Search

According to exist technical problems and requirements of the air-suction peanut precision mulching film and punching planter, the new air-suction peanut precision dibbler of the planter’ key working part was researched. It was introduced the composition and working principle of the dibbler. According to functional and technical requirements of the dibbler’ main parts, the structural design and analyze were done. The dibbler mainly consists of roller body, cavitations’ components, transmission system, and the air suction metering device. In the peanut growing typical region, field trial of the dibbler showed that overall performance is relatively stable, each component are operating smoothly, and the operating indicators can better meet the technical requirements.

Distributed combined cooling, heating and power (CCHP) system shows great advantages and provides new development space for energy construction of rural areas in China. Economic benefits are the most important factors determining the further development of distributed CCHP system in rural area and the operation strategies make a great impact on its economic benefits. This paper establishes an analysis model for the operation strategies following the thermal loads (FTL) of NG distributed CCHP system driven by gas-steam combined cycle. The prime mover used in this investigation is a gas-steam combined cycle based on combined gas turbines and steam turbines. The model presented in this paper can be used to determine the operation strategies of CCHP system under different daily periods: peak periods, flat periods, and valley periods in different seasons.

Purpose: The aim of this study is to contrast the coupling algorithm (CEE) and boundary heat exchange coefficients (Nu) used in treatment of the large blood vessel in thermal ablation. Methods: Based on the Pennes bioheat transfer equation, the models with blood vessel parallel to microwave antenna were built with finite element method. In two kind of simulation, blood flow rate was set in 0.2 m/s or boundary heat exchange coefficients was set in 1750 W / (m2 °C), respectively. Results and conclusions : There was no significant difference on shape of effective ablation areas and 54°C temperature contours by using two kinds of simulation methods, especially the place far away from the blood vessel. At the place near the blood vessel, the method of CEE is closer to real condition which considers directivity of blood. Whats more, there are higher temperature by using method of Nu inside effective ablation areas.

Continuous wave (CW) radar and global positioning system (GPS) is the main equipment of trajectory measurement in range. Based on range test background, propose a method to fuse GPS pseudo-range and CW radar range to provide complete trajectory positioning parameters, effectively reduce the impact of the systematic error of the measuring element to improve positioning precision of aircraft orbit solving. Through research on the measurement principle and the practice calculated data is given in this paper. Finally, several famous practical examples and simulation results are presented to illustrate our method efficiently.

China is experiencing a large scale of building construction, attracting great attention paid to debris generated by frequent construction and demolition activities for its cost inefficiency and environmental pollution. It is of great importance to better understand the magnitude and composition of the waste stream when developing rules, policies and strategies to manage this segment of the solid waste. In this study, after clarifying the definition of construction and demolition (C&D) waste according to its complex composition and diverse sources, approaches quantifying C&D waste to meet different requirements were summarized, and a simple weight-per-construction-area was employed to make an approximate estimation. Based on the main causes and status quo of C&D waste management, measures to reduce C&D waste were proposed to realize a sustainable construction industry, which include improving environmental awareness, strengthening the establishment of policy system and company waste management system, and reinforcing research and study work. This study also adds to the knowledge on research trend of C&D waste in China.

Sinter is the main raw material for ironmaking. It is very important to control sinter chemical composition and comprehensive performance. In this paper, a predictive system for sinter chemical composition FeO and the sinter yield was established based on BP neural network, which was trained by actual production data. The MATLAB m file editor was used to write code directly in this paper.The application results show that the prediction system has high accuracy rate, stability and reliability, the sintering productivity was improved effectively.

Tiered pricing of household electricity is a new price measure using economic leverage to encourage energy conservation and emission reduction in electric power industry. Based on demand side response theory, the coal-saving optimization model of tiered pricing was established and the coal-saving effect under different structure of coal-fired units was studied. The results of case study indicate that the economic leverage role of tiered pricing will promote the clean energy power generation connecting to the grid effectively, and the coal-saving effect of tiered pricing in the areas with high comprehensive coal consumption rate of power generation will be more remarkable.

The sinter quality and the stability of composition could directly affect the yield, quality and energy consumption of ironmaking production. It is important for iron and steel industry to steadily control sinter chemical composition and analyze sintering energy consumption. The MATLAB m file editor was used to write code directly in this paper. A predictive system for two important sinter chemical composition (TFe and FeO), sinter output and sintering solid fuel consumption of was established based on BP neural network, which was trained by actual production data.) The application results show that the prediction system has high accuracy rate, stability and reliability, the sintering productivity was improved effectively.

For a long time, there is serious cross-subsidization among the power sales prices in China, and tiered pricing of household electricity is a new price measure for power consumption equity, resources utilization rationality and then achieving resources conservation and environmental protection. Based on demand side response theory, the optimization model of tiered pricing of household electricity with objective function of minimum household electricity consumption was built, and the coal-saving effect of tiered pricing was studied. The results of case study indicate that energy and coal saving effect of tiered pricing is remarkable.

Through analyzing the design methods of liquid sliding bearing and the matching spindle of common roller grinding head, the design methods and ideas of liquid sliding bearing and the matching spindle of high-speed roller grinding head are put forward, and on these bases, a kind of liquid sliding bearing and the matching spindle of high-speed roller grinding head are designed. By means of finite element analysis of the bearing and the matching spindle respectively, it can be known that thermal property of the designed liquid sliding bearing can meet the working demands of high-speed roller grinding, and the designed spindle can meet the demands of strength and stiffness under the condition of high-speed grinding, thus, important reference materials for forming core technologies of high-speed roller grinding head are provided.

Topsoil porosity (TSP) is an important parameter for the research of soil physics, agriculture and environmental protection. However, the traditional method for measuring porosity is time consuming. Conversely, a series of new methods measuring soil surface roughness (SSR) are increased and become more and more quickly. Some researchers propose to predict TSP by SSR. In this study, two fields cultivated by different tillage type were investigated under natural condition during four years (2006-2009). The results of this study show that (i) both of soil roughness and porosity are decreased over time; (ii) there are strong correlation between soil porosity and roughness effected by rainfall; (iii) after introduce the index of accumulative mean rainfall (AMR), a model of multiple linear regression for presenting the correlation among SSR, TSP and rainfall was built using sampling data of 2006-2009 with R2>0.7.

Model for predicting wood density of Larch was established using near-infrared spectroscopy (NIR) combined with support vector machine (SVM). A hundred and seventeen Larch samples were used in the study. Wood density of samples was measured according to standard test methods for physical and mechanical properties of wood. Support vector machines for regression (SVR) was used for model building. Radial basis function (RBF) was used as kernel function to establish a model for predicting wood density. For the train set, the coefficient of determination (R2) and the mean square error (MSE) were 0.8504 and 0.6460×10-3, while the R2 and MSE was 0.8520 and 0.4451×10-3, respectively, for the test set. Results showed that using SVM in near-infrared spectroscopy calibration could significantly improve the model performance in order to rapidly and accurately predict wood density.

Water content of Korean pine samples was studied using near infrared spectrascopy (NIR) combinded with parial least squares regression (PLS) analysis. Seven typical wave lengths were selceted to characterize the wood water content of Korean pine. Prediction models of wood water content were developed based on the original NIR spectra at seven varied wave lengths. The best model was showed between wavelengths from 1000 to 2100 nm with correlation coefficient (R) of 0.9871, standard error of calibration (SEC) and root mean square error of calibration (RMSEC) of 0.0337 and 0.0334, respectively. The correlation coefficient（R） for model validation was 0.9817 with standard error of prediction (SEP) and root mean square error of prediction (RMSEP) of 0.0470 and 0.0465, respectively. This study indicated that NIR is a useful tool for fast prediction of wood water content of Korean pine. The modeling proficiency could be improved significantly for some certain wave length. It could be a research focus for future related studies.

The paper introduces a new method for prediction of electromagnetic compatibility in the power system, and use the Electromagnetic simulation software ATP. By comparing the actual test results to the simulation results, it is proved that electromagnetic transient simulation is reliable and effective. It also introduces the Gray prediction theory to predict the next Electromagnetic Interference (EMI) of the substation. It is high practical to research and analyze the substation electromagnetic compatibility, and feasible to use the Gray prediction theory with multivariable for the model EMI prediction analysis.

Application of BP neural network and NIRS for larch wood density prediction was investigated in this paper. The original spectra were collected and pretreated with the first derivative and 9 point smoothing. Eleven typical wave lengths were selected as BP network inputs to establish prediction model for wood density. Model was validated using cross-validation approach. The prediction correlation coefficient (R) is 0.916 while the root mean square error of prediction (RMSEP) is 0.0221. The results showed that using BP neural network in near-infrared spectroscopy calibration could significantly improve the model performance in order to rapidly and accurately predict wood density.