bluuebunny/crossref_metadata_2025 huggingface dataset:
The Problems of Mobile E-Commerce Secure Payment and Solutions
Authors: Peng Xiang Jun , Chen Juan Juan
Published: October 2013

The payment system of wireless communication is a whole of the various types of software used by the wireless communication network, wireless payment terminals and payment terminals, which together constitute the user applications. Compared to traditional network, wireless communication network is an more open system. According to this, users personal is easier to be stolen in the transfer process and the type of attack has become more diverse and innovative. The article introduces two types attack and solutions. Fishing Wifi is a common means of attack in the wireless network nowadays. Mobile banking is a typical example too. It involves the security of payment in mobile banking which becomes the new problem within e-commerce.
Watermarking Algorithm Based on Informed Coding and Informed Embedding
Authors: Wang Xin , Liang Chao , Liu Zhi Gang
Published: October 2013

Informed coding and informed embedding have received considerable attention as a method of digital watermarking with side information in resent years. We designed a new type of codes called structured dirty-paper trellis in which each message is replaced by amount of alternative vectors. This method is very efficient to prevent brightness scaling. A Viterbi decoder is used in the detecting part to find out the highest correlation path. The correct message will be detected no mater how the brightness has been changed for it has no relativity with brightness. In embedding part, watermarking message is adapted by SNR. The original image is divided into several blocks which are transformed by DCT and the adaptive parameter is calculated based on SNR for each block, then watermarking components with different strength are inserted into some middle-frequency coefficients. The experimental results demonstrate that the watermarks generated with the proposed algorithm in this paper have good imperceptibility and robustness.
The Application of Carbon Fiber Materials in Sports Equipment
Authors: Tang Dao Zhi
Published: October 2013

In order to build a resource-conserving and environment-friendly society, advocate a green sports and to be a truly ecologically sustainable development, the carbon fiber composite materials will be applied to the field of sports equipment manufacturing, which is an effective and economic way to protect the environment. This paper focuses on the performance advantages of carbon fiber composite and analyses its application in sports equipment. At the same time, it mainly discusses its application advantages of carbon fiber composite materials in sports equipment and illustrates some application examples, finally, summarizes the research status of carbon fiber composite materials at home and abroad.
FRSTM Fracture-Based Pre-Stack Elastic Wave Impedance Inversion of Fuyang Oil Layer in Songliao Basin
Authors: Zhang Xin Rong , Fang Shi , Liu Jin Ping , Yang Mao Xin
Published: October 2013

The later-period structure of Fuyang oil layer is complex and its reservoir is mostly composed by the sand bodies of riverways. The oil and gas reservoir features obvious concealment, and also is difficult to identify. To accurately describe the reservoir, a pre-stack elastic wave impedance inversion was made for Fuyang oil layer in Songliao Basin using FRSTM fracture. The pre-stack inversion results statistical error was small if the thickness of sandstone was greater than 3m. The error was close to 100% according to the standard less than 20%, namely the pre-stack inversion prediction accuracy was higher. However, the statistical error was greater and the pre-stack inversion prediction accuracy decreased if the thickness of sandstone was less than 3m, so the prediction result could be only used as a reference value. Therefore, the pre-stack elastic wave impedance inversion can produce a significant effect for the anisotropic reservoirs of complex later-period structure, thin sand body, and complex changes, and can meet the needs of the oil field exploration and development.
Logistics Park Distribution System Paths Optimization Problems Based on Cloud Computing
Authors: Zhang Ying , Gao Min , Liu Yan Qiu
Published: October 2013

In order to study the distribution system of the logistics parks with the support of cloud computing, the paper analyzes the distribution of goods under the conditions of the massive resources and real-time information assisting problem. When the distributed system selecting the paths in massive resource planning for each scheduling, it increases the number of paths selection and reduces transportation costs.. This paper uses the mathematical programming and optimization theory to establish an optimal mathematical model of costs and time for the target path, and introduce the optimal solution of the genetic algorithm. This paper demonstrates through an example application that this model is efficient and embodies the advantages of cloud computing in logistics applications.
The Impact Analysis of Local Protectionist Based on Set Pair Analysis
Authors: Yang Ya Feng , Li Li Hong , Liu Bao Xiang
Published: October 2013

Local protectionism is a barrier to the sound development of the market economy. To analysis the impact and effectiveness of local protectionism from the angle of mathematic or system science, this paper analysis the connection function of local economy system based on set pair analysis method and the basic ideas of Jieke Theory. Then, the negative impact of local protectionism was discussed according to the connection function between regional economies. Finally, some suggestions were given.
The Design Research for the Desk and Chair Basing on the Human Body Comfort and Applicability
Authors: Wang Xiang Rong , Xue Cheng Qi
Published: October 2013

This paper made the investigation and analysis to the desk and chair for the primary and secondary students. So from the ergonomics and product semantics,mechanical principle, design psychology as the starting point, also basing on the satisfaction for the economic costs and environmental protection and others, we had design a set of chair and desk accord with the ergonomics, which can keep the normal physiology curve of students and good for growing, but also can improve the learning efficiency. This design method is one of the important development directions of desk and chair in the future, also has important reference significance on the ordinary design for desks and chairs.
The Research for Cost Control in Customized Production of Machinery Products
Authors: Zhu Shi Zhao , Zou Qi , Ji Shuai Xian
Published: October 2013

Due to the increase of uncertainty and complexity of the market, the demand level of machinery enterprises upgrades. The demand structure is diversified, and the lifecycle of mechanical products is getting shorter. All these pose great challenges to the production management and control. In recent years, machinery textile industry is developing rapidly. Textile processing is moving in the direction of multi-varieties, small batch and short-cycle. Textile manufacturers need to sustain innovations. After completing the design, textile designers should make a proof in accordance with user requirements and then decide whether to put into production.
Software Saber Used to Worst Case Analysis of On-Satellite Switching Power Supply
Authors: Zhang Qian , Liu Ke Cheng , Li De Quan
Published: October 2013

The worst case analysis by means of software Saber is implemented on a three-output flyback switching power supply. The analysis results offer a criterion to definite error range of the device parameters.
Coal Bed Methane Reservoir in the Mengjin Coalfield, Henan Province, China
Authors: Lian Jin Jiang , Yan De Tian , Gao Biao , Cao Hai Yang
Published: October 2013

Coal is a continuous unconventional gas reservoir and coal bed methane has the potential to make an important contribution to the future energy demands. The second member coal seam of Shaxi Formation in the Mengjin coalfield is one of the most important methane bearing and exploration formations. Based on industrial analysis, elemental analysis and methane content test of thirty-five coal samples from the Mengjin coalfield, together with other geological data of the past five-year exploration, the factors that controlling the coal bed methane reservoir are identified in the Mengjin coalfield. The thick-bedded No. 2 coal seam, about 6 meters, of the Shaxi formation are continuous distributed in the Mengjin coalfield. The burial depth is from 400 to 800 meters, this is suitable for coal bed methane exploit. There is a trend which an increase in the degree of coalification is correlated with rise content of methane in No. 2 coal. Coal rank has a significant effect on the content of coal bed methane. The relationships between methane content and basin hydrodynamics are also described and discussed in this paper. The deep stagnant zone contains the largest coal bed methane accumulation. Future geological exploration for coal bed methane in Mengjin coalfield should be guided by the essential factors identified in this study. The application of them could benefit to solving the discrepancy between the amount of reserves and the question of their exploitability.
Removal of Oil from Movie Shooting by EPDM Foaming Material
Authors: Zhang Yi Fei , Bian Fei , Song Rong Guang , Zhang Guo
Published: October 2013

Movie shooting caused large quantities of oil emissions into the surrounding frequently , the water quality could be contanminate. EPDM rubber was chosen as the main matrix to prepare foam oil absorption material by simple melt blending and molded foaming. The impact of DCP and AC on oil-absorbing properties of materials was studied, and the optimal amount of DCP and AC was 1.5Phr and 10Phr; Through foaming process, the oil absorbency was greatly improved, and the maximum oil absorbency was 12.73g/g which was increased by 566.5% compared to the corresponding solid material. This composite is an inexpensive, convenient and high efficiency material for removing oils from movie shooting.
Rapid Analysis of Table Grape Maturity Based on Color Difference
Authors: Zhu Danshi , Wu Xiao Fei , Zhang Qiao Man , Meng Xian Jun , Li Jian Rong
Published: October 2013

Color of grape berry changed a lot during ripening that might reflect the maturity of table grape. In this study, the color difference of Kyoho grape skin was analyzed by CR-400 chroma meter, and the value of L*, a* and b* were measured at different stages of maturity. The results showed that the value of L* and b* decreased along with maturity, which reflected in the color of the grape skin turning darker and bluer. In addition, the value of a* increased continuously until 80% maturation and then decreased after this stage of ripeness. Results of correlation analysis showed that the value of L*, a*, b* and maturity were highly correlative (p < 0.01). Maturity was significant negatively related to L* and b*, and positively related to a*. There was negative correlation between a* and L*, b*, while significant positive relation between L* and b*.
Intensification of Ammonia Removal from Drinking Water with a Modified Zeolite Biological Filter Reactor
Authors: Tang Hui , Li Ming Yu , Diao Zeng Hui
Published: October 2013

A novel modified zeolite bio-filter reactor was used for ammonia removal from drinking water, and inoculated nitrobacteria was combined with modified zeolite in this bio-filter reactor. The effects of various operation factors on the performance of the modified zeolite bio-filter reactor were investigated. The optimum operation conditions of the modified zeolite bio-filter reactor were obtained as follows: a HLR of 0.9 m3/ (m2.h), the temperature ranged from 15°C to 30°C, and no-aeration. Under these optimal conditions, the outlet concentration of ammonia was less than 0.5 mg/L, even when an initial ammonia concentration of 6 mg/L.
Simulation of Deep Percolation in Fields with Greater Depth of Groundwater
Authors: Du Zhi Da , Shao Long Tan
Published: October 2013

The rules of deep percolation produced by irrigation under maize in the field with greater depth of groundwater are studied. With the maize cultivation in Dalian as an example, 1-D finite element model is built by VADOSE/W using the daily meteorological data in the years with guaranteed rainfall frequency of 75%, 50% and 25% through analyzing the years-long period regional meteorological data. By this model, the field soil water flow in a whole year under the rain-fed, sprinkler irrigation and border irrigation is simulated respectively, and the water balance of 1m-deep root zone is analyzed. The simulation shows that the ratio of deep percolation to the sum of net precipitation and net irrigation water amount is less than 5% under the rain-fed, 5%~9% under the sprinkler irrigation, 7%~13% under the border irrigation respectively. 70%~95% of deep percolation is produced by irrigation and about 13%~28% of net irrigation water amount is lost as deep percolation, as a result, the main reason for deep percolation can be concluded as irrigation in fields.
Bromide Ion Removal by Coagulation in Drinking Water
Authors: Zhu Qi , Liu Dong Mei , Cui Fu Yi , Fang Lei
Published: October 2013

In order to prove the rules of bromide ion remove in coagulation treatment stage in drinking water, by carrying out laboratory coagulation test in simulated water and the Songhua River raw water samples, the effects of bromine ion removal by coagulation of PAC, FeCl3 and the compound ferrous were investigated. The results showed that when the dosage of PAC was 60mg/L, the average removal rate of bromine ion was 50.6% by coagulation in the simulated water samples, and the rate was 44.8% in raw water samples of the Songhua River. In the conditions of FeCl3 dosage 70mg/L, the average removal rate of bromine ion was 56.1% in the simulated water sample, and the rate was 55.2% in raw water. When Reduce the same turbidity of drinking water, the effect of bromide ions removal by FeCl3 coagulation was better than that of PAC. When the dosage of compound ferrous (Ferrosilicon ratio of 1:1) as coagulant was 16.8mg/L, the bromide ions removal rate up to 67.6%.
Practical Application of ICT Solutions for Energy and Water Savings at Condominium Level
Authors: Fernández-Agüera Jesica , Domínguez Samuel , Campano Miguel Angel
Published: October 2013

EnergyTIC project has made available easy ICT ́s solutions for domestic end users in order to involve the social housing residents as an active part of water and energy efficiency. In this paper we analyze a proposal for a methodology designed to apply these single home ICT technologies in the whole-building energy layer. Our approach treat to take advantage of the the system currently in operation at single-dwelling level in order to involve users in the same building as clusters of the energy and water savings at building level. An on-line continuous benchmarking process between buildings in the same area will be used as the main tool of our procedure.
Economic Analysis of Water-Saving Device with Higher Efficiency Replacement -- Taking Beijing as an Example
Authors: Lue Jian , Si Qi , Guan Qing Kun
Published: October 2013

Water device is the end of water supply system, its water saving performance of construction plays a key role in the water saving in building[. We test the water-saving performance of various device by the "water saving performance testing device" which is developed independently by our group, analysis the flow characteristics at different conditions. It can apply view for consumers to choose qualified water-saving appliances in the future[2].
Efficiency of Sensor Devices Used in Dynamic Solar Tracking System: Comparative Assessment Parameters Review
Authors: Balogun Emmanuel B. , Huang Xu , Tran Dat
Published: October 2013

There have been recent research interests in obtaining an optimum efficient design for the solar tracking system in published papers over the past three decades. This paper presents an in-depth overview of the assessment parameters and characteristics of various sensor devices employed to provide precise feedback control mechanism used in dynamic solar tracking systems. We found that the webcam sensor device has superior capability compared to other solar sensors devices. In conclusion, we propose a future research direction for a better efficiency and effective dynamic solar tracking system. Keywords: Solar tracking; Solar sensors; Solar panels; Overall output generated energy; Webcam; Photoresistors; Photodiodes; Feedback Control mechanism
A Study on the Micro Heat Pipe Array Based Flat Plate Solar Heating System
Authors: Yang Jin Gang , Xu Jia Qi
Published: October 2013

The application system of solar energy comprises: solar water heating system, solar heating system and solar photovoltaic system, etc. The data monitoring system used in the solar water heating system consists of measuring and monitoring equipment, data acquisition appliances and data-center softwares. The measuring and monitoring equipment includes outdoor temperature sensor, total solar irradiance sensor, water inlet and outlet temperature sensor of heat collecting system, circulating flow sensor of heat collecting system and the electric meter for supplementary heat source, etc.. The data monitoring system used in the solar photovoltaic system consists of measuring and monitoring equipment, data acquisition appliances and data-center softwares. The measuring and monitoring system is composed of outdoor temperature sensor, total solar irradiance sensor, the sensor for the surface temperature of back panel of solar photovoltaic modules and electric meter for the monitoring of power generation of solar photovoltaic system, etc.
Evaluation of Large-Scale PV Generation of Baicheng District in Western Jilin Province
Authors: Feng Li Min , Yan Gan Gui , Wang Ze Hui , Yao Zhi Zhong
Published: October 2013

This paper evaluated the solar energy resource of Baicheng district in western Jilin province with HOMER simulation software. The results show that the solar energy resource of Baicheng district is quite abundant and relatively stable. This paper analyzed the current situation of PV generation in Baicheng district, considered that Baicheng district is suitable for large-scale PV generation projects and put forward some reasonable advice.
Performance Detection Device of Solar Lighting System Based on LABVIEW
Authors: Cui Yan , Pan Shi Lian , Zhao Jian
Published: October 2013

Although the Chinese solar semiconductor lighting industry has been developing rapidly, the detecting technology of this has developed slowly. Therefore, the performance testing device of solar lighting system would be practical significant. In view of this, this paper was mainly using the Hall current sensor, USB data acquisition card and other components to build a solar lighting system detection device. During the actual testing, the system can monitor and evaluate the real-time performance of the photovoltaic street lighting system very well, and achieves the desired effect.
Exergy Analysis of Solar Photovoltaic/Thermal Organic Rankine Cycle
Authors: Zhao Guo Chang , Song Li Ping , Wang Yong , Hou Xiao Chen
Published: October 2013

A solar thermal organic Rankine cycle (ORC) power generation system model established using R245fa as the working fluid and coupled with a solar photovoltaic generator is introduced. Thermal efficiency and exergy efficiency of the model both with and without a heat regenerator are calculated and compared. Results show the solar organic Rankine cycle system with a heat regenerator has higher thermal and exergy efficiency than the system without a heat regenerator, providing better performance in practice. This result provides a basis for further application and improvement of solar photovoltaic and the solar thermal organic Rankine cycle.
Experimental Study on Solar Energy and Adsorption Radiation Air Conditioning System
Authors: Ji Amin , Wang Chang Jiang , Yu Yan , Zhang Chun Ying , Tian Tian
Published: October 2013

This paper discusses the principles of solar adsorption refrigeration and the characteristics of air conditioning radiation, designs solar adsorbent bed with activated carbon - methanol as working pair and its accompanying condenser, evaporator, radiant cooling tubes and other equipment. Through experiments, it changes water supply by change flow rate of chilled water, in order to get chilled water supply and return water temperature and room temperature curve. To analysis COP value of system under different flow rate of chilled water, and get the optimal flow rate of chilled water supply.
Research on Thermoelectric Coupling Characteristics of PV Modules
Authors: Zhang Yu , Bai Jian Bo , Liu Sheng
Published: October 2013

The paper presents the thermoelectric coupling model for a photovoltaic (PV) module. Firstly, the five-parameter electrical model and the thermal model of the PV module are investigated. In order to evaluate the effectiveness of the model, the numerical computation and experimental values under certain environmental conditions are compared. The experimental results demonstrate the model has reasonable accuracy. Furthermore, to investigate the PV modules performance under different ambient temperature, irradiance and wind speed, the model is used to simulate the thermoelectric characteristics of the PV module. The simulation results can provide meaningful method to predict power generation of the PV module under various conditions.
Screening of Key Genes Responsible for Ethanol Fermentation in Xylose-Metabolizing Yeast Strains
Authors: Cai Peng , Miao Yuan Yuan , Xiong Xu Jie , Xu Yong
Published: October 2013

Based on comparison analysis of transcriptome sequencing data, potential genes responsible for xylose fermentation to ethanol were screened and chosen from two model yeast strains of Candida tropicalis and Candida shehatae. Thereafter, key genes were indentified from these candidate genes by the combined method of quantitative real-time PCR detection and metabolism pathway analysis. These genes regulatory mechanism on sugar metabolic pathway were further investigated and illustrated. Four key genes responsible for xylose fermentation to ethanol are determined and confirmed finally as follows: xylose reductase, xylitol dehydrogenase, high-affinity glucose transportor and pyruvate kinase.
Effects of Mesophilic and Thermophilic Temperature on Hydrolysis and Acidification of Organic Wastes Two-Phase Anaerobic Digestion
Authors: Yang Shan Rang , Li Yong Zhen , Ding Yu Ming , Zhao Bo , Liu Zhi Chao , Pang Jun Hua , Wang Tian Hui , Shang Cong
Published: October 2013

This paper investigated the effects of mesophilic temperature (35°C) and thermophilic temperature (55°C) on the hydrolysis and acidification phase in the process of organic wastes anaerobic digestion. Here, the organic wastes refer to the mixture of corn straw and pig manure in this paper. The results show that pH value is negatively correlated with volatile fatty acids (VFAs) concentration, throughout the process both the VFAs concentration and its maximum of mesophilic temperature are bigger than that of thermophilic temperature, but it takes longer time to reach the maximum; the total solids (TS) removal rate of thermophilic temperature is 31.85% and the mesophilic temperature is 27.33%, but it needs to consume more energy to maintain a high temperature state. The above results suggest that the mesophilic is more advantageous than thermophilic temperature in the treatment of corn straw and pig manure co-digestion, but the post-disinfection treatment is needed.
Research Progress on Cellulose Degradation Bacteria Isolation and Utilization
Authors: Xu Cheng Jiao , Wang Ai Jie , Chen Lin Na , Cao Guang Li , Ren Nan Qi
Published: October 2013

Cellulose is regarded as a kind of biomass with high quantity, the proper utilization could realize energy recovery and high-value product recovery. Cellulose degradation is of great importance for its utilization. This article introduced the isolation, characteristic and the mutual effect of compound cellulose degradation bacteria, the composition, the effect and mechanism for cellulose hydrolysis were also introduced. Rumen microbial were taken as example for its utilization in cellulose degradation. The relationship between anaerobic and aerobic were discussed to evaluate their mutual effect. It is proved that the aerobic microorganism could help to provide the anaerobic condition for the bacteria, while the anaerobic could reduce the product inhibitor effect.
Thermogravimetric Analysis of Biomass Pyrolysis under Different Atmospheres
Authors: Cui Fang Ming , Zhang Xiao Yuan , Shang Li Min
Published: October 2013

Thermogravimetric analysis (TGA) was employed to study the effects of two different atmospheres (nitrogen and mixed biomass gasification gas) on the pyrolysis of rice husk, corn stalk and pine wood. Kinetic parameters were calculated based on the experiment data. The results indicated that TG and DTG curves moved to higher temperature range and the characteristic temperatures ascended as the increasing of the heating rate. Moreover, the three biomass materials exhibited similar pyrolysis behaviors under the two different atmospheres, but the activation energy values of the pyrolysis under mixed biomass gasification gas were higher than those under nitrogen.
Research on Catalytic Coupling of Cornus Wisoniana Oil for Biological Rich-Hydrocarbon Fuel
Authors: Xiao Zhi Hong , Zhang Ai Hua , Jiang Wei Wei , Li Yang , Zhang Hong Qin , Li Pei Wang , Li Chang Zhu
Published: October 2013

TheCornus wisonianaoils derives from the energy tree species, belonging to woody energy plant oils. This experiment studied the catalytic cracking decarboxylation reaction ofCornus wisonianaoil. Through experiments, CaO / KF made by ourselves was proved to be have good catalytic effect. The highest yield of liquid fuel oil products is at 83.0% or more. Because of high acid value, pyrolysis oil can not be directly burned, this study p-toluenesulfonic acid as a catalyst to conduct esterification alcohol, lower acid value. Then alcohol esterification was used to reducing acid of cracking bio-fuel products and p-Methylbenzene sulfonic acid as catalyst. After reducing the acid, this kind of fuel is closer than traditional fossil fuels, able to alternative to diesel, and to achieve energy conservation.
Comparison of Signal Smoothing Techniques for Use in Embedded System for Monitoring and Determining the Quality of Biofuels
Authors: Valadares Dalton Cézane Gomes , Drebes Rute Cardoso , Melcher Elmar Uwe Kurt , Espínola Sérgio de Brito , Araújo Joseana Macêdo Fechine Régis de
Published: October 2013

This paper presents the study of signal smoothing techniques, in order to select the best for use in a specific type of problem: determination of oxidative stability, by the computational calculation of the induction period. The oxidative stability is one of the major quality parameters of biofuels. According to some established hypotheses and metrics, the results of the study are presented, culminating in the identification of best available techniques related to each metric. This work also contains a case study presenting real use of the smoothing techniques in a signal collected by Ozomat (equipment for determining the oxidative stability).
Analysis on Aerodynamic Performance of Horizontal Axis Wind Turbine Based on Nonlinear Wake Model
Authors: Yang Rui , Wang Jiu Xin , Zhang Sheng Long
Published: October 2013

A computational method based on nonlinear wake model was established for horizontal axis wind turbines aerodynamic performance prediction. This method makes use of finite difference method to solve the integral differential equation of the model, the induced velocity of wake vortex can be calculated from equations and compared with the induced velocity of wake vortex in linear model. The comparison between the calculated results of wind turbine under axis flow condition, including tip vortex geometry and aerodynamic performance, and available experimental data shows that this method is suitable for wind turbine aerodynamic performance analysis. Finally, a series of numerical calculations were made to investigate the change of wake geometry and aerodynamic performance of the wind turbine when yawing and pitch angle increasing, which provide foundations for aerodynamic optimization design of horizontal axis wind turbines.
Research of the Nonlinear Wake Model of HAWT
Authors: Yang Rui , Zhang Sheng Long , Wang Jiu Xin
Published: October 2013

In the existing linear wake (cylindrical surface) model of horizontal axis wind turbines, the rotor was taken as the actuator-disc composed of infinite blades with infinitesimal chords. The distribution of variable circulation along blade was not taken into account and the span-wise (or radial) component of induced velocity is totally ignored. And assumed that the all trailing vortex filament shed from blade trailing edge would locate on their own cylindrical stream-surface. This aerodynamic model for determination of wake configuration is obviously different from that actually observed wake in wind tunnel experiment. Therefore, a "nonlinear" wake model was proposed, in this model the wake vortex system was divided into the central vortex along rotor axis, the bound vortex along blade axis, the wake vortex sheets shed from blade trailing edge and extent into infinity behind the rotor. Then, on the basis of potential theory in fluid mechanics a set of integral equations for evaluation of induced velocity in wake were derived with Biot-Savarts formula.
Preparation and Methylene Blue Adsorption Characteristics of Highly Mesoporous Rice Husk Active Carbon Prepared by an Alkali-Saving and Equipment-Friendly Method
Authors: Li Da Wei , Zhu Xi Feng
Published: October 2013

Highly mesoporous active carbon for removing methylene blue (MB) from aqueous solution was prepared from pyrolyzed rice husk by combination of CO2activation and NaOH-solution boiling. The preparation method was found to be alkali-saving and equipment-friendly. The prepared active carbon exhibited high mesoporosity (79.1%), with mesopore volume and specific surface area up to 0.619 mL/g and 899 m2/g, respectively. At initial MB concentrations of 240-380 mg/L, the MB removal efficiency of the prepared active carbon ranged from 92% to more than 99%, fairly comparable to that of the highly mesoporous commercial active carbon used for reference. The adsorption of MB onto the prepared active carbon well followed the pseudo second-order kinetic model and Langmuir isotherm. This study indicated that highly mesoporous active carbon with large dye removal efficiency could be prepared from rice husk by an alkali-saving and equipment-friendly process.
Short-Term Wind Power Forecasting Based on Least-Square Support Vector Machine (LSSVM)
Authors: Li Xiao , Wang Xin , Zheng Yi Hui , Li Li Xue , Zhou Li Dan , Sheng Xi Kui
Published: October 2013

In order to improve the rate and accuracy of wind power forecasting, the Least-Square Support Vector Machine method (LSSVM) is presented. LSSVM adopts equality constraints and defines the least-square system as the objective function, which can simplify the forecasting method to a large extent, as well as accelerate the rate of wind power forecasting. Through the analysis of the original load data, a reasonable choice on training set and test sample set is made in the simulation. Besides, many factors, such as, the temperature, wind direction, wind speed and power previous, are taken into consideration. The result shows that LSSVM is more effective than that of SVM.
Wind Power Prediction Based on Grey Theory and Simulation Study
Authors: Cai Zhong Hua , An Ting Ting , Zhang Hong Tu
Published: October 2013

Due to the significant instability, anti-peak-regulation and intermittency of wind power, wind power integration needs an accurate prediction technique to be a basis. At present, the difficulty of wind power integration has resulted in a large number of wind curtailment phenomena and wasted a lot of renewable energy. Grey prediction model has many advantages such as requiring little historical data and the simple model, with high prediction accuracy and convenient calculation, and without regard to regularities of distribution, etc. This paper puts forward the method for short-term wind power prediction using gray model GM (1, 1) and carries out simulation study and empirical analysis using the data from a wind farm of Jilin province, which shows the science and operability of the proposed model. It provides a new research method for the wind power prediction.
A Method and Analysis for Improving Thermal Efficiency of Nuclear Power Plant
Authors: Li Xian Ling , Liu Yang , Zhu Feng Jie , Yao Shi Wei
Published: October 2013

In order to improve thermal efficiency of nuclear power plant with a pressurized water reactor, this paper analyzed the reason why nuclear power plant runs with a low thermal efficiency, and then pointed out that the conventional operation mode results in a low thermal efficiency for middle and high load regions. A new method was proposed to improve its thermal efficiency by operating nuclear power plant under the condition with a high and constant steam parameter. Two problems encountered by the proposed method were investigated, and the results indicate that it is preferential way to increase flow rate of primary side coolant to boost steam parameter of the rated condition, and it is feasible to maintain steam parameter constant by regulating flow rate of primary side coolant continuously.
Pattern Classification for GIS Base on GK Clustering Algorithm
Authors: Wang Hui , Li Xiu Wei , Yun Yu Xin , Yuan Hai Yan
Published: October 2013

Four typical defects in GIS for PD detection are proposed, and the pulse, amplitude, phases, number of PD has been used to form the three-dimensional PQN matrix. Based on the PQN matrix, three two-dimensional distributions of Hqmax~Phi, Hqmean~Phi and Hn~Phi can be achieved. Then the new GK clustering method is introduced to separate the four different defects according to separate the four different partial discharge defects in gas in GIS, according to the parameters of Skewness (Sk), Kurtosis (Ku), number of peaks (Pe), cross-correlation factor (CC) and the discharge factor Q.
Harmonic Analyses of Power Grid in Large-Capacity Groups of AC-DC-AC Frequency Speed Drag System
Authors: Wang Ji Zhong , Tong Chao Nan , Li Rui
Published: October 2013

Based on the synchronous machine in AC-DC-AC Frequency speed drag System, a new power supply method of phase shifting combination is proposed by a detailed study of the impact in the power grid harmonics. With regard to the main Motor drive system of hot-rolling finishing mills, a large number of varying parameters quantitative analysis is made respectively for power load, LC filter, pulse-width modulation circuit and transformer, in which the grid side harmonic rate and waveform distortion rate is focused on. The simulation results show that the power supply method with reasonable parameters design of the drag system can be drastically reduce the grid side harmonic interference that the total harmonic distortion is suppressed within 4.0%. Results of this study provides an effective method for the design of the factory drag system, reactive power compensation system as well as fault diagnosis of electric drag system.
The Overview of Radioactive Waste Management Technology
Authors: Qiu Guo Hua
Published: October 2013

The Radioactive waste management technology is briefly introduced in this article based on related standards, guidelines and documents from IAEA. The radioactive waste management technology (RWM) includes related international standards and conventions, predisposal radioactive waste management, RWM for radioactive waste disposal, RWM for remediation, NORM and mining/milling waste. These management methods and valuable experience have important reference value to waste classification, waste disposal and management and related work in China.
Boundary Protection Strategy for the VSC-MTDC under DC Faults
Authors: Xu Yan , Shi Di Feng , Yan Shao Bo
Published: October 2013

Multi-terminal HVDC transmission system based on voltage source converter is a promising topology for the integration of the renewable energy sources. The fault characteristics of VSC-MTDC system under DC side faults was analyzed in this paper, as well as the particular requirements for the protection strategy. On the basis of the work metioned above, a four-terminal DC connected transmission system model was built in PSCAD/EMTDC. The boundary protection algorithm was proposed and the wavelet analysis was introduced. The protection scheme for VSC-MTDC transmission lines is based on the attenuation characteristics of line boundary for high frequency transient signals, which constitutes the operation criteria of the boundary protection. The protection scheme puts forward an effective method for the protection selectivity of the VSC-MTDC transmission system.
Mutual Capacitance Element
Authors: Zong Wei , Zhang Yu Shan
Published: October 2013

In order to realize the integration of electronic circuits and avoid the electromagnetic interference between mutual inductance components and periphery circuit, the paper put forward a new kind of coupling element-mutual capacitance components, which were dual with mutual inductance components, according to the duality principle and the gyrator application theory. First of all, the paper used the basic electrical components-operational amplifier, resistance and capacitor to set up the circuit implementation model of mutual capacitance component, and then selected device parameters to execute theory calculation. On the basis of the previous step, a simulation software-PSpice, was used to simulate the model. Finally, comparison of two different groups of simulation data showed the correctness of the circuit model and the feasibility of the mutual capacitance component.
Power-Frequency Electric Field Calculation of Ultra-High Voltage Substation
Authors: Cai Guo Wei , Wang Yi Gong , Han Dong , Song Wen Guo
Published: October 2013

To ensure the normal operation, calculation of electric field in ultra-high voltage substation is particularly important. A line model is proposed to simplify current model and improve computational efficiency. Combining this model with boundary element method, this article described a method to calculate the electric field at the vicinity of complex equipment of ultra-high voltage substation. An actual substation environment is also simulated, with detailed analysis of simulation results, proposed model and method are verified as valid and effective.
Design of Digital Single-Phase Full-Bridge Invert Controller Based on TMS320F28027
Authors: Ye Xiao Jian , Duan Zhen Gang , Shen Zhuo , Lian Xiao Qin , Zhang Xiao Li
Published: October 2013

This paper elaborates a method to realize the single phase full bridge inverter digital controller based on DSP TMS320F28027 and gives the design scheme of both its hardware and its software. In accordance with SPWM duty ratio parameter calculated with DSP algorithm, utilizing the EPWM module on DSP, it finally attains the inverting control from direct current signal to sine wave signal. Compared with traditional method, this new method improves the output waveform effectively and shows stable performance.
A Design Procedure for Electric Inductive Capacitive Resonators with Negative Permittivity
Authors: Zhou Shi Wei , Xie Yi Min , Li Qing , Huang Xiao Dong
Published: October 2013

Permittivity signifies a key component to metamaterial which can achieve negative index of refraction, but it has not been sufficiently addressed in computational design. This paper aims to attain negative permittivity through a topology optimization approach and provides an example equivalent to electric inductive-capacitive resonator. Similar to split ring resonator, this locally self-contained (without the demand for inter-cell connection) resonator allows keeping bulk electromagnetic properties homogeneously, facilitating mass fabrication, and realizing single sampling test.
Architecture and Key Technologies of Intelligent Dispatching Based on Situational Awareness
Authors: Yang Sheng Chun , Tang Bi Qiang , Yao Jian Guo , Li Feng , Yu Yi Jun , Feng Shu Hai
Published: October 2013

With the construction of UHV power grid, integration of large-scale renewable clean energy, and large-scale energy base putting into operation, the power grid dispatching faced with more and more complex challenges. On the basis of existing research results, architecture of intelligent dispatching based on situation awareness is proposed, so as to accurately achieve prevention and control of the power system. The shortcomings of traditional dispatching mode are analyzed firstly, and the concepts and characterization approaches of grid situational awareness and operation state trajectory of power grid are then introduced. The overall objective of intelligent dispatching is presented, including data processing and integrated knowledge mining, predictive perception of grid operation, risk analysis and comprehensive early warning, so as to achieve "automatic cruise under normal operating conditions, automatic navigation under abnormal operating conditions ". The functional framework of intelligent dispatching is also proposed in details, including four major aspects of the perception and forecasts, risk analysis, decision-making support, and automatic control, as well as three supporting functions such as post-assessment of dispatching, trajectory index calculation, and human-computer interaction (HCI).Technical innovations to support automatic intelligent dispatching are discussed and organised in three levels, i.e. perception, comprehension and projection. The breakthroughs are: construction of index system, trajectory recognition based on massive information and knowledge mining, trajectory projection taking into accounts the uncertainties, online risk assessment and early warning, power grid intelligent decision-making support, automatic coordination of grid operation control, online assessment, natural human-computer interaction mode, and etc... These are the future research areas of automatic intelligent dispatching.
Economic, Safe and Optimized Strategy of Operation of Transformer in Parallel Considering the Hot-Spot Temperature
Authors: He Zhi Min , Liu Ya Dong , Shen Wen , Sun Xu Ri , Wang Hong Jie , Sheng Ge Hao , Jiang Xiu Chen
Published: October 2013

In order to improve the economy of operation of transformer, this study presents a strategy to ensure the safety of power transformer for the situation of overload operation of parallel transformer. According to the variation of actual transformer operation, the authors divide the daily load curve into two typical time periods. In the high load operation period, except the constraint of minimum power loss for the economic operation, the factor for hot-spot temperature rise of the transformer should also be considered, so that an economic operation mode and parallel switching time could be obtained. This strategy estimates the hot spot temperature by the finite difference method, and obtains the optimal switching time through binary searching, according to the environment temperature and load curve. The analysis of the example of the operation of two sets of three winding transformers in parallel with different capacity shows that the method of optimization of the operation could reduce the loss. In the meantime, it could ensure the operation safety of the transformer, and prolong the service life of transformer.
Differential Evolution Algorithm Based Optimal Reactive Power Control for Voltage Stability Improvement
Authors: Immanuel D. Godwin , Kumar G.Selva , Rajan C.Christober Asir
Published: October 2013

Voltage stability assessment plays a major role in planning and operation of power system. This paper presents an efficient approach to solve reactive power control problem for voltage stability improvement. In this approach the voltage stability index is formulated to identify the most vulnerable bus at various operating conditions. The bus with the value of maximum VSI is considered as the most critical bus. To maintain the stability of the system the severity of the load buses has to be minimized. This can be achieved by the optimal settings of control variables using Differential Evolution Algorithm. The effectiveness of the proposed approach has been examined on the standard IEEE 30 bus test system under stressed and contingency condition.
Probability Analysis of Power System Cascading Failure Based on a Braching Process Model with Transmission Line Outage Data
Authors: Ren Hui , Xiong Ji , Chen Xi
Published: October 2013

Cascading failure has become the significant factor of the safe and reliable operation of grid with the development of power system. To assess the operation risk of cascading failure, we apply traditonal and improved branching process model to a a 14-year historical outage data from a regional power grid in China, computing probabilities of cascading line outages. Then the probability distribution obtained from the 2 moedls are compared by fitness test. As the simulation result shows, for the historical data, the empirical distribution of the total number of line outages is well approximated by the improved branching process model with propagation parameters and initial outages. The fitness test provide quantitative evidence that the improved model fits the data better than the conventional model.
Time-Varying Characteristic Based Load Forecasting Method for Distribution Network with DGs
Authors: Zhao Ming Xin , Li Yang , Chen Hai , Liu Wei , Zhang Pan
Published: October 2013

Middle-term and long-term load forecasting is important for planning of distribution network. With DG (distributed generation) integrated into network, the net load demand of HV/MV transformers become more complicated, load forecasting encounters greater challenge than ever. Uncertainty of wind and solar power has greatly influenced the load characteristics. A new load forecasting method for distribution network with DGs is proposed in this paper, which concerns time-varying characteristic of DG output power. Firstly, we get the conventional spatial load forecasting results. Then, using Monte Carlo simulation, we get the time-varying characteristic of DG. Lastly, superposing time-varying characteristics of conventional load and DGs, we can get the net-load forecasting result for distribution network.
A Sensitivity Analysis Method for Transient Stability Assessment Feature Selection
Authors: Yao De Quan , Zhao Shuai , Jia Hong Jie , Liang Hao
Published: October 2013

Input features selection is the premise of transient stability assessment base on neural network method. This paper adopts sensitivity analysis method to calculate the sensitivity-matrix of input features. And on this basis it defines important indexes and impact factors. Based on the gap information of impact factors, it selects the optimal subset of input features, which helps to decrease the redundant information and reduce the dimension of input features. This approach can improve the efficiency and accuracy of transient stability assessment effectively. The results of New England test system demonstrate the validity of the approach.
Capacity Limit of Grid-Connected Wind/Photovoltaic Hybrid Power System Based on Interior Point Algorithm
Authors: Li Nan , Zhu Shou Zhen , Zheng Jing Hong , Bai Xiao Min
Published: October 2013

Wind/Photovoltaic hybrid generating system can alleviate power fluctuations caused by the single source and improve the system power supply reliability. In the stage of planning, the grid-connected scheme and capacity limit calculation problem is needed to solve. Under different schemes, the capacity limit is different. This paper established an optimization model of capacity limit of wind/photovoltaic power station, introduced the tracking center trajectory interior point algorithm to solve capacity limit, and demonstrated the validity of the proposed method by a simulation of IEEE 30-node system considering the reserve capacity, and concluded that capacity limit is larger when Wind/Photovoltaic is parallel in heavy load nodes. This method can provide reference for practical system of calculating capacity limit of wind farm or photovoltaic power station and is feasible.