyte penetration structure enable the integrated pseudocapacitors to have stretch- resistant interfaces between different units and maintain a high performance under a stretching of 120% elongation, even after 1,000 cyclic elongations.

Flexible three-dimensional-networked iron vanadate nanosheet arrays/carbon cloths as high-performance cathodes for magnesium ion batteries

Owing to their safety and low cost,magnesium ion batteries(MIBs)have attracted much attention in recent years.However,the sluggish diffusion dynamics of magnesium ions hampers the search for appropriate cathode materials with excellent electrochemical performance.Herein,we design and synthesize a novel flexible three-dimensional-networked composite of iron vanadate nanosheet arrays/carbon cloths(3 D FeVO/CC)as a binder-free cathode for MIBs.Relative to bare FeVO nanosheets,the 3 D binder-free electrode with designed architecture enables a full range of electrochemical potential,including a high specific capacity of270 mA h g^(-1) and an increased life span(over 5000 cycles).Such achievable high-density energy originates from the synergistic optimization of electron and ion kinetics,while the durability benefits from the robust structure that prevents degradation in cycling.The single-phase reaction mechanism of FeVO in the magnesium ion storage process is also explored by in-situ X-ray diffraction and Raman technologies.Moreover,a flexible MIB pouch cell(3 D FeVO/CCIMgNaTi_(3)O_(7)) is assembled and exhibits practical application potential.This work verifies that 3 D FeVO/CC is a potential candidate cathode material that can satisfy the requirements of highperformance MIBs.It also opens a new avenue to improve the electrochemical performance of cathode materials for MIBs.

Steric paper based ratio-type electrochemical biosensor with hollow-channel for sensitive detection of Zn2+

The construction of flexible platform possessing the functions of immobilizing, separating, rinsing, and high-throughput analysis plays a significant role in biological and clinical research. Herein, hollow- channel technique was integrated with lab-on-paper for the simultaneous determination of two different concentrations of Zn2＋ based on the origami principle, in which microfiuidic channels were first patterned on a cellulose paper using commercial solid-state wax printer. Hollow-channels were created by laser cutting method as the role of both injecting ending and reaction tank. After screen printing three elec- trodes system, the resulting planar paper sheets were then folded into steric structures and functional- ized by in-situ synthesized reduced graphene oxide. As a proof-of-concept, such lab-on-paper device was employed in the ratiometric electrochemical monitoring of zinc ion from the environment and HepG2 cells extract, by combining with co-catalysis of porous metal-organic frameworks and hemin/ G-quadruplex toward H202 in the linear range of 0.1-7,000 nmol/L. The results indicated that integrating hollow-channel with steric lab-on-paper offered a new methodological approach for the development of metal ions monitoring research. It is believed that it could be useful for various point-of-care related research fields, such as, on-site environmental monitoring, food safety, and disease diagnosis.

Improving the electrochemical performance of Fe3O4 nanoparticles via a double protection strategy through carbon nanotube decoration and graphene networks

Iron oxide is a promising anode material for lithium ion batteries, but it usually exhibits poor electrochemical property because of its poor conductivity and large volume variation during the lithium uptake and release processes. In this work, a double protection strategy for improving electrochemical performance of Fe3O4 nanoparticles through the use of decoration with multi-walled carbon nanotubes and reduced graphene oxides networks has been developed. The resulting MWCNTs-Fe3O4-rGO nanocomposites exhibited excellent cycling performance and rate capability in comparison with MWCNTs-Fe3O4, MWCNTs-Fe3O4 physically mixed with rGO, and Fe3O4-rGO. A reversible capacity of -680 mA·h·g^-1 can be maintained after 100 cycles under a current density of 200 mA.g^-1.

Electrocatalytic evolution of oxygen on NiCu particles modifying conductive alumina/nano-carbon network composite electrode

In this paper, a novel electrically conductive alumina/nano-carbon network (NCN) composite material was used as an electro- catalyst carrier. A NiCu/Al2O3 /NCN composite electrode was prepared by electrodepositing NiCu particles onto the surface of the conductive alumina/NCN composite. Morphology, composition, crystalline structure and electrochemical properties of the NiCu/Al2O3 /NCN composite electrode were investigated. The results showed that NiCu particles can be deposited onto the surface of the alumina/NCN composite by a coelectrodeposition method. NiCu particles in the form of solid solution with face-centered cubic (fcc) structure were relatively uniformly distributed over the carbon layer of the conductive ceramic between alumina grains. As-resulted NiCu/Al2O3 /NCN composite electrode had a remarkably enhanced electrochemical activity and high stabilization for oxygen evolution reaction, which indicated its potential application with enhanced performance to oxygen evolution reaction (OER). Moreover, based on the electrochemical measurement, the mechanism of the OER on the NiCu/Al2O3 /NCN composite electrode was discussed.