不同布置方式220 kV变电所对周围环境的电磁辐射分布

通过对不同布置方式220 kV电压等级变电所在运行中对周围环境产生的工频电场、磁感应强度和无线电干扰的监测分析,了解了不同布置方式220 kV电压等级变电所对周围环境电磁辐射的分布规律.指出在建设220 kV电压等级变电所的同时,只要做好建筑屏蔽和电缆入地等工作,就可以降低对周围环境的电磁辐射影响.     

测量工频电磁场应注意的问题

根据高压输变电线路下工频电磁场测量工作的经验,提出应正确选择电磁辐射测量仪器,注重选择测量点位和高度,减少人为干扰和减小环境因素对测量的影响等,从而提高工频电磁场测量的准确性和可靠性.     

基于IRGA通量箱法的草坪夏季晴天CO_2净交换量日动态

利用红外气体箱式法(Infrared Gas Analyze,IRGA),于2008年8月晴天对福州市马尼拉草坪(Zoysia matrel-la)的生态系统CO2净交换(NEE)和环境因子进行观测,阐明NEE及其组分的昼夜动态变化特征和影响因子。马尼拉草坪NEE的昼夜变化呈现为单峰型曲线,昼间其变化规律较强,夜间呈波动状态。NEE(取绝对值)最大值出现在10:00,最小值出现在16:00左右。太阳辐射、腔室内空气相对湿度和气温与NEE的相关性均为极显著(p<0.01),太阳辐射、腔室内空气相对湿度和5cm土壤温度共同解释NEE速率昼夜变异的89.30%。太阳辐射和腔室内空气相对湿度是影响草坪生态系统CO2净交换量日动态的主导环境因子;其中,太阳辐射可以单独解释NEE速率昼夜变化的79.70%,腔室内空气相对湿度可以单独解释NEE速率昼夜变化的50.40%;夏季晴天草坪生态系统在日尺度上表现为净吸收,平均CO2净交换速率为-4.11μmol/(m2.s)(负值表示吸收),平均日总通量为-0.18 mol/(m2.d)。     

对新疆当前电磁辐射环境管理的认识

随着现代科学技术的进步和发展,在电磁辐射的运用范围越来越广的同时其污染水平也在不断增高,人类生存的环境也在不断受到电磁辐射的影响,加强电磁辐射环境管理已势在必行。通信系统电磁辐射应是新疆当前电磁辐射环境管理的重点。     

Photoenhanced toxicity of a weathered oil onCeriodaphnia dubia reproduction

Traditionally, the toxic effects of petroleum have been investigated by conducting studies in the absence of ultraviolet radiation (UV). Photomediated toxicity is often not considered, and the toxic effects of an oil spill can be grossly underestimated. The toxicity of a weathered oil collected from a monitoring well at an abandoned oil field toCeriodaphnia dubia was examined in the presence of UV. A solar simulator equipped with UVB, UVA, and cool white lamps was used to generate environmentally comparable solar radiation intensities.C. dubia were exposed to six concentrations of water accommodated fractions (WAF) of weathered oil in conjunction with three levels of laboratory simulated UV (Reference = < 0.002 μW/cm²UVB; 3.0 μW/cm² UVA; Low = 0.30 μW/cm² UVB; 75.0 μW/cm² UVA; High = 2.0 μW/cm² UVB; 340.0 μW/cm² UVA) and visible light. Seven day static renewal bioassays were used to characterize WAF/UV toxicity. WAF toxicity significantly (p < 0.05) increased when the organisms were exposed to WAF in the presence of UV. The photoenhanced toxicity of the WAF increased with WAF concentration within each UV regime. Relative to the reference light regime, the average number of neonates from adults exposed to 1.6 mg TPH/L decreased significantly by 20% within the low light regime, and by 60% within the high light regime. These results indicate that organisms exposed to dissolved-phase weathered oil in the presence of environmentally realistic solar radiation, exhibit 1.3–2.5 times greater sensitivity, relative to organisms exposed under traditional laboratory fluorescent lighting.     

Tolerance of an Albino Fish to Ultraviolet-B Radiation

We exposed albino and pigmented medakaOryzias latipes to simulated solar ultraviolet-B (UVB) radiation to determine if albino medaka were less tolerant of UVB radiation than medaka pigmented with melanin. There was no difference in the number of albino and pigmented medaka that died during the exposure period. Spectrophotometric analyses of the outer dorsal skin layers from albino and pigmented medaka indicated that, prior to exposure, both groups of fish had similar amounts of an apparent colorless non-melanin photoprotective substance that appears to protect other fish species from UVB radiation. Our results indicate that albino medaka were as tolerant of UVB radiation as pigmented medaka because they had similar amounts of this photoprotective substance in the outer layers of the skin.     

成都双流机场低能见度发生规律初探

双流机场全年近1／3的日子有低见度天气出现,最多的冬季平均日数达到的总数的80％,而且低能见度有明显的季节变化和日变化。低能见度主要由辐射雾造成。二次低能见度天气为其特点,主是由弱冷空气进入暖湿气团所致。     

电磁辐射场对工业微生物生长的影响

为研究电磁辐射场对微生物细胞的“非热效应”,选用几株工业微生物（产L－精氨酸钝齿棒状杆菌A6,产L－赖氨酸钝齿棒状杆菌LB6和产胞内SOD酶酵母菌S1）进行了初步探讨,试验结果表明,置于2μm-1mm频段电磁场接受辐射处理后的试验样本细胞对热的承受能力提高,表现为在较高温度下细胞生长速度的增加,处于对数生长期的细胞对辐射刺激有更明显的敏感反应,较低pH可以一定程度地强化辐射处理的效果,试验结果还进一步证明了以上效应产生于电磁辐射场的“非热效应”,而不是简单的热效应或微生物的自发突变。     

中国农田生态系统碳净吸收重心移动及其原因

为深入了解我国农田生态系统碳净吸收的区域差异及其原因,本文采用重心模型分析了农田系统碳净吸收重心移动规律,运用C-D生产函数分析了影晌农田系统碳净吸收重心移动的因素,并在此基础上计算了各影响因素对各区域碳净吸收的贡献率,提出了相应的政策建议.结果表明:①我国农田系统碳净吸收重心坐标经度减小较快,纬度波动增加,落实到地理区域上呈向西北方向移动的趋势.东南区与蒙新区是农田系统碳净吸收比重下降和增长速度最快的地区,而西南区已逐渐成为我国农田系统碳净吸收的主要贡献区.②常规投入中土地投入是影响农田系统碳净吸收重心移动的首要因素,资本投入(包括化肥、劳动力)也是重要的影响因素:控制变量中种植结构是主要影响因素,使用权与收益权变量系数显著但影响不大.③各影响因素对区域碳净吸收的贡献存在显著的地区差异,但影响各区域碳净吸收的主要贡献因素为土地、化肥和种植结构.