Advanced Materials Research Vol. 422

Abstract: In recent years, the prolific usage of nitrogenous fertilizers in the agricultural area of China has resulted in inefficient nitrogen usage, environmental pollution and the degradation of the soil fertility. As such, a rapid, low-cost and reliable soil detection method is urgently needed. This study reported on the laboratory evaluation of a solid-state ion-selective electrode, based on a nitrate doped polypyrrole polymer (PPy(NO3-)), for the simultaneous detection of soil nitrate-nitrogen. The potentiometric slope of these PPy(NO3-) electrodes for nitrate was found to be -(53.3±0.8) mV/decade over a linear range of three decades of concentration 10-4～10-1mol/L. It was also found that these electrodes had a nitrate detection limit of 5.0 ×10-5 mol/L. Impacts of soil extractant conditions were also tested. The electrodes displayed better performances for nitrate solutions with pH lower than 7.0. The potentiometric responses of electrodes exhibited a negative drift tendency of 0.6 mV/°C, which was probably caused by changes of the polymer morphology and the solution ionic activity. In order to reduce the interferences of coexisting anion, deionized water was chosen as soil extractant. It is shown that a fast determination of soil nitrate levels for site-specific control of fertilizer application could be realized using the PPy(NO3-) electrodes together with an automatic fluidic control system.

Abstract: Zn-Al-9-hydroxy-9-flourenecarboxylate-layered double hydroxide, ZAF nanocomposite was successfully synthesized by direct self-assembly method with Zn to Al molar ratio, R = 4 and 0.4 M 9-hydroxy-9-flourenecarboxylate, 9H9F. Due to the inclusion of a new anion, 9H9F basal spacing expanded from 8.9 Å in the Zn-Al-layered double hydroxide, ZAL to 13.2 Å in the ZAF. The FTIR spectra of the hybrid nanocomposite show resemblance peaks of the ZAL and 9H9F indicating the inclusion of the organic compound into the LDH interlamellae. The percentage loading of 9H9F was found to be 75.9 % (w/w). Sustained release of 9H9F from ZAF into various aqueous solutions was found to be dependent on the incoming anion, with the percentage saturated release of 94%, 72%, and 15% in sodium phosphate, sodium sulfate and sodium chloride aqueous solution 0.0005 M, respectively. This study indicates that ZAL can be used as a host carrier for plant growth regulator, 9H9F with sustained release capability.

Abstract: In an electric power steering (EPS) system, it is important to make a precise and reliable measurement of the torque on the steering wheel. A non-contact torque sensor has been developed for EPS system. The sensor is based on a magnetic principle that the magnetic flux path is changed with the torsion of a torsion bar which is placed in the steering shaft. The change of magnetic flux density in the working airgap is detected by a standard Hall-effect IC. The sensor has broad prospects for its good performance, simple structure and low cost. This paper introduces the torque sensor’s working principle, analyzes the magnetic circuit by 3D simulation, and concludes its key technologies and development trends.

Abstract: Hydraulic drive mixers are widely employed to process the cohesive mixture, especially the energetic mixture. According to the mathematic models of main links of the speed regulating system of a hydraulic drive planetary mixer, a simulation model for the system was presented in this paper. The load and impulsion have impacts on the speed response of the speed regulating system with good performance of stability. The converted rotary inertia of the hydraulic motor has a two-sided impact on the speed regulating system, namely impact the response and the overshoot performance at the same time. And, the leakage of the hydraulic drive system often has a bad impact on the speed response of the regulating system.

Abstract: Compared with the difference template matching algorithm, which is low efficiency and poor results, the improved difference template matching algorithm is proposed. Firstly, the model is subdivided into blocks that are clustered along the neighbor areas. Then, a point is set in every sub model. Furthermore, the different template matching, used in small local flied concurrently, to fix the cell center point and set the cell area circumference. Experimental results show that the proposed algorithm is effective and robust.

Abstract: The bearing of rotating machinery often fails due to the frictional forces of rolling element, in the early stages of the faults, a series of ultrasound can be generated in short time intervals, which occur at bearing characteristic frequencies. Since the frequencies of ultrasonic signal are very high, they will lead to much higher computing burden when using the common technique of Fast Fourier Transforms (FFT) directly. In this paper, envelope detection technology and heterodyne technology which integrated in an ultrasonic data collection system are used to reduce the frequency effectively. To allow for the easier detection of the bearing faults, these two techniques has been used together with FFT. A verification research with respect to vibration analysis is carried out to analyze the effectiveness and superiority of ultrasonic data collection in time domain and frequency domain aspects respectively. Extensive experiments have been performed in an Alternating Current (AC) motor system, and the results indicated that this ultrasonic data collection system is as useful as vibration analysis system in diagnosing the faults of bearings. In addition, it is more sensitive in fault diagnosis in the early stages of the bearing faults than vibration acquisition system.

Abstract: This paper studies algorithm of the giant die forging press control system of main loop, based on the national major science and technology project (2009ZX04005-011).Finally the design of the main oil system of Large die forging press is based on the single neuron adaptive PID control of quadratic performance index the learning algorithm. This system uses the system view. In the theory of controlling, the control model of each part is hard to be precise. We can also get relatively precise system using the method of system. In this paper, this system simulates in the MATLAB. The simulation results show that the control system has the high response speed, higher stability precision, strong disturbances ability, strong robustness and adaptive ability.

Abstract: Assembly is an important process in the manufacturing processes. For the badly self-adaptive and flexibility, the stuck phenomena and inefficient are often occurred with certain the assembly precision and fit, by using the robot for assembly. In this paper, the kinematics analysis of the three joints robot, which is used to assembly the bearing, is analyzed; the end joint movement angle formula is calculated. The force sensor is used during the assembly process. To ensure the assembly process, a new way is proposed to find the compliant assembly centre, which help the assembly robot to complicate the assemble process. The bearing assembly process is introduced by the three joint robots system.

Abstract: Pd nanocrystals embedded in TiO₂ film are formed in a self-assembly manner by rapid thermal annealing (RTA) of reactively co-sputtered TiPdO films. The cross-section transmission-electron microscopy (TEM) image and X-ray photoelectron spectra (XPS) reveal that the RTA at 800°C for 15 s results in the formation of Pd nanocrystals with an average size of around 10 nm. Further, the metal-oxide-semiconductor (MOS) capacitor with Pd-nanocrystals-embedded TiO₂ film sandwiched between Al₂O₃ layers has been fabricated and characterized electrically in comparison with the counterpart without Pd nanocrystals, indicating that the formed Pd nanocrystals are dominant charge storage nodes. The fabricated MOS capacitor with Pd nanocrystals exhibits obvious memory characteristics, demonstrating a C-V hysteresis window of about 8.2 V at the sweeping voltage rang of +/-9 V, a flatband voltage shift of ~2V under a constant voltage stress of +9V for 10ns corresponding to a charge injection speed of 6×10¹² cm^-2μs^-1. The underlying mechanisms of the memory characteristics under different C-V sweeps have also been discussed.

Abstract: This paper introduces the principle and method of PoE,and adopts LTC4263 and LTC4257 to design the system of PoE compliant whit IEEE802.3af, and realize the circuit. The design can provide DC for low power dissipation LXI、IP phone、AP、IPCAM and some terminals base on ethernet, when they are transfeting the data signal. As adopted double power supply, it can improve the transmission current, to improve output power, can make the capacity of electric power supply of PoE move higher, and can be power supply mode of general-purpose equipment.