2014年云南昭通鲁甸6.5级地震灾区雷击风险分析及防御措施研究

地震灾区现场区域环境条件复杂,人员密集程度高,具有雷电灾害防御能力弱、群众防雷避险常识淡薄、防雷设施亟待完善的特点,特别是在雷电高发季节,雷击易造成群体性雷电灾害事件。本文以2014年云南昭通鲁甸6.5级地震灾区为例,在进行现场勘察、闪电监测资料综合分析和数据统计的基础上,开展地震灾区雷电活动时空分布特征研究,探讨不同类型的雷击损害风险对灾区可能造成的影响,针对灾区雷电灾害隐患突出的严峻形势,提出相应的对策措施及建议,为有效防御和减少雷电灾害对地震灾区带来的不利影响和公共安全隐患提供技术依据和决策参考。     

胎盘内多环芳烃分布及源解析研究

探讨多环芳烃在胎盘中的分布,并对其进行源解析。从2012年6月—2013年6月在云南省第一人民医院产科分娩的产妇中随机抽取30例,利用气相色谱-质谱联用仪(GC-MS)检测其胎盘中多环芳烃的含量;比较胎盘的中央部分和边缘部分多环芳烃含量的差异;对多环芳烃进行源解析,探讨其主要来源。胎盘中检测到多种多环芳烃成分;其中2~4个苯环的多环芳烃占总量的90%以上,尤其是萘、苊、芴、菲、蒽、芘、荧蒽的含量较高;萘、苊烯、苊、茚并(1,2,3-c,d)芘、二苯并(a,h)蒽5种多环芳烃在胎盘中央的含量高于边缘,具有显著性差异(P0.05),其他多环芳烃在胎盘中央和边缘的含量无显著性差异(P0.05)。多环芳烃源解析提示80%研究对象体内的多环芳烃主要来自石油产品的燃烧或暴露于石油产品。     

Rapid and simple spectrophotometric determination of persulfate in water by microwave assisted decolorization of Methylene Blue

A rapid and simple method for determination of persulfate in aqueous solution was developed. The method is based on the rapid reaction of persulfate with Methylene Blue(MB) via domestic microwave activation, which can promote the activation of persulfate and decolorize MB quickly. The depletion of MB at 644 nm(the maximum absorption wavelength of MB) is in proportion to the increasing concentration of persulfate in aqueous solution. Linear calibration curve was obtained in the range 0–1.5 mmol/L, with a limit of detection of 0.0028 mmol/L. The reaction time is rapid(within 60 sec), which is much shorter than that used for conventional methods. Compared with existing analytical methods, it need not any additives, especially colorful Fe2+, and need not any pretreatment for samples, such as p H adjustment.     

The relationship between light intensity and nutrient uptake kinetics in six freshwater diatoms

In order to find effective measures to control diatom blooms, a better understanding of the physiological characteristics of nutrient uptake in diatoms is needed. A study of P and Si-uptake kinetics for diatom species from two light regimes was conducted at low (LL), moderate (ML) and high light intensities (HL) (2, 25 and 80 μmol photons/(m²·sec)), respectively. The results showed that P uptake of diatoms was heavily influenced by historic light regimes. P affinity changed with growth and photosynthetic activity. The lowest half saturation constant for P uptake (K_m(P)) was under HL for high-light adapted diatoms while the lowest half-saturation constant for low-light adapted diatoms was observed under LL. The Si half-saturation constant (K_m(Si)) increased with increasing light intensities for pennate diatoms but decreased for centric diatoms. Diatom volumes were correlated with the maximum Si uptake rates (V_m(Si)) at HL and K_m(Si) at ML and HL for six diatom species. Our results imply that when we assess the development of diatom blooms we should consider light intensity and cell volume in addition to ambient Si or P concentration. The relationship between light intensity and P-uptake suggests that we can find suitable methods to control diatom blooms on the basis of reducing phytoplankton activity of P-uptake and photosynthesis simultaneously.     

Sulfide elimination by intermittent nitrate dosing in sewer sediments

The formation of hydrogen sulfide in biofilms and sediments in sewer systems can cause severe pipe corrosions and health hazards, and requires expensive programs for its prevention. The aim of this study is to propose a new control strategy and the optimal condition for sulfide elimination by intermittent nitrate dosing in sewer sediments. The study was carried out based on lab-scale experiments and batch tests using real sewer sediments. The intermittent nitrate dosing mode and the optimal control condition were investigated. The results indicated that the sulfide-intermittent-elimination strategy by nitrate dosing is advantageous for controlling sulfide accumulation in sewer sediment. The oxidation–reduction potential is a sensitive indicator parameter that can reflect the control effect and the minimum N/S(nitrate/sulfide)ratio with slight excess nitrate is necessary for optimal conditions of efficient sulfide control with lower carbon source loss. The optimal control condition is feasible for the sulfide elimination in sewer systems.     

Preparation of steel slag porous sound-absorbing material using coal powder as pore former

The aim of the study was to prepare a porous sound-absorbing material using steel slag and fly ash as the main raw material, with coal powder and sodium silicate used as a pore former and binder respectively. The influence of the experimental conditions such as the ratio of fly ash, sintering temperature, sintering time, and porosity regulation on the performance of the porous sound-absorbing material was investigated. The results showed that the specimens prepared by this method had high sound absorption performance and good mechanical properties, and the noise reduction coefficient and compressive strength could reach 0.50 and 6.5 MPa, respectively. The compressive strength increased when the dosage of fly ash and sintering temperature were raised. The noise reduction coefficient decreased with increasing ratio of fly ash and reducing pore former, and first increased and then decreased with the increase of sintering temperature and time. The optimum preparation conditions for the porous sound-absorbing material were a proportion of fly ash of 50% (wt.%), percentage of coal powder of 30% (wt.%), sintering temperature of 1130°C, and sintering time of 6.0 hr, which were determined by analyzing the properties of the sound-absorbing material.     

东江源头区典型村庄厨余废水水质分析

在东江源头区选取了3个典型村庄,对其厨余废水的水质进行调查分析。结果表明:东江源头区沿江村庄农户家庭厨余废水中TP、NH 3-N和COD浓度远远超过《城镇污水处理厂污染物排放标准》中一级A标准限值,需经进一步处理后排放;夏秋季节,厨余废水中TP、NH 3-N、COD浓度高于春季;村庄的经济发展水平对厨余废水水质有一定影响,经济发展水平高的村庄排放的厨余废水中污染物的浓度较经济水平较低的村庄厨余废水中污染物的浓度低。     

基于可靠性分配的整机加速因子计算方法研究

目的验证长寿命高可靠整机产品的可靠性。方法基于RPN数据的可靠性分配方法,得到子系统在各故障模式下的失效率,接着针对导致各故障模式发生的多种应力,研究温度循环、温度驻留、湿度、振动应力下的加速因子,推导出整机加速因子计算公式,并以某典型电子产品加速试验为例,验证该方法的有效性。结果整机加速因子为322.5,比传统方法计算得到的4.78×105更符合实际情况。结论基于可靠性分配的整机加速因子计算方法为整机可靠性验证提供了合理的理论依据。     

秸秆沼气综合利用项目运营期的环境影响评价研究

根据环境影响评价的方法和导则,分析了秸秆沼气综合利用项目运营期对环境产生的不良影响,预测和评价了运营期的大气、废水和噪声污染.结果表明,运营期排放的废水可以满足《城镇污水处理厂污染物排放标准》(GB 18918-2002)一级A标准;烟(粉)尘、SO2是大气污染物的主要成分,项目高噪设备在厂界四周的噪声叠加值满足噪声排放标准.同时提出了相应的环保措施,总结了此类项目环境影响评价的特点.     

案例城市环境基本公共服务与现状比较研究

日益严重的环境问题带来了越来越多的关注度,同时,以为公众提供良好的环境质量为目标的环境基本公共服务,也逐步进入人们的视野。环境基本公共服务是由政府或主要由政府提供的,保障公民最基本的环境权益的服务,包括环境基本公共硬服务和软服务两大方面,其内涵主要由公众、政府、相关企业三方之间的相互供求关系而决定。以环境基本公共服务的具体承载单元———城市为依托进行案例研究,选取纽约、新加坡、广州三所城市进行环境基本公共服务现状对比,结合中国环境基本公共服务外延性不足和无差别受益性两大特点,为中国加强环境基本公共服务水平提供建设性意见。