A more accurate analysis method on working modes is proposed by considering the winding terminal voltage and the eondueting power device as state parameters. For the three-phase hybrid excitation doubly salient machi...A more accurate analysis method on working modes is proposed by considering the winding terminal voltage and the eondueting power device as state parameters. For the three-phase hybrid excitation doubly salient machine （HEDSM） motor and its three-phase full-bridge inverter, in the proposed analytical method, all possible working modes are generally listed. Then, with the H_PWM-L_ON control strategy, the working modes are detailed with eorresponding equivalent circuits. Experimental results verify the robustness of the analysis.展开更多
A new type of linear ultrasonic motor with two degrees of freedom (DOF) motion is presented. The concept of the new typical motor is based on the combination of a longitudinal and two bending modes. The construction a...A new type of linear ultrasonic motor with two degrees of freedom (DOF) motion is presented. The concept of the new typical motor is based on the combination of a longitudinal and two bending modes. The construction and the operational principle of motor are described, and the elliptical motion of the driving point of the actuator is proved. Meanwhile, a prototype linear motor is designed by using the finite element method (FEM) and is constructed for experiments. The vibration modes are tested with the laser doppler vibrometer (PSV-300F), and the experimental results prove that the design requirements on the mode shape of the actuator and nature frequency are satisfied. The test run of the motor indicates that the operational principle of the motor and the design results are correct, and the output properties are also tested.展开更多
To solve the problems of mechanical cam, tracking in an automatic welding machine, a new method of programmable logic controller ( PLC) tracking is presented. Based on analyzing the forming of welding tracking, a math...To solve the problems of mechanical cam, tracking in an automatic welding machine, a new method of programmable logic controller ( PLC) tracking is presented. Based on analyzing the forming of welding tracking, a mathematical model of position control is set up. The experiments show that using a modified machine, PLC makes little welding positional error and can meet the product requirements.展开更多
This paper proposes a new type of pulse launcher that applies the principle of linear motors. The stator, viz. gun barrel, of the launcher has a new structure of one segment of iron core consisting of 3 staggered lami...This paper proposes a new type of pulse launcher that applies the principle of linear motors. The stator, viz. gun barrel, of the launcher has a new structure of one segment of iron core consisting of 3 staggered laminations. This structure is helpful in advancing the thrust force per volume. Based on introducing the structure and the working principles, this paper resolves the electromagnetic thrusting force and performs mechanical analysis and experiments on the sample launcher. The research shows that this launcher is simple and brushless structure with brief controlling.展开更多
Currently, the monitoring of bridges in China heavily relies on manual operation, which has several major problems. It generally takes a very long time to complete an inspection process on bridges. The manual data is ...Currently, the monitoring of bridges in China heavily relies on manual operation, which has several major problems. It generally takes a very long time to complete an inspection process on bridges. The manual data is sometimes unreliable or even wrong in the case of careless operation. The inspection activity itself is dangerous for inspectors, e.g., bridges are located in the sea or river. Some semi-automatic monitoring methods are recently employed, but they are either very expensive or do not work properly. Therefore, the traditional bridge monitoring process becomes an increasing challenge for bridge operators. In this paper, a real-time and automatic bridge monitoring system is presented to meet the bridge monitoring needs, and MEMS （Micro Electro Mechanical Systems） are the key building block in this system. By using the MEMS-based sensors, it is much more efficient and accurate in monitoring bridges with the measurement of inclination, acceleration, displacement, moisture, temperature, stress and other data.展开更多
A new method for determining the incremental cohesion △Cm of surrounding rock due to prestressed cable anchor is presented, and the formulas for △Cm are deduced and △Cm distributions also are discussed, based on th...A new method for determining the incremental cohesion △Cm of surrounding rock due to prestressed cable anchor is presented, and the formulas for △Cm are deduced and △Cm distributions also are discussed, based on the two anchorage effects, one is the effect with the prestressed vaIue △σ3 of cable anchor improving the stress state of surrounding rock and increasing the surrounding rock strength, the other is the fully encapsulated effect. The determined incremental cohesion △Cm is subiected to the model test and field measurement in the references, and coincides well with those tested results. The formulas for △Cm can be used in designing supoport parameters and related numerical analyses of prestressed cable anchor.展开更多
In this paper, a simulation model of Permanent Magnet Linear Synchronous Motor (PMLSM) is established by using phase equations method. Special attention is paid to its structure and the influence of longitudinal end e...In this paper, a simulation model of Permanent Magnet Linear Synchronous Motor (PMLSM) is established by using phase equations method. Special attention is paid to its structure and the influence of longitudinal end effect and the unbalance of current. The analytic method can be used for the analysis of dynamic and static characteristics of PMLSM.展开更多
The rejection properties of a nanofiltration organic membrane were investigated using KCI solutions, NaC1 solutions, NaC1/benzyl alcohol hybrid solutions and KCl/benzyl alcohol hybrid solutions. The presence of benzyl...The rejection properties of a nanofiltration organic membrane were investigated using KCI solutions, NaC1 solutions, NaC1/benzyl alcohol hybrid solutions and KCl/benzyl alcohol hybrid solutions. The presence of benzyl alcohol （3.7 mol · m-3） caused a decrease in electrolyte rejection within the range of 0 to 6%. The mechanism of the decrease was discussed. The cation-n bond was assumed to form in the hybrid solution and to further induce the partial dehydration of the cation. The steric and charge density inhibition of the salt activity was strengthened, and the salt rejection was thus decreased. A simulation was performed to evaluate the radius of the cation. 2015 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.展开更多
The goal of this paper is to analyze and propose a reconstruction of functional possibilities and database requirements of a Web based Educational Information system. For the research the Information system of the Tec...The goal of this paper is to analyze and propose a reconstruction of functional possibilities and database requirements of a Web based Educational Information system. For the research the Information system of the Technology School ＂electronic Systems＂ （TUES） associated with the Technical University of Sofia is on focus. The modules for admission of students, specialty classification, and graduation of students, management of the student＇s work in computer classrooms and lecturers＇ data management have been analyzed, developed and implemented. The additionally developed modules concern mainly the management of educational process and do not affect the e-learning or the official part modules. That led to the idea that the functionality for managing educational process has to be organized in a separate module defined as module for administrative services of educational process. Such restructuring of the system will bring flexibility in further growth of the system--for example students＇ admission or selection for different purposes.展开更多
文摘A more accurate analysis method on working modes is proposed by considering the winding terminal voltage and the eondueting power device as state parameters. For the three-phase hybrid excitation doubly salient machine （HEDSM） motor and its three-phase full-bridge inverter, in the proposed analytical method, all possible working modes are generally listed. Then, with the H_PWM-L_ON control strategy, the working modes are detailed with eorresponding equivalent circuits. Experimental results verify the robustness of the analysis.
文摘A new type of linear ultrasonic motor with two degrees of freedom (DOF) motion is presented. The concept of the new typical motor is based on the combination of a longitudinal and two bending modes. The construction and the operational principle of motor are described, and the elliptical motion of the driving point of the actuator is proved. Meanwhile, a prototype linear motor is designed by using the finite element method (FEM) and is constructed for experiments. The vibration modes are tested with the laser doppler vibrometer (PSV-300F), and the experimental results prove that the design requirements on the mode shape of the actuator and nature frequency are satisfied. The test run of the motor indicates that the operational principle of the motor and the design results are correct, and the output properties are also tested.
文摘To solve the problems of mechanical cam, tracking in an automatic welding machine, a new method of programmable logic controller ( PLC) tracking is presented. Based on analyzing the forming of welding tracking, a mathematical model of position control is set up. The experiments show that using a modified machine, PLC makes little welding positional error and can meet the product requirements.
文摘This paper proposes a new type of pulse launcher that applies the principle of linear motors. The stator, viz. gun barrel, of the launcher has a new structure of one segment of iron core consisting of 3 staggered laminations. This structure is helpful in advancing the thrust force per volume. Based on introducing the structure and the working principles, this paper resolves the electromagnetic thrusting force and performs mechanical analysis and experiments on the sample launcher. The research shows that this launcher is simple and brushless structure with brief controlling.
文摘Currently, the monitoring of bridges in China heavily relies on manual operation, which has several major problems. It generally takes a very long time to complete an inspection process on bridges. The manual data is sometimes unreliable or even wrong in the case of careless operation. The inspection activity itself is dangerous for inspectors, e.g., bridges are located in the sea or river. Some semi-automatic monitoring methods are recently employed, but they are either very expensive or do not work properly. Therefore, the traditional bridge monitoring process becomes an increasing challenge for bridge operators. In this paper, a real-time and automatic bridge monitoring system is presented to meet the bridge monitoring needs, and MEMS （Micro Electro Mechanical Systems） are the key building block in this system. By using the MEMS-based sensors, it is much more efficient and accurate in monitoring bridges with the measurement of inclination, acceleration, displacement, moisture, temperature, stress and other data.
文摘A new method for determining the incremental cohesion △Cm of surrounding rock due to prestressed cable anchor is presented, and the formulas for △Cm are deduced and △Cm distributions also are discussed, based on the two anchorage effects, one is the effect with the prestressed vaIue △σ3 of cable anchor improving the stress state of surrounding rock and increasing the surrounding rock strength, the other is the fully encapsulated effect. The determined incremental cohesion △Cm is subiected to the model test and field measurement in the references, and coincides well with those tested results. The formulas for △Cm can be used in designing supoport parameters and related numerical analyses of prestressed cable anchor.
文摘In this paper, a simulation model of Permanent Magnet Linear Synchronous Motor (PMLSM) is established by using phase equations method. Special attention is paid to its structure and the influence of longitudinal end effect and the unbalance of current. The analytic method can be used for the analysis of dynamic and static characteristics of PMLSM.
文摘The rejection properties of a nanofiltration organic membrane were investigated using KCI solutions, NaC1 solutions, NaC1/benzyl alcohol hybrid solutions and KCl/benzyl alcohol hybrid solutions. The presence of benzyl alcohol （3.7 mol · m-3） caused a decrease in electrolyte rejection within the range of 0 to 6%. The mechanism of the decrease was discussed. The cation-n bond was assumed to form in the hybrid solution and to further induce the partial dehydration of the cation. The steric and charge density inhibition of the salt activity was strengthened, and the salt rejection was thus decreased. A simulation was performed to evaluate the radius of the cation. 2015 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.
文摘The goal of this paper is to analyze and propose a reconstruction of functional possibilities and database requirements of a Web based Educational Information system. For the research the Information system of the Technology School ＂electronic Systems＂ （TUES） associated with the Technical University of Sofia is on focus. The modules for admission of students, specialty classification, and graduation of students, management of the student＇s work in computer classrooms and lecturers＇ data management have been analyzed, developed and implemented. The additionally developed modules concern mainly the management of educational process and do not affect the e-learning or the official part modules. That led to the idea that the functionality for managing educational process has to be organized in a separate module defined as module for administrative services of educational process. Such restructuring of the system will bring flexibility in further growth of the system--for example students＇ admission or selection for different purposes.
