Search

In this paper, the finite element model of river ice collision on the pier was established by adopting explicit dynamic analysis software package, LS-DYNA. And the finite element analysis model establishment methods for calculating the collision interaction forces between the river ice and flexible high pier were studied. The simplified constitutive model of river ice was proposed. Factors influencing the simulation of flow ice collision on piers were discussed including the meshing size of ice sheet, and the meshing size of pier in contact area, the contact type with related algorithms. The study show that Solid164 can be used to simulate the ice sheet and the contact area of pier; in terms of the model of collision effect between river ice and flexible high pier; automaticsurface-to-surface contact type, ASTS, is the most appropriate; the river ice can be simplified as linear elastic material; rigid body can be used to connect the solid element and beam element. The conclusions drawn from this paper provide a new method for calculating the collision force between ice sheet and flexible high pier, which has a significant meaning in calculating the river ice collision forces theory.

This paper describes how to detect energy consumption automatically, especially based on infrared images. We find a method of combining those pictures efficiently. In order to make a direct conclusion, we make a bar of temperature distribution.

Thermodynamic equilibrium is proposed to analyze the distribution of SO3 in different flue gas circulation modes to study the migration law of sulfur for oxy-fuel combustion. Results indicate that the concentration of SO2 increases dramatically when flue gas circulation is adopted with the decline of flue gas volume and the increase of oxygen concentration in oxy-fuel combustion, which results the increase of SO3 concentration and formation rate. At 1200°C, thermodynamic equilibrium concentration of SO2 and SO3 are 5.3 times and 6.1 times respectively compared with conventional combustion. In Oxy1 circulation mode, SO3 is the most sensitive to excess air coefficient and sulfur content, followed by Oxy2 circulation mode, while the conventional combustion has the lowest sensitivity. Therefore, SO3 is greatly influenced by different flue gas circulation modes during oxy-fuel combustion.

The precision agriculture (PA) is the end product of the modern high tech's information technology and the agricultural production technology union. The soil nutrients are not only an important component of soil research, but also a critical determinant of its productivity. Some soil nutrients spatial distribution pictures were established based on important factors that affect crops production. The soil nutrient situation was understood by the paper in Jilin province black soil. The results can realized some information opening and sharing and helped some farmer and manager to understand some soil nutrient spatial distribution. They can speed up the development of Jilin province’s precision agriculture.

Aiming at the problems of travel time tomography with sparse rays, this paper improves the inversion stability by optimizing experiment design. This paper analyzes the influence factors of inversion stability and proposes the evaluating function on optimizing experiment design. The numerical simulations show that the optimization method is feasible and the optimum design make inversion more stable.

A data communication method applicable to building detection industry based on the wireless sensor network (WSN) is designed and implemented in this paper, in which the cause of data loss is analyzed in accordance with the characteristics of wireless sensor network and that of building detection industry. Besides, relevant data storage protocol, staggered transmission protocol, and real-time data replenish protocol are formulated to solve the problem above and improve the reliability and integrity of data.

In view of the question that the inlet boundary conditions of turbulence information for the large eddy simulation process is difficult to be settled, the target wind field was divided into blocks along the height direction firstly. Under the assumption of the same height and its nearby area, fluctuating wind field characteristics are the same, the one-to-one relationship between time-history data and the target area was established, using the classical WAWS to simulate the fluctuating time-history data of wind field. Then the time-history data were given to the homologous grid of the target wind field during the process of large eddy simulation, and fluctuating information of the large eddy simulation in the whole entrance was obtained consequently. Finally, a secondary development of the commercial software FLUENT was proceeding, and a simulation of the flow field without any obstacles was established. The fluctuating time-history data were written in by using the method presented in this thesis, and the entrance boundary conditions were generated. By analyzing the wind field’s power spectrum and correlation at different positions, we find that the wind field generated by the method presented in the paper can satisfy the basic characteristic of the fluctuating wind field, and it also provides references for the refine research of the large eddy simulation boundary conditions.

The sensor nodes in WSN are generally limited in energy, and the communication between nodes consumes most power. Therefore, it is the key point to reduce energy consumption and network traffic when designing routing protocols for WSN. The Low Energy Adaptive Clustering Hierarchy (LEACH) protocol is a widely used and studied WSN routing protocol. In this paper, an improved LEACH based on energy-consumption optimization (LEACH-EO) was proposed against the deficiencies of LEACH. LEACH-EO implemented some improvements on the cluster-head selection of LEACH, meanwhile, the data redundancy of WSN was exploited to optimize the data transmission according to the characteristics of WSN. The simulation results show that LEACH-EO increases network lifetime and reduces energy consumption in comparison to LEACH.

Currently, researches on time constraints for access control are not complete. To solve this problem, this paper enriches the time constraints for access control from the following aspects: firstly, we propose a four-tuple representation of time constraint by combining discrete time representation and periodic time representation; secondly, we put forward a function of computing the time of state changing on the basis of (1); finally, aiming at conflicts detecting and resolution for time constraints, we raise an algorithm for conflicts detection and resolution based on XACML and entities overlapping detection.

In this paper, the theory of the fuzzy control and self-learning ability of neural network is combined, joining the genetic algorithm to optimize the fuzzy control rules, so in the light of temperature control system of variable air volume air conditioning puts forward a fuzzy neural network control method based on genetic algorithm,and this paper introduces in detail the structure, algorithm of fuzzy control and neural network. In addition,this paper verifies the superiority of the fuzzy neural network based on genetic algorithm and ordinary fuzzy neural control.

Oxidized alkaline loofah sponge (OAL) was given by treating alkaline loofah sponge (AL) with H2O2, four classic adsorption kinetics models which were Lagergren’s pseudo-first-order, Pseudo-second-order equation, the Elovich equation and Intraparticle diffusion were applied to study how the different oxidation degrees of loofah sponge impacted on the values of fitting goodness of the above models and to determine which kind of model was the best fit of the adsorption process and adsorption mechanism. The results showed that Pseudo-second-order equation’s fitting degree was proposed to be best and adsorption mechanism was chemical adsorption by ionic bonding, at the same time, as hydrogen bonds increased, water molecules formed a barrier to impede MB diffusing into the micro-structure.

This paper analyzed the effects of the off-farm employment and the outsourcing production pattern on the technical efficiency of grain production by the two-step method of DEA-Tobit, based on the data of grain production in the major areas of Liaoning province, in the year of 2011. It observed these findings that off-farm employment and income structure change did not have an effect on technical efficiency. Even then this is evidence that age makes a negative effect on farm technical efficiency but it is weakly. Farm scale and specialization have a positive effect on technical efficiency. And both large farm and small farms scale efficiency is on a high level. So a limited impact on farm technical efficiency comes from farm scale as well as a significant positive impact comes from farms production outsourcing.

Radio telemetry is used as a major way on monitoring flight test of airplanes. As information transition channel is disturbed or interrupted significantly during the blackout area during flight, the carrier information will not be transmitted normally. However, the airplane data during the blackout period has to be monitored seriously. This issue can be resolved by building re-issued data memory function into a telemetry system. This paper looks at the research of re-issued data memory technology and proposes a new design of re-issued data memory circuit for realizing the negative trigger delay storage of data flow in telemetry system during blackout period. The delayed data in the storage will be transmitted again later. The new designed circuit uses multiple re-issued data memory methods to satisfy the requirements of different telemetry tests and measurements, assuring complete data during airplane flight test.

This paper focuses on the home-country factors determining the rapid growth of China's ODI and provides empirical evidence based on 66 countries panel data over 1991 to 2010. First, we expand the investment development path (IDP) theory by including financial factors to establish benchmark model. Then, we explore whether China's net ODI flow is excessive or insufficient by adding China dummy. Finally, we examine the special factors driving and hindering China's ODI by introducing interaction terms. The results reveal that China's ODI level is insufficient. The economic development, export and international reserve drive the growth of China's ODI, while crowing-out effect of domestic investment and poor financing condition are obstacles.

The third-party damage is the main factor of Daqing-Harbin oil pipeline failure. This paper analyzes a variety of factors causing the third-party damage, and establishes the fault tree model. By analyzing the minimal cut set and structures importance degree of fault tree, the main factors of the third-party damage that caused pipeline failure are determined. The main factors are as follows: Lack of pipeline conditions, human vandalism, the frequency of line patrol and management systems, lack of public education and the legal concept, and construction operation injury. On the basis of analyzing the factors, the precautions of the third-party interference are proposed.

Euler beam dynamic analysis model under moving loads and wheels plus spring-damper-sprung mass action were established respectively. The simply-supported beam motion control equations were derived and the corresponding simulation analysis procedures were worked out. The vertical dynamic responses of simply-supported bridge under typical vehicles at different speeds were studied systematically. Impact factors calculated from the two analysis model were compared with the values of the current bridge specifications. It is shown that vehicle inertia force has little effect on the vertical deflection and vertical vibration acceleration of the bridge, the vehicle impact effect on bridge gradually go up with the passing speed increasing, vehicle weight has great influence on the vertical vibration of the bridge. The problem of passing overloaded vehicles must be considered seriously in bridge design and use.

In masonry structure transformation, due to the removal of walls, force transmission path and force structure mechanism of load-bearing walls will be changed. So it become greatly important to adopt a safe, applicable, economic and reasonable underpinning method. This paper introduces several underpinning methods of masonry structure modification, which summarizes the advantages and disadvantages of them. Their characteristics and using condition are discusses in the paper. Some conclusions which are drawn may be referenced for the future engineering practice.

A class of backward stochastic differential equations are studied. We obtain the comparison theorem of these backward stochastic differential equations under non-Lipschitz coefficient.

Target localization technology has been intensively studied and broadly applied in many fields. This paper presents one improved particle swarm optimization technique in training a back-propagation neural network for position estimation in target localization. The proposed scheme combines particle swarm optimization (PSO), back-propagation neural network (BP), adaptive inertia weight and hybrid mutation, called IPSO-BP. To verify the proposed IPSO-BP approach, comparisons between the PSO-based BP approach (PSO-BP) and general back-propagation neural network (BP) are made. The computational results show that the proposed IPSO-BP approach exhibits much better performance in the training process and better prediction ability in the validation process than those using the other two base line approaches.

This paper gives a method to calculate the temperature rise of the water cooled PM railway traction motor using 3D fluent and thermal field. Building a 3D Finite Element Method (FEM) model of 20kW PM synchronous traction motor, the heat transfer coefficient of each tunnel wall is calculated by fluent field, and then the temperature distribution is got from thermal field. Compared with the experimentation, the precision of this method is verified and some conclusions are obtained.

Quantum-behaved particle swarm optimization algorithm (QPSO) was proposed as a kind of swarm intelligence, which outperformed standard particle swarm optimization algorithm (PSO) in search ability. This paper presents an improved QPSO with nonlinear controlled parameter according to the fitness value of the particles. Simultaneously, we apply the improved QPSO to solve the problems of target position measurement. The experimental results show that the improved QPSO has faster convergence speed, higher measurement accuracy, and good localization performance.

This paper introduces the omnidirectional vibration sensor based on MEMS three accelerometer, which is used to solve the problem that the tradition vibration sensor cannot acquire multidimensional vibration signal effectively, on the background of underground distributed passive localization.It has MEMS accelerometer as the core detection unit, including three dimensional vibration detection unit, signal conditioning unit and power supply unit. It adopts the spherical shape ,which consists of Aluminum shell、Potting material of Epoxy resin and Multilayer circuit board. By means of finite element analysis and Field test, it shows that this sensor can effectively get omnidirectional vibration signal vector information, and the engineering application value is great.

This paper analyzes structural features of the prolog compiler on the basis of its executive mechanism. The main focus of the research targets the functional characteristics and the working mechanism of the compiler through the analysis of prolog language organizing and translating procedure in conjunction with the logic-reasoning attribute of the language. The paper illustrates structure of three important modules and demonstrates their corresponding realization method. The research of lexical compiler will lay a foundation for future works of upgrading and developing Prolog compiler.

The stiffness of reinforced concrete simple beams strengthened with carbon fiber sheets is studied in this paper. The calculation formulas of it are discussed, for steel yielding and not yielding. The stiffness increases with the number of carbon fiber layer or reinforcement ratio increases.

To calculate difference scheme’s accuracy of differential equation, the normal way is using Taylor format. This paper utilizes tectonic process of differential format to calculate truncation error and gets the accuracy. Compared with the traditional way, not only reduces the amount of calculation, but also calculates the accuracy more quickly and accurately for high-order equations.

Ground gathering pipelines in a high flow-rate gas condensate field were seriously corroded and became perforation only after five months operation. The results of witnessed inspections and analysis showed that T-branch pipe, Elbow and weld were corroded most seriously. The main features of the corrosion were trench-like corrosion pits. In order to clarify the reasons for corrosion so seriously, XRD, SEM, EDS were used to test the film of sample which was taken from the field. The results showed that wall thinning of pipelines was mainly caused by CO2 corrosion combined with erosion and the corrosion product was mainly composed of FeCO3.

In this paper, a new method is presented to optimize the elevator traffic system based on queue model. The application of this method is studied in detail. Parameters for the elevator running including number of elevator passenger, average waiting time and arriving ratio, and the relationships between them have been analyzed as well. Therefore, the dispatching of elevator dynamic partition can be done. The actual data of rush hours are used for simulation tests. The simulation results show that this method has good performance. The method is a more practical control strategy especially in rush hours.

In order to analyze the uncertainty existing in the stability of slope with geocell, the fuzziness of soil property parameters should be considered. In this paper, probability density function of structural performance function and membership function of the stability of slope with geocell was determined. The fuzzy reliability model of the stability of slope with geocell was established. The fuzzy reliability and fuzzy failure probability of slope with geocell instability were calculated, and the practicability of the calculated model was verified.

A class of backward doubly stochastic differential equations are studied. We obtain a comparison theorem of these multi-dimensional backward doubly stochastic differential equations.

Traditional road green growing material does not take into account the particularity of green traffic areas. Characteristic of the road greening and ordinary green standard is not the same. In road greening projects, vegetation planting layer is required to meet the basic conditions for plant growth, in addition vegetation planted layer need structural requirements. Fired brick and tile waste material have microporous structure. The pore structure is capable of storing water and nutrients, fired brick and tile waste materials have the stronger crushing strength and frost resistance. Fired brick and tile waste can satisfy the dual needs of the structure and plant growth. These characteristics determine fired brick and tile waste to have enormous potential in the road greening projects.

This paper introduces vibration analysis, state monitoring, faults diagnosis, system compose, test scheme and measure point disposal of air compressor. This uses CDMS to do．Analyzing the mechanics vibration parameters in time domain and frequency chart in frequency domain. According to the results of information dispose finding out faults reasons and position，educing diagnosis conclusion, the motor-side bearings 3628 has more serious pitting and peeling off, recommended replacement，the horizontal chute and vertical chute of the air compressor has wear, exists insufficient lubrication. Lubrication management and monitoring should be strengthened.

The analysis, modeling and simulation of the avionics system is the flexible and effective method to evaluate and study avionics system with IMA architecture. With Queueing Theory, we summarize the stability condition, analyze and approximate the end-to-end delay in FC tandem network. In the OPNET, we simulate FC tandem network by building periphery node model, switch node model and the queue process model. Simulation result shows that, under the stability condition, the number of periphery nodes, or the rate of sending data packets has almost linear relationship to end-to-end delay, as the number of switches does nonlinear one.

The genus of Crataegus (hawthorn) is cultivated in many parts of the world. and regarded as medicinal plant in many countries. Hawthorn fruit is commonly used to cure scurvy, constipation and digestive disorders, Hawthorn flowers and leaves are often used against mild cardiac disorders. Modern studies found extracts of Hawthorn fruits, flowers and leaves possess a wide range of pharmacological properties, the pharmacological properties of Hawthorn are mostly related to the involved phenolic compounds including flavonoids. In this article, the active chemical properties and medicinal value of Hawthorn are reviewed.

Objectives To analyze CPn0308 immunogenicity in the CPn infected patients with ICVD. Methods ①Clinical blood samples and separate plasma from blood and extract the DNA from PBMC were collected. ②The CPn IgG and CPn IgM were detected by using CPn specified diagnose kit. ③CPn DNA from PBMC was assayed by using PCR.④Imunogenicity of the endogenous CPn0308 was analyzed by Western Blotting. Results①Among the 70 patients with ICVD, the positive rate of CPn IgG was 51.43%, and it was higher than that of control; The positive rate of CPn IgM was 2.86%, and that of control was 8.47%. ②The positive rate of CPn DNA in PBMC from patients with ICVD was 81.08%，and it was higher than that of control. ③After plasma samples were diluted as 1:500, the antibodies to endogenous CPn0308 were still detected by using Western Blotting. The reaction was blocked after the plasma was pre-absorbed with GST-CPn0308 beads ahead, but not pre-absorbed with GST-CPn0186 beads. Conclusion ①There is an increase in the positive rate of CPn IgG in the patients with ICVD. ②The positive rate of CPn DNA in PBMC from the patients with ICVD is higher than that of the control. The positive rate for CPn by PCR is higher than that of EIA, and CPn DNA detection is a more sensitive method. ③The studies preliminarily demonstrate that CPn0308 has immunogenicity in the individual infected with CPn.

Geocell protection of slope was influenced by environment and climates largely. Many of them came to failure when subjected to rainfall infiltration. Aiming at the general shear failure mode of the geocell-protection-system (GPS), its stability analysis model during rainfall was established by the limit equilibrium method. A new approach of evaluating stability of the GPS was proposed.

“Farmer-supermarket direct-purchase” is a new mode of circulation for agricultural products in China. Without a modern logistics system, it cannot be taken into practice effectively. In view of the present situation of fresh agricultural products logistics, some problems exist: lack of effective logistics information platform, poor logistics technology and high logistics cost. Some measures should be taken by the government and supermarkets and farmers’ co-operatives to improve the development of fresh farm product logistics.

As a quasi-public traffic mode, more and more attention has been paid to the commuter bus to ease the traffic congestion. To get the travel behaviors of the commuters to which the commuter bus is available, The RP and SP survey about the travel behavior of commuters were carried out and the influencing factors of mode choice are discussed. The commuting mode combinations were found to exist during the decision-making process and there exist the preferred mode and secondary mode for each individual for one trip mode choice. The preferred mode choice model is established based on the multinomial logit mode. The results show that gender, month income, vehicle ownership, commuter cost, and commuter time have marked influences on the result of preferred mode choice for commuter purpose. The goodness of fit parameter ρ2 and goodness-of fit index adjusted by freedom ρ2 of the preferred mode choice model are 0.407 and 0.369 respectively, which implies that the forecast accuracy of the model is high. The VOT of the respondents in the survey is 29.9RMB/h and the results can provide a good reference for designing and optimizing of the commuter bus.

The preparation of Ni-doping alumina foams as precursors for MMCs (Metal Matrix Composites) fabrication was studied. Alumina foams were successfully adulterated with Ni using organic foam impregnation technique. Uniform Ni particles were distributed in alumina struts after they were sintered in a vacuum furnace. At the crucial infiltration step, an inducer such as elemental Ni melted so that interpenetrating channels were created in the ceramics. In contact with Fe melt, the metal matrix could spontaneously infiltrate in alumina foams struts. The influence of infiltration was subsequently investigated by SEM and EDS. Preliminary results showed that the interface between Ni-doping alumina foams and Fe metal matrix reached a full structural homogeneity and the use of Ni-doping alumina foams enhanced the capability of infiltration when processing continuous three-dimensional interconnected ceramics/metal networks MMCs by pressureless infiltration technique.

Metal matrix composites (MMCs) were produced by Ni-induced pressureless infiltration using Fe alloy. The mainly fabrication process was that Ni and Al2O3 powders mixture was pressed and sintered after milled, and then the sintered Al2O3 ceramics were infiltrated by Fe alloy at 1600°C with 4h holding time. While the SEM and EPMA analyses indicated that the interface between ceramics and Fe alloy reaches a full homogeneity after infiltration and Fe alloy could infiltrate Al2O3 ceramic preforms and the maximum infiltration distance was more than 400 μm. This would increase the strength of interfacial due to excellent bonding interface. The fracture strength is about 63.0 MPa.

A novel frequency shift keying (FSK) receiver is presented, including receiving antennas, a low noise amplifier (LNA), band-pass filters (BPF) and a novel all-digital 2-level FSK demodulator. The Matlab simulation results of the all-digital FSK demodulator show that it can improve bit error ratio (BER) performance compared with pseudo-coherent FSK demodulation (PCFSK). The novel FSK demodulator defined using Verilog HDL is easy to be implemented on Field Programmable Gate Array (FPGA) and in CMOS integrated circuit. The whole FSK receiver designed and implemented on a PCB board can receive FSK signal and send the recovered data to computer through RS-232 interface.