Applied Mechanics and Materials Vols. 541-542

Abstract: Differential pressure flow meter is a kind of very promising flow measuring instrument, the application range is very wide. But aiming at the defects that the mechanical structure of all kinds of existing flow meters is complex, the throttling way disturbs the fluid greatly and the stability of differential pressure signal is insufficient, a kind of new inside and outside tube differential pressure flow meter was designed.

Abstract: Calculation fluid dynamics software Fluent was used to conduct three-dimensional numerical simulation on gas-liquid two-phase flow field in a wet flue gas desulfurization scrubber. The k-ε model and SIMPLE computing were adopted in the analysis. The numerical simulation results show that the different gas entrance angles lead to internal changes of gas-liquid two-phase flow field, which provides references for reasonable parameter design of entrance angle in the scrubber.

Abstract: Certain type of microwave range finder has been designed by adopting the technologies of DDS (direct digital frequently synthesis) digital signal synthesis and online signal detection, synthetically applying equal-accuracy frequency measuring method, automatic control of frequncy drift and quick interpolation method, combining WINDOWS API programming, Labview programing and fault disgnosis expert system. Eventually, accuracy verification and fault defect of microwave range finder are accomplished.

Abstract: This paper presents a design and implementation of an efficient and low cost system for indoor monitoring of human intrusion. The system design is based on the use of already available pyroelectric infrared passive sensors (PIR) that are able to detect thermal perturbation caused by moving objects within their field of view (FOV). Our design uses the PIR sensors in the geometric context as binary detectors with adaptive threshold estimation. The combined field of view of three PIR detectors is modulated by a custom designed lens mask to estimate the bearing angle of the single human intrusion. The prototype is formed by a sensing module routed wirelessly to another host module to visualize processed raw data.

Abstract: Aiming at requirements to depict engagement process of the hardware in loop simulation system of antiaircraft missile based on industrial computers for operational training simulation, the paper establishes the guidance and trajectory mathematical models for the process of antiaircraft missile attacking target. According to the result of missile velocity simulation by means of a trajectory simulation system of six degrees of freedom of an antiaircraft missile, a realistic mathematical model of the missile velocity parameter is established; a realistic mathematical model of a missile single shot kill probability (SSKP) is established with relative kill area data of a missile. The simulation model of the missile engagement process is implemented with VC++, which could be used to really simulate a whole engagement process of a missile flying and destroying a target. The experiments indicate the model is correct, the result is credible, the method is effective, and the thought solving the mentioned problem is very helpful for improving operational ability of personnel with similar training simulation system.

Abstract: Efforts to prepare for a growing number of elderly patients, reducing the escalation of healthcare costs, and avoiding hospitals emergency room overcrowding are some of the driving forces for adopting wireless healthcare monitoring systems. However, due to the open-to-air commination nature of multilayer wireless networks, it is important to consider reliability, accuracy, security and privacy of such data transmission. We have developed a low-cost and wireless telehealthcare system for monitoring of basic physiological parameters and automatically transmitting the measured data to an electronic patient record. It employs off the shelf wireless products and a secure web-based application which have been tested in a hospital with satisfactory outcomes.

Abstract: Star shot analysis is one common and important module in physics quality assurance (QA) which is regularly performed on the radiotherapy machine. A star shot analysis method by image processing is proposed. First, through ROI selection and image binarization, the irrelevant image parts are excluded and the star-shots are highlighted. Then the center and beam branches of the shots are determined by iteration, coordinate transformation, threshold values analysis and image segmentation. Finally, beam center lines and a minimum circle encompassing beam intersections are calculated by mathematic operations. The proposed method is performed on three star shot films and all beam center lines, beam intersections and minimum circles are obtained instantly and showed clearly. The results present good consistency with the commercial verification software and indicate that the proposed method provides the physicist a considerable comparison in physics QA.

Abstract: Fractional-order linear switched system (FLSS) is an important system of hybrid systems. In this paper, by using the analytical solution of FLSS, the necessary and sufficient condition on controllability and reachability of FLSS is given, respectively. The condition shows that if every subsystem is controllable (reachable), then the whole system is also controllable (reachable) for arbitrary switching rules. And if the whole system is controllable (reachable) for arbitrary switching rules, then every subsystem is controllable (reachable).

Abstract: By the reason of the additional side force acting on the force transducers affecting the rotation effect of the combinatorial load cell,the paper describes the effect of the spherical plain thrust bearings structure on the additional side force. A three-dimensional finite element model of the late-model high-accuracy combinatorial load cell was established and analyzed. From the results, it shows that the magnitude of the additional side force fluctuation increases with the height of the bearing base increasing. At the same time, the magnitude decreases with the friction coefficient of the inner and outer ring of bearing increasing. The results provide guidance for the design of the combinatorial load cell.

Abstract: On basis of two-phase flow and the heat transfer theory, the velocity and temperature of the liquid lend-bismuth eutectic were calculated with gas-injection and without gas-injection by FLUENT code, in the calculation segment. The radial velocity profiles and temperature profiles were acquired at different cross section. Analysis results show that: no matter the argon is existence or not, the velocity distribution and the temperature distribution have a good symmetry. Temperature rise of the liquid lend-bismuth eutectic with gas injected is larger than without argon. It is shown that the gas-injection is good for heat transfer of liquid lend-bismuth in the calculation segment.