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61.
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This article considers a discrete sequential multilevel automated system for recording electron-diffraction patterns. A comparative analysis is presented, along with experimental results that make it possible to evaluate the effectiveness of the technical decisions on which the device is based. The general design of the system is presented. Translated from Izmeritel'naya Tekhnika No. 5, pp. 16–18, May, 1996.  相似文献   
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It is well known that angles in composite parts contract as they are cooled down from the curing temperature, this is often referred to as spring-in. It is caused mainly by the significantly different thermal contractions and cure shrinkage's experienced between the fibre direction and the through-thickness direction during the manufacturing process. A number of works have reported on the spring-in of straight angle composite parts. However, little has been done to investigate the distortion of curved flanged composite parts, which will distort differently owing to the introduction of the additional curvature, thus constraint.

In the present work, the distortion of the circularly curved flanged laminates is studied numerically. The finite element method is used to predict the processing-induced distortion of the part with two different approaches. In the first approach, the shear angles of the composite plies are predicted by a draping analysis. The effect of the fibre shearing on the mechanical properties of the laminates is considered in the model used to predict the distortion. The second simplified approach assumes that the in-plane properties of the laminates are isotropic. The results obtained by these two approaches are compared with those obtained experimentally.  相似文献   

65.
A technique for SiO2 formation by liquid-phase deposition (LPD) at nearly room temperature for low-temperature processed (LTP) polysilicon thin-film transistor (poly-Si TFT) was developed. LPD SiO2 film with a lower P-etch rate shows a dense structure. LPD SiO2 also exhibits good electrical characteristics. LTP poly-Si thin-film transistors (TFTs) with LPD SiO 2 as the gate insulator have been fabricated and investigated. Their characteristics indicate performance adequate for their use as pixel transistors in liquid crystal displays (LCDs)  相似文献   
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OBJECTIVE: To evaluate the therapeutical mechanism of Bushen Shengxue Paste (BSSXP) on anemia. METHODS: Chronic renal failure induced anemia patients were treated with BSSXP, clinical manifestation, anemia and renal function as indicators were observed in patients. The erythropoietin (EPO) and inhibition of colony-forming unit-erythrocyte (CFU-E) in patients' serum were determined by CFU-E in vitro. RESULTS: The patients' symptoms, renal function and anemia were improved after administration with BSSXP 1-2 course. EPO in serum was slightly increased. The inhibition of CFU-E in patient's serum was significantly decreased. CONCLUSIONS: BSSXP could improve the anemia degree, its mechanism might be through clearing the inhibitor of CFU-E in serum.  相似文献   
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Voltage stability problems have been one of the major concerns for electric utilities as a result of system heavy loading. This paper reports on an investigation on the application of ANNs in voltage stability assessment. A multilayer feedforward artificial neural network (ANN) with error backpropagation learning is proposed for calculation of voltage stability margins (VSM). Based on the energy method, a direct mapping relation between power system loading conditions and the VSMs is set up via the ANN. A systematic method for selecting the ANN's input variables was developed using sensitivity analysis. The effects of ANN's training pattern sensitivity problems were also studied by dividing system operating conditions into several loading levels based on sensitivity analysis. Extensive testing of the proposed ANN-based approach indicate its viability for power system voltage stability assessment. Simulation results on five test systems are reported in the paper  相似文献   
70.
One-dimensional mathematical modeling was used to describe the self-propagating high-temperature synthesis (SHS) process for preparing TiAl3 and Ni3Al intermetallics. The kinetic parameters (activation energies and pre-exponential factors) for the two compounds were obtained by matching experimental measurement and the numerical solution. The results thus obtained were compared with rate parameters obtained using different methods. The activation energy was 483 and 283 kJ mol?1 for the formation of TiAl3 and Ni3Al, respectively. The temperature profiles calculated using the mathematical model were compared with experimental measurements for both aluminides which indicated reasonable agreement. Fine particle size and moderate preheating increase the SHS rates.  相似文献   
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