高空核电磁脉冲对爆炸箔起爆器安全性的影响

目的评估爆炸箔起爆器(EFI)在高空核电磁脉冲下的安全性。方法通过吉赫兹横电磁波室(GTEM)强电磁脉冲模拟系统,开展辐射方式下EFI电极塞在模拟高空核电磁脉冲(HEMP)下的感应电流试验测试。HEMP主要是通过电磁辐射方式在EFI脚线上耦合能量,在爆炸箔上产生感应电流,用光纤场强计监测模拟HEMP的电场强度,并在EFI爆炸箔电极塞脚线上套装电流环,通过示波器监测爆炸箔上的感应电流波形。结果在爆炸箔电极塞两根脚线上分别连接相同长度的导线,按导线长度不同分为5、10、20、30、40、50 cm共6组,使导线成180°状态,EFI的脚线可等效为偶极天线,感应电流随脚线长度增加而增大,两者呈线性关系。结论 EFI在HEMP下的感应电流远小于发火电流,对核电磁脉冲环境具有较高的耐受能力,具有较高的安全性。     

Specific biotests to assess eco-toxicity of biodegradable polymer materials in soil

Eco-toxicity investigation of polymer materials was considered extremely necessary for their potential menace, which was widely use as mulching materials in agricultural. In this study, polyethylene (PE), polystyrene (PS) and synthetic biomaterials-Ecoflex and cellulose were applying into soil cultivated with two potential indicator plants species: oat (Avena sativa) and red radish (Raphanus sativum). Variety of chemical, biochemical parameters and enzyme activity in soil were proved as effective approach to evaluate polymers phytotoxicity in plant-soil mesocosm. The F-value of biomass, pH, heavy metal and electoral conductivity of Raphanus behaved significant different from T0. Significant analysis results indicated biodegradation was fast in PE than PS, besides, heavy metals were dramatically decrease in the end implied the plant absorption may help decrease heavy metal toxicity. The increase value at T2 of Dehydrogenase activity (0.84 higher than average value for Avena & 0.91 higher for Raphanus), Metabolic Index (3.12 higher than average value for Avena & 3.81 higher for Raphanus) means during soil enzyme activity was promoted by biodegradation for its heterotrophic organisms’ energy transportation was stimulated. Statistics analysis was carried on Biplot PC1 (24.2% of the total variance), PC2 (23.2% of the total variance), versus PC3 (22.8% of the total variance), which indicated phosphatase activity and metabolic index was significant correlated, and high correlation of ammonium and protease activity. Furthermore, the effects were more evident in Raphanus treatments than in Avena, suggesting the higher sensitivity of Raphanus to polymers treatment, which indicate biodegradation of polymers in Raphanus treatment has produced intermediate phytotoxic compounds.     

易燃易爆场所雷电灾害风险评估的实践和探讨

根据山东省淄博市博山区雷暴日、闪电时空分布特征,参考IEC62305-2等标准规范,分析加油加气站建设项目所在地大气雷电环境状况和雷电灾害易损性,新增加了雷击火灾、爆炸影响范围评估内容,充分考虑毗邻区域的公共安全问题,最大限度减少雷击人身伤害和财产损失.为技术人员做好易燃易爆场所雷电灾害风险评估提供了可借鉴的技术方法和操作规程,简化风险评估模型,使雷电灾害风险评估分析、计算趋于科学和规范化.强调指出雷击风险评估是防御和减轻雷电灾害的关键环节.各类化工厂、易燃仓储、输送贮存油气、加油加气、烟花爆竹等易燃易爆场所应是雷电灾害风险评估的首要重点领域.     

螺旋群锚在岩土介质中极限抗拔力的试验分析及工程应用

通过室内模型试验 ,初步探讨了在砂土中当螺旋群锚的间距改变时 ,其受力性能的变化 ;通过试验及分析 ;提出了计算螺旋群锚在不同间距时的极限承载力公式 ;同时对螺旋锚在工程安全中的应用进行了分析     

应用高精度磁法测定灵武某煤田自燃区范围

煤层自燃后产生"热剩磁",基于这一理论,运用地面高精度磁测在灵武某煤田对煤田自燃区的边界范围进行圈定.由钻孔验证的结果来看,地面高精度磁测在圈定煤田自燃区边界范围时效果良好.     

Epidemiology of musculoskeletal symptoms among Korean hospital nurses.

We investigated the epidemiology of musculoskeletal symptoms (MSS) among a complete cross-section of 330 nurses from a large Korean hospital, by means of a questionnaire survey (response rate: 97.9%). The prevalence of MSS at any body site was 93.6%, with symptoms most commonly reported at the shoulder (74.5%), lower back (72.4%), neck (62.7%), lower legs (52.1%) and hand/wrist (46.7%). Logistic regression indicated that nurses who undertook manual handling of patients were 7.2 times as likely to report MSS (OR 7.2, 95%CI 1.2-42.3, P = .0275), while nurses suffering from periodic depression experienced a 3.3-fold MSS risk (OR 3.3, 95%CI 1.3-8.3, P = .0104). Overall, our study suggests that Korean nurses incur a very high MSS burden when compared internationally. A greater commitment is needed to improve physical conditions, occupational tasks and psychosocial work issues among nurses in this country.     

秦岭镇旬盆地南羊山组沉积物C/S值与沉积环境

介绍了正常海相硅质细碎屑沉积物有机碳与硫化物硫比值（C／S）的含义。以秦岭镇旬盆地南羊山组不同沉积环境沉积物C／S值为例，讨论了还原环境中活性铁的不足对沉积物C／S值的影响，以及有深部成矿物质参与的沉积物具后期发生流化物化沉积物特征的可能性。     

立窑水泥厂袋式除尘器滤料的选择

立窑水泥厂在主要工艺过程上使用袋式除尘技术治理三种集中排放量最大的大气污染源,针对不同的烟气性质选择不同的滤料,以求取得最佳的治理效果。     

滑坡稳定性的模糊综合评定：以陕西渭南地区重点滑坡为例

本文选用地形地貌、岩性结构、构造、大气降雨、水文地质和人类活动6个定量化的环境因子作为评定滑坡稳定性的标志。利用模糊综合评判方法,对陕西渭南地区数十个滑坡的目前稳定性作了分级判别。按渭南地区的实际情况将其稳定性分为稳定滑坡、较稳定滑坡、不稳定滑坡三级,其结果与实际较为符合。