家用报警系统DIY实例

当前市场上的各种报警系统种类繁多,各类制造商也是比比皆是,消费者可以随心所欲地选择他们喜欢的系统。各类系统之间的差别也非常有限,下面我们来介绍一套报警设备的DIY方案,供读者参考(由Alicia示范)。     

城市空气中多环芳烃定量测定方法

本文发展了一种对城市空气中多环芳烃(PAH)定量测定的方法。该方法可以用极少量溶剂,相当快地完成测定工作。     

天然水、土壤和岩石中金与腐殖质的相互作用(地球化学和分析综述)

对天然水、土壤和岩石中金与腐殖质相互作用的结果及Au一腐殖酸和AUCL-腐殖酸在体系中相互作用的实验资料进行了研究。研究表明，金与腐殖酸有机质形成配合物的过程，乃是表生带中金的迁移和富集机制的一个重要方面，决定了从联质矿石中萃取金的工艺特点，影响到岩石、矿石、土壤和天然水中金的测定准确性，进而对金矿床普查和评价的效率有决定性的影响。     

塞浦路斯的地震危险性

<正> 1 地震危险性评定历史地震危险性评定在塞浦路斯虽处于初始阶段,但并未忽视其重要性。地震危险性评定对结构(如构筑物和大坝)的设计安全性参数确定所起的关键作用已有充分认识。到目前为止,已进行了两个场地的地震危险性评定。第一项是确定一大坝坝址预期最大可能地面加速度(Neophyton,1981),第二项估计尼科西亚老城墙以内地区不同烈度地震过程中人员及财产可能损失(Constantinon,1990),研究结果公布于地质调查局的内部报告上。对市区及近郊的岩土工程编图方面,也做了大量工作。测定了Larnaca镇沿海地区的潜在疑难层,如冲积层和高有机含量沉积层(Michaelides,1988)。在塞浦路斯,尽管全国地震危险性图有震中分布图(公元前180～公元1972年)、具有预期最大地面加速度值的观测烈度带图(公元前180～公元1980)和最大能量释放带图(1901～1972),但至今尚未进行综合地震危险性评定研究。     

Design and validation of a practical index for trauma assessment

In the past 20 years a variety of indices have been suggested for measuring the severity of trauma, however none of them meets the requirement of being a simple and objective instrument that can be utilized efficiently by lay persons and providers of health services without previous experience in triaging. A new system has been proposed which meets this requirement and which has been validated with 197 injured persons at the emergency ward of the Valle University Hospital in Call, Colombia. The instrument showed a high level of concordance with the conventional triaging method and classifies victims into four categories: critical with recovery unlikely, critical but recoverable, moderately serious, and ambulatory. There is discussion on the reliability of this instrument and it is recommended that it be validated with victims from larger disasters. Regardless, it has the advantage of being specific and free of the subjectivity that characterizes other indices.     

The role of socio-economic data in food needs assessment and monitoring

This paper reviews six case studies examined as part of a project to review targetting methodologies employed by non-government organisations in Africa during the 1984-6 food crisis. Most agencies have not yet fully evaluated the role of data in informing policy decisions during their respective emergency programmes. The case studies presented reflect a wide variety of approaches to targetting emergency food aid that are based largely on the use of 'socio-economic' data. The recent emergency relief operations in Africa seem to indicate a change in relief agencies' approaches to the assessment and monitoring of needs of the affected populations. Earlier dependance on nutritional data has given way to an increasing reliance on the use of socio-economic indicators. There was a wide variation in the case studies of the type of indicators collected and utilised in needs assessment and monitoring. There were those who relied almost exclusively on nutritional data to target resources during the 1984-86 African crisis, and others whose experiences during that period lead them to attach more weight to socio-economic data. Other agencies appear to have recognised the problems of relying solely on nutritional data to target food aid during their 1984–86 emergency programmes, and thus more or less abandoned classical anthropometric surveys in their needs assessment and monitoring methodologies during this period. Thus nutritional data has a less significant role in the decision making process than previously had been the case.     

Characterization of atmospheric aerosol (PM10 and PM2.5) from a medium sized city in São Paulo state, Brazil

Air pollution causes deleterious effects on human health with aerosols being among the most polluting agents.The objective of this work is the characterization of the PM_(2.5) and PM_(10) aerosol mass in the atmosphere.The methods of analysis include WD-XRF and EDS.Data were correlated with meteorological information and air mass trajectories(model HYSPLIT)by multivariate analysis.A morphological structural analysis was also carried out to identify the probable sources of atmospheric aerosols in the city of Sao Jose do Rio Preto,Brazil.The mean mass concentration values obtained were 24.54 μg/m~3 for PM_(10),above the WHO annual standard value of 20 μg/m~3 and 10.88 μg/m~3 for PM_(2.5) whose WHO recommended limit is10 μg/m~3.WD-XRF analysis of the samples revealed Si and Al as major components of the coarse fraction.In the fine fraction,the major elements were Al and S.The SEM-FEG characterization allowed identifying the morphology of the particles in agglomerates,ellipsoids and filaments in the PM_(10),besides spherical in the PM_(2.5).The analysis by EDS corroborated WD-XRF results,identifying the crustal elements,aluminosilicates and elements of anthropogenic origin in the coarse fraction.For the fine fraction crustal elements were also identified;aluminosilicates,black carbon and spherical particles(C and O) originating from combustion processes were predominant.The use of multivariate analysis to correlate air mass trajectories with the results of the morpho-structural characterization of the particulate matter allowed confirmation of the complex composition of the particles resulting from the combination of both local and long-distance sources.     

Reactive uptake of NO2 on volcanic particles: A possible source of HONO in the atmosphere

The heterogeneous degradation of nitrogen dioxide (NO₂) on five samples of natural Icelandic volcanic particles has been investigated. Laboratory experiments were carried out under simulated atmospheric conditions using a coated wall flow tube (CWFT). The CWFT reactor was coupled to a blue light nitrogen oxides analyzer (NO_x analyzer), and a long path absorption photometer (LOPAP) to monitor in real time the concentrations of NO₂, NO and HONO, respectively. Under dark and ambient relative humidity conditions, the steady state uptake coefficients of NO₂ varied significantly between the volcanic samples probably due to differences in magma composition and morphological variation related with the density of surface OH groups. The irradiation of the surface with simulated sunlight enhanced the uptake coefficients by a factor of three indicating that photo-induced processes on the surface of the dust occur. Furthermore, the product yields of NO and HONO were determined under both dark and simulated sunlight conditions. The relative humidity was found to influence the distribution of gaseous products, promoting the formation of gaseous HONO. A detailed reaction mechanism is proposed that supports our experimental observations. Regarding the atmospheric implications, our results suggest that the NO₂ degradation on volcanic particles and the corresponding formation of HONO is expected to be significant during volcanic dust storms or after a volcanic eruption.     

用广义λ—分布拟合空气污染数据

广义λ-分布是一个四参数可变通的概率模型,包括多种单变量分布,这一模型可用于表示空气污染浓度的频率分布。本文采用土耳其安卡拉每日的烟和SO_2监测数据,来证明广义λ-分布具有良好的拟合性质。这里还讨论了与分位数估计和拟合优度有关的一些结果,并与经典对数正态分布进行了比较。     

Mobilization of aluminium and deposition on fish gills during sea salt episodes--catchment liming as countermeasure

Episodic events may be critical with respect to aluminium (Al) toxicity in moderately acidified salmon rivers. The present work demonstrates that sea salt episodes enhance the toxicity of Al in acidic rivers. The documented sea salt episode (300 [micro sign]M Cl) mobilized positively charged Al species (0.4 to 1.1 [micro sign]M Al(i)), enhanced the Al accumulation on fish gills (0.9 to 10 [micro sign]mol g(-1) dw) and caused increased stress responses (6 to15 mM blood glucose) in fish. Accumulated Al on gills remained high several days after the episode. The presented results are based on a six-week field study in two tributary rivers on the west coast of Norway. Changes in the river water qualities and Al speciation were followed using in situ fractionation techniques. Al accumulation on gills and stress responses were followed for Atlantic salmon (Salmo salar) kept in tanks continually exposed to the changing water quality. The potential mobilization of Al from the two catchments was studied by extracting soils with diluted seawater (salinity of 3). To counteract Al toxicity, one of the tributary catchments has been limed. The potential mobility of Al by sea salt was lower in limed soils compared to acid soils, and the Al deposition on fish gills (<3.5 [micro sign]mol g(-1) dw) and associated stress responses stayed low during the sea salt episode in the river draining the limed catchment. Thus, for acid river systems in coastal areas, catchment liming should be considered as a useful countermeasure for Al toxicity.