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Micro-gear part is processing by using bio-etching method, Thiobacillus ferrooxidans (T.f.) is used as etching medium, and Leathen culture medium is selected as culture medium of T.f. The qualities of micro-gear are analysed by using 3D microstructure system of large depth of field. The experimental result showed that micro-gear part can be processed by using bio-etching method, and its teeth is full...
Tungsten, cobalt, iron and other metal elements will be moved when the cemented carbide tool is used to cut steel. The mobility will be reduced when water-based cutting fluid is used, but some elements in water-based cutting fluid will result in the hydration of tungsten carbide and cobalt in cemented carbide tool. This paper will research on the hydrolysis phenomenon of the tungsten carbide and cobalt...
Eucalyptus urograndis leaves are cheap and fine natural resources. Therefore, GC/MS was used to analyze high-grade bioenergy utilization of acetone extractives of Eucalyptus urograndis leaves. 43 compounds in the extractives were identified. The mainly abundant constituents were 1,2,3-butanetriol (33.25%), ethyl.alpha.-d-glucopyranoside (13.48%), thiazolidin-4-one, 3-(9H-xanthen-9-yl)-2-thioxo- (12...
At present, the fan-coil unit in China commonly works under wet cooling conditions in summers, which has certain disadvantages. Dry fan-coil unit, however, as an air conditioning system to be worthy of promotion, still has difficulty in dealing with fresh air with a big enthalpy difference. Air-to-air total heat exchanger (THX) is an efficient heat recovery device with capability of reusing the energy...
The longitudinal and torsional vibration of a lead-screw usually limits the closed-loop performance of a high-speed ball-screw drive system. It is difficult to accurately characterize the high frequency dynamics of the ball-screw drive system via a traditional lumped modeling method. This paper proposes a hybrid parameter modeling method. The model contains a distributed parameter model of the lead-screw...
A new type of high speed vertical machining center which adopt gantry type structure is introduced. And study on influence of guide screw as a significant part in static and dynamic analysis. In this paper, it is proved that results will be accurate, if guide screw is considered when processing a static and dynamic analysis. Finally conclude a precise method of carrying on static and dynamic analysis...
The technique of three dimensional solid element model and assembly was used to determine the temperature field of radial-flow impeller. The FEM software Cosmos was applied to analyze model system, and the precise analytic results were obtained. The results show that the analytic model can reflect the stead-state and transient temperature field characteristics of impeller directly, and thus can be...
A family of spherical parallel mechanisms which have fully decoupled motions is presented in this paper. The condition required for synthesizing the fully decoupled parallel mechanism is derived from the screw formulation of Jacobian matrix. According to this condition, several novel decoupled spherical parallel mechanisms are obtained. The decoupled motions are validated by the simulation of the...
In this paper, the pure torsion vibration model of the planetary gear trains for the increasing gearbox is proposed. The influence coefficient method is used to deduce the system dynamic equations. The dynamic equations are solved considering the variable meshing stiffness and the constant meshing damping. Finally the non-linear dynamic characteristics are analyzed carefully.
In this paper, according to the technical characteristics of the maintenance of cable of cable-stayed bridges, a new robot for cable maintenance is developed. The climbing equipment, the surface inspection equipment and the internal defects inspection equipment, the cleaning equipment, the spraying equipment for cable maintenance are all designed as reconfigurable module. According to different cable...
This paper designs an embedded displacement measuring device based on error separating technique of multi-circle overlapping three-probe method. Considering the requirement of high precision and high speed of modern CNC machine, high accuracy CCD laser displacement sensor is used in the system to measure the rotating spindle, and then the device send the result to PC for further analysis by error...
A loading and testing system was developed by utilizing the technology of computer and hydraulic, which was employed to test the performance and quality of the maintained shearer haulage part. This paper was focused on the introducing on this system's theory of testing and loading, basic structure, and key devices. This system achieved the all experiments for the performance of the shearer haulage...
Crane and its industry play a very important role in the national economy. At present, the crane industry developed more and more mature, but the development of crane's monitoring device is lagging. These factors affect the further improvement of the level of the whole crane industry. At the same time, these factors also lead to the user's difficult and ineffective management of the crane's monitor...
Inverted pendulum system is typical multi-variable, nonlinear, strong -coupling and instability naturally, as a typical control target, it has been subjected to many experts and scholars' concern. This paper derives the mathematical model for system of single link rotary inverted pendulum from Lagrange Equation, and through the linear model, the inverted pendulum is kept stable on the inverted point...
With the increasing number of vehicle-mounted electronic devices, the traditional communication mode of point-to-point connection cannot meet the requirements, in order to overcome the limitations of the traditional communication mode, to realize DS(data sharing), to carry out real-time control of driving conditions, CAN bus technology came into being. The technology has advantages of compact structure,...
Slewing bearing is usually designed based on the traditional bearing theory, but the calculation parameters are determined by a large number of experimental data, therefore, the experimental directly determines the reliability and accuracy of the design calculation of the slewing bearing. In this paper, slewing bearing and its experimental techniques are introduced, then, the NJUT-I test system is...
In response to the needs of customers and to improve the quality of the products along with rapidly changing technologies, quality evaluation of computer numerical control (CNC) machine tools is an important issue not only for manufacturers but also for customers. A multiple quality characteristics (QCs) decision model is presented in this paper to evaluate the quality of CNC machine tools by using...
The recent focus on improving the performance of construction cost control for highway project in China has led to a demand from industry for approaches that can cope with increasing complexity. Whilst many existing research now providing the methods to control for deviation from cost standards after finding cost variance, other factors such as component cost risk are still widely ignored. CRCS/CCS,...
In mountain area, terrain is one of the main safety threats for rescue helicopter. The contour map can tell pilot accurate terrain threats information, but it is difficult for a pilot to choose the best rescue route in complex area. Feasible routes set with protected airspace can be obtained by using image processing and image morphology technique, then heuristic path searching A* algorithm can be...
Trip assignment for urban traffic system is not only the basis for urban transport planning but also one of the key indicators of urban transport development. On the basis of the component analysis of urban transport system, `mode-route' map is put forward to describe the whole travel process and three-dimensional space-time operating diagram is also constructed to reflect the competitive nature on...
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