NaOH改性活性炭的表面特征及吸附甲醛的性能

研究了NaOH改性活性炭(AC)的表面官能团变化特征及其吸附甲醛的性能.实验结果表明:改性AC表面的羧基、酚羟基、内酯基等官能团均与NaOH发生化学反应;质量分数为30%的NaOH溶液对AC表面的清洗作用最大,能将AC表面的杂质基本清除,此时AC表面羧基、酚羟基、内酯基和羰基浓度均达到最大;NaOH溶液质量分数为30%时,改性AC吸附甲醛的效果最好;改性AC表面酚羟基浓度的大小与改性AC吸附甲醛气体穿透时间的长短呈正比.     

Negative responses of Collembola in a forest soil (Alptal,Switzerland) under experimentally increased N deposition

The response of specific groups of organisms, like Collembola to atmospheric nitrogen (N) deposition is still scarcely known. We investigated the Collembola community in a subalpine forest (Alptal, Switzerland) as subjected for 12 years to an experimentally increased N deposition (+25 on top of ambient 12 kg N ha^?1 year^?1). In the 0–5 cm soil layer, there was a tendency of total Collembola densities to be lower in N-treated than in control plots. The density of Isotomiella minor, the most abundant species, was significantly reduced by the N addition. A tendency of lower Collembola group richness was observed in N-treated plots. The Density-Group index (d_DG) showed a significant reduction of community diversity, but the Shannon–Wiener index (H′) was not significantly affected by the N addition. The Collembola community can be considered as a bioindicator of N inputs exceeding the biological needs, namely, soil N saturation.     

颗粒层非稳态过滤捕集效率的研究

为计算颗粒层非稳态过滤效率,通过改进经典过滤理论模型,考虑颗粒在过滤介质中的沉积,理论推导得出非稳态过滤效率的计算公式,而经典颗粒层过滤效率计算公式仅为此计算公式的特例。因为理论计算公式是隐函数,不便于工程实际应用,所以,在常温条件下,对非稳态过滤时的过滤时间、过滤风速、过滤层厚度、粉尘浓度和颗粒层滤料均粒径等五个因素进行了正交实验研究。采用多元回归的方法得出各影响因素与过滤效率呈显性关系的效率关联计算公式,其计算结果与实验测试结果基本吻合。     

基于Level Set方法的风暴追踪

利用现代计算机技术和信息处理技术,建立灾害性天气预警系统,是对灾害性天气进行识别和预报的最有效手段之一.研究探索风暴运动过程中多普勒雷达图像的数据处理和算法优化,是预警系统工作中的关键技术.基于计算机技术,应用TITAN算法及改进的Level set方法可以较好地实现对雷达图像中风暴体的追踪,提高灾害性天气预警效率.     

成都平原城市群的城市流分析

在西部大开发战略不断深入的宏观背景下,以西部地区代表性的城市群--成都平原城市群为例,运用城市流的方法分析城市群内5个主要城市间的空间相互作用,计算并找出不同城市的基础部门和城市流强度,得出结论：成都平原城市群内城市之间外向服务功能呈现明显的差异,有着较好的错位发展空间;在具体产业表现上,交通运输仓储和邮电通信业发展良好,而房地产业、文化体育和娱乐业和公共管理社会组织发展不均衡;成都的城市流倾向度值表明了其当之无愧地成为成都平原城市群的中心城市;次位城市绵阳面临自身内向性发展不足的问题;城市群内部城市的等级分化明显,城市化水平存在巨大的差距。并提出加强成都平原城市群内部联系的简要建议和未来研究的展望.     

Seasonal distribution and modeling of diesel particulate matter in the Southeast US

The fine and ultra fine size of diesel particulate mater (DPM) are of great health concern and significantly contribute to the overall cancer risk. In addition, diesel particles may contribute a warming effect on the planet's climate. The composition of these particles is composed principally of elemental carbon (EC) with adsorbed organic compounds, sulfate, nitrate, ammonia, metals, and other trace elements. The purpose of this study was to depict the seasonality and modeling of particulate matter in the Southeastern US produced by the diesel fueled sources (DFSs). The modeling results came from four one-month cases including March, June, September, and December to represent different seasons in 2003 by linking Models-3/CMAQ and SMOKE. The 1999 National Emissions Inventory Version 3 (NEI99) was used in this analysis for point, area, and non-road sources, whereas the National Mobile Inventory Model (NMIM) was used to create the on-road emissions. Three urban areas, Atlanta, Birmingham, and Nashville were selected to analyze the DPM emissions and concentrations. Even though the model performance was not very strong, it could be considered satisfactory to conduct seasonal distribution analysis for DPM. Important hourly DPM seasonality was observed in each city, of which higher values occurred at the morning traffic rush hours. The EC contributions of primary DPM were similar for all three sites (~ 74%). The results showed that there is no significant daily seasonality of DPM contribution to PM_2.5 for any of these three cities in 2003. The annual DPM contribution to total PM_2.5 for Atlanta, Nashville, and Birmingham were 3.7%, 2.5%, and 2.2%, respectively.     

Urbanization in China Based on International Comparison： A Discussion with Two Prevalent Views

Two prevalent views are reviewed on China＇s urbanization firstly. Then, this article highlights the characteristics and pattern of urbanization in the world based on the quadrants map, using data of 118 countries or areas. The results indicate that the process of urbanization in the world excluding the data of China has slowed down gradually. A further exploration examines China＇s urbanization process and economic development over time, which reveals that both urbanization level and the level of economic development belong to the low-grade coordination pattern. The low level of urbanization is closely connected with the low level of economic development. Actually, China＇s urbanization gap appeared during 1985-1995, but it has been eliminating this urbanization gap since 1995 as a result of rapid urbanization growing. The complicated realities revealed in this analysis challenge the existing two prevalent views.     

影响儿童呼吸系统病症的混杂因子分析

利用 Logistic回归分析 ,对影响儿童呼吸系统病症的混杂因子进行了分析 ,并在控制了混杂因子后 ,对比数比值(OR)进行了比较 ,发现双亲哮喘和双亲气喘、室内烟雾程度和家长做饭时眼部受刺激频率等因子与儿童呼吸系统健康有比较强的统计关联     

室内燃煤取暖与烟雾程度对呼吸道健康的影响研究

在儿童家庭调查问卷的基础上 ,报告室内燃煤取暖与烟雾污染程度对呼吸系统病症的影响。结果表明家庭燃煤取暖与否、室内空气烟雾程度对儿童及其父母的呼吸系统健康有不利的影响     

空气污染对儿童肺功能指标影响的初步分析

报告中国 4城市 8所小学儿童肺功能指标受室外空气污染影响的结果。以 FVC/预测值 (85% )、FEV1 /预测值(85% )、FEV1 / FVC(实测值之比 ) (80 % )作为判断肺功能指标异常的参考标准 ,并将 8所小学按污染程度分为污染严重和污染较轻两类三组。污染严重组儿童肺功能指标的异常率均比污染较轻组要高。空气的严重污染 ,可使儿童肺功能FVC、FEV1 、FEV1 / FVC异常率的危险程度分别增高 3 0 %～ 78%、52 %～ 86%和 1 0 2 %～ 1 2 7%。异常组儿童的 FVC、FEV1 的平均值约下降 3 3 0～ 4 60 ml,FEV1 / FVC平均值约下降 1 3 %～ 1 5%。说明空气的严重污染对儿童肺功能生长发育可能有不利影响