基于GPS/INS的机载三线阵影像直接定位技术研究

介绍了机载线阵CCD传感器和POS／AV510系统的基本原理;推导了GPS／INS（惯性导航系统）的外方位元素的计算公式;通过实验获取了GPS／INS系统的外方位元素;重点介绍了用前方交会解求地面点坐标实现影像的直接定位方法。最后,对具体实验数据进行分析,得出了有益的结论。     

舟山教育学院会议中心AV多媒体系统设计

以舟山教育学院会议中心报告厅AV（音视频）多媒体系统设计为例，具体分析了该AV多媒体系统的组成形式和实现方法，并对AV多媒体技术在教育建设项目设计时需要考虑的一些问题进行了总结。     

Hemodialysis vascular access monitoring: Current concepts

Most arteriovenous grafts fail due to irreversible thrombosis, and most clotted grafts have an underlying stenotic lesion. These observations raise the plausible hypothesis that early detection of graft stenosis with preemptive angioplasty will reduce the likelihood of graft thrombosis. A number of noninvasive methods can be used to detect hemodynamically significant graft stenosis with a high positive predictive value. These tests include clinical monitoring, as well as surveillance by static dialysis venous pressures, flow monitoring, or duplex ultrasound. However, these surveillance tests have a much lower positive predictive value for graft thrombosis in the absence of preemptive angioplasty. In other words, none of the currently available surveillance tests can reliably distinguish between stenosed grafts destined to clot, and those that will remain patent without intervention. As a consequence, any program of graft surveillance necessarily results in a substantial proportion of unnecessary angioplasties. Moreover, a substantial proportion of grafts thrombose despite a normal antecedent surveillance test. Numerous observational studies have found an impressive reduction of graft thrombosis after implementation of a stenosis surveillance program. In contrast, 5 of 6 randomized clinical trials failed to show a reduction of graft thrombosis in patients undergoing graft surveillance, as compared with those receiving only clinical monitoring. The lack of benefit of surveillance is largely attributable to the rapid recurrence of stenosis after angioplasty. Thus, routine surveillance for graft stenosis, with preemptive angioplasty, cannot be recommended for reduction of graft thrombosis. Future research should be directed at pharmacologic interventions to prevent graft stenosis.     

Fuel properties of Brassica juncea oil methyl esters blended with ultra-low sulfur diesel fuel

Brassica juncea is a drought-tolerant member of the Brassicaceae plant family with high oil content and a short growing season that is tolerant of low quality soils. It was investigated as a feedstock for production of biodiesel along with evaluation of subsequent fuel properties, both neat and in blends with petroleum diesel fuel. These results were compared against relevant fuel standards such as ASTM D6751, EN 14214, ASTM D975, EN 590, and ASTM D7467. Crude B. juncea oil was extracted from unconditioned seeds utilizing a continuous tubular radial expeller. The oil was then chemically refined via degumming, neutralization and bleaching to render it amenable to direct homogeneous sodium methoxide-catalyzed transesterification. The principal fatty acid detected in B. juncea oil was erucic acid (44.1%). The resulting biodiesel yielded fuel properties compliant with the biodiesel standards with the exception of oxidative stability and kinematic viscosity in the case of EN 14214. Addition of tert-butylhydroquinone and blending with soybean oil-derived biodiesel ameliorated these deficiencies. The fuel properties of B5 and B20 blends of B. juncea oil methyl esters (BJME) in ultra-low sulfur (<15 ppm S) diesel (ULSD) fuel were within the ranges specified in the petrodiesel standards ASTM D975, EN 590 and ASTM D7467 with the exception of derived cetane number in the case of EN 590. This deficiency was attributed to the inherently low cetane number of the certification-grade ULSD, as it did not contain performance-enhancing additives. In summary, this study reports new fuel property data for BJME along with properties of B5 and B20 blends in ULSD. Such results will be useful for the development of B. juncea as an alternative source of biodiesel fuel.     

Effect of Acid Value on TBHQ and BHT Losses in Heating Oils: Identification of the Esterification Products of TBHQ and Free Fatty Acids

The loss of phenolic antioxidants is one of the major problems associated with the food frying process. As temperature increases and heating time is prolonged, losses of both tertiary butylhydroquinone (TBHQ) and butylated hydroxytoluene (BHT) are significantly increased. In this work, the effect of different types of free fatty acids (FFA) and the acid value (AV) of soybean oil (SBO) on TBHQ and BHT losses during heating were systematically studied. The results showed that the higher the AV of SBO at 120 or 180 °C, the greater the TBHQ loss. The type of FFA also had an observable effect on TBHQ losses at both temperatures, whereas FFA type had no effect on BHT losses. Employing high performance liquid chromatography and liquid chromatography–mass spectra (LC–MS analysis, it was determined that esterification of TBHQ with FFA (C_8:0, C_18:0, C_18:1) occurred at 120 or 180 °C, whereas esterification of BHT with FFA (C_8:0, C_18:0, C_18:1) in SBO was not observed. Nuclear magnetic resonance analysis showed that esterification occurred at the 4-position of TBHQ.     

智能大厦主控机音视频矩阵设计

给出了某智能大厦主控机中应用I2C总线以及I2C接口音视频矩阵芯片MAX4548来设计3路4×2音视频矩阵的具体方案,并对其软硬件设计作了详细说明。该方案具有功耗低,控制简单,占用系统资源少等优点,并已成功实现。     

电视机的AV切换电路设计

在电视机AV切换电路设计中,运用多路选择芯片CD4052BC进行多路音频的切换,通过单路视频输入和双声道音频输入协调TV信号及各路外部设备信号之间的关系,使其能正确在屏幕上显示和再现伴音,并对提高视频效果和AV切换能力的各方面因素作了详细介绍。     

基于MAX4548的3路4X2音视频矩阵设计

介绍了I2C总线以及I2C接口音视频矩阵芯片MAX4548的基本原理、3路4X2音视频矩阵的设计方案,具有功耗低,控制简单,占用系统资源少等优点并已成功实现。     

Homeplug AV over Coax系统设计

设计了一种基于Homeplug AV技术利用家用同轴电缆实现家庭HFC网的双向接入设备.介绍了整个系统的设计思路,并对Homeplug AV over Coax设备进行了测试,包括衰减、设备组网、网络节点、传输帧的大小对整个系统的吞吐量、延时的影响,得出其性能要比电力线上用好得多,并对Homeplug AV over Coax的应用前景作了分析.     

EOC技术在台州广电网络的应用

介绍HFC网络双向改造中的EOC技术背景、现状,对主要的EOC技术进行比较,分析各自适用的网络环境。最后介绍HomePlug AV技术方案在台州广电网络中的应用情况和注意事项。