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161.
本文介绍了一种图像声纳测试系统的设计与实现。该型测试系统既可用于声透镜成像质量的分析,也可用于数字图像声纳波束形成质量的测试。该测试系统模拟部分共有96个通道,数字部分用7片DSP(TMS320C64×)芯片构成高速数据并行处理模块。声信号的原始数据或处理后的数据都可以用高速串行芯片传输至水面单元,经过对数据计算分析,可以获得声透镜成像的质量,或数字图像声纳波束形成的最佳参数。水池测试结果证明该测试系统实用便捷,性能稳定。  相似文献   
162.
本研究对高级象牙瓷坯泥的增塑与半成品的工艺控制进行了系列试验,使大件产品成坯率由20%提高到80%以上。  相似文献   
163.
This paper reports the synthesis of various molar concentrations of manganese (Mn)-doped Ultra-High Surface area Activated Carbon (USAC) additives and their efficient use as cathode materials for supercapacitors. We synthesized the nanoparticles via a novel and facile dip-coating process and characterized them in detail by various analytical techniques. The SEM, EDAX, and XPS results showed that the Mn ions were successfully substituted on the USAC additives’ layered structure without any structural changes. The long cyclic stability of the as-prepared Mn-doped USAC additives was tested as a cathode material for supercapacitors at different current densities. The detailed experimental results showed that the Mn dopant content crucially determines the electrochemical performances of the USAC additives. Electrochemical measurements showed that the MnCEP-S600HTT with 0.10 mol% molar concentration of Mn dopant gives the best cycling performances. It delivers a discharge capacity of 262.9 mAh g?1 after 100 cycles. Further increasing the current density to 1000 mA g?1 allowed it to still maintain 253.6 mAh g?1 after 200 cycles. We confirmed that the structure of Mn-doped USAC additives is an important pole to improve the structural stability and electrochemical properties.  相似文献   
164.
SCARA机械臂在工作过程中和工作终止后都会出现振动问题,为了降低机械臂的残余振动,选取粒子群作为寻最优抑振轨迹的优化算法,针对粒子群算法在轨迹寻优时收敛性差以及出现停滞现象问题,提出采用非线性递减惯性权重和粒子种群跳跃的方法对粒子群算法进行改进。利用机械臂振动抑制实验平台,使用改进的粒子群算法进行抑振轨迹优化并进行实验研究,验证结果可行且有效,得到抑振指标最小的最优抑振轨迹。  相似文献   
165.
Synthetic vision systems (SVS) render terrain features for pilots through cockpit displays using a GPS database and three‐dimensional graphical models. Enhanced vision systems (EVS) present infrared imagery of terrain using a forward‐looking sensor in the nose of an aircraft. The ultimate goal of SVS and EVS technologies is to support pilots in achieving safety under low‐visibility and night conditions comparable to clear, day conditions. This study assessed pilot performance and situation awareness (SA) effects of SVS and EVS imagery in an advanced head‐up display (HUD) during a simulated landing approach under instrument meteorological conditions. Videos of the landing with various HUD configurations were presented to eight pilots with a superimposed tracking task. The independent variables included four HUD feature configurations (baseline [no terrain imagery], SVS, EVS, and a combination of SVS and EVS), two visibility conditions, and four legs of the flight. Results indicated that SVS increased overall SA but degraded flight path control performance because of visual confusion with other display features. EVS increased flight path control accuracy but decreased system (aircraft) awareness because of visual distractions. The combination of SVS and EVS generated offsetting effects. Display configurations did not affect pilot spatial awareness. Flight performance was not different among phases of the approach, but levels and types of pilot SA did vary from leg to leg. These results are applicable to development of adaptive HUD features to support pilot performance. They support the use of multidimensional measures of SA for insight on pilot information processing with advanced aviation displays. © 2012 Wiley Periodicals, Inc.  相似文献   
166.
167.
This paper studies distributed filtering‐based ssynchronization of diffusively state‐coupled heterogeneous systems. For given heterogeneous subsystems and a network topology, sufficient conditions for the filtering‐based synchronization are developed with a guaranteed performance. The estimation and synchronization error dynamics are obtained in a decoupled form, and it is shown that the filter and the controller can be designed separately by LMIs. The feasibility of the proposed design method using LMIs is discussed, and the main results are validated through examples with various setup. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   
168.
Changes in β-glycosidase activity, total phenolic and isoflavone contents, and antioxidant activities during the fermentation of brown soybeans (Galmi) fermented food cheonggukjang by the potential probiotic Bacillus subtilis CSY191 were investigated. The total phenolic and isoflavone-glycoside and -aglycone contents as well as ABTS radical scavenging activity and FRAP assays of extracts increased, but malonylglycoside content decreased after a steaming process. It was found that fermentation enhanced the total phenolic and isoflavone-aglycone and -malonylglycoside contents, corresponding to antioxidant activities increased, but isoflavone-glycoside content decreased. The highest levels of daidzein, glycitein, and gensitein were present at concentrations of 156.5 μg/g, 10.2 μg/g, and 2.5 μg/g after 48 h of fermentation. In addition, ABTS radical scavenging activity and FRAP assay increased significantly during fermentation. We suggest that the high antioxidant activity of cheonggukjang of brown soybeans might be related to the markedly higher levels of total phenolic content and isoflavone-aglycones achieved during fermentation.  相似文献   
169.
Underlying reasons for waxy rice flours having different pasting properties   总被引:1,自引:0,他引:1  
The underlying reasons for three waxy rice varieties, Yang-fu-nuo (Y), Su-yu-nuo (S), and Guang-ling-xiang-nuo (G), having different flour pasting properties were examined. The pasting properties of the isolated waxy rice starches did not correlate with those of the corresponding waxy rice flours. Examining the pasting properties of the flours in 0.5 mM AgNO3 solution, treated with dithiothreitol and protease, suggested that rice protein and amylase activity were the main causes of the pasting property differences among the rice starches and flours. Starch isolated from Y flour had a larger proportion of A and B1 chains, longer average chain length and longer exterior chain length, which explained its higher gelatinisation temperature, higher pasting consistency, greater extent of retrogradation, and the firm texture of cooked Y rice.  相似文献   
170.
本文研究了辣椒籽油的提取方法,采用三因素三水平正交试验方案,考察了料液比、温度、时间对辣椒籽油及辣椒素提取的影响。同时,采用气相色谱面积归一化法测得辣椒籽油主要由棕榈酸、硬脂酸、油酸、亚油酸和亚麻酸组成。  相似文献   
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