移动电话的电磁辐射对人体伤害及其预防措施的探讨

随着移动电话的迅速普及 ,由其产生的电磁辐射对人体健康的影响已成为人们关心的热门话题。笔者就移动电话的电磁辐射对人体的伤害及其有关预防措施进行探讨。旨在提醒人们正确使用手机 ,尽量减少手机辐射对人体健康的影响 ,起到宣传教育和指导作用     

GSM移动通信基站电磁辐射污染状况研究

介绍了GSM移动通信基站系统,指出,在进行GSM移动通信基站环境影响分析时,要注意采样点位的设置和测量要求.现场监测结果表明,GSM移动通信基站对环境电磁辐射水平有一定的影响,特别是对50 m内建筑物影响显著,但绝大多数基站基本符合国家有关电磁辐射环境影响标准的要求,在设备正常运行情况下,不会对周围环境造成电磁辐射污染.     

流动污染源的排放控制现状及发展趋势

评述了４种主要的流动污染源即汽车、内燃机车、船舶、航空发动机的排放现状，介绍了欧美及中国为了控制排气污染所采用的排放标准，并阐述了各种流动污染源相应的排放净化措施，指出了流动污染源严格监控的迫切性，并提出了相应的建议。     

GC-MS法测定植物排放的萜烯类化合物

采用流动式采样与气相色谱-质谱联用法研究了意大利撒丁岛Noak’s Ark自然生态区四种主要灌木树种Juniperus phoenicea(腓尼基桧)，Pistacia lentiscus(黄连木)，Phillyrea angustifilia，Chamaerops humilis(欧洲矮棕)的排放速率和排放特征。结果表明，JuniPerus phoenicea(腓尼基桧)，Pistacia lentiscus(黄连本)，Phillyrea angustifilia主要排放萜烯类化合物，其中包括α-蒎烯、β-蒎烯、苎烯、戊花烃、莰烯、β-水芹烯、桧烯、β-香叶烯和3-蒈烯等；Chamaerops humilis(欧洲矮棕)主要排放异戊二烯。在标准条件下(温度30℃，PAR为1000μmo1．m^-2．s^-1)，四种树种的排放速率分别为0.15、2．10、0．20和1．87μg／g(DW)．h。     

Comparison of airborne and terrestrial gamma spectrometry measurements - evaluation of three areas in southern Sweden

The Geological Survey of Sweden (SGU) has been conducting airborne gamma spectrometry measurements of natural radioactivity in Sweden for more than 40 years. Today, the database covers about 80% of the country’s land surface. This article explores the first step of putting this data into use in radioactive source search at ground level. However, in order to be able to use the airborne background measurements at ground level, SGU data must be validated against terrestrial data. In this work, we compare the SGU data with data measured by a portable backpack system. This is done for three different areas in southern Sweden. The statistical analysis shows that a linear relationship and a positive correlation exist between the air and ground data. However, this linear relationship could be revealed only when the region possessed large enough variations in areal activity. Furthermore, the activity distributions measured show good agreement to those of SGU. We conclude that the SGU database could be used for terrestrial background assessment, given that a linear transfer function is established.     

基于移动终端设备的环境现场监测管理系统设计与应用

研究了基于移动终端设备的环境现场监测业务数据采集与管理,构建了面向现场监测业务需求的数据采集、存储和传输的业务流程管理,以及与实验室信息管理系统数据共享交互集成的现场监测业务管理和质量控制信息系统。以上海市环境监测中心的现场监测管理系统为例,展示了多媒体及GPS信息采集、仪器数据采集、监测结果录入、原始表单填报和监测布点等环境现场监测活动在移动终端设备上数据管理的具体应用实现。     

Driver hand-held cellular phone use: a four-year analysis

INTRODUCTION: The use of hand-held cellular (mobile) phones while driving has stirred more debate, passion, and research than perhaps any other traffic safety issue in the past several years. There is ample research showing that the use of either hand-held or hands-free cellular phones can lead to unsafe driving patterns. Whether or not these performance deficits increase the risk of crash is difficult to establish, but recent studies are beginning to suggest that cellular phone use elevates crash risk. METHODS: The purpose of this study was to assess changes in the rate of hand-held cellular phone use by motor-vehicle drivers on a statewide level in Michigan. This study presents the results of 13 statewide surveys of cellular phone use over a 4-year period. Hand-held cellular phone use data were collected through direct observation while vehicles were stopped at intersections and freeway exit ramps. Data were weighted to be representative of all drivers traveling during daylight hours in Michigan. RESULTS: The study found that driver hand-held cellular phone use has more than doubled between 2001 and 2005, from 2.7% to 5.8%. This change represents an average increase of 0.78 percentage points per year. The 5.8% use rate observed in 2005 means that at any given daylight hour, around 36,550 drivers were conversing on cellular phones while driving on Michigan roadways. The trend line fitted to these data predicts that by the year 2010, driver hand-held cellular phone use will be around 8.6%, or 55,000 drivers at any given daylight hour. CONCLUSIONS: These results make it clear that cellular phone use while driving will continue to be an important traffic safety issue, and highlight the importance of continued attempts to generate new ways of alleviating this potential hazard.     

FTF算法应用于扩频信号中BPSK型干扰抑制的探讨

介绍遵循ＬＳ准则的快速横向滤波（ＦＴＦ）算法应用于扩频信号中有附加随机相位ＢＰＳＫ型干扰抑制。模拟结果表明，ＦＴＦ算法比遵循ＬＭＳ准则的可变步长ＬＭＳ（ＶＳＳ）算法有显著的优势。文中给出了模拟结果并进行了分析。     

NUTRIENT MASS BALANCE AND TRENDS,MOBILE RIVER BASIN,ALABAMA, GEORGIA,AND MISSISSIPPI1

ABSTRACT: A nutrient mass balance — accounting for nutrient inputs from atmospheric deposition, fertilizer, crop nitrogen fixation, and point source effluents; and nutrient outputs, including crop harvest and storage — was calculated for 18 subbasins in the Mobile River Basin, and trends (1970 to 1997) were evaluated as part of the U.S. Geological Survey National Water Quality Assessment (NAWQA) Program. Agricultural nonpoint nitrogen and phosphorus sources and urban nonpoint nitrogen sources are the most important factors associated with nutrients in this system. More than 30 percent of nitrogen yield in two basins and phosphorus yield in eight basins can be attributed to urban point source nutrient inputs. The total nitrogen yield (1.3 tons per square mile per year) for the Tombigbee River, which drains a greater percentage of agricultural (row crop) land use, was larger than the total nitrogen yield (0.99 tons per square mile per year) for the Alabama River. Decreasing trends of total nitrogen concentrations in the Tombigbee and Alabama Rivers indicate that a reduction occurred from 1975 to 1997 in the nitrogen contributions to Mobile Bay from the Mobile River. Nitrogen concentrations also decreased (1980 to 1995) in the Black Warrior River, one of the major tributaries to the Tombigbee River. Total phosphorus concentrations increased from 1970 to 1996 at three urban influenced sites on the Etowah River in Georgia. Multiple regression analysis indicates a distinct association between water quality in the streams of the Mobile River drainage basin and agricultural activities in the basin.     

Effects of in vitro exposure to GSM900 electromagnetic field on human erythrocytes

High frequency electromagnetic fields (EMF) are widely used for transmitting of radio and TV signals, in wireless communications, etc. A huge number of people are exposed so the possible risk to human health from telecommunication technologies could be significant even if biological effects are slight. The study of the biological effects of RF EM radiation could contribute to better understanding of the possible health hazards. The levels of released hemoglobin serve as an indicator of hemolysis, caused by increased membrane fragility. This study was designed to investigate the alterations in hemoglobin release after in vitro exposure of human erythrocytes to GSM900 electromagnetic field. Erythrocyte suspensions with two different cell concentrations (hematocrit 20% and 40%) were exposed to EM radiation from GSM mobile phone (carrier frequency 902 MHz, 2 W output power in pulse) for 20 min in two different positions in relation to telephone antenna: Position 1 is in the centre of the major lobe of the azimuth antenna pattern and Position 2 is between major and back lobes. Alterations in hemolysis were registered 0, 10, 20, 30, 40, 50 and 60 min after the treatment. Hemolysis was determined by measuring the absorbance of hemoglobin at 413 nm in the supernatant obtained by centrifuging the suspensions. Hemolysis was expressed as hemoglobin concentration. Our data indicated decrease in the hemoglobin level in irradiated suspensions. The GSM900 EMF exposure probably stabilized erythrocyte membrane and caused reduction in the hemolysis depending on the EMF parameters, on the suspension water content (hematocrit) and on the time elapsed after irradiation.