Applied Mechanics and Materials Vols. 130-134

Abstract: Rock mass is a multi-fractured body. Regardless of the size of these flaws, they can reduce the strength of rock materials [1]. As rock is not a transparent material, the process of deformation to failure is difficult to observe. Transparent brittle materials are able to solve this problem. This paper provides a production method of prefabricated defects. And the results prove that the frozen PMMA and glass are very similar with rocks in breaking process and mechanical properties.

Abstract: Several experiments undertaken on cement and mortar samples with internal cracks of different shapes and sizes demonstrated that 3-D cracks growth in compression was qualitatively different from the 2-D cases. This paper employs pre-existing cracks in frozen PMMA（polymethylmethacrylate plastic） which are produced by the mechanical method to analyze the evolution of the boundary effect of PMMA and to study the mechanisms of cracks growth and coalescence. In the experiments, 3-D cracks are tested under uniaxial compression and finally draw two conclusions about failure mechanisms of PMMA and brittle materials.

Abstract: This paper puts forwards the idea of using SRV1 as the platform and making a whole and integrated central air-conditioning duct cleaning system by combining lighting and cleaning devices with dust cleaning devices which all together could fulfill the task of cleaning the central air-conditioning ducts. With good mobility and extended function and also small in size,SRV1, which can also realize wireless remote control and trunking communication, is available for monitoring and cleaning all parts of the ducts simultaneously and can be applied in the complicated environment of the central air-conditioning ducts.

Abstract: With the development of integrated circuit technology, design for test (DFT) is on the agenda. In this paper, we propose a new method that the non-test part of a SIP chip can be easily tested with the boundary-scan test utilizing the boundary scan chain of the FPGA. The problem of no boundary scan test structure in one (or more) chip in a system-in-package (SIP) can be solved by connecting the interconnection (s) to be tested to the FPGA to form an enlarged boundary scan daisy chain.

Abstract: A new three-dimensional cubic chaotic system is reported. This new system contains five system parameters and each equation contains nonlinear term. Moreover, two equations of nonlinear term is cubic. The basic properties of the new system are investigated via theoretical analysis, numerical simulation, Lyapunov exponent spectrum, bifurcation diagram, Lyapunov dimension and Poincare diagram. The different dynamic behaviors of the new system are analyzed when each system parameter is changed .An electronic circuit was designed to realize the new chaotic system. Experimental chaotic behaviors of the system were found to be identical to the dynamic properties predicted by theoretical analysis and numerical simulations.

Abstract: In order to reduce the error of the phase lock-loop (PLL) and compensate the delay of the low pass filter on harmonics detection, In the paper, a detecting-method without PLL in single-phase circuit is researched. In this method, the PLL and LPF are omitted, the feedback and average theory are used, so that the problem of detecting accuracy induced by PLL and real-time induced by LPF is solved. It is testified through comparison, analysis and simulation, that both methods can reduce the latency, improve dynamic response speed, the feedback method can reduce the delay in a dynamic, continuous process, while the average theoretical method can reduce the delay quantitatively.

Abstract: Magnetic detection and localization is becoming a hot point in the past twenty years. Amorphous wire is a promising material to produce high performance magnetic sensor for GMI effect. A high sensitivity micro magnetic sensor is designed and a processing circuit is presented in this paper. Based on the processor TMS320F28335, the magnetic signal of ferromagnetic target can be sampled and processed.

Abstract: In order to realize high-speed and real-time communications between canbus and usb bus, a can/usb embedded adapter is designed in this paper. The hardware of the system consists mainly of AT89S51 as the local processor and PDIUSBD12 as the USB interface device, the sja1000 as the canbus interface device. Data communication is operated by the firmware and drivers. Adapter completely satisfies the needs of the CAN bus with its highest speed of 1Mps and it will be widely used in future for its high efficiency and low cost.

Abstract: For the requirement to control the content of traces SiO₄^-2 in the water and vapor in coal-fired power plants. By thie method of using spectrophotometry, the multichannel online monitoring SiO₄^-2 instrument is designed based on embedded system according to the Lambert-Beer theorem. The entire system is managed by the embedded real-time operating system uC/OS, based on the industrial grade embedded microprocessor AT9140800. The system satisfactorily realized the detecting of traces SiO₄^-2 in high purity water by the plunger pumps, cold light source monochromatic double paths optical system, “reversal reagent dosing” method. The experiments and field application show that the system has stably function, high intelligence grade, high test precision and good reproducibility, so it really meets the requirements of detecting traces SiO₄^-2 in different industries.

Abstract: By analyzing the limitations of existed offset optimization models about arterial control system, and according to the random distribution of road travel speed, we obtain the offset optimization algorithm and optimal signal timing parameters based on multi-attribute decision making methods, where road travel speed, delay and queue length are considered and inequality. Finally, the algorithm is applied to an arterial control system, and the simulation and the analysis of results are given by using Vissim. Results show that the optimized model can provide a new approach for offset optimization of arterial coordinate control system．