状态时滞系统故障诊断问题的LM I方法研究

应用H∞控制技术，探讨具有不确定输入以及状态时滞系统的鲁棒故障诊断（FD）问题。以残差对扰动信号L2增益体现其对扰动的鲁棒性，而以其对故障信号的L2增益体现残差对故障信号的灵敏度，研究基于状态观测器的FD系统设计线性矩阵不等式（LMI）方法，给出并证明解存在的条件以及观测器增益矩阵的求解方法。最后通过一个简例说明了算法的有效性。     

低压电弧短路电流计算

根据大量低压电弧短路实验的结果，用概率统计方法导出低压电弧短路时的电弧电压模型及电弧短路电流的计算公式。用这些公式计算的最小电弧短路电流与实验结果吻合。因此，这些公式可用于低压继电保护装置的整定计算，以确保在发生电弧短路时继电保护能可靠动作。     

Simulation of dike-break processes in the Yellow River

Although dike-break and dam-break processes have similar unsteady and discontinuous hydrodynamic characteristics, there are significant differences. In general, dam-break simulations focus on the flood discharge, whereas dike-break simulations are required to provide detailed information on the hydraulic and breach evolution processes, such as pit-scour and breach-expansion. In order to overcome the difficulties inherent in applying existing dam-break models to dike-breaks, this paper presents an integrated model that combines the shallow water, sediment transport, riverbed deformation and breach-expansion equations. A Godunov-type finite volume method is used for the flow simulation, based on a fixed quadtree grid system. The hydro-dynamic aspects of the model are validated for an idealized rectangular dam break. A representative reach in the Yellow River is selected at a location where there is a significant risk of a dike-break, and full-scale topographic and hydrologic data are available. Typical di     

Near miss and minor injury information--can it be used to plan and evaluate injury prevention programmes?

AIM: To assess the usefulness of collecting information on near miss and minor injuries for use in planning and evaluating injury prevention programmes for children aged under 5 years in the home environment. METHOD: The research was set within the context of a controlled intervention study based in 36 general practices across Nottingham. All parents of children aged between 3 and 12 months who had completed the intervention study questionnaire (n = 1594) were used as the sampling frame for the diary study. A diary, developed specifically for the main intervention study, was administered to a systematically assigned sample of 434 parents. Information provided by the Home Accident Surveillance System on 252 randomly selected children, of the same age and sex, who had attended an accident and emergency department, was used to compare the circumstances surrounding near miss and minor injuries with those of medically attended injuries. The children whose parents had completed a diary were followed over a two year time period. The children who had had a medically attended injury were identified from a search of the child's general practice records and the Queens Medical Centre accident and emergency records. The definition of a near miss used in the study was: A near miss incident is something your child does or that happened to your child which could have resulted in him/her being hurt, but fortunately it did not. RESULTS: Overall two hundred and thirty one (53%) diaries were completed and returned. Three hundred and fifty incidents were recorded of which 207 were near misses and 143 minor injuries. The circumstances surrounding near miss and minor injuries, although not identical when compared to medically attended injuries, were very similar. The relationship between the occurrence of near miss, minor injuries and future medically attended injuries appeared weak, for all categories the negative predictive value was higher than the positive predictive value. CONCLUSION: Although the circumstances surrounding all the incident categories were similar, the numbers were too small to see whether specific injury mechanisms predict future injuries of the same type. It appeared that near miss and minor injuries are of limited use in predicting medically attended injuries, however this hypothesis needs to be tested on a much larger sample.     

Stay on Your Feet Safety Walks Group

The Safety Walks Group is an initiative that evolved from the Stay on Your Feet Program. The strategies used in this program target both behavioural and environmental change and are based on the five areas for action under the Ottawa Charter (WHO, 1986) and Jakarta Declaration (WHO, 1997). The Safety Walks Group addresses the issue of public hazards via the use of a standard checklist covering pedestrian areas, business houses and accommodation. The project provided a forum for seniors to be proactive, working with the authorities to address the issue of public hazards and make the environment safer.     

A probe for the versatile analysis and characterization of N-linked oligosaccharides

A novel fluorescent probe, 3-(acetylamino)-6-aminoacridine (AA-Ac), has been synthesized and its applicability to the analysis of picomole levels of N-linked glycans investigated. AA-Ac was found to be an excellent derivatization reagent for N-linked glycans, giving at least twice the intensity of fluorescence as its predecessor 2-aminoacridone. AA-Ac-labeled glycans were analyzed by both normal and reversed-phase HPLC. They were also amenable to enzymatic sequencing and analysis by MALDI-TOF mass spectrometry, free zone capillary electrophoresis, and capillary electrophoresis/electrospray ionization mass spectrometry.     

Reversed-phase high-performance liquid chromatography combined with on-line UV diode array, FT infrared, and 1H nuclear magnetic resonance spectroscopy and time-of-flight mass spectrometry: application to a mixture of nonsteroidal antiinflammatory drugs

A prototype multiply hyphenated system has been applied to the analysis of a mixture of nonsteroidal antiinflammatory drugs separated by reversed-phase HPLC. Characterization of the model NSAIDs was achieved via a combination of diode array UV, 1H NMR, FT-IR spectroscopy, and time-of-flight mass spectrometry. This combination of spectrometers allowed the collection of UV, 1H NMR, IR, and mass spectra together with atomic composition data enabling almost complete structural characterization to be performed.