LOW POTENTIAL ELECTROPOLYMERIZATION OF ANISOTROPIC CONDUCTIVE POLYTHIOPHENE FILMS AND FABRICATION OF ELECTRICAL DEVICES

The Complexation of thiophene with a Lewis acid with moderate acidity as a solvent, such as BF3-ethyl ether (BFEE) remarkedly lowered the electrochemical polymerization potential. The positively charged metal surface of electrode in the process of electrochemical deposition enhanced the coordination interaction between pi-electrons of thiophene unit and the metal, which makes thiophene rings lie parallel to the surface of electrode, resulting in a highly ordered polymeric structure. Because of the large intra-chain transfer integrals, the transport of charge is believed to be principally along the conjugated chains, which is much greater than the inter-chain hopping. The specific electrical resistance across the polythiophene film thickness is more than 10(4) times than that along the surface plane of the film. In this paper we review the recent development of polymerization technique by low potential electrochemical method performed in our lab and several electrical devices in which the compact polythiophene films, such as anionic and cationic sieves, and laminate film junction of undoped polythiophene derivatives were used.

Vision implants:An electrical device will bring light to the blind

Cochlear implant has been successfully applied in clinic. Recent research indicates vision implants may be the potential way to restore sight for the blind. Here, principle and common structure of vision implants are introduced. Main vision approaches of retinal, optic nerve, and cortical prosthesis are reviewed. In our progress, electrical response at visual cortex is recorded, when penetrating electrodes stimulate rabbit optic nerve, vision implants based on optic nerve stimulator chip （ONSC） and Chipcon radio frequency （RF） chip are under developing. Despite several obstacles to overcome, promising results in animal and human experiments give scientists confidence that artificial vision implants will bring light to the blind in the near future.

Electrical bistable devices using composites of zinc sulfide nanoparticles and poly-(N-vinylcarbazole)

N-dodecanethiol capped zinc sulfide（Zn S） nanocrystals were synthesized by the one-pot approach and blended with poly（N-vinylcarbazole）（PVK） to fabricate electrical bistable devices. The corresponding devices did exhibit electrical bistability and negative differential resistance（NDR） effects. A large ON/OFF current ratio of 104 at negative voltages was obtained by applying different amplitudes of sweeping voltage. The observed conductance switching and the negative differential resistance are attributed to the electric-field-induced charge transfer between the nanocrystals and the polymer,and the charge trapping/detrapping in the nanocrystals.

Design of an Electrically Written and Optically Read Non-volatile Memory Device Employing BiFeO3/Au Heterostructures with Strong Absorption Resonance

Exploiting new concepts for dense, fast, and nonvolatile random access memory with reduced energy consump- tion is a significant issue for information technology. Here we design an ＇electrically written and optically read＇ information storage device employing BiFeO3/A u heterostruetures with strong absorption resonance. The electro- optic effect is the basis for the device design, which arises from the strong absorption resonance in BiFeO3/Au heterostructures and the electrically tunable significant birefringence of the BiFeO3 film. We first construct a sim- ulation calculation of the BiFeO3/Au structure spectrum and identify absorption resonance and electro-optical modulation characteristics. Following a micro scale partition, the surface reflected light intensity of different polarization units is calculated. The results depend on electric polarization states of the BiFeO3 film, thus BiFeO3/Au heterostructures can essentially be designed as a type of electrically written and optically read infor- mation storage device by utilizing the scanning near-field optical microscopy technology based on the conductive silicon cantilever tip with nanofabricated aperture. This work will shed light on information storage technology.

The Research and Application of the Anti-Interference Techniques of Electronic Device in Power System

This paper presents the study and application of the electronic device anti-interference techniques underhigh voltage and/or heavy current electro-magnetic circumstance in power system.[

Real-time and wearable functional electrical stimulation system for volitional hand motor function control using the electromyography bridge method

Voluntary participation of hemiplegic patients is crucial for functional electrical stimulation therapy.A wearable functional electrical stimulation system has been proposed for real-time volitional hand motor function control using the electromyography bridge method.Through a series of novel design concepts,including the integration of a detecting circuit and an analog-to-digital converter,a miniaturized functional electrical stimulation circuit technique,a low-power super-regeneration chip for wireless receiving,and two wearable armbands,a prototype system has been established with reduced size,power,and overall cost.Based on wrist joint torque reproduction and classification experiments performed on six healthy subjects,the optimized surface electromyography thresholds and trained logistic regression classifier parameters were statistically chosen to establish wrist and hand motion control with high accuracy.Test results showed that wrist flexion/extension,hand grasp,and finger extension could be reproduced with high accuracy and low latency.This system can build a bridge of information transmission between healthy limbs and paralyzed limbs,effectively improve voluntary participation of hemiplegic patients,and elevate efficiency of rehabilitation training.

Re-evaluation of Transvenous Lead Extraction with Modified Standard Technique: A Prospective Study in 229 Patients

As new-type powered sheaths are expensive and unavailable, the standard lead extraction techniques remain the mainstay in clinical applications in many countries. The purpose of this study was to re-evaluate the clinical application of the standard lead extraction techniques and equipment, and make some procedural modifications and innovations. In our center, between January 2006 and May 2012, 229 patients （median, 66 years） who underwent lead extraction due to infection and lead malfunc- tion were registered and followed up prospectively with respect to clinical features, reasons for lead ex- traction, technical characteristics, and clinical prognosis. A total of 440 leads had to be extracted trans- venously by using special tools from 229 patients （male, 72.1%）. Vegetations 〉1 cm were detected in six patients. Locking Stylets were applied for 398 （90.5%） leads. Telescoping dilator polypropylene sheaths and counter traction technique were used for 202 （45.9%） leads due to lead adhesion, and the mean im- plant duration of the 202 leads was longer than the other 238 leads （48.9±22.6 vs. 26.6±17.8 months; P 〈0.01）. In addition, modified isolation and snare techniques were used for 56 leads （12.7%）. Minor and major procedure-related complications occurred in three （1.3%） and four （1.7%） cases respectively, in- cluding one death （0.4%）. Severe lead residue occurred in one case. Complete procedural success rate was 96.1% （423/440）, and clinical success rate was 98.9% （435/440）. The median follow-up period was 18 （1-76） months. No infection- and procedure-related death occurred in our series. Our data demon- strated that high clinical success rate of transvenous lead extraction can be guaranteed by making full use of the standard lead extraction techniques and equipment with individualized modifications.

The Major Educational Issues in China

Adopting the method of literature consultation and logical analysis, this thesis analyses the major educational issues in China. Research shows: the curriculum provision should consider not only the national culture but also the interest or need of students; the new electrical devices can be positive tools for studying if making good use of them; the requirements of graduation should cover all the fields of a student in campuses; society and enterprise should focus more on student's ability; the college should offer more scholarships for poor students.

Model Analysis of Initial Hydration and Strueture Forming of Portland Cement

The auto efficiently hydration heat arrangement and the non-contacting electrical resistivity device were used to test the therrnology effect and the resistivity variation of Portland cement hydration. The structure forming model of Portland cement initial hydration was established through the systematical experiments with different cements, the amount of mixing water and the chemical admixture. The experimental results show that, the structure forming model of cement could be divided into three stages, i e, solution-solution equilibrium period, structure forming period and structure stabilizing period. Along with the increase of mixing water, the time of inflexion appeared is in advance for thermal process of cement hydration and worsened for the structure forming process. Comparison with the control specimen, adding Na2SO4 makes the minimum critical point lower, the flattening period shorter and the growing slope after stage one steeper. So the hydration and structure forming process of Portland cement could be described more exactly by applying the thermal model and the structure-forming model.

Energy Transfer from Ce^3＋ to Eu^2＋ in LiSrBO3 and Its Potential Application in UV-LED-Based White LEDs

Ce3＋/Eu2＋ codoped LiSrBO3 phosphor is synthesized, and its luminescent characteristics are investigated. LiSrBO3：Ce3＋,Eu2＋ phosphor exhibits varied hues from blue to white and eventually to yellow by resonance-type energy transfer from Ce3＋ ion to Eu2＋ ion and tuning the relative proportion of Ce3＋/Eu2＋ properly. Energy transfer mechanism in LiSrBOa：Ce3＋, Eu2＋ phosphor is dominated by the dipole-dipole interaction, and the critical distance of the energy transfer is estimated to be about 2 nm by both spectral overlap and concentration quenching methods. Under UV radiation, white light is generated by coupling 436 and 565nm emission bands attributed to Ce3＋ and Eu2＋ radiations, respectively.

Photoluminescence of a ZnO/GaN Heterostructure Interface

Growth of a ZnO/GaN heterostructure is carried out using pulsed laser deposition. By etching the ZnO layer from the ZnO/GaN structure, the photoluminescence （PL） of the associated GaN layer shows that the donor- acceptor luminescence of CaN shifts to about 3.27eV, which is consistent with the electroluminescence （EL） of n-ZnO/p-GaN already reported. XPS shows that oxygen diffuses into the CaN crystal lattice from the surface to 20nm depth. The PL spectra at different temperatures and excitation densities show that oxygen plays the role of potential fluctuation. The associated PL results of the interface in these LEDs could be helpful to understand the mechanism of EL spectra for ZnO/CaN p-n junctions.

Second Harmonic Detection of Spin-Dependent Transport in Magnetic Nanostructures

Detection of the second harmonic response of magnetic nanostructures to an ac current is shown to be a very sensitive probe of the magnetization reversal process. A temperature oscillation is obtained by Joule heating instead of using a laser as the heat source, as in thermo-galvanic voltage measurements （TGV）. Joule heating is used to produce a large local temperature gradient in asymmetric Co/Cu/Co spin valves. Evidence is found for an effect of a heat current on magnetization.

Research on Integrated Monitoring and Prevention System for Stray Current in Metro

On the basis of analyzing the influencing factors and harmfulness of stray current, and discussing the existing problems of monitoring and prevention system for stray current, the integrated monitoring and prevention system for stray current in metro was developed. A net system of distributed computers for monitoring was set up. It can monitor the distribution of stray current in metro and the corrosion of the metal structure in the whole line. According to the situation of monitoring it can also control the drainage of its tank to reach the best effect and eliminate the negative effect of polarity drainage. By using the new type unilateral electric device, the problem of burning the rail by electric arc can be avoided. The unilateral electric device can be connected with the monitoring net system directly to realize the monitor in line and improve the reliability of the device.

Experimental Verification of Left-Handed Metamaterials Composed of Coplanar Electric and Magnetic Resonators

We verified experimentally left-handed metamaterials （LHM） composed of coplanar electric and magnetic resonators. A typical LHM sample composed of coplanar resonator unit cells was fabricated, investigated and tested. The experimental results show that the tested sample has a left-handed band of width 1.4 GHz in the X band. The experimental results agree quite well with the simulation ones. Moreover, both the simulation and experimental results show that the LHM under study can automatically achieve good impedance-matching in the left-handed band.

Ultraviolet Sensitive Ultrafast Photovoltaic Effect in Tilted KTaO3 Single Crystals

An ultraviolet sensitive ultrafast photovoltaic effect is observed in tilted 10° KTaO3 （KT） single crystals. The rise time of the transient photovoltaic pulse is 497.4 ps and the full width at half maximum is 974.6 ps under irradiation of a 266 nm laser pulse with 25 ps duration. An open-circuit photovoltage sensitivity of 328 mV/mJ and a photocurrent sensitivity of 460 mA/mJ are obtained. The experimental results demonstrate the potential applications of KT single crystals in ultraviolet detection.

Micromagnetic Simulation of Transfer Curve in Giant-Magnetoresistive Head

The transfer curve of the giant-magnetoresistive （GMR） magnetic head represents its most important property in applications, and it is calculated by the micromagnetic modeling of the free layer and the pinned layer in the heart of the GMR head. Affections of the bias hard magnetic layer and the anti-ferromagnetic pinning layer are modeled by effective magnetic fields. The simulated transfer curve agrees with experiment quite well, therefore the values of these effective magnetic fields can be determined by the model. A synthetic antiferromagnetic spin valve structure GMR head is also analyzed for comparison.

Three-dimensional vertical ZnO transistors with suspended top electrodes fabricated by focused ion beam technology

Three-dimensional(3D)vertical architecture transistors represent an important technological pursuit,which have distinct advantages in device integration density,operation speed,and power consumption.However,the fabrication processes of such 3D devices are complex,especially in the interconnection of electrodes.In this paper,we present a novel method which combines suspended electrodes and focused ion beam(FIB)technology to greatly simplify the electrodes interconnection in 3D devices.Based on this method,we fabricate 3D vertical core-double shell structure transistors with ZnO channel and Al_(2)O_(3) gate-oxide both grown by atomic layer deposition.Suspended top electrodes of vertical architecture could be directly connected to planar electrodes by FIB deposited Pt nanowires,which avoid cumbersome steps in the traditional 3D structure fabrication technology.Both single pillar and arrays devices show well behaved transfer characteristics with an Ion/Ioff current ratio greater than 106 and a low threshold voltage around 0 V.The ON-current of the 2×2 pillars vertical channel transistor was 1.2μA at the gate voltage of 3 V and drain voltage of 2 V,which can be also improved by increasing the number of pillars.Our method for fabricating vertical architecture transistors can be promising for device applications with high integration density and low power consumption.

Integrated Heat and Power Dispatch Model for Wind-CHP System with Solid Heat Storage Device Based on Robust Stochastic Theory

This paper built a combined heat and power（CHP） dispatch model for wind-CHP system with solid heat storage device（SHS） aiming at minimizing system coal consumption, and set system demand-supply balance and units＇ operation conditions as the operation constraints. Furthermore, robust stochastic optimization theory was used to describe wind power output uncertainty. The simulation result showed that SHS increased CHP peak-valley shifting capability and reduced abandoned wind rate from 12% to 6%, and reduced 5% coal consumption, compared with the original system operation by flexible charging electric power and heating. The payback period of employing SHS in wind-CHP system is far shorter than SHS expected service life.

A Review of Series Voltage Source Converter with Fault Current Limiting Function

The series voltage source converter(SVSC)is widely used in the power electronic equipment,such as series active power filter,dynamic voltage restorer,unified power flow controller and so on.However,while the SVSC is more vulnerable to the impact of fault current,its applications are increasing,bringing huge challenges to the safe operation of the grid.In recent years,the topology and control strategy of the series voltage source converter with fault current limiting(SVSC-FCL)are a research hotspot.In this paper,it suggests classifying SVSC-FCL based SVSC into two groups:the control scheme optimization group and the existing topology improvement group.The research challenges and perspectives of the SVSC-FCL are introduced in detail.This paper aims to illustrate current research progress on SVSC-FCL and enrich the available pool of the multi-functional power electronic equipment.