Showing papers in "Journal of Qingdao University in 2011"

Experimental Study of Thiourea Leaching Gold and Silver from Waste Circuit Boards

Abstract: Waste circuit boards contain a rich resource of recoverable metals such as Cu,Au,Ag,Pt,and Pb.Its disposal,harmless and recycling have become the key problems solved urgently with the economic development.Thiourea leaching gold and silver from the waste circuit board was carried out,and the influence of leaching time,react temperature,thiourea concentration,Fe3+ concentration and material particle size on gold leaching rates were investigated.The results showed that,Gold and silver leaching rates can reach the best results under the best canditions,and the highest leaching rates of gold and silver were 90.87% and 59.82%,respectively.Thiourea leaching gold has the advantages of quick leaching speed,low-toxic,low-cost,high efficiency,environmental friendly,less interference ions,and it is becoming green leaching gold method to replace cyanide leaching gold.

Fuzzy H_∞ Filter Design for Nonlinear Systems with Delays

Abstract: This paper focuses on the problem of fuzzy H∞ filter design for nonlinear delayed systems.A new approach of filter design is proposed by using Lyapunov stability theory together with linear matrix inequality(LMI) approach and free-weighting matrix technique.Some sufficient conditions for the existence of fuzzy H∞ filter is established based on the solvability of a set of LMIs.A numerical example is used to illustrate the effectiveness of the proposed method.

Method of Rolling Bearing Fault Diagnosis Based on Wavelet Singularity

Abstract: In the research of fault diagnosis of rolling bearing,the fault is usually accompanied with signal discontinuity.So it is greatly important to detect the singularity of signal.This paper introduces the theory of wavelet transform and wavelet transform singularity detection theory,and studies the method of singularity detection in the application of rolling bearing fault diagnosis.Threshold de-noising method based on wavelet transform is applied to deal with vibration signal of rolling bearing.And then the method of the singularity detection of modulus maximum is used to make the multi-scale analysis of the de-noised signal.At last the location of the fault is acquired.The experimental results show singular degree of vibration signals and location of singular points are obvious.

Group Signature Scheme Based on BLS Short Signature

Abstract: A new constructive method of dynamic group signatures was presentedBased on BLS short signature,a short and simple scheme of group signatures was proposed by introducing two group managersOne is responsible for the join of the group member and the distributions of the key;another manages the tracing of the group signatureResults of security analysis show that this scheme can satisfy the security requirements of a group signature

Port-Controlled Hamiltonian Control of PMSM Based on Back to Back Four-Quadrant Converter

Abstract: For the drive system incorporated with back-to-back voltage source converter and PMSM(permanent magnet synchronous motor),four-quadrant operation of the motor is studied based on energy shaping and PCH(port-controlled Hamiltonian) system theory and traditional PI control scheme.A double closed loop vector control strategy with improved load current feedforward is presented for the grid side converter,and a state error port-controlled Hamiltonian control method is proposed for the machine side converter.According to coordinated control strategy for the grid side and the machine side,the control objectives are achieved that energy is bidirectional flow,the DC bus voltage is adjustable,the power factor is one,and the motor can run in four-quadrant state.Finally,the effectiveness of control strategies is verified by simulation results.

A Temperature Monitoring System Based on PSoC

Abstract: The traditional design of the temperature monitoring systemis complex and not conducive to small.In view of the above shortcomings,the design in this paper is based on PSoC microcontroller chip CY8C29466 and programmed by PSoC Designer.It uses the analog temperature sensor LM35 as a chip tomeasure temperature.Results show that the design has the advatage of si mplicity,flexiblity and high reliability.In the field of embedded this design will be widely used.

An Adaptive Inventory Control for a Multi-Period VMI Model with Non-Stationary Demand

Abstract: With more and more uncertainties appeared in supply chains,the VMI inventory management as a new inventory control approach was concerned by more and more businesses and academicians.In this paper,a VMI inventory control model for a two-stage supply chain consisted of one supplier and one retailer was proposed.For non-stationary demand,an adaptive inventory control method was proposed.In this approach,the secondary exponential smoothing method was used to forecast the demand,and the reinforcement learning was adopted to evaluates the effect of the adopted safety factor,and then to adjust the level of customer service.Simulation results show that the proposed adaptive inventory control scheme can get a very satisfied service level for different non-stationary demand mode.

Impacts of Government Expenditure on China's Industrial Structure Upgrading:Based on Provincial Panel Data from 1978 to 2006

Abstract: Based on the data of 29 provinces from 1978 to 2006,the impacts of governncent expenditure and stracture on china's industrail upgrading is analyzed with the CD function by insertiug government expenditure.Results show that government expenditure of culture,education,science and public health promote the upgrading of industrial structure,and the rest of the government expenditures shows various effects on industrial structure upgrading,some of them even have adverse impact on industrial structure upgrading.

Study on the Suitability for the Hamrock-Dowson Formula Under Heavy Load and High Speed Working Conditions

Abstract: Using new lubrication oil,the suitability for the Hamrock-Dowson formula under heavy load and high speed working conditions were discussed.It was concluded that Hamrock-Dowson formula was not suitable under heavy load and high speed working conditions,and the numerical results may vary from two to four times than that of Hamrock-Dowson formula results.With the developments of EHL theory and computing technique,the lubricating design should rely on computing software and experimental technique rather than experimental formula.

A Partial Trade Credit Model with Cash Discount Under Supply Chain Management

Abstract: The retailer's inventory policy was studied under two levels of trade creditAssuming that the retailer has dominion,and obtain a full credit offered from the supplier,the customer can only get a partial trade credit offered from retailer,the retailer's annual cost model was established according to the different credit period,and retailer's optimal inventory policy was given by the cost minimization

Electroless Copper Composite Plating on PET Fabric by Using Different Nano Particles

Abstract: Nano-particles of ZnO,Si3N4,Fe3O4,ZrC and SiO2 were dispersed in the solution of Tween 80 at first,and then were added to the copper plating solutions,respectively.The Cu-ZnO,-Si3N4,-Fe3O4,-ZrC and-SiO2 plating on PET fabrics were prepared in the laboratory.The plated fabrics were investigated by means of SEM,EDS,XRD and TG.The abrasion resistance and electromagnetic shielding performance were also measured.The results show that as compared with the Cu-plated fabric,the surface roughness of Cu composite plating increases but the holes decrease distinctly.The structure and the onset decomposition temperature of the composite Cu-plated fabric change a little.The grain sizes are different from each other.The shielding effectiveness changes slightly but the abrasion resistance becomes worse.The shielding effectiveness increases with increasing the weight increasing percentage,but the surface resistance decreases at first,and then reaches to a certain level.

Investigation on Synthesis of Poly(N-vinylcaprolactam)

Abstract: Poly(N-vinylcaprolactam)(PVCL) was synthesized based on free-radical polymerization mechanism through solution polymerization,precipitation polymerization and dispersion polymerization respectively,using azodiisobutyronitrile(AIBN) as initiator and N-vinylcaprolactam(VCL) as monomer.The chemical structure of prepared PVCL was verified by infrared spectrometry(FTIR).The intrinsic viscosity of PVCL was measured by viscosity method.The effects of reaction conditions on the intrinsic viscosity of PVCL and conversion of VCL were studied.It is shown that under solution polymerization,the dosage of ethanol: 30 mL,nAIBN/nVCL: 2%,t: 4 h,T: 75 ℃;and under precipitation polymerization,the dosage of waterl: 35 mL;and under dispersion polymerization,mSA: 0.7 g,the intrinsic viscosity of PVCL and conversion of VCL got the maximum.The prepared PVCL exhibits good temperature-sensitivity,with the low critical solution temperature around 33 ℃ measured by spectrophotometer.

Reason and Countermeasure Research About Domestic Funds Tend to Real Estate Speculation

Abstract: In recent years,the price of property ever rising,the investors treat the property purchasing as a speculative toolThe reasons for the funds tending to real estate speculation are non-perfect housing security system,the lack of effective invest method,the high earning of the real estate investment,the connivance of local government,the greedy of developers,the non-geographical restrictions for financial market and human resources and tax deficiencies for real estateIn response to these questions,the government should change the policy direction,formulate housing security law,broad the investment channel and crack down on speculation in the housing market by using monetary policy to control prices and taxation policy to curb price

A Study on BPT Algorithm Weighting to the SIRT Algorithm

Abstract: A weighted algorithm was put forward for SIRT algorithm of acoustic tomographySlowness distribution regarded as the initial value was firstly obtained by BPT algorithmThe difference of slowness between each point of space and the average was seen as the weighting coefficient of the ray matrix in the SIRT algorithmThe example shows that the improved algorithm was a feasible weighting algorithm as maintaining the convergence of the SIRT algorithm,speeding up the convergence rate of SIRT algorithm,improving computational efficiency and particularly the accuracy

Research on Application of Principal Component Analysis in Computer Color Matching for Textile Dyeing

Abstract: To get the relationship of textile dye recipe and three stimulus values,by analysis with the experimental data,multiple nonlinear model of dye recipe and three stimulus values of C,M and Y is established in this paper based on Principal Component Analysis.Combined with curve fitting and surface fitting,the nonlinear equations with parameters can be got,and then the Newton iterative method can be used to solve the nonlinear equations in order to get the dye recipe.The experimental results show that,using the principal component analysis to establish the corresponding mathematical model,the values of the dye recipe and the actual values are very close,which can meet the requirements of the actual dyeing color matching.

Improved Simulation for Sensorless Vector Control System on MRAS

Abstract: The speed sensorless vector control system was established based on the fundamental equations of induction motor for vector control.This paper proposes a novel scheme for a speed sensorless vector control system of induction motor based on MRAS.As the traditional MRAS uses pure integrator,which results in accumulated error and DC offset problem easily,the paper presents the improved integral model rotor flux estimation model by increasing filter.On the platform Matlab/Simulink,the system was simulated.Simulation results show that the motor speed error is approximately 1%,and the system has better dynamic performance and better load disturbances attenuation.

Warning Mechanism Model of Online Public Opinion Based on System Dynamics

Abstract: Based on the AHP and system dynamics,a system dynamic model for warning mechanism of online public opinion was built.The model was analyzed from the relationship between government and network media by qualitative and quantitative.The model was simulated by using VENSIM.Results show that such method can improve the accuracy of early warning of public opinion,reduce the cycle time and weaken its harmfulness by enhancing the government credibility and strengthening the supervision of network.