电力系统电压稳定性的预防与校正控制

针对世界上不同电力系统中报告的电压不稳定事故,详细介绍了利用电压不稳定指示器来预防与校正控制电力系统中的电压不稳定性问题。通过实际应用及时解决了许多电力系统的电压不稳定问题,消灭了隐患。     

矿用卡车示宽灯改造应用分析

随着露天矿产量及规模不断加大,矿用卡车也越来越大型化,卡车运行管理已成为露天矿生产安全主要方面。由于卡车行驶中盲区较大,且车体较大,尤其夜间作业,存在较大的安全风险,一旦发生安全事故会造成巨大的生命和财产损失。通过对矿用卡车夜间作业状态分析,提出矿用卡车示宽灯改造方案,在哈尔乌素露天煤矿应用实施,有效降低了卡车发生安全事故的概率及维护成本,也为露天矿安全、高效生产提供了保障。     

基于 FPGA 的机载水平状态指示仪

在对基于DSP＋FPGA方案进行改进的基础上,提出一种基于FPGA的机载水平状态指示仪硬件方案。该方案由FPGA完成画面的生成并控制帧存、驱动LCD;用DSP完成参数的计算;通过对称性简化计算;通过并行处理和硬件实现提高图形的生成速度。结果表明,该方案简化了系统结构,提高了水平状态指示仪画面的刷新速度及分辨率。     

荧光指示剂吸附法测量柴油馏分芳烃含量

应用液体石油产品(汽、煤油)中的芳烃标准分析试验方法——荧光指示剂吸附法测量柴油馏分烃类族组成,考察了硅胶,洗脱剂以及空气压力对实验结果的影响,对分析条件进行优化,确保分析的重复性和准确性。     

基于间接示功图测量的电潜柱塞泵故障诊断研究与应用

在分析电潜柱塞泵工作原理的基础上,结合柱塞式抽油泵的结构,建立了机组运行的理论示功图,对其进行了深入分析。以功率信号作为故障信息,提出一种基于间接示功图测量的电潜柱塞泵故障诊断方法,并描述了小波去噪方法绘制实测示功图的主要过程。针对机组典型故障,在室内模拟平台和现场油井上对该方法的准确性进行了验证实验与分析。测试结果表明:故障诊断效果较好。     

Consumption patterns,bacteriological quality and risk factors for Salmonella contamination in meat-based meals consumed outside the home in Kigali,Rwanda

Meat-based meals are consumed as a source of animal proteins and constitute one of the leading vehicles for food borne infections in humans. The main objective of this study was to determine the consumption pattern and the bacteriological quality of meat-based meals consumed outside households in Kigali. A survey on meat consumption patterns was carried out in 400 households by using a questionnaire, whereas different meat-based meals were sampled from 150 snack bars and restaurants. Enumeration of hygiene indicator bacteria (total mesophilic bacteria and Escherichia coli) and the qualitative detection of Salmonella were carried out by using conventional culture methods. The results indicated that goat was the type of meat that was consumed the most outside the home in Kigali and the meat intake varied significantly (p ≤ 0.05) with the social category of the household. The average levels of total aerobic bacteria and E. coli in meat-based meals were found to be 4.7 and 1.4 log cfu/g, respectively, whereas Salmonella was detected in 11.7% of all meat-based meals. Eight factors mostly linked to the cooking treatments and hygienic handling practices for cooked meals were found to be significantly (p ≤ 0.05) associated with the risk of Salmonella occurrence in meat-based meals consumed outside the home in Kigali. The findings from this study strongly suggest the need for proper cooking and/or improvements in hygiene in the establishments selling ready-to-eat meat-based meals in Kigali, particularly those located in rural localities.     

中和滴定法在生产中的应用

在强酸与弱酸、强碱与弱碱的生产中利用中和滴定法测定其含量的方法简捷、实用 ,测定的结果比较精确 ,应用范围广     

An innovative indicator of carbon dioxide emissions for developing countries: A study of Taiwan

Ever since the Kyoto Protocol entered into force, the issues of climate change and greenhouse gas (GHG) emissions have drawn more and more attention globally. However, the major concern of the Kyoto Protocol to reduce the overall GHG emissions might be inaccessible for most developing countries, which rely heavily on the energy-intensive industries for exports and economic growth. In this study, an innovative indicator of net carbon dioxide (CO₂) emissions, which excludes the emissions corresponding to the exports, is proposed to explicitly reveal domestic situations of developing countries. By introducing the indicator of net CO₂ emissions to top five energy-intensive industries in Taiwan, the analysis indicates that the increase in CO₂ emissions from 1999 to 2004 is mostly contributed by the expanded exports rather than the domestic demand. The distinct growth patterns of the apparent and net CO₂ emissions also imply the transformation of the industrial sector. It is expected that, for developing countries, the concept of net emissions may not only serve as a proper interim target during the process of international negotiations over GHG reductions but also highlights the prominence of addressing the emissions from the industrial sector as the top priority.     

Changes in volatile composition during fruit development and ripening of ‘Alphonso’ mango

BACKGROUND: Volatile blends of five developing and five ripening stages of mango (Mangifera indica L. cv. Alphonso) were investigated along with those of flowers and leaves. Raw and ripe fruits of cv. Sabja were also used for comparison. RESULTS: A total of 55 volatiles belonging to various chemical classes such as aldehydes, alcohols, mono‐ and sesquiterpene hydrocarbons, lactones and furanones were identified. In all Alphonso tissues monoterpenes quantitatively dominated, with 57–99% contribution; in particular, (Z)‐ocimene was found in the highest amount. Ripeness was characterized by the de novo appearance of lactones and furanones in the blend of monoterpenes. Sabja was distinguished by the abundance of monoterpene hydrocarbons in the raw fruit, and that of sesquiterpene hydrocarbons and their derivatives in the ripe stage. CONCLUSION: Various stages of the Alphonso fruit during transition from flower to ripe fruit are characterized by unique volatile signatures that are distinguished from each other by the qualitative and quantitative appearance of different volatile compounds. Thus volatiles can be highly informative markers while studying the development and ripening of mango. Copyright © 2009 Society of Chemical Industry