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71.
基于EPA标准的执行机构产品开发   总被引:1,自引:2,他引:1  
介绍了基于EPA标准的执行机构的工作原理,详细介绍了EPA通信卡的硬件设计,并阐述了基于模块化的软件设计,主要包括EPA用户应用程序、EPA协议栈软件和硬件驱动等主要模块。从而使执行机构具有基于EPA标准的工业以太网通信能力,同时利用EPA标准的多信息传输能力,实现了执行机构的远程组态、远程标定和远程故障诊断等功能,达到了执行机构设备智能化、数字化和网络化的目的,具有广阔的应用前景。  相似文献   
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73.
Findings from epidemiological and observational studies have indicated that diets high in omega-3 polyunsaturated fatty acids (PUFAs) such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) may reduce the risk of cognitive decline and Alzheimer’s disease (AD). To determine if increasing intake of DHA and EPA through supplementation is beneficial to cognition and mood in individuals with cognitive impairment no dementia (CIND) or Alzheimer’s disease (AD) a four month, randomised, double-blind, placebo controlled study was conducted. Fifty-seven participants with CIND and nineteen with AD were randomised to receive either omega-3 PUFAs (600 mg EPA and 625 mg DHA per day) or placebo (olive oil) over a four month period. Elevating depleted levels of EPA and DHA through supplementation in individuals with CIND or AD was found to have negligible beneficial effect on their cognition or mood. These findings confirm an overall negligible benefit of omega-3 PUFA supplementation for those with cognitive impairment and dementia. More intervention studies need to be undertaken with longer study durations and larger sample sizes. It may prove fruitful to examine effects of different doses as well as effects in other dementia subtypes.  相似文献   
74.
Abstract Various studies on indoor and outdoor particulate matter in the urban environment in the vicinity of busy arterial roads in the centre of the subtropical city of Brisbane have indicated that the revised United States Environmental Protection Agency National Ambient Air Quality Standards (US EPA NAAQS) for Particulate matter PM2.5 could be exceeded not only outdoors but also indoors. The aim of this work was to investigate outdoor exposure to submicrometer particles and their relationship with indoor exposure in a hypothetical office building located in the vicinity of a busy arterial road. The outdoor exposure values and trends were measured in terms of particle number in the submicrometer size range and were then recalculated to represent mass concentration trends. The results of this study indicate that exposure to PM0.7 particles in ambient air close to a busy road often exceeds the levels of the annual and 24-hour US EPA NAAQS PM2.5 standards. It is likely that exposure to PM2.5 is even higher, and may significantly exceed these standards.  相似文献   
75.
本文介绍了导致电子产业中静电危害越发突出的原因,提出并详细论述了建立有效的静电控制程序应该遵循的四项原则。  相似文献   
76.
The effect of cooling rate on the degree of removal of saturated acyl groups from FFA derived from canola oil and the isolation of di- and polyunsaturated acyl groups from FFA derived from vegetable and fish oil, respectively, during urea inclusion compound (UIC)-based fractionation was investigated. Traditionally, slow cooling has been used (ca.−1°C min−1). A more rapid cooling rate (−47°C min−1) produced UIC crystals of similar morphology and thermodynamic properties, but of a size an order of magnitude smaller than the UIC formed during slow cooling. Fractionations used only renewable materials (urea, FFA, and 95% ethanol as solvent) and benign operating conditions (ambient pressure, 25–75°C, and neutral pH). When the recovery of FFA (in the solvent-rich phase) was relatively high (>60%), the selectivity of UIC-based fractionation toward the inclusion of saturated FFA and against polyunsaturated FFA was not affected by the cooling rate. In contrast, when the FFA recovery was low, representing cases in which an increase of the PUFA purity is a more important economic goal, a slower cooling rate resulted in a significantly greater discrimination against PUFA groups, hence to a FFA product with a measurably greater purity. This paper was presented at the 96th AOCS Anual Meeting and Expo, Salt Lake City, Utah, on May 4, 2005.  相似文献   
77.
文中介绍了一种利用EPA技术的在工业以太网上实现数据交换和总线供电的温湿度测量仪的设计方法。该温湿度测量仪的硬件设计方案包含微处理器、存储器、传感器模块、电源模块、网络通信接口等重要组成部分,详细介绍了EPA协议栈实现原理,并由上层组态监控软件完成对其测量数据的在线监测。该设计将数据传输和供电集中在一根网线上实现,降低了用户成本,有较好的市场潜力。  相似文献   
78.
79.
ABSTRACT: Canned tuna ( n = 240), salmon ( n = 16), and mackerel ( n = 16) were analyzed for mercury and fatty acids. Average mercury levels were 188, 45, and 55 ppb, respectively, and below the FDA Action Level of 1000 ppb. "Light tuna in water" contained lower mercury (x = 54 ppb) compared with "white/albacore tuna in water," which contained higher eicosapentaenoic acid/docosahexaenoic acid (EPA/DHA) x= 711 mg/100 g wet tissue). Mercury residues in salmon (x = 45 ppb) and mackerel (x = 55 ppb) were lower than in tuna products, but the EPA/DHA levels were higher (salmon, ×= 1623 mg/100 g wet tissue; mackerel, ×= 851 mg/100 g wet tissue). Information from this study will help women of childbearing age to limit their intake of mercury while obtaining healthy fats from fish.  相似文献   
80.
采用L18(37)正交法优化小球藻C95和小球藻C97的生长培养基,经15 L规模培养并收获小球藻;碱性乙醇法萃取游离脂肪酸,再经脲素包埋提取多不饱和脂肪酸,并用气相色谱检测二十碳五烯酸(eicosapentaenoic acid,EPA)的含量。研究结果表明:小球藻C95最优培养基(微量元素母液0.8 m L/L,维生素母液2.4 mL/L,NaH2PO4·2H2O6.0 g/L,Na2SiO3·9H2O 9.0 g/L,NaNO360.0 g/L,FeC6H5O7·5H2O 3.0 g/L);小球藻C97最优培养基(微量元素母液1.6 m L/L,维生素母液2.4 m L/L,NaH2PO4·2H2O 4.0 g/L,Na2SiO3·9H2O 11.0 g/L,NaNO380.0 g/L,FeC6H5O7·5H2O 3.0 g/L);小球藻C95和小球藻C97对数末期(分别是第4天和第5天)达到的细胞密度分别为9.53×10^7个/mL和8.91×10^7个/mL,EPA含量分别占总脂肪酸的30.2%和29.5%,小球藻C95的EPA含量要高于小球藻C97。  相似文献   
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