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基于全电子设计方案的区域计算机联锁系统 总被引:2,自引:0,他引:2
介绍了基于全电子设计方案的区域性计算机联锁控制系统的技术方案和系统构成。详细阐述了系统中主控站和被控站设备的组成、功能和特点,给出了系统详细的结构框图。系统对于降低工程造价、充分发挥计算机性能、提高运输组织效率具有重要作用。 相似文献
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Pille Mänd Lea Hallik Josep Peñuelas Pierpaolo Duce Claus Beier János Garadnai Inger Kappel Schmidt Patricia Prieto Joke W. Westerveld 《Remote sensing of environment》2010,114(3):626-297
The aim of this study was to evaluate the use of ground-based canopy reflectance measurements to detect changes in physiology and structure of vegetation in response to experimental warming and drought treatment at six European shrublands located along a North-South climatic gradient. We measured canopy reflectance, effective green leaf area index (green LAIe) and chlorophyll fluorescence of dominant species. The treatment effects on green LAIe varied among sites. We calculated three reflectance indices: photochemical reflectance index PRI [531 nm; 570 nm], normalized difference vegetation index NDVI680 [780 nm; 680 nm] using red spectral region, and NDVI570 [780 nm; 570 nm] using the same green spectral region as PRI. All three reflectance indices were significantly related to green LAIe and were able to detect changes in shrubland vegetation among treatments. In general warming treatment increased PRI and drought treatment reduced NDVI values. The significant treatment effect on photochemical efficiency of plants detected with PRI could not be detected by fluorescence measurements. However, we found canopy level measured PRI to be very sensitive to soil reflectance properties especially in vegetation areas with low green LAIe. As both soil reflectance and LAI varied between northern and southern sites it is problematic to draw universal conclusions of climate-derived changes in all vegetation types based merely on PRI measurements. We propose that canopy level PRI measurements can be more useful in areas of dense vegetation and dark soils. 相似文献
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Michael J. WesterYuzita Yaacob Stanly Steinberg 《Mathematics and computers in simulation》2011,82(1):79-101
We use the cylindrical algebraic decomposition algorithms implemented in Mathematica to produce procedures to analytically compute integrals over polynomially defined regions and their boundaries in two and three dimensions. Using these results, we can implement the divergence theorem in three dimensions or the Green's theorems in two dimensions. These theorems are of central importance in the applications of multidimensional integration. They also provide a strong correctness test for the implementation of our results in a computer algebra system. The resulting software can solve many of the two and some of the three dimensional integration problems in vector calculus textbooks. The three dimensional results are being extended. The results in this paper are being included in an automated student assistant for vector calculus. 相似文献
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Eric R. MacamAuthor VitaeBryan M. BlackburnAuthor Vitae Eric D. WachsmanAuthor Vitae 《Sensors and actuators. B, Chemical》2011,158(1):304-312
The intent of this work is to look at the effects of varying the La2CuO4 electrode area and the asymmetry between the sensing and counter electrode in a solid state potentiometric sensor with respect to NOx sensitivity. NO2 sensitivity was observed at 500-600 °C with a maximum sensitivity of ∼22 mV/decade [NO2] observed at 500 °C for the sensor with a La2CuO4 electrode area of ∼30 mm2. The relationship between NO2 sensitivity and area is nearly parabolic at 500 °C, decreases linearly with increasing electrode area at 600 °C, and was a mixture of parabolic and linear behavior 550 °C. NO sensitivity varied non-linearly with electrode area with a minima (maximum sensitivity) of ∼−22 mV/decade [NO] at 450 °C for the sensor with a La2CuO4 electrode area of 16 mm2. The behavior at 400 °C was similar to that of 450 °C, but with smaller sensitivities due to a saturation effect. At 500 °C, NO sensitivity decreases linearly with area.We also used electrochemical impedance spectroscopy (EIS) to investigate the electrochemical processes that are affected when the sensing electrode area is changed. Changes in impedance with exposure to NOx were attributed to either changes in La2CuO4 conductivity due to gas adsorption (high frequency impedance) or electrocatalysis occurring at the electrode/electrolyte interface (total electrode impedance). NO2 caused a decrease in high frequency impedance while NO caused an increase. In contrast, NO2 and NO both caused a decrease in the total electrode impedance. The effect of area on both the potentiometric and impedance responses show relationships that can be explained through the mechanistic contributions included in differential electrode equilibria. 相似文献
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利用当今主流的组网技术、网络安全技术、主机技术及存储备份技术,结合以应用为导向的设计思想,对某市美术馆计算机信息网络系统进行了方案设计。整个设计采用分功能区模块化的设计方法,具有贯穿整体的集成性、扩展性、兼容性。 相似文献